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In vivo and in vitro effects of the mycotoxins zearalenone and deoxynivalenol on different non-reproductive and reproductive organs in female pigs: A review
Abstract
This review summarizes the toxicological data on the effects of the mycotoxins zearalenone (ZON), its metabolites, and deoxynivalenol (DON) on different parameters relating to reproductive and non-reproductive organs in female pigs. In vivo, 22 mg ZON kg-1 in the diet cause alterations in the reproductive tract of swine such as in the uterus, and affects follicular and embryo development. ZON and its metabolites have been shown to bind competitively to oestrogen receptors in an in vitro system. The feeding of pigs with a 9 mg DON kg-1-contaminated diet can act on protein synthesis, humoral and cellular immune response depending on dose, exposure and timing of functional immune assay, and affect liver and spleen cell structures. Beside these effects, reproductive alterations were observed in pigs, too. Both in vivo and in vitro exposure to DON decreased oocyte and embryo development. In vitro application of DON to uterine cells inhibits their proliferation rate and modulates the process of translation at a different molecular level when compared with the in vivo application. The histopathological results provide evidence of spleen and liver dysfunction in the absence of clinical signs, especially in pigs fed higher concentrations of Fusarium toxin-contaminated wheat. Prepuberal gilts react more sensitively to DON > ZON feeding compared with pregnant sows. In the liver, histopathological changes such as glycogen decrease and interlobular collagen uptake were only observed in prepuberal gilts, whereas enhancement of haemosiderin was found in both perpuberal gilts and pregnant sows. This review presents some of the current knowledge on the biological activities of ZON and DON in pig. Altogether, ZON affects reproduction of pigs most seriously because it possesses oestrogenic activity. However, DON affects reproduction in pigs via indirect effects such as reduced feed intake, resulting in reduced growth or impairment of function in vital organs such as liver and spleen.
... DON, 3-ADON, and 15-ADON belong to the type-B trichothecenes produced by Fusarium graminearum and Fusarium asiaticum, which can cause hepatotoxicity, nephrotoxicity, neurotoxicity, and immunotoxicity in mammals [12,13]. DON, 3-ADON, and 15-ADON can contaminate agro-products such as wheat, maize, and even occur in agricultural commodities across the food chain. ...
... Stock standard solutions of DON, 3-ADON, and 15-ADON, in acetonitrile with concentrations of 100.0, 100.0, and 100.0 mg/L, respectively, were purchased from Romer-labs (Tulln, Austria) and stored at −20 °C. 13 C-DON (stable isotope-labelled internal standard, 50.0 μg/ml) and 13 C-3-ADON (stable isotope-labelled internal standard, 25.0 μg/ml) stock solutions in acetonitrile were purchased from Romer-labs (Tulln, Austria). The working standard solutions were prepared in the mobile phase and kept at 4 °C. ...
... All organic solvents, including acetonitrile and methanol used for sample extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis, were LC/MS grade and purchased from Fisher Scientific. Stock standard solutions of DON, 3-ADON, and 15-ADON, in acetonitrile with concentrations of 100.0, 100.0, and 100.0 mg/L, respectively, were purchased from Romer-labs (Tulln, Austria) and stored at −20 • C. 13 C-DON (stable isotope-labelled internal standard, 50.0 µg/ml) and 13 C-3-ADON (stable isotope-labelled internal standard, 25.0 µg/ml) stock solutions in acetonitrile were purchased from Romer-labs (Tulln, Austria). The working standard solutions were prepared in the mobile phase and kept at 4 • C. Wheat and maize reference materials for DON were purchased from Biopure (Tulln, Austria). ...
Deoxynivalenol (DON), along with 3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON), occur in grains and cereal products and is often hazardous to humans and livestock. In this study, 579 wheat samples and 606 maize samples intended for consumption were collected from China in 2017 and analyzed to determine the co-occurrence of type-B trichothecenes (DON, 3-ADON, and 15-ADON). All the wheat samples tested positive for DON, while 99.83% of the maize samples were DON-positive with mean DON concentrations of 165.87 and 175.30 μg/kg, respectively. Per the Chinese standard limits for DON, 3.63% of wheat and 2.97% of the maize samples were above the maximum limit of 1000 μg/kg. The DON derivatives (3-ADON and 15-ADON) were less frequently found and were present at lower levels than DON in wheat. 3-ADON and 15-ADON had incidences of 13.53% and 76.40%, respectively, in maize. By analyzing the distribution ratio of DON and its derivatives in wheat and maize, DON (95.51%) was the predominant toxin detected in wheat samples, followed by 3.97% for the combination of DON + 3-ADON, while DON + 3-ADON + 15-ADON and DON + 15-ADON were only found in 0.17% and 0.35% of wheat samples, respectively. Additionally, a large amount of the maize samples were contaminated with DON + 15-ADON (64.19%) and DON (22.11%). The samples with a combination of DON + 3-ADON and DON + 3-ADON + 15-ADON accounted for 1.32% and 12.21%, respectively. Only one maize sample did not contain all three mycotoxins. Our study shows the necessity of raising awareness of the co-occurrence of mycotoxin contamination in grains from China to protect consumers from the risk of exposure to DON and its derivatives.
... Other fungi that have been isolated as poultry feed contaminants are Trichosporium , Stachybotrys (Labuda and Tancinová, 2006), Trichoderma (Heperkan and Alperden, 1988) among others (Table 1). These fungi have been linked with the production of different mycotoxins (Tiemann and Dänicke, 2007;Rodrigues and Naehrer, 2012;Queiroz et al., 2013). Mycotoxigenic fungi are capable of producing more than one mycotoxin in feed because many different species of fungi develop in the feed at the same time, especially in feed prepared using multiple feed ingredients (Streit et al., 2012). ...
... OTA is an important mycotoxin in poultry nutrition produced by Penicillium and Aspergillus species (Hassan et al., 2012). ZEN mycotoxins or F-2 toxins are produced by Fusarium species and they occur as natural mycotoxin contaminant in corn, wheat, barley, oats and sorghum (Tiemann and Dänicke, 2007;Rodrigues and Naehrer, 2012). ZEN is produced by different strains of Fusaria, F. avenaceum, F. equiseti, F. gravinearum, F. culmorum, F. lateritium (Shi et al., 2016). ...
Poultry feeds are made with ingredients from different raw materials; therefore contamination with microbial agents is very common. When contaminated poultry feeds are consumed by birds, they may serve as reservoirs for many human pathogens. Bacterial pathogens seem to be the most prevalent, viral and fungal pathogens are also hazardous in poultry feeds. When microorganisms colonize poultry feeds, they utilize the readily available nutrients in the feed, thereby reducing its nutritional quality. Therefore, information on the diversity of microbial contaminants in feeds is important in designing effective feed monitoring and hazard control strategies. Some of the established contaminants of poultry feeds are bacterial and fungal agents and their secretory products. These microbes are released in the feed through raw feed ingredients, stored feed products, during feed processing and handling as well as through other environmental sources. Contaminated poultry feed adversely affects feed intake, feed conversion ratio, weight gain, organ function and alters blood and clinical chemistry parameters of birds. This review provides background information on the various microbes that contaminate poultry feeds, their sources, the adverse impacts on the health and performance parameters of birds as well as their control strategies.
... Other fungi that have been isolated as poultry feed contaminants are Trichosporium , Stachybotrys (Labuda and Tancinová, 2006), Trichoderma (Heperkan and Alperden, 1988) among others (Table 1). These fungi have been linked with the production of different mycotoxins (Tiemann and Dänicke, 2007;Rodrigues and Naehrer, 2012;Queiroz et al., 2013). Mycotoxigenic fungi are capable of producing more than one mycotoxin in feed because many different species of fungi develop in the feed at the same time, especially in feed prepared using multiple feed ingredients (Streit et al., 2012). ...
... OTA is an important mycotoxin in poultry nutrition produced by Penicillium and Aspergillus species (Hassan et al., 2012). ZEN mycotoxins or F-2 toxins are produced by Fusarium species and they occur as natural mycotoxin contaminant in corn, wheat, barley, oats and sorghum (Tiemann and Dänicke, 2007;Rodrigues and Naehrer, 2012). ZEN is produced by different strains of Fusaria, F. avenaceum, F. equiseti, F. gravinearum, F. culmorum, F. lateritium (Shi et al., 2016). ...
Poultry feeds are made with ingredients from different raw materials; therefore contamination with microbial agents is very common. When contaminated poultry feeds are consumed by birds, they may serve as reservoirs for many human pathogens. Bacterial pathogens seem to be the most prevalent, viral and fungal pathogens are also hazardous in poultry feeds. When microorganisms colonize poultry feeds, they utilize the readily available nutrients in the feed, thereby reducing its nutritional quality. Therefore, information on the diversity of microbial contaminants in feeds is important in designing effective feed monitoring and hazard control strategies. Some of the established contaminants of poultry feeds are bacterial and fungal agents and their secretory products. These microbes are released in the feed through raw feed ingredients, stored feed products, during feed processing and handling as well as through other environmental sources. Contaminated poultry feed adversely affects feed intake, feed conversion ratio, weight gain, organ function and alters blood and clinical chemistry parameters of birds. This review provides background information on the various microbes that contaminate poultry feeds, their sources, the adverse impacts on the health and performance parameters of birds as well as their control strategies.
... Other fungi that have been isolated as poultry feed contaminants are Trichosporium , Stachybotrys (Labuda and Tancinová, 2006), Trichoderma (Heperkan and Alperden, 1988) among others (Table 1). These fungi have been linked with the production of different mycotoxins (Tiemann and Dänicke, 2007;Rodrigues and Naehrer, 2012;Queiroz et al., 2013). Mycotoxigenic fungi are capable of producing more than one mycotoxin in feed because many different species of fungi develop in the feed at the same time, especially in feed prepared using multiple feed ingredients (Streit et al., 2012). ...
... OTA is an important mycotoxin in poultry nutrition produced by Penicillium and Aspergillus species (Hassan et al., 2012). ZEN mycotoxins or F-2 toxins are produced by Fusarium species and they occur as natural mycotoxin contaminant in corn, wheat, barley, oats and sorghum (Tiemann and Dänicke, 2007;Rodrigues and Naehrer, 2012). ZEN is produced by different strains of Fusaria, F. avenaceum, F. equiseti, F. gravinearum, F. culmorum, F. lateritium (Shi et al., 2016). ...
... Pigs are particularly susceptible to ZEN. ZEN can cause hyperestrogenism and impair reproductive function in this species [6,7]. Furthermore, ZEN may affect gut health and the immune system in pigs [8][9][10][11]. ...
... Rainbow trout (Oncorhynchus mykiss) have been shown to be sensitive to dietary ZEN in recent studies. ZEN can cause hyperestrogenism and impair reproductive function in this species [6,7]. Furthermore, ZEN may affect gut health and the immune system in pigs [8][9][10][11]. ...
The estrogenic mycotoxin zearalenone (ZEN) is a common contaminant of animal feed. Effective strategies for the inactivation of ZEN in feed are required. The ZEN-degrading enzyme zearalenone hydrolase ZenA (EC 3.1.1.-, commercial name ZENzyme®, BIOMIN Holding GmbH, Getzersdorf, Austria) converts ZEN to hydrolyzed ZEN (HZEN), thereby enabling a strong reduction in estrogenicity. In this study, we investigated the efficacy of ZenA added to feed to degrade ZEN in the gastrointestinal tract of three monogastric animal species, i.e., pigs, chickens, and rainbow trout. For each species, groups of animals received (i) feed contaminated with ZEN (chickens: 400 µg/kg, pigs: 200 µg/kg, rainbow trout: 2000 µg/kg), (ii) feed contaminated with ZEN and supplemented with ZenA, or (iii) uncontaminated feed. To investigate the fate of dietary ZEN in the gastrointestinal tract in the presence and absence of ZenA, concentrations of ZEN and ZEN metabolites were analyzed in digesta of chickens and rainbow trout and in feces of pigs. Upon ZenA administration, concentrations of ZEN were significantly decreased and concentrations of the degradation product HZEN were significantly increased in digesta/feces of each investigated animal species, indicating degradation of ZEN by ZenA in the gastrointestinal tract. Moreover, upon addition of ZenA to the diet, the concentration of the highly estrogenic ZEN metabolite α-ZEL was significantly reduced in feces of pigs. In conclusion, ZenA was effective in degrading ZEN to HZEN in the gastrointestinal tract of chickens, pigs, and rainbow trout, and counteracted formation of α-ZEL in pigs. Therefore, ZenA could find application as a ZEN-degrading feed additive for these animal species.
... Previous research has documented that high concentrations of ZEA (250-5000 μg/kg) can cause vulva swelling in prepubertal gilts [27,36,37]. Similarly, several studies also indicated that ZEN resulted in vulvar swelling and vaginal prolapse [20,38]. ...
... This indicated that uterus and ovary may be the main target organ for ZEA. Although ERα in the uterus was not affected, gilts fed ZEA diets (1500 μg/kg) had 2.0-3.5 fold higher ERβ mRNA and protein abundance in prepubertal gilts [37]. On the contrary, 500-2000 μg/kg ZEA increased ERα levels in uterus and vagina but decreased ERβ levels in the gilts [42]. ...
Background
Zearalenone (ZEA) is a resorcylic acid lactone derivative derived from various Fusarium species that are widely found in food and feeds. The molecular structure of ZEA resembles that of the mammalian hormone 17β-oestradiol, thus zearalenone and its metabolites are known to compete with endogenous hormones for estrogen receptors binding sites and to activate transcription of oestrogen-responsive genes. However, the effect of long-term low-dose ZEA exposure on the reproductive response to Bacillus subtilis ANSB01G culture for first-parity gilts has not yet been investigated. This study was conducted to investigate the toxic effects of ZEA as an estrogen receptor selective modulator and the alleviating effects of Bacillus subtilis ANSB01G cultures as ZEA biodegraders in pregnant sows during their first parity.
Results
A total of 80 first-parity gilts (Yorkshire × Landrace) were randomly assigned to four dietary treatments during gestation: CO (positive control); MO (negative control, 246 μg ZEA/kg diet); COA (CO + B. subtilis ANSB01G culture with 2 × 10 ⁹ CFU/kg diet); MOA (MO + B. subtilis ANSB01G culture with 2 × 10 ⁹ CFU/kg diet). There were 20 replications per treatment with one gilt per replicate. Feeding low-dose ZEA naturally contaminated diets disordered most of reproductive hormones secretion and affected estrogen receptor-α and estrogen receptor-β concentrations in serum and specific organs and led to moderate histopathological changes of gilts, but did not cause significant detrimental effects on reproductive performance. The addition of Bacillus subtilis ANSB01G culture to the diet can effectively relieve the competence of ZEA to estrogen receptor and the disturbance of reproductive hormones secretion, and then ameliorate toxicosis of ZEA in gilts.
Conclusions
Collectively, our study investigated the effects of feeding low-dose ZEA on reproduction in pregnant sows during their first parity. Feeding low-dose ZEA could modulate estrogen receptor-α and -β concentrations in specific organs, cause disturbance of reproductive hormones and vulva swelling, and damage organ histopathology and up-regulate apoptosis in sow models. Diet with Bacillus subtilis ANSB01G alleviated negative effects of the ZEA on gilts to some extent.
... Reduced feed intake and reduced body weight gain were the most relevant chronic adverse effects of DON in pigs. However, DON may cause several other adverse effects in pigs, including lesions in the stomach's oesophageal region, the liver, the lungs and the kidneys, and changes in different clinical chemistry parameters (plasma nutrients and plasma enzyme activities) [26]. The feeding of contaminated feed containing DON and decreasing food intake can influence the immune responses in pigs. ...
... ZEN can cause different harmful health effects in pigs. Mainly reported alterations of fertility and reproduction [26]. This effect results from the capacity of ZEN to bind the oestrogen receptors [41]. ...
