Pesticide chlorpyrifos acts as an endocrine disruptor in adult rats causing changes in mammary gland and hormonal balance

Chlorpyrifos induces autophagy by suppressing the mTOR pathway in immortalized GnRH neurons

Chlorpyrifos (CPF) is a widely used pesticide inducing adverse neurodevelopmental and reproductive effects. However, knowledge of the underlying mechanisms is limited, particularly in the hypothalamus. We investigated the mode of action of CPF at human relevant concentrations (1 nM-100 nM) in immortalized mouse hypothalamic GnRH neurons (GT1-7), an elective model for studying disruption of the hypothalamus-pituitary-gonads (HPG) axis. We firstly examined cell vitality, proliferation, and apoptosis/necrosis. At not-cytotoxic concentrations, we evaluated neuron functionality, gene expression, Transmission Electron Microscopy (TEM) and proteomics profiles, validating results by immunofluorescence and western blotting (WB). CPF decreased cell vitality with a dose-response but did not affect cell proliferation. At 100 nM, CPF inhibited gene expression and secretion of GnRH; in addition, CPF reduced the immunoreactivity of the neuronal marker Map2 in a dose-dependent manner. The gene expression of Estrogen Receptor α and β (Erα, Erβ), Androgen Receptor (Ar), aromatase and oxytocin receptor was induced by CPF with different trends. Functional analysis of differentially expressed proteins identified Autophagy, mTOR signaling and Neutrophil extracellular traps (NETs) formation as significant pathways affected at all concentrations. This finding was phenotypically supported by the TEM analysis, showing marked autophagy and damage of mitochondria, as well as by protein analysis demonstrating a dose-dependent decrease of mTOR and its direct target pUlk1 (Ser 757). The bioinformatics network analysis identified a core module of interacting proteins, including Erα, Ar, mTOR and Sirt1, whose down-regulation was confirmed by WB analysis. Overall, our results demonstrate that CPF is an inhibitor of the mTOR pathway leading to autophagy in GnRH neurons; a possible involvement of the Erα/Ar signaling is also suggested. The evidence for adverse effects of CPF in the hypothalamus in the nanomolar range, as occurs in human exposure, increases concern on potential adverse outcomes induced by this pesticide on the HPG axis.

Exposure to Pesticides and Breast Cancer in an Agricultural Region in Brazil

Rural workers are disproportionally exposed to pesticides and might be at an increased risk of developing chronic diseases. Here, we investigated the impact of pesticide exposure on breast cancer (BC) risk and disease profile in rural female workers. This is a case-control study that prospectively included 758 individuals. The study was conducted in the Southwest region of Paraná state in Brazil, a region characterized by family-based agriculture and intensive use of pesticides. We found that this region has a 41% higher BC diagnosis rate and 14% higher BC mortality rate than the mean rates in Brazil, as well as a pesticide trade volume about 6 times higher than the national average. We showed substantial exposure in this population and found that even women who did not work in the fields but performed equipment decontamination and clothes washing of male partners who worked in the fields had urine samples positive for glyphosate, atrazine, and/or 2,4-D. The crude association showed a significantly higher risk of BC among women exposed to pesticides (OR: 1.58, 95% CI 1.18-2.13). Adjusted analyses showed a lower and nonstatistically significant association (OR: 1.30, 95% CI 41 0.87-1.95). Stratification on disease profile showed a significantly higher risk of lymph node metastasis (adjusted OR: 2.19, 95% CI 1.31-3.72) in women exposed to pesticides. Our findings suggest that female populations exposed to pesticides are at a higher risk of developing BC with a more aggressive profile and draw attention to the need to monitor rural populations potentially exposed to pesticides in the field or at home.

Investigating the prevalence of erectile dysfunction among men exposed to organophosphate insecticides

INTRODUCTION

Erectile dysfunction (ED) poses a significant disease morbidity and contributor to male infertility, where an estimated 20-40% of men are affected annually. While several risk factors have been identified in the etiology of ED (e.g., aging, heart disease, diabetes, and obesity), the complete pathogenesis remains to be elucidated. Over the last few decades, the contribution of environmental exposures to the pathogenesis of ED has gained some attention, though population studies are limited and results are mixed. Among environmental contaminants, organophosphate (OP) insecticides represent one of the largest chemical classes, and chlorpyrifos is the most commonly used OP in the U.S. OP exposure has been implicated in driving biological processes, including inflammation, reactive oxygen species production, and endocrine and metabolism disruption, which have been demonstrated to adversely affect the hypothalamus and testes and may contribute to ED. Currently, studies evaluating the association between OPs and ED within the U.S. general population are sparse.

