Article

Histopathology of Male Swiss Albino Mice reproductive system due to Toxic effects of Thiamethoxam

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Abstract

Abstract The present study aimed to investigate the effect of thiamethoxam on the physiological and histological status of male mice reproductive system. This study was carried out at College of Veterinary Medicine-Baghdad, from August to December 2016. Fifty adult males Swiss albino mice, aged two months, were divided into five equal groups. First group immunized with B. abortus antigen. Second group was dosed orally thiamethoxam. Third group were subjected to same treatments in the 1st and 2nd group. The 4th group injected virulent B. abortus. The 5th group acted as negative controls. All animals were euthanized and blood samples were taken for hormonal analysis and pieces of testes, epididymis were fixed in 10% normal buffer formalin for routine histopathological examination. Results showed that thiamethoxam significantly decreased the sperm viability, motility and testosterone level. In conclusion, thiamethoxam possess toxic effect for spermatogenesis in mice. To avoid its harm on human, the use of thiamethoxam should be expertised.

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The cytochrome P450 (CYP)-mediated biotransformation of the organophosphorothioate insecticides chlorpyrifos and diazinon was investigated. Rates of desulphuration to the active oxon metabolite (chlorpyrifos-oxon and diazinon-oxon) and dearylation to non-toxic hydrolysis products were determined in human liver microsome preparations from five individual donors and in recombinant CYP enzymes. Chlorpyrifos and diazinon underwent desulphuration in human liver microsome with mean Km = 30 and 45 microM and V(max) = 353 and 766 pmol min(-1) mg(-1), respectively. Dearylation of these compounds by human liver microsome proceeded with Km = 12 and 28 microM and V(max) = 653 and 1186 pmol min(-1) mg(-1), respectively. The apparent intrinsic clearance (V(max)/Km) of dearylation was 4.5- and 2.5-fold greater than desulphuration for chlorpyrifos and diazinon, respectively. Recombinant human CYP2B6 possessed the highest desulphuration activity for chlorpyrifos, whereas CYP2C19 had the highest dearylation activity. In contrast, both desulphuration and dearylation of diazinon were catalysed at similar rates, in the rank order CYP2C19 > CYP1A2 > CYP2B6 > CYP3A4. Both organophosphorothioates were more readily detoxified (dearylation) than bioactivated (desulphuration) in all human liver microsome preparations. However, the role of individual CYP enzymes in these two biotransformation pathways varied according to the structure of the organophosphorothioate, which was reflected in different activation/detoxification ratios for chlorpyrifos and diazinon. Variability in activity of individual CYP enzymes may influence interindividual sensitivity to the toxic effects of chlorpyrifos and diazinon.
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Agricultural chemicals frequently alter human health or development, typically because they have endocrine agonist or antagonist activities and alter hormone-regulation of gene expression. The insecticide, diazinon, was evaluated for gene expression disrupting activity using MCF-7 cells, an estrogen-dependent human cell line, to examine the capacity of the insecticide to disrupt gene expression essential for morphological development, immune system development or function, and/or central nervous system development and function. MCF-7 cells were treated with 30, 50 or 67 ppm diazinon, and gene expression was measured in treated cells compared to expression in untreated or estrogen-treated cells. DNA microarray analysis of diazinon-treated cells showed significant up- or down-regulation of a large number of genes compared to untreated cells. Of the 600 human genes on the Phase 1 chip utilized for these studies, two specific genes--calreticulin and TGF-beta3--were selected for corroboration using quantitative real time PCR (qrtPCR). qrtPCR, completed to assess gene expression levels for calreticulin and TGFbeta3, confirmed results showing significant up-regulation of these two genes obtained from the microarray data. These studies were designed to provide baseline data on the gene expression-altering capacity of a specific chemical, diazinon, and allow a partial assessment of the potentially deleterious effects associated with exposure of human cells to this chemical. Currently, it is not known whether results from cells in vitro can be extrapolated to human health consequences of chemical exposure.
Article
Several studies have shown a decline in human semen quality and increased risks of male subfertility. This paper provides an overview of the mechanisms of pesticide-induced reproductive toxicity and the effects on male fertility since exposure to pesticides may be one of the causes of these disorders. Pesticides may directly damage spermatozoa, alter Sertoli cell or Leydig cell function, or disrupt the endocrine function in any stage of hormonal regulation (hormone synthesis, release, storage, transport, and clearance; receptor recognition and binding; thyroid function; and the central nervous system). These mechanisms are described with respect to the effects of pesticide exposure in vitro and in vivo. In epidemiologic studies, effects on sperm quality and time to pregnancy are reviewed. Clear effects on male fertility have been demonstrated for some pesticides [eg, dibromochloropropane, ethylene dibromide]. But results from more recent studies are inconsistent, and no uniform conclusion can be drawn about the effects of pesticides on male reproduction.