Farm animals are frequently exposed to mycotoxins, which have many adverse effects on their health and become a significant food safety issue. Pigs are highly exposed and particularly susceptible to mycotoxins, which can cause many adverse effects. For the above reasons, an appropriate diagnostic tool is needed to monitor pig’ exposure to mycotoxins. The most popular tool is feed analysis, which has some disadvantages, e.g., it does not include individual exposure. In recent years, the determination of biomarkers as a method to assess the exposure to mycotoxins by using concentrations of the parent compounds and/or metabolites in biological matrices is becoming more and more popular. This review provides a comprehensive overview of reported in vivo mycotoxin absorption, distribution, metabolism and excretion (ADME) and toxicokinetic studies on pigs. Biomarkers of exposure for aflatoxins, deoxynivalenol, ochratoxin A, fumonisins, T-2 toxin and zearalenone are described to select the most promising compound for analysis of porcine plasma, urine and faeces. Biomarkers occur in biological matrices at trace levels, so a very sensitive technique—tandem mass spectrometry—is commonly used for multiple biomarkers quantification. However, the sample preparation for multi-mycotoxin methods remains a challenge. Therefore, a summary of different biological samples preparation strategies is included in that paper.
... Significant economic losses in pork production also result from the influence of DON on reproductive performance [19][20][21] when the developing fetus is exposed due to pregnant sows ingesting a toxin-contaminated diet [22,23]. However, a subsequent detailed study showed that no pathomorphologically or immunohistochemically detectable alterations occur in fetal organs after intrauterine transfer of DON [24]. ...
... Biochemical analysis of the plasma ALT and AST levels did not show increased levels in comparison to the reference values. The reference values for determining increased levels of enzymes were 1.428 and 0.986 µkat/L for AST and ALT, respectively [19]. This means that the levels of both enzymes did not exceed the limits, implying that no liver damage had occurred. ...
Deoxynivalenol (DON)-contaminated feed represents a serious problem for pigs due to their high sensitivity to its toxicological effects. The aim of the present study was to evaluate the impact of intrauterine DON exposure on the immune system of piglets. Pure DON was intravenously administered to sows at the end of gestation (during the last 2–3 days of gestation, one dose of 300 µg per day). The plasma concentration of DON was analyzed using liquid chromatography combined with high-resolution Orbitrap-based mass spectrometry (LC–MS/MS (HR)) and selected immune parameters were monitored six times in piglets from birth to 18 weeks. DON was found in the plasma of 90% of newborn piglets at a mean concentration of 6.28 ng/mL and subsequently, at one, three, and seven weeks after birth with decreasing concentrations. Trace amounts were still present in the plasma 14 weeks after birth. Flow cytometry revealed a significant impact of DON on T lymphocyte subpopulations during the early postnatal period. Lower percentages of regulatory T cells, T helper lymphocytes, and their double positive CD4+CD8+ subset were followed by increased percentages of cytotoxic T lymphocytes and γδ T cells. The capacity to produce pro-inflammatory cytokines was also significantly lower after intrauterine DON exposure. In conclusion, this study revealed a long-term persistence of DON in the plasma of the piglets as a consequence of short-term intrauterine exposure, leading to altered immune parameters.
... Zearalenone (ZON) is one of several stable mycotoxins produced by Fusarium species which contaminates a variety of forages and cereals such as barley, corn, oats, sorghum, soy, and wheat (1,2), and has been recently found in sugar beet pulp, a feedstuff often used as horse feed (3). Literature reports of hyperestrogenism, reproductive disruptions, and fetal abnormalities as a result of unintentional or intentional feeding of mycotoxin-contaminated feed have been recorded in numerous species (4)(5)(6)(7). Often mycotoxin contaminated feed contains a mixture of compounds such as ZON, deoxynivalenol (DON), and T-2 toxins, among others, and deciphering the contribution of each individually or in synergism with each other is of interest (4). ZON and its derivatives α-and β-zearalenol (ZOL) are known to have affinity for estrogen receptors (8)(9)(10) and elicit a proliferative response in estrogen responsive tissues in vitro (11,12). ...
... The literature has multiple reports of the effects of ZON on reproduction in livestock [for review (6)], and often refers to the species sensitivity of pigs and other animals. However, the number of studies addressing the effect of ZON on reproduction in horses is extremely limited, consisting of two reports, in which the most alarming described a natural outbreak of ZON mycotoxicosis in 1983 (20), and three in vivo studies with control and treated mares (23,24,35) of which only one (Juhász) used only ZON, rather than a mixture of ZON and deoxynivalenone (DON) or a suite of toxins in contaminated feed. ...
It is known that zearalenone (ZON) interacts directly with estrogen receptors, and its in vivo effects on reproduction have been well-documented in several species. In contrast, reports of ZON's impact on horse reproduction are conflicting and inconclusive, some studies confounded by the presence of mycotoxins such as deoxynivalenol in the feed. This study assesses the effect of chronic consumption of zearalenone on reproduction in cycling mares fed >95% pure ZON (0, 2, or 8 mg/da; n = 7 mares/treatment) for three estrous cycles, followed by artificial insemination, through 16 days of pregnancy. Animals were on ZON treatment for between 70 and 121 days (average 84) depending on individual cycle patterns. ZON-induced changes in serum concentration of estradiol (E2) and progesterone (P4), and total estrogenicity were measured using RIAs and the E-screen assay, respectively. Effects on reproductive physiology and pregnancy were monitored by ultrasound and clinical parameters. No significant changes were found in reproductive hormone levels of E2, or P4 for mares on ZON treatments compared to controls, although there was a significant (P < 0.01) increase in P4 levels across Cycle number in High ZON (8 mg/da) treated mares. There was also an increasing trend in the interovulatory interval in the High ZON treatment group. The overall estrogenicity was similar across treatments and over time, not differing from controls or between ZON treatment groups. Adverse uterine and ovarian effects were also not observed, but pregnancy rates were mixed with only 4 of 7 mares on Low ZON becoming pregnant, and only 3 maintaining pregnancy and fetal heartbeat by Day 30, compared to 5 of 6 control mares and all 7 mares on High ZON. Because reproductive efficiency and hormone concentrations are highly variable across individuals, this study did not demonstrate that ZON at 2 or 8 mg/da was detrimental to mares' reproduction. Yet, inferring that ZON treatments were completely without effect is also not appropriate, as the absence of measurable significant differences could be attributed to the limited sample size. Most importantly, there were no extreme signs of toxicology, in contrast to previous reports when ZON was fed at these “doses.”
... ZEN is classified as a non-steroidal estrogenic mycotoxin due to its ability to exert effects similar to those of estrogens [4,5]. Its toxicity has been associated with reduced fertility and litter size, uterine enlargement, changes in serum levels of progesterone and estradiol in laboratory animals, as well as alterations in fertility and reproduction in pigs [6][7][8][9]. Pigs are particularly sensitive to ZEN but also highly sensitive to DON [10][11][12]. Low-dose exposure to DON affects the intestinal barrier and the intestinal immune system, which may significantly impact pig health and performance [13][14][15][16]. ...
Mycotoxin binders, in combination with enzymes degrading some mycotoxins, contribute to feed detoxification. Their use reduces economic losses and the negative impacts of mycotoxins on animal health and productivity in farm animals. The aim of this study was to evaluate the efficacy of a mycotoxin detoxifier on the expression of the ATP-binding cassette efflux transporters ABCB1 mRNA and ABCC2 mRNA, which transport xenobiotics and thus have a barrier function, in the tissues of pigs exposed to low doses of deoxynivalenol (DON, 1 mg/kg feed) and zearalenone (ZEN, 0.4 mg/kg feed) for 37 days. The levels of expression were determined by an RT-PCR, and the effect of the mycotoxin detoxifier (Mycofix Plus3.E) was evaluated by a comparison of results between healthy pigs (n = 6), animals treated with DON and ZEN (n = 6), and a group that received both mycotoxins and the detoxifier (n = 6). A significant downregulation of ABCB1 mRNA and ABCC2 mRNA was observed in the jejunum (p < 0.05). A tendencies toward the downregulation of ABCB1 mRNA and ABCC2 mRNA were found in the ileum and duodenum, respectively. The mycotoxin detoxifier restored the expression of ABCB1 mRNA to the level found in healthy animals but did not restore that of ABCC2 mRNA to the level of healthy animals in the jejunum.
... The supplementation of feed with DON can have varied effects on protein synthesis and humoral and cellular immune responses in pigs, contingent on the timing, exposure, and functional immunoassay, concurrently altering the cellular structure of the liver and spleen. Moreover, reproductive changes have also been observed in pigs, and DON reduces oocyte and embryo development both in vivo and in vitro [19]. DON upregulates mitochondrial pathway apoptosis-related protein expression levels in mouse ESCs to induce apoptosis [20]. ...
Zearalenone (ZEA) and deoxynivalenol (DON) are widely found in various feeds, which harms livestock’s reproductive health. Both mitochondria and endoplasmic reticulum (ER) can regulate cell apoptosis. This study aimed to explore the regulatory mechanism of endoplasmic reticulum stress (ERS) on ZEA- combined with DON-induced mitochondrial pathway apoptosis in piglet Sertoli cells (SCs). The results showed that ZEA + DON damaged the ultrastructure of the cells, induced apoptosis, decreased mitochondrial membrane potential, promoted the expression of cytochrome c (CytC), and decreased the cell survival rate. Furthermore, ZEA + DON increased the relative mRNA and protein expression of Bid, Caspase-3, Drp1, and P53, while that of Bcl-2 and Mfn2 declined. ZEA + DON was added after pretreatment with 4-phenylbutyric acid (4-PBA). The results showed that 4-PBA could alleviate the toxicity of ZEA + DON toward SCs. Compared with the ZEA + DON group, 4-PBA improved the cell survival rate, decreased the apoptosis rate, inhibited CytC expression, and increased mitochondrial membrane potential, and the damage to the cell ultrastructure was alleviated. Moreover, after pretreatment with 4-PBA, the relative mRNA and protein expression of Bid, Caspase-3, Drp1, and P53 were downregulated, while the relative mRNA and protein expression of Bcl-2 and Mfn2 were upregulated. It can be concluded that ERS plays an important part in the apoptosis of SCs co-infected with ZEA-DON through the mitochondrial apoptosis pathway, and intervention in this process can provide a new way to alleviate the reproductive toxicity of mycotoxins.
... Among the diversity of farm animals, pigs are especially sensitive to DON due to bioavailability and rapid absorption [3,5]. DON has been known to damage vital organs, including the small intestine, kidney, spleen, and liver, through inflammation, oxidative stress, apoptosis, cell cycle arrest in the G2/M cell cycle phase, and cell signaling deregulation [6][7][8]. DON induces the dysfunction of protein and nucleic acid biosynthesis by binding to ribosomes, resulting in negative effects on cells. The small intestine and liver are organs with high protein turnover; therefore, these are mainly targeted by the cytotoxicity of DON [9]. ...
Deoxynivalenol (DON) is known as a vomitoxin, which frequently contaminates feedstuffs, such as corn, wheat, and barley. Intake of DON-contaminated feed has been known to cause undesirable effects, including diarrhea, emesis, reduced feed intake, nutrient malabsorption, weight loss, and delay in growth, in livestock. However, the molecular mechanism of DON-induced damage of the intestinal epithelium requires further investigation. Treatment with DON triggered ROS in IPEC-J2 cells and increased the mRNA and protein expression levels of thioredoxin interacting protein (TXNIP). To investigate the activation of the inflammasome, we confirmed the mRNA and protein expression levels of the NLR family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and caspase-1 (CASP-1). Moreover, we confirmed that caspase mediates the mature form of interleukin-18, and the cleaved form of Gasdermin D (GSDMD) was increased. Based on these results, our study suggests that DON can induce damage through oxidative stress and pyroptosis in the epithelial cells of the porcine small intestine via NLRP3 inflammasome.
... Thus, feeding pigs contaminated feed with several types of mycotoxins, even if they are in concentrations at the minimum recommended by the European Union, can cause numerous negative effects in animals due to cumulative toxic effects. The most common symptoms of mycotoxicosis in swine are the refusal to eat, decrease in growth rate, reproductive disorders and decreased immune status [88][89][90][91][92]. In the process of breeding and producing pigs about 60-70% of the costs are due to feed [93]. ...
Feeding farm animals with aflatoxin-contaminated feed can cause various severe toxic effects, leading to increased susceptibility to infectious diseases and increased mortality, weight loss, poor performance and reduced reproductive capability. Following ingestion of contaminated foodstuffs, aflatoxins are metabolized and biotransformed differently in animals. Swine metabolism is not effective in detoxifying and excreting aflatoxins, meaning the risk of aflatoxicosis is increased. Thus, it is of great importance to elucidate the metabolism and all metabolic pathways associated with this mycotoxin. The damage induced by AFB1 in cells and tissues consists of inhibition of cell proliferation, carcinogenicity, immunosuppression, mutagenicity, oxidative stress, lipid peroxidation and DNA damage, leading to pathological lesions in the liver, spleen, lymph node, kidney, uterus, heart, and lungs of swine. At present, it is a challenging task and of serious concern to completely remove aflatoxins and their metabolites from feedstuff; thus, the aim of this study was a literature review on the deleterious effects of aflatoxins on swine metabolism, as well as alternatives that contribute to the detoxification or amelioration of aflatoxin-induced effects in farm animal feed.
... DON was the most frequently detected mycotoxin [68.5%] with mean levels of 23.3 g/g creatinine (Waskiewicz et al., 2014). Reproductive disorders have also been observed in various species of experimental animals following exposure to DON via feed Tiemann and Danicke, 2007) A major effect that has been observed at relatively low exposures to DON is its influence on the immune system. This can involve both suppression and stimulation of the immune system leading to hypersensitive conditions (Pestka et al., 2004) . ...
... ZEA is a mycotoxin produced by Fusarium that was shown to induce significant estrogenic effects 62 and reproductive toxicity. 63,64 NIC is an effective antihelminthic drug recommended by the World Health Organization (WHO) 65 and was recently found to be an efficient antitumor and broad-spectrum antiviral agent, 66−68 which could activate estrogen receptor. 69 Along with their wide use, ZEA and NIC have been detected in waters, 70 soils, 71 and even in milk. ...
Since a large number of contaminants are detected in source waters (SWs) and tap waters (TWs), it is important to perform a comprehensive effect evaluation and key contributor identification. A reduced human transcriptome (RHT)-based effect-directed analysis, which consisted of a concentration-dependent RHT to reveal the comprehensive effects and noteworthy pathways and systematic identification of key contributors based on the interactions between compounds and pathway effects, was developed and applied to typical SWs and TWs along the Yangtze River. By RHT, 42% more differentially expressed genes and 33% more pathways were identified in the middle and lower reaches, indicating heavier pollution. Hormone and immune pathways were prioritized based on the detection frequency, sensitivity, and removal efficiency, among which the estrogen receptor pathway was the most noteworthy. Consistent with RHT, estrogenic effects were widespread along the Yangtze River based on in vitro evaluations. Furthermore, 38 of 100 targets, 39 pathway-related suspects, and 16 estrogenic nontargets were systematically identified. Among them, diethylstilbestrol was the dominant contributor, with the estradiol equivalent (EEQ) significantly correlated with EEQwater. In addition, zearalenone and niclosamide explained up to 54% of the EEQwater. The RHT-based EDA method could support the effect evaluation, contributor identification, and risk management of micropolluted waters.
... ZEA wirkt östrogenartig und verursacht Symptome, die dem Komplex des Hyperöstrogenismus zuzuordnen sind [25]. DON hat eine immunsuppressive Wirkung [26]. Als Untersuchungsmaterial diente Galle in Form individueller Proben oder als Poolproben. ...
