Effects of the insecticides malathion and diazinon on the early oogenesis in mice in vitro

Lower malathion concentrations reduce testosterone biosynthesis by Leydig TM3 cells in vitro by altering cellular redox profile and inducing oxidative damage

Malathion is an organophosphate pesticide used in agriculture and control of the Aedes aegypti mosquito. As previous reports have indicated the potential of malathion to compromise testosterone production in in vivo models, the objective of this study was to elucidate the mechanisms underlying the impairment of Leydig cell function, considering its critical role in male reproductive function. To this end, murine Leydig TM3 cells were exposed to concentrations of 1, 10, 100 or 1000 μM malathion for 24 h for evaluation of the compound on cell viability. Subsequently, concentrations of 1, 10, and 100 μM malathion were employed for a 24-h period to assess testosterone biosynthesis, levels of cytokines IL-1β, IL-6, IL-10, and TNF-α, as well as the redox profile. Malathion exerted a concentration-dependent impact on cell viability. Notably, the lower concentrations of malathion (1 and 10 μM) were found to impair testosterone biosynthesis in TM3 cells. While there were changes in IL-1 and TNF-α levels at specific concentrations, no direct correlation with altered hormone production was established. Our investigation revealed that varied malathion concentrations induced oxidative stress by increase in superoxide anion and a compensatory rise in antioxidants. In conclusion, the observed changes in the oxidative profile of TM3 cells were linked to functional impairment, evidenced by reduced testosterone biosynthesis at lower malathion concentrations.

Fertility loss: negative effects of environmental toxicants on oogenesis

There has been a global decline in fertility rates, with ovulatory disorders emerging as the leading cause, contributing to a global lifetime infertility prevalence of 17.5%. Formation of the primordial follicle pool during early and further development of oocytes after puberty is crucial in determining female fertility and reproductive quality. However, the increasing exposure to environmental toxins (through occupational exposure and ubiquitous chemicals) in daily life is a growing concern; these toxins have been identified as significant risk factors for oogenesis in women. In light of this concern, this review aims to enhance our understanding of female reproductive system diseases and their implications. Specifically, we summarized and categorized the environmental toxins that can affect oogenesis. Here, we provide an overview of oogenesis, highlighting specific stages that may be susceptible to the influence of environmental toxins. Furthermore, we discuss the genetic and molecular mechanisms by which various environmental toxins, including metals, cigarette smoke, and agricultural and industrial toxins, affect female oogenesis. Raising awareness about the potential risks associated with toxin exposure is crucial. However, further research is needed to fully comprehend the mechanisms underlying these effects, including the identification of biomarkers to assess exposure levels and predict reproductive outcomes. By providing a comprehensive overview, this review aims to contribute to a better understanding of the impact of environmental toxins on female oogenesis and guide future research in this field.

Associations of single and multiple organophosphate pesticide exposure with female infertility in the USA: data from the 2015-2018 National Health and Nutrition Examination Survey

Substantial evidence has shown that organophosphate pesticide (OPP) exposure altered the reproductive system functions, such as prolonged menstrual cycles, sexual hormone imbalance, and changes in ovarian weight. However, the association of OPP exposure with female infertility is unclear. We explored the relationships of four single OPP metabolites and their mixed exposure with self-reported infertility among women aged 20-50 in the USA using the data from two cycles (2015-2016 and 2017-2018) of the National Health and Nutrition Examination Survey (NHANES) by multiple logistic regression, Bayesian kernel machine regression (BKMR), and quantile g-computation (QGC). Eventually, 659 females were included in our study. Among these females, 77 participants were ever infertile. Multiple logistic regression showed that the odds ratios (ORs) in the second and third tertiles of dimethylphosphate (DMP) for female infertility were 2.53 (95% confidence interval (95%CI): 1.20-5.32, P value = 0.016) and 2.96 (95%CI: 1.18-7.47, P value = 0.023) compared to the lowest tertile after adjusting for all covariates (P for trend = 0.022). A significantly positive association between the mixed OPP metabolites and infertility was observed in the BKMR model, in which DMP had the highest posterior inclusion probability (PIP = 0.741). The QGC model showed similar results, in which OPP metabolite mixtures increased the risk of female infertility, with DMP as a significantly positive contributor to the outcome. This study revealed the potential harm of OPP mixtures for female infertility in the USA, and DMP played the most critical role in female infertility risk among all OPP metabolites.

