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The baleful effect of penconazole fungicide on clam Ruditapes decussatus gills: fatty acids composition, redox status and histological features The baleful effect of penconazole fungicide on clam Ruditapes decussatus gills: fatty acids composition, redox status and histological features
Abstract
The baleful effect of penconazole fungicide on clam Ruditapes decussatus gills: fatty acids composition, redox status and histological features, Chemistry and Ecology, ABSTRACT Penconazole is a widely used fungicide to control critical fungal diseases of crops. This study aimed to elucidate the effects of PEN exposure, for 96 h, on fatty acids composition, redox status, and histopathological injuries in Ruditapes decussatus gills under different concentrations (4, 40, and 400 µg/L). Compared to the control group, our results showed an increase in saturated and monounsaturated fatty acids. However, the levels of polyunsaturated fatty acids were diminished, mainly those of eicosapentaenoic, docosahexaenoic, and arachidonic acids upon exposure to PEN. Depletion of PUFAs' levels, particularly the long-chain and double-bond-rich ones, can affect membrane fluidity, and disrupt membranes' biological functions, such as cell signalling, membrane transport, and protection against other environmental stresses. Herein, PEN uptake also results in enhanced oxidative stress by increasing levels of the ferric-reducing antioxidant power, hydrogen peroxidase, malondialdehyde, advanced oxidation protein products, and protein carbonyls. Moreover, changes in both enzymatic and non-enzymatic antioxidants were noticeable, indicating the stimulation of the antioxidant defense system. Adverse histological alterations were detected in PEN-treated specimens' gill tissues, supporting our biochemical findings. Overall, in the current study, redox status was related to changes in fatty acid composition, contributing to a better understanding of the PEN-toxicity mechanism in clams.
... The stressful ailment of respiratory impairment due to the toxic effect of primextra on the gills [30]. The observed increasing state of inactivity with both increasing concentrations and exposure period [31]. The accumulation of the mucus might have resulted from an increase in the activity of the mucus cells following exposure to the toxicant. ...
Contamination of aquatic ecosystem is a matter of great concern. Primextra chemical constitute potential hazards to aquatic environment. The aim of the study was to evaluate the toxicity of primextra on the juveniles of Clarias gariepinus. Mixed sexes of Clarias gariepinus juveniles were obtained from school of Agriculture, Mando, Kaduna, and transported to the Zoological Garden, Kaduna State University. “Primextra Gold” containing atrazine (370g/l) and S-metolachlor (290g/l) were purchased from Central Market Kaduna. Fish were acclimatized for two weeks and fed with 2mm “Ala Aqua”. Stock solution was prepared by adding 1ml of the herbicide obtained in concentration of 50g/ml to 99ml of water and used to prepare 0, 10, 13, 16, 19 and 22.1mg/l concentrations. Fish were randomly selected, weighed and distributed into eighteen (18) plastic aquarium tanks with each containing 10 juveniles for the acute toxicity and sub-lethal toxicity bioassay. Behavioural responses and mortality rate were observed. The results of the acute toxicity bioassay, the 96-hours LC50 was calculated. Haematological profile including total erythrocyte count (RBC), haemoglobin concentration (Hb), haematocrit (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular haemoglobin (MCH), leukocyte count (WBC) and the differential leukocyte count (DLC) were determined. Length and weight were measured. The fish showed abnormal swimming movements. The first mortality was observed at 24 hours at 10mg/L, 13mg/L, 16mg/L, 19mg/L and 22mg/L concentrations while the RBC count was 2.24±0.00 x106 cell/ml. Results of the histopathological studies of the liver of C. gariepinus exposed to acute and sub-lethal of primextra revealed prominent changes in the liver such as perivascular cuffing around the central vein and mild congestion of the sinusoids. The results of the present study revealed that primextra was toxic to Clarias gariepinus with LC50 value of 12.66mg/L
The blood clam (Tegillarca granosa) is being developed into a model bivalve mollusc for assessing and monitoring marine pollution on the offshore seabed. However, the information on the response of blood clam to PAHs, an organic pollutant usually deposited in submarine sediment, remains limited. Herein, we employed multiple biomarkers, including histological changes, oxidative stress, neurotoxicity and global DNA methylation, to investigate the effects of 10 and 100 μg/L Bap exposure on the blood clams under laboratory conditions, as well as the potential mechanisms. Acute Bap exposure can induce significant morphological abnormalities in gills as shown through hematoxylin–eosin (H.E) staining, providing an intuitive understanding on the effects of Bap on the structural organization of the blood clams. Meanwhile, the oxidative stress was significantly elevated as manifested by the increase of antioxidants activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione-s-transferase (GST), lipid peroxidation (LPO) level and 8-hydroxy-2′-deoxyguanosine (8-OHdG) content. The neurotoxicity was also strengthened by Bap toxicity manifested as inhibited acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) activities. In addition, the global DNA methylation level was investigated, and a significant DNA hypomethylation was observed in Bap exposed the blood clam. The correlation analysis showed that the global DNA methylation was negatively correlated with antioxidants (SOD, CAT and POD) activities, but positively correlated choline enzymes (AChE and ChAT) activities. These results collectively suggested that acute Bap exposure can cause damage in gills structures in the blood clam possibly by generating oxidative stress and neurotoxicity, and the global DNA methylation was inhibited to increase the transcriptional expression level of antioxidants genes and consequently elevate antioxidants activities against Bap toxicity. These results are hoped to shed some new light on the study of ecotoxicology effect of PAHs on marine bivalves.
Penconazole (PEN) is a widely used systemic fungicide to treat various fungal diseases in plants but it leaves residues in crops and food products causing serious environmental and health problems. N-acetylcysteine (NAC) is a precursor of the antioxidant glutathione in the body and exerts prominent antioxidant and anti-inflammatory effects. The present study aimed to explore the mechanistic way of NAC to ameliorate the PEN neurotoxicity in male rats. Twenty-eight male rats were randomly divided into four groups (n = 7) and given the treated material via oral gavage for 10 days as the following: Group I (distilled water), Group II (50 mg/kg body weight [bwt] PEN), Group III (200 mg/kg bwt NAC), and Group IV (NAC + PEN). After 10 days all rats were subjected to behavioral assessment and then euthanized to collect brain tissues to perform oxidative stress, molecular studies, and pathological examination. Our results revealed that PEN exhibits neurobehavioral toxicity manifested by alteration in the forced swim test, elevated plus maze test, and Y-maze test. There were marked elevations in malondialdehyde levels with reduction in total antioxidant capacity levels, upregulation of messenger RNA levels of bax, caspase 3, and caspase 9 genes with downregulation of bcl2 genes. In addition, brain sections showed marked histopathological alteration in the cerebrum and cerebellum with strong bax and inducible nitric oxide synthetase protein expression. On the contrary, cotreatment of rats with NAC had the ability to improve all the abovementioned neurotoxic parameters. The present study can conclude that NAC has a neuroprotective effect against PEN-induced neurotoxicity via its antioxidant, anti-inflammatory, and antiapoptotic effect. We recommend using NAC as a preventive and therapeutic agent for a wide variety of neurodegenerative and neuroinflammatory disorders.
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 four 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 the similar physical properties and overlapping substrate specificities of these enzymes, only transferases A and C are immunologically related.
