The Effects of the Endocrine Disruptors Dithiocarbamates on the Mammalian Ovary with Particular Regard to Mancozeb

Ultrastructural Evaluation of Mouse Oocytes Exposed In Vitro to Different Concentrations of the Fungicide Mancozeb

Mancozeb is a widely used fungicide, considered to be an endocrine disruptor. In vivo and in vitro studies evidenced its reproductive toxicity on mouse oocytes by altering spindle morphology, impairing oocyte maturation, fertilization, and embryo implantation. Mancozeb also induces dose-dependent toxicity on the ultrastructure of mouse granulosa cells, including chromatin condensation, membrane blebbing, and vacuolization. We evaluated the effects on the ultrastructure of mouse oocytes isolated from cumulus-oocyte complexes (COCs), exposed in vitro to increasing concentrations of mancozeb. COCs were matured in vitro with or without (control) low fungicide concentrations (0.001-1 μg/mL). All mature oocytes were collected and prepared for light and transmission electron microscopy. Results showed a preserved ultrastructure at the lowest doses (0.001-0.01 μg/mL), with evident clusters of round-to-ovoid mitochondria, visible electron-dense round cortical granules, and thin microvilli. Mancozeb concentration of 1 μg/mL affected organelle density concerning controls, with a reduction of mitochondria, appearing moderately vacuolated, cortical granules, and microvilli, short and less abundant. In summary, ultrastructural data revealed changes mainly at the highest concentration of mancozeb on mouse oocytes. This could be responsible for the previously described impaired capability in oocyte maturation, fertilization, and embryo implantation, demonstrating its impact on the reproductive health and fertility.

Childhood exposure to non-persistent pesticides and pubertal development in Spanish girls and boys: Evidence from the INMA (Environment and Childhood) cohort

This study assessed cross-sectional associations between urinary metabolites of non-persistent pesticides and pubertal development in boys and girls from urban and rural areas in Spain and examined effect modification by body mass index (BMI). Four metabolites of insecticides (TCPy, metabolite of chlorpyrifos; IMPy, metabolite of diazinon; DETP, non-specific metabolite of organophosphates; 3-PBA, metabolite of pyrethroids) and the metabolite of ethylene-bis-dithiocarbamate fungicides (ETU) were quantified in urine collected in 2010-2016 from 7 to 11-year-old children (606 girls, 933 boys) participating in the INMA Project. Pubertal development was ascertained by Tanner stages and/or parent-reported Pubertal Development Scale (PDS). Associations between pesticide metabolites and odds of being in stage 2+ for breast development (girls), genital development (boys), pubic hair growth (girls and boys), and/or overall puberty onset, gonadarche, and adrenarche (PDS for girls and boys) were examined by mixed-effect logistic regression. Effect modification by BMI was explored by interaction terms and stratified analysis. In girls, DETP and ETU concentrations>75th percentile (P75) were associated with higher odds of overall puberty development (OR [95%CI] = 1.86 [1.07-3.24] and 1.71 [1.03-2.83], respectively, for > P75 vs. undetected concentrations), while ETU > P75 was also associated with higher odds of breast development (OR [95%CI] = 5.55 [2.83-12.91]), particularly in girls with underweight/normal weight (OR [95%CI] = 10.08 [2.62-38.76]). In boys, detection of TCPy (40%) and 3-PBA (34%) was associated with higher odds of genital development (OR [95%CI] = 1.97 [1.08-3.57] and 2.08 [1.15-3.81], respectively), and the association with 3-PBA was observed in boys with overweight/obesity alone. In addition, ETU > P75 was associated with higher odds of genital development in boys with underweight/normal weight (OR [95%CI] = 2.89 [1.08-7.74]) but higher DETP with lower odds of puberty in boys with overweight/obesity (OR [95%CI] = 0.94 [0.89-0.99] per log-unit increase in concentration). Results suggest an association of childhood exposure to ETU and certain insecticides with earlier puberty in girls and boys that may be modified by child BMI.

Characterization of physiological and antioxidant responses in Run1Ren1 Vitis vinifera plants during Erysiphe necator attack

Grapevine is a fruit crop of major significance worldwide. Fungal attacks are one of the most relevant factors affecting grapevine yield and fruit quality, and powdery mildew caused by Erysiphe necator is one of the most harmful fungal diseases for this fruit-bearing species. Incorporating resistance genes such as Run1 and Ren1 in new vine selections offers a sustainable alternative to control the disease. These combined loci produce an immune response that prevents the development of the disease. However, to date studies are lacking concerning whether this response generates alterations in the physiological and antioxidant parameters of resistant plants in the presence of the fungus or if it has an associated energy cost. Therefore, the main goal of our research was to determine if Run1Ren1 plants present alterations in their physiological and biochemical parameters in the presence of the fungus. To achieve this target, a previously characterized resistant Run1Ren1 genotype and the susceptible Carménère cultivar were analyzed. We evaluated photochemical parameters (Fv'/Fm', ΦPSII and ETR), net photosynthesis (Pn), photosynthetic pigments, transpiration (E), stomatal conductance (g_s ), oxidative stress parameters (MDA), antioxidant activity, and phenols. Our results show that the physiological parameters of Run1Ren1 plants were not negatively affected by the fungus at 10 days post-inoculation, contrasting with alterations observed in the susceptible plants. Therefore, we propose that the resistance response triggered by Run1Ren1 is physiologically and biochemically advantageous to grapevines by preventing the development of powdery mildew infection.