Glyphosate effects on the female reproductive systems: a systematic review

Glyphosate-based herbicides (GBHs) are organophosphate pesticides, which interrupt the chemicals involved in the endocrine system and cause lifelong disorders in women's reproductive system. The current study was designed to systematically evaluate the association between GBH exposure and the female reproductive tract. According to PRISMA Guidelines, the systematic review was performed, searching online databases, including Google Scholar, Web of Science, PubMed, and Scopus, throughout April 2020. Studies with Rodent, lamb, and fish or exposed to GBH to affect the female reproductive system were selected. All studies were in the English language. Two investigators independently assessed the articles. The first author's name, publication date, animal model, age, sample size, gender, dose, duration, and route of exposure and outcomes were extracted from each publication. The present review summarizes 14 publications on uterus alterations and oocytes, histological changes ovary, and assessed mRNA expression, protein expression, serum levels progesterone, and estrogen and intracellular Reaction Oxygen Species (ROS) in rodents, fish, and lamb exposed to GHB exposure. Most of the studies reported histological changes in ovarian and uterus tissue, alterations in serum levels, and increased oxidative stress level following exposure to GBH. Additionally, due to alterations in the reproductive systems (e.g., histomorphological changes, reduction of the mature follicles, higher atretic follicles, and interstitial fibrosis), it seems the GBH-induced female these alterations are both dose- and time-dependent. The present findings support an association between GBH exposure and female reproductive system diseases. However, more studies are needed to identify the mechanisms disrupting the effects of GBH and their underlying mechanisms. Considering the current literature, it is recommended that further investigations be focused on the possible effects of various pesticides on the human reproductive system.

Effects of Some Insecticides (Deltamethrin and Malathion) and Lemongrass Oil on Fruit Fly (Drosophila melanogaster)

<b>Background and Objective:</b> The continuous use of pesticides in the ecosystem is of great concern, as some of them are highly stable and impact non-target organisms. The effect was tested of different concentrations of insecticides such as (Deltamethrin and Malathion) and natural products, Including, lemongrass oil on Fruit Fly (<i>Drosophila melanogaster</i>), to calculate the concentration at which the highest mortality occurred and death half the number of individuals after 96 hrs, as well as calculating the half-lethal time for individuals. <b>Materials and Methods:</b> This study, which evaluated the toxicity of five different concentrations (0.75, 1.00, 1.25, 1.50 and 1.75 mg L<sup>1</sup>) of Malathion, (0.05, 0.10, 0.21, 0.53 and 1.48 mg L<sup>1</sup>) of Deltamethrin and lemongrass oil (0.25, 0.50, 0.75, 1.00 and 1.50 mg L<sup>1</sup>) on the insect of <i>Drosophila melanogaster</i> after 96 hrs of treatment. <b>Results:</b> From the results of this study, the concentration (LC<sub>50 </sub>= 2.938 mg L<sup>1</sup>) of Malathion leads to kills half of the individuals, compared to Deltamethrin a higher concentration (LC<sub>50 </sub>= 4.8673 mg L<sup>1</sup>) that leads to killing half of the individuals. While lemongrass oil the concentration (LC<sub>50 </sub>= 9.7478 mg L<sup>1</sup>) leads to kills half of individuals. Also, when used Deltamethrin it takes (LT<sub>50 </sub>= 660.277) hours to kill half of the individuals compared to Malathion, which takes approximately (LT<sub>50</sub> = 321.862) hours to death half of the individuals. But lemongrass oil (LT<sub>50 </sub>= 819.745) hours to kill half of the individuals. <b>Conclusion:</b> In conclusion, the lemon plant and its components have excellent potential for being used in the control of <i>Drosophila melanogaster</i>, which had an effective role in biological control.