Zusammenfassung
Gegenstand und Ziel Deoxynivalenol (DON) ist ein Mykotoxin, das von Pilzen der Fusarium spp. gebildet wird. Es verursacht Erbrechen, hat aber auch immunsuppressive Effekte, die sich auch lokal z. B. im Urogenitaltrakt auswirken können und damit fruchtbarkeitsrelevant sind. In diesem Beitrag wird über ein DON-assoziiertes pathomorphologisches Bild des Urogenitaltrakts zusammen mit einer etwaigen mikrobiellen Besiedelung berichtet.
Material und Methode Es wurden 19 Genitaltrakte (Vagina, Zervix, Uterus, Eileiter und Ovarien) inklusive Harnblasen (n = 15) fruchtbarkeitsgestörter Jung- und Altsauen unterschiedlicher Wurfnummern, die in den Jahren 2019/20 aus 8 Betrieben eingesandt wurden, pathomorphologisch untersucht. In 11 individuellen Galle- und 2 Poolproben (2 bzw. 4 Tiere) erfolgte die Bestimmung von DON und Zearalenon (ZEA) mittels Hochleistungsflüssigkeitchromatografie. Zudem unterlagen 17 Uteri und 12 Harnblasen einer mikrobiologischen Untersuchung.
Ergebnisse Fast alle Vaginae (n = 16), Cervices (n = 15), Uteri (n = 18) und viele Eileiter (n = 11) sowie Harnblasen (n = 11) waren überwiegend mittel- bis hochgradig chronisch entzündlich verändert. In 17 Fällen betraf die Entzündung ≥ 2 Organe. In der Regel lag eine Mischflora aus verschiedenen gramnegativen und grampositiven Bakterien vor, wobei E. coli, Streptococcus spp., Aeromonas spp. and Enterococcus spp. dominierten. Insgesamt 8 analysierte individuelle Galleproben und beide Poolproben waren DON-positiv (Konzentrationen 75,5 bis > 200,0 µg/l). In einigen der DON-positiven Proben wurde zeitgleich ZEA in geringen Konzentrationen nachgewiesen (6,57–21,20 µg/l).
Schlussfolgerung und klinische Relevanz Es wird postuliert, dass DON Fruchtbarkeitsprobleme verursachen kann. Zur Abklärung empfehlen sich pathomorphologische Untersuchungen der Genitalorgane und Harnblase. Sind ≥ 2 Organe chronisch entzündlich verändert und besteht zudem eine bakterielle Besiedelung des Uterus, ist eine Beteiligung von DON anzunehmen und durch eine Untersuchung im Gallensaft zu bestätigen.
... The piglets that were exposed during the last week of gestation and during lactation also presented a significant increase in calprotectin serum levels, as well as a decrease of the serum GLP1 when compared to mycotoxin exposure during lactation only. The impact of the interaction of ZEN and DON on the reproductive performance of pigs has previously been described [28,29], whereas their impact on intestinal function and integrity still needs to be elucidated. It has been claimed that ZEN and its derivatives have an anti-inflammatory effect on enterocytes [9,30]. ...
Sows were fed naturally contaminated diets containing: (i) 100 ppb zearalenone (ZEN) one week before farrowing and during the lactation period (at 26 days), (ii) 100 ppb ZEN one week before farrowing and 300 ppb ZEN during the lactation period, or (iii) 300 ppb ZEN one week before farrowing and during the lactation period. All diets contained 250 ppb deoxynivalenol (DON). The highest levels of ZEN, α-ZEL, or β-ZEL were observed in the serum of sows fed 300 ppb ZEN before farrowing and during lactation. However, only α-ZEL was significantly increased in the colostrum and milk of these sows. Sows fed the 300 ppb ZEN during the complete trial presented a significant decrease in backfat thickness before farrowing. This effect was accompanied by a decrease in serum leptin levels. These sows also presented a decrease in estradiol levels and this effect was observed in their piglets exposed during lactation, which presented increased glucagon-like peptide 1, but no changes in serum levels of ZEN, α-ZEL, or β-ZEL. Although all sows were fed the same levels of DON, the serum levels of DON and de-epoxy-DON were increased only in the serum of piglets from the sows fed a diet with the highest ZEN levels during the whole experimental period. Moreover, these piglets presented gut inflammation, as indicated by significantly increased calprotectin levels in their serum.
... Fungi within the genus Fusarium are probably the most prevalent toxin-producing fungi causing contamination of cereal grains grown worldwide [27]. Among the mycotoxins produced by different species of Fusarium, the most representative are DON, ZEA, and FUM, which are toxic to both livestock and humans [28]. ...
Zearalenone (ZEA) is a secondary metabolite with estrogenic effects produced by Fusarium fungi and mainly occurs as a contaminant of grains such as corn and wheat. ZEA, to which weaned gilts are extremely sensitive, is the main Fusarium toxin detected in corn–soybean meal diets. Our aim was to examine the effects of ZEA on the growth performance, intestinal disaccharidase activity, and anti-stress capacity of weaned gilts. Twenty 42-day-old healthy Duroc × Landrace × Large White weaned gilts (12.84 ± 0.26 kg) were randomly divided into control and treatment (diet containing 1.04 mg/kg ZEA) groups. The experiment included a 7-day pre-trial period followed by a 35-day test period, all gilts were euthanized and small intestinal samples were collected and subjected to immunohistochemical and western blot analyses. The results revealed that inclusion of 1.04 mg/kg ZEA in the diet significantly reduced the activities of lactase, sucrase, and maltase in the duodenum, jejunum, and ileum of gilts. Similarly, the activities of superoxide dismutase and glutathione peroxidase in the duodenum, jejunum, and ileum, and activities of catalase in the jejunum and ileum were reduced (p < 0.05). Conversely, the content of malondialdehyde in the duodenum, jejunum, and ileum, and the integrated optical density (IOD), IOD in single villi, and the mRNA and protein expression of heat shock protein 70 (Hsp70) were significantly increased (p < 0.05). The results of immunohistochemical analyses revealed that the positive reaction of Hsp70 in the duodenum, jejunum, and ileum of weaned gilts was enhanced in the ZEA treatment, compared with the control. The findings of this study indicate the inclusion of ZEA (1.04 mg/kg) in the diet of gilts reduced the activity of disaccharidase enzymes and induced oxidative stress in the small intestine, thereby indicating that ZEA would have the effect of reducing nutrient absorption in these animals.
... T-2 toxin is a trichothecene mycotoxin produced by Fusarium acuminatum, Fusarium poae, and Fusarium sporotrichoides [279]. It is known to contaminate wheat, maize, and barley, resulting in feed rejection, growth retardation, and reproductive and gastrointestinal dysfunction in pigs [280]. In chickens, the liver is also a target of T-2 toxin, and its toxicity has been attributed to oxidative stress [281], DNA damage [282], lipid peroxidation [282], apoptosis, and autophagy [283]. ...
Cancer initiation and progression is an accumulation of genetic and epigenetic modifications. DNA methylation is a common epigenetic modification that regulates gene expression, and aberrant DNA methylation patterns are considered a hallmark of cancer. The human diet is a source of micronutrients, bioactive molecules, and mycotoxins that have the ability to alter DNA methylation patterns and are thus a contributing factor for both the prevention and onset of cancer. Micronutrients such as betaine, choline, folate, and methionine serve as cofactors or methyl donors for one-carbon metabolism and other DNA methylation reactions. Dietary bioactive compounds such as curcumin, epigallocatechin-3-gallate, genistein, quercetin, resveratrol, and sulforaphane reactivate essential tumor suppressor genes by reversing aberrant DNA methylation patterns, and therefore, they have shown potential against various cancers. In contrast, fungi-contaminated agricultural foods are a source of potent mycotoxins that induce carcinogenesis. In this review, we summarize the existing literature on dietary micronutrients, bioactive compounds, and food-borne mycotoxins that affect DNA methylation patterns and identify their potential in the onset and treatment of cancer.
... (Adeniran et al., 2013). Penicillium species are known to produce the mycotoxin, Trichothecenes, including DON (Rodrigues and Naehrer, 2012;Tiemann and Dänicke, 2007). However, in this study, we did not screen for the presence of Trichothecenes and other mycotoxins in the feed. ...
... Among the approximately 300 to 400 mycotoxins that have been identified, aflatoxin, fumonisin, ochratoxin, trichothecene (deoxynivalenol, T-2 and HT-2) and ZEN are frequently reported mycotoxins due to safety concerns and economic impact [4,5]. ZEN can interact with estrogen receptors in animals and has been defined as an estrogenic mycotoxin and raised additional attention because of its toxicokinetics, toxicity and estrogenicity [6][7][8]. ...
One of the concerns when using grain ingredients in feed formulation for livestock and poultry diets is mycotoxin contamination. Aflatoxin, fumonisin, ochratoxin, trichothecene (deoxynivalenol, T-2 and HT-2) and zearalenone (ZEN) are mycotoxins that have been frequently reported in animal feed. ZEN, which has raised additional concern due to its estrogenic response in animals, is mainly produced by Fusarium graminearum (F. graminearum), F. culmorum, F. cerealis, F. equiseti, F. crookwellense and F. semitectums, and often co-occurs with deoxynivalenol in grains. The commonly elaborated derivatives of ZEN are α-zearalenol, β-zearalenol, zearalanone, α-zearalanol, and β-zearalanol. Other modified and masked forms of ZEN (including the extractable conjugated and non-extractable bound derivatives of ZEN) have also been quantified. In this review, common dose of ZEN in animal feed was summarized. The absorption rate, distribution ("carry-over"), major metabolites, toxicity and estrogenicity of ZEN related to poultry, swine and ruminants are discussed. Key Contribution: This review summarized data and information from peer-reviewed publications about mycotoxin zearalenone with common contaminated dose in animal feed, toxicokinetics after ingestion, toxicity and estrogenicity in poultry, swine and ruminant animals.
... ZEN is a non-steroidal mycoestrogen, which binds to the 17β-estradiol receptor (ER) in target cells, leading to hyperestrogenism and reproductive disorders in both humans and pigs. Additionally, hemotoxic and genotoxic properties are reported(Tiemann and Dänicke 2007).Aside from ZEN, the modified ZEN forms frequently (co-)contaminate cereal-based foods and feedstuffDe Boevre et al. 2013;Bryła et al. 2018). They are formed by plants and rival fungi by altering the chemical structure mediated by biotransformation reactions, as a natural protective strategy against xenobiotics. ...
... It has also been shown that oral DON administration in mice causes a hepatic inflammatory response and spleen immune dysfunction [39,40]. Different studies have shown different effects of DON on relative organ weight [41,42]. In the current study, the relative liver weight of the DBCU group was obviously decreased compared with that of the DON group, and the relative spleen weight of the DBCU group tended to be higher than that of the DON group. ...
The present study was performed to evaluate the antioxidant and intestinal protective effects of baicalin-copper on deoxynivalenol-challenged piglets. Forty weaned piglets were randomly divided into four groups and assigned to different diets: (1) basal diet (Con), (2) 4 mg/kg deoxynivalenol of basal diet (DON), (3) 5 g/kg baicalin-copper of basal diet (BCU); and (4) 4 mg/kg deoxynivalenol+5 g/kg baicalin‐copper of basal diet (DBCU). The results showed that the ADFI and ADG of piglets in the DON group were markedly lower than those in the Con group, but the ADFI and ADG of the DBCU group were not significantly different from those of the Con group. In piglets fed a DON-contaminated diet, dietary supplementation with BCU significantly decreased the mRNA levels of P70S6K, 4E-BP1, and HSP70 in the liver, the protein expression of HO-1 in the jejunum, and the expression of p-Nrf2 and p-NF-κB in the ileum but increased Mn-SOD activity in serum. Dietary supplementation with BCU increased jejunal maltase, ZIP4 and MT mRNA levels, and serum concentrations of Arg, Val, Ile, Leu, Lys, and Tyr in DON-contaminated piglets. In summary, BCU can alleviate the growth impairment induced by DON and enhance antioxidant capacity and nutrition absorption in piglets fed DON-contaminated diets.
... Trichothecenes A and B are also produced by Fusarium species, and they are present in corn and forages (Tiemann and Danicke, 2007), widely used in TMR analyzed in this survey. These toxins are not very toxic for ruminants (Upadhaya et al., 2010). ...
The objective of this survey was to identify what mycotoxins were present in ingredients used in diets offered to beef cattle in feedlots and their concentrations. The survey covered 30 Brazilian feedlots located in the five major beef-producing states. Samples of total mixed ration (TMR) and ingredients were collected and analyzed for mycotoxin using ultra-performance liquid chromatography coupled to tandem mass spectrometry. Mycotoxin concentrations were further interpreted according to known species-specific sensitivities and normalized according to the principles of toxic equivalent factors (risk equivalent quantities - REQ) expressed in µg kg−1 of aflatoxin B1-equivalent. Forty percent of the visited feedlots had apparent fungi in TMR. However, only one feedlot (3%) used a mycotoxin adsorbent. On the other hand, diets with high contamination presented no apparent fungi. One hundred percent of TMR was contaminated. All samples presented at least one mycotoxin contamination, with 65.5% considered low contamination, 27.6% medium contamination, and 6.90% high contamination. The toxins identified in TMR were fumonisins (most frequently), trichothecenes A, trichothecenes B, fusaric acid, aflatoxins, and ergot (mean concentration values: 2,330, 104.3, 79.5, 105, 10.5, and 5.5 µg kg−1, respectively). According to the contamination of TMR samples per region, Mato Grosso do Sul state presented the highest contaminations. Peanut meal was the most contaminated ingredient. One hundred percent of TMR in Brazilian feedlot is contaminated. Fumonisins were the mycotoxin most frequent and at highest concentrations in TMR samples. Moreover, mycotoxin concentrations have a distinct pattern among ingredients, TMR, and feedlots (local).
... In fact, the ability of DON to elicit vomiting is greater than some of the more potent trichothecenes, such as T-2 toxin [45]. DON and related trichothecenes cause a variety of maladies, including anorexia, feed refusal in livestock, growth retardation, leukocytosis, hemorrhage and adverse effects on reproduction and development [34,[46][47][48][49]. Altered neurochemistry and neuron activity have also been reported as an impact of DON exposure [50]. ...
Trichothecenes are sesquiterpenoid mycotoxins produced by fungi from the order Hypocreales, including members of the Fusarium genus that infect cereal grain crops. Different trichothecene-producing Fusarium species and strains have different trichothecene chemotypes belonging to the Type A and B class. These fungi cause a disease of small grain cereals, called Fusarium head blight, and their toxins contaminate host tissues. As potent inhibitors of eukaryotic protein synthesis, trichothecenes pose a health risk to human and animal consumers of infected cereal grains. In 2009, Foroud and Eudes published a review of trichothecenes in cereal grains for human consumption. As an update to this review, the work herein provides a comprehensive and multi-disciplinary review of the Fusarium trichothecenes covering topics in chemistry and biochemistry, pathogen biology, trichothecene toxicity, molecular mechanisms of resistance or detoxification, genetics of resistance and breeding strategies to reduce their contamination of wheat and barley.
... . T-2 toxin contaminates wheat, maize, barley and animal food, which result in growth retardation and feed rejection (Wahibah et al., 2018), reproductive organ dysfunction (Tiemann and Danicke, 2007), gastrointestinal epithelial barrier dysfunction and vomiting in humans and animals . Chronic toxicity of T-2 toxin causes prostration, ataxia, reduced cardiac output, collapse, shock and death (Babosova et al., 2018). ...
... DON was the most frequently detected mycotoxin [68.5%] with mean levels of 23.3 g/g creatinine (Waskiewicz et al., 2014). Reproductive disorders have also been observed in various species of experimental animals following exposure to DON via feed Tiemann and Danicke, 2007) A major effect that has been observed at relatively low exposures to DON is its influence on the immune system. This can involve both suppression and stimulation of the immune system leading to hypersensitive conditions (Pestka et al., 2004) . ...