Assessment of Mancozeb Exposure, Absorbed Dose, and Oxidative Damage in Greenhouse Farmers

Mancozeb (MNZ) is a fungicide commonly employed in many countries worldwide. This study assesses MNZ absorption dynamics in 19 greenhouse farmers, specifically following dermal exposure, aiming to verify the efficacy of both preventive actions and protective equipment. For data collection, a multi-assessment approach was used, which included a survey to record study population features. MNZ exposure was assessed through the indirect measurement of ethylene thiourea (ETU), widely employed as an MNZ biomarker. The ETU concentration was measured with the patch method, detecting environmental ETU trapped in filter paper pads, applied both on skin and working clothes, during the 8 h work shift. Urine and serum end-of-shift samples were also collected to measure ETU concentrations and well-known oxidative stress biomarkers, respectively, namely reactive oxygen metabolites (ROMs), advanced oxidation protein products (AOPPs), and biological antioxidant potential (BAP). It was observed that levels of ETU absorbed and ETU excreted were positively correlated. Additionally, working clothes effectively protected workers from MNZ exposure. Moreover, following stratification of the samples based on the specific working duty (i.e., preparation and spreading of MNZ and manipulation of MNZ-treated seedlings), it was found that the spreading group had higher ETU-related risk, despite lower chronic exposure levels. AOPP and ROM serum levels were higher in MNZ-exposed subjects compared with non-exposed controls, whereas BAP levels were significantly lower. Such results support an increase in the oxidative stress upon 8 h MNZ exposure at work. In particular, AOPP levels demonstrated a potential predictive role, as suggested by the contingency analysis results. Overall, this study, although conducted in a small group, confirms that ETU detection in pads, as well as in urine, might enable assessment of the risk associated with MNZ exposure in greenhouse workers. Additionally, the measurement of circulating oxidative stress biomarkers might help to stratify exposed workers based on their sensitivity to MNZ. Pivotally, the combination of both ETU measurement and biological monitoring might represent a novel valuable combined approach for risk assessment in farmhouse workers exposed to pesticides. In the future, these observations will help to implement effective preventive strategies in the workplace for workers at higher risk, including greenhouse farmers who are exposed to pesticides daily, as well as to clarify the occupational exposure levels to ETU.

Histopathological, immunohistochemical and biochemical alterations in liver tissue after fungicide-mancozeb exposures in Wistar albino rats

PURPOSE

To evaluate the histopathological, immunohistochemical, and biochemical effects of liver changes after mancozeb administration.

METHODS

Rats were divided into groups-the control group (n=7) and the mancozeb group (n=7)-, given 500 mg/kg mancozeb dissolved in corn oil daily for four weeks by an orogastric tube. Caspase-3 and tumor necrosis factor-alpha (TNF-α) primary antibodies were used for immunohistochemical analysis.

RESULTS

Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values of the mancozeb group increased significantly than ones of the control group. Venous dilatation, inflammation, hepatocyte degeneration, TNF-α, and caspase-3 expression scores increased significantly in the mancozeb group. In the mancozeb group, intensive caspase-3 expression was observed in hepatocyte cells around the central vein in the center of the liver lobule, and there was an increase in TNF-α expression in the inflammatory cells around the enlarged central vein and Kupffer cells and apoptotic hepatocyte cells.

CONCLUSIONS

Subacute mancozeb exposure in rats leads to elevated toxicity with impaired liver function, increased inflammation in tissue and increased apoptosis due to cellular damage in the liver, and decreased liver regeneration ability due to congestion and degeneration of blood vessels.

Low level of mancozeb exposure affects ovary in mice

Mancozeb (MCZ) is widely used as a protective fungicide. This study aimed to explore the effects of low level MCZ exposure on ovary in mice. Twenty Kunming mice were randomly divided into control and MCZ groups (10 mice each). The mice in the MCZ group were given 100 mg/kg MCZ daily via gavage. The mice were sacrificed to collect serum and ovaries on day 31. The experimental indicators were then assessed. The weight of MCZ-exposed mice significantly reduced while ovarian index significantly increased compared with the control group. The FSH, LH, E2, P, CAT, SOD and MDA contents in the serum were significantly decreased and the content of estradiol significantly increased after MCZ exposure. Histological observation showed that the ovarian structure of mice exposed to MCZ was damaged, and the apoptosis was increased. Immunohistochemistry and RT-qPCR showed that the expression of Bax, caspase-3 and caspase-9 significantly increased in the MCZ- group. Conversely, Bcl-2 expression significantly decreased. Transcriptome sequencing showed that the expression of NADH dehydrogenase ND3, ND4L, ND6 subunits, Cyt b, and SDHC genes in mitochondria were down-regulated after MCZ exposure, similar to real-time PCR analysis. These results collectively indicate that the MCZ can affect the abnormal function of mitochondrial respiratory chain, lead to oxidative phosphorylation decoupling, produce oxidative stress, and finally cause ovarian injury and apoptosis in mice.

Powdery Mildew Resistance Genes in Vines: An Opportunity to Achieve a More Sustainable Viticulture

Grapevine (Vitis vinifera) is one of the main fruit crops worldwide. In 2020, the total surface area planted with vines was estimated at 7.3 million hectares. Diverse pathogens affect grapevine yield, fruit, and wine quality of which powdery mildew is the most important disease prior to harvest. Its causal agent is the biotrophic fungus Erysiphe necator, which generates a decrease in cluster weight, delays fruit ripening, and reduces photosynthetic and transpiration rates. In addition, powdery mildew induces metabolic reprogramming in its host, affecting primary metabolism. Most commercial grapevine cultivars are highly susceptible to powdery mildew; consequently, large quantities of fungicide are applied during the productive season. However, pesticides are associated with health problems, negative environmental impacts, and high costs for farmers. In paralleled, consumers are demanding more sustainable practices during food production. Therefore, new grapevine cultivars with genetic resistance to powdery mildew are needed for sustainable viticulture, while maintaining yield, fruit, and wine quality. Two main gene families confer resistance to powdery mildew in the Vitaceae, Run (Resistance to Uncinula necator) and Ren (Resistance to Erysiphe necator). This article reviews the powdery mildew resistance genes and loci and their use in grapevine breeding programs.

