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Alfa-Lipoic acid protects testosterone secretion pathway and sperm quality against 4-tert-octylphenol induced reproductive toxicity

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... Additionally, we reviewed research studies to discuss the biochemical mechanisms of lipoic acid's effect on testosterone, providing a conclusive summary. Table 1 presents a comprehensive overview of 20 distinct studies [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52], that directly explore the impact of lipoic acid on testosterone levels in various male reproductive toxicity contexts. Notably, all of these investigations were conducted post-2006 and spanned different countries worldwide, with a predominant focus on Middle Eastern nations, including eight studies from Egypt. ...
... Specifically, lipoic acid has demonstrated its ability to restore the reduction in the testicular antioxidant enzymes, including catalase, superoxide dismutase, glutathione reductase, and glutathione peroxidase. Additionally, it reinstates the testicular content glutathione that results from induced testicular toxicity [34,39,[42][43][44][45]52]. Furthermore, lipoic acid exhibits the capability to reduce the level of malonaldehyde moieties, byproducts of oxidative damage, particularly resulting from peroxidation of polyunsaturated fatty acids (i.e., lipid peroxidation) [42,45,47]. ...
Article
Testosterone extends its impact beyond sexual function, playing a crucial role in shaping overall male health, including aspects such as muscle mass, bone density, mood regulation, and energy levels. Lipoic acid, a cofactor for specific enzymes, particularly dehydrogenases involved in cellular energy production, has been studied for its impact on testosterone. This comprehensive review systematically scoured PubMed and Scopus databases using the keywords "lipoic acid" and "testosterone." It encompassed all relevant English papers published from November 1971 to the present, including full texts and abstracts, along with research elucidating the biochemical mechanisms linking lipoic acid to testosterone. In summary, lipoic acid consistently restores testosterone levels, offering promise as an intervention in testicular health, especially in cases of testicular toxicity caused by various harmful agents. Its mechanisms encompass nitric oxide enhancement, fortification of testicular antioxidants, elevation of luteinizing hormone, enhancement of steroidogenesis, and the maintenance of energy production. These mechanisms underscore the therapeutic potential of lipoic acid for testicular health.
... Treatment with lipoic acid improved the changes in serum male sex hormones induced by acrylamide. These findings correlated with Othman et al. (29) who demonstrated that lipoic acid sustained the levels of cholesterol and sex hormone binding globulin (SHBG) to those seen in the control rats. This finding might be attributed to antioxidant milieu of LA which maintained a fine tuning of signal transduction mechanisms necessary for normal function of hypothalamus-testicular axis leading to normal secretion of testosterone and sperm production. ...
... Treatment of rats with LA showed an increase in the activities of antioxidant enzymes and reduced glutathione level with a decrease in lipid peroxidation which might be attributed to the antioxidant and oxidative damage repairing ability of LA (8). Also, Othman et al. (29) reported a decrease in the levels of TBARS and protein carbonyl with normalized levels of endogenous antioxidants and protection of reproductive markers in the lipoic acid octylphenol treated rats compared to the control rats. El-Beshbishy et al. (33) reported that co-administration of lipoic acid 20 mg/kg orally for 14 days together with bisphenol resulted in decreasing lipid peroxidation and increasing enzymatic and non-enzymatic antioxidants in rats. ...
... Furthermore, it has already been reported that ALA ameliorates the oxidative injury by augmenting endogenous antioxidants such as glutathione, which maintains the process of normal steroidogenesis. This in turn facilitates the regular germ cell proliferation, production of normal sperm, motility and functional competence [24]. Therefore, the present study was aimed to investigate the protective role of ALA in transplacental nicotine-induced germ cell damages. ...
... In the present study, intervention with ALA significantly improved the nicotine-induced decrease in 3β-HSD expression, which indicates that ALA treatment can attenuate the nicotine-induced impaired steroidogenesis. It has been reported that ALA improved the testosterone level and sperm quality by reducing the oxidative stress in rats [24]. Osteocalcin binds to G-protein coupled receptor (GPRC6A) on Leydig cells and promotes the testosterone production and germ cell health. ...
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Background: Smoking during pregnancy is associated with numerous fetal and developmental complications and reproductive dysfunctions in the offspring. Nicotine is one of the key chemicals of tobacco responsible for addiction. The present study was aimed to investigate the protective role of ?-lipoic acid (ALA) during the transplacental nicotine-induced germ cell and DNA damage in the offspring of Swiss mice. Methods: Pregnant mice were treated with nicotine (20 mg/kg/day) in drinking water from 10 to 20 days of gestation period, and ALA (120 mg/kg/day) was administered orally for the same period. Endpoint of evaluation includes general observations at delivery and throughout the study, litter weight and size, sperm count and sperm head morphology, while structural damages and protein expression were assessed by histology and immunohistochemistry, respectively. Results: Maternal nicotine exposure led to decreased growth rate, litter and testicular weight, testosterone level, 3?-HSD expression and sperm count as well as increased sperm head abnormalities, micronucleus frequency and 8-oxo-dG positive cells, and the effects have been restored by ALA supplementation. Conclusions: The present study clearly demonstrated that ALA ameliorates nicotine-associated oxidative stress, DNA damage and testicular toxicity in the offspring by improving steroidogenesis, spermatogenesis and sperm count.
... Treatment with lipoic acid improved the changes in serum male sex hormones induced by acrylamide. These findings correlated with Othman et al. (29) who demonstrated that lipoic acid sustained the levels of cholesterol and sex hormone binding globulin (SHBG) to those seen in the control rats. This finding might be attributed to antioxidant milieu of LA which maintained a fine tuning of signal transduction mechanisms necessary for normal function of hypothalamus-testicular axis leading to normal secretion of testosterone and sperm production. ...
... Treatment of rats with LA showed an increase in the activities of antioxidant enzymes and reduced glutathione level with a decrease in lipid peroxidation which might be attributed to the antioxidant and oxidative damage repairing ability of LA (8). Also, Othman et al. (29) reported a decrease in the levels of TBARS and protein carbonyl with normalized levels of endogenous antioxidants and protection of reproductive markers in the lipoic acid octylphenol treated rats compared to the control rats. El-Beshbishy et al. (33) reported that co-administration of lipoic acid 20 mg/kg orally for 14 days together with bisphenol resulted in decreasing lipid peroxidation and increasing enzymatic and non-enzymatic antioxidants in rats. ...
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Introduction: Acrylamide is very toxic to various organs and associated with significant increase of oxidative stress and depletion of antioxidants. Alpha-lipoic acid enhances cellular antioxidant defense capacity, thereby protecting cells from oxidative stress. Aim of the study: This study aimed to evaluate the protective role of alpha-lipoic acid on the oxidative damage induced by acrylamide in testicular and epididymal tissues. Material and methods: Forty adult male rats were divided into four groups (10 rats each). Control group; acrylamide treated group administered acrylamide 0.05% (w/v) in drinking water for 21 days; alpha-lipoic acid group received basal diet supplemented with 1% alpha-lipoic acid and forth group was exposed to acrylamide and treated with alpha-lipoic acid at the same doses and treatment regimen mentioned before. Results: The administration of acrylamide resulted in significant elevation in testicular and epididymal malondialdehyde level (MDA) and significant reduction in the level of reduced glutathione (GSH) and the activities of glutathione-S-transferase (GST), glutathione peroxidase (GPX) and glutathione reductase (GR). Also, acrylamide significantly reduced serum total testosterone and progesterone but increased estradiol (E2) levels. Treatment with alpha-lipoic acid prior to acrylamide induced protective effects and attenuated these biochemical changes. Conclusion: Alpha-lipoic acid has been shown to possess antioxidant properties offering promising efficacy against oxidative stress induced by acrylamide administration.
... The current study demonstrated that hypothalamus, pituitary, and testis tissues' biochemical parameters or histological characteristics were unaffected by αLA induction. This demonstrated the safety of αLA usage; These outcomes were in agreement with Othman et al. [30], who confirm the welfare induction of αLA. Likewise, the Italian Ministry of Health has not established a maximum daily intake of this dietary supplement, meaning that the use of such molecule is safe [31]. ...
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Objectives: Octylphenol (OP) is a member of the category of substances known as endocrine-disrupting chemicals and can interfere with the actions of steroid hormones, having negative implications on reproductive health. Alpha lipoic acid (αLA), a naturally occurring nutraceutical, has been shown to provide therapeutic benefits due to its antioxidant activity and capacity to reverse oxidative damage. Consequently, the current study is attending to estimate the protective effects of αLA against OP-induced male infertility. Methods: Forty male albino rats were randomly divided equally into four groups. Group I (control group) didn't received any materials, Group II (αLA-group) received alpha lipoic acid (40 mg/Kg/day), group III (OP-group) received octylphenol (50 mg/Kg/day), and group IV (protective group) received octylphenol (50 mg/Kg/day) plus alpha lipoic acid (40 mg/Kg/day) for 30 days. Serum reproductive hormones (gonadotropin releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone, total oxidant status (TOS), and total antioxidant capacity (TAC) levels were measured. Histo-logical and histochemical examinations of the hypothalamus, pituitary gland and testis, as well as immunohistochemical detection for tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the pituitary gland and testis were performed. Results: Rats of OP-group showed significant reduction of serum GnRH, FSH, LH, testosterone and TAC levels and significant rise of TOS levels. In parallel with these outcomes, several histopathological and histochemical abnormalities were observed in their hypothalamus, pituitary and testicular tissues. Additionally these structural abnormalities were associated with increased TNF-α and IL-6 expressions in both pituitary and testicular tissues. On other hand, rats of protective group showed enormous improvements in biochemical, histopathological, and immunohistochemical derangements induced by OP. Insignificant differences in the biochemical, histopathological, and immunohistochemical examinations were observed between control group and αLA-group. Conclusions: Short-term exposure of OP at low doses disturbs the hypothalamic-pituitary-gonadal (HPG) axis associated with increased oxidative stress, inflammation and structural abnormalities with successful reversion of theses derangements by αLA via its antioxidant and anti-inflammatory properties. Keywords: octylphenol; alpha lipoic acid; reproduction; cytokines; oxidative stress
... Our experiment found that treatment with ALA improved the changes in the serum hormones induced by OFO. These findings correlated with Othman, who demonstrated that ALA exerts antioxidant effects to maintain normal hypothalamic-testicular axis function, which leads to normal androgen secretion [60,61]. Our experimental results might be attributed to an antioxidant milieu of ALA which maintained the normal function of the hypothalamic-oviduct axis, leading to normal estrogen secretion. ...
Article
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The development of single enantiomers with high efficiency and low toxic activity has become a hot spot for the development and application of drugs and active additives. The aim of the present study was to investigate the effectiveness of the application of α-lipoic acid with a different optical rotation to alleviate the inflammation response and oxidative stress induced by oxidized fish oil in laying hens. Sixty-four 124-week-old Peking Red laying hens were randomly allocated to four groups with eight replicates of two birds each. The normal group was fed basal diets supplemented with 1% fresh fish oil (FO), and the oxidative stress model group was constructed with diets supplemented with 1% oxidized fish oil (OFO). The two treatment groups were the S-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + S-LA) and the R-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + R-LA) added at 100 mg/kg, respectively. Herein, these results were evaluated by the breeding performance, immunoglobulin, immune response, es-trogen secretion, antioxidant factors of the serum and oviduct, and pathological observation of the uterus part of the oviduct. From the results, diets supplemented with oxidized fish oil can be relatively successful in constructing a model of inflammation and oxidative stress. The OFO group significantly increased the levels of the serum inflammatory factor (TNF-α, IL-1β, IL-6, and IFN-γ) and the oxidative factor MDA and decreased the activity of the antioxidant enzyme (T-AOC, T-SOD, GSH-Px, GSH, and CAT) in the oviduct. The addition of both S-LA and R-LA significantly reduced the levels of serum inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), increased the activity of antioxidant indexes (T-AOC, T-SOD, GSH-Px, GSH, and CAT), and decreased the MDA contents in the serum and oviduct. Meanwhile, the supplementation of S-LA and R-LA also mitigated the negative effects of the OFO on the immunoglobulins (IgA and IgM) and serum hormone levels (P and E2). In addition, it was worth noting that the R-LA was significantly more effective than the S-LA in some inflammatory (IL-1β) and antioxidant indices (T-SOD, GSH, and CAT). Above all, both S-LA and R-LA can alleviate the inflammation and oxidative damage caused by oxidative stress in aged laying hens, and R-LA is more effective than S-LA. Thus, these findings will provide basic data for the potential development of α-lipoic acid as a chiral dietary additive for laying hens.
... Using of LA with AgNPs improved the serum male sex hormones. This result was correlated with Othman et al. (2012) who revealed that lipoic acid kept cholesterol and sex hormone-binding globulin (SHBG) levels as that of controls. These results could be attributable to LA's antioxidant activity, which improves the signal transduction pathways required for optimal hypothLAmus-testicular axis function, resulting in normal testosterone release and sperm generation. ...