Mechanisms of deleterious effects of some pesticide exposure on pigs

The increase in the size of the global population increases the food and energy demand, making the use of pesticides in agricultural and livestock industries unavoidable. Exposure to pesticides can be toxic to the non-target species, such as humans, wildlife, and livestock, in addition to the target organisms. Various chemicals are used in the livestock industry to control harmful organisms, such as insects, weeds, and parasites. Pigs are one of the most important food sources for humans. In addition, pigs can be used as promising models for assessing the risk of absorption of environmental pollutants through the skin and oral exposure since they are physiologically similar to humans. Exposure to numerous environmental pollutants, such as mycotoxins, persistent organic pollutants, and heavy metals, has been reported to adversely affect growth, fertility, and endocrine homeostasis in pigs. Various pesticides have been observed in porcine tissues, blood, urine, and processed foods; however, there is a lack of comprehensive understanding of their effects on porcine health. This review provides a comprehensive description of the characteristics of pesticides that pigs can be exposed to and how their exposure affects porcine reproductive function, intestinal health, and endocrine homeostasis in vivo and in vitro.

Organophosphate toxicity: updates of malathion potential toxic effects in mammals and potential treatments

Organophosphorus insecticides toxicity is still considered a major global health problem. Malathion is one of the most commonly used organophosphates nowadays, as being considered to possess relatively low toxicity compared with other organophosphates. However, widespread use may lead to excessive exposure from multiple sources. Mechanisms of MAL toxicity include inhibition of acetylcholinesterase enzyme, change of oxidants/antioxidants balance, DNA damage, and facilitation of apoptotic cell damage. Exposure to malathion has been associated with different toxicities that nearly affect every single organ in our bodies, with CNS toxicity being the most well documented. Malathion toxic effects on liver, kidney, testis, ovaries, lung, pancreas, and blood were also reported. Moreover, malathion was considered as a genotoxic and carcinogenic chemical compound. Evidence exists for adverse effects associated with prenatal and postnatal exposure in both animals and humans. This review summarizes the toxic data available about malathion in mammals and discusses new potential therapeutic modalities, with the aim to highlight the importance of increasing awareness about its potential risk and reevaluation of the allowed daily exposure level.

Exposure to Organophosphate Pesticides and Menstrual Cycle Characteristics in Chinese Preconceptional Women

Organophosphates (OPs) are the most heavily used pesticides in China. The Chinese population, including preconceptional women, is highly exposed, yet little is known regarding the associations between OP exposure and menstruation in humans. We conducted a cross-sectional analysis in women preparing for pregnancy to investigate the relationship between biomarkers of OP exposure and menstrual cycle characteristics. From 2013 to 2015, 627 women visiting free preconception-care clinics at 2 maternity hospitals in Shanghai, China, were included. Information on menstrual cycle characteristics was obtained through questionnaires. OP exposure was assessed by measuring urine concentrations of 6 dialkylphosphate metabolites (dimethylphosphate, dimethylthiophosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate, and diethyldithiophosphate). The relationship between concentrations of dialkylphosphate metabolites and menstrual cycle characteristics was analyzed using multiple linear regression models and logistic regression models. Log-transformed levels of diethyl phosphate metabolites (the sum of diethylphosphate and diethylthiophosphate levels) were related to a higher risk of irregularity of menstrual cycles (adjusted odds ratio = 2.36, 95% confidence interval: 1.28, 4.34). Subjects with a higher concentration of diethyl phosphate metabolites (log-transformed) had a shorter duration of menstrual bleeding (adjusted β = -0.33, 95% confidence interval: -0.64, -0.02). The findings suggest that OP exposure may be associated with alterations in menstrual function in preconceptional women.