Deoxynivalenol (DON) a mycotoxin is frequently found in cereal products consumed throughout the world. Deoxynivalenol is mainly produced by Fusarium graminearum and Fusarium culmorum. The acute symptoms associated with Deoxynivalenol ingestion are vomiting, diarrhoea abnormalities in the kidneys and gastrointestinal tract. In the present work 30 urine samples from the volunteers from different geographical regions of Southern Karnataka were obtained and subjected to the analysis through Liquid Chromatography-Mass spectrometry. Astonishgly Deoxynivalenol was detected at a concentration of 32 to 1065.9ng/mL of human urine sample and 90% of the samples analysed were positive for Deoxynivalenol. Further the urinary creatinine was also analysed which increased with the presence of Deoxynivalenol toxin in the urine samples. A high concentration of creatinine was reported that is 2.89 and 2.79 mg/dL of urine. This is the first survey for Deoxynivalenol in human urine samples from the state of Karnataka population and also the first demonstration of creatinine imbalance with an increase in Deoxynivalenol among Indian population.
... ZEA is a non-steroidal estrogen Fusarium mycotoxin that has strong oestrogenic effects due to its competition with 17-B-estradiol for binding to cytosolic estrogen receptors in the uterus, hypothalamus, mammary gland and pituitary gland (Zhu et al., 2014). ZEA mainly has reproductive toxicity, which can cause reproductive disorders in pigs and cattle such as ovarian atrophy, prolong oestrus cycle, persistent luteal body, false pregnancy and abortion, lower litter size or weak litter size (Tiemann and Danicke, 2007). Previous studies have shown that ZEA induced the apoptosis of granulosa cells (Lai et al., 2015), and ZEA also affected spindle morphology, actin filament expression, epigenetic modifications and cortical granule free domain formation of pig oocytes (Zhu et al., 2014;Han et al., 2015). ...
Zearalenone (ZEA) is an estrogenic mycotoxin produced by Fusarium fungi commonly found in corn, wheat, and other cereals which can infect food and feed commodities, and ZEA mainly has reproductive toxicity which causes widely reproductive disorders in pigs and other animals. However, the toxicity and the functional ways of ZEA on early embryo development is still unclear. In present study we showed that exposure to ZEA (10 μM) significantly decreased the 2-cell and blastocyst developmental rate in porcine early embryos in vitro. ZEA treatment resulted in the occurrence of oxidative stress, showing with increased reactive oxygen species (ROS) level, following with aberrant mitochondrial distribution. Moreover, we found positive signals of γH2A.X in the ZEA-treated embryos, indicating that ZEA induced DNA damage, and the increased autophagy confirmed this. These results suggested that ZEA induced oxidative stress, which further caused mitochondria dysfunction and DNA damage on early embryonic development. We next investigated the effects of melatonin on the ZEA-treated embryo development, and we found that melatonin supplementation could significantly ameliorate ZEA-induced oxidative stress, aberrant mitochondria distribution and DNA damage. In all, our results showed that ZEA was toxic for porcine embryos cultured in vitro and melatonin supplementation could protect their development from the effects of ZEA.
... Additionally, hemotoxic and genotoxic properties are reported. 4 Aside from ZEN, modified-ZEN forms frequently cocontaminate cereal-based foods and feedstuff. 5−7 They are formed by plants and rival fungi by altering the chemical structure via biotransformation reactions as a natural protective strategy against xenobiotics. ...
The aim of this study was to determine the toxicokinetic characteristics of ZEN and its modified forms, α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), zearalenone-14-glucoside (ZEN14G) and zearalenone-14-sulfate (ZEN14S), including (pre)systemic hydrolysis in pigs. Cross-over pig trials were performed by means of intravenous and oral administration of ZEN and its modified forms. Systemic plasma concentrations of the administered toxins and their metabolites were quantified and further processed via tailor-made compartmental toxicokinetic models. Furthermore, portal plasma was analysed to unravel the site of hydrolysis, and urine samples were analysed to determine urinary excretion. Results demonstrate ZEN14G and ZEN14S to be (completely) presystemically hydrolysed to ZEN and demonstrate high oral bioavailability for all administered compounds, with further extensive first pass glucuronidation. Conclusively, the modified ZEN forms α-ZEL, β-ZEL, ZEN14G and ZEN14S contribute to overall ZEN systemic toxicity in pigs and should be taken in account for the risk assessment.
... Zearalenone (ZEA), a nonsteroidal estrogenic mycotoxin from Fusarium fungi, causes reproductive toxicity in farm animals (Fushimi et al., 2015;Minervini and Dell'Aquila, 2008;Tiemann and Danicke, 2007;Yang et al., 2007). Since the structure of ZEA resembles that of 17β-estradiol, ZEA binds to estrogen receptors to exhibit estrogen functions (Adibnia et al., 2016;Gajecka et al., 2013;Minervini et al., 2001;Turcotte et al., 2005). ...
Mycotoxins are a heterogeneous group of toxins produced by fungi that can grow in staple crops (e.g., maize, cereals), resulting in health risks due to widespread exposure from human consumption and inhalation. Dried blood spot (DBS), dried serum spot (DSS), and volumetric tip microsampling (VTS) assays were developed and validated for several important mycotoxins. This review summarizes studies that have developed these assays to monitor mycotoxin exposures in human biological samples and highlights future directions to facilitate minimally invasive sampling techniques as global public health tools. A systematic search of PubMed (MEDLINE), Embase (Elsevier), and CINAHL (EBSCO) was conducted. Key assay performance metrics were extracted to provide a critical review of the available methods. This search identified 11 published reports related to measuring mycotoxins (ochratoxins, aflatoxins, and fumonisins) using DBS/DSS and VTS assays. Multimycotoxin assays adapted for DBS/DSS and VTS have undergone sufficient laboratory validation for applications in large-scale population health and human biomonitoring studies. Future work should expand the number of mycotoxins that can be measured in multimycotoxin assays, continue to improve multimycotoxin assay sensitivities of several biomarkers with low detection rates, and validate multimycotoxin assays across diverse populations with varying exposure levels. Validated low-cost and ultrasensitive minimally invasive sampling methods should be deployed in human biomonitoring and public health surveillance studies to guide policy interventions to reduce inequities in global mycotoxin exposures.
Zearalenone (ZEA) is an estrogen-like mycotoxin characterized mainly by reproductive toxicity, to which pigs are particularly sensitive. The aim of this study was to investigate the molecular mechanism of ZEA-induced apoptosis in porcine endometrial stromal cells (ESCs) by activating the JNK signaling pathway through endoplasmic reticulum stress (ERS). In this study, ESCs were exposed to ZEA, with the ERS inhibitor sodium 4-Phenylbutyrate (4-PBA) as a reference. The results showed that ZEA could damage cell structures, induce endoplasmic reticulum swelling and fragmentation, and decreased the ratio of live cells to dead cells significantly. In addition, ZEA could increase reactive oxygen species and Ca2+ levels; upregulate the expression of GRP78, CHOP, PERK, ASK1 and JNK; activate JNK phosphorylation and its high expression in the nucleus; upregulate the expression Caspase 3 and Caspase 9; and increase the Bax/Bcl-2 ratio, resulting in increased apoptosis. After 3 h of 4-PBA-pretreatment, ZEA was added for mixed culture, which showed that the inhibition of ERS could reduce the cytotoxicity of ZEA toward ESCs. Compared with the ZEA group, ERS inhibition increased cell viability; downregulated the expression of GRP78, CHOP, PERK, ASK1 and JNK; and decreased the nuclear level of p-JNK. The Bax/Bcl-2 ratio and the expression of Caspase 3 and Caspase 9 were downregulated, significantly alleviating apoptosis. These results demonstrate that ZEA can alter the morphology of ESCs, destroy their ultrastructure, and activate the JNK signaling via the ERS pathway, leading to apoptosis.
Zearalenone (ZEN) and deoxynivalenol (DON) are mycotoxins produced by various species of Fusarium fungi. They contaminate agricultural products and negatively influence human and animal health, thus representing a serious problem of the agricultural industry. Earlier we showed that compactin, a secondary metabolite of Penicillium citrinum, is able to completely suppress the aflatoxin B1 biosynthesis by Aspergillus flavus. Using the F. culmorum strain FC-19 able to produce DON and ZEN, we demonstrated that compactin also significantly suppressed both DON (99.3%) and ZEN (100%) biosynthesis. The possible mechanisms of this suppression were elucidated by qPCR-based analysis of expression levels of 48 biosynthetic and regulatory genes. Expression of eight of 13 TRI genes, including TRI4, TRI5, and TRI101, was completely suppressed. A significant down-regulation was revealed for the TRI10, TRI9, and TRI14 genes. TRI15 was the only up-regulated gene from the TRI cluster. In the case of the ZEN cluster, almost complete suppression was observed for PKS4, PKS13, and ZEB1 genes, and the balance between two ZEB2 isoforms was altered. Among regulatory genes, an increased expression of GPA1 and GPA2 genes encoding α- and β-subunits of a G-protein was shown, whereas eight genes were down-regulated. The obtained results suggest that the main pathway for a compactin-related inhibition of the DON and ZEN biosynthesis affects the transcription of genes involved in the G-protein-cAMP-PKA signaling pathway. The revealed gene expression data may provide a better understanding of genetic mechanisms underlying mycotoxin production and its regulation.
As gallic acid (GA) role in zearalenone (ZEN); mediated reproductive dysfunction has not been studied, we report on GA's effect on reproductive dysfunction in rats treated with ZEN‐100 µg/kg alone, or with GA‐40 mg/kg; for 4 weeks. The mycotoxin ZEN contaminates crops, causing toxicity on ingestion, economic losses, and alters reproductive function. Relative to control, GA reversed ZEN‐induced reduction of rats' testicular function enzymes and reproductive hormones and improved ZEN‐impaired sperm quality. GA significantly (p < 0.05) increased rats antioxidant status, inhibited (p < 0.05) reactive oxygen and nitrogen species and lipid peroxidation levels, and abated (p < 0.05) proinflammatory biomarkers in the examined organs: hypothalamus, testis, and epididymis. Histopathology revealed that GA facilitated the preservation of testicular and epididymal cytoarchitecture significantly altered in rat cohorts treated with ZEN alone. Conclusively, GA protected against ZEN‐induced toxicity in the rats' organs examined, enhanced endogenous antioxidative protective mechanism, and abated proinflammatory responses. GA further averted a decline in circulatory, reproductive enzymes, hormone levels. GA also protected against reproductive tissue damage and improved parameters of sperm functionality.
Zearalenone (ZEN) is one of the secondary metabolites of Fusarium and is regarded as a common contaminant of foodstuffs especially corn products. ZEN is considered to be cytotoxic, tissue toxic, genotoxic and reproductive toxic, which acts as a serious threat for humans and animals. In this study, we investigated the effects of ZEN on organelle function during porcine oocyte meiotic maturation. Our results showed that the expansion of cumulus granulosa cells and the extrusion of oocyte polar body were disturbed after ZEN exposure. Besides the aberrant mitochondrial distribution and impaired mitochondrial membrane potential after ZEN treatment during porcine oocyte maturation. We also found the fluorescence intensity of ER was decreased, and ZEN exposure altered ER stress level, showing with the reduced expression of GRP78. We also found that the spindle cortex distribution of Golgi apparatus was disrupted in ZEN-exposed oocytes, which was confirmed by the decreased level of GM130, moreover, our data also showed that Rab11-based vesical transport was disturbed, indicating the Golgi apparatus function was disrupted. Besides, the fluorescence intensity of lysosome was significantly increased, indicating the protein degradation and the potential autophagy occurrence after ZEN treatment. Thus, our results demonstrated that exposure to ZEN affected porcine oocyte meiotic maturation through its wide effects on organelle function for protein synthesis, transport and degradation.
Zearalenone (ZEA) is a harmful secondary fungal metabolite, produced primarily by plant pathogenic fungi mostly belonging to the genus Fusarium. It is involved in reproductive disorders in animals since its structure is similar to the estrogen hormone. This induces precocious pubertal changes, fertility problems, and hyper estrogenic disorders. The main objectives of this study were to evaluate the ZEA removal capacity of plant-derived lactic acid bacteria (LAB) and to investigate the possible components and mechanisms involved in the removal of ZEA by physically and chemically treated plant-derived LAB. The bacterial cells were characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and the analysis of zeta potential, and hydrophobic index. Results revealed that 17 out of 33 plant-derived LAB exhibited ZEA removal from liquid medium. The percentage of removal ranged from 0.5–23% and Lactobacillus plantarum BCC 47723, isolated from wild spider flower pickle (Pag-sian-dorng), exhibited the highest removal. The alteration of proteins on L. plantarum BCC 47723 structure by Sodium dodecyl sulphate (SDS) treatment was positively affected on ZEA removal, whereas that of lipids on ZEA removal was negatively observed. Heat treatment influenced the higher ZEA adsorption. SEM images showed that the morphologies of modified bacterial cells were distinctly deformed and damaged when compared with untreated control. FTIR analysis indicated that the original functional groups, which included amide (C=O, C-N), carboxyl (C=O, C-O, O-H), methylene (C=C), and alcohol (O-H) groups, were not changed after ZEA adsorption. The zeta potential indicated that electrostatic interaction was not involved in the ZEA removal, while hydrophobicity was the main force to interact with ZEA. These findings can conclude that adsorption by hydrophobicity is the main mechanism for ZEA removal of plant-derived L. plantarum BCC 47723. The alteration of bacterial cell structure by heat treatment enhanced the efficiency of L. plantarum BCC 47723 for ZEA reduction. Its activity can be protected by the freeze-drying technique. Hence, plant-derived L. plantarum BCC 47723 can be considered as an organic adsorbent for ZEA reduction in food and feedstuff.
Seed is the basic unit of crop production and has greater contribution to environmental and cultural factors and is widely distributed in national and international trade. The seeds are found to be responsible for disease transmission because they carry a number of pathogens. The toxigenic fungal flora, existing in conjunction with food, largely includes genera Aspergillus, Fusarium, and Penicillium and, to a lesser extent, the genera Alternaria, Claviceps, and Stachybotrys. These economically important species of fungi produce significant mycotoxins. More than 400 mycotoxins are known to exist in nature. Contamination of foods and feeds with mycotoxins is a worldwide serious problem. The most important mycotoxins in terms of toxic effect on both humans and animals are aflatoxins (AFs), citrinin (CIT), cyclopiazonic acid (CPA), fumonisins (FBs), moniliformin (MON), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T-2), patulin (PAT), zearalenone (ZEA), and ustiloxins. These mycotoxins have several adverse impacts on consumers, such as loss of human and animal lives, health-care and veterinary care costs, contaminated food and feed disposal costs, and huge investment in research and management of the mycotoxin problem. The mycotoxins induce diverse biological effects, which have been characterized on animals and humans. These toxic effects of mycotoxins include cytotoxic, carcinogenic, immune suppressive, nephrotoxic neurotoxic, mutagenic and estrogenic effects, etc.
Objective:
Deoxynivalenol (DON) and zearalenone (ZEN) are mycotoxins that frequently contaminate maize and grain cereals, imposing risks to the health of both humans and animals and leading to economic losses. The gut microbiome has been shown to help combat the effects of such toxins, with certain microorganisms reported to contribute significantly to the detoxification process.
Methods:
We examined the cecum contents of three different dietary groups of pigs (control, as well as diets contaminated with 8 mg DON/kg feed or 0.8 mg ZEN/kg feed). Bacterial 16S rRNA gene amplicons were acquired from the cecum contents and evaluated by next-generation sequencing.