Reproductive toxicity by exposure to low concentrations of pesticides in Caenorhabditis elegans

In view of the recurrent applications of pesticides in agricultural producing countries, the increased presence of these substances in the environment raise a demand for the evaluation of adverse effects on non-target organisms. This study assesses the impact of exposure to five pesticides suspected of being endocrine disruptors (atrazine, 2,4-dichlorophenoxyacetic acid, mancozeb, chlorpyrifos and cypermethrin) on the reproductive development of the nematode Caenorhabditis elegans. To this end, nematodes in the L4 larval stage were exposed to different concentrations of pesticides for 24 h and the consequences on brood size, percentage of gravid nematodes, expression of reproductive-related genes and vitellogenin trafficking and endocytosis were measured. Moreover, 17β-estradiol was used as an estrogenic control for endocrine disrupting compounds throughout the work. The results showed that all the pesticides disturbed to some extent one or more of the evaluated endpoints. Remarkably, we found that atrazine, 2,4-dichlorophenoxyacetic acid and chlorpyrifos produced comparable responses to 17β-estradiol suggesting that these pesticides may have estrogen-like endocrine disrupting activity. Atrazine and 17β-estradiol, as well as 2,4-dichlorophenoxyacetic acid and chlorpyrifos to a lesser extent, decreased the brood size, affected vitellogenin trafficking and endocytosis, and changed the expression of several reproductive-related genes. Conversely, mancozeb and cypermethrin had the least impact on the evaluated endpoint. Cypermethrin affected the brood size at the highest concentration tested and mancozeb altered the distribution of vitellogenin only in approximately 10% of the population. However, both products overexpressed hus-1 and vit-2 genes, indicating that an induction of stress could interfere with the normal development of the nematode. In conclusion, our work proved that C. elegans is a useful biological model to identify the effects of estrogen-like endocrine disruptor compounds, and the sublethal endpoints proposed may serve as an important contribution on evaluating environmental pollutants.

Urinary metabolites of non-persistent pesticides and serum hormones in Spanish adolescent males

OBJECTIVE

To assess the relationship of urinary concentrations of ethylenethiourea (ETU), the main degradation product of ethylene bis-dithiocarbamate fungicides, 3-phenoxybenzoic acid (3-PBA), a common metabolite of many pyrethroids, and 1-naphthol (1N), a metabolite of the carbamate insecticide carbaryl, with hormone concentrations in adolescent males; and to examine interactions between pesticide metabolites and polymorphisms in xenobiotic metabolizing enzymes, including CYP2C19 and CYP2D6, in relation to hormone concentrations.

METHODS

A cross-sectional study was conducted in 134 males from the Spanish Environment and Childhood (INMA)-Granada cohort. Urine and serum samples were collected from participants during the same clinical visit at the age of 15-17 years. First morning urine void was analyzed for concentrations of ETU, 3-PBA, and 1N. Serum was analyzed for concentrations of reproductive hormones (testosterone, 17β-estradiol [E₂], dehydroepiandrosterone sulfate [DHEAS], sex hormone binding globulin [SHBG], luteinizing hormone [LH], follicle stimulating hormone [FSH], anti-Müllerian hormone [AMH], and prolactin), thyroid hormones (free thyroxine [FT4], total triiodothyronine [TT3], and thyroid stimulating hormone [TSH]), insulin growth factor 1 (IGF-1), adrenocorticotropic hormone (ACTH), and cortisol. CYP2C19 G681A and CYP2D6 G1846A polymorphisms were determined in blood from 117 participants. Multiple linear regression, interaction terms, and stratified analyses were performed.

RESULTS

Urinary ETU was detected in 74.6% of participants, 1N in 38.1%, and 3-PBA in 19.4%. Positive associations between detectable 3-PBA and TT3 and between detectable 1N and DHEAS were found, and marginally-significant associations of 1N with reduced E₂ and FSH were observed. Poor CYP2C19 and CYP2D6 metabolizers (GA and AA genotype carriers) showed a greater increase in DHEAS for detected versus undetected 1N compared with GG genotype carriers. Poor CYP2D6 metabolizers (1846 GA and AA genotypes) evidenced increased cortisol for detected versus undetected ETU.

CONCLUSIONS

The associations observed between urinary pesticide metabolites and altered thyroid and reproductive hormones are novel and should be verified in studies with larger sample size. Further research on gene-environment interactions is warranted to establish individual susceptibility to pesticides and the risk of adverse health effects.

Occupational exposure of rural workers to pesticides in a vegetable-producing region in Brazil

The health of family farmers is at risk due to occupational exposure to pesticides. The aims of the current study were to investigate the level of farmers' perception of risks associated with pesticide use and to assess their health condition based on biochemical and immunological tests. Family farmers living in a vegetable-producing region in Southern Brazil were selected to participate in the study. More than 70% of the family farmers were often exposed to more than one type of pesticides; 41.2% were intensively using several pesticides for more than one decade and 74.4% were not using personal protective equipment (PPE) at the time of pesticide handling due to low perception of the risks posed by these chemicals. Enzymatic analysis performed in participants' blood samples showed changes in catalase (CAT) and glutathione reductase (GR) activity, in lipid peroxidation (TBARS) and carbonylated protein levels, as well as in chemoattractant (IL-8) and anti-inflammatory (IL-10) interleukin expression. Low perception of health-related risks posed by pesticides can be attributed to factors such as low schooling and lack of information, which put farmers' health at risk, as evidenced by blood biochemical and immunological changes.