METHODS

Data were leveraged from the National Health and Nutrition Examination Survey (NHANES), which is an annually conducted, population-based cross-sectional study. Urinary levels of 3,5,6-trichloro-2-pyridinol (TCPy), a specific metabolite of the most pervasive OP insecticide chlorpyrifos, were quantified as measures of OP exposure. ED was defined by responses to questionnaire data, where individuals who replied "sometimes able" or "never able" to achieve an erection were classified as ED. Chi-square, analysis of variance (ANOVA), and multivariable, weighted linear and logistic regression analyses were used to compare sociodemographic variables between quartiles of TCPy exposure, identify risk factors for TCPy exposure and ED, and to analyze the relationship between TCPy and ED.

RESULTS

A total of 671 adult men were included in final analyses, representing 28,949,379 adults after survey weighting. Approximately 37% of our cohort had ED. Smoking, diabetes, aging, Mexican-American self-identification, and physical inactivity were associated with higher ED prevalence. Analysis of TCPy modeled as a continuous variable revealed nonsignificant associations with ED (OR = 1.02 95% CI [0.95, 1.09]). Stratification of total TCPy into quartiles revealed increased odds of ED among adults in the second and fourth quartiles, using the first quartile as the reference (OR = 2.04 95% CI [1.11, 3.72], OR = 1.51 95% CI [0.58, 3.93], OR = 2.62 95% CI [1.18, 5.79], for quartiles 2, 3, and 4, respectively).

CONCLUSIONS

The results of our study suggest a potential role for chlorpyrifos and other OPs the pathogenesis of ED. Future studies are warranted to validate these findings, determine clinical significance, and to investigate potential mechanisms underlying these associations.

Non-target estrogenic screening of 60 pesticides, six plant protection products, and tomato, grape, and wine samples by planar chromatography combined with the planar yeast estrogen screen bioassay

For non-target residue analysis of xenoestrogens in food, sophisticated chromatographic-mass spectrometric techniques lack in biological effect detection. Various in vitro assays providing sum values encounter problems when opposing signals are present in a complex sample. Due to physicochemical signal reduction, cytotoxic or antagonistic effect responses, the resulting sum value is falsified. Instead, the demonstrated non-target estrogenic screening with an integrated planar chromatographic separation differentiated opposing signals, detected and prioritized important estrogenic compounds, and directly assigned tentatively the responsible compounds. Sixty pesticides were investigated, ten of which showed estrogenic effects. Exemplarily, half-maximal effective concentrations and 17β-estradiol equivalents were determined. Estrogenic pesticide responses were confirmed in six tested plant protection products. In food, such as tomato, grape, and wine, several compounds with an estrogenic effect were detected. It showed that rinsing with water was not sufficient to remove selected residues and illustrated that, though not usually performed for tomatoes, peeling would be more appropriate. Though not in the focus, reaction or breakdown products that are estrogenic were detected, underlining the great potential of non-target planar chromatographic bioassay screening for food safety and food control.

Differential effects of pesticides on dioxin receptor signaling and p53 activation

As modern agricultural practices increase their use of chemical pesticides, it is inevitable that we will find a number of these xenobiotics within drinking water supplies and disseminated throughout the food chain. A major problem that arises from this pollution is that the effects of most of these pesticides on cellular mechanisms in general, and how they interact with each other and affect human cells are still poorly understood. In this study we make use of cultured human cancer cells to measure by qRT-PCR how pesticides affect gene expression of stress pathways. Immunoblotting studies were performed to monitor protein expression levels and activation of signaling pathways. We make use of immunofluorescence and microscopy to visualize and quantify DNA damage events in those cells. In the current study, we evaluate the potential of a subset of widely used pesticides to activate the dioxin receptor pathway and affect its crosstalk with estrogen receptor signaling. We quantify the impact of these chemicals on the p53-dependent cellular stress response. We find that, not only can the different pesticides activate the dioxin receptor pathway, most of them have better than additive effects on this pathway when combined at low doses. We also show that different pesticides have the ability to trigger crosstalk events that may generate genotoxic estrogen metabolites. Finally, we show that some, but not all of the tested pesticides can induce a p53-dependent stress response. Taken together our results provide evidence that several xenobiotics found within the environment have the potential to interact together to elicit significant effects on cell systems. Our data warrants caution when the toxicity of substances that are assessed simply for individual chemicals, since important biological effects could be observed only in the presence of other compounds, and that even at very low concentrations.