Melatonin protects against defects induced by malathion during porcine oocyte maturation

Malathion (MAL) is a common organophosphorus pesticide and affects both animal and human reproduction. However, the mechanisms regarding how MAL affects the mammalian oocyte quality and how to prevent it have not been fully investigated. In this study, we used porcine oocyte as a model and proved that MAL impaired porcine oocyte quality in a dose-dependent manner during maturation. MAL decreased the first polar body extrusion, disrupted spindle assembly and chromosome alignment, impaired cortical granules (CGs) distribution, and increased reactive oxygen species (ROS) level in oocytes. RNA-seq analysis showed that MAL exposure altered the expression of 2,917 genes in the porcine maturated oocytes and most genes were related to ROS, the lipid droplet process, and the energy supplement. Nevertheless, these defects could be remarkably ameliorated by adding melatonin (MLT) into the oocyte maturation medium. MLT increased oocyte maturation rate and decreased the abnormities of spindle assembly, CGs distribution and ROS accumulation in MAL-exposed porcine oocytes. More important, MLT upregulated the expression of genes related to lipid droplet metabolism (PPARγ and PLIN2), decreased lipid droplet size and lipid peroxidation in MAL-exposed porcine oocytes. Finally, we found that MLT increased the blastocysts formation and the cell numbers of blastocysts in MAL-exposed porcine oocytes after parthenogenetic activation, which was mediated by reduction of ROS levels and maintaining lipid droplet metabolism. Taken together, our results revealed that MLT had a protective action against MAL-induced deterioration of porcine oocyte quality.

Evaluation of oxidative stress indices after exposure to malathion and protective effects of ascorbic acid in ovarian tissue of adult female rats

Background

Malathion is one of organophosphate pesticides that is extensively used in farming and crops to control pests. Malathion induces oxidative stress in the various tissues such as the reproductive system.

Objective

To determine the effects of malathion on malondialdehyde (MDA) level and glutathione (GSH) content in female rat ovary tissue as well as to assess the protective role of Ascorbic Acid.

Methods

This study was carried out at the Department of Anatomy and Cell Biology (School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran) in 2015. In this experimental study, 30 adult, female, Wistar rats (weight range: 200-250 g) were divided into five groups, each group consisting of six rats: control group (no interventions), sham group (normal saline 0.9% 50 mg/kg), experimental group 1 (Ascorbic Acid 200 mg/kg), experimental group 2 (malathion 50 mg/kg), and experimental group 3 (malathion 50 mg/kg + Ascorbic Acid 200 mg/kg). Malathion, solvents and Ascorbic Acid were injected intraperitoneally. After two weeks, the animals were anaesthetized with intraperitoneal ketamine/xylazine (60 and 6 mg/kg, respectively) and then scarified, and the right ovarian was used to measure levels of MDA, a marker of lipid peroxidation, and GSH content. Data were analyzed by SPSS version 16, using descriptive statistics, One Way ANOVA, and Tukey-Kramer test. A p-value <0.05 was set as significance level.

Results

This study has shown that malathion increased MDA level and reduced GSH content compared with the control group (p<0.001). Also, administration of malathion in combination with Ascorbic Acid, reduced MDA level and increased the GSH content in rat ovarian tissue.

Conclusion

Malathion induced lipid peroxidation and Oxidative stress in the ovarian of Rats. In addition, it appears that Ascorbic Acid, due to its antioxidant, can recover malathion-induced poisonous changes.