Female Fertility and Environmental Pollution

A realistic picture of our world shows that it is heavily polluted everywhere. Coastal regions and oceans are polluted by farm fertilizer, manure runoff, sewage and industrial discharges, and large isles of waste plastic are floating around, impacting sea life. Terrestrial ecosystems are contaminated by heavy metals and organic chemicals that can be taken up by and accumulate in crop plants, and water tables are heavily contaminated by untreated industrial discharges. As deadly particulates can drift far, poor air quality has become a significant global problem and one that is not exclusive to major industrialized cities. The consequences are a dramatic impairment of our ecosystem and biodiversity and increases in degenerative or man-made diseases. In this respect, it has been demonstrated that environmental pollution impairs fertility in all mammalian species. The worst consequences are observed for females since the number of germ cells present in the ovary is fixed during fetal life, and the cells are not renewable. This means that any pollutant affecting hormonal homeostasis and/or the reproductive apparatus inevitably harms reproductive performance. This decline will have important social and economic consequences that can no longer be overlooked.

Determination of Mancozeb, a Pesticide Used Worldwide in Agriculture: Comparison among GC, LC, and CE

Background:

The determination of mancozeb, a fungicide extensively used in agriculture, is a challenge, due to the nature of the compound, a manganese and zinc complex of ethylenebis dithiocarbamate and because of the general instability of the dithiocarbamates.

Methods:

Mancozeb was analyzed in a GC-EI-MS system after derivatization by CE-UV with detection at 280 nm and in LC-ESI-MS-MS in MRM mode.

Results:

A comparative study of the performance of three different techniques for the detection of mancozeb was explored, highlighting the advantages and drawbacks of them. The limits of detection and quantification of the techniques were determined; the repeatability was assessed, showing values of relative standard deviation. Gas chromatography, although very sensitive, was not reproducible enough due to fast degradation of the derivatization product, whereas capillary electrophoresis-UV showed problems in run-to-run reproducibility which had the worst limit of detection. LC coupled with tandem mass spectrometry was the most reliable and precise technique and was able to determine the main degradation product of Mancozeb, at the same time. The proposed LC procedure was verified by applying it to a commercial formulation, a fungicide of known concentration, and to Italian white grapes treated with the formulation sprayed during cultivation.

Conclusion:

Thanks to the simplified sample handling, the proposed method resulted to be simple, fast, green, economic, and suitable for residue analysis in grapes and other fruits. Finally, the method was compared with other similar investigations.

The impact of endocrine disruptor chemicals on oocyte/embryo and clinical outcomes in IVF

The negative impact of endocrine-disrupting pesticides on human fertility is now a key issue in reproductive health. There are much fewer literature data about the impact of pesticide exposure on women than on men and very few studies of women participating in an in vitro fertilization (IVF) programme. In the present review, we found that (1) various pesticides with an endocrine-disrupting action are associated with poor oocyte maturation and competency, embryonic defects and poor IVF outcomes, and (2) some pesticide compounds are linked to specific causes of female infertility, such as premature ovarian insufficiency, polycystic ovarian syndrome, and endometriosis. IVF participants living in agricultural regions should be informed about the fertility decline, low ongoing pregnancy rates, and elevated risk of miscarriage associated with exposure to high doses of pesticides.

In vitro and in vivo impairment of embryo implantation by commonly used fungicide Mancozeb

The fungicide Mancozeb is an endocrine-disrupting chemical and the mode of action of Mancozeb on embryo implantation is largely unknown. Mancozeb (1 and 3 μg/ml) significantly reduced Jeg-3 trophoblastic spheroids attachment to endometrial epithelial Ishikawa cells. Mancozeb treatment from gestation day (GD) 1 to GD8 or from GD4 to GD8 significantly lowered the number of implantation sites with higher incidence of morphological abnormalities in the reproductive tissues. However, these were not seen in the treatment from GD1 to GD4. Mancozeb at 30 mg/kg BW/d did not alter the expression of p53, COX-2, or PGFS transcripts in the uterus, but down-regulated the PGES transcript and protein. Mancozeb treatment in human endometrial stromal cells did not alter the decidualization response, but the morphological transformation was impaired. Taken together, exposure to Mancozeb affected embryo implantation probably through the modulation of decidualization and to delineate the exact mode of action needs further investigations.

Prenatal exposure to the pesticide metam sodium induces sensorimotor and neurobehavioral abnormalities in mice offspring

The present study has investigated developmental neurotoxicity of Metam sodium (MS), from gestational day 6 and throughout the gestation period until delivery. Therefore, mated female mice were orally exposed on a daily basis to 0 (control), 50, 100 or 150 mg of MS/kg of body weight and their standard fertility and reproductive parameters were assessed. The offspring were examined for their sensorimotor development, depression and cognitive performance. Our results showed that MS exposure during pregnancy led to one case of mortality, two cases of abortion and disturbed fertility and reproductive parameters in pregnant dams. In offspring, MS induced an overall delay in innate reflexes and sensorimotor performances. Furthermore, all prenatally treated animals showed an increased level of depression-like behavior as well as a pronounced cognitive impairment in adulthood. These results demonstrated that prenatal exposure to MS causes a long-lasting developmental neurotoxicity and alters a wide range of behavioral functions in mice.