Interplay between Estrogen, Kynurenine, and AHR Pathways: An immunosuppressive axis with therapeutic potential for breast cancer treatment

Breast cancer is one of the most common malignancies among women worldwide. Estrogen exposure via endogenous and exogenous sources during a lifetime, together with environmental exposure to estrogenic compounds, represent the most significant risk factor for breast cancer development. As breast tumors establish, multiple pathways are deregulated. Among them is the aryl hydrocarbon receptor (AHR) signaling pathway. AHR, a ligand-activated transcription factor associated with the metabolism of polycyclic aromatic hydrocarbons and estrogens, is overexpressed in breast cancer. Furthermore, AHR and estrogen receptor (ER) cross-talk pathways have been observed. Additionally, the Tryptophan (Trp) catabolizing enzymes indolamine-2,3-dioxygenase (IDO) and tryptophan-2,3-dioxygenase (TDO) are overexpressed in breast cancer. IDO/TDO catalyzes the formation of Kynurenine (KYN) and other tryptophan-derived metabolites, which are ligands of AHR. Once KYN activates AHR, it stimulates the expression of the IDO enzyme, increases the level of KYN, and activates non-canonical pathways to control inflammation and immunosuppression in breast tumors. The interplay between E2, AHR, and IDO/TDO/KYN pathways and their impact on the immune system represents an immunosuppressive axis on breast cancer. The potential modulation of the immunosuppressive E2-AHR-IDO/TDO/KYN axis has aroused great expectations in oncotherapy. The present article will review the mechanisms implicated in generating the immunosuppressive axis E2-AHR-IDO/TDO/KYN in breast cancer and the current state of knowledge as a potential therapeutic target.

Pesticides in sediments from Magdalena River, Colombia, are linked to reproductive toxicity on Caenorhabditis elegans

Pesticides are prevalent pollutants found in river sediments in agricultural regions worldwide, leading to environmental pollution and toxic effects on biota. In this study, twenty sediment samples were collected from the Magdalena River in Colombia and analyzed for forty pesticides. Methanolic extracts of the sediments were used to expose Caenorhabditis elegans for 24 h, evaluating the effects on its reproduction. The most abundant pesticides found in Magdalena River sediments were atrazine, bromacil, DDE, and chlorpyrifos. The concentrations of DDE and the sum of DDD, DDE, and DDT were above the Threshold Effect Concentration (TEC) values for freshwater sediments, indicating potential effects on aquatic organisms. The ratios of DDT/(DDE + DDD) and DDD/DDE suggest historical contributions of DDT and degradation under aerobic conditions. Several sampling sites displayed a moderate toxicity risk to biota, as calculated by the sediment quality guideline quotient (SQGQ). Nematode brood size was reduced by up to 37% after sediment extract exposure. The presence of chlordane, DDT-related compounds, and chlorpyrifos in Magdalena River sediments was associated with reproductive toxicity among C. elegans.

Exposure to pesticide residues in honey and its potential cancer risk assessment

Honey is the most recognized natural food by-product derived from flower nectar and the upper aero-digestive tract of the honeybees. Significance of honey for its medicinal importance are well-documented in the world's oldest medical literatures. However, the current urbanization, environmental contaminations and changes in agricultural, as well as apiculture practices has led to various types of contaminations in honey. Among all, pesticide contamination has become one of the major issues worldwide. This review focuses on the recent updates concerning pesticides occurrence in honey, as well as how the repeated use and long-term exposure to honey contaminated with pesticide residues could affect the human physiological functions, possibly leading to the development of various cancers. Our findings suggests that uncontrolled use of pesticides in farming and apiculture practices leads to the occurrence of pesticides residues in honey. Therefore, regular consumption of such honey will pose a serious threat to human health, since most of the pesticides has been reported as potential carcinogens. This review will draw the attention of honey consumers, scientific communities, apiculture farmers, as well as governing bodies to strictly monitor the pesticide usage in floriculture, agriculture as well as other related practices.