Article
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Silver nanoparticles (AgNPs) are commonly utilized in medicine. However, they have negative effects on the majority of organs, including the reproductive system. AgNPs were reported to be able to reach the testicular tissues due to their nano size, which allows them to pass through blood-testicular barriers. The goal of this study was to see if alpha-lipoic acid (LA) or Ginkgo biloba (GB) might protect adult rat testes after intraperitoneal injection of AgNPs. Forty male healthy adult Wister albino rats were randomly assigned to four groups: control, AgNPs-intoxicated group intraperitoneally injected AgNPs 50 mg/kg b.w, 3 times a week; LA + AgNPs group intoxicated with AgNPs and orally gavaged with 100 mg LA/kg b.w; and GB + AgNPs group injected with AgNPs and orally given GB extract 120 mg/kg b.w for 30 consecutive days. Biochemical changes (testosterone, ACP, and prostatic acid phosphatase), oxidative indices, mRNA expression of proapoptotic (BAX) and anti-apoptotic (BCL-2) biomarkers, histological, and immunohistochemical changes in testicular tissues were investigated. Significant decrease in serum testosterone level and elevation in ACP and PACP enzyme activity in AgNPs-treated rats. As well, there were lowering in tGSH, GSH GR, GPx, and elevation in MDA and GSSG values. AgNPs-exposed rats expressed downregulation of testicular thirodexin-1 (Txn-1), transforming growth factor-1β (TGF-1β), anti-apoptotic (BCL-2), and upregulaion of proapoptotic biomarkers (BAX) mRNA expressions. Strong positive action to BAX and lowering the action of Ki-67 antibody were observed. Because of their antioxidant, anti-inflammatory, and anti-apoptotic properties, cotreatment with LA or GB could be beneficial in reducing the harmful effects of AgNPs on the testicles.
... This may be the anti-estrogenic potency of TCS which is worthy of further studies. Exposure to 4-tOP has been shown to produce adverse effects on reproduction, alteration of the sex ratio and development (Othman et al. 2012). An example of the adverse effect of estrogenic compounds including alkylphenol (4-tOP) on reproduction dated back in 1978 which produced feminization of fish in the English rivers reported by Sumpter and Johnson (2008). ...
Article
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4-tert-Octylphenol (4-tOP) and triclosan (TCS) are endocrine disruptors which have been detected in environmental matrices such as air, soil and water at ultra-low levels. Exposure to endocrine disruptors may account at least in part, for the global increase in the incidence of non-communicable diseases like cancers and diabetes and may also lead to an imbalance in the aquatic ecosystem. River Buffalo is an important natural resource in the Eastern Cape of South Africa serving more than half a million people. The presence of the two compounds in the river water hitherto unknown was investigated during winter seasons using solid-phase extraction and gas chromatography–mass spectrometric techniques. The sampling points differed by some physicochemical parameters. The concentration of 4-tOP ranged 0–755 ng/L, median value 88.1 ng/L while that of TCS ranged 0–1264.2 ng/L and the median value was 82.1 ng/L. Hazard quotient as an index of exposure risk varied according to daphnids ˃ fish ˃ algae for 4-tOP exposure while HQ for TCS exposure was algae > daphnids = fish showing that both compounds were capable of causing imbalance in the aquatic ecosystem. Graphical abstract
... Group 4, the LA/irradiated group, the rats in this group were supplemented with LA (50 mg/kg B.W., P.O), and then exposed on the 7th day of the treatment to whole-body irradiation after 1-h of LA administration. The dose selection and the time regimen for LA were decided based on previously published experimental studies which investigated the protective effects of LA against reproductive toxicity (Othman et al., 2012;Zhang et al., 2018). We chose the 4-day interval after radiation for the formation of maximum testicular damage in the irradiated groups as previously reported (Jiang et al., 2013;Said et al., 2019), and in the same time give a chance for the ameliorative/protective effect of LA, if present, to be manifested. ...
Article
Radiotherapy is one of the principal approaches employed in the treatment of pelvic cancers. Nevertheless, testicular dysfunction and infertility are among the most common adverse effects in young adult cancer survivors. Clinically, alpha-lipoic acid (LA) has been applied to improve the quality of sperm with a satisfactory effect. Therefore, the present study investigated the underlying mechanisms of the radioprotective effects of LA against testicular damage. Male Sprague-Dawley rats were exposed to 10 Gy of whole-body ϒ-radiation and LA (50 mg/kg, P.O.) was administered one week before and three days post-irradiation. LA showed remarkable capacity in preserving testicular tissue against radiation damage by improving histological and ultrastructural changes of disorganized seminiferous tubules, besides enhancing its diameter, germinal epithelial thickness, and Johnsen’s score. Radiation instigated a significant decrease in sperm quality and quantity associated with depletion of serum testosterone levels, while the LA administration maintained spermatogenesis. Strikingly, LA exhibited antioxidant properties by restoring reduced glutathione levels and antioxidant enzyme activities such as catalase and glutathione-s-transferase, besides diminishing malondialdehyde levels in the testis of irradiated group. Furthermore, LA alleviated testicular inflammation through downregulation of nuclear factor-ĸB (NF-ĸB) expression with a subsequent reduction in interleukin (IL)-6 and cyclooxygenase-2 expression, accompanied by the augmented expression of the anti-inflammatory cytokine IL-10. Additionally, testicular fibrosis markers including Masson's trichrome and transforming growth factor (TGF)-β expression were noticeably declined in LA-treated irradiated rats, together with the upregulation of peroxisome proliferator-activated receptor-ϒ expression. Collectively, LA ameliorates radiation-mediated spermatogenesis-defects and testicular-damage via suppression of oxidative stress/NF-ĸB/TGF-β signaling.
... Moreover, it is a known EDC with estrogenic effects (Nimrod and Benson 1996). Multiple studies have demonstrated the impact of 4-OP on the reproductive systems of various species such as frog (Li et al. 2016), swine (Gral en et al. 2012), fish (Rey V azquez et al. 2009;Genovese et al. 2011), and rodents (Othman et al. 2012;Jambor et al. 2018). ...
Article
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The reproductive toxicity of 4-octylphenol (4-OP) has been studied in animals such as mouse and fish. In humans, the exposure of sperm to 4-OP has been shown to decrease motility and viability. In this study, we performed an in vitro assessment of the toxic effects of 4-OP on mouse TM4 Sertoli cells and investigated the underlying molecular mechanisms. TM4 cells were treated with four concentrations (0, 10, 30, and 50 µM) of 4-OP at the following time points: 24, 48, and 72 h. Cell viability and apoptosis assays were conducted following 4-OP exposure. We found that 4-OP significantly decreased cell viability in a concentration- and time-dependent manner, and increased apoptosis. Quantitative PCR analysis showed that the mRNA expression levels of BCL2 Associated X, Apoptosis Regulator (Bax) and BCL2 Antagonist/Killer (Bak) increased while that of BCL2 Apoptosis Regulator (Bcl-2) decreased in 4-OP–exposed cells compared with that in the controls. Western blotting revealed that 4-OP induced caspase-3 activity and Bad phosphorylation in a concentration- and time-dependent manner. Additionally, cytochrome C protein did not colocalize with mitochondrial marker dye by 24 h. Cytochrome c protein expression increased in a time-dependent manner upon exposure to 50 µM 4-OP. These results suggest that 4-OP induces mitochondria-mediated apoptosis through regulation of Bcl-2 family proteins and caspase-3 activation in male Sertoli cells.
... Moreover, ALA also facilitates interaction with other antioxidants and enhances their function; addition of ALA helps directly in the increased production of vitamin C, glutathione and coenzyme q10 upto 70% (Kleinkauf et al., 2013). Alpha lipoic acid has been shown to minimize oxidative stress induced by ROS, prevent sperm plasma membrane damage, inhibit lipid peroxidation (Huiming et al., 2011) and protect testosterone synthesis pathway across hypothalamo-pituitary-testicular axis (Othman et al., 2012). ...
Article
Aim of the present study was to monitor pre-freeze and post-thaw semen quality of Sahiwal bulls after addition of different concentrations of alpha lipoic acid (ALA) to the extender. Semen of four Sahiwal bulls was collected two times per week for four weeks with an artificial vagina. Ejaculates collected on each collection day from four bulls were pooled, split into four equal parts and diluted with tris-egg yolk-citrate-glycerol extender containing 0.500, 0.250, 0.125 and 0.000 mM (control) ALA. Diluted samples were filled in 0.5 ml straws, frozen and stored for at least 24 hours in liquid nitrogen. Pre-freeze and post-thaw quality was assessed in terms of sperm motility, plasma membrane integrity, live sperm percentage and acrosome integrity. Results indicated higher (P<0.05) mean values for pre-freeze and post-thaw sperm motility, plasma membrane integrity, live sperm percentage and acrosome integrity for samples diluted in extender having 0.250 and 0.125 mM ALA compared to samples diluted in extender containing 0.500 mM ALA and control extender. Moreover, higher mean values (P<0.05) of these characteristics were observed in samples diluted in extender containing 0.250 mM ALA compared to those diluted in extender containing 0.125 mM ALA. However, samples diluted with 0.500 mM ALA showed lower (P<0.05) pre-freeze and post-thaw semen quality than control samples. It was concluded that ALA at a concentration of 0.250 mM significantly improved pre-freeze and post-thaw characteristics of Sahiwal bull semen. However, field trials regarding effects of adding different concentrations of ALA to semen extender on fertility of frozen-thawed semen are necessary before making any recommendations in this regard.
... This may be the anti-estrogenic potency of TCS which is worthy of further studies. Exposure to 4-tOP has been shown to produce adverse effects on reproduction, alteration of the sex ratio and development (Othman et al. 2012). An example of the adverse effect of estrogenic compounds including alkylphenol (4-tOP) on reproduction dated back in 1978 which produced feminization of fish in the English rivers reported by Sumpter and Johnson (2008). ...
... Moreover, lipoic acid has ability to sustain the levels of protein thiols and modulate tissue endogenous antioxidants [18]. Based on these extraordinary properties, lipoic acid has been shown to be of interest as a therapeutic tool to protect the male reproductive health against a range of testicular toxicants in experimental animals, where oxidative stress is the part of underlying etiology [25,26,62,63]. Studies of the El-Maraghy and Nassar [64] reported that lipoic acid is as potent as the selenium in restoring the deteriorated testicular antioxidant status in rats exposed to the cadmium. ...
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The aim of this study was to evaluate the probable protective effect of α-lipoic acid against testicular toxicity in rats exposed to carbimazole during the embryonic period. Time-mated pregnant rats were exposed to carbimazole from the embryonic days 9 to 21. After completion of the gestation period, all the rats were allowed to deliver pups and weaned. At postnatal day 100, F1 male pups were assessed for the selected reproductive endpoints. Gestational exposure to carbimazole decreased the reproductive organ indices, testicular daily sperm count, epididymal sperm variables viz., sperm count, viable sperm, motile sperm and HOS-tail coiled sperms. Significant decrease in the activity levels of 3β- and 17β-hydroxysteroid dehydrogenases and expression of StAR mRNA levels with a significant increase in the total cholesterol levels were observed in the testis of experimental rats over the controls. These events were also accompanied by a significant reduction in the serum testosterone levels in CBZ exposed rats, indicating reduced steroidogenesis. In addition, the deterioration of the testicular architecture and reduced fertility ability were noticed in the carbimazole exposed rats. Significant reduction in the activity levels of superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione content with a significant increase in the levels of lipid peroxidation were observed in the testis of carbimazole exposed rats over the controls. Conversely, supplementation of α-lipoic acid (70mg/Kg bodyweight) ameliorated the male reproductive health in rats exposed to carbimazole during the embryonic period as evidenced by enhanced reproductive organ weights, selected sperm variables, testicular steroidogenesis, and testicular enzymatic and non-enzymatic antioxidants. To conclude, diminished testicular antioxidant balance associated with reduced spermatogenesis and steroidogenesis might be responsible for the suppressed reproduction in rats exposed to the carbimazole transplacentally. On the other hand, α-lipoic acid through its antioxidant and steroidogenic properties mitigated testicular toxicity which eventually restored the male reproductive health of carbimazole-exposed rats.
... Zum einen wurde bei Ratten nach kontinuierlicher Verabreichung von 25 mg 4-tert-Octylphenol/l Trinkwasser von der Konzeption bis zum Erwachsenenalter in Hepatozyten ein Anstieg an intrazellulärem Glykogen nachgewiesen (Hernández-Rodríguez et al. 2007). Zum anderen ergaben sich bei Ratten nach dreimal pro Woche, fünf Wochen lang erfolgter subkutaner Applikation eine verringerte Aktivität der Glukose-6-phosphat-Dehydrogenase im Hoden und auch ein verminderter Fruktosegehalt in der Samenflüssigkeit (Othman et al. 2012). Die durch 25 mg 4-tert-Octylphenol/kg KG im Gehirn von männlichen Ratten hervorgerufenen oxidativen Schädigungen wurden mit einer Induktion von reaktiven Sauerstoffspezies erklärt (Aydoğan et al. 2008). ...
Chapter
4‐tert‐Octylphenol The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated 4‐tert‐octylphenol to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints with the exception of developmental toxicity. Available unpublished study reports and publications are described in detail. 4‐tert‐Octylphenol is an endocrine‐active substance that might impair fertility. Despite appropriate investigations, no such effects and no influence on fertility were seen in a two‐generation feeding study in rats after doses of up to 250 mg/kg bw. In this study and in a 90‐day study, the most sensitive effect is delayed body weight development with NOAEL and LOAEL of 15 and 20 mg/kg bw and day, respectively. In a Draize test, 4‐tert‐octylphenol is a severe eye irritant. Because there are no inhalation studies investigating possibly irritating effects on the airways, bisphenol A, which is also a strong eye irritant, is used as a read‐across and a MAK value of 0.5 ml 4‐tert‐octylphenol/m ³ (4 mg/m ³ ) is thus established. The dose taken up at this concentration is clearly below the equipotent dose for 4‐tert‐octylphenol calculated from the human LOAEL for ethinylestradiol and 17β‐estradiol. Since the critical effect of 4‐tert‐octylphenol is local, Peak Limitation Category I is assigned. In analogy to bisphenol A, an excursion factor of 1 has been set. The substance is not genotoxic. Skin contact is not expected to lead to systemic toxicity or contact sensitization.