Mancozeb exposure during development and lactation periods results in decreased oocyte maturation, fertilization rates, and implantation in the first-generation mice pups: Protective effect of vitamins E and C

This study aimed to evaluate the mancozeb (MNZ) impact on oocyte maturation of first-generation mice pups as well as their fertilization rate, embryo development, and implantation along with the preventative effect of vitamins E and C. Pregnant mice were randomly divided into six groups: control, vehicle, and MNZ (500 mg/kg body weight (BW)), vitamin E (200 mg/kg BW), MNZ plus vitamin E, MNZ plus vitamin C (100 mg/kg BW), and MNZ plus two vitamins. All treatments were conducted by oral gavage every 2 days from the second day of gestation until the end of lactation. Vitamin treatment was initiated 30 min before receiving MNZ. After birth, first-generation mice pups were kept until adulthood (8-10 W). Adult female mice pups superovulated and then the collected oocytes were examined for nuclear maturity status. After in vitro fertilization of metaphase II oocytes with sperm of the first-generation male mice pups, fertilization rate and embryo development were evaluated over 24 h. Also, the fecundity rate and the number of implanted embryos in vivo were studied on the eighth day of pregnancy. MNZ exposure during embryo development and lactation significantly decreased the total number of collected oocytes, oocyte maturation, fertilization rate, implantation rate, fecundity rate, and embryo development compared with the control group in the first-generation pups. In contrast, vitamin treatments significantly increased these parameters compared to the MNZ group. Reduction in the quality of oocyte, the rate of fertilization, embryo implantation, and development following MNZ exposure could decrease female reproductive success, while coadministration of vitamins E and C could prevent these complications.

Preventative Effects of Vitamin E on Testicular Damage and Sperm Parameters in the First-Generation Mice Pups due to Pre- and Postnatal Mancozeb Exposure

The present study aimed to evaluate the effects of vitamin E on mancozeb-induced testis damage of the first-generation pups during intrauterine and lactating periods. Two groups of pregnant NMRI mice received 500 mg/kg mancozeb (MNZ) as MNZ group and 200 mg/kg vitamin E as MNZ+vit.E group before receiving MNZ. In addition, a vehicle and a control group were designed every other day in gestation and lactation periods. The male pups from each group were maintained until adulthood (8-10 W). The left testes and epididymides were removed following the sacrifice of the pups. Then, they were weighed, and sperm parameters including number, viability, motility, and morphology and testis structure were evaluated. A significant decrease occurred in sperm parameters of the mancozeb-treated pups compared to the control and vehicle groups. Treatment with vitamin E reversed the deleterious effects of MNZ to a nearly normal condition. Testis parameters including the weight, gonadosomatic index, seminiferous tubule diameters, and Johnsen's score, as well as the number of germ cells such as spermatogonia, spermatocyte, spermatid, and Sertoli, decreased significantly in the MNZ group, compared to the amount in the control and vehicle groups. Interestingly, the treatment with vitamin E was reversed in most of these parameters. Based on the results, the exposure of pups to mancozeb during pregnancy and lactating periods negatively affects the reproductive system of male pups. However, the coadministration of vitamin E could prevent the deleterious effects of mancozeb on sperm and testis parameters.

Mancozeb impaired male fertility in rabbits with trials of glutathione detoxification

The study aims to evaluate the potential reproductive toxicity induced by mancozeb fungicide in male rabbits and to examine the ameliorative effect of glutathione (GSH), a non-enzymatic antioxidant, against mancozeb reproductive toxicity. Mancozeb is a member of the dithiocarbamates group currently in use in the management of fungal diseases of plants. To achieve these aims, mature male White New-Zealand rabbits of 4-5 months old were randomly assigned to four groups of 9 animals each: control, mancozeb only, mancozeb and GSH, and GSH only. This study discovered a significant reduction in serum FSH, LH, testosterone and testicular LDH, ACP, and ALP levels in the groups of mancozeb-treated rabbits compared with control. The mancozeb-treated groups also showed significant losses in sperm viability, along with a significant increase in the number of abnormal sperms. Finally, an upregulation in steroidogenic 3β-HSD enzyme activity was noted in mancozeb-treated rabbits. Histopathological inspection of the testicles established disruption of the germinal epithelium with vacuolization of Leydig cells and reduced spermatogenic cells. GSH co-administration increased serum concentrations of FSH, LH, testosterone, and levels of the testicular enzymes: LDH, ACP, and ALP. Improved steroidogenesis was indicated in this group by a significant improvement in the testicular 3β-HSD enzyme, by a significant increase in sperm viability, and by a significant decrease in the number of abnormal sperms. The findings of this study suggest that mancozeb exposure has anti-spermatogenic and anti-steroidogenic adverse effects in rabbits and administration of GSH may alleviate the reproductive toxicity.

Technologies for the Production of Fertilizable Mammalian Oocytes

Women affected by ovarian pathologies or with cancer can usually preserve fertility by egg/embryo freezing. When oocyte retrieval is not feasible, the only option available is ovarian tissue cryopreservation and transplantation. The culture of follicles isolated from fresh or cryopreserved ovaries is considered still experimental, although this procedure is considered safer, because the risk of unintentional spreading of cancer cells eventually present in cryopreserved tissue is avoided. Animal and human small follicles can be cultured in vitro, but standardized protocols able to produce in vitro grown oocytes with the same developmental capacity of in vivo grown oocytes are not available yet. In fact, the different sizes of follicles and oocytes, the hormonal differences existing between mono- (e.g., human, goat, cow, and sheep) and poly-ovulatory (rodents and pig) species, and the incomplete identification of the mechanisms regulating the oocyte–follicle and follicle–ovary interrelationships affect the outcome of in vitro culture. From all these attempts, however, new ideas arise, and the goal of assuring the preservation of female reproductive potential appears a more realistic possibility. This review surveys and discusses advances and challenges of these technologies that, starting from a simple attempt, are now approaching the biosynthesis of a functional engineered ovary.

