Novel bioassay based on acetylcholinesterase and lactate dehydrogenase activities to evaluate the toxicity of chemicals to soil isopods

This study developed a bioassay with the isopod Porcellio dilatatus based on the activity of the enzymes acetylcholinesterase (AChE) and lactate dehydrogenase (LDH). The in vivo effects of the insecticides parathion-ethyl and endosulfan-sulfate on AChE and LDH activities of P. dilatatus under laboratory conditions were investigated. The route of uptake of the pesticides was through the food (alder leaves). Isopods were exposed to a wide range of concentrations of parathion or endosulfan (0.1, 1, 10, 25, 50, 100, 250, and 500 microg/g of food) for 21 days. After this period, the activity of AChE and LDH was determined. Parathion induced significant depression of both AChE and LDH activities. Animals fed with endosulfan-contaminated food exhibited lower LDH activities than control animals, while AChE activity was similar in all treatments. The results of the present investigation suggest that the isopod. P. dilatatus is a suitable species for use in toxicity tests and indicate that the enzymes AChE and LDH could be used as effect criteria both in laboratory and in field studies with this species.     

Chronic effect of endosulfan on the testicular functions of rat

Aim: To find out the toxic effect of endosulfan on the tesficular function of pubertal rats, Methods: Male rats of pu-bertal age were orally administered endosulfan at a dose of 1.0 mg/kg body weight for 30 days. Twenty-four hours af-ter the last tmagnent, the rats were sacrificed and the testis, epididymis, seminal vesicles and ventral prostate were re-moved and weighed. A 10 % testicular homogenate was prepared for biochemical estimations. Results: In endosul-fan-treated rats, there were a reduction in the body weight and the weights of testis and accessory sex organs, a de-crease in the testicular lactate and pyruvate activities, and in the testicular DNA and RNA concentrations, whereas thetesticular protein concentration was slightly increased; the specific activity of testicular steroidogenic enzyme, 33OH-steroid dehydrogenase and the ascorbic acid level were decreased, which were correlated with a decrease in steroidoge-nesis. The lysosomal enzyme acid phosphatase and brush-border enzyme alkaline phosphatase activities were also de-creased in the testis of treated rats. Conclusion: In puhertal rats, endosulfan treaanent inhibits the testicular functions.(Asian J Androl 1999 Dec; 1 : 203 - 206)     

Genetic and biochemical biomarkers in the macrophyte Bidens laevis L. Exposed to a commercial formulation of endosulfan

Previous studies in the wetland macrophyte Bidens laevis L have demonstrated that the insecticide endosulfan induces a high frequency of somatic chromosome aberrations in anaphase–telophase (CAAT) but no DNA changes as determined by the single cell gel electrophoresis (Comet) assay. Thus, cytogenetic biomarkers appear to be more sensitive to the toxic effects of the insecticide than the DNA molecule in the studied species. For this reason, the goals of this study were to use cytogenetic biomarkers—CAAT and abnormal metaphase—and defense biomarkers such as the activity of the antioxidant enzymes—guaiacol peroxidases (POD), glutathione reductase, and microsomal and cytosolic (m‐ and c‐) glutathione‐S‐transferase (GST)—to evaluate in B. laevis effects caused by a commercial formulation of endosulfan. The frequency of CAAT was increased at 5, 10, 50, and 100 μg/L endosulfan with respect to the negative controls by 3.1, 2.5, 2.5, and 3.2‐fold, respectively while the frequency of abnormal metaphases was also increased at the same concentrations by 3.5, 2.8, 3.2, and 11.3‐fold, respectively. In addition to these aneugenic effects, other abnormalities such as C‐mitosis and chromosome clumping were observed at 10 μg/L endosulfan. On the other hand, POD induction at 0.02, 0.5, 5, and 10 μg/L and m‐GST inhibition at 0.5, 10, and 50 μg/L in plants exposed during 24 h to endosulfan were observed but all of these responses were highly variable. In conclusion, only cytogenetic biomarkers like CAAT in B. laevis can serve potentially as early warning systems to detect environmentally relevant concentrations of endosulfan in aquatic ecosystems. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1063–1071, 2014.     

Toxicity of endosulfan: Distribution of α- and ß-isomers of racemic endosulfan following oral administration in rats

Endosulfan was administered orally (2.5 and 7.5 mg/kg) daily to male rats for a period of 60 days. The distribution pattern of α and ß-isomers was studied using a gas-liquid chromatography equipped with an electron capture detector. There was a significant increase in liver and lung weights. The testes weight was slightly decreased. No significant change in weights of other tissues was observed. At both dose levels, the concentration of α-isomer was highest in kidney (574 and 1655 ng/g, respectively), followed by lung, ventral prostate, spleen, testes and brain. In the seminal vesicle, epididymis, heart and liver, the concentration of ß-isomer was higher than the α-isomer. The results of the study indicated a differential ability to accumulate the two isomers of endosulfan which may help to explain the difference in the toxic potential of the α- and ß-isomers.     