Methylated and ethylated dialkylphosphate metabolites of organophosphate pesticides: DNA damage in bone marrow cells of Balb/c mice

Dialkylphosphates (DAPs), metabolites of organophosphate (OP) pesticides, are widely distributed in the environment and are often used as biomarkers of OP exposure. Recent reports indicate that DAPs may be genotoxic, both in vitro and in vivo. We have examined the genotoxicity of the methylated DAPs dimethyldithiophosphate (DMDTP) and dimethylphosphate (DMTP) and the ethylated DAPs diethyldithiophosphate (DEDTP) and diethylphosphate (DETP), in comparison with their parental compounds, malathion and terbufos, respectively, in bone marrow polychromatic erythrocytes (PCE) of male and female Balb/c mice. We also compared DNA damage (comet assay) induced by DMDTP and dimethyl phosphate (DMP) in human cell lines. Both DMDTP and DMP caused DNA damage in peripheral blood mononuclear cells, HeLa cells, and the hepatic cell lines HepG2 and WRL-68. In the in vivo micronucleus assay, methylated and ethylated DAPs increased micronucleated PCE cells in both male and female mice. Female mice were more susceptible to DNA damage. In comparison to their parental compounds, methylated DAPs, particularly DMTP, were more genotoxic than malathion; DEDTP, DETP, and terbufos were similar in potency. These results suggest that DAPs may contribute to DNA damage associated with OP pesticide exposure.

The determinants of thyroid function among vegetable farmers with primary exposure to chlorpyrifos: A cross-sectional study in Central Java, Indonesia

Objectives

Occupational pesticide exposure, chlorpyrifos (CPF) in particular, may adversely affect the thyroid. The purpose of this study was to evaluate the determinants of thyroid function as indicated by the serum concentration of thyroid-stimulating hormone (TSH) among Indonesian vegetable farmers with primary exposure to CPF.

Methods

A total of 151 vegetable farmers participated in this study. The sociodemographic and occupational characteristics of the participants were obtained using a structured interviewer-administered questionnaire. A validated quantitative method was used to estimate the cumulative exposure level (CEL). Serum TSH, thyroglobulin (Tg), free thyroxine (FT4), and urinary iodine excretion (UIE) were measured in the laboratory. The difference in TSH concentrations according to CEL and other characteristics were analysed using the Mann-Whitney U test. A multiple linear regression model was used to evaluate the potential determinants of TSH.

Results

The mean age was 50 (SD 9.4) years. The median concentrations of TSH, FT4, and Tg/FT4 ratio were 1.46 mIU/L, 1.17 ng/dL, and 6.23 × 10², respectively. We observed that higher TSH concentrations were found among those with a higher Tg/FT4 ratio, were classified as high CEL, and had lower UIE or FT4.

Conclusions

Our findings show that Tg/FT4 ratio, CEL, FT4, UIE concentrations, and post-spraying days were determinants of TSH concentrations among farmers with primary exposure to CPF. These results indicate that farmers are exposed to agents with thyroid-disrupting properties, thus supporting previous evidence showing the potential for thyroid disorders in agricultural populations exposed to pesticides.

Improved charge-transfer resonance in graphene oxide/ZrO2 substrates for plasmonic-free SERS determination of methyl parathion