Hazardous effects of chemical pesticides on human health-Cancer and other associated disorders

Poisoning from pesticides is a global public health problem and accounts for nearly 300,000 deaths worldwide every year. Exposure to pesticides is inevitable; there are different modes through which humans get exposed to pesticides. The mode of exposure is an important factor as it also signifies the concentration of pesticides exposure. Pesticides are used extensively in agricultural and domestic settings. These chemicals are believed to cause many disorders in humans and wildlife. Research from past few decades has tried to answer the associated mechanism of action of pesticides in conjunction with their harmful effects. This perspective considers the past and present research in the field of pesticides and associated disorders. We have reviewed the most common diseases including cancer which are associated with pesticides. Pesticides have shown to be involved in the pathogenesis of Parkinson's and Alzheimer's diseases as well as various disorders of the respiratory and reproductive tracts. Oxidative stress caused by pesticides is an important mechanism through which many of the pesticides exert their harmful effects. Oxidative stress is known to cause DNA damage which in turn may cause malignancies and other disorders. Many pesticides have shown to modulate the gene expression at the level of non-coding RNAs, histone deacetylases, DNA methylation patterns suggesting their role in epigenetics.

Dietary Exposure to Tebuconazole Affects Testicular and Epididymal Histomorphometry in Frugivorous Bats

This study evaluated the effects of a commercially recommended concentration (1 mL/L) of a fungicide tebuconazole (TBZ) on testicular and epididymal histomorphometry of Artibeus lituratus, following 7 and 30-day oral exposure. TBZ30 bats showed a reduction in the percentage of tubules and seminiferous epithelium, as well as a decrease in tubule and epithelium somatic indexes, and tubular diameter. Inversely, these animals showed increased percentage of intertubular compartment, Leydig cells and blood vessels. The volume of Leydig cells and their number per gram of testis also increased in TBZ30 bats. Alterations in epididymal morphometry were observed in all regions of the organ, with increase of ductal diameter in both exposure times. These results indicate that exposure to low concentration of TBZ resulted in testicular and epididymal morphometric changes in fruit bats, mainly at 30-day exposure, suggesting that functional alterations might be occurring in these organs and impacting reproductive capacity.

Environmental and biological monitoring for the identification of main exposure determinants in vineyard mancozeb applicators

Grapevine is a vulnerable crop to several fungal diseases often requiring the use of ethylenebisdithiocarbamate (EBDC) fungicides, such as mancozeb. This fungicide has been reported to have goitrogenic, endocrine disrupting, and possibly immunotoxic effects. The aim of this study was to assess workers' exposure in two scenarios of mancozeb application and analyse the main determinants of exposure in order to better understand their mechanism of influence. Environmental monitoring was performed using a modified Organisation for Economic Co-operation and Development (OECD) "patch" methodology and by hand-wash collection, while mancozeb's metabolite, ethylenethiourea (ETU), was measured in 24-h preexposure and postexposure urine samples. Liquid chromatography-mass spectrometry was used for determination of mancozeb and ETU in different kinds of samples. Closed tractor use resulted in 40 times lower potential exposure compared with open tractor. Coveralls reduced skin exposure 4 and 10 times in case of open and closed tractors, respectively. Gloves used during application resulted in 10 times lower hand exposure in open but increased exposure in closed tractors. This study has demonstrated that exposure to mancozeb is low if safe occupational hygiene procedures are adopted. ETU is confirmed as suitable biological marker of occupational exposure to mancozeb, but the absence of biological exposure limits significantly reduces the possibility to interpret biological monitoring results in occupationally exposed workers.

Effects of mancozeb, metalaxyl and tebuconazole on steroid production by bovine luteal cells in vitro

Mancozeb, metalaxyl and tebucanazole are widely used pesticides in agriculture and industry to treat plant pathogenic fungi. Livestock may be exposed to such substances by consuming contaminated plants. The present study was designed to evaluate the effects of these three fungicides on bovine luteal cell steroidogenesis. Luteal slices from mid-cycle corpus luteum were dissociated into single cell suspension in aerated (O₂) culture media (DMEM/F12) by enzymatic digestion. The cells were incubated in newborn calf serum (10%) for 18 h and then with serum-free media containing mancozeb (0.01 μM, 0.1 μM, 1 μM), tebuconazole (1 μM, 10 μM, 100 μM) or metalaxyl (100 μM, 500 μM, 2500 μM) for additional 96 h. The medium was replaced on day 1 and 3; and the retrieved medium was stored at -20 °C until progesterone assay. Treatment of cells with three different fungicides induced dose dependent variable decrease in steroid synthesis during incubation periods. Incubation of cells with 1 μM mancozeb exhibited a 33% decline in steroid synthesis on day 3 and 48% decline on day 5 compared with controls. Treatment of cells with 100 μM tebuconazole and 500 μM metalaxyl resulted in a 65% and 31% decrease, respectively, in progesterone accumulation on day 5 of incubation. Fungicide induced suppressive effects on luteal steroidogenesis were as metalaxyl < tebuconazole < mancozeb. Results of the present study suggest that designated concentrations of all three fungicides studied might have varying degrees of adverse effects on luteal steroidogenesis.

Protective effects of resveratrol against mancozeb induced apoptosis damage in mouse oocytes

Mancozeb, a mixture of ethylene-bis-dithiocarbamate manganese and zinc salts, is one of the most widely used fungicides in agriculture. Mancozeb could lead to mitochondria dysfunction, cellular anti-oxidation enzymes depletion and apoptotic pathways activation. Previous studies indicated the exposure of mancozeb through mother would lead to irregular estrous cycles, decreased progesterone levels, reduced litter sizes, and more frequent delivery of dead fetuses. In this study, we investigated mancozeb inducing reproductive toxicity, especially focusing on its apoptotic effect and epigenetic modifications. We also showed that resveratrol, a kind of phytoalexin found in peanuts and grapes, can alleviate mancozeb's adverse effects, such as declined fertility, decreased ovary weight and primary follicles. Besides, mancozeb treated oocytes displayed suboptimal developmental competence and this can also be improved by treatment of resveratrol. More detailed investigation of these processes revealed that mancozeb increased reactive oxygen species, causing cell apoptosis and abnormal epigenetic modifications, and resveratrol can block these cytotoxic changes. Collectively, our results showed that resveratrol can alleviate mancozeb induced infertility and this was mainly through the correction of apoptotic tendency and the abnormity of cellular epigenetic modification.