... In laboratory rats [2,3,9,11,12] and cultured mouse Leydig cells [13][14][15][16][17], oxidatively damaged Leydig cells and Leydig cells in aged testes experience suppression of antioxidant enzyme activities, reduced intracellular glutathione (GSH) content, accelerated lipid peroxidation and oxidative modification of DNA, and loss of the mitochondrial membrane potential required for testosterone synthesis. They exhibit reduced sensitivity to LH, fewer LH receptors expressed per cell, and impaired LH-induced activation of the steroidogenic acute regulatory protein (a component of a transmembrane multiprotein complex that catalyzes the import of cholesterol from the outer to the inner mitochondrial membrane, a rate-limiting step in steroid hormone synthesis [18]) [16,[19][20][21][22]. Additionally, the activities of several enzymes of the testosterone biosynthetic pathway (cytochrome P450 [CYP]11A1, 3b-hydroxysteroid dehydrogenase/D 5 /D 4 isomerase [3b-HSD; HSD3B2], CYP17A1 hydroxylase, CYP17 A1lyase, 17b-HSD; HSD17B3) are reduced and testosterone synthesis is inhibited in aging rats [2,3,12], oxidatively damaged rat testes [23], oxidatively damaged cultured mouse Leydig cells [14,24], and oxidatively stressed adult human testes [25]. ...
... Both abnormalities were efficiently prevented by co-administration with LA. Previous papers demonstrating the beneficial effect of LA administration in testis from rats receiving a mixture of the pesticides chloropyrifos and fenitrothion (Gawish, 2010) or the administration of 4-tert-octylphenol (Othman et al., 2012) reinforces the promising use of this antioxidant as a tool to prevent the histological damage induced by diverse pesticides. Since human life without pesticide exposure is practically inconceivable, the establishment of lower MRLs (Maximum Residues Levels) in food together with antioxidant supplementation of diet (especially those of an amphiphilic nature such as lipoate) remains a valid preventive strategy (Gonzá lez-Pé rez and Gonzá lez-Castaneda, 2006). ...
Article
We have previously demonstrated that the sub-chronic administration of low doses of Toc or α-Toc, glyphosate and zineb to rats (i.p. 1/250 LD50, three times a week for 5 weeks) provoked severe oxidative stress (OS) in testicles. These effects were also reflected in plasma. Lipoic acid (LA) and α-tocopherol are considered as antioxidants due to their ability to neutralize reactive oxygenated species (ROS) and reset endogenous antioxidant levels. To investigate the possible protective effect on reproductive function, LA and Toc (i.p. 25, 50 and 100mg/kg) were administered simultaneously with the pesticide mixture (PM) for 5 weeks. Both drugs prevented OS and the damage to proteins and lipids caused by PM in a dose-dependent manner. The PM-induced increase levels of prostaglandins E2 and F2α was completely restored by LA but not by Toc. Similarly, only LA was able to restore the inhibition of testosterone production, the decrease of 3β- and 17β-hydroxysteroid dehydrogenases activities, and the elevation of gonatropins (FSH and LH) levels produced by PM. Furthermore, LA was more efficient than Toc in normalizing the histological alterations produced by PM administration, suggesting that pesticides act though other mechanisms that generate oxidative stress. In our experimental model LA displayed a higher protective role against pesticide-induced damage than that observed by Toc administration. Our results suggest that LA administration is a promising therapeutic strategy for coping with disorders suspected to be caused by OS generators - such as pesticides - in male reproductive system.
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Aims Cytarabine (CYT), a prevalent anticancer drug for blood cancers, detrimentally affects male reproductive development and function. Alpha-lipoic acid (ALA), a universal antioxidant, offers defense against chemical-induced reproductive dysfunction. Our study sought to explore ALA's protective role against prenatal CYT-induced reproductive impairment in F1 male adult rats. Main methods Pregnant rats were divided into 5 groups and administered normal saline, ALA 200 mg/kg, CYT 12.5 mg/kg, CYT 25 mg/kg, and CYT 25 mg/kg + ALA 200 mg/ kg from gestational day 8 to 21. On postnatal day 73, F1 male rats were sacrificed, and general, oxidative, steroidogenic, spermatogenic, histological, and morphometrical parameters were evaluated. Key findings Prenatal CYT caused dose-dependent reductions in body weight, testis, and accessory gland weights; elevated oxidative stress; delayed puberty onset; sperm anomalies (decreased count, motility, viability, seminal fructose; increased morphological anomalies); impeded steroidogenesis (lower testosterone, follicle-stimulating hormone, luteinizing hormone, 3β-Hydroxysteroid dehydrogenase(HSD), 17β-HSD, and elevated cholesterol); and testicular histopathological and morphometric disturbances. Maternal supplementation of ALA was found to alleviate all the CYT-induced reproductive disruptions. Significance The present work accentuates the beneficial actions of ALA against CYT-induced impairment in reproductive development and functions by combating disruptions in oxidative balance, steroidogenesis, spermatogenesis, and testicular histological aberrations. However, future experimental and clinical studies are warranted to explore the molecular mechanisms involved in the ALA’s protection against prenatal CYT-induced testicular injury. Graphical Abstract
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Silver nanoparticles (AgNPs) are more commonly utilised in medicine, however they have negative effects on the majority of organs, including the reproductive system. AgNPs were reported to be able to reach the testes due to their small size, which allows them to pass through blood testicular barriers. The goal of this study was to see if LA (alpha lipoic acid) or GB (ginkgo biloba) might protect adult rat testes after intraperitoneal injection of AgNPs. Forty male healthy adult Wister albino rats were randomly assigned to four groups (10 rats each); control, AgNPs-intoxicated group intraperitoneally injected AgNPs 50 mg/kg b.w, 3 times a week, LA + AgNPs group intoxicated with AgNPs and orally gavaged with 100 mg LA/kg b.w, and GB + AgNPs group injected with AgNPs and orally given GB extract 120 mg/kg b.w were continued for 30 consecutive days. Biochemical changes in testicular tissue (testosterone, ACP, and Prostatic acid phosphatase), oxidative indices in testicles tissues, mRNA expression of pro-apoptotic (BAX) and anti-apoptotic (BCL-2) biomarkers, histological, and immunohistochemical changes were studied. Significant decrease in serum testosterone level and elevation in ACP and PACP enzyme activity in AgNPs treated group than in the control. In addition, lowering in tGSH, GSH GR, GPx and elevation MDA and GSSG were observed in AgNPs treated group than control. Decreasing in mRNA expression thirodexin-1 (Txn-1), transforming growth factor-1β (TGF-1β), anti-apoptic (BCL-2) and elevation the expression of proapoptic biomarkers (BAX) in the testis homogenates of rats exposed to silver nanoparticles. Strong positive action to BAX and lowering the action of Ki-67antibody were observed. Because of their antioxidant, anti-inflammatory, and anti-apoptotic properties, co-treatment with LA or GB may be beneficial in reducing the harmful effects of AgNPs on the testicles.
Article
In this systematic review, we assessed different studies to evaluate the protective effect of alpha-lipoic acid (ALA), as a multifaceted antioxidant, on sperm functions in rodent models. Four databases were searched to find papers reporting the effect of ALA treatment on animal models of male infertility. Up to December 2022, 11,787 articles were identified to explain the ALA protective effects. The included studies were evaluated for eligibility and risk of bias (CRD42022341370). Finally, we identified 23 studies that explain the effect of ALA on sperm functions in rodents. Among them, 15 studies indicated that ALA could restore sperm parameters. Six studies showed a significant reduction in sperm DNA damage by ALA treatment. Seventeen papers displayed the ALA antioxidant ability, and four studies indicated the ALA anti-inflammatory effect. Besides, thirteen studies displayed that ALA could modulate androgenesis. Also, eighteen studies revealed that ALA restored the testicular architecture to normal, and was also effective in restoring reproductive performance in two included studies. This systematic review provided cogent evidence for the protective effect of ALA in rodent models for male infertility by re-establishing spermatogenesis and steroidogenesis and maintaining redox and immune systems homeostasis.
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In the present study, responses of the Chinese brown frog (Rana chensinensis) to exposure to different doses and duration of Octyphenol (OP) which degraded from alkylphenol ethoxylates (APEs) were characterized during the adult periods. The effects of OP on growth, development and reproduction and the expression of genes in gonad were investigated. The expression levels of fshβ, lhβ, fshr and lhr had significant differences as the exposure time increased. The pathological and morphological changes were also observed in the OP treatments. Furthermore, the number of TUNEL positive cells and the TUNEL index was elevated after exposed to OP. Besides that, OP treatment could influence its mating behavior and reduce the fertilization rates. Taken together, these results indicated that OP disrupt sex steroid signaling, normal development of spermatogenesis, courtship behavior of male frogs and decline fertilization rate in R. chensinensis.
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In the study, the ameliorating effects of alfa lipoic acid (ALA) against doxorubicin-induced testicular apoptosis, oxidative stress and disrupted mitochondrial fusion were investigated in male rats. Rats were divided into four groups as control, doxorubicin (DOX), DOX + ALA and ALA. A single dose of 15 mg/kg DOX was administered i.p to the DOX and DOX + ALA groups. 50 mg/kg ALA was given to the DOX + ALA and ALA groups by oral gavage every other day. After 28 days, rat testes and serum samples were collected and analysed. Administration of DOX alone caused a decrease in body and relative testicular weights, seminiferous tubule diameter and germinal epithelium thickness, Johnsen's score and serum testosterone levels. DOX treatment led to severe testicular damage such as tubular degeneration, and atrophic tubules. Also, the activities of superoxide dismutase and glutathione peroxidase were reduced, while the level of malondialdehyde was increased in the testis. The mRNA levels of apoptotic-related genes (CASP3, TP53, BAX, BCL2) and apoptotic index were increased, while mitofusin-2 decreased. DOX caused an increase in CASP3 and a decrease in mitofusin-2 immunoreactivities. Treatment with ALA markedly improved all of DOX-induced biochemical, histochemical and molecular alterations in rat testis. Consequently, ALA has a therapeutic role in ameliorating DOX-induced testicular damage in rats.
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Research question Does supplementation with Alpha-lipoic acid (ALA) enhance sperm parameters and/or the status of sperm lipid peroxidation and DNA fragmentation in microsurgically-repaired varicocele individuals? Design Individuals with varicocele undergone varicocelectomy were divided into two groups receiving 600mg of ALA or the identical placebo for 80 days. Semen analyses of the participants retrieved before the surgery and after completion of the medication course were compared. Participants, clinicians, and the data analysts were blinded to the randomization sequence. Results In ALA group, level of sperm total (p=0.01) and progressive motility (p=0.002) were significantly higher after the surgery. Regarding DNA damage, sperm chromatin structure assay results showed significant decrease in ALA group (p=0.003). Conclusion(s) An 80-day course of ALA medication after the surgery, improves semen quality in individuals with varicocele.
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As known for different metabolic functions, α-lipoic acid (ALA) has been tested for spermatozoa preservation of animals as well as of human, but not for fish spermatozoa. The present study determined the effects of ALA on short and long-term (cryopreservation) preservation of common carp (Cyprinus carpio) spermatozoa, for the first time. For that, spermatozoa were diluted in extenders containing 0 (control), 0.025, 0.05, 0.1, 0.5, 1, 2, 5, and 10 mM of ALA concentrations in both short-term preservation and cryopreservation. Spermatozoa motility parameters by computer-assisted semen analysis, viability, lipid peroxidation and catalase activity in spermatozoa were conducted in both 2nd and 120th hours of short-term storage and post-thaw samples. Higher percentages of total spermatozoa motility (80 ± 3) and viability (87 ± 3) were observed in 0.5 mM ALA group after 120 h of incubation. In post-thaw samples, higher percentages of these parameters were in 1 mM ALA group (74 ± 3 and 83 ± 2, respectively). Moreover, the results have shown that the addition of ALA until concentrations of 2 mM improved especially spermatozoa curvilinear velocity, maintained viability, and suppressed excessive lipid peroxidation during the preservations. In conclusion, the additions of 0.5 mM ALA for short-term preservation and 1 mM ALA for cryopreservation were the optimal concentrations, and shown the protective effects on common carp spermatozoa, when considering all measured parameters together.
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Octylphenol (OP) is a widely distributed endocrine disrupting chemical (EDC), and can be commonly found in various and diverse environmental media. Previous studies have reported that OP exposure could cause many adverse effects on aquatic animals. However, knowledge concerning the impact of OP on lipid metabolism in amphibians was still limited. In our study, Rana chensinensis tadpoles were exposed to different OP concentrations (0, 10⁻⁸, 10⁻⁷ and 10⁻⁶ mol/L) from the Gosner stage (Gs) 25–38. The RNA-seq analysis of tadpole intestines was explored by RNA-seq, and six differentially expressed genes (DEGs) related to the fat digestion and absorption were validated by RT-qPCR. Moreover, we used 16s amplicon sequencing to evaluate effects of OP on intestinal microbiome in tadpoles, further determining the variations of lipid metabolism. Our results revealed that OP exposure influenced gene expression levels related to fat digestion and absorption and led to alteration of structure and composition of intestinal microbiome. At the phylum level, the Firmicutes/Bacteroidetes ratio was gradually decreased in OP exposure groups, which disrupted lipid metabolism. According to the results of intestinal microbial functional prediction, OP exposure interfered with metabolic function and increased risk of disease. These data provide us with powerful resources to assess the effects of OP on lipid metabolism by integrating RNAseq and 16s amplicon sequencing analysis of intestinal tract and intestinal microbiome.