Penconazole, a triazole fungicide, is widely used worldwide to increase agricultural production and to control fungus. Bivalves, especially mussels, are specific biomonitor organisms of pollution in aquatic ecosystems. This study deals with the possible toxic effects of exposure to penconazole on Na + /K +-ATPase, Mg 2+-ATPase, Ca 2+-ATPase, and Total-ATPase activities in the gills of freshwater mussels (Unio mancus). In this context, freshwater mussels were exposed to different concentrations of penconazole (1, 10, 100, and 1000 µg AI L-1) in 96 hours static-renewal test system. The commercial form of penconazole (TOPAS ® 100 EC, Syngenta, Germany) was used in toxicity tests. The actual penconazole concentrations in the exposure media were determined by LC-MS/MS analysis. According to the LC-MS/MS analysis results, the actual penconazole concentrations in the exposure media were determined to be approximately 25% lower than the nominal penconazole concentrations. After 96 hours of exposure, the highest concentration of penconazole caused significant inhibition of ATPase activities except Mg 2+-ATPase activity (P < 0.05). The observed data indicated that acute penconazole exposure may be a potential risk for freshwater mussels and that ATPase enzymes are important and useful biochemical markers for aquatic toxicology studies. Öz: Triazol bir fungusit olan penkonazol, tarımsal üretimi arttırmak ve fungusları kontrol etmek için dünya çapında yaygın olarak kullanılmaktadır. Çift kabuklu yumuşakçalar, özellikle midyeler, sucul ekosistemlerde kirliliğin spesifik biyomonitor organizmalarıdır. Bu çalışmada tatlı su midyelerinin (Unio mancus) solungaç Na + /K +-ATPaz, Mg 2+-ATPaz, Ca 2+-ATPaz ve Total-ATPaz aktiviteleri üzerine penkonazol maruziyetinin olası toksik etkileri değerlendirilmiştir. Bu amaçla, 96 saatlik statik yenileme test sisteminde tatlı su midyeleri farklı konsantrasyonlarda penkonazole (1, 10, 100 ve 1000 µg AI L-1) maruz bırakılmıştır. Toksisite testlerinde penkonazolün ticari formu (TOPAS ® 100 EC, Syngenta, Almanya) kullanılmıştır. Maruziyet ortamındaki gerçek penkonazol konsantrasyonları LC-MS/MS analizi ile belirlenmiştir. LC-MS/MS analizi sonuçlarına göre, maruziyet ortamındaki gerçek penkonazol konsantrasyonlarının, nominal penkonazol konsantrasyonlarından yaklaşık %25 oranında daha düşük olduğu belirlenmiştir. 96 saatlik maruziyetten sonra, en yüksek penkonazol konsantrasyonu Mg 2+-ATPaz hariç diğer ATPaz aktivitelerinin önemli düzeyde inhibisyonuna neden olmuştur (P < 0.05). Elde edilen veriler, akut penconazol maruziyetinin tatlı su midyeleri için potansiyel bir risk olabileceğini ve ATPaz enzimlerinin akuatik toksikoloji çalışmaları için önemli ve faydalı biyokimyasal belirteçler olduğunu göstermiştir. Anahtar kelimeler: Penkonazol toksisitesi, tatlı su midyesi, ATPazlar, LC-MS/MS.
Penconazole is one of the most widely used fungicides all over the world, and since it spreads to large environments, its toxic effects on non-target organisms are of great concern. The toxic effects of penconazole on crayfish (Astacus leptodactylus), which is a bioindicator in freshwater ecosystems and consumed economically, are not known. Therefore, in this study, the purpose was to contribute to the literature on the potential harmful effects of penconazole on a non-target species, Astacus leptodactylus. For this aim, the acute toxicity (96 h) of penconazole was examined. The 96-h LC50 value of penconazole was detected as 18.7 mg L−1. Four concentrations of penconazole (18.7 mg L−1, 9.35 mg L−1, 4.68 mg L−1, 2.34 mg L−1) were applied to crayfish for 96 h. The results showed that penconazole had destructive effects on esterase mechanisms by inhibiting acetylcholinesterase (AChE) and carboxylesterase (CaE) activities. Significant increases were observed in all antioxidant parameters (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), reduced glutathione (GSH), malondialdehyde (MDA)) in all doses except the lowest concentration (2.34 mg L−1). All adenosine triphosphatase (ATPase) activities (Na+/K+-ATPase, Mg2+-ATPase, Ca2+-ATPase, total ATPase) had significant dose-related inhibition in both gill and muscle tissues. In summary, our findings show that acute penconazole administration to crayfish causes significant toxic effects on esterase, antioxidative parameters, and metabolic enzymes.
Acrylamide (ACR), a ubiquitous agent, has various chemical and industrial applications, and it is found in backed or fried carbohydrate-rich food. It has been related to multiple toxicological effects, and it causes high cytotoxicity through oxidative stress. The present study aimed to investigate the potential effect of ACR toxicity administered at different concentrations (5, 10, and 20 mg/L), during 5 days, in order to evaluate the fatty acid (FA) composition and redox state in the digestive gland of Mactra corallina. The results showed, in ACR-treated clams, a significant increase in malondialdehyde, hydrogen peroxide, protein carbonyl, and metallothionein levels, as well as an alteration of the enzymatic (superoxide dismutase, glutathione peroxidase, and catalase) and non-enzymatic (reduced glutathione and ascorbic acid) antioxidant status. However, acetylcholinesterase activity was inhibited in a concentration-dependent manner. In our experiment, the n-3 (Omega-3) and n-6 (Omega-6) polyunsaturated fatty acid levels were significantly changed in all ACR-treated groups. A decrease in eicosapentaenoic acid (C20:5n-3, EPA) and docosahexaenoic acid (C22:6n-3, DHA) was observed in 10-mg/L and 20-mg/L ACR-treated groups. Nevertheless, arachidonic acid (C20:4n-6, ARA) and its precursor linoleic acid (C18:2n-6, LA) were increased. Besides oxidative stress parameters, FA composition may be an additional tool for assessing ACR contamination.
Invertebrates represent a large proportion of the biomass in aquatic ecosystems, particularly in the ocean. In recent years, invertebrates have been well-consolidated models in evolutionary developmental biology research and, consequently, genomic and transcriptomic sequence databases from a plethora of species across the animal kingdom have become available. This has provided an excellent source of evidence confirming that invertebrates operate endogenous mechanisms for PUFA production. The present paper reviews the current knowledge of gene complement and, where possible, the function of desaturases and elongases with pivotal roles in PUFA biosynthesis of aquatic invertebrates. More specifically, this review covers three major enzyme types, namely ωx desaturases, front-end desaturases and elongases, that have been characterised from species of sponges, cnidarians, molluscs, annelids, crustaceans, rotifers, echinoderms and non-vertebrate chordates (amphioxus and sea squirt). These studies have shown that invertebrates operate alternative and unusual pathways of PUFA biosynthesis involving gene families with complex phylogeny and functional diversity. Consequently, research in this area provides potentially valuable molecular tools in the form of genes that can be used in the biotechnological production of n-3 products.
Several environmental contaminants including toxic trace metals are being discharged into the coastal environment causing serious threat to marine organisms and posing public health risk. Marine bivalves (mussel, oyster, and clam) have been successfully used as sentinel organisms for monitoring contaminant levels, including trace metals, in coastal waters around the globe. Chemical analyses measure the contaminants present in the biota but do not necessarily reveal potential biological efects. Therefore, the need to detect and assess the efects of contaminants, especially at low concentrations, has led to the development of molecular markers of contaminant efects called biomarkers. Owing to their short time of response, biomarkers in marine bivalves are used as early warning signals of biological efects caused by environmental pollutants. Research into the development and application of accurate biomarker-based monitoring tools for the environmental contaminants has been intensiied in several developed countries.