Malathion-induced spermatozoal oxidative damage and alterations in sperm quality of endangered trout Salmo coruhensis

The use of pesticides has been increased along with increasing the farming activities and has caused environmental impacts deleteriously. In particular, non-target organisms including fish can be affected by toxic effects of pesticides. Therefore, the impacts of malathion (MTN) on oxidative stress and sperm quality were investigated in vitro. The MTN concentrations used on this study were 0 (control), 75, 100, and 125 μg/L. Lipid peroxidation (MDA), non-enzymatic (GSH), and enzymatic (SOD, GSH-Px, and CAT) activities in spermatozoa were examined for determination of oxidative stress status. Our findings showed that motility rate and period of sperm cells significantly decreased with exposure to MTN. Biochemical assays revealed that CAT activity and levels of MDA, GSH increased in spermatozoa based on concentration while activity of GSH-Px and SOD decreased. Consequently, spermatozoa were highly sensitive to MTN exposure. MTN has disruptive effects on sperm quality and caused to oxidative stress in spermatozoa.

Oxidative stress as a damage mechanism in porcine cumulus-oocyte complexes exposed to malathion during in vitro maturation

Malathion is one of the most commonly used insecticides. Recent findings have demonstrated that it induces oxidative stress in somatic cells, but there are not enough studies that have demonstrated this effect in germ cells. Malathion impairs porcine oocyte viability and maturation, but studies have not shown how oxidative stress damages maturation and which biochemical mechanisms are affected in this process in cumulus-oocyte complexes (COCs). The aims of the present study were to determine the amount of oxidative stress produced by malathion in porcine COCs matured in vitro, to define how biochemical mechanisms affect this process, and determine whether trolox can attenuate oxidative damage. Sublethal concentrations 0, 750, and 1000 µM were used to evaluate antioxidant enzyme expressions, reactive oxygen species (ROS production), protein oxidation, and lipid peroxidation, among other oxidation products. COCs viability and oocyte maturation decreased in a concentration-dependent manner. Malathion increased Cu, Zn superoxide dismutase (SOD1), glutathione-S-transferase (GST), and glucose 6 phosphate dehydrogenase (G6PD) protein level and decreased glutathione peroxidase (GSH-Px) and catalase (CAT) protein level. Species reactives of oxygen (ROS), protein oxidation and Thiobarbituric acid reactive substances (TBARS) levels increased in COCs exposed to the insecticide, but when COCs were pre-treated with the trolox (50 µM) 30 min before and during malathion exposure, these parameters decreased down to control levels. This study showed that malathion has a detrimental effect on COCs during in vitro maturation, inducing oxidative stress, while trolox attenuated malathion toxicity by decreasing oxidative damage.

Profenofos, an Acetylcholinesterase-Inhibiting Organophosphorus Pesticide: A Short Review of Its Usage, Toxicity, and Biodegradation

Pesticides play an important role in the protection of different crops. Among the diverse sets of pesticides used all over the world, the organophosphates are the most widely used group. Profenofos [O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate] is one of the most largely used organophosphate insecticides on field crops, vegetables, and fruit crops. The World Health Organization classifies this compound as moderately hazardous (Toxicity Class II), and its residues have been found in vegetables like okra [ (L.) Moench], gooseberries ( sp.), green chilies [ (L.)], curry leaves [ (L.) Spreng], mint leaves [ (L.)], and coriander leaves [ (L.)]. Dietary intake of profenofos (PFF) is the major exposure pathway for humans. When applied to agricultural fields, PFF residues spread into every part of the environment: ambient air, surface water, and soil. In this review, we discuss the worldwide usage of PFF pesticide, its toxic effects on humans and other living organisms in the environment, and biodegradation of this chemical by various microbial strains. To date, no complete biodegradation pathway has been established for PFF pesticide, calling for a study of this nature.

Evaluating the protective effects of vitamin C on serum and erythrocyte cholinesterase activity of male rats exposed to malathion

Introduction

Malathion is one of organophosphate poisons (OPPs) that inhibit cholinesterase activity and induce oxidative stress in target organs, such as the reproductive system. The aim of this study was to assess the effects of Malathion on serum and erythrocyte cholinesterase activity in male rats and also to assess the protective effects of vitamin C in this regard.