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The toxic effects of 4-octylphenol (4-OP) have been studied in species such as mouse and fish; however, the toxic effects of 4-OP in male specific niche cells has not been researched. In this study, we investigated the molecular mechanism of toxicity of 4-OP in mouse TM4 Sertoli cells. TM4 cells were treated with four concentrations (0, 10, 30, and 50 µM/mL) of 4-OP at time points 24, 48, and 72 h. Cell viability and apoptosis assay was conducted following exposure. 4-OP significantly decreased cell viability in a concentration- and time-dependent manner, and increased apoptosis. Quantitative PCR analysis showed that Bad, Bax, and Bak mRNA expression levels were higher in exposed cells than in the control, but Bcl-2 expression was decreased. Western blotting revealed that 4-OP induced activities of caspase-3 and phosphorylation of Bad in a concentration- and time-dependent manner. Additionally, cytochrome C protein did not colocalize with mitochondria marker dye by 24 h. Cytochrome c protein expression increased in a time-dependent manner with 50 µM/mL. These results suggest that 4-OP induces mitochondria-mediated apoptosis by regulation of Bcl-2 family proteins and caspase-3 activation in male Sertoli cells.
Article
The endocrine-disrupting chemical 4-tert-octylphenol (OP) can mimic estrogen and testosterone hormones and threaten health; fertaric acid (FA) is a hydroxycinnamic acid found in grapefruit. This study aimed to investigate whether FA has a protective effect on 4-tert-octylphenol–related hepatotoxicity. Thirty male albino rats were divided into 5 equal groups of 6 rats each as follows: control group—administrated orally with 1 ml saline 3 days/week for 4 weeks; corn oil group—administrated orally with 1 ml corn oil 3 days/week for 4 weeks; FA-treated group—administrated orally with FA (45 mg /kg body weight) dissolved in saline 3 days/week for 4 weeks; OP-treated group—administrated orally with OP (40 mg /kg body weight) dissolved in corn oil 3 days/week for 4 weeks; FA + OP–treated group—administrated orally with FA (45 mg /kg body weight) dissolved in saline 3 days/week for 4 weeks then administrated orally with OP (40 mg/kg body weight) dissolved in corn oil 3 days/week for another 4 weeks. The results obtained showed that OP-exposed rats had significant increase in serum aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase, lactate dehydrogenase, bilirubin, serum and liver tumor necrosis factor-α, interleukin-1β and malondialdehyde, serum interleukin-6 and interleukin-10 and significant decrease in serum alkaline phosphatase, acid phosphatase, serum and liver superoxide dismutase, glutathione peroxidase, and catalase. OP caused an inhibitory action on the gene expression of liver proteins. Rats treated with FA before OP exposure had near-normal values. In addition, FA prevented the degradation of liver deoxyribonucleic acid (DNA), and DNA reformation occurred. In conclusion, FA protects from dangerous OP-related hepatic effects, and these results were supported by molecular and histological investigations.
Article
The present study evaluates the protective effect of α-lipoic acid (LA) against arsenic-induced testicular and epididymal oxidative damage in rats. Arsenic caused significant reduction in the reproductive organ weights, serum testosterone levels, testicular daily sperm count, epididymal sperm count, sperm motility, sperm viability, and sperm membrane integrity. Significant reduction in the activity levels of superoxide dismutase, catalase, and glutathione levels with a concomitant increase in the lipid peroxidation and protein carbonyl content in the testis and the cauda epididymis of arsenic-exposed rats. Arsenic intoxication also enhanced the testicular caspase-3 mRNA levels, disorganization of testicular and cauda epididymal architecture as well as increased arsenic content in the testis and the cauda epididymis of rats. Arsenic exposure also deteriorated fertility ability in male rats over controls. Conversely, α-LA negated the testicular and cauda epididymal oxidative stress and restored the male reproductive health in arsenic-exposed rats.
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Globally, the third cause of males cancer and the fourth cause of females cancer is colon cancer (CC). In Egypt, high CC percentage occurs in children and in individuals below 40 years of age. The complete loss of biological enzyme function is the main cause of CC and consequently CC increased in smoking and pollution exposure. The aim of this review is to focus on the application of metabolome as a physiological tool that can play an important role in preventing CC incidence by natural products and hormones. The dietary factors, intestinal micro-flora and endogenously produced metabolites are the main three causes that produce free radicals in the colon. A correlation occurs between the enzyme activity and CC polymorphisms or property. Nowadays metabolome is applied with the progress of different analytical methods, data bases and tools for cancer predication and stimulation especially in CC cases. Metabolism is defined as intracellular chemical reactions that produce chemical substances and energies sustaining life. Metabolic pathway networks are also composed of links that are defined as transformation of chemical structures between two metabolites and an enzyme reaction. The most important advantage of metabolome is its ability to analyze metabolites from any source, regardless of origin, where the application of liquid chromatography combined with mass spectra in metabolome analysis to a series of cancer cell lines that were progressively more tumorigenic due to the induction of 1,2,3 or 4 oncogenes to cell lines could be a metabolome example application. In conclusion, natural products and hormones are very important in preventing CC in humans and animal models where both natural products and hormones play a significant and important effect in regulating physiological process especially in CC cases. In this situation, metabolome must increase in its application in the future for the diagnosis of CC cases.
Article
4-tert-octylphenol (OP) is an endocrine-disrupting chemical that causes harmful effects to human health. Chlorogenic acid is the major dietary polyphenol present in various foods and beverages. The aim of the present study was to evaluate the protective role of chlorogenic acid in anemia and mineral disturbance occurring in OP toxicity in rats. Thirty-two male albino rats were divided into four equal groups (8 rats/group) as follows. The first (control) group was treated daily with an oral dose of 1 ml saline for two weeks. The second group was treated daily with an oral dose of 60 mg chlorogenic acid/kg body weight for two weeks. The third and fourth groups received daily intraperitoneal (ip) injections with 100 mg OP/kg body weight for two weeks; the fourth group was treated daily with an oral dose of 60 mg chlorogenic acid/kg body weight for three weeks starting one week before OP injections. The results revealed that OP induced significant decreases in hemoglobin, hematocrit, red blood cells, mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration, platelet count, white blood cells, lymphocyte and neutrophil percent, transferrin receptor, serum calcium, phosphorous, sodium, potassium, chloride, glutathione-S-transferase, glutathione peroxidase, catalase, glutathione reductase, and superoxide dismutase. Moreover, significant increases in serum hepcidin, ferritin, transferrin, erythropoietin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea, creatinine, selenium, zinc, manganese, copper, iron, malondialdehyde, and protein carbonyl levels were found in OP groups. OP exposure also induced cell apoptosis. Chlorogenic acid pretreatment in OP-treated groups restored all the mentioned parameters to approach the normal values. In conclusion, chlorogenic acid protects from anemia and mineral disturbances in 4-tert-octylphenol toxicity by ameliorating oxidative stress and apoptosis.
Article
It has been proposed that a decline in sperm quality is associated with exposure to environmental chemicals with estrogenic activity. Seeking possible explanations for this effect, this study investigated the effects of octylphenol (OP) on the synthesis of steroid hormones in amphibian. Rana chensinensis were exposed to 10(-8), 10(-7) and 10(-6)mol/L OP after 10, 20, 30 and 40 days. The cDNA fragments of StAR (274bp), CYP17 (303bp) and CYP19 (322bp) were cloned. In situ hybridization and immunohistochemistry revealed that positive signals of StAR, CYP17, CYP19 mRNA and proteins mainly in the Leydig cells of testes. Real-time PCR showed that up-regulation of StAR and CYP19, and down-regulation of CYP17 after exposure to 10(-8), 10(-7) and 10(-6)mol/L OP. The results suggest that OP can alter transcriptions of StAR, CYP17 and CYP19, thus disturb the expressions of StAR, P450c17 and P450arom, thereby adversely affect steroid synthesis.
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Sperm survival depending upon integral membranes and function is imperative for fertilization. This study was designed to augment survival of buffalo spermatozoa using alpha-lipoic acid (ALA) and cholesterol-loaded cyclodextrin (CLC) during cryopreservation. Semen was frozen using 0, 0.5, 1, 1.5, 2 and 2.5 mmol L−1 ALA (experiment 1) and ALA or CLC separately or together (experiment 2). Semen was assessed for post-thaw motility, plasma membrane integrity (PMI), intact acrosome and plasma membrane (IACR-IPM) and DNA integrity at 0, 1.5, 3 and 4.5 hr of incubation. In experiment 1, use of 0.5 mmol L−1 ALA enhanced the sperm cryosurvival and post-thaw longevity than other groups up to 4.5 hr of incubation, and this concentration of ALA was used in second experiment with CLC. The results revealed higher (p < .05) sperm survival function and time of sperm attributes due to use of ALA than CLC and control. However, the sperm quality did not improve (p > .05) when ALA was combined with CLC. In conclusion, survival of buffalo bull spermatozoa during freeze-thawing and post-thaw incubation can be enhanced more with ALA than CLC or control, followed by CLC than control. However, there is no synergistic effect on survival of buffalo bull spermatozoa due to ALA and CLC.
Article
Alkylphenols such as 4-tert-octylphenol (OP), nonylphenol, and bisphenol A are classified as endocrine-disrupting chemicals (EDCs). Digestion and metabolism of food are controlled by many endocrine factors, including insulin, glucagon, and estrogen. These factors are differentially regulated during pregnancy. The alteration of nutritional intake and fat metabolism may affect the maintenance of pregnancy and supplementation of nutrients to the fetus, and therefore can cause severe metabolic diseases such as ketosis, marasmus and diabetes mellitus in pregnant individuals. In this study, we examined the effects of OP on fat metabolism in pregnant rats. Ethinyl estradiol (EE) was also administered as an estrogenic positive control. In our results, rats treated with OP showed significantly reduced body weights compared to the control group. In addition, histological analysis showed that the amount of fat deposited in adipocytes was reduced by OP treatment. To study the mechanism of action of OP in fat metabolism, we examined the expression levels of fat metabolism-associated genes in rat adipose tissue and liver by real-time PCR. OP and EE negatively regulated the expression of lipogenic enzymes, including FAS (fatty acid synthase), ACC-1 (acetyl-CoA carboxylase-1), and SCD-1 (stearoyl-CoA desaturase-1). The levels of lipogenic enzyme-associated transcription factors such as C/EBP-α (CAAT enhancer binding protein alpha) and SREBP-1c (sterol regulatory element binding protein-1c) were also reduced in both liver and adipose tissue. In summary, these findings suggest that OP has adverse effects on fat metabolism in pregnant rats and inhibits fat deposition via regulating lipogenic genes in the liver and adipose tissue. The altered fat metabolism by OP may affect the nutrition balance during pregnancy and can cause metabolism-related diseases. Copyright © 2015 Elsevier B.V. All rights reserved.
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The current investigation was carried out to clarify whether the addition of antioxidant Alpha Lipoic Acid (ALA) increases the quality of cryopreserved Nili Ravi buffalo semen. Semen from five healthy Nili-Ravi buffalo bulls was collected by artificial vagina and subjected to the different inclusion levels of ALA @ 0.5mM, 1.mM, 2.mM, 3.mM, and 4.mM respectively. Experiments were executed for Post thawed semen analysis including spermatozoa motility, viability, plasma membrane integrity and acrosomal integrity. Our result indicated that Spermatozoa motility and viability was significantly higher (P < 0.05) at lower amount of alpha lipoic acid at 0.5 and 1.mM whereas the spermatozoa acrosomal integrity was significantly higher (P < 0.05) at 0.5mM. On the other hand, the lowest spermatozoa acrosomal integrity was observed with increasing concentration of alpha lipoic acid at 2.0, 3.0 and 4.mM. Our result further demonstrated that plasma membrane integrity was higher at 0.5 mM (P < 0.05). Based on the finding of current study, it is evident that the Antioxidant Alpha Lipoic Acid could be used for enhancing quality of the post thawed buffalo spermatozoa at lower concentration (0.5mM).
Article
Octylphenol (OP) is one of ubiquitous pollutants in the environment. It belongs to endocrine-disrupting chemicals (EDC). It is used in many industrial and agricultural products. Pectin is a family of complex polysaccharides that function as a hydrating agent and cementing material for the cellulose network. The aim of this study was to evaluate the therapeutic effect of pectin in kidney dysfunction, oxidative stress and apoptosis induced by OP exposure. Thirty-two male albino rats were divided into four equal groups; group 1 control was injected intraperitoneally (i.p) with saline [1 ml/kg body weight (bwt)], groups 2, 3 & 4 were injected i.p with OP (50 mg/kg bwt) three days/week over two weeks period where groups 3 & 4 were injected i.p with pectin (25 or 50 mg/kg bwt) three days/week over three weeks period. The results of the present study revealed that OP significantly decreased glutathione-S-transferase (GST), glutathione peroxidase (GPx), catalase (CAT), reduced glutathione (GSH), glutathione reductase (GR) and superoxide dismutase (SOD) levels while increased significantly lipid peroxidation (MDA), nitric oxide (NO) and protein carbonyls (PC) levels in the kidney tissues. On the other hand, OP increased serum urea and creatinine. Furthermore, OP increased significantly serum uric acid but decreased significantly the kidney weight. Moreover, OP decreased p53 expression while increased bcl-2 expression in the kidney tissue. The treatment with either dose of pectin to OP-exposed rats restores all the above parameters to approach the normal values where pectin at higher dose was more effective than lower one. These results were supported by histopathological investigations. In conclusion, pectin has antioxidant and anti-apoptotic activities in kidney toxicity induced by OP and the effect was dose-dependent.