Analysis of endosulfan and its metabolites in rat plasma and selected tissue samples by gas chromatography-mass spectrometry

A method has been developed for the determination of trace levels of alpha-endosulfan, beta-endosulfan, endosulfan sulfate, and endosulfan diol in rat plasma and tissue samples. Endosulfan and its metabolites in the plasma samples were extracted with solid-phase extraction Chromabond-end-capped C18 cartridges and analyzed by a Shimadzu QP-5050A gas chromatograph-mass spectrometer (GCMS) with quadrupole detector in selected-ion-monitoring mode. The analysis of endosulfan and its metabolites in liver and kidney samples involved solvent extraction, Florisil solid-phase-extraction cleanup, and quantitation by GCMS. Recovery experiments for the plasma and tissue samples were conducted over concentration ranges of 10-100 ng mL(-1) and 100-1000 ng mL(-1), respectively. The method was applied to the analysis of trace levels of endosulfan and its metabolites in plasma and tissue samples collected from an animal study. Trace levels of alpha-endosulfan and beta-endosulfan in the ranges of undetectable to 3.11 microg g(-1) and undetectable to 1.19 microg g(-1), respectively, were detected in the kidney samples, whereas trace levels of endosulfan sulfate in the range of 0.02-0.22 microg g(-1) were detected in the liver samples of rats. Neither endosulfan nor its metabolites was detected in any of the plasma samples.     

硫丹对成年大鼠生精功能的影响和氧化损伤

目的　研究硫丹对大鼠生精功能的影响是否与氧化损伤有关。方法　成年雄性SPFWistar大鼠随机分为 6组 ,每组 6只。 1～ 4组ig硫丹 0 ,2 .5 ,5 .0 ,7.5mg·kg- 1,每天 1次 ,每周 6次 ,持续 10周。5～ 6组在给硫丹 7.5mg·kg- 1的同时 ,ip维生素C(VitC) 2 0 ,4 0mg·kg- 1。给药结束时检查各组动物的每日精子生成量 (DSP)、附睾精子数和形态 ,并检测血清和睾丸、肝组织中的过氧化脂质 (LPO)和 8 羟基脱氧鸟苷 (8 OHdG)的含量。结果　给硫丹的5 .0和 7.5mg·kg- 1组出现短暂的中枢神经系统中毒症状。给药结束时 3个单给硫丹组DSP和附睾精子计数都低于对照组 ,精子畸形率则高于对照组。同时ipVitC两组的DSP和精子计数虽然仍低于对照组 ,但都比单给硫丹组有所改善。给硫丹组血清、肝脏和睾丸组织中的LPO和 8 OHdG都高于对照组。同时注射VitC组血清和上述组织中的LPO和8 OHdG都比单给硫丹 7.5mg·kg- 1组低。结论　大鼠长期大剂量接触硫丹能引起精子生成减少 ,异常精子比例增多 ,并能引起肝脏和睾丸组织脂质过氧化和DNA氧化损伤 ,而这些改变都能被抗氧化剂VitC部分改善 ,提示氧化损伤可能是硫丹生殖毒性的作用机理之一。     

Citrinin and endosulfan induced maternal toxicity in pregnant Wistar rats: pathomorphological study

Dietary exposures to environmental food pollutants such as mycotoxin(s) or pesticide(s) have gained immense significance due to their adverse effects on production and reproduction in animal and human populations. The present investigation was conducted to evaluate the maternal toxicity of citrinin (CIT) and endosulfan administered per os either alone or in combination in pregnant rats during gestational days 6-20. CIT (group I, 10 mg kg(-1) feed, through diet) and endosulfan (group II, 1 mg kg(-1) body weight, by oral intubation) when administered either alone or in combination (group III) in Wistar rats caused clinical signs of toxicity and pathomorphological changes in all the toxin treated groups, the severity being more pronounced in the combination treatment compared with that observed in the control (group IV). The rate of fetal resorptions was highest (22.22%) in the combination treatment followed by endosulfan (16.48%) and CIT (12.50%) treatment groups compared with the control group (3.86%). The histopathological changes such as engorged vasculature, vacuolar degeneration and karyomegaly in liver; congestion, tubular degeneration and cast formation in kidneys; vascular changes and hemosiderosis in uterus and lymphocytic depletion and apoptosis in the lymphoid organs were recorded in the animals of the toxin treated groups. The lesions were consistent and more severe in the combination treatment group compared with the individual treatment groups, suggesting an additive interaction of CIT and endosulfan in inducing maternal toxicity in Wistar rats.     

硫丹的毒理学研究进展

硫丹被列入<斯德哥尔摩公约>禁用物质列表,将在世界范围内逐步被淘汰,本文总结硫丹的毒理学研究概况,以利大家认识其危害,了解其被禁用的原因.     

Evaluation of cytotoxicity and genotoxicity of pesticide mixtures on lymphocytes

The cytotoxicity and genotoxicity of pesticide mixtures viz. endosulfan?+?chlorpyrifos, chlorpyrifos?+?profenofos, and endosulfan?+?profenofos were evaluated on cultured human peripheral blood lymphocytes using assays for cell viability, and genotoxicity using chromosomal aberrations test and comet assay. The LC₅₀ values for cytotoxicity were 3.50?μM, 4.18?μM, and 10.5?μM for profenofos, endosulfan, and chlorpyrifos respectively. When combined in equimolar concentrations, the LC₅₀ values for cytotoxicity were 1.4?μM, 1.8?μM, and 2.0?μM for endosulfan?+?chlorpyrifos, chlorpyrifos?+?profenofos, and endosulfan?+?profenofos, respectively. Higher concentrations of individual pesticides (0.5–4.0?μM) but very low concentrations of pesticide mixtures caused significant DNA damage. Additive index values indicated a synergistic effect of toxicity for endosulfan?+?chlorpyrifos combination (1.12 TTU). The binary mixture of chlorpyrifos?+?profenofos showed an additive toxicity (0.46 TTU) while an antagonistic effect was observed for endosulfan?+?profenofos combination. Synergism could be due to these complementary pesticides simultaneously acting in different ways, magnifying their efficacy, whereas an additive interaction would imply that the chemicals are acting by the same mechanism and at the same target. Analysis of toxicity of pesticide mixtures may serve as important biomarker for occupational and household exposure to pesticides, with different modes of action.