Results:
A total of 2,539,288 sequences were generated with ~500 nucleotide read lengths. Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla, occupying more than 96% of all three groups. Lactobacillus, Bacteroides, Megasphaera, and Campylobacter showed potential as biomarkers for each group. Particularly, Lactobacillus and Bacteroides were more abundant in the DON and ZEN groups than in the control. Additionally, 52,414 operational taxonomic units (OTUs) were detected in the three groups; those of Bacteroides, Lactobacillus, Campylobacter, and Prevotella were most dominant and significantly varied between groups. Hence, contamination of feed by DON and ZEN affected the cecum microbiota, while Lactobacillus and Bacteroides were highly abundant and positively influenced the host physiology.
Conclusion:
Thus, Lactobacillus and Bacteroides play key roles in the process of detoxification and improving the immune response. We, therefore, believe that these results may be useful for determining whether disturbances in the intestinal microflora, such as the toxic effects of DON and ZEN, can be treated by modulating the intestinal bacterial flora.
Zearalenone is a phenolic Fusarium mycotoxin, which is ubiquitous in human and animal feedstuff and often co-occurs with other mycotoxins. ZEA has been reported to disturb Leydig cell function and even cause the apoptosis to the Leydig cells. However, the effects of gestational exposure to zearalenone on fetal Leydig cells and the underlying mechanism remain unknown. Sprague Dawley dams were daily gavaged with 0, 2.5, 5, 10, and 20 mg/kg body weight ZEA from gestational day 14–21. On gestational day 21, rats were euthanized and serum testosterone levels were measured, and testes were collected for further evaluation of Leydig cell number, cell size, gene, and protein expression. Zearalenone significantly decreased anogenital distance and its index of male fetus, serum testosterone levels, Leydig cell proteins (SCARB1, STAR, CYP11A1, CYP17A1, and INSL3), and fetal Leydig cell number at 10 and/or 20 mg/kg by delaying the commitment of stem Leydig cells into the Leydig cell lineage and proliferation. Further study found that Notch signaling (RFNG, PSEN1, NOTCH1, and NOTCH3) was up-regulated by zearalenone. In conclusion, gestational exposure to high doses of zearalenone (10 and 20 mg/kg) blocks fetal Leydig cell development, thus possibly causing the anomalies of the male reproductive tract.
Zearalenone (ZEA) is a prevalent non-steroidal estrogenic mycotoxin produced mainly by Fusarium contamination. Our previous study showed that ZEA induces the autophagy of Sertoli cells (SCs). However, the underlying mechanisms are still unknown. Several studies have indicated that the increasing level of cytoplasmic Ca2+ could induce autophagy through CaMKKβ and AMPK pathways. Thus in order to investigate the potential mechanism underlying ZEA-induced autophagy, the activity of calmodulin-dependent kinase kinase β(CaMKKβ)and AMP-activated protein kinase (AMPK) signaling pathway in ZEA-infected TM4 cells was studied. In the present study, ZEA activated the CaMKKβ and AMPK signaling pathways. The AMPK inhibitor and activator significantly inhibited and stimulated the effect of ZEA on AMPK, the transformation from LC3I to LC3II, and the distribution of LC3 dots. In addition, cytosolic calcium (Ca2+) was increased gradually with the concentration of ZEA. After treatment of ZEA-infected cells with 1, 2-bis (2-aminophenoxy) ethane-N, N, N', N'- tetraacetic acid- tetraac etoxymethyl ester (BAPTA-AM) and 2-aminoethyl diphenylborinate (2-APB), the intracellular concentration of Ca2+ reduced significantly. Also, the activities of CaMKKβ and AMPK and subsequent autophagy decreased. Moreover, the antioxidant NAC significantly decreased activities of AMPK and autophagy -related protein. Therefore, it can be speculated that ROS- mediated ER-stress induced by ZEA activates AMPK via Ca2+-CaMKKβ leading to autophagy in TM4 cells.
In dreijährigen Fruchtfolgeversuchen an zwei Standorten nördlich von Göttingen wurde der Einfluss der Vorfrüchte Mais, Zuckerrübe und Weizen auf den Ährenbefall, die Mykotoxinbelastung und die Zusammensetzung der Fusariumpopulation an Ähren in der Folgefrucht Winterweizen untersucht. In den Versuchsjahren 2007, 2008 und 2009 traten witterungsbedingt unterschiedliche Bedingungen für Fusarium-Ähreninfektionen in Weizen auf. Beim Vergleich der gewichteten Faktoreffekte zeigte sich die dominierende Bedeutung der Witterung auf den Mykotoxingehalt in den Körnern. Die Deoxynivalenolgehalte auf beiden Standorten unterschieden sich signifikant, die relativen Standorteffekte waren unabhängig von den Versuchsjahren. Im Gegensatz dazu variierten die Faktoreffekte der drei Vorfruchtvarianten Mais, Winterweizen und Zuckerrübe zwischen den Befallsjahren. In einem durchschnittlichen Befallsjahr wie 2009 war eine Differenzierung zwischen allen drei Vorfruchtvarianten möglich. In einem Starkbefallsjahr wie 2007 unterschieden sich die Getreideproben aus den Vorfruchtvarianten Zuckerrübe und Winterweizen hinsichtlich ihres Mykotoxingehaltes jedoch nicht signifikant, eine Differenzierung war nur zu den Proben der Vorfruchtvariante Mais möglich. Die Zusammensetzung der Pilzpopulation an den Ähren zeigte, dass Fusarium graminearum unabhängig von der Vorfrucht und dem Jahreseffekt als Leitpathogen auftrat. Aus den vorliegenden Untersuchungen kann gefolgert werden, dass die relative Vorfruchtwirkung von Zuckerrübe und Weizen auf den Mykotoxingehalt in der Folgefrucht Winterweizen von der saisonalen Jahreswitterung und dem daraus resultierenden Befallsdruck mit Ährenfusarium abhängig ist. Die Ursachen, die in Risikojahren zu unerwartet erhöhten Mykotoxingrenzwerten auch nach Zuckerrüben führen können, müssen im Einzelnen noch aufgeklärt werden.
Zearalenone (ZEA) is a mycotoxin produced by the fungi of Fusarium genera, which contaminates the cereals and food stuffs worldwide. Fusarium mycotoxins are considered as important metabolites related to animal and human health. Evidences indicate that ZEA has been found to be present in different food stuffs from developed countries like USA, Canada, France, Germany, Japan, etc. and developing nations like Egypt, Thailand, Iran, Croatia, Philippines, etc. The toxicokinetic studies reveal that following oral exposure of ZEA, the compound is absorbed through gastrointestinal tract (GIT), gets metabolized and distributed to different body parts. ZEA has been shown to cause reproductive disorders in laboratory animals. Although the toxicity of ZEA in humans have not been conclusively established nonetheless, limited evidences indicate that ZEA can cause hyper estrogenic syndrome. Though, ZEA causes low acute toxicity, but reports are available confirming the systemic toxicity caused by ZEA. There is no review available that addresses the occurrence, systemic toxicity and the probable mechanisms of ZEA toxicity. This review shall address the world-wide occurrence and in vivo & in vitro toxicity studies of ZEA over the past 20 years. The review shall also discuss the toxicokinetics of ZEA and metabolites; illustrates the systemic toxicity and probable mechanisms of action leading to the risk associated with ZEA.
Primary ovarian diseases are rather uncommon in swine. The vast majority of ovarian disorders are secondary to risk factors related to management or environment. Uterine diseases, particularly inflammation, typically present for diagnosis based on clinical signs such as pathological vulvar discharge. The diagnostic procedure addressing herd fertility problems is comprehensive and must include a critical assessment of the tripartite contributors to herd reproductive performance: farrowing personnel, breeding personnel, and sow and semen management. Diagnosticians must be aware of the multitude of factors and their interrelatedness that might be causative of the problem, including facility type, the building environment, seasonality, nutrition, sanitation/hygiene, and disease‐related occurrences or interventions. When initiating a herd reproductive investigation, a first step is to assess production records, paying particular attention to the ratio of regular versus irregular returns (suggested target 4 : 1) to obtain initial insight as to whether the causes are likely infectious or noninfectious.
HT-2 toxin is one of the type A trichothecene mycotoxins existed in contaminated feed and has exerted various toxic effects on human and livestock, as it induces lesions in multiple tissues including reproductive system. However, till now it is still unclear about the toxicity of HT-2 on mammalian embryos. In this study, we showed that HT-2 treatment disrupted mouse early embryo development, and we also found the occurrence of oxidative stress, showing with the increased ROS level. This might be due to the mitochondria dysfunction, since the occurrence of aberrant mitochondria distribution was observed. Moreover, HT-2 exposure caused DNA damage, showing with the positive signal of γH2 A.X; and HT-2 treatment embryos showed increased LC3 positive signals, indicating the induction of autophagy, which further confirmed the occurrence of DNA damage. Thus, our results showed that HT-2 exposure impaired mouse embryo development by inducing oxidative stress, mitochondria dysfunction and DNA damage.
The main arguments, discussed by different international organizations, which confirm the significance
of problems connected with the presence of zearalenone in animal feed materials and their influence on the
safety of food materials are shown in this review article. The main world research trends focused on
zearalenone, as undesirable substances, are also presented. A variety of Fusarium fungi produce a number of
different mycotoxins, for example zearalenone. Is not true that Fusarium fungi are they the most prevalent
toxin-producing fungi only in the northern temperate regions, are also commonly found on cereals grown in
the temperate regions of America, Europe and Asia. Zearalenone have been shown to cause a variety of
toxic effects in both experimental animals and livestock, and have also been suspected of causing toxicity in
humans. Zearalenone is a stable compound, both during storage/milling and the processing/cooking of food,
and it does not degrade at high temperatures. Studies of metabolism indicate that zearalenone is fairly
rapidly absorbed following oral administration, with the formation of a- and b-zearalenol and a- and
a-zearalanol, which are subsequently conjugated with glucuronic acid. This mycotoxin and some of these
metabolites have been shown to competitively bind to estrogen receptors in a number of in vitro systems.
Binding to specific receptors has been demonstrated in the uterus, mammary gland, liver and hypothalamus
of different species. Additionaly alterations of immunological parameters were found at high zearalenone
concentrations in vitro. Zearalenone causes alterations in the reproductive tract of laboratory animals and
domestic animals. Various estrogenic effects such as decreased fertility, increased embryolethal resorptions,
reduced litter size, changed weight of adrenal, thyroid and pituitary glands and change in serum levels of
progesterone and estradiol have been observed, and teratogenic effects were found in pigs and sheep. It may
be that the safety of zearalenone could be evaluated on the basis of the dose which had no hormonal effects
in pigs, the most sensitive species, and a temporary Tolerable Daily Intake for zearalenone of 0.2 mg/kg of
body weight, could be established.
Molds are parasitic plants that are ubiquitous in livestock feedstuffs. Even though molds themselves reduce the quality of grains, their synthesis of chemical substances termed mycotoxins causes the greatest monetary loss to the animal industry. Five major mycotoxins that impair growth and reproductive efficiency in North America are aflatoxins, zearalenone, deoxynivalenol, ochratoxin, and ergot. Aflatoxins are produced by Aspergillus flavus and Aspergillus parasiticus. Consumption of grains containing aflatoxins by swine affects reproduction indirectly by reducing feed intake and growth. In swine, aflatoxins impair liver and kidney function, delay blood clotting, increase susceptibility to bruising, and interfere with cellular humoral immune systems. Ruminants are comparatively resistant to aflatoxicosis, but presence of aflatoxins in milk of dairy cows is closely monitored for human safety. Depending on environmental conditions, Fusarium roseum can produce either zearalenone or deoxynivalenol. Days 7 to 10 postmating seem to be a critical period of gestation for zearalenone to exert its detrimental actions on early embryonic development. Presence of deoxynivalenol in swine feedstuffs decreases feed intake, causes feed refusal, and induces occasional vomiting. Several species of Penicillium and Aspergillus produce ochratoxin, a mycotoxin that causes necrosis of kidney tissue. Ergot alkaloids produced by Claviceps purpurea on wheat can cause reproductive problems and are associated with lactational failure in swine. Various methods have been developed to remove mycotoxins from infected feedstuffs. Chemical analyses in laboratories as well as diagnostic kits suitable for use at the elevator or farm can be used successfully to identify which mycotoxins are present in suspect feedstuffs.
First litter sows in naturally occurring post-weaning estrus were hand mated to proven boars and were fed a diet supplemented with zearalenone, an estrogenic mycotoxin (1 mg zearalenone/kg body weight), or a control diet on days 7 through 10 after mating. Embryos (blastocysts) and endometrial biopsies were collected from control and treated sows on days 9, 11, and 13 after mating. All blastocysts harvested on day 9 were spherical; treatment of sows with zearalenone had no effect on blastocyst development. Blastocysts collected from treated sows on day 11 were in stages of elongation comparable to those of blastocysts from control sows but had mild degenerative changes in the embryonic disks, characterized by slightly retarded development and an increase in the number of necrotic cells. Blastocysts collected from treated sows on day 13 were in an advanced stage of degeneration, characterized by circumferential constrictive division, fragmentation, and degeneration and disorganization of the embryonic disk. Feeding zearalenone to pregnant sows had no effect on the normal decrease in height of the endometrial luminal epithelium on days 9 through 13 after mating and no effect on morphologic appearance of secretory vesicles in the endometrial glandular epithelium. The dosage scheme of zearalenone used in this study did not cause any morphologic changes in the endometrium that could be associated with hyperestrogenism.
To assess the potential for mycotoxin contamination of the human food supply following the 1988 U.S. drought, 92 grain food samples were purchased from retail outlets in the summer of 1989 and surveyed for aflatoxin B1, zearalenone, and deoxynivalenol (DON [vomitoxin]) by monoclonal antibody-based competitive enzyme-linked immunosorbent assay (ELISA). Only one sample (buckwheat flour) was found to contain aflatoxin B1 (12 ng/g), whereas zearalenone was found in 26% of the samples at a mean concentration of 19 ng/g. In contrast, the DON ELISA was positive in 50% of the samples at a detection level of 1.0 micrograms/g. Between 63 and 88% of corn cereals, wheat flour/muffin mixes, rice cereals, and corn meal/muffin mixes yielded positive results for DON, whereas 25 to 50% of oat cereals, wheat- and oat-based cookies/crackers, corn chips, popcorn, and mixed-grain cereals were positive for DON. The mean DON content of the positive samples was 4.0 micrograms/g, and the minimum and maximum levels were 1.2 and 19 micrograms/g, respectively. When positive ELISA samples were also analyzed by high-performance liquid chromatography, a strong correlation between the two methods was found. The presence of DON in the two highest samples, corn meal and mixed-grain cereal, which contained 19 and 16 micrograms/g, respectively, was quantitatively confirmed by gas chromatography-mass spectrometry. The results indicated that DON was present in 1989 retail food products at concentrations that exceeded those found in previous market surveys and that have been experimentally associated with impaired animal health.
The liquid chromatographic (LC) method described, suitable for use with both blood plasma and urine, is applicable for determination of zearalenone and alpha-zearalenol at levels as low as 0.5 ng/mL plasma and 5 ng/mL urine. The sample is incubated overnight with beta-glucuronidase to analyze for both conjugated and unconjugated forms of zearalenone. The next day, the sample is acidified with H3PO4, extracted with chloroform, and evaporated to dryness. The residue is dissolved in toluene and loaded onto a silica gel cartridge which is washed with toluene and eluted with toluene-acetone (88 + 12). The eluate is evaporated, and the residue is dissolved in chloroform, extracted with 0.18M NaOH, neutralized with H3PO4, and re-extracted with chloroform. The chloroform extract is evaporated, dissolved in mobile phase for LC, and injected onto a normal phase column under the following chromatographic conditions: mobile phase of water-saturated dichloromethane containing 2% 1-propanol, and fluorescence detector, excitation wave-length 236 nm, and 418 nm cut-off emission filter. Recoveries of zearalenone and its metabolites from blood plasma and urine are 80-89% in the range 2.0-10 ng standard/mL plasma, and 81-90% in the range 10-30 ng standard/mL urine. This method was used to analyze blood and urine samples from a pig fed zearalenone-contaminated feed (5 mg/kg), corresponding to 80 micrograms/kg body weight. Zearalenone was rapidly metabolized to alpha-zearalenol, which appeared in the blood only 30 min after feeding. Almost all zearalenone and alpha-zearalenol was found conjugated with glucuronic acid in both blood plasma and urine.