Article
We examined the effects of estradiol (E2), 4-tert-octylphenol (OP), and bisphenol A (BPA) on uterine contractions in immature rats. The expression and localization of contraction-associated proteins (CAPs), and contractility of rat uterus with a collagen gel contraction assay were analyzed. E2, OP, and BPA all increased oxytocin (OT)-related pathway, while the prostaglandin-related signaling was reduced. Interestingly, E2 and estrogenic compounds showed distinct effects on the contractile activity of uterine cells. E2 enhanced the contractility, while OP and BPA significantly decreased it. Immuohistochemical analysis of CAPs showed distinct regulation of prostaglandin F receptor localization by E2 and estrogenic compounds, which may explain the different contractile activities of those reagents. In summary, we demonstrate that E2, OP, and BPA regulate CAP expression in a similar manner in the immature rat uterus, however, the effects on contractile activity were modulated differently. These findings suggest that OP and BPA interfere with uterine contractility.
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The development of nontoxic but effective radioprotectors is needed because of the increasing risk of human exposure to ionizing radiation. We have reported that α-lipoic acid confers considerable radio-protective effect in mouse tissues when given prior to x-irradiation. In the present study, α-lipoic acid supplementation prior to x-irradiation with 4 and 6 Gy significantly inhibited the radiation-induced decline in total antioxidant capacity (TAC) of plasma. Radiation-induced decline in non-protein sulfhydryl content (NPSH) of different tissues, namely, brain, liver, spleen, kidney, and testis, was also ameliorated significantly at both 4 and 6 Gy doses. Maximal augmentation of radiation-induced protein carbonyl content was observed in spleen followed by brain, kidney, testis, and liver. Maximal protection in terms of carbonyl content was observed in spleen (116%) at 6 Gy dose, and minimal protection was found in liver (22.94%) at 4 Gy dose. Maximal increase in MDA (malondialdehyde) content was observed in brain, followed by testis, spleen, kidney, and liver. Protection by α-lipoic acid pretreatment in terms of MDA content was maximal in brain (51.67%) and minimal in spleen. The findings support the idea that α-lipoic acid is a free-radical scavenger and a potent antioxidant.
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The purpose of this study was to investigate whether bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) induce oxidative stress in the liver of male rats and co-administration of vitamin C can prevent any possible oxidative stress. Wistar male rats were divided into seven groups (vehicle, BPA, NP, OP, BPA+C, NP+C, OP+C). BPA, OP and NP groups (25 mg kg(-1)day(-1)) were administered orally to rats three times a week for 50 days. In BPA+C, NP+C, OP+C groups, vitamin C (60 mg kg(-1)day(-1)) was administered along with BPA, OP and NP (25 mg kg(-1)day(-1)) treatments. Aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), thiobarbituric acid-reactive substances (TBARS) were increased, glutathione (GSH) levels were decreased in treatment groups. AST, ALT, LDH and TBARS levels were increased whereas GSH levels were decreased in BPA+C, NP+C and OP+C groups compared to BPA, NP, and OP groups, respectively. Hepatic necrosis and congestion were observed in livers of rats treated. In conclusion, the present results demonstrate that BPA, NP, and OP cause oxidative damage by disturbing the balance between ROS and antioxidant defenses system in liver of male rats. Vitamin C co-administration along with BPA, NP, OP aggravates the damage in liver of male rats.
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Abstract The present study was undertaken to investigate the ability of dietary supplements to reduce the formation and severity of cataracts in mice irradiated with high-energy protons or iron ions, which are important components of the radiation encountered by astronauts during space travel. The mice were exposed to proton or iron-ion radiation and fed with a control diet or diets supplemented with the soybean-derived protease inhibitor, Bowman-Birk inhibitor (BBI), in the form of BBI Concentrate (BBIC) or an antioxidant formulation [containing l-selenomethionine (SeM), N-acetyl cysteine (NAC), ascorbic acid, co-enzyme Q10, alpha-lipoic acid and vitamin E succinate] both before and after the radiation exposure. At approximately 2 years after the radiation exposure, the animals were killed humanely and lenses were harvested and characterized using an established classification system that assigns discrete scores based on the severity of the lens opacifications. The results showed that exposure to 1 GeV/nucleon proton (3 Gy) or iron-ion (50 cGy) radiation significantly increased the cataract prevalence and severity in CBA/J mice to levels above the baseline levels of age-induced cataract formation in this mouse strain. Treatment with BBIC or the antioxidant formulation significantly reduced the prevalence and severity of the lens opacifications in the mice exposed to iron-ion radiation. Treatment with BBIC or the antioxidant formulation also decreased the severity of the lens opacifications in the mice exposed to proton radiation; however, the decrease did not reach statistical significance. These results indicate that BBIC and the antioxidant formulation evaluated in this study could be useful for protecting astronauts against space radiation-induced cataracts during or after long-term manned space missions.
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Assisted reproductive techniques are useful in helping infertile couples achieve successful conception. Initial studies have shown that sperm cryopreservation, one step in assisted reproduction, causes a dramatic reduction in sperm quality. This has been attributed to, among other things, free radical activities. The aim of the present study was to minimize this oxidative attack by adding an antioxidant into the sperm microenvironment. Alpha lipoic acids were selected for this purpose for their efficient free radical scavenging properties and solubility in lipid and aqueous phases. For this investigation, semen from six Boer bucks was pooled. Seminal analysis of the baseline prior to incubation of samples with different concentrations of Alpha lipoic acids (0.00625, 0.0125, 0.025, 0.05, 0.1 mmol/ml) was performed, and post-seminal analysis was conducted after a one-hour incubation. The comet assay was used to observe the effect of Alpha lipoic acids on sperm DNA integrity. Statistical analysis using an unpaired t-test with a significance level of p<0.05 was then performed. Our results indicate that the sperm motility rate was improved after incubation with Alpha lipoic acids at a concentration of 0.02 mmol/ml. This concentration was also capable of reducing DNA damage. In conclusion, Alpha lipoic acids renders cryoprotection to sperm, thereby improving sperm quality.
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Thioctic acid (TA) and its reduced form dihydrolipoic acid (DHLA) have recently gained some recognition as useful biological antioxidants. In particular, the ability of DHLA to inhibit lipid peroxidation has been reported. In the present study, the effects of TA and DHLA on reactive oxygen species (ROS) generated in the aqueous phase have been investigated. Xanthine plus xanthine oxidase-generated superoxide radicals (O2-), detected by electron spin resonance spectroscopy (ESR) using DMPO as a spin trap, were eliminated by DHLA but not by TA. The sulfhydryl content of DHLA, measured using Ellman's reagent decreased subsequent to the incubation with xanthine plus xanthine oxidase confirming the interaction between DHLA and O2-. An increase of hydrogen peroxide concentration accompanied the reaction between DHLA and O2-, suggesting the reduction of O2- by DHLA. Competition of O2- with epinephrine allowed us to estimate a second order kinetic constant of the reaction between O2- and DHLA, which was found to be a 3.3 x 10(5) M-1 s-1. On the other hand, the DMPO signal of hydroxyl radicals (HO.) generated by Fenton's reagent were eliminated by both TA and DHLA. Inhibition of the Fenton reaction by TA was confirmed by a chemiluminescence measurement using luminol as a probe for HO.. There was no electron transfer from Fe2+ to TA or from DHLA to Fe3+ detected by measuring the Fe(2+)-phenanthroline complex. DHLA did not potentiate the DMPO signal of HO. indicating no prooxidant activity of DHLA. These results suggest that both TA and DHLA possess antioxidant properties. In particular, DHLA is very effective as shown by its dual capability by eliminating both O2- and HO..
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The relationship between Alzheimer disease (AD) and aging is not currently known. In this study, postmortem frontal- and occipital-pole brain samples were obtained from 16 subjects with AD, 8 age-matched controls, and 5 young controls. These samples were analyzed both for protein oxidation products (carbonyl) and the activities of two enzymes vulnerable to mixed-function oxidation, glutamine synthetase and creatine kinase. Glutamine synthetase is more sensitive to mixed-function oxidation than creatine kinase. Carbonyl content rises exponentially with age, at double the rate in the frontal pole compared with the occipital pole. Compared with young controls, both aged groups (AD and age-matched controls) have increased carbonyl content and decreased glutamine synthetase and creatine kinase activities, which are more marked in the frontal than occipital pole in all instances. We conclude that protein oxidation products accumulate in the brain and that oxidation-vulnerable enzyme activities decrease with aging in the same regional pattern (frontal more affected than occipital). However, only glutamine synthetase activity distinguishes AD from age-matched controls: Because glutamine synthetase activity is differentially reduced in the frontal pole in AD, we suggest that AD may represent a specific brain vulnerability to age-related oxidation.
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Alkylphenol ethoxylates (APEs) and related compounds recently have been reported to be estrogenic because it has been demonstrated in laboratory studies that they mimic the effects of estradiol both in vitro and in vivo. Chemicals referred to as "environmental estrogens" are suspected of causing health effects in both humans and wildlife through disruption of the endocrine system. In this review, the occurrence, environmental fate, and biological effects of APEs are presented. To provide understanding of the potential for endocrine disruption due to environmental estrogens, the physiology of estrogens in mammals and fish is also reviewed. The estrogenic potency of other environmental estrogens is compared to the potency of APE degradation products. The reproductive effects of estrogenic compounds are considered when evaluating the potential health effects of APEs. Given the reported environmental concentrations and bioconcentration factors of APE products, the potential for these compounds to produce estrogenic effects in the environment appears low. Although questions concerning the physiological effects of APEs and other environmental estrogens remain unanswered, there are indications that research is in progress that will lead to better understanding of the risks to humans and wildlife.
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The environmental toxicant 4-tert-octylphenol (OP) has been shown to exert estrogenic effects on mammalian cells in culture. Recent findings from our laboratories demonstrate clearly that OP administration disrupts reproductive hormone secretion in the adult male rat, quite likely as a result of estrogenic action. In the present study, we investigated the impact of these or other OP-induced changes on male reproductive tissues. Adult male rats were injected with OP (20 or 80 mg) or estradiol valerate (EV; 0.8 or 8 microg) s.c. in oil three times a week for either 1 or 2 mo. We found that an 80-mg dosage of OP for 2 mo or an 8-microg dosage of EV for 1 or 2 mo greatly reduced sperm numbers and adversely influenced the sizes, weights, and histological structures of the testes, epididymides, ventral prostate glands, seminal vesicles, and coagulating glands. The 80-mg dosage of OP for 1 mo reduced epididymal tubule size to a lesser extent than after 2 mo of treatment. Otherwise, treatment with 80 mg OP for 1 mo, 20 mg OP for 1 or 2 mo, or 0.8 microg EV for 1 mo had little or no effect on the histology of the tissues we examined. Additional evaluation of sperm morphology revealed marked increases in the proportions of head and tail abnormalities from animals that had received 80 mg of OP or 8 microg of EV for 1 mo and 20 mg of OP for 2 mo. The head abnormalities consisted mainly of pin heads, detached heads, and the absence of hooks, while tail abnormalities included mainly broken, coiled, and bent tails. Our results clearly demonstrate that OP can severely reduce the size and/or function of all of the male gametogenic and accessory reproductive organs studied. Moreover, the similarity of these cell and tissue changes between rats treated with OP and those treated with EV further suggests that OP may exert its action in an estrogenic-like manner.
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4-Tert-octylphenol (OP) is a prevalent environmental pollutant that has been shown to exert both toxic and estrogenic effects on mammalian cells. The effects of OP on the reproductive system of adult male vertebrates are virtually unknown. In the present study, we investigated the effects of chronic exposure to OP on reproductive hormone secretion in the adult male rat and compared the results qualitatively with those observed in other male rats treated chronically with estrogen. We injected corn oil vehicle or OP (20 or 80 mg) or estradiol valerate (EV; 0.8 or 8 microg) in oil s.c. into 2-mo-old male rats thrice weekly for either 1 or 2 mo. The 80-mg dosage of OP and one or both dosages of EV had the following effects: decreased anterior pituitary gland (APG) and serum LH and FSH concentrations; increased APG and serum prolactin (PRL) concentrations; increased APG/body weight ratios; decreased serum testosterone concentrations; decreased hematocrit; and decreased food consumption and body weight gain. To evaluate the response of the hypothalamus-APG to gonadal removal, we orchidectomized some of the rats after the end of treatment and decapitated them 3 wk later. In orchidectomized controls, serum LH and FSH concentrations rose markedly and serum PRL concentrations decreased. Similar changes were seen in orchidectomized rats treated previously with 20 or 80 mg OP. Moreover, there were no differences in mean serum LH, FSH, or PRL concentrations between controls and rats treated previously with either dosage of OP at 3 wk after orchidectomy. The results demonstrate that chronic administration of OP to adult male rats can adversely affect the secretion of reproductive hormones and strongly suggest that OP exerts these effects by acting like an estrogen. The opposite changes in LH, FSH, and PRL secretion observed after cessation of treatment with OP and orchidectomy suggest that chronic treatment with OP under the conditions of the present study did not result in any significant permanent deleterious effects on gonadotrophs or lactotrophs or the hypothalamic neurons controlling the secretion of the gonadotropins or PRL.