ROS-dependent Bax/Bcl2 and caspase 3 pathway-mediated apoptosis induced by zineb in human keratinocyte cells

There are a large number of agricultural workers who are exposed to pesticides through skin and inhalation. The best approach to identify altered molecular pathways during dermal exposure to pesticides is relevant to risk-associated concern about skin safety. In this study, we investigated the cytotoxic effect of zineb, a fungicide, in human keratinocyte (HaCaT) cells. HaCaT cells were treated with zineb (1–40 µg/mL) for 24 hours. Cellular and molecular mechanisms of cell toxicity were investigated through MTT and neutral red-uptake assays. Zineb reduced viability of HaCaT cells and induced apoptosis in a concentration-dependent manner. Zineb increased levels of Bax and caspase 3 and inhibited the level of Bcl2, which subsequently induced apoptosis via the Bax/Bcl2 and caspase pathway. Therefore, zineb could have induced apoptosis through the mitochondrial pathway in HaCaT cells. Our study suggests that zineb is cytotoxic to HaCaT cells via the induction of apoptosis and oxidative stress in vitro.

Mancozeb impairs the ultrastructure of mouse granulosa cells in a dose-dependent manner

Mancozeb, an ethylene bis-dithiocarbamate, is widely used as a fungicide and exerts reproductive toxicity in vivo and in vitro in mouse oocytes by altering spindle morphology and impairing the ability to fertilize. Mancozeb also induces a premalignant status in mouse granulosa cells (GCs) cultured in vitro, as indicated by decreased p53 expression and tenuous oxidative stress. However, the presence and extent of ultrastructural alterations induced by mancozeb on GCs in vitro have not yet been reported. Using an in vitro model of reproductive toxicity, comprising parietal GCs from mouse antral follicles cultured with increasing concentrations of mancozeb (0.001–1 µg/ml), we sought to ascertain the in vitro ultrastructural cell toxicity by means of transmission (TEM) and scanning (SEM) electron microscopy. The results showed a dose-dependent toxicity of mancozeb on mouse GCs. Ultrastructural data showed intercellular contact alterations, nuclear membrane irregularities, and chromatin marginalization at lower concentrations, and showed chromatin condensation, membrane blebbing, and cytoplasmic vacuolization at higher concentrations. Morphometric analysis evidenced a reduction of mitochondrial length in GCs exposed to mancozeb 0.01−1 µg/ml and a dose-dependent increase of vacuole dimension. In conclusion, mancozeb induced dose-dependent toxicity against GCs in vitro, including ultrastructural signs of cell degeneration compatible with apoptosis, likely due to the toxic breakdown product ethylenethiourea. These alterations may represent a major cause of reduced/delayed/missed oocyte maturation in cases of infertility associated with exposure to pesticides.

A systematic review of Mancozeb as a reproductive and developmental hazard

BACKGROUND

The potential adverse reproductive and developmental effects of Mancozeb, especially in sensitive subpopulations, have not been fully reviewed for this widely used fungicide.

OBJECTIVE

To review the experimental and epidemiologic evidence for the association between exposure to Mancozeb and reproductive and developmental health outcomes using an adaptation of the National Toxicology Program's Office of Health Assessment and Translation (OHAT) systematic review framework.

DATA SOURCES

Four databases (PubMed, TOXNET, Web of Science, Google Scholar) were searched for published studies on Mancozeb. Of 403 identified articles, 30 met our inclusion criteria for systematic review.

RESULTS

Results from in vitro studies provide evidence that Mancozeb may indirectly disrupt or impair reproduction at the cellular level and should be regarded as a reproductive toxicant. Animal studies confirm reproductive and developmental toxicity in mammals and suggest that males chronically exposed to Mancozeb experience significant changes in physiological, biochemical, and pathological processes that may lead to infertility. Epidemiological studies were limited to indirect methods of exposure assessment and examined the effect of fungicides more broadly during pre-conception, pregnancy, and birth, yielding mixed results.

CONCLUSIONS

High confidence ratings from in vitro and animal studies, in combination with moderate confidence ratings from epidemiologic studies employing indirect methods of exposure assessment, provide evidence that Mancozeb should be regarded as a suspected developmental hazard and a presumed reproductive hazard in humans. More population-based studies linking direct measures and/or biomarkers of exposure to adverse effects on male and female fertility, as well as in utero and early life development, are needed to improve the quality of the evidence base concerning the human reproductive and developmental consequences of Mancozeb exposure.

Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

Mancozeb affects mitochondrial activity, redox status and ATP production in mouse granulosa cells

BACKGROUND

Mancozeb (MZ) is a fungicide that belongs to the subclass of metal (Mn/Zn) ethylene-bis-dithiocarbamate pesticides. In mouse and human granulosa cells (GCs) exposed to MZ (0.01 μg/ml), morphological modifications and significant alterations of p53 expression level in comparison with control GCs were recorded.

OBJECTIVES

To investigate if MZ (0.01 μg/ml) induces oxidative stress and alters energy metabolism in exposed mouse GCs.

RESULTS

Following fungicide exposure, GCs showed low p53 content, a depolarized mitochondrial membrane potential (ΔΨm), as well as low ATP and reduced glutathione (GSH) levels associated with increased reactive oxygen species (ROS) generation. No remarkable differences on other parameters such as ATP/ADP ratio, energy charge, as well as induction of apoptosis and DNA damage were found. The activation of AKT and PDK1 kinases in MZ-treated cells was observed. Inhibition of ROS generation by the antioxidant N-acetylcysteine (NAC) restored a normal expression level of p53.