The use of commercial pesticides combinations increases the risk of intoxication in non-target aquatic organisms. Here, we investigate the potential of a commercial pesticide formulation containing (CYP) plus chlopyrifos (CPF) to induce oxidative damage on two fish species (common carp and zebrafish). Carp and zebrafish were exposed for 96 h under laboratory conditions. Fish were divided in three different groups: CTL, 0.3 μg L-1or 0.6 μg L-1of CYP and 0.5 or 1 μg L-1of CPF in commercial formulation. Both carp and zebrafish showed an increase in lipid peroxidation (LPO) and glutathione-S-transferase (GST) activity when compared to control group. Other oxidative parameters responded differently to exposure in carp and zebrafish. There were an increase in ascorbic acid (ASA) levels and decrease in catalase (CAT) activity and non-protein thiols (NPSH) levels in treated groups of carps. In the other hand, zebrafish showed significant decrease in ASA and increase in CAT activity and NPSH levels. Overall, we demonstrate noxious effects on redox parameters in two fish experimental models and different effects were observe in each fish species exposed to commercial pesticide formulation. This difference responses observed can be related with specific mechanisms of detoxification and antioxidant defense system of each species.
Lipids are a fundamental class of organic molecules implicated in a wide range of biological processes related to their structural diversity, and based on this can be broadly classified into five categories; fatty acids, triacylglycerols (TAGs), phospholipids, sterol lipids and sphingolipids. Different lipid classes play major roles in neuronal cell populations; they can be used as energy substrates, act as building blocks for cellular structural machinery, serve as bioactive molecules, or a combination of each. In amyotrophic lateral sclerosis (ALS), dysfunctions in lipid metabolism and function have been identified as potential drivers of pathogenesis. In particular, aberrant lipid metabolism is proposed to underlie denervation of neuromuscular junctions, mitochondrial dysfunction, excitotoxicity, impaired neuronal transport, cytoskeletal defects, inflammation and reduced neurotransmitter release. Here we review current knowledge of the roles of lipid metabolism and function in the CNS and discuss how modulating these pathways may offer novel therapeutic options for treating ALS.
Pyriproxyfen (2-[1-methyl-2-(4-phenoxyphenoxy) ethoxy] pyridine) (PPF), is a pyridine-based pesticide widely used to control agricultural insect pests and mosquitoes in drinking water sources. However, its ecotoxicological data is limited in aquatic vertebrates particularly in fish. Hence, the present study aimed to evaluate the adverse effect of PPF in zebrafish embryo development (Danio rerio). In order to investigate the impact of PPF, embryos were exposed to 0.16, 0.33 and 1.66 μg/mL (0.52, 1.04 and 5.2 μM, respectively) for 96 hpf and various biomarker indices such as developmental toxicity (edema formation, hyperemia, heart rate and scoliosis), oxidative stress (reactive oxygen species (ROS), lipid peroxidation (LPO) and nitric oxide (NO)), antioxidant responses (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx) and reduced glutathione (GSH)), biochemical (lactate dehydrogenase (LDH) and acid phosphatase (AP)), neurotoxicity (acetylcholinesterase (AChE)), genotoxicity (apoptosis and DNA damage) and histopathological changes were determined. The results showed that severe developmental deformities and changes in heart rate were observed in embryos treated with highest (1.66 μg/mL) concentration than the control (P < 0.05). Heart size measurement showed that, significant change in heart size (P < 0.01) was observed in embryos of 96 hpf only at 1.66 μg/mL PPF exposure. The oxidative stress was apparent at highest test concentration (1.66 μg/mL) as reflected by the elevated ROS, LPO and NO and changes in antioxidant enzyme activities including SOD, CAT, GST and GPx (P < 0.05). Besides, GSH level and AChE activity were significantly lowered in 1.66 μg/mL PPF exposed group than the control. After 96 hpf of PPF exposure, no significant changes were found in AP activity whereas, a biphasic response was observed in he LDH activity. There was no genotoxic effect in embryos exposed to PPF at 0.16 and 0.33 μg/mL, while significant (P < 0.05) DNA damage and apoptosis were found in 1.66 μg/mL treated group. Histopathological analysis revealed that exposure to PPF at 1.66 μg/mL resulted in thinning of heart muscles, pericardial edema and hyperemia while there was no obvious changes were observed in other treatment groups. Hence, the results of the present study demonstrate that PPF could cause adverse effect on early developmental stages of zebrafish at higher concentration.
Ultraviolet B (UV-B) radiation is environmental stressors with detrimental effects on many aquatic organisms including fish. In addition, UV-B exposure combined with other environmental factors could have even higher negative effects. The purpose of the study was to investigate the effect of UV-B radiation exposure on zebrafish embryos/larvae in terms of survival, developmental toxicity and the mRNA levels of the genes related to oxidative stress and innate immune response under different temperatures (24°C, 28°C and 30°C). Zebrafish embryos were exposed to 3.3 Wm-2 UV-B radiation and/or 24°C, 28°C (for control) and 30°C temperatures between 4 and 96 h post-fertilization. Mortality, Hatching rate, malformations and heartbeat rate were evaluated. The results demonstrated that UV-B exposure or different temperatures (24°C and 30°C) induced developmental toxicity, including delayed hatching, increased occurrence of malformations, and reduced heartbeat rate and survival. The combined exposure to UV-B and different temperatures (24°C and 30°C) resulted in greater adverse effects on embryonic development. Furthermore, RT-PCR results showed that the mRNA levels of superoxide dismutase 1 (sod1), catalase 1 (cat1), heat shock protein 70 (hsp70), interleukin-1 beta (il-1β) and tumor necrosis factor alpha (tnfα) genes were significantly up-regulated at all of the treatment groups. These results revealed that the interaction between UV-B and temperature impaired the development of zebrafish embryos and disrupted their metabolism.
Concentrations of heavy metals (Cu, Ni, Zn, Cd and Pb) were measured in sediments, water and liver and kidney tissues of three Indian major carps (Labeo rohita, Catla catla and Cirrhinus cirrhosus), belonging to two different weight groups (250 and 500 g), collected from ponds at two different sites (Nalban bheri and Diamond Harbour). The tissues were analysed for the levels of different antioxidant defence systems such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GRd), glutathione S-transferase (GST), glutathione (GSH) and malondialdehyde (MDA). Concentrations of all the metals were significantly higher (P < 0.05) in sediment, water and the tissues from Nalban bheri compared to those in Diamond Harbour. Metal concentrations were the lowest in C. cirrhosus, which increased with an increase in fish weight, and the liver accumulated higher amount of metals than the kidney. Activities of all enzymatic and non-enzymatic antioxidant parameters except GPx and GRd were significantly higher (P < 0.05) in the tissues from Nalban bheri than those in Diamond Harbour. Significant multicollinearity was found in the values of SOD, CAT, GST, GRd, GPx and MDA with Pb, Cu and Ni in all three fish species at Nalban and with Cd in L. rohita and C. catla. Principal component analysis results revealed that stress response in a polluted site was directly regulated by an amalgamation of GSH profile and the levels of MDA in a synchronized manner. The study indicated a tissue-specific and species-specific difference for heavy metal-induced oxidative stress response in fish and a correlation between different heavy metals and individual oxidative stress markers.