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Lipoic acid (thiotic acid) is being used as a dietary supplement, and as a therapeutic agent, and is reported to have beneficial effects in disorders associated with oxidative stress, but its mechanism of action remains unclear. We present evidence that lipoic acid induces a substantial increase in cellular reduced glutathione in cultured human Jurkat T cells human erythrocytes, C6 glial cells, NB41A3 neuroblastoma cells, and peripheral blood lymphocytes. The effect depends on metabolic reduction of lipoic acid to dihydrolipoic acid. Dihydrolipoic acid is released into the culture medium where it reduces cystine. Cysteine thus formed is readily taken up by the neutral amino acid transport system and utilized for glutathione synthesis. By this mechanism lipoic acid enables cystine to bypass the xc- transport system, which is weakly expressed in lymphocytes and inhibited by glutamate. Thereby lipoic acid enables the key enzyme of glutathione synthesis, gamma-glutamylcysteine synthetase, which is regulated by uptake-limited cysteine supply, to work at optimum conditions. Flow cytometric analysis of freshly prepared human peripheral blood lymphocytes, using monobromobimane labeling of cellular thiols, reveals that lipoic acid acts mainly to normalize a subpopulation of cells severely compromised in thiol status rather than to increase thiol content beyond physiological levels. Hence lipoic acid may have clinical relevance in restoration of severely glutathione deficient cells.
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Considerable attention has recently been focused on environmental chemicals that disrupt the reproductive system by altering steroid receptor function. Although numerous in vitro and in vivo methods have been shown to be useful approaches for identifying chemicals that can disrupt reproduction through a direct interaction with the estrogen receptor, it is imperative that the protocols selected be capable of detecting chemicals with a broad range of estrogenic activity. Here we evaluate the reliability of the 3-day uterotrophic assay for detecting chemicals with strong or weak estrogenic activity in both prepubertal and ovariectomized adult Long Evans rats. These data were compared to additional measures of estrogenic activity, which included the age of vaginal opening, the induction of cornified vaginal epithelial cells in ovariectomized adult rats, and estrous cyclicity in intact adult rats. Test chemicals selected for these studies included 17-beta-estradiol, ethynyl estradiol, methoxychlor, 4-tert-octylphenol, 4-nonylphenol and bisphenol A. Data from in vitro receptor binding assays compared the ability of the test chemicals to compete with [3H]-estradiol or [3H]-promegestone for binding to estrogen or progesterone receptors. As expected, the binding affinities for the estrogen receptor ranged from high to low, as reflected by Ki concentrations of 0.4 nM for 17-beta-estradiol and ethynyl estradiol, and 0.05-65 microM for 4-tert-octyphenol, 4-nonylphenol, and methoxychlor. Although none of the test chemicals demonstrated a high affinity for binding to the progesterone receptor, 4-tert-octylphenol and 4-nonylphenol exhibited a weak affinity, with Ki concentrations ranging from 1.2 to 3.8 microM. In vivo studies indicated that the 3-day uterotrophic assay in prepubertal rats was the best method for detecting estrogenic activity when compared with all other end points, based upon the dose-response data for ethynyl estradiol (0.01-0.1 mg/kg), 4-tert-octylphenol (50-200 mg/kg, oral), and 4-nonylphenol (25-100 mg/kg, oral). Although oral doses of ethynyl estradiol (0.01 mg/kg) and 4-nonylphenol (50 mg/kg) induced a significant increase in uterine weight in the prepubertal rats, these doses were ineffective for stimulating a similar response in ovariectomized adult rats. The age of vaginal opening was advanced following oral exposure from postnatal days 21-35 to ethynyl estradiol (0.01 mg/kg), methoxychlor (50 mg/kg), 4-tert-octylphenol (200 mg/kg), and 4-nonylphenol (50 mg/kg). Although bisphenol A (200 mg/kg, oral) induced a significant uterotrophic response within 3 days in prepubertal rats, doses up to 400 mg/kg failed to advance the age of vaginal opening. Monitoring changes in the vaginal epithelium of ovariectomized adult rats was the least effective method for detecting estrogenic activity for 4-tert-octylphenol and bisphenol A. The number of 4-5 day estrous cycles was reduced during a 25-day exposure to ethynyl estradiol (0.01 mg/kg), methoxychlor (50 mg/ kg), 4-tert-octylphenol (200 mg/kg), 4-nonylphenol (100 mg/kg), and bisphenol A (100 mg/kg) by oral gavage. Although long periods of extended diestrus (7-14 days) were generally correlated with exposure to ethynyl estradiol and 4-tert-octylphenol, the cycling patterns following exposure to methoxychlor, 4-nonylphenol and bisphenol A were not as clearly defined, with shorter periods of extended diestrus (4-7 days) and/or estrus (3-5 days) intermittently observed throughout the exposure period. Together these data provide a comparison of the 3-day uterotrophic assay with alternative measures of estrogenic activity for a group of test chemicals with a broad range of affinities for the estrogen receptor. These data can be useful during the assessment and validation of methods for screening environmental chemicals for endocrine disrupting activity.
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Alzheimer's disease (AD) is a progressive neurodegenerative disorder that destroys patient memory and cognition, communication ability with the social environment and the ability to carry out daily activities. Despite extensive research into the pathogenesis of AD, a neuroprotective treatment - particularly for the early stages of disease - remains unavailable for clinical use. In this review, we advance the suggestion that lipoic acid (LA) may fulfil this therapeutic need. A naturally occurring precursor of an essential cofactor for mitochondrial enzymes, including pyruvate dehydrogenase (PDH) and alpha-ketoglutarate dehydrogenase (KGDH), LA has been shown to have a variety of properties which can interfere with pathogenic principles of AD. For example, LA increases acetylcholine (ACh) production by activation of choline acetyltransferase and increases glucose uptake, thus supplying more acetyl-CoA for the production of ACh. LA chelates redox-active transition metals, thus inhibiting the formation of hydroxyl radicals and also scavenges reactive oxygen species (ROS), thereby increasing the levels of reduced glutathione. Via the same mechanisms, downregulation redox-sensitive inflammatory processes is also achieved. Furthermore, LA can scavenge lipid peroxidation products such as hydroxynonenal and acrolein. The reduced form of LA, dihydrolipoic acid (DHLA), is the active compound responsible for most of these beneficial effects. R-alpha-LA can be applied instead of DHLA, as it is reduced by mitochondrial lipoamide dehydrogenase, a part of the PDH complex. In this review, the properties of LA are explored with particular emphasis on how this agent, particularly the R-alpha-enantiomer, may be effective to treat AD and related dementias.
Chapter
Stereospecific and reversible interconversions of hydroxyl and ketone functions of steroids are catalyzed by pyridine nucleotide-dependent hydroxysteroid dehydrogenases. Enzymes of this class are widely distributed among microorganisms and in animal tissues. Discrete catalytic proteins are concerned with reversible oxidations at specific locations, i.e., of 3α-, 3β-, llβ, 17β-, 20α-, and 20β-hydroxysteroids. This chapter describes the assay method, purification procedure, and properties of hydroxysteroid dehydrogenases of Pseudomonas testosterone. 3α-hydroxysteroid dehydrogenase (α-enzyme) and (3 and 17) β-hydroxysteroid dehydrogenase (β-enzyme) are two steroid-induced hydroxysteroid dehydrogenases that are isolated from Pseudomonas testosteroni, a soil microorganism which can utilize testosterone, or related steroid hormones, as the only source of organic carbon. Both α- and β-enzymes are inactivated by low concentrations of heavy metal ions and p-chloromercuribenzoate. Both enzymes are protected against inactivation by DPN. β-Enzyme is powerfully stabilized by low concentrations of estradiol-17β. The asssay method, purification procedure, and properties of 20β-hydroxysteroid dehydrogenase of Streptornyces hydrogenmas is described in the chapter.
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The occurrence of endocrine-disrupting chemicals (EDCs) such as bisphenol A (BPA), 4-tert-octylphenol (OP), nonylphenol (NP) and its ethoxylates (NPEO) in wastewater generated in the Toronto area has been studied. In all, 97 samples from 40 facilities in ten different industry classes have been collected and analyzed. Widely divergent concentrations have been observed in these samples. They ranged from <0.01 to 195 μg/L for OP, from <0.1 to 253 μg/L for NP, from <2 to 117,570 μg/L for NPEO, and from <0.01 to 149 μg/L for BPA. The results show that the concentrations of NP and NPEO in these samples generally exceeded City of Toronto By-law (No. 457-2000) limits. The results also suggest that detergents based on NPEO are still extensively used by the commercial laundries, and also by the textile products and clothing industries. These facilities, together with several sources in the chemical and chemical products industries and the fabricated metal products industries are believed to be the major sources of NP and NPEO input into the sewer system in Toronto. In addition to the two facilities in the chemicals and chemical products sector, several commercial laundries also had significant on-site releases of BPA. Except for those collected from three facilities in the chemicals and chemical products industries, the levels of OP in these samples were generally low. Many industries in the Toronto area would have to take drastic actions to reduce releases of NPEO and NP if full compliance with the most recent City By-law regarding wastewater quality were to be achieved.
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The present study was designed to evaluate the effects of 4-tert-octylphenol (OP) on male testes and seminal vesicles of bank vole. Adult males kept under long or short photoperiod were orally administered OP (200mg/kg bw) for 30 or 60 days. Treatment for 30 days had no discernible effect on the parameters examined. Treatment for 60 days adversely influenced weights and histological structure of the testes and seminal vesicles. In these tissues, expression of 3β-hydroxysteroid dehydrogenase and androgen receptor and testosterone levels were reduced, whereas expression of aromatase and estrogen receptor α and estradiol levels were increased. The alterations were more evident in voles kept in long photoperiod. Taken together, it is suggested that adverse changes in bank vole reproductive tissues induced by long-term OP-exposure result from disturbed androgen and estrogen synthesis and action. Moreover, there might be a subtle difference in the sensitivity to OP between voles kept in different light conditions.
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This work is intended to study in vitro the ability of lipoic acid to protect erythrocytes against the oxidative damage resulting from exposure to gamma radiation through measurement of their rheological properties and to study the effects of detergent on their membrane solubility and permeability. Different doses of gamma radiation were applied: the most recommended and applied dose (25 Gy), and two higher doses, namely 50 and 100 Gy. The effect of addition of lipoic acid as well as its effect as a radioprotector was tested. The obtained results show changes in structural integrity of the erythrocyte cell membrane components as a result of oxidative damage due to gamma radiation that could be improved by pre-treatment with the antioxidant lipoic acid.
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Lipoic acid (1,2-dithiolane-pentanoic acid) is a dithiol which is effective in affording protection against oxidative stress by virtue of its two sulphydryl moieties. It is present in all kinds of eukaryotic and prokaryotic cells. As lipoamide, it functions as a cofactor in the multienzyme complexes that catalyse the oxidative decarboxylation of α-keto acids such as pyruvate, α-ketoglutarate, and branched-chain α-keto acids. The complete enzyme pathway responsible for the de novo synthesis of lipoic acid has not yet been elucidated. Octanoic acid appears to be the precursor for the eight-carbon fatty acid chain, and cysteine the source of sulfur. Lipoic acid is unique, among antioxidants, because it retains powerful antioxidant properties in both its reduced (dihydrolipoic acid) and oxidised (lipoic acid) forms. Both lipoic and dihydrolipoic acids have metal-chelating ability and quench activated oxygen species either in the cytosol or in the hydrophobic domains. Dihydrolipoic acid has more antioxidant properties than lipoic acid, and it plays an important role in the recycling of other oxidised radical scavengers such as glutathione, ascorbate and tocopherol. However, dihydrolipoic acid can also exert pro-oxidant properties both by its iron-reducing ability and by its ability to generate sulfur-containing radicals that can damage proteins. There are few quantitative data on lipoic acid contents in vegetables. It has been found in asparagus, wheat and potatoes, and recently, the presence of both lipoic and dihydrolipoic acids in roots, leaves and in the stroma of wheat has been demonstrated.
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Recent data have revealed that oxidative products and inflammatory mediators are increased in the insulin-resistant states of obesity and type 2 diabetes mellitus (T2DM). Obese patients with impaired glucose tolerance (IGT) are at high risk for developing T2DM and have high incidence of dyslipidemia. α-Lipoic acid (ALA) is a potent antioxidant with insulin sensitizing activity. However, it is not clear whether ALA is effective on lipid parameters in humans. This study has investigated 22 obese subjects with IGT (obese-IGT), 13 of whom underwent 2-week ALA treatment, 600 mg intravenously once daily. Before and after the treatment, euglycemic-hyperinsulinemic clamps were used to measure insulin sensitivity. Meanwhile, plasma lipids, oxidative products, and chronic inflammatory markers were measured. After treatment of ALA in obese-IGT patients, insulin sensitivity was improved, insulin sensitivity index (ISI) impressively enhanced by 41%. Plasma levels of free fatty acids (FFAs), triglyceride (TG), total cholesterol (T-Chol), low density lipoprotein-cholesterol (LDL-Chol), small dense LDL-Chol (sd-LDL), oxidized LDL-Chol (ox-LDL-Chol), very low density lipoprotein-cholesterol (VLDL-Chol) were all significantly decreased (P < 0.01). At the same time, both plasma oxidative products (malondialdehyde (MDA), 8-iso-prostaglandin) and inflammatory markers (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6)) were remarkably decreased (P < 0.01), while adiponectin was increased (P < 0.01). There are significant negative correlations between ISI and plasma FFAs, sd-LDL-Chol, ox-LDL-Chol, MDA, 8-iso-prostaglandin, TNF-α, and IL-6, and positive correlations with HDL-Chol and adiponectin in obese-IGT patients. The results indicate that short-term treatment with ALA can improve insulin sensitivity and plasma lipid profile possibly through amelioration of oxidative stress and chronic inflammatory reaction in obese patients with IGT.