Purified zearalenone (Z) was added to the diet of gilts from d 2 to 15 postmating. Gilts received either 0, 5, 15, 30, 60 or 90 ppm Z (three to five gilts per dose) in 1.8 kg of feed daily. Serum concentrations of progesterone and estradiol-17 beta were determined weekly. On d 13 to 15 and 40 to 43 postmating, blood samples were drawn from a cannula at 20 min intervals for 4 h and analyzed for luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL). Gilts were killed 40 to 43 d postmating and embryonic development was assessed. Treatment with 5, 15 or 30 ppm Z had no effect on embryonic development when compared with 0 ppm. No fetuses were present in gilts fed 60 to 90 ppm Z, but two gilts given 60 ppm Z had remnants of fetal membranes in the uterus. The histologic appearance of reproductive tract tissues from the gilts given 60 ppm Z was similar to that from pregnant gilts. Tissues from gilts given 90 ppm Z appeared to be stimulated by both estrogen and progesterone. Serum concentrations of progesterone were decreased at 2, 3 and 6 wk postbreeding in gilts fed 60 and 90 ppm Z. Serum concentrations of estradiol-estradiol-17 beta were decreased at 4 wk postbreeding in gilts fed 60 and 90 ppm Z.(ABSTRACT TRUNCATED AT 250 WORDS)
While approximately 60 000 chemicals are in widespread use with 1000 new chemicals introduced into the environment each year, the biologic effects of these agents are poorly understood. With the specific goal of testing for potential reproductive toxicity, we have established methodology for the screening of compounds in vitro by measuring effects on progesterone production by porcine granulosa cells in culture. Granulosa cells were harvested by mechanical agitation, cryopreserved, and cells with known progesterone production capacity utilized for culture. Agents to be tested were added to cultures of 10(5) cells and the media assayed for progesterone by radioimmunoassay. Estradiol suppression of progesterone production was easily demonstrated in this system and utilized as a verification of responsiveness. The pesticide o,p-DDT and its isomer p,p-DDT produced dramatic suppression of progesterone production apparently with equal potencies to estradiol. By contrast, the pesticides malathion, parathion and dieldrin and the fungicide hexachlorobenzene were without effect in this test system.
Similarities in structure and function between pigs and human beings include size, feeding patterns, digestive physiology, dietary habits, kidney structure and function, pulmo nary vascular bed structure, coronary artery distribution, propensity to obesity, respiratory rates, tidal volumes and social behaviors. Since the pig is an omnivore, it provides an adaptable model to evaluate chronic and acute exposures to xenobiotics such as alcohoL caffeine, tobacco, food additives and environmental pollutants. Swine have been used successfully as models to evaluate alcoholism, diabetes, absorption, digestion, total paren teral nutrition, organ transplantation, atherosclerosis, exercise, hypertension. hemorrhagic hypotension, melanoma, gingivitis, obstructive and reflux nephropathy. osteochondrosis. dermal healing and septic shock. A severe and worsening shortage of organs and tissues for transplantation in patients with severe organ failure has encouraged the consideration of inter species or xenotransplan tation. In developing programs toward this end, the pig generally is viewed as the preferred donor because of its size, physiology and availability. The pig harbors relatively few diseases which could be transmitted inadvertently to human patients. The ability to genetically modify swine to ameliorate the consequences of the human immune response offers a further significant advantage. Another important consideration for an animal model is that basic biologic back ground information be available for investigators to design future prospective studies.
This chapter discusses metabolism of zearalenone in farm animals. The subcellular distribution of the hepatic zearalenone-reducing activity in various female domestic animals has been investigated by incubating liver homogenate and its subcellular fractions with zearalenone and coenzymes (NADH or NADPH) + regenerating systems. The zearalenone-reducing activity was found to be distributed mainly to the microsomal and cytosol fraction. The distribution of the activities differed among female domestic species. In the pig, both α- and β-zearalenol formation were located mainly in the microsomal fraction, independently of coenzyme requirement. Cow and hen had the NADH- and NADPH-dependent α-zearalenol formation located in the microsomal fraction, but differed sharply from pig as regards the formation of β-zearalenol. With NADH as coenzyme, cow and hen did not form any detectable amounts of β-zearalenol and with NADPH the formation occurred only in the cytosol fraction. The distribution patterns of α- and β-zearalenol formation in the goat were similar to that found in the pig. Sheep differed from pig and goat as regards to the distribution of NADPH-dependent α-zearalenol formation, which was located mostly in the cytosol fraction.
Control wheat and wheat artificially inoculated with Fusarium culmorum and as well as wheat contaminated mainly with deoxynivalenol (DON) were gradually blended to yield diets for pigs with increasing DON concentrations (0.2, 0.7, 1.2, 2.5, 3.7 mg/kg) at a total wheat content of 400 g/ kg diet. Performance was recorded over a liveweight range between 34 and 104 kg (n=18 per group). Blood was drawn from the jugular vein after five weeks on the experimental diets to determine the clinical-chemical parameters and DON concentrations. In addition, a balance study was carried out with the groups fed the diets with the lowest and the highest DON concentration to test the effects on nutrient digestibility and DON metabolism. DON and its metabolite de-epoxy-DON were analysed in physiological samples by HPLC after cleanup by immuno-affinity columns (IAC). Performance of pigs was not significantly affected by increasing dietary DON concentrations, although there was a trend toward a decrease in weight. This was especially true for the group fed the diet with 3.7 mg DON/kg, which consumed 5% less feed and gained 8% less liveweight than the control group. Serum clinical-chemical parameters, such as albumin, total protein, GLDH, ASAT, γ-GT and immunoglobulins were not influenced by the dietary treatments. DON concentration in serum increased in a dose-response-related manner and did clearly reflect the DON exposure of the animals. However, adverse effects on performance were only obvious for the group fed the diet with the highest DON concentration. No significant differences were found for nutrient digestibility of the tested diets. With regard to the DON balance and metabolism, urine was the main excretory route. A total of 52.3% of the ingested DON was eliminated as the parent toxin whereas 2.6% was excreted as the metabolite de-epoxy-DON in the group fed the diet with 3.7 mg DON/kg. The excretion of both substances accounted for approximately 98% of the total DON recovery from urine and faeces, which indicates the important role of the urinary elimination route. De-epoxy-DON accounted for approximately 5% of the urinary excretion of de-epoxy-DON plus DON, whereas in faeces a ratio of approximately 97% was found, which underlines the role of the digestive tract in the metabolism of DON in the pig.
Influence of Low-Level Exposure to Fusarium Mycotoxins on Selected Immunological and Hematological Parameters in Young Swine. Rotter, B. A., Thompson, B. K., Lessard, M., Trenholm, N. L., and Trypbonas, H. (1994). Fundam. Appl. Toxicol. 23, 117-124.
Trichothecene mycotoxins are a group of structurally similar fungal metabolites that are capable of producing a wide range of toxic effects. Deoxynivalenol (DON, vomitoxin), a trichothecene, is prevalent worldwide in crops used for food and feed production, including in Canada and the United States. Although DON is one of the least acutely toxic trichothecenes, it should be treated as an important food safety issue because it is a very common contaminant of grain. This review focuses on the ability of DON to induce toxicologic and immunotoxic effects in a variety of cell systems and animal species. At the cellular level, the main toxic effect is inhibition of protein synthesis via binding to the ribosome. In animals, moderate to low ingestion of toxin can cause a number of as yet poorly defined effects associated with reduced performance and immune function. The main overt effect at low dietary concentrations appears to be a reduction in food consumption (anorexia), while higher doses induce vomiting (emesis). DON is known to alter brain neurochemicals. The serotoninergic system appears to play a role in mediation of the feeding behavior and emetic response. Animals fed low to moderate doses are able to recover from initial weight losses, while higher doses induce more long-term changes in feeding behavior. At low dosages of DON, hematological, clinical, and immunological changes are also transitory and decrease as compensatory/adaptation mechanisms are established. Swine are more sensitive to DON than mice, poultry, and ruminants, in part because of differences in metabolism of DON, with males being more sensitive than females. The capacity of DON to alter normal immune function has been of particular interest. There is extensive evidence that DON can be immunosuppressive or immunostimulatory, depending upon the dose and duration of exposure. While immunosuppression can be explained by the inhibition of translation, immunostimulation can be related to interference with normal regulatory mechanisms. In vivo, DON suppresses normal immune response to pathogens and simultaneously induces autoimmune-like effects which are similar to human immunoglobulin A (IgA) nephropathy. Other effects include superinduction of cytokine production by T helper cells (in vitro) and activation of macrophages and T cells to produce a proinflammatory cytokine wave that is analogous to that found in lipopolysaccharide-induced shock (in vivo). To what extent the elevation of cytokines contributes to metabolic effects such as decreased feed intake remains to be established. Although these effects have been largely characterized in the mouse, several investigations with DON suggest that immunotoxic effects are also likely in domestic animals. Further toxicology studies and an assessment of the potential of DON to be an etiologic agent in human disease are warranted.
A variety of estrogenic compounds exist in the environment, both natural (phyto- and fungal estrogens) and synthetic (e.g. pesticides, industrial contaminants). Recent studies have suggested that a number of reproductive abnormalities in wildlife and human populations could be due to embryonic exposure to ecoestrogens. These abnormalities include modifications in gonadal structure and functioning, abnormalities in genital morphology and size, depressed plasma sex steroid concentrations and various reproductive organ cancers. We review briefly some of these studies as well as those providing data that identify various ecoestrogens. The data to date suggest that a wide variety of compounds can interact with the estrogen receptor and can stimulate estrogen-associated responses. Compared with 17β-estradiol, ecoestrogens have a weak binding affinity for the estrogen receptor and thus have been described as weak estrogens. However, we hypothesize that the estrogenic action of these compounds is augmented by their bioavailability and persistence. Initial testing demonstrates that some ecoestrogens show relatively little affinity for plasma binding proteins; thus, the majority of the estrogenic compound in the plasma is available for translocation into the cell. Likewise, many synthetic ecoestrogens appear to persist for months or years, stored in body fat. Future research needs to examine in more detail the relative roles of receptor affinity, cellular availability, and nuclear persistence in determining the estrogenicity of ecoestrogens. Only then, will we begin to understand the true role of these compounds in ecosystems.
Young male and female pigs were dosed orally with either 0, 5, 10 or 15 mg/kg BW of purified zearalenone. Blood samples taken for the next 7 h contained both conjugated zearalenone (139–317 ng/mL) and α-zearalenol (65–319 ng/mL). In most cases the zearalenone concentration exceeded that of α-zearalenol. Urine samples collected from male pigs contained high levels of conjugated zearalenone (42–197 μg/mL) and α-zearalenol (5–80 μg/mL). One week later, reproductive tracts of females that had received the zearalenone were greatly enlarged compared with controls. Male reproductive tracts tended to be smaller in animals receiving the toxin compared with controls. Key words: Pigs, zearalenone, mycotoxin, metabolism
This study investigates the direct estrogen receptor interactions and the character of the biological activities of three estrogenic resorcylic acid lactones in the immature rat uterus. These compounds are fungal metabolites (P-1492; zearalenone) or derivatives thereof (P-1496 and P-1560; epimeric zearalanols) that have been associated with estrogenizing syndromes in cattle fed mold-infected grain. The compounds compete with estradiol for binding to the cytoplasmic receptor (P- 1496, 13.6%; P-1492, 1.8%; P-1560, 0.8% that of estradiol), and they translocate estrogen receptor sites to the nucleus, with P- 1496 showing the most prolonged nuclear receptor interaction. The three compounds induce the synthesis of the uterine induced protein (P-1496 > P-1560 > P-1492) and increase uterine weight. Direct binding studies with the most potent compound P-1496, in tritium-labeled form indicates a Kd of 1.8 nM (compared to 0.12 nM for estradiol) for interaction with uterine cytoplasmic receptor. Cytoplasmic receptor complexes with [³H]P-1496 sediment at 8S on low salt sucrose density gradients, as do [&HJestradiol receptor complexes. After uterine uptake of [³H]P-1496, salt-extracted nuclear receptor complexes sediment at 5.4S on 0.4 M KC1 sucrose density gradients, as do the nuclear [³H]estradiol receptor complexes. These studies document that despite the unique chemical nature of these resorcylic acid lactones, they interact directly with the estrogen receptor and evoke many of the same biological and biochemical responses that are evoked by the natural estrogen estradiol.
The enzymes 3α- and 3β-hydroxysteroid dehydrogenase (3α- and 3β-HSD) play a pivotal role in synthesis of various steroid hormones
including oestradiol and testosterone. The structure of the mycotoxin zearalenone resembles many characteristics of steroids
and binds to oestrogen receptors as an agonist. Consequently, it is suggested that zearalenone is also a substrate for 3α-HSD
and 3β-HSD. 3α-HSD and 3β-HSD isoforms are expressed in the liver and kidney but also in many steroidogenic tissues. It was
the aim of the present study to demonstrate the presence of these enzymes in granulosa cells, which were obtained from bovine
and porcine ovaries, and to investigate whether zearalenone is a substrate for these enzymes. The results show a species-specific
expression pattern in the granulosa cells of both species. Moreover, it was demonstrated that zearalenone when added to the
culture medium, is converted into α-zearalenol and β-zearalenol. Corresponding to the apparent expression profile, in porcine
granulosa cells predominantly α-zearalenol was formed, whereas bovine granulosa cells preferentially converted zearalenone
into β-zearalenol. This is the first report demonstrating the extrahepatic biotransformation of zearalenone in target tissues.
1. The relative binding affinity of zearalenone, α-zearalenol and β-zearalenol for estrogen receptors was determined in the pig, rat and chicken.2. Similar relative binding patterns were observed, with a-zearalenol exhibiting greater affinity than zearalenone and β-zearalenol the least binding affinity in all species.3. The relative binding affinity of α-zearalenol was greater in pig, than in rat and significantly greater than in chicken.4. Interspecies differences in zearalenone sensitivity may be due to the binding affinity of α-zearalenol for estrogen receptors and differences in zearalenone metabolites formed.
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Concentrations of 25, 50, or 100 ppm of 95% purified zearalenone fed to groups of healthy, multiparous sows during preestrus or throughout the gestation period (or both) produced multiple reproductive deficiencies. These reproductive disorders included infertility, constant estrus, pseudopregnancy, diminished fertility, reduced litter size, smaller offspring, malformation, juvenile hyperestrogenism, and probably fetal resorption. Gross and histologic examinations of sows revealed lesions in the reproductive organs. Marked epithelial changes characterized by squamous metaplasia were noticed in the uterus, uterine duct, cervix, vagina, and mammary glands.
The interactions of phytoestrogens with estrogen receptors were studied in the human breast cancer cell line, MCF-7. The compounds tested were coumestrol, genistein, and formononetin and the mycotoxins, zearalenone and its reduced derivative, zearalenol. All but formononetin compete for binding of [3H]-estradiol to unfilled cytoplasmic estrogen receptor or unfilled nuclear estrogen receptor sites. Relative binding affinities are zearalenol HMP (high melting point isomer) greater than zearalenol LMP (low melting point isomer) greater than zearalenone = coumestrol greater than genistein greater than formononetin. Dissociation constants estimated from competition curves show that binding affinities are high. In contrast to estradiol, phytoestrogens bind only weakly to sex steroid-binding globulin; they also do not bind to corticosteroid-binding globulin. These compounds translocate the cytoplasmic estrogen receptor and bind to unfilled nuclear estrogen receptors in whole cells. Bound nuclear receptors are then processed in a manner similar to estradiol in a step which rapidly decreases total cellular estrogen receptors. The phytoestrogens are also biologically active; they can markedly enhance tumor cell proliferation. In sum, phytoestrogens interact with the estrogen receptors of human breast cancer cells in culture and, therefore, may affect estrogen-mediated events in these cells.