Pesticides exposure causes usually harmful effects to the environment and human health. The present study aimed to investigate the potential toxic effects of penconazole, a triazole fungicide, on the cerebrum and cerebellum of adult rats. Penconazole was administered intraperitoneally to male Wistar rats at a dose of 67 mg kg⁻¹ body weight every 2 days during 9 days. Results showed that penconazole induced oxidative stress in rat cerebrum and cerebellum tissues. In fact, we have found a significant increase in malondialdehyde, hydrogen peroxide, and advanced oxidation protein product levels, as well as an alteration of the antioxidant status, enzymatic (superoxide dismutase and catalase) and nonenzymatic (glutathione), the cholinergic function, and membrane-bound ATPases (Na⁺/K⁺-ATPase and Mg²⁺-ATPase). Penconazole also provoked histological alterations marked by pyknotic and vacuolated neurons in the cerebrum and apoptosis and edema in the cerebellum Purkinje cells’ layer. Therefore, the use of this neurotoxicant fungicide must be regularly monitored in the environment.
Background: Use of pesticides in agricultural fields has a series of toxicological and environmental problems. Methyl parathion (MP), an organophosphorus (OP) insecticide is a widely used pesticide and is highly toxic to non-target organisms. Fish has been used as indicator species for monitoring of pollution in the aquatic environment. Catla catla an Indian major carp is an edible fish and is highly sensitive to slight stress. Recently, fish biomarkers are widely used to determine the internal and external health status caused by chemicals.
Results: C. catla were exposed to acute (0.09 ppm) and sublethal (0.009 ppm) concentrations of MP to determine the alterations in antioxidant and metabolic enzyme activities in blood plasma and tissues (gill and liver). Intoxication with MP resulted in induction of oxidative stress which implies that fish utilizes enzymatic mechanisms to tolerate the effects caused by generated ROS due to MP accumulation. Significant alterations in GOT and GPT activity in plasma and tissues during acute as well as sublethal exposure might have resulted from the organal damage. The significant increase of LDH activity indicates severe cellular damage in organ/tissues of MP treated fish.
Conclusion: The results of the present investigation suggest that gill is the most sensitive organ to MP toxicity. The alterations of the enzymatic parameters can be effectively used as potential biomarkers for monitoring of the organophosphorus pesticides in aquatic environment. Further, MP should be used with caution in order to protect natural waters and aquatic organisms.
In this work, the effects of penconazole and triadimenol to protein amount and growth of the microalgae Scenedesmus acutus were investigated. The culture of S. acutus was exposed to dissimilar concentrations of penconazole and triadimenol (1, 3, 6, 10 and 15 μg/L) in the climate chamber at 23 ± 1°C and 16:8 photoperiod. Cell numbers and growth rates in liquid cultures of S. acutus were calculated for a period of four days. The results indicated toxic effects of penconazole and triadimenol on growth and protein amount of S. acutus. The protein amount and cell number of S. acutus in cultures treated with penconazole and triadimenol were rapidly decreasing at second day.
We have different possibilities and tools to assess the impact of pollution on marine ecosystems. The ecotoxicological approaches are based on the use of biomonitors and biomarkers. They aim to study the effect of toxic chemicals on the biological organisms especially at the population, community and ecosystem levels. The ultimate goal of ecotoxicology is to be able to predict the effects of pollution so that the most efficient and effective action to prevent or remediate any detrimental effect. In order to assess the impact of anthropogenic activities on the aquatic ecosystem and to insure compliance with regulation or guidelines, we use biomonitoring. This kind of approach is based on the use of biological responses in order to assess anthropogenic changes in the environment. Biomonitoring involves the use of indicator species such as filter feeding mollusk bivalves. These organisms tend to accumulate pollutants in their tissues without showing any apparent detrimental effect. Moreover, they could reflect the real bio available fraction of the pollutant. In order to have an early warning system predicting the pollution effects even at low levels, biomarkers were extensively studied. Some of them were validated in both field and in vivo conditions. In the present paper, the usefulness of bioindicators and biomarkers in pollution monitoring are discussed. An overview of results from case studies dealing with in situ, in vivo and transplantation experiments is presented.
Dimethoate is a broad-spectrum organophosphate insecticide and acaricide. Through various pathways, such as
runoff and drift, dimethoate can reach marine environment, and easily impact common organisms in coastal
areas, close to agriculture lands, namely crustaceans. The purpose of this study was to investigate the potential
effects of dimethoate exposure (50, 100, and 200
μ
g/l), for 1 day, on a wide range of markers of oxidative stress
and neurotransmission impairment, as well as fatty acids composition and histopathological aspect in the gills of
the green crab Carcinus aestuarii. A significant increase in n-3 polyunsaturated fatty acids series, namely the
eicosapentaenoic acid (C20: 5n3) and its precursor alpha-linolenic acid (C 18: 3n3) in dimethoate-treated crabs
was recorded. Concerning n-6 polyunsaturated fatty acids, we noted a high reduction in arachidonic acid
(C20:4n-6) levels. Dimethoate exposure increased the levels of hydrogen peroxide, malondialdehyde, lipid hy
droperoxides, protein carbonyl, and caused the advanced oxidation of protein products along with enzymatic and
non-enzymatic antioxidant-related markers. Acetylcholinesterase activity was highly inhibited following expo
sure to dimethoate in a concentration-dependent manner. Finally, deleterious histopathological changes with
several abnormalities were noted in exposed animals confirming our biochemical findings. The present study
offered unique insights to establish a relationship between redox status and alterations in fatty acid composition,
allowing a better understanding of dimethoate-triggered toxicity.
Lambda-cyhalothrin (λ-cyh) is a potential pyrethroid insecticide widely used in pest control. The presence of pyrethroids in the aquatic ecosystem may induce adverse effects on non-target organisms such as the sea urchin. This study was conducted to assess the toxic effects of λ-cyh on the fatty acid profiles, redox status, and histopathological aspects of Paracentrotus lividus gonads following exposure to three concentrations of λ-cyh (100, 250 and 500 µg/L) for 72 h. The results showed a significant decrease in saturated fatty acid (SFAs) with an increase in monounsaturated fatty acid (MUFAs) and polyunsaturated fatty acid (PUFAs) levels in λ-cyh treated sea urchins. The highest levels in PUFAs were recorded in the eicosapentaenoic acids (C20:5n-3), docosahexaenoic acids (C22:6n-3) and arachidonic acids (C20:4n-6) levels. The λ-cyh intoxication promoted oxidative stress with an increase in hydrogen peroxide (H2O2), malondialdehyde (MDA) and advanced oxidation protein products (AOPP) levels. Furthermore, the enzymatic activities and non-enzymatic antioxidants levels were enhanced in all exposed sea urchins, while the vitamin C levels were decreased in 100 and 500 µg/L treated groups. Our biochemical results have been confirmed by the histopathological observations. Collectively, our findings offered valuable insights into the importance of assessing fatty acids’ profiles as a relevant tool in aquatic ecotoxicological studies.