Article
Due to the key role of the human chorionic gonadotropin hormone (hCG) in placental development, the aim of this study was to characterize the human trophoblastic luteinizing hormone/chorionic gonadotropin receptor (LH/CG-R) and to investigate its expression using the in vitro model of human cytotrophoblast differentiation into syncytiotrophoblast. We confirmed by in situ immunochemistry and in cultured cells, that LH/CG-R is expressed in both villous cytotrophoblasts and syncytiotrophoblasts. However, LH/CG-R expression decreased during trophoblast fusion and differentiation, while the expression of hCG and hPL (specific markers of syncytiotrophoblast formation) increased. A decrease in LH/CG-R mRNA during trophoblast differentiation was observed by means of semi-quantitative RT-PCR with two sets of primers. A corresponding decrease ( approximately 60%) in LH/CG-R protein content was shown by Western-blot and immunoprecipitation experiments. The amount of the mature form of LH/CG-R, detected as a 90-kDa band specifically binding (125)I-hCG, was lower in syncytiotrophoblasts than in cytotrophoblasts. This was confirmed by Scatchard analysis of binding data on cultured cells. Maximum binding at the cell surface decreased from 3,511 to about 929 molecules/seeded cells with a kDa of 0.4-0.5 nM. Moreover, on stimulation by recombinant hCG, the syncytiotrophoblast produced less cyclic AMP than cytotrophoblasts, indicating that LH/CG-R expression is regulated during human villous trophoblast differentiation.
Article
Several studies have suggested that human semen quality has declined over the past decades and some of them have associated it with occupational exposure to pesticides. However, most of these studies have not been associated with a reliable exposure level and have been designed mostly as cross-sectional studies. The present work evaluates, in a longitudinal follow-up study, the effect of organophosphate pesticides (OP) at three occupational exposure levels on semen quality. In addition, the study examined the association between OP urinary levels and sperm parameters in exposed and unexposed workers. A total of 139 semen samples from 52 volunteers were assessed. Urinary OP levels were measured by gas-liquid chromatography. The results revealed that the poorest semen quality was found among the subjects with the highest OP exposure and the highest urinary OP levels. Seasonal variations in sperm concentration and sperm count were registered. The results showed a significant decrease in total sperm count among subjects with the highest exposure to OP. Further studies assessing the effects of OP on male reproductive health should be controlled by the variability in human sperm parameters, sperm seasonality, spermatogenesis time and the changing OP exposure level in men highly exposed to OP.
Article
Imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine, CAS 138261-41-3] belongs to a relatively new class of insecticidal chemistry, the chloronicotinyl neonicotinoid compounds. Animal studies indicate relatively low toxicity to mammals. Despite wide usage in some countries, the understanding of human poisoning is quite limited. Here we report a fatal case of rapid ingestion of an insecticide formulation containing imidacloprid. Clinical manifestation included severe vomiting, hypertension, tachycardia, mydriasis with sluggish reaction to light, and loss of consciousness. In the course of toxicity, the patient manifested bradycardia, bradypnea, and cardiopulmonary arrest and death. Because moderate- to high-dose imidacloprid in animals causes central nervous system activation similar to nicotine, including tremors, impaired papillary function, and hypothermia, it is more likely that the formulation ingredients caused most of the clinical symptoms including central nervous system depression and gastrointestinal irritation.
antioxidant enzymes in erythrocytes in vitro
antioxidant enzymes in erythrocytes in vitro. Human and Experimental Toxicology Journal. 2004; 23:9-13.
Clinical Veternary Microbilogy. Wlfe publishing mosby–year Book
  • Pj Quin
  • Me Carter
  • Bk Narkey
  • Gr Carter
Quin PJ, Carter ME, Narkey BK, Carter GR. Clinical Veternary Microbilogy. Wlfe publishing mosby–year Book. Inc. Europe limited. 6 th edition. 2004, 250.
Toxicity Evaluation Consultants
  • M B Mcgregor
  • Roland S Thiamethoxa
McGregor MB, Roland S. Thiamethoxa. Toxicity Evaluation Consultants, Aberdour, Scotland Federal Institute for Risk Assessment, Berlin, Germany. 2010; 611-623.
  • P Maienfisch
  • M Angst
  • F Brandl
  • W Fischer
  • D Hofer
  • H Kayser
Maienfisch P, Angst M, Brandl F, Fischer W, Hofer D, Kayser H et al. Chemistry and Biology of Thiamethoxam: a Second Generation Neonicotinoid. Pest Management Science, 2001; 57(10):906-913.
In vitro effect of malathion and diazinon on oocyte fertilization and embryo development in porcine
  • Y Ducolomb
  • E Casas
  • A Valdez
  • G Gonzales
  • M Altamirano -Lozano
  • M Betancourt
Ducolomb Y, Casas E, Valdez A, Gonzales G, Altamirano -Lozano M, Betancourt M. In vitro effect of malathion and diazinon on oocyte fertilization and embryo development in porcine. Cell Biology and Toxicology. 2009; 25:623-633.
Clinical Veternary Microbilogy. Wlfe publishing mosby-year Book
  • P J Quin
  • M E Carter
  • B K Narkey
  • G R Carter
Quin PJ, Carter ME, Narkey BK, Carter GR. Clinical Veternary Microbilogy. Wlfe publishing mosby-year Book. Inc. Europe limited. 6 th edition. 2004, 250.
Chemicals for Molecular Targets and Adverse Outcomes
Chemicals for Molecular Targets and Adverse Outcomes. Environmental Health Perspectives, 2016; 124(7):1050-1061.