Methods

This experimental study was performed in the Pharmacology Laboratory of the Pharmacy Faculty and in the Advanced Histology Techniques Laboratory of the Medical Faculty of Mashhad University of Medical Sciences (MUMS) in January 2014. Thirty male wistar rats, weighting 200–250 g, were divided into five groups of six. The different groups were exposed as follows: group 1: Malathion 50 mg/kg; group 2: Vitamin C; group 3: Malathion plus Vitamin C with the specified doses; sham group: normal saline; and control group: no exposure. After six weeks, 3 ml blood samples were taken from the rats, and titrimetric and Ellman methods were used to assess serum and erythrocyte cholinesterase activity, respectively. The data was analyzed by SPSS 16, and p < 0.05 was considered significant.

Results

The activities of serum and erythrocyte cholinesterase were inhibited significantly in the Malathion exposed group compared to the control group (p < 0.001). The administration of Vitamin C alone significantly increased the activities of serum and erythrocyte cholinesterase. The serum and erythrocyte cholinesterase inhibition showed improvement in the group that received both Malathion and Vitamin C.

Conclusion

Malathion reduced the activities of serum and erythrocyte cholinesterase in exposed animals. It probably has the same intoxication effects on people who are exposed. Improvement of cholinesterase activity by antioxidant effects of Vitamin C suggests that Vitamin C supplementation can be used to decrease side effects of OPP exposure.

Transmission electron microscopic analysis of malathion-induced cytotoxicity in granulosa cells of caprine antral follicles

Malathion, one of the most abundantly used organophosphate pesticides, has immoderate potency as a cytotoxic and genotoxic compound that induces toxicity in granulosa cells, resulting in its apoptosis. Thus, the present study aims to employ ultrastructural analysis for assessing the cytotoxicity of malathion at nanomolar concentrations (1 nM and 10 nM) in granulosa cells of caprine antral follicles at different exposure durations. Transmission electron microscopy revealed diminished cell-cell contact and cellular integrity, presence of crescent-shaped nucleus, chromatin condensation, and pyknosis with nuclear membrane folding, accumulation of lipid droplets with occurrence of cytoplasmic protrusions in granulosa cells treated with 1 nM malathion, whereas at 10 nM concentration, along with apoptotic attributes, prominent association of nucleus, endoplasmic reticulum, mitochondria and lipid droplets, nucleus invagination into lipid droplets, apical localization of lipid bodies, and occurrence of autophagic body were observed as compared to healthy granulosa cells in control with normal intact cellular integrity, well-developed cellular association, and doubled membrane nuclear lamina with homogenously dispersed chromatin surrounded by intact mitochondria with well-developed cristae. Thus, the results of ultrastructural analysis clearly suggest that nanomolar concentration of malathion induces apoptotic hallmarks within the granulosa cells of antral follicles that play a consequential role in increasing the incidence of follicular atresia, thereby affecting the overall fertility.

Effect of phosalone on testicular tissue and in vitro fertilizing potential

BACKGROUND

The current study aimed to evaluate the effects of phosalone (PLN) as an organophosphate (OP) compound on testicular tissue, hormonal alterations and embryo development in rats.

MATERIALS AND METHODS

In this experimental study, we divided 18 mature Wistar rats into three groups-control, control-sham and test (n=6 per group). Animals in the test group received one-fourth the lethal dose (LD50) of PLN (150 mg/kg), orally, once per day for 45 days. DNA laddering and epi-fluorescent analyses were performed to evaluate testicular DNA fragmentation and RNA damage, respectively. Serum levels of testosterone and inhibin-B (IN-B) were evaluated. Testicular levels of total antioxidant capacity (TAC), total thiol molecules (TTM) and glutathione peroxidase (GSH-px) were analyzed. Finally, we estimated sperm parameters and effect of PLN on embryo development. Two-way ANOVA was used for statistical analyses.