Toll‐like receptor 4 (TLR4) and TLR2 were shown to be activated by saturated fatty acids (SFAs) but inhibited by docosahexaenoic acid (DHA). However, one report (ATVB 11:1944, 2009) suggested that SFA‐induced TLR activation in cell culture systems is due to contaminants in BSA used for conjugating fatty acids. This report casted doubt about proinflammatory effects of SFAs. Our studies herein demonstrate that sodium palmitate (C16:0) or laurate (C12:0) without BSA conjugation induced phosphorylation of IκBα, JNK, ERK, and NFκB p65 and TLR target gene expression in THP1 monocytes or RAW264.7 macrophages, respectively when cultured in low FBS (0.25%) medium. C12:0 induced NFκB activation through TLR2 dimerized with TLR1 or TLR6, and through TLR4. Since BSA was not used in these experiments, contaminants in BSA have no relevance. Unlike suspension cells (THP‐1), BSA conjugation is required for C16:0 to induce TLR target gene expression in adherent cells (RAW264.7). BSA‐conjugated C16:0 transactivated TLR2 dimerized with TLR1 or TLR6, and through TLR4 as seen with C12:0. These results and additional studies with LPS sequester polymixin B and MyD88−/− macrophages indicated that SFA‐induced activation of TLR2 or TLR4 is a fatty acid‐specific effect, but not due to contaminants in BSA or fatty acid preparations. (USDA‐ARS‐WHNRC Program Funds and NIHDK 064007)
Lambda-cyhalothrin (λ-cyh), a synthetic pyrethroid type II, is one of the most toxic xenobiotics to aquatic organisms, which leads to a number of complex toxicological syndromes. The present study aimed to assess the adverse effects of λ-cyh, on fatty acid (FA) composition, redox status, and the histopathology aspect of Venus verrucosa digestive gland under an exposure to a series of concentrations (100, 250 and 500 µg/L). An increase of saturated fatty acid (SFAs) levels and a decrease of polyunsaturated fatty acids (PUFAs) content, mainly eicosapentaenoic (C20: 5n − 3, EPA) and docosahexaenoic (C22: 6n − 3, DHA) acids, were observed in λ-cyh-treated digestive gland. Moreover, our data indicated an alteration in arachidonic acid (C20:4n − 6, ARA) level. The exposure to the highest dose of λ-cyh promoted oxidative stress with an increase of malondialdehyde (MDA), advanced oxidation protein product (AOPP), metallothionein (MT) and hydrogen peroxide (H2O2) levels. A significant decrease in enzymatic (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) and non-enzymatic (reduced glutathione (GSH), vitamin C and non-protein-SH (NPSH)) antioxidants was showed in treated groups. Moreover, acetylcholinesterase (AChE) activity was inhibited with the increase in λ-cyh concentration. Our biochemicals results have been confirmed by the histopathological observations. Overall, our results indicated the toxic effect of λ-cyh on the redox status of V. verrucosa digestive gland and highlighted the usefulness of determining FA composition in the better understanding of λ-cyh toxicity.
Graphene oxide (GO) was chemically modified by bis(2-pyridylmethyl)amino groups (BPED) through a multistep procedure. For comparison, and to justify the grafting of BPED groups onto the GO sheets, the GO-based material obtained after each step was used as a solid phase adsorbent for removing Cu(II), Ni(II) and Co(II) metal ions from aqueous solutions. The influence of metal ion concentrations, pH, contact time and temperature on their adsorption onto the GO-based adsorbents was investigated and the GO-EDA-CAC-BPED adsorbent showed the highest ability to adsorb Cu(II), Ni(II) and Co(II) with a concentration of 250 mg.L-1 at pH = 7. Additionally, it was demonstrated that the equilibrium adsorption capacities of these metal ions followed the order of Cu(II)>Ni(II)>Co(II) whatever the GO-based adsorbent. Moreover, to examine the underlying mechanism of the adsorption process, pseudo-first order, pseudo-second order, Elovich or Roginsky-Zeldovich and intraparticle diffusion models were fitted to experimental kinetic data. It was shown that the pseudo-second-order model was the most appropriate one to describe the adsorption of heavy metal ions by the GO-based materials. Finally, it was demonstrated that their desorption/regeneration capacities were higher than 10 cycles, opening the path to the removal of metal ions from wastewater solutions.
Penconazole is a typical triazole fungicide with wide use on fruits, vegetables, and tea plants to control powdery mildew. In the present study, an efficient graphite carbon black solid phase extraction (GCB-SPE) purification combined with chiral ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for determination of penconazole enantiomers in different complex matrices, including grape, tea, soil, lotus root, lotus leaf, lotus seed and hulls. The method was then applied to investigate the enantioselective dissipation of penconazole enantiomers in a real field experiment of grape and soil. As a result, a satisfactory separation of penconazole enantiomers on a chiral Lux Cellulose-2 column (150 mm × 2 mm i.d., 3 µm) was obtained with 0.1% formic acid in methanol and 10 mmol L ⁻¹ ammonium acetate in water (75/25, v/v) as mobile phase at 0.25 mL min ⁻¹ . The enantiomer (+)-penconazole was firstly eluted, and (-)-penconazole was then eluted. The method showed reliable performances in linearity, recovery and precision, the recoveries of (+)-penconazole and (-)-penconazole in all of six matrices were between 70.5% and 121.0% with the relative standard deviations (RSDs) ranging from 0.8% to 23.6% at the low, medium and high spiked levels. The limits of quantitation (LOQs) of this method were lower than 0.0025 mg kg ⁻¹ in grape, soil and lotus root, 0.005 mg kg ⁻¹ in lotus leaf, lotus seed meat and lotus seed shell, and 0.0125 mg kg ⁻¹ in tea. Results of field trials indicated that (-)-penconazole degraded faster than its (+)-isomer in grape. While only a moderate stereoselectivity was observed in soil, with (-)-penconazole preferential degraded. The proposed method could be used to investigate enantioselective environmental behavior of penconazole enantiomers in complex matrices. And results in this study could provide useful information on realistic risk assessment of penconazole in grape.
S-metolachlor (SMOC) and terbuthylazine (TBA) are herbicides that commonly appear as active ingredients (a.i.) in the composition of plant protection products. In a previous work, experimental bioassays were performed using those chemicals to find suitable molecular biomarkers to assess its toxicity to the non-target species Scrobicularia plana. The results obtained showed that the pollutants produce mortality and biochemical changes at the species, namely in protein contents and enzymatic activity levels. Thus, for a better understanding of the total biochemical impacts of those pollutants in S. plana, the composition of fatty acids (FA) and carbohydrates (CH) of the survival organisms are investigated here. In addition, since this species is edible its biochemical profile is directly related to its nutritious quality, which is analysed in this study. Furthermore, the analyses were performed in two types of tissue-the muscle and visceral mass of each survival organism. The greatest changes in FA composition are observable in small size class, being the most sensitive size class both at the toxicological and biochemical level. FA contents are higher in small organisms, both at the field and under laboratory conditions, being the disparity between size classes higher in visceral masses than in muscles. Indeed, muscles adequately represent the FA profile since those molecules appear in higher content in this tissue compared to visceral masses, becoming the better indicator tissue of biochemical changes. Besides, using muscles, less amount of biomass is needed, so it turns out to be the most cost-effective tissue to be used as endpoint in future studies. FA profiles observed at SMOC and TBA exposure are different, organisms from TBA exposure presenting a lower nutritious quality, in terms of FA abundance and diversity, than the organisms exposed to SMOC. Still, SMOC produces reductions of HUFA, essential fatty acids that cannot be synthesized by the species. Moreover, HUFA (mostly EPA and DHA) occupied the greatest part of the FA composition of organisms exposed to the control treatments and to TBA; however, the decreases of HUFA caused by the SMOC exposure change the profiles and make SFA the most dominant group. These findings represent a risk of low occurrence of essential fatty acids in entire aquatic environments exposed to the chemicals studied. Regarding CH, glucose is the only monosaccharide found in S. plana which was expected since glycogen is the main polysaccharide in animal tissues. In general, the glucose content increases with a concentration of pollutants, whereas the glycogen concentration decreases, suggesting that the glucose is being released as a response to chemical stress. Thus, this work presents tools to assess biochemical impacts of S-me-tolachlor and terbuthylazine in aquatic systems and to goes deeper in the knowledge of these pollutants' toxicity to non-target species to predict its propagation through aquatic trophic webs.