Mycotoxins are considered unavoidable contaminants in foods and feeds because agronomic technology has not yet advanced to the stage at which preharvest infection of susceptible crops by fungi can be eliminated. The aflatoxins have received greater attention than any of the other mycotoxins because of their demonstrated carcinogenic effects in susceptible animals and their acute toxic effects in humans. Since 1965, the U.S. Food and Drug Administration (FDA) has enforced regulatory limits on the concentrations of these toxins in foods and feeds involved in interstate commerce. The FDA routinely monitors the food and feed industries through compliance programs to ensure that the levels of exposure to these toxins are kept as low as practical. This report summarizes data generated from compliance programs on aflatoxins for the fiscal years 1989, 1990, and the first half of 1991. Commodities sampled included peanuts and peanut products, tree nuts, corn and corn products, cottonseed, and milk. Higher than usual levels of contamination were found in corn examined from all areas of the United States in 1989 as a result of the severe drought that affected the 1988 corn crop. The drought in parts of the South and Southeast in 1990 resulted in increased contamination in corn and peanuts from those areas. A review of the surveillance data obtained on deoxynivalenol, zearalenone, ochratoxin A, sterigmatocystin, penicillic acid, and patulin over the years along with available toxicological data for these mycotoxins indicated that no regulatory actions were warranted. The lack of sufficient surveillance data on other mycotoxins that occur in the United States can be attributed in part to the unavailability of reliable analytical methodology.
Feeding trials were conducted to evaluate the effect of including deoxynivalenol (DON)-contaminated oats to provide approximately 0.5, 1.0, 2.0 and 4.0 mg/kg in the complete diets of growing pigs with initial weight of 25 kg. Performance was recorded as weight gain, feed intake, efficiency of feed utilization and carcass quality. Restricted feeding was compared to ad libitum feeding. For the groups fed diets containing 2 and 4 mg/kg of DON, a dose-related decrease in weight gain was observed during the first 8 weeks on experimental diets. With 4 mg/kg DON there were decreased feed intake, weight gain and efficiency of feed utilization throughout the experiment. No effect was observed in groups fed diets containing 0.5 or 1.0 mg/kg of DON. The carcass quality was not affected in any group.
Experiments were carried out in order to study the effect of known quantities of zearalenone on reproductive performance of gilts. Zearalenone was produced on autoclaved corn using pure cultures of Fusarium graminearum Schwabe (local strain of Leskovac). The amount of 22.09 mg/kg of zearalenone in the ration of breeding gilts had an obvious harmful effect on their reproductive performance decreased number of corpora lutea, decreased weight of ovaries, decreased number of live embryos, increased number of dead-born piglets, and the occurrence of abortus. These effects were less pronounced in gilts fed mashes containing 2.2 mg/kg zearalenone. However, in both groups the uterotropic effect of zearalenone was obvious.
At an average age of 70 d, 60 Yorkshire gilts born either in July (Trial 1; n = 30) or August (Trial 2; n = 30) received a diet containing zearalenone for 0 (control), 45 or 90 d. The concentration of zearalenone in diets was 2 ppm for 2 wk and 1.5 ppm for the remainder of the study. Vulval swelling and reddening was evident within 7 d after zearalenone was first fed. Zearalenone consumption had no effect on BW or backfat depth. Puberty occurred in Trial 1 at 219 +/- 6 d and was not influenced by zearalenone. Gilts in Trial 2 were divided into two groups; blood samples were taken from 12 gilts to assess pulsatile LH patterns and LH response to estradiol benzoate (EB) and 18 were handled similarly to those in Trial 1. Of this latter subgroup, age at puberty was younger (P less than .05) with zearalenone (217 +/- 7.0, 193 +/- 9.1 and 185.6 +/- 8.2 d for 0-, 45-, and 90-d treatments). Prepubertal consumption of zearalenone did not affect conception rates, ovulation rates, number of fetuses or percentage of embryo survival following mating at pubertal estrus. Two days before the 90-d experimental period ended for Trial 2, blood samples were taken from 12 gilts (four/treatment) every 15 min for 4 h prior to injection of EB (10 micrograms/kg) and every 6 h for 108 h after EB. Analysis of pulsatile patterns of LH revealed no influence of zearalenone on the number of peaks/4 h, baseline concentration or peak height.(ABSTRACT TRUNCATED AT 250 WORDS)
The uptake of the naturally occurring 3-alpha-hydroxy isomer of T-2 toxin (alpha-T-2 toxin) was investigated in a murine B cell hybridoma as a model for trichothecene-lymphocyte interactions. alpha-[3H]T-2 toxin was prepared by oxidation of T-2 toxin and reduction with [3H]NaBH4 followed by normal phase and reverse phase high-performance liquid chromatography. Uptake of alpha-[3H]T-2 toxin by hybridoma cells was both time- and concentration-dependent. The antibiotic anisomycin inhibited uptake of alpha-[3H]T-2 toxin by hybridoma cells, which suggests ribosomal involvement in the uptake mechanism. Uptake of alpha-[3H]T-2 toxin was also inhibited by verrucarin A, roridin A and deoxynivalenol, and the inhibition followed a trichothecene structure-activity rank similar to that established for protein synthesis inhibition and in vivo toxicity. The characteristics of uptake of alpha-[3H]T-2 toxin by isolated splenocytes were qualitatively similar to those of the hybridoma but accumulation at equilibrium was less. Accumulation of alpha-[3H]T-2 toxin by erythrocytes, cells lacking ribosomes, did not increase with time and was not affected by the presence of unlabelled toxin. The results suggested that specific accumulation and uptake of alpha-[3H]T-2 toxin by the murine B cell hybridoma and spleen cells were highly consistent with a model based on intracellular binding of T-2 toxin to ribosomes.
Sixteen primiparous sows were bred and fed either a control ration (n = 8) or a diet containing purified zearalenone (n = 8; 1 mg/kg of body weight) from days 7 to 10 after breeding. On day 7 after breeding, the jugular vein of each sow was cannulated and blood was collected at 20-minute intervals for 4 hours before feeding and 4 hours after feeding. On day 10 after breeding, blood samples were collected from 4 control sows and 4 zearalenone-fed sows at 20-minute intervals for 4 hours before collection of blastocysts. A similar blood sampling schedule was followed for the remaining 4 control and 4 zearalenone sows on day 14 after breeding. On day 10 after breeding, spherical blastocysts were recovered from all control sows and from 3 of 4 zearalenone-treated sows. Average diameter of blastocysts from zearalenone-treated sows were similar to that of control sows. On day 14 after breeding, blastocysts were recovered from all control sows and 3 of 4 zearalenone-treated sows. Blastocysts from the control sows were filamentous, whereas blastocysts from zearalenone-treated sows were fragmented and contained foci of necrosis. Incidence of luteinizing hormone (LH) secretory spikes per sow was less (P less than 0.01) in zearalenone-treated sows (0.25 +/- 0.25/4 h) than control sows (1.75 +/- 0.25/4 h) on day 10 after breeding. Incidence of follicle-stimulating hormone (FSH) secretory spikes was similar (P = 0.45) among treatments on days 7, 10, and 14 after breeding.(ABSTRACT TRUNCATED AT 250 WORDS)
1. The relative binding affinity of zearalenone, alpha-zearalenol, and beta-zearalenol for estrogen receptors was determined in the pig, rat and chicken. 2. Similar relative binding patterns were observed, with alpha-zearalenol exhibiting greater affinity than zearalenone and beta-zearalenol the least binding affinity in all species. 3. The relative binding affinity of alpha-zearalenol was greater in pig, than in rat and significantly greater than in chicken. 4. Interspecies differences in zearalenone sensitivity may be due to the binding affinity of alpha-zearalenol for estrogen receptors and differences in zearalenone metabolites formed.
The binding of radiolabeled T-2 to eukaryotic ribosomes was studied. The toxin bound to ribosomes in a time-, temperature- and concentration-dependent manner. The binding was saturable (0.3 nM), reversible at 37 degrees (half-time approximately 2.5 hr) and specific. The stoichiometry was one toxin molecule bound per ribosome. Binding of T-2 appeared to stablize the toxin recognition site to thermal degradation. A synthetically derived epimer of T-2 bound to the same ribosomal site as authentic T-2, but apparently with lower affinity. Two other trichothecene toxins tested blocked the binding of T-2 to ribosomes in a manner reflecting their protein synthesis inhibitory potencies. Anisomycin blocked the binding of T-2 to both isolated ribosomes and cells, whereas emetine blocked binding only to cells. Our data, together with that in the accompanying paper (Middlebrook JL and Leatherman DL, Biochem Pharmacol 38: 3093-3102, 1989), suggest that T-2 interaction with CHO cells is best viewed as a free, bidirectional movement of toxin across the plasma membrane and specific high-affinity binding to ribosomes.
Mature gilts (n = 16) were hand mated and randomly assigned to 1 of 4 groups of 4 gilts each. Treated gilts had 108 mg of purified zearalenone added to their diet on postmating days (PMD) 2 to 6, 7 to 10, or 11 to 15. Control gilts were given the same diet without added zearalenone. On PMD 6, 10, and 15, control gilts had venous cannulas placed in the jugular vein, and blood samples were taken at 20-minute intervals for 4 hours before feeding and 4 hours after feeding. Samples were collected from treated gilts on the last day that zearalenone was consumed. Samples were analyzed for follicle stimulating hormone, luteinizing hormone (LH), and prolactin. Single blood samples were taken by venipuncture on PMD 8, 12, 16, 20, 24, and 28 and at euthanasia and were analyzed for serum concentration of progesterone and estradiol-17 beta. All gilts were euthanatized 30 to 32 days after mating, and fetal development was assessed. Three gilts that were given zearalenone on PMD 7 to 10 were not pregnant and had regressing corpora lutea on the ovaries at euthanasia. All other treated and control gilts were pregnant. Serum samples from treated gilts on PMD 10 and 15 had lower mean prolactin concentrations than did those from controls. The number of LH spikes were fewer (P less than 0.05) in gilts that were given zearalenone on PMD 15 compared with those in controls on PMD 15. Serum progesterone concentrations indicated that corpora lutea regressed between PMD 20 and 28 in nonpregnant gilts.(ABSTRACT TRUNCATED AT 250 WORDS)
Homogenized intestinal mucosa samples from sows were incubated with zearalenone in the presence of NADPH or UDPGA. In addition, UDPglucuronosyltransferase activity in the microsomal fraction of mucosa was determined using 1-naphthol as substrate. In the presence of NADPH, zearalenone was reduced to both alpha- and beta-zearalenol (0.37 +/- 0.18 and 0.29 +/- 0.11 nmol/mg protein/hr in the duodenum and jejunum, respectively). The beta-isomer was the predominant metabolite. Glucuronide conjugation of zearalenone was very high compared with the level of reduction occurring (11.3 +/- 6.1 and 9.4 +/- 5.8 nmol conjugated/mg protein/hr in the duodenum and jejunum, respectively). There was no correlation between the rates of glucuronide conjugation of zearalenone and 1-naphthol, indicating that they depend upon two different isoenzymes of UDPglucuronosyltransferase.
Trans-zearalenone, a resorcylic acid lactone, also known as F-2 toxin, is a nonsteroidal estrogenic mycotoxin produced by numerous species of Fusarium. As a result zearalenone is found in a number of cereal crops and their derived food products. A closely related substance "zeranol" (zearalanol) is at present being used in the United States and Canada as an anabolic agent in beef cattle. Zearalenone has been implicated in numerous incidences of mycotoxicosis in farm animals, especially pigs. In this report the health risks to Canadians due to the presence of zearalenone in food products have been evaluated. The first part of the report deals with the physicochemical aspects, mycology, laboratory production, and natural occurrence in plant products and animal products of zearalenone. The stability of zearalenone in foods and feeds, the effects of food processing, and the removal from foods and feeds by physicochemical means are also discussed. From these data the daily exposure of Canadians to zearalenone from food consumption has been estimated to be in the range of 0.05-0.10 microgram/kg b.w./day (mean and 90th percentile of eaters, respectfully) for young children, the highest consumption group on a body weight basis. The second part of the report deals with the metabolic disposition of zearalenone as well as the available toxicity data base of zearalenone in laboratory animals, farm animals, and humans. Studies in various species (rodents, rabbits, pigs, monkeys) including man have shown that zearalenone has estrogenic and anabolic activity. Its major effects are on reproduction, including reproductive organs and their function, leading to hyperestrogenism. Zearalenone has been implicated in numerous incidences of hyperestrogenism in farm animals, especially pigs. For reproductive effects a no adverse effect level (NOAEL) of 0.06 mg/kg b.w./day was estimated for the pubertal pig, the most sensitive species tested. Important differences in the biotransformation of zearalenone were noted, with greater amounts of alpha-zearalenol, the more estrogenic metabolite, formed in man and the pig compared to rodents. In addition, the biological half-life of these substances was longer in man than in other species tested. The binding of zearalenone to estrogen receptors was approximately 20-fold lower than that seen with 17 beta-estradiol in several assays.(ABSTRACT TRUNCATED AT 400 WORDS)
A field case is described in which all prepuberal swine of a group of 20 pigs and 11 sows showed marked estrogenic effects. These consisted of enlarged mammary glands, swelled tumefacient vulva, and greatly enlarged internal reproductive organs. The corn used to feed these animals was found to contain 56 ppm zearalenone. Deoxynivalenol (4.9 ppm) was found in the corn; T-2 toxin, nivalenol, fusarenon-X, diacetoxyscirpenol, aflatoxins and ochratoxins were absent. Identity of Z was confirmed by TLC in four solvent systems, behavior of the suspected spots under UV light of different wavelengths, change of fluorescence from green to blue after spraying with 5% AlCl3 in alcohol and heating at 110 degrees C during 5 minutes, and by its UV spectrum. A zearalenone producing strain of Fusarium oxysporum was isolated from the suspected grain. Histopathology of uterine tissue showed typical changes produced by zearalenone: hyperplasia, hypertrophy, and metaplasia of the myometrium. Feeding of the grain to a prepuberal sow under controlled conditions reproduced all the effect found in the farm animals. This is the first field case of zearalenone poisoning reported in Argentina.
One prepubertal gilt, fed 192 micrograms zearalenone/kg body weight/day for 4 days, showed plasma concentrations of alpha-zearalenol 3-4 times higher than of the parent compound during the treatment. Zearalenone and alpha-zearalenol could be traced in plasma until the 5th day and in urine until the 4th day of the posttreatment period. A maximum circulating amount of zearalenone plus alpha-zearalenol, 10.4 ng/ml plasma, was found on the 4th day of treatment followed by an urinary excretion of 305 ng/ml urine. All zearalenone and alpha-zearalenol in plasma and urine were bound to glucuronic acid. On the second day of treatment the animal showed oedema and reddening of the vulva which became more pronounced during the treatment. Hormone analysis, however, showed that the animal had no oestrus cycle during the 3 week experimental period.