RESULTS

There was severe DNA fragmentation and RNA damage in testicular tissue of animals that received PLN. PLN remarkably (p<0.05) decreased testicular TAC, TTM and GSH-px levels. Animals that received PLN exhibited significantly (p<0.05) decreased serum levels of testosterone and IN-B. Reduced sperm count, viability, motility, chromatin condensation and elevated sperm DNA damage were observed in the test group rats. PLN resulted in significant (p<0.05) reduction of in vitro fertilizing (IVF) potential and elevated embryonic degeneration.

CONCLUSION

PLN reduced fertilization potential and embryo development were attributed to a cascade of impacts on the testicles and sperm. PLN promoted its impact by elevating DNA and RNA damages via down-regulation of testicular endocrine activity and antioxidant status.

Malathion-induced granulosa cell apoptosis in caprine antral follicles: an ultrastructural and flow cytometric analysis

Organophosphate pesticides (OPs) like malathion interfere with normal ovarian function resulting in an increased incidence of atresia and granulosa cell apoptosis that plays a consequential role in the loss of ovarian follicles or follicular atresia. The aim of present study was to assess malathion-induced (100 nM) reproductive stress, ultrastructural damage and changes in apoptosis frequency in ovarian granulosa cells of antral follicles. Transmission electron microscopy (TEM) was employed for ultrastructural characterization, oxidative stress was evaluated using thiobarbituric acid reactive substances (TBARS) assay to measure lipid peroxidation, and apoptosis was quantified via flow cytometry. By TEM, apoptosis was identified by the presence of an indented nuclear membrane with blebbing, pyknotic crescent-shaped fragmented nuclei, increased vacuolization, degenerating mitochondria, and lipid droplets. The results indicate a significant increase in malondialdehyde (MDA) level (nmols/g wet tissue) at a 100 nM dose of malathion i.e. 7.57±0.033*, 8.53±0.12*, and 12.87±0.78** at 4, 6, or 8 h, respectively, as compared with controls (6.07±0.033, p<0.01*, p<0.05**) showing a positive correlation between malathion-induced lipid peroxidation and percentage of granulosa cell apoptosis (r=1; p<0.01). The parallel use of these three methods enabled us to determine the role of malathion in inducing apoptosis as a consequence of cytogenetic damage and oxidative stress generated in granulosa cells of antral follicles.

Prenatal stress and development: beyond the single cause and effect paradigm

Our awareness of the causes of stress-induced developmental dysfunction has increased dramatically over the past decade, and it is becoming increasingly clear that a number of factors can have considerable impacts on the developing fetus. Although there is a tendency in investigations of developmental teratogens to attribute specific causes to adverse fetal outcomes, it is important we recognize that for most developmental dysfunctions it is unlikely a single cause, but yet a series of environmental insults combined with genetic predisposition that ultimately leads to a disease state. Nonetheless, a number of developmental teratogens, such as maternal psychological stress and chemical exposures, have been shown to increase the likelihood of developmental defects. These defects can manifest during development, leading to observable birth defects, or could become evident long after birth, even into adulthood. In addition, epigenetic mutations in the germline can alter the phenotype of successive generations through transgenerational inheritance, and in this way environmental factors can alter the developmental outcomes and disease predispositions of future generations. Understanding this complexity is essential to interpretations of causality in the studies of stress-induced developmental dysfunction and needs to be fully considered to more effectively interpret potential outcomes.