This work reports a sensitive SERS substrate based on graphene oxide (GO) and quantum-sized ZrO₂ nanoparticles (GO/ZrO₂) for label-free determination of the organophosphate pesticide methyl parathion (MP). The enhanced light-matter interactions and the consequent SERS effect in these substrates resulted from the effective charge transfer (CT) mechanism attributed to synergistic contributions of three main factors: i) the strong molecular adherence of the MP molecules and the ZrO₂ surface which allows the first layer-effect, ii) the relatively abundant surface defects in low dimensional ZrO₂ semiconductor NPs, which act as intermediate electronic states that reduce the large bandgap barrier, and iii) the hindered charge recombination derived from the transference of the photoinduced holes to the GO layer. This mechanism allowed an enhancement factor of 8.78 × 10⁴ for GO/ZrO₂-based substrates, which is more than 5-fold higher than the enhancement observed for platforms without GO. A detection limit of 0.12 μM was achieved with an outstanding repeatability (variation ≤4.5%) and a linear range up to 10 μM, which is sensitive enough to determine the maximal MP concentration permissible in drinking water according to international regulations. Furthermore, recovery rates between 97.4 and 102.1% were determined in irrigation water runoffs, strawberry and black tea extracts, demonstrating the reliability of the hybrid GO/ZrO₂ substrate for the organophosphate pesticides quantification in samples related to agri-food sectors and environmental monitoring.

Surveillance and dietary risk assessment of endocrine-disrupting pesticides in eggplant/brinjal and cauliflower in Pakistan

Several pesticides (used in vegetable production) have recently been identified as potential endocrine disruptors. The current study aimed to determine the consumer exposure risk associated with eating contaminated vegetables. The European Union-citrate buffered QuEChERS extraction protocol, validated in accordance with the European Union guidelines, was used to monitor selected endocrine-disrupting pesticides in eggplant/brinjal (Solanum melongena L.) and cauliflower (Brassica oleracea) marketed in Rawalpindi/Islamabad, Pakistan. A total of 80 and 69 percent of eggplant/brinjal (n = 25) and cauliflower (n = 26) samples were found contaminated, respectively. Sixty-five percent of cauliflower samples were found non-contaminated with both European Union (EU) and Codex Alimentarius Commission (CAC) maximum residue limits (MRL), while 20 % of brinjal samples were found to be non-compliant with EU-MRL. Both vegetables contained high levels of the androgen antagonist chlorpyrifos and the thyroid hormone inhibitor cyhalothrin-lambda. The estimated acute health risk associated with dietary exposure to chlorpyrifos and cyhalothrin-lambda in cauliflower for both males and females was found to be greater than 200 % of the FAO/WHO Joint Meeting on Pesticide Residues' (JMPR) established acute reference dose. The estimated chronic health risk for all studied endocrine-disrupting pesticides (0-5.27 %) indicates zero to very low health risk for studied population groups.

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.

How pesticides affect neonates? - Exposure, health implications and determination of metabolites

This review covers key information related to the effects of pesticides on fetal and child health. All humans are exposed to environmental toxicants, however child's health, due to their high vulnerability, should be of special concern. They are continuously exposed to environmental xenobiotics including a wide variety of pesticides, and other pollutants. These compounds can enter the child's body through various routes, both during fetal life, in the first days of life with breast milk, as well as during environmental exposure in later years of life. Consequently, in the body, some of them are metabolized and excreted with urine or faces, while others accumulate in tissues causing toxic effects. This review will provide information on the types of pesticides, their pathways of uptake and metabolism in children's bodies. Determination of the impact of them on children's organism performance is possible through effective identification of these compounds and their metabolites in children's tissues and biofluids. Therefore, the main procedures for the determination of pesticides are reviewed and future trends in this field are indicated. We believe that this comprehensive review can be a good starting place for the future readers interested in the impact of environmental xenobiotics on the health of children as well as the aspects relates with the analytical methods that can be used for analysis and monitoring of these pollutants in children's tissues and biofluids.

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.

Cocktail Effect of Endocrine Disrupting Chemicals: Application to Chlorpyrifos in Lavender Essential Oils

Chlorpyrifos is a pesticide that is toxic to human health and has been banned for the past decade. Due to its persistent and bioaccumulative properties, chlorpyrifos is still present in soil. Pregnant women can be exposed to chlorpyrifos through drinking water and herbal products, such as essential oils (EOs), resulting in adverse effects to the mother and fetus. Our objective was to evaluate and compare the potential endocrine disrupting effects of chlorpyrifos "free" or in contaminated lavender EO. We studied the release of four hormones and the activation of the P2X7 cell death receptor in human placental JEG-Tox cells as key biomarkers of endocrine toxicity for pregnant women (hPlacentox assay). We observed that "free" chlorpyrifos disrupted placental hormones and activated the P2X7 receptor, whereas chlorpyrifos in lavender EO disrupted only the placental hormones. We confirm that chlorpyrifos can be classified as an endocrine disrupting chemical (EDC) for pregnant women and point out that its endocrine disrupting effect may not be apparent when present in lavender EOs. Our results reveal the existence of specific reverse cocktail effects that may have protective properties against EDCs.