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The purpose of the present study was to investigate the effects of prenatal exposure to octylphenol (OP) at the dose of 50mg/kg body weight on days 1, 7 and 14 of pregnancy on reproductive health of male rats at adulthood. F1 male rats from control and OP exposed animals were weaned and maintained up to postnatal day (PND) 100. The indices of testis, epididymis and seminal vesicles were significantly decreased in male rats exposed to OP during embryonic development when compared with controls. Significant reduction in the epididymal sperm count, viable sperms and motile sperms and number of tail coiled sperms (HOS-test) were observed in experimental rats when compared to control rats. The levels of serum testosterone and also activity levels of testicular hydroxysteroid dehydrogenases were significantly decreased with a significant increase in the serum follicle stimulating and leutinizing hormones in experimental rats. Furthermore, embryonic exposure to OP caused significant down regulation of StAR, 3ß hydroxysteroid dehydrogenase and 17ß hydroxysteroid dehydrogenase mRNAs in testis of adult rats as compared to control rats. The results of fertility studies revealed that there was an increase in the mating index in experimental rats with an increase in the pre- and post-implantation losses in rats cohabited with treated animals indicating poor male reproductive performance.
Article
In the present study, lipopolysaccharide (LPS), as an immune modulator in male adult rats and alpha-lipoic acid (ALA), as a powerful biological antioxidant and anti-inflammatory, are examined to help understanding the role of the immune and redox perturbation in testicular dysfunction with a possible protection. A total of 60 male Swiss albino rats were divided into 5 groups (10/group) respectively as follows Saline, ALA-vehicle, ALA (200mg/kg), LPS (5mg/kg) started with 20 rats and LPS+ALA. Obtained data from previously reported study, in our laboratory, and from the present one revealed that LPS induced marked reductions in sperm's count, motility and resulted in deterioration of the testicular histological features. In addition, LPS decreased testicular reduced glutathione (GSH) level and lactate dehydrogenase isoenzyme-x (LDH-x) activity. However, it increased testicular levels of malondialdehyde (MDA), nitric oxide (NO) and 8-hydroxydeoxyguanosine (8-HDG) in testicular DNA, along with increased serum IL-2 level. In contrast, rats pretreated with ALA showed almost complete normalization of all the tested parameters. In conclusion, LPS induced perturbation of the immune-testicular barrier as a result of redox imbalance with a subsequent testicular dysfunction. Pretreatment with ALA ameliorated all these effects by its immune-modulator and antioxidant mechanisms suggesting a protective role against male infertility in septic or severely infected patients.
Article
Lipoic acid (LA) is a known antioxidant currently used as a therapy in patients with vascular and metabolic disorders. We tested the hypothesis that lipoic acid is protective against the cell death observed following stroke. Lipoic acid was administered 30minutes prior to, or immediately following removal of sutures used to occlude the middle cerebral artery (MCA) in male Sprague-Dawley rats. Following removal of the sutures, the MCA territory was allowed to undergo 5.5hrs of reperfusion. This ischemia/reperfusion (I/R) resulted in a focal infarct restricted to the prefrontal cortex (24±3mm(3)). Pretreatment with LA 30minutes prior to occlusion resulted in a dose-dependent reduction in infarct volume. This reduction in infarct volume was not observed when the LA was administered immediately prior to reperfusion (30minutes post-occlusion). To investigate a potential hemodynamic mechanism for this LA-induced neuroprotection, blood pressure, heart rate and baroreceptor reflex sensitivity (BRS) were measured. Intravenous administration of LA did not result in any significant changes in any of these parameters compared to saline-treated rats. Similarly, there was no significant contribution of systemic nitric oxide or alteration in cerebral perfusion measured following pretreatment with lipoic acid or during the course of occlusion and reperfusion compared with saline-treated rats. Western blot analysis of tissue from the ischemic cortex showed an increase in protein expression of superoxide dismutase (SOD2), but not SOD1, in LA pretreated rats. This suggests a potential mechanism of action contributing to the LA-induced neuroprotection observed. Furthermore, the data in the present investigation suggest the potential use of LA pretreatment as a neuroprotectant in stroke patients.
Article
OP (octylphenol), an environmental oestrogen was administered, and differentially expressed proteins were analysed in mice testes to clarify its mechanism of action in male sterility. Male Kunming suckling mice (10 days old) were subcutaneously injected with OP at a dose of 10 μg/kg per day, 50 μg/kg per day and 100 μg/kg per day as low-, medium- and high-dose groups, respectively, for 35 days. Animals in the control group received subcutaneous injections of olive oil at a dose of 10 μl/mouse per day. Serum oestradiol, testosterone, FSH (follicle stimulating hormone) and LH (luteinizing hormone) levels were measured on day 45. The left testes were removed for tissue analysis, and the right testes were analysed for differentially expressed proteins by using two-dimensional gel electrophoresis and MS. Tissue analysis showed that mice spermatogenesis was blocked at the round spermatid stage in the high-dose group, whereas no such changes were found in the medium- and low-dose groups. Higher serum oestradiol (P<0.05) and lower testosterone (P<0.05) levels were found in the medium- and high-dose groups. There was no significant difference in serum oestradiol and testosterone levels in the low-dose and control groups. No significant influence of OP was seen on serum FSH and LH levels in all OP-treated animals. The results from four differentially expressed proteins such as PPIA (peptidyl-prolyl cis-trans isomerase A), PEBP1 (phosphatidylethanolamine-binding protein1), TPI (triose-phosphate isomerase) and TCP-1 (T-complex protein 1) in the high-dose and control groups showed up-regulation of PPIA expression and down-regulation in PEBP1, TPI and TCP-1 expressions. These findings will contribute to clarify the mechanism of male sterility by environmental oestrogens.
Article
Bisphenol A (BPA) impairs spermatogenesis in animals, but human studies are lacking. We measured urinary BPA concentrations, semen quality, and sperm DNA damage (comet assay) in 190 men recruited through an infertility clinic. BPA was detected in 89% of samples, with a median (interquartile range [IQR]) concentration of 1.3 (0.8-2.5) ng/mL. Urinary BPA concentration was associated with slightly elevated, though not statistically significant, odds for below reference sperm concentration, motility, and morphology. When modeled as continuous dependent variables, an IQR increase in urinary BPA concentration was associated with declines in sperm concentration, motility, and morphology of 23% (95%CI -40%, -0.3%), 7.5% (-17%, +1.5%), and 13% (-26%, -0.1%), respectively, along with a 10% (0.03%, 19%) increase in sperm DNA damage measured as the percentage of DNA in comet tail. In conclusion, urinary BPA may be associated with declined semen quality and increased sperm DNA damage, but confirmatory studies are needed.
Article
Many of the hypotheses have been suggested to explain the mechanism of the secondary effects of traumatic spinal cord injury (TSCI) as follows: ischaemia/reperfusion disability theory, free radicals theory, exitotoxicity theory, immunological destruction theory, apoptosis theory. Recently, free radicals,lipid peroxidation reactions and apoptosis theories have been much more accepted than others. In this study, possible protective effects of the alpha lipoic acid were evaluated in the traumatic spinal cord of rats. Using a well characterised weight drop technique, spinal cord contusions were formed to 48 Wistar albino rats at thoracal 8–10 level. After alpha lipoic acid and methylprednisolone were administered intraperitoneally, the spinal cord tissues were harvested for histopathological and biochemical studies. Histopathological examination results showed that neither methylprednisolone nor alpha lipoic acid can play an act to decrease or block the neural tissue destruction and necrosis in hyperacute and subacute stage of the TSCI in rats. Biochemical study results showed that alpha lipoic acid was much more decreased the lipid peroxidation levels than methylprednisolone in subacute stage. However, none of the agents was changed the myeloperoxidation level in subacute stage. Alpha lipoic acid and methylprednisolone administrations did not alter the onset or degree of necrosis at the zone of the TSCI in rats. On the other hand, alpha lipoic acid is more effective than methylprednisolone treatment for the prevention of lipid peroxidation after spinal cord injury.
Article
The imbalance between reactive oxygen species (ROS) production and total antioxidant capacity (TAC) in seminal fluid indicates oxidative stress and is correlated with male infertility. A composite ROS–TAC score may be more strongly correlated with infertility than ROS or TAC alone. We measured ROS, TAC, and ROS–TAC scores in semen from 127 patients and 24 healthy controls. Of the patients, 56 had varicocele, eight had varicocele with prostatitis, 35 had vasectomy reversals, and 28 had idiopathic infertility. ROS levels were higher among infertile men, especially those with varicocele with prostatitis (mean ± SE, 3.25 ± 0.89) and vasectomy reversals (2.65 ± 1.01). All infertile groups had significantly lower ROS–TAC scores than control. ROS–TAC score identified 80% of patients and was significantly better than ROS at identifying varicocele and idiopathic infertility. The 13 patients whose partners later achieved pregnancies had a mean ROS–TAC score of 47.7 ± 13.2, similar to controls but significantly higher than the 39 patients who remained infertile (35.8 ± 15.0; P < 0.01). ROS–TAC score is a novel measure of oxidative stress and is superior to ROS or TAC alone in discriminating between fertile and infertile men. Infertile men with male factor or idiopathic diagnoses had significantly lower ROS–TAC scores than controls, and men with male factor diagnoses that eventually were able to initiate a successful pregnancy had significantly higher ROS–TAC scores than those who failed.
Article
Inflammatory reactions to microbial infections may cause male infertility. The mechanisms of inhibition of spermatogenesis can be studied in vitro using rat Sertoli cells. Bacterial lipopolysaccharides (LPS) induce acute inflammations. So LPS treated Sertoli cells can be used to test for new therapeutic compounds. The present study aimed to investigate the protective efficacy of dl-alpha-lipoic acid (LA) on lipopolysaccharide (LPS)-induced oxidative stress in adult rat Sertoli cells. Sertoli cells were divided into 4 groups. Group I served as a control incubated with water (vehicle). Groups II and IV were incubated with 100 microM LA for 24h before incubating Groups III and IV with 50 microg/ml lipopolysaccharide (LPS) for 12h. In Group III cells (LPS-treated, no LA) the lactate concentration was decreased whereas hydrogen peroxide production and lipid peroxidation were significantly increased. Moreover, the activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, catalase, glutathione-S-transferase, glutathione reductase were reduced. The concentrations of antioxidant molecules such as reduced glutathione and vitamin C were significantly decreased. The activities of enzymes normally elevated in Sertoli cells, gamma-glutamyl transpeptidase and beta-glucuronidase, were significantly decreased. Treatment with LA (100 microM) for 24h before LPS-treatment (Group IV), prevented these changes in enzyme activities and metabolite concentrations. Therefore, LA may have a cyto-protective role during LPS-induced inflammation in adult rat Sertoli cells.
Article
Bisphenol A (BPA), an estrogenic environmental contaminant is also known for oxidative stress-inducing effect. Malnutrition is recognized as a confounding factor in oxidative stress. However, little is known about effect of malnutrition on oxidative stress induced by BPA or other endocrine disrupting chemicals (EDCs). We studied effect of malnutrition (iron deficiency) in rats chronically exposed to low levels of BPA taking into consideration the oxidative stress and antioxidant status in liver, kidney and gonads. Iron deficiency significantly elevated level of lipid peroxidation in BPA-exposed rats. Similarly, decrease in reduced glutathione level was more significant in rats maintained on iron deficient diet compared to those maintained on normal diet. Iron deficiency also significantly modulated activities of vital antioxidant enzymes in all the tissues. Female rats showed more vulnerability than males to iron-deficiency modulated effects of BPA on the above parameters. This study demonstrated that malnutrition, especially iron deficiency, might act as a confounding factor in EDC-induced oxidative stress. However, more studies may be needed to confirm effect of nutritional factors on estrogenic activity of BPA or other EDCs.
Article
Diabetes is a common metabolic disorder that is usually accompanied by increased production of reactive oxygen species or by impaired antioxidant defenses. Importantly, oxidative stress is particularly relevant to the risk of cardiovascular disease. Alpha-lipoic acid (LA), a naturally occurring dithiol compound, has long been known as an essential cofactor for mitochondrial bioenergetic enzymes. LA is a very important micronutrient with diverse pharmacologic and antioxidant properties. Pharmacologically, LA improves glycemic control and polyneuropathies associated with diabetes mellitus; it also effectively mitigates toxicities associated with heavy metal poisoning. As an antioxidant, LA directly terminates free radicals, chelates transition metal ions, increases cytosolic glutathione and vitamin C levels, and prevents toxicities associated with their loss. These diverse actions suggest that LA acts by multiple mechanisms both physiologically and pharmacologically. Its biosynthesis decreases as people age and is reduced in people with compromised health, thus suggesting a possible therapeutic role for LA in such cases. Reviewed here is the known efficacy of LA with particular reference to types 1 and 2 diabetes. Particular attention is paid to the potential benefits of LA with respect to glycemic control, improved insulin sensitivity, oxidative stress, and neuropathy in diabetic patients. It appears that the major benefit of LA supplementation is in patients with diabetic neuropathy.