Gene expression analysis in gonads and brain of catfish Clarias batrachus after the exposure of malathion

Pesticides like malathion have the potential to disrupt development and reproduction of aquatic organisms including fishes. To investigate the likely consequences of malathion exposure at low doses in juvenile catfish, Clarias batrachus, we studied the expression pattern of genes encoding certain transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes which are known to be involved in gonadal development along with histological changes. To compare further, we also analyzed certain brain specific genes related to gonadal axis. Fifty days post hatch catfish fingerlings were exposed continuously to 1 and 10 µg/L of malathion for 21 days. Results from these experiments indicated that transcript levels of various genes were altered by the treatments, which may further affect the gonadal development either directly or indirectly through brain. Histological analysis revealed slow progression of spermatogenesis in testis, while in ovary, the oil droplet oocytes were found to be higher after treatment (10 µg/L). Our findings revealed that the exposure of malathion, even at low doses, hinder or modulate early gonadal development differentially by targeting gene expression pattern of transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes with an evidence on histological changes. Further, some of the genes showed differential expression at the level of brain in male and female sex after the exposure of malathion.

Gas chromatography-mass spectrometry for metabolite profiling of Japanese medaka (Oryzias latipes) juveniles exposed to malathion

PURPOSE

We evaluate malathion toxicity to Japanese medaka (Oryzias latipes) juveniles by using a mass spectrometry combined with gas chromatography (GC/MS) metabolomics approach.

METHODS

Medaka were exposed to low (L) and high (H) concentrations (nominally 20 and 2,000 μg/L, respectively) of water-borne malathion. Metabolites were extracted from the fish, derivatized, and analyzed by GC/MS. Identified metabolites were subjected to one-way analysis of variance and principal component analysis (PCA). We examined the variations in the amounts of the metabolites during the exposure period.

RESULTS AND DISCUSSION

At 24 h, control, L, and H groups were separated along PC1, suggesting that the effects of malathion depended on exposure concentration. The PCA results at 96 h suggest that the metabolite profiles variations of the L and H groups differed, and thus that the effects of malathion in groups differed. At 24 h, the amounts of amino acids in both exposed groups were lower than the control group amounts, perhaps owing to accelerated protein synthesis. At 96 h, the amounts of almost all the amino acids increased in the L group but decreased in the H group relative to the control group amounts, suggesting the proteolysis occurred in the L group while protein synthesis continued in the H group, that the high malathion exposure affected the fish. In addition, at 96 h, gluconeogenesis may have been induced in the L group but not in H group.

CONCLUSIONS

Malathion exposure may have altered the balance between protein synthesis and degradation and induced gluconeogenesis in medaka. Our results suggest that metabolomics will be useful for comprehensive evaluation of toxicity.

Multi residue analysis of pesticides in wheat and khat collected from different regions of Ethiopia

The present study investigated the presence and level of pesticide residues in wheat and khat samples collected from various localities of Ethiopia. The khat samples from Galemso and Aseno had p,p'-DDT concentrations ranged from 141.2 to 973.0 μg/Kg and 194.3-999.0 μg/Kg, respectively. Diazinon was detected in all the khat samples from BadaBuna (173.9-686.9 μg/Kg) but not in any of the samples from Galemso and Aseno. Diazinon was detected in all the wheat samples obtained from both Arsi and Bale (125.8 and 125.6 μg/Kg, respectively) and aldrin levels in these samples were below the quantification limit. Khat may be a contributing factor in the pathological diseases found among khat users.

Interaction of malathion, an organophosphorus pesticide with Rhizopus oryzae biomass

Adsorption of malathion on Rhizopus oryzae biomass (ROB) with special reference to binding mechanism has been described. ROB has been found to adsorb approximately 85% of malathion from its aqueous solution as against 47-68% by other fungal biomasses. Hydrogen ion concentration does not influence the adsorption of malathion by ROB which follows Langmuir-Freundlich dual equilibrium isotherm model (r(2)=0.998). Both physical and chemical interactions are responsible for binding of malathion on ROB. Scanning electron micrographs and EDXA spectra exhibit adsorption of the pesticide on cell surface of ROB. Studies with cell surface polysaccharides show that chitosan through its amine groups contributes largely in the adsorption of malathion. Extraction of lipids from ROB decreases its adsorption capacity to the extent of 36.37-94.02%, depending on the polarity of the solvent.