Endocrine disrupting chemicals in the environment: Environmental sources, biological effects, remediation techniques, and perspective

Endocrine disrupting chemicals (EDCs) have been identified as emerging contaminants, which poses a great threat to human health and ecosystem. Pesticides, polycyclic aromatic hydrocarbons, dioxins, brominated flame retardants, steroid hormones and alkylphenols are representative of this type of contaminant, which are closely related to daily life. Unfortunately, many wastewater treatment plants (WWTPs) do not treat EDCs as targets in the normal treatment process, resulting in EDCs entering the environment. Few studies have systematically reviewed the related content of EDCs in terms of occurrence, harm and remediation. For this reason, in this article, the sources and exposure routes of common EDCs are systematically described. The existence of EDCs in the environment is mainly related to human activities (Wastewater discharges and industrial activities). The common hazards of these EDCs are clarified based on available toxicological data. At the same time, the mechanism and effect of some mainstream EDCs remediation technologies (such as adsorption, advanced oxidation, membrane bioreactor, constructed wetland, etc.) are separately mentioned. Moreover, our perspectives are provided for further research of EDCs.

Chlorpyrifos Occurrence and Toxicological Risk Assessment: A Review

Chlorpyrifos (CPF) was the most frequently used pesticide in food production in the European Union (EU) until 2020. Unfortunately, this compound is still being applied in other parts of the world. National monitoring of pesticides conducted in various countries indicates the presence of CPF in soil, food, and water, which may have toxic effects on consumers, farmers, and animal health. In addition, CPF may influence changes in the population of fungi, bacteria, and actinomycete in soil and can inhibit nitrogen mineralization. The mechanisms of CPF activity are based on the inhibition of acetylcholinesterase (AChE) activity. This compound also exhibits reproductive toxicity, neurotoxicity, and genotoxicity. The problem seems to be the discrepancy between the actual observations and the final conclusions drawn for the substance's approval in reports presenting the toxic impact of CPF on human health. Therefore, this influence is still a current and important issue that requires continuous monitoring despite its withdrawal from the market in the EU. This review traces the scientific reports describing the effects of CPF resulting in changes occurring in both the environment and at the cellular and tissue level in humans and animals. It also provides an insight into the hazards and risks to human health in food consumer products in which CPF has been detected.

Hormonal profile changes induced by pesticide mixture exposure in female rats revealed by hair analysis

Pesticide exposure has been associated with hormonal disruption in both animals and humans. However, there is limited knowledge of the combined effects of complex mixtures of pesticides on endogenous hormone levels. Here, we used hair analysis to assess the impact of a pesticide mixture comprising 19 components from multiple chemical classes at eight doses of 0-400 μg/kg body weight (bw) three times per week per component on concentrations of 36 steroid and thyroid hormones in female rats over a 90-day exposure period. We detected 13 hormones in rat hair, namely estradiol (E2), androstenedione (AD), testosterone (T), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), pregnenolone (P5), progesterone (P4), 11-deoxycorticosterone (11-DOC), corticosterone (CORT), 3,3'-l-diiodothyronine (T2), 3,5,3'-l-triiodothyronine (T3), 3,3',5'-l-triiodothyronine (rT3), and 3,5,3',5'-l-tetraiodothyronine (T4). In comparison to the control group, hair E2 concentration was significantly lower in the two highest (200 and 400 μg/kg bw) exposure groups, whereas hair DHEAS and CORT concentrations were significantly higher in the 40 μg/kg bw and the highest exposure groups, respectively. Results from generalized additive models suggest that pesticide exposure resulted in monotonic dose responses in hair E2 concentration, CORT concentration and DHEA/CORT molar ratio but nonmonotonic dose responses in hair T concentration, DHEAS concentration, P4/P5 and DHEA/DHEAS molar ratios. The associations of E2, CORT and DHEA/CORT ratio with exposure intensity were confirmed by their significant linear relationships with hair concentrations of at least 23 of the 25 exposure biomarkers analyzed. Our results demonstrate that exposure to low levels of the pesticide mixture evaluated here can alter hair reproductive and adrenal hormones levels.