https://authors.elsevier.com/c/1YZunXad0S0R0
In the present study, sub-lethal effects of chlorpyrifos, alone (25 and 50 μg L⁻¹) and in combination with Polyethylene glycol (5 and 10 mg L⁻¹), on common carp were investigated. Exposure to chlorpyrifos caused significant changes in all blood biochemical parameters compared to control groups. Total protein, triglyceride, glucose levels, as well as lactate dehydrogenase (LDH), gamma-glutamyl transferase (GGT), and creatine phosphokinase (CPK) activities in plasma changed after exposure to 10 mg L⁻¹ polyethylene glycol (PEG), while fish exposed to PEG did not show any significant difference in aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and acetylcholinesterase (AChE) activities and albumin and globulins levels. Exposure to a combination of chlorpyrifos and PEG caused a significant change in AST, GGT, CPK, LDH and AChE activity, total protein and glucose level. The influence of chlorpyrifos and PEG combination on ALP, cholesterol, triglyceride, albumin, and globulin depends on the concentration of the insecticide and PEG. With a reduction in chlorpyrifos concentration, PEG can maintain ALP activity and albumin at a normal level. Although fish exposure to chlorpyrifos, alone or in combination with polyethylene glycol, significantly increased malondialdehyde (MDA) and catalase (CAT) level, it decreased total antioxidant level (TAN). Exposure to just polyethylene glycol had no impact on CAT activity, TAN and MDA level. According to the results, PEG can have an antagonistic effect on chlorpyrifos toxicity, depending on these two materials concentration. However, chlorpyrifos increased the toxicity of PEG.
Penconazole (PEN) is a fungicide used in agriculture. The aim of this work was to evaluate the exposure to PEN in vineyard workers focusing on urinary biomarkers.
Twenty-two agricultural workers were involved in the study; they were investigated during PEN applications and re-entry work, performed for 1–4 consecutive working days, for a total of 42 mixing and applications and 12 re-entries. Potential and actual dermal exposure, including hand exposure, were measured using pads and hand washes. Urine samples were collected starting before the first application, continuing during the work shift, and ending 48 h after the last shift. The determination of PEN in dermal samples and PEN metabolites in urine was performed by liquid chromatography tandem mass spectrometry.
Dermal potential body exposure and actual total exposure showed median levels ranging from 18 to 3356 µg and from 21 to 111 µg, respectively. Urinary monohydroxyl-derivative PEN-OH was the most abundant metabolite; its excretion rate peaked within 24 h after the work shift. In this period, median concentrations of PEN-OH and the carboxyl-derivative PEN-COOH ranged from 15.6 to 27.6 µg/L and from 2.5 to 10.2 µg/L, respectively. The concentration of PEN-OH during the work shift, in the 24 h after and in the 25–48 h after the work shift were correlated with actual body and total dermal exposure (Pearson's r from 0.279 to 0.562).
Our results suggest that PEN-OH in the 24 h post-exposure urine is a promising candidate for biomonitoring PEN exposure in agricultural workers.
This study evaluated the toxic effects and recovery patterns in zebrafish (Danio rerio) after exposure to phosalone-based (PBP) and cypermethrin-based (CBP) pesticides. Initially, the 96 h LC50 values of the pesticides were calculated as being 5.35 µg of active ingredient (AI) L-1 for CBP and 217 µg AI L-1 for PBP based on measured concentrations. Accordingly, experimental groups were exposed to three sublethal concentrations of pesticides for 96 h, separately, and then zebrafish were transferred to pesticide-free conditions for 10 and 20 days recovery periods. Biochemical markers were assessed including carboxylesterase (CaE), acetylcholinesterase (AChE), glutathione S-transferase (GST), lactate dehydrogenase, glutathione peroxidase, catalase, alanine and aspartate aminotransferase (ALT, AST) activities after the exposure and recovery periods. Also, the pesticide concentrations in test water were quantified by high-performance liquid chromatography (HPLC) analysis. Our results showed that AChE and CaE activities were significantly inhibited and GST was induced by both pesticides after 96 h exposure. For PBP exposure, the decreases for GST induction and CaE inhibition showed a partial recovery in pesticide-free conditions. However, the decreases in AChE activity for CBP exposure and insufficient increases in same enzyme activity for PBP exposure after 20 days in pesticide-free conditions indicated that the projected recovery period was not enough to the recovery of AChE activities and for the improvement of fish health.
Quantitative analysis of the histopathological and immune parameters of bivalve Modiolus kurilensis collected from water areas with different level of ecotoxicological stress was performed. Significant differences between samples from polluted and non-polluted sites were revealed for total haemocyte count; percentage of agranulocytes; size and internal complexity of agranulocytes and granulocytes; phagocytic activity; percentage of NBT-positive cells; haemolytic activity and plasma protein concentration; percentage of the optical density of haemolymph major polypeptide bands at 55kDa, 78kDa, and 124kDa; concretion coverage area in the kidney tubules; thickness of the tubular basement membrane; nephrocyte shape; and karyopyknosis of the kidneys; and hypervacuolisation; necrosis; karyopyknosis; haemocyte infiltration; fibrosis; and invasion of the digestive gland. Analysis of the global histopathological condition index based on the weighted indices also revealed that both the digestive gland and kidneys showed significantly greater histopathological changes in the bivalves collected from polluted water. Bivalve histopathology is an established tool in aquatic toxicology. However, it reflects a morphological picture of change, which, as a rule, can be clearly recorded only at the later stages of pathology, and in some cases, indicates an adaptation to stressors within the physiological norm. In this respect, a promising and highly sensitive biomarker of the functional state of bivalves, in terms of norm and pathology as well as their habitat, is the evaluation of immune status in combination with morphological changes. However, the use of different methods and scales of assessment and the diagnosis of biomarkers, characterised by different profiles of the stress response, makes it difficult to compare the results of different studies. We propose a reliable and powerful system for assessing the physiological state of bivalve molluscs, expressed in the integral health index (IHI) and based on the standardisation of the numerical values for all parameters that have significant differences between animals collected from impacted and non-impacted water areas. In our study, IHI calculated in three variants (for histopathological parameters, for immunological parameters, and in combination) showed the most significant differences in each of the cases, but the strongest difference (-4.07) was in calculating the total IHI, which included both the immune and histopathological parameters (p = 0.00005).
At the past 30 years were recorded an intensive practice in the use of fertilizers and pesticides, mainly in the European Mediterranean region, that, in particular cases, exceeded the limits of regular legislations established by the European Union. The widespread use of these chemicals compounds and the pressure over agricultural fields near valuable ecologically coastal areas conducted to the implementation of monitoring plans to the recovering of aquatic ecosystems. Since the 80′s Mondego estuary (Figueira da Foz, Portugal) has been harassed by anthropogenic pressures, which triggered the implementation of mitigation monitoring programs at the last 18 years, allowing its recovery. Copper sulphate is used in industrial activities, but also it is much used in pesticides formulations, with application in agricultural activities, namely in rice farms to control pests. Studies reported that copper may affect biochemical processes, such lipid metabolism of some organisms, although specific changes in fatty acid (FA) profiles are still unknown. Nowadays, bivalve species are used in ecotoxicological bioassays due some particular characteristics, such as the wide distribution, ecological relevance, the capacity to filter and ingest large volumes of sediment particles and water and ease handling in the field and in the laboratory. Therefore, this work aims to determine toxic effects and changes in fatty acids profile composition of the two marine bivalve species Cerastoderma edule and Scrobicularia plana when exposed to copper sulphate, considering small (medium body size = 1.97 cm and 3.47 cm, respectively) and big (medium body size = 2.45 cm and 4.20 cm, respectively) size classes. In a first phase organisms were exposed under laboratorial conditions to copper sulphate to determine lethal concentration; at a second phase, it was compared the FA profile and the nutritive quality of both species and size classes at the field and in the lab. Our results state C. edule is more sensitive to copper sulphate (LC50 = 0.818 (0.595–0.987) mg/L; 1.129 (0.968–1.289) mg/L, to big and small organisms, respectively) than S. plana (LC50 = 2.563 (2.229–2.903) mg/L; 4.705 (3.540–12.292) mg/L, to big and small organisms, respectively). Furthermore the last one presents greater abundance and variety of FA and essential fatty acids (EFA), namely DHA and EPA, rates than C. edule. Still, big size class of both bivalve species is the most affected by the contaminant.