Recent studies suggest that T-2 toxin interacts with cell membranes and alters membrane function. This study was done to assess the effect of T-2 toxin on a broad range of cell membrane functions in L-6 myoblasts. The following parameters were assessed after exposure to T-2 toxin for 10 min: (1) the uptake of calcium, rubidium, and glucose; (2) the uptake of leucine and tyrosine and incorporation into protein; (3) the uptake of thymidine and incorporation into DNA; and (4) residual cellular lactate dehydrogenase (LDH) as a measure of cell membrane integrity. The effects of T-2 toxin on these parameters were: (1) The minimal effective concentration (MEC) of T-2 toxin that caused a reduction in the uptake of calcium and glucose was 4 pg/ml. The uptake of rubidium was increased at 0.4 pg/ml and then reduced at 4 pg/ml and higher concentrations. (2) The MEC for reduction of the uptake of leucine and tyrosine and their incorporation into protein was 4 pg/ml. (3) Thymidine uptake and incorporation into DNA showed a biphasic response with an increase at 0.4 pg/ml and a reduction at 4 pg for uptake and 40 pg/ml for incorporation. (4) Intracellular LDH was reduced at 4 ng/ml. (5) Calcium efflux was reduced after 1-, 5-, and 15-min exposures to T-2 toxin in a concentration of 40 ng/ml. All of the changes noted, including protein synthesis inhibition, were present to a significant degree within 10 min of exposure to T-2 toxin. This time interval is too short to attribute all of these effects directly to protein synthesis inhibition since most short-lived proteins have half-lives measured in hours. In conclusion, T-2 toxin appears to have multiple effects on cell membrane function at very low concentrations (0.4 pg/ml to 4 ng/ml), which are independent of protein synthesis inhibition. These likely include effects either direct or indirect on amino acid, nucleotide, and glucose transporters, as well as calcium and potassium (rubidium) channel activities.
Since chemical modulation of gap-junctional intercellular communication has been implicated in several toxicological endpoints, a study to examine the ability of several biological toxins to inhibit this process was undertaken. Eight biological toxins were tested for their ability to inhibit metabolic cooperation, a measure of gap-junctional intercellular communication, in the Chinese V79 cell system. Aplysiatoxin, anhydrodebromoaplysiatoxin and debromoaplysiatoxin showed the strongest ability to inhibit metabolic cooperation while T2-toxin and vomitoxin inhibited metabolic cooperation to a lesser degree. Aflatoxin B1, aflatoxin B2 and palytoxin were inactive in the Chinese V79 system. Palytoxin, which was extremely cytotoxic, might act as a tumor promoter if it induces compensatory hyperplasia in vivo.
The Fusarium mycotoxin, 4-deoxynivalenol, is an abundant, natural contaminant of corn and wheat. 8-Oxo-12,13-epoxytrichothecenes related to 4-deoxynivalenol were synthesized; they either lacked the 7-hydroxyl but contained a hydroxyl at C-4 (7-deoxynivalenol) or lacked substituents at C-3 and C-7 (3,7-dideoxynivalenol). The ability of these synthetic analogs and their acetylated derivatives to inhibit protein synthesis by cultured mammalian cells was compared to that of 4-deoxynivalenol. Whereas the 50% inhibitory dose (ID50) for murine erythroleukemia cells was about 1 microgram/ml for 4-deoxynivalenol and 3,7-dideoxynivalenol, all of the other analogs were at least 10-fold less potent. When tested at their ID50 dose, all of the 8-oxotrichothecenes, except 4-deoxynivalenol and 3,7-dideoxynivalenol, caused polysome 'run-off', indicating that, at this dose, they are inhibitors of polypeptide chain initiation. With 4-deoxynivalenol and 3,7-dideoxynivalenol, polysomes remained at control levels indicating that these toxins prevent polypeptide chain elongation. From these results and comparisons to previous studies of 8-oxo-12,13-epoxytrichothecenes (trichothecolone, trichothecin, nivalenol and fusarenone X), trichothecenes with substituents at both C-3 and C-4 predominantly inhibit polypeptide chain initiation, whereas those lacking one substituent at either site are inhibitors of chain elongation.
Nineteen 12,13-epoxytrichothecene mycotoxins were tested for their relative capabilities to inhibit protein synthesis in Vero cells and rat spleen lymphocytes. Although the lymphocytes were generally more sensitive to the mycotoxins, good correlation existed between the relative potencies of the various trichothecenes in the two cell systems. The most potent mycotoxins (T-2, verrucarin A and roridin A) have acetyl side groups on, or a hydrocarbon chain between, carbons 4 and 15 of the basic ring structure. Loss of side groups from either of these positions or an isovaleryl group at carbon 8 resulted in reduced protein synthesis inhibition (T-2 to HT-2, neosolaniol or diacetoxyscirpenol). Any combination of loss from all three positions (T-2 triol, T-2 tetraol, 15-monoacetyl DAS, scirpentriol, fusarenon X and deoxynivalenol) further weakens their effect. Reduction of the hydroxyl groups to hydroxides, forming verrucarol and deoxyverrucarol, reduced their effectiveness by over a thousand-fold compared to the most potent mycotoxins. Addition of side groups resulted in reduced effectiveness only when an acetyl group was added to the carbon 3 position of T-2 (acetyl T-2) and deoxynivalenol (3-acetyl deoxynivalenol) or on substitution of an epoxide across the 9,10 carbons of diacetoxyscirpenol (beta-epoxide DAS). Effects of combining these and other mycotoxins were additive and showed no synergism or competition for binding to the active site. When in vitro effects of the mycotoxins were compared with results from whole animal lethality tests, several of the trichothecenes were weak inhibitors of protein synthesis in vitro but had in vivo toxicities similar to that of T-2 toxin. Thus, the in vitro cell response of a given trichothecene is not always an accurate predictor of toxicity in whole animals.
Binding of some selected steroids and anabolic agents to bovine sex-hormone binding globulin (SHBG) was investigated. SHBG binding affinities, relative to the reference hormone 5 alpha-dihydrotestosterone, were estimated for the compounds. The results demonstrate that binding of steroid hormones to SHBG is facilitated by the 17 beta-hydroxyl group, possibly involving hydrogen binding, and by the methyl group at C-19 of the steroid moiety. Structural modifications at C-17 of a steroid molecule involving esterification, epimerization or reduction of the 17 beta-hydroxyl group, or introduction of a bulky 17 alpha group have the effect of decreasing the SHBG binding affinity of the steroid molecule.
Tamoxifen (TAM), which binds to estrogen receptors and can act as an estrogen antagonist, was incorporated into the diets of swine and mink to determine if it would ameliorate the effects of the estrogenic mycotoxin zearalenone (ZEN). Sows and female mink were fed diets containing 2 ppm (swine) or 20 ppm (mink) ZEN and/or 10 ppm TAM from day 30 of gestation through weaning (swine) or from 2 months prior to breeding through weaning (mink). The diets containing ZEN and/or TAM did not adversely affect reproduction in the sows. Although some hyperestrogenic effects on testes, uterine and ovarian weights were observed in the F1 piglets at 21 days of age, subsequent breeding performance was not affected. All the female mink exposed to ZEN mated, but only 25% whelped. No mink fed TAM (singly or in combination with ZEN) mated. Necropsy of these unmated females fed TAM revealed consistent severe pyometra. Histological examination of the reproductive tracts of the ZEN, TAM and ZEN + TAM-treated mink showed similar alterations, including ovarian follicular atrophy and degeneration, and mild to severe uterine atrophy, pyometra and endometritis. The results of these studies indicate that TAM was not effective in ameliorating the hyperestrogenic effects of ZEN in swine and mink, but rather it acted as an estrogen agonist.
The effects of low dietary concentrations of Fusarium mycotoxins (deoxynivalenol (DON), 15-acetyl-DON, and zearalenone) on growth, immunological, and hematological parameters were determined in young pigs during a 28-day feeding experiment. Clean and naturally contaminated corn were incorporated into basal diets formulated to contain 0.00, 0.75, 1.50, and 3.00 mg DON/kg diet. A pair-fed control animal was used for comparison with each animal receiving the highest level of contamination (diet 4). Skin temperature, measured during the first week of the experiment, decreased linearly as the dietary mycotoxin concentration increased. Several other linear effects were observed: depressed feed intake throughout the experiment, reduction in thyroid size (absolute/relative), and changes in the appearance of the esophageal region of the stomach (thicker and higher degree of folding with increasing toxin concentration). Serum T4 (thyroxine) levels increased quadratically after 7 and 28 days of exposure compared to control animals. This change coincided with an increase in albumin levels, a decrease in alpha-globulin levels, and an overall increase in albumin/globulin ratio as the level of contamination increased. After immunization with sheep red blood cells (SRBC), animals fed contaminated diets showed a delayed response in peak titers. At the end of the experiment an increase in the segmented neutrophil count was observed. The following observations were made for animals consuming diet 4 as compared to the pair-fed controls: lower skin temperature, better feed efficiency, more corrugated stomachs, reduced alpha-globulin levels, and lower antibody titers to SRBC.(ABSTRACT TRUNCATED AT 250 WORDS)
A feeding trial with naturally deoxynivalenol (DON)-contaminated oats included in feed mixtures at graded levels was conducted in growing pigs. The DON concentrations were 0, 0.7, 1.7, and 3.5 mg/kg of complete feed mixture givenad libitum to different groups. The data recorded were feed consumption, body weight gain, slaughter weight, biochemical and haematological data including serum immunoglobulin A, clinical condition and post-mortem pathology including histopathology.
Significantly decreasing body weight gain throughout the experimental period, decreased slaughter weight and reduced feed utilization efficiency were observed for the group fed a diet containing 3.5 mg/kg of DON. At the same DON concentration, there were increased liver weights and decreased concentrations of serum protein and albumin, and a temporary fall in packed blood cell volume, serum calcium and serum phosphorus. For the groups fed diets containing 1.7 and 3.5 mg/kg of DON, a statistically significant, dose-related decrease in daily feed consumption was observed. No other effects on haematological, biochemical or immunological parameters were recorded. The carcass quality was not affected in any group.
It was concluded that significant effects in growing pigs may be observed at a dietary DON concentration of 1.7 mg/kg, originating from naturally contaminated oats included in a diet that was otherwise adequate and contained only minor traces of other mycotoxins.
The disposition of the estrogenic mycotoxin, zearalenone (ZEN) in female, 10- to 14-week-old Yorkshire pigs was investigated. Pigs were administered [3H]ZEN intravenously (IV; n = 4; 5 mg/kg; 15 microCi/kg), orally (n = 4; 10 mg/kg; 30 microCi/kg), or intravenously with bile removal (IVB; n = 2; 5 mg/kg; 15 microCi/kg). Plasma, urine, feces, and bile (IVB pigs only) were serially collected and analyzed for radioactivity. Metabolite profiles were determined in plasma and bile by HPLC. The biological half-life of total plasma radioactivity in IV and orally dosed pigs (86.6 hr) was much larger than that of IVB animals (3.34 hr). Metabolite profiles of plasma concentration vs time demonstrated secondary peaks in concentration during the terminal elimination phase in IV and orally dosed pigs. In IVB pigs these peaks were absent, relative metabolite profiles were altered, and ZEN and metabolites were no longer detectable after 16 hr post-dosing. Biliary recovery of radioactivity, principally as glucuronide conjugates, was extensive (45.61 +/- 4.7%) in IVB pigs and significantly greater (p < 0.05) than that of fecal recovery of radioactivity in IV (6.56 +/- 0.78) or orally dosed (21.74 +/- 1.56%) pigs. Intraduodenal administration of bile containing [3H]ZEN and metabolites resulted in recovery of 64.56 +/- 4.89% of the dose in bile, 20.78 +/- 3.94% in urine, and the presence of glucuronide conjugates of ZEN and alpha-zearalenol (ZEL) in portal and jugular plasma. Differences in metabolite profiles between administered bile and sampled plasma suggest that the intestinal mucosa was active in reducing ZEN to ZEL and conjugating these metabolites with glucuronic acid. These studies provide evidence for extensive biliary secretion and enterohepatic cycling of ZEN and metabolites in pigs.
The objectives of this review are to provide 1) information on the FDA Feed Contaminants Program, 2) the legal history of aflatoxins and their current action levels, 3) a report on the levels of aflatoxins, fumonisins, vomitoxin, ochratoxin A, and zearalenone in domestic and import surveillance samples of feed during fiscal years 1989 through 1992, and 4) information on naturally occurring toxins encountered recently by the Center for Veterinary Medicine. Ten of 644 (1.6%) domestic corn samples and 7 of 106 (6.6%) domestic cottonseed samples contained aflatoxins at levels > 300 ppb. The mean fumonisin level in the 1990 survey of 85 corn screening samples was 12.1 ppm, and the values ranged from 2.6 to 32 ppm. The mean vomitoxin levels in the 1991 survey of 207 winter wheat samples and 206 spring wheat samples was 2.4 and .9 ppm, respectively. Ochratoxin A was not detected in 168 samples. Zearalenone was detected at levels > .15 ppm in only 1 of 161 samples. Cottonseed containing 13,000 ppm gossypol was recently implicated in the deaths of dairy cows. Crambe meal and canola meal are sanctioned for use in feed with certain restrictions, including the levels of glucosinolates. The FDA is continuing its surveillance and will strive to provide guidance on the increasing number of naturally occurring toxins.
An outbreak of zearalenone mycotoxicosis occurred between early March and mid-April involving 62 suckling piglets of both sexes. The clinical picture was characterized by edematous swelling and reddening of the vulva, sometimes associated with reddening and/or necrosis of the tail. Six female piglets had congenital lesions of the external genitalia while in the remainder clinical signs appeared 2 to 3 d after birth. No sows ingesting the contaminated feed had signs of hyperestrogenism. The distribution of affected litters showed a correlation with poor hygienical conditions. Zearalenone residues were detected only in feed samples from mangers where the hyperestrogenic syndrome occurred.
Trichothecene mycotoxins are a group of structurally similar fungal metabolites that are capable of producing a wide range of toxic effects. Deoxynivalenol (DON, vomitoxin), a trichothecene, is prevalent worldwide in crops used for food and feed production, including in Canada and the United States. Although DON is one of the least acutely toxic trichothecenes, it should be treated as an important food safety issue because it is a very common contaminant of grain. This review focuses on the ability of DON to induce toxicologic and immunotoxic effects in a variety of cell systems and animal species. At the cellular level, the main toxic effect is inhibition of protein synthesis via binding to the ribosome. In animals, moderate to low ingestion of toxin can cause a number of as yet poorly defined effects associated with reduced performance and immune function. The main overt effect at low dietary concentrations appears to be a reduction in food consumption (anorexia), while higher doses induce vomiting (emesis). DON is known to alter brain neurochemicals. The serotoninergic system appears to play a role in mediation of the feeding behavior and emetic response. Animals fed low to moderate doses are able to recover from initial weight losses, while higher doses induce more long-term changes in feeding behavior. At low dosages of DON, hematological, clinical, and immunological changes are also transitory and decrease as compensatory/adaptation mechanisms are established. Swine are more sensitive to DON than mice, poultry, and ruminants, in part because of differences in metabolism of DON, with males being more sensitive than females. The capacity of DON to alter normal immune function has been of particular interest. There is extensive evidence that DON can be immunosuppressive or immunostimulatory, depending upon the dose and duration of exposure. While immunosuppression can be explained by the inhibition of translation, immunostimulation can be related to interference with normal regulatory mechanisms. In vivo, DON suppresses normal immune response to pathogens and simultaneously induces autoimmune-like effects which are similar to human immunoglobulin A (IgA) nephropathy. Other effects include superinduction of cytokine production by T helper cells (in vitro) and activation of macrophages and T cells to produce a proinflammatory cytokine wave that is analogous to that found in lipopolysaccharide-induced shock (in vivo). To what extent the elevation of cytokines contributes to metabolic effects such as decreased feed intake remains to be established. Although these effects have been largely characterized in the mouse, several investigations with DON suggest that immunotoxic effects are also likely in domestic animals. Further toxicology studies and an assessment of the potential of DON to be an etiologic agent in human disease are warranted.