Thyroid Cancer and Pesticide Use in a Central California Agricultural Area: A Case Control Study

OBJECTIVE

To examine environmental factors that influence risk of thyroid cancer.

METHODS

We performed a case-control study utilizing thyroid cancer cases from the California Cancer Registry (1999-2012) and controls sampled in a population-based manner. Study participants were included if they were diagnosed with thyroid cancer, lived in the study area at their time of diagnosis, and were ≥35 years of age. Controls were recruited from the same area and eligible to participate if they were ≥35 years of age and had been living in California for at least 5 years prior to the interview. We examined residential exposure to 29 agricultural use pesticides, known to cause DNA damage in vitro or are known endocrine disruptors. We employed a validated geographic information system-based system to generate exposure estimates for each participant.

RESULTS

Our sample included 2067 cases and 1003 controls. In single pollutant models and within a 20-year exposure period, 10 out of 29 selected pesticides were associated with thyroid cancer, including several of the most applied pesticides in the United States such as paraquat dichloride [odds ratio (OR): 1.46 (95% CI: 1.23, 1.73)], glyphosate [OR: 1.33 (95% CI: 1.12, 1.58)], and oxyfluorfen [OR: 1.21 (95% CI: 1.02, 1.43)]. Risk of thyroid cancer increased proportionately to the total number of pesticides subjects were exposed to 20 years before diagnosis or interview. In all models, paraquat dichloride was associated with thyroid cancer.

CONCLUSIONS

Our study provides first evidence in support of the hypothesis that residential pesticide exposure from agricultural applications is associated with an increased risk of thyroid cancer.

Association of urinary metabolites of non-persistent pesticides with serum sex hormones among the US females: NHANES 2013-2014

BACKGROUND

Evidence indicated the possibility of non-persistent pesticides disrupting the homeostasis of sex hormones. However, few studies have focused on this relationship in females. We aimed to explore the relationship between non-persistent pesticide exposure and sex hormones among the US females from the National Health and Nutrition Examination Survey 2013-2014.

METHODS

A total of 790 females, including girls (6-11 years), female adolescents (12-19 years), and adult females (>19 years), were enrolled in this study. Age stratified associations of individual non-persistent pesticide metabolites and their mixtures with sex hormones were analyzed by weighted multiple linear regression and Bayesian kernel machine regression (BKMR) using spot urinary non-persistent pesticide measurement, including 2,4-dichlorophenoxyacetic acid (2,4-D), 3,5,6-trichloropyridinol (TCPY), para-nitrophenol (PNP) and 3-phenoxybenzoic acid (3-PBA), and three serum sex hormones [total testosterone (TT), estradiol (E2) and sex hormone binding globulin (SHBG)].

RESULTS

In girls, weighted multivariate linear regression indicated that both 2,4-D and PNP were negatively associated with TT, and TCPY was inversely associated with SHBG. In female adolescents, TCPY was negatively associated with TT and E2, and 3-PBA was negatively associated with SHBG; positive associations were detected both in 2,4-D with SHBG, and in PNP with TT. In adult females, a higher concentration of 3-PBA was associated with higher levels of TT. The BKMR model showed that in female adolescents, the concentrations of pesticide metabolite mixtures at or above the 55th percentile were negatively related to the levels of E2 compared with their mixtures at 50th percentile, and an inverse U-shaped exposure-response function between PNP and E2 was found.

CONCLUSIONS

Associations between the four non-persistent pesticide metabolites and serum sex hormones were identified in the US females from NHANES 2013-2014 and these associations were age dependent, especially in adolescents. Large-scale cohort studies are needed to confirm these findings and elucidate the potential biological mechanisms.