Although the toxicity of beta-cypermethrin (beta-CYP) to aquatic organisms has become a significant concern in recent years, its enantioselective effects on non-target organisms is poorly understood. To investigate the enantioselective toxicity of beta-CYP on zebrafish, adult zebrafish were exposed to a series of isometric concentrations of four beta-CYP enantiomers and the beta-CYP racemate for 96 h. In addition, the activities of four antioxidant enzymes and the malondialdehyde (MDA) content in zebrafish liver and brain were tested after 15 and 30 days beta-CYP enantiomers and racemate exposure under environmentally relevant dosages (0.01 and 0.1 μg/L). According to the acute toxicity results, the 1R-cis-αS and 1R-trans-αS enantiomers were more lethal than 1S-cis-αR and 1S-trans-αR. At 0.1 μg/L, the 1R-cis-αS and 1R-trans-αS enantiomers, and the beta-CYP racemate could significantly induce a hepatic MDA content at 30 days post exposure (dpe), while only 1R-cis-αS caused brain lipid peroxidation. An apparent regulation of antioxidase levels was observed in zebrafish liver and brain after exposure to the 1R-cis-αS and 1R-trans-αS enantiomers, and the beta-CYP racemate. In contrast, no significant oxidative stress was observed in zebrafish exposed to 1S-cis-αR and 1S-trans-αR enantiomers under the test concentrations. This work demonstrated the occurrence of enantioselectivity in toxicity and oxidative stress of beta-CYP to adult zebrafish, which should be considered in environmental risk assessments.
Research on the biochemistry and molecular biology of lipids and lipoproteins has experienced remarkable growth in the past 20 years, particularly with the realization that many different classes of lipids play fundamental roles in diseases such as heart disease, obesity, diabetes, cancer and neurodegenerative disorders. The 5th edition of this book has been written with two major objectives. The first objective is to provide students and teachers with an advanced up-to-date textbook covering the major areas of current interest in the lipid field. The chapters are written for students and researchers familiar with the general concepts of lipid metabolism but who wish to expand their knowledge in this area. The second objective is to provide a text for scientists who are about to enter the field of lipids, lipoproteins and membranes and who wish to learn more about this area of research. All of the chapters have been extensively updated since the 4th edition appeared in 2002. Key Features: * Represents a bridge between the superficial coverage of the lipid field found in basic biochemistry text books and the highly specialized material contained in scientific review articles and monographs. * Allows scientists to become familiar with recent developments related to their own research interests, and will help clinical researchers and medical students keep abreast of developments in basic science that are important for subsequent clinical advances. * Serves as a general reference book for scientists studying lipids, lipoproteins and membranes and as an advanced and up-to-date textbook for teachers and students who are familiar with the basic concepts of lipid biochemistry.
Penconazole is a systemic fungicide commonly used in agriculture as the commercial preparation Topas. Although triazole fungicides are widely found in the aquatic environment, little is known about their acute toxicity on fish. In this study we assessed the effects of short-term exposure to Topas on some parameters of homeostasis of reactive oxygen species (ROS), such as the levels of markers of oxidative stress and parameters of the antioxidant defense system of goldfish (Carassius auratus L.). Gills appeared to be the main target organ of Topas toxicity, showing the greatest number of parameters affected. Gills of Topas-treated fish showed a higher content of low (L-SH) and high (H-SH) molecular mass thiols and higher activities of superoxide dismutase (SOD), catalase, glutathione reductase (GR), glutathione-S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PDH) as well as reduced carbonyl protein content (CP), as compared with those in the control group. In the liver, goldfish exposure to 15-25mgL(-1) Topas resulted in a higher L-SH and H-SH content, but lower CP levels and activity of GST. In kidney, Topas exposure resulted in higher activities of glutathione peroxidase (GPx) and G6PDH, but lower L-SH content and activity of GST. The results of this study indicate that acute goldfish exposure to the triazole fungicide Topas increased efficiency of the antioxidant system in fish gills, liver, and kidney. This could indicate the development of low intensity oxidative stress which up-regulates defense mechanisms responsible for protection of goldfish against deleterious ROS effects.
The aim of this study was to investigate the combined effects of temperature and metal contamination (cadmium and nickel) on phospholipid fatty acid composition, antioxidant enzyme activities and lipid peroxidation in fish. Yellow perch were acclimated to two different temperatures (9 °C and 28 °C) and exposed either to Cd or Ni (respectively 4 μg/L and 600 μg/L) for seven weeks. Superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase activities and glutathione concentration were measured as indicators of antioxidant capacities, while malondialdehyde concentration was used as an indicator of lipid peroxidation. Poikilotherms including fish counteract the effects of temperature on phospholipid fatty acid ordering by remodelling their composition to maintain optimal fluidity. Accordingly, in our study, the fatty acid composition of yellow perch muscle at 9 °C was enhanced in monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) compared to fish maintained at 28 °C, in agreement with the theory of homeoviscous adaptation. Using ratios of various fatty acids as surrogates for desaturase and elongase activities, our data suggests that modification of the activity of these enzymes is responsible for the thermal acclimation of phospholipid fatty acid profiles. However, this response was altered under Ni and Cd exposure: PUFA decreased (specifically n-6 PUFA) while the proportion of saturated fatty acids increased at 9 °C, whereas at 28 °C, PUFA increased to proportions exceeding those observed at 9 °C. Lipid peroxidation could be observed under all experimental conditions. Both enzymatic and non-enzymatic antioxidant defense systems acted cooperatively to cope with oxidative stress leading to lipid peroxidation, which was not affected by temperature acclimation as indicated by malondialdehyde concentration, in spite of a higher polyinsaturation in cold-acclimated fish which would be predicted to increase their vulnerability to peroxidation. However, in warm-acclimated, Ni-exposed fish, in which the highest proportion of PUFA was observed, lower concentrations of malondialdehyde were measured, suggesting an overcompensation of antioxidant mechanisms in these fish which could represent a substantial metabolic cost and explain their lower condition.
Biomonitoring is an important tool for the assessment of the quality and functions of ecosystems, providing information about the pollutants present and the direct effects that they exert on organisms. Biomonitoring relies upon the quantification of variables that can be biochemical, genetic, morphological and physiological changes. Such variables are designated as biomarkers, and multiple biomarkers are usually determined simultaneously in order to have a more integrated analysis and information about sublethal early effects of contaminants. In this work, we quantified biomarkers, associated with oxidative stress (glutathione-S-transferases GSTs, and catalase CAT, activities; levels of peroxidative alterations, by the thiobarbituric acid reactive substances assay, TBARS) and neurotoxicity (acetylcholinesterase activity, AChE) in the polychaete Hediste diversicolor. Organisms were collected at three distinct estuaries, Ria de Aveiro (Laranjo and São Jacinto), Douro River (São Paio, Afurada, and Ribeira da Granja), both impacted by human activities, and Minho River (Seixas), which has been used as a reference site. Obtained data showed the occurrence of anti-oxidant responses, in most samples from contaminated sites, which was not followed however by the occurrence of oxidative damage in organisms from Ria de Aveiro. None of the analyzed organisms had significant impairment of cholinesterasic activity, suggesting the absence of a prior exposure to neurotoxic compounds. In fact, organisms collected at Ria de Aveiro had largely increased AChE activity, suggesting an uncommon paradoxical biological response that is further discussed.