CONCLUSIONS

Our results demonstrate that the low dose of MZ here used induces a mild oxidative stress in GCs, and provides evidence for the possible involvement of AKT/PKB signaling pathway in triggering adaptive and survival response.

High-throughput method for the analysis of ethylenethiourea with direct injection of hydrolysed urine using online on-column extraction liquid chromatography and triple quadrupole mass spectrometry

Ethylenethiourea (ETU) is of major toxicological concern, since in experimental animal studies, ETU has shown a large spectrum of adverse effects. High occupational exposure can be found among agricultural workers or during manufacturing of ethylenbisdithiocarbamates (EBDC). For the general public, sources of environmental exposure may be residues of ETU in commercial products, food and beverages. For the determination of ETU in human urine we present a high-throughput online on-column extraction liquid chromatography triple quadrupole mass spectrometry method using direct injection of hydrolysed urine samples. This method is simple, user- and environmentally friendly and all sample preparation is performed in 96-well plates. A labelled ETU internal standard was used for quantification. The method showed a good sensitivity with a limit of quantification (LOQ) of 0.5ng ETU/mL urine and the calibration curve was linear in the range 0.25-200ng ETU/mL urine. The within-run, between-run and between-batch precision was between 6% and 13%. Alkaline hydrolysis considerably increased the levels of ETU indicating a potential conjugate. The method was applied in an experimental dermal exposure study in humans, with sample concentrations ranging from 0.4 to 5.0ng ETU/mL urine. The excretion in urine was 10% of the applied dose. The elimination profile seemed to differ between the two individuals. The results show an estimated half-life of ETU between 34 and 72h. Although the experiment is limited to two individuals, the data provide valuable and new information regarding the toxicokinetics of ETU after dermal exposure.

In vivo and in vitro environmental effects on mammalian oocyte quality

The oocyte is at the center of the equation that results in female fertility. Many factors influence oocyte quality, including external factors such as maternal nutrition, stress, and environmental exposures, as well as ovarian factors such as steroids, intercellular communication, antral follicle count, and follicular fluid composition. These influences are interconnected; changes in the external environment of the female translate into ovarian changes that affect the oocyte. The lengthy period during which the oocyte remains arrested in the ovary provides ample time and opportunity for environmental factors to take their toll. An appropriate environment for growth and maturation of the oocyte, in vivo and in vitro, is critical to ensure optimal oocyte quality, which determines the success of fertilization and preimplantation embryo development, and has long-term implications for implantation, fetal growth, and offspring health.

Quercetin protected isolated human erythrocytes against mancozeb-induced oxidative stress

Mancozeb is a fungicide belonging to the ethylene-bisdithiocarbamate group and is widely used in agriculture. The aim of this study was to examine the protective effect of quercetin (QRN) against oxidative stress induced by mancozeb in human erythrocytes. In order to verify this, 5 ml of venous blood was collected and the erythrocytes were separated and divided into equal parts. One part was incubated with different concentrations of mancozeb (0, 10, 30, 100 µM) for 4 h at 37°C. The other part was preincubated with QRN (40 and 80 μM) for 30 min, followed by mancozeb (0, 10, 30, 100 µM) incubation for 4 h. We found reduction in the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) along with elevated levels of lipid peroxide (LPO) in erythrocytes incubated with 30 and 100 µm of mancozeb. Pre-incubation with QRN (80 μM) reversed oxidative stress induced by mancozeb (30 μM) and inhibited LPO induced at 100 μM by 64.36%. QRN also reduced the haemolytic effect on erythrocytes but could not prevent the induction of haemolysis by mancozeb. Therefore, these results suggest that QRN may play a role in preventing the oxidative stress induced by mancozeb in human erythrocytes.

Does the oestrogen receptor encourage oestrogenicity in environmental pollutants? The case of 4-nonylphenol

A computer-aided docking study was conducted to explore in detail the binding interactions between the structurally unlikely environmental oestrogen 4-nonylphenol (4NP) and three of its metabolites with the human oestrogen receptor alpha (hERα). Docking was done within the Schrodinger Suite 2008 using both a conventional rigid receptor with flexible ligand and the induced-fit docking protocol. Induced-fit docking allows side-chain and backbone movement in the receptor to accommodate the ligand. This study has revealed unconventional interactions between the ligands and the hERα binding pocket that could explain the observed oestrogen-like behaviour of 4NP and suggests some of the metabolites of 4NP may also be oestrogenic.

Analysis of ethylenethiourea as a biomarker in human urine using liquid chromatography/triple quadrupole mass spectrometry

Ethylenebisdithiocarbamates (EBDCs) are widely used fungicides. Ethylenethiourea (ETU), the main metabolite and also a contaminant in the commercially available products, is of major toxicological concern. In this study, a method using liquid chromatography/triple quadrupole mass spectrometry (LC/MS/MS) is described for the analysis of ETU in human urine after a single-step extractive derivatization using pentafluorobenzyl bromide (PFBBr). Analysis was carried out using selected reaction monitoring (SRM) in the positive ion mode. Quantification of ETU was performed using [(2)H(4)]-labeled ETU as internal standard (IS). The limit of detection (LOD) was determined to 0.05 ng/mL. The method was linear in the range 0.1-54 ng/mL urine and had a within-run precision of 3-5%. The between-run precision was determined at an average urine level of 2 and 10 ng/mL urine and found to be 9%. The inter-batch precision was 6%. To validate ETU as a biomarker of exposure, the method was applied in a human experimental oral exposure to the commercial fungicide Ridomil Gold, containing 64% mancozeb and 4.5% ETU. Two healthy volunteers received 8.9 microg/kg body weight (b.w.) Ridomil Gold in a single oral dose followed by urine sampling for 104 h post-exposure. The elimination half-life of ETU was estimated to 17-23 h.