Article
The reaction of lipid peroxides in animal tissues with thiobarbituric acid was dependent on pH of the reaction mixture as was the case for linoleic acid hydroperoxide. The optimum pH was found to be 3.5. Taking this fact into consideration, a standard procedure for the assay of lipid peroxide level in animal tissues by their reaction with thiobarbituric acid was developed as follows. Ten percent ( tissue homogenate was mixed with sodium dodecyl sulfate, acetate buffer (pH 3.5), and aqueous solution of thiobarbituric acid. After heating at 95°C for 60 min, the red pigment produced was extracted with n-butanol-pyridine mixture and estimated by the absorbance at 532nm. As an external standard, tetramethoxy-propane was used, and lipid peroxide level was expressed in terms of nmol malondialdehyde. Using this method, the liped peroxide level in the liver of rats suffering from carbon tetrachloride intoxication was investigated. The results were in good agreement with previously reported data obtained by measuring diene content.
Article
Sex hormone binding globulin (SHBG) is a glycoprotein possessing high affinity binding for 17 β-hydroxysteriod hormones such as testosterone and oestradiol. It is probably synthesized in the liver, plasma concentrations being regulated by, amongst other things, androgen/oestrogen balance, thyroid hormones, isulin and dietary factors. it is involved in transport of sex steroids in plasma and its concentration is a major factor regulating their distribution between the protein-bound and free states. Its detailed role in the delivery of hormones to target tissues is not yet clear. Plasma SHBG concentrations are affected by a number of different diseases, high values being found in hyperthyroidism, hypogonadism, androgen insensitivity and hepatic cirrhosis in men. Low concentrations are found in myxoedema, hyperprolactinaemia and syndromes of excessive androgen activity. Concentrations are also affected by drugs such as androgens, oestrogens, thyroid hormones and anti-convulsants. Measurement of SHBG is useful in the evaluation of mild disorders of androgen metabolism and enables identification of those women with hirsutism who are more likely to respond to oestrogen therapy. Testosterone: SHBG ratios correlate well with both measured and calculated values of free testosterone and help to discriminate subjects with excessive androgen activity from normal individuals.
Article
Measurement of sex-steroid-binding plasma protein in serum of healthy individuals in prepuberty and puberty (74 males and 94 females) was performed using a radioimmunoassay procedure. An age-related decrease of serum SBP was demonstrated during these ages in both sexes. In parallel studies, the serum level of testosterone, oestradiol and dehydroepiandrosterone was evaluated in subjects under 20 years of age. A rise of serum dehydroepiandrosterone levels in both sexes was observed to occur at approximately 8 years of age, being a little bit earlier than the ages for testosterone to rise in males and for oestradiol to rise in females, both of them being at about 10 years of age, respectively. When the testosterone/sex-steroid-binding plasma protein ratio was evaluated as an index of free testosterone concentration in serum, a sharp increase of the ratio was found to occur at 10 years of age and to continue during puberty in both sexes with more marked increment in males than in females. It was suggested that the decrease of SBP in puberty might be largely influenced by alteration in the hormonal balance of testosterone, oestradiol and dehydroepiandrosterone.
Article
The reduction of nitro blue tetrazolium (NitroBT) with NADH mediated by phenazine methosulfate (PMS) under aerobic conditions was inhibited upon addition of superoxide dismutase. This observation indicated the involvement of superoxide aninon radical (O2−) in the reduction of NitroBT, the radical being generated in the reoxidation of reduced PMS. Similarly, the reduction of NitroBT coupled to D-amino acid oxidase-PMS system under aerobic conditions was also inhibited by superoxide dismutase. A simple method for detecting superoxide dismutase is described.
Article
The purification of homogeneous glutathione S transferases B and C from rat liver is described. Kinetic and physical properties of these enzymes are compared with those of homogeneous transferases A and E. The letter designations for the transferases are based on the reverse order of elution from carboxymethylcellulose, the purification step in which the transferases are separated from each other. Transferase B was purified on the basis of its ability to conjugate iodomethane with glutathione, whereas transferase C was purified on the basis of conjugation with 1,2 dichloro 4 nitrobenzene. Although each of the 4 enzymes can be identified by its reactivity with specific substrates, all of the enzymes are active to differing degrees in the conjugation of glutathione with p nitrobenzyl chloride. Assay conditions for a variety of substrates are included. All four glutathione transferases have a molecular weight of 45,000 and are dissociable into subunits of approximately 25,000 daltons. Despite similar physical properties and overlapping substrate specificities of these enzymes, only transferases A and C are immunologically related.
Article
A singlestableLiebermann-Burchard reagentwas preparedand studiedfor the rapid andaccurate determination of total cholesterol in serum. The preparation, stability, and developed spectralcharacterof the proposed reagentwere assessed. Reproduci- bility, recovery,and interferencestudieson pure standardand patient sera were performed using the Abell-Kendall method as reference. The influence of water, protein, bilirubin, hemoglobin,and other serum constituents was evaluated. 0 NE OF THE INCREASINGLY significant medical-biochemical problems of today concerns the relationship of dietary lipids, including choles- terol, to coronary artery disease. Hypercholesterolemia is a frequent finding in human atherosclerosis (1). The unusually large number of methods for the determination of cholesterol in blood points up the difficulties in obtaining a satisfactory method for analysis. One of the most widely used color reactions is that of Liebermann-Burchand (LB). A prolific literature has built up on this popular procedure for cholesterol with many conflicting opinions. Although most workers have used the three reagents, acetic anhydride, acetic, and sulfuric acids for the preparation of the LB reagent, there are almost as many compositions as there are investi- gators. Only recently have new data been presented on the stability of a single LB reagent. Previously, workers were cautioned to prepare this reagent freshly each day. The object of this work was to prepare a single stable LB reagent for the direct assay of cholesterol in serum. In the direct method for cholesterol, serum is added to LB reagent without removal of protein. Direct methods include the technic of
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Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products. Four major components of the head are cleaved during the process of assembly, apparently after the precursor proteins have assembled into some large intermediate structure.
Article
Genetically determined, sex-linked erythrocyte glucose-6-phosphate dehydrogenase deficiency is generally more severe and extensive in affected Caucasians than Negroes. Thus, the former have lower levels of enzyme activity in erythrocytes, and the defect is demonstrable in nucleated tissue, such as leukocytes, liver, and skin, as well as in other nonnucleated tissue, such as platelets. The present study indicates that in affected Chinese the enzyme defect in erythrocytes is severe and is present also in leukocytes, platelets, and hepatic, adrenal, and renal tissue. Decreased glucose-6-phosphate dehydrogenase levels in the adrenals and kidneys of affected subjects are reported for the first time. No deficiency in 6-phosphogluconic acid dehydrogenase was encountered.
Article
Exposure of human plasma to gas phase cigarette smoke (CS) produces a depletion of ascorbic acid, peroxidation of lipids (Frei et al. Biochem J 1991; 277: 133-8), and protein modification (as measured by protein carbonyl accumulation and loss of sulfhydryl groups) (Reznick et al. Biochem J 1992; 286: 607-11). CS contains both saturated and unsaturated aldehydes. The contribution of these aldehydes to the damaging effects of CS on human plasma was investigated. Aldehydes present in CS did not cause a depletion of plasma antioxidants such as ascorbic acid or alpha-tocopherol and did not induce plasma lipid peroxidation. Aldehydes decreased plasma protein sulfhydryl concentrations but increased protein carbonyls. The thiols glutathione and dihydrolipoic acid had a significant effect in reducing aldehyde-induced protein modifications.
Article
Reactive oxygen species are thought to be involved in a number of types of acute and chronic pathologic conditions in the brain and neural tissue. The metabolic antioxidant alpha-lipoate (thioctic acid, 1, 2-dithiolane-3-pentanoic acid; 1, 2-dithiolane-3 valeric acid; and 6, 8-dithiooctanoic acid) is a low molecular weight substance that is absorbed from the diet and crosses the blood-brain barrier. alpha-Lipoate is taken up and reduced in cells and tissues to dihydrolipoate, which is also exported to the extracellular medium; hence, protection is afforded to both intracellular and extracellular environments. Both alpha-lipoate and especially dihydrolipoate have been shown to be potent antioxidants, to regenerate through redox cycling other antioxidants like vitamin C and vitamin E, and to raise intracellular glutathione levels. Thus, it would seem an ideal substance in the treatment of oxidative brain and neural disorders involving free radical processes. Examination of current research reveals protective effects of these compounds in cerebral ischemia-reperfusion, excitotoxic amino acid brain injury, mitochondrial dysfunction, diabetes and diabetic neuropathy, inborn errors of metabolism, and other causes of acute or chronic damage to brain or neural tissue. Very few neuropharmacological intervention strategies are currently available for the treatment of stroke and numerous other brain disorders involving free radical injury. We propose that the various metabolic antioxidant properties of alpha-lipoate relate to its possible therapeutic roles in a variety of brain and neuronal tissue pathologies: thiols are central to antioxidant defense in brain and other tissues. The most important thiol antioxidant, glutathione, cannot be directly administered, whereas alpha-lipoic acid can. In vitro, animal, and preliminary human studies indicate that alpha-lipoate may be effective in numerous neurodegenerative disorders.
Article
We conducted a study to investigate the relation between estrogenic effects of p-tert-octylphenol (OP) and serum concentration as well as treatment duration. Adult ovariectomized rats were given daily subcutaneous injections of OP for 2 and 14 days. 17beta-Estradiol was also administrated at a dose of 5 microg/kg. OP was detected in serum at doses of 25 mg/kg and above for 2 days and with multiple doses (14 days) of 12.5 mg/kg. Uterine weights and luminal epithelial height were increased although the effects were weak compared to 17beta-estradiol. Estrous conversion of the vaginal smear was detected only in 14-day-treated animals. OP-treatment for 2 days caused a dose-related increase in proliferation of uterine luminal, glandular, and stromal cells and vaginal epithelial cells. From the 14-day experiment, the minimum estrogenic dose level of OP was concluded to be 25 mg/kg/day and the serum level at the dose was determined to be about 80 ng/ml. These findings demonstrated that OP exerts estrogenic activity in the female reproductive tract of ovariectomized rats only at high levels of exposure and that the effects are fundamentally related to serum OP levels.
Article
This study was designed to investigate the role of graded doses of lipoic acid pretreatment against cisplatin-induced nephrotoxicity. Male Wistar rats were divided into six groups and treated as follows: 1) vehicle (saline) control; 2) cisplatin (16 mg/kg, intraperitoneally); 3) lipoic acid (100 mg/kg, intraperitoneally); 4) cisplatin plus lipoic acid (25 mg/kg); 5) cisplatin plus lipoic acid (50 mg/kg) and 6) cisplatin plus lipoic acid (100 mg/kg). Rats were sacrificed three days after treatment, and plasma as well as kidneys were isolated and analyzed. Plasma creatinine increased (677% of control) following cisplatin administration alone which was decreased by lipoic acid in a dose-dependent manner. Cisplatin-treated rats showed a depletion of renal glutathione (GSH), increased oxidized GSH and decreased GSH/GSH oxidized ratio (62%, 166% and 62% of control), respectively which were restored with lipoic acid pretreatment. Renal superoxide dismutase, catalase, glutathione peroxidase (GSH peroxidase) and glutathione reductase activities decreased (62%, 75%, 62% and 80% of control), respectively, and malondialdehyde content increased (204% of control) following cisplatin administration, which were restored with increasing doses of lipoic acid. The renal platinum concentration increased following cisplatin administration, which was possibly decreased by chelation with lipoic acid. The data suggest that the graded doses of lipoic acid effectively prevented a decrease in renal antioxidant defense system and prevented an increase in lipid peroxidation, platinum content and plasma creatinine concentrations in a dose-dependent manner.
Article
Distributions of alkylphenols (APs) [i.e., nonylphenol (NP), octylphenol (OP)], and nonylphenol monoethoxylate (NP1EO) in wastewater effluents, river water, and riverine and bay sediments in the Tokyo metropolitan area were demonstrated. During sewage treatments, NP and OP were efficiently removed from the sewage effluents through activated sludge treatments. Greater removal for NP (93% on average) than OP (84% on average) was consistent with their partitioning behavior to particles in primary and secondary effluents. NP concentrations in the river water samples ranged from 0.051 to 1.08 microg/L with higher concentrations in summer and spring than in colder seasons. In the river water samples, approximately 20% of NP was found in the particulate phase. Organic carbon-normalized apparent partition coefficients (K'OC) for NP (10(5.22 +/- 0.38)) and OP (10(4.65 +/- 0.42)) were 1 order of magnitude higher than those expected from their octanol-water partition coefficients (K(OW)), indicating strong affinity of APs to aquatic particles. Among NP isomers, no significant differences in their K'OC values were suggested. This is consistent with surprisingly uniform isomer peak profiles among the technical standard and all the environmental samples analyzed. NP and OP were widely distributed in the river sediments in Tokyo, and relatively high concentrations (0.5-13.0 microg/g dry) of NP were observed in a long reach (approximately 10 km) in the Sumidagawa River. In situ production of APs in the river sediment was suggested. Seaward decreasing trend in APs concentration was observed from the estuary to the Tokyo Bay. APs were well preserved in a sediment core collected from the bay. The profile shows subsurface maximum of AP concentrations in the layer deposited around the mid-1970s. The recent decrease in AP concentrations can be attributed to the legal regulation of industrial wastewater in the early 1970s.