Penconazole (PEN) is a fungicide used in agriculture that has been classified as hazardous to human and the environment. The objective of this work was to identify PEN urinary metabolites in humans and propose a biomarker for PEN exposure. Five urine samples were collected form agricultural workers who worked with and were exposed to PEN. Samples were analyzed by liquid chromatography coupled with hybrid triple quadrupole-linear ion trap mass spectrometry, with the source operating in the electrospray ionization mode. Metabolites previously identified in animal studies were searched as possible metabolites in humans. Candidate metabolites were first identified by multiple reaction monitoring following the protonated molecular ions that generated the protonated triazole moiety, which is expected to be present in all PEN metabolites; second, the isotopic patterns of the molecular ions were checked for consistency with the presence of two chlorine atoms; third, the full mass spectra were evaluated for consistency with the molecular structure. Seven different oxidized metabolites were found, both in the free and glucuronide conjugate forms. The major metabolite was the monohydroxyl-derivative PEN-OH (median molar fraction approximately 0.92 as a sum of free and glucuronide conjugated form). The product of further oxidation was the carboxyl-derivate PEN-COOH (median molar fraction approximately 0.03). After hydrolysis with β-glucuronidase, the free compounds were quantified in the presence of deuterated PEN as an internal standard; PEN-OH levels ranged from 230 to 460 µg/L, and PEN-COOH levels ranged from 5.2 to 16.7 µg/L. We propose pathway for PEN metabolism in humans and suggest PEN-OH, after hydrolysis of glucuronide conjugates, as a biomarker for monitoring human exposure to PEN.
This review presents and evaluates evidence relevant to the mechanisms of metal carcinogenicity with special emphasis on the emerging hypothesis of the oxidative nature of metals' effect on DNA. The carcinogenic transition metals are capable of in vivo binding with the cell nucleus and causing promutagenic damage that includes DNA base modifications, inter- and intramolecular crosslinking of DNA and proteins, DNA strand breaks, rearrangements, and depurination. The chemistry of that damage and the resulting mutations observed in vitro and in metal-induced tumors are both characteristic for oxidative attack on DNA. The underlying mechanism involves various kinds of active oxygen and other radical species arising from metal-catalyzed redox reactions of O2, H2O2, lipid peroxides, and others, with certain amino acids, peptides, and proteins. Other metal-mediated pathogenic effects, such as enhancement of lipid peroxidation, stimulation of inflammation, inhibition of cellular antioxidant defenses, and inhibition of DNA repair, may also contribute to that mechanism. Thus far, published data revealing the oxidative character of metal-induced promutagenic DNA alterations are particularly strong for two of the most powerful human metal carcinogens, chromium and nickel. However, without excluding contribution of other effects, the promotion of oxidative damage tends to take the leading role in explaining mechanisms of carcinogenicity and acute toxicity of certain other metals as well.
Background
Advanced oxidation protein products (AOPPs) are acknowledged as a novel marker of oxidation-mediated protein damage. This study aimed to investigate the plasma levels of AOPPs in postmenopausal osteoporotic women, and to determine the relationship between AOPPs accumulation and lumbar bone mineral destiny (BMD) or bone turnover markers.
Material/Methods
Lumbar BMD was measured by dual-energy X-ray absorptiometry. Plasma AOPPs levels as a marker of protein oxidation damage and malondialdehyde (MDA) levels as a marker of lipid peroxidation were measured by spectrophotometry. The concentrations of 2 specific markers of bone turnover, bone-specific alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase5b, (TRACP 5b) were quantified using ELISA kits.
Results
We recruited 60 postmenopausal women meeting osteoporosis (OP) diagnostic criteria of World Health Organization (WHO) and 60 postmenopausal women without OP. Plasma levels of AOPPs (P<0.001), BALP (P<0.001) and TRACP 5b (P<0.001) were statistically significantly increased in the postmenopausal osteoporotic women compared with controls, but there was no statistically significant difference in MDA (P=0.124) between the 2 groups. Plasma AOPPs levels were negatively correlated with lumbar BMD and positively correlated with bone turnover markers both in postmenopausal osteoporotic women and in all subjects. However, plasma MDA levels were not correlated with lumbar BMD or bone turnover markers.
Conclusions
In postmenopausal osteoporotic women elevated AOPPs is associated with reduced BMD and increased bone turnover markers. Because AOPPs is stable and easy to detect it may be used as a simple plasma marker to predict the severity of postmenopausal OP.
Chlorpyrifos is a widely used organophosphorous pesticide in agriculture and environmental health. Laboratory studies of chlorpyrifos have revealed acute lethal toxicity at very low concentration (96-h LC50) of 0.39μgL(-1) to the freshwater snail, Lanistes carinatus. Acetylcholinesterase (AChE) inhibition progressed and reached 52% and 78% of the control after 28-d exposure to 0.09 and 0.29μgL(-1) chlorpyrifos, respectively. Catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities increased in comparison to control group in the first period of exposure (7-21d), then decreased relative to the control in the second period of exposure (21-28d). A significant (p<0.05) glutathione (GSH) depletion was observed in snails exposed to 0.09 and 0.29μgL(-1) in comparison to the control, whereas malondialdehyde (MDA) content gradually increased in a dose-dependent manner. This study showed that alterations in antioxidant enzyme activities along with depletion of GSH content and elevation of MDA content can be used as biomarkers in environmental assessment programs.
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The growing demand of human populations for food supplies has led to an increase in the use of synthetic products, mainly pesticides, which induce adverse effects not only to target organisms, but also to non-target biota of agroecosystems. Aquatic ecosystems in the proximity of agricultural areas are particularly vulnerable to pesticides, which cause underperformance or extinction of non-target sensitive species. Once in the aquatic system, these chemicals can affect biological processes at multiple levels (molecular, individual, populational), causing ecosystem imbalance across multiple scales. In this study, the effect of a commercial formulation of a herbicide (Primextra® Gold TZ) and its main active ingredient (a.i., S-metolachlor) was studied on a freshwater cladoceran species (Daphnia longispina), at different levels of biological organization and temporal scales. S-metolachlor is used in many herbicide formulations applied in corn/maize cultures, which is a relevant culture worldwide. As a first step, the acute and chronic effects of both commercial formulation and a.i. were quantified, and both formulations negatively affected the cladoceran's survival and reproductive parameters (age at first reproduction, number of offspring and number of broods), as well as the population's rate of increase. Whilst acute effects were comparable, the commercial formulation was slightly more toxic (EC50 was two-times lower) than the a.i. in chronic exposures, being prejudicial to D. longispina populations above 4.0 mg/L of S-metolachlor. In a second experimental step, we focused on the potential multi-generational impacts of the exposure to the a.i. alone on biochemical (lipid biomarkers, namely fatty acids) and populational responses, because of the relevance of S-metolachlor as a biosynthesis inhibitor in many herbicidal formulations. The herbicide caused a significant decrease in Daphnia fecundity (in the size of the 1st clutch), but no concomitant alterations were found in fatty acid profiles of mothers or offspring. More important, this experiment showed that S-metolachlor did not cause effects in the subsequent generation, thus suggesting that biotic communities may recover after exposure to the xenobiotic.