Pre- and Postnatal Dietary Exposure to a Pesticide Cocktail Disrupts Ovarian Functions in 8-Week-Old Female Mice

Female infertility has a multifactorial origin, and exposure to contaminants, including pesticides, with endocrine-disrupting properties is considered to be involved in this reproductive disorder, especially when it occurs during early life. Pesticides are present in various facets of the environment, and consumers are exposed to a combination of multiple pesticide residues through food intake. The consequences of such exposure with respect to female fertility are not well known. Therefore, we aimed to assess the impact of pre- and postnatal dietary exposure to a pesticide mixture on folliculogenesis, a crucial process in female reproduction. Mice were exposed to the acceptable daily intake levels of six pesticides in a mixture (boscalid, captan, chlorpyrifos, thiacloprid, thiophanate and ziram) from foetal development until 8 weeks old. Female offspring presented with decreased body weight at weaning, which was maintained at 8 weeks old. This was accompanied by an abnormal ovarian ultrastructure, a drastic decrease in the number of corpora lutea and progesterone levels and an increase in ovary cell proliferation. In conclusion, this study shows that this pesticide mixture that can be commonly found in fruits in Europe, causing endocrine disruption in female mice with pre- and postnatal exposure by disturbing folliculogenesis, mainly in the luteinisation process.

Temephos, an organophosphate larvicide for residential use: a review of its toxicity

Temephos (O,O,O',O'-tetramethyl O,O'-thiodi-p-phenylene bis(phosphorothioate)) is a larvicide belonging to the family of organophosphate pesticides used for the control of different vectors of diseases, such as dengue, Zika, chikungunya, and dracunculiasis. The aim of this review was to discuss the available published information about temephos toxicokinetics and toxicity in mammals. Temephos is quickly absorbed in the gastrointestinal tract, distributed to all organs, and then it accumulates mainly in adipose tissue. It is metabolized by S-oxidation, oxidative desulfuration, and hydrolysis reactions, with the possible participation of cytochrome P450 (CYP). Temephos is mainly eliminated by feces, whereas some of its metabolites are eliminated by urine. The World Health Organization classifies it as class III: slightly dangerous with a NOAEL (no-observed adverse effect level) of 2.3 mg/kg/day for up to 90 days in rats, based on brain acetylcholinesterase (AChE) inhibition. A LOAEL (lowest observable adverse effect level) of 100 mg/kg/day for up to 44 days in rats was proposed based on cholinergic symptoms. However, some studies have shown that temephos causes toxic effects in mammals. The inhibition of the enzyme acetylcholinesterase (AChE) is one of its main demonstrated effects; however, this larvicide has also shown genotoxic effects and some adverse effects on male reproduction and fertility, as well as liver damage, even at low doses. We performed an extensive review through several databases of the literature about temephos toxicokinetics, and we recommend to revisit current assessment of temephos with the new available data.

Lupeol inhibits pesticides induced hepatotoxicity via reducing oxidative stress and inflammatory markers in the rats

The present study was aimed at investigating the toxicity of various pesticides on rat liver. It also aimed to show whether this toxicity could be avoided using lupeol. Adult male Wistars albino rats were randomly divided into nine groups. Control groups were given saline, corn oil, and lupeol; pesticide groups were given malathion, chlorpyrifos, and tebuconazole; in the other three treatments, same doses of pesticides and lupeol were given to the rats for ten days. Histopathological examination showed severe degenerative changes in the pesticide groups. Serum AChE activities, liver GSH, total antioxidant capacity levels, AChE, CAT, SOD, GPx, GR, Na⁺/K⁺-ATPase, ARE, and PON were decreased, while serum TNF-α, liver LPO, HP, NO, AOPP, total oxidant status, ROS, and oxidative stress index levels as well as AST, ALT, ALP, GST, arginase and xanthine oxidase activities were increased in the pesticides administered groups. It was observed that the PCNA levels determined by the immunohistochemical method increased in the pesticide groups. Also, the results Raman spectroscopy suggest that the technique may be used to understand/have an insight into pesticide toxicity mechanisms. The administration of lupeol demonstrated a hepatoprotective effect against pesticide-induced toxicity.

Comparison of the Toxicological Effects of Pesticides in Non-Tumorigenic MCF-12A and Tumorigenic MCF-7 Human Breast Cells

Humans are exposed to residues of organophosphate and neonicotinoid pesticides, commonly used in agriculture. Children are particularly vulnerable and, among possible adverse outcomes, the increased incidence of premature mammary gland development (thelarche) has raised concern. We evaluated the toxicological effects of chlorpyrifos (CPF), imidacloprid (IMI) and glyphosate (GLY) at exposure concentrations occurring in children on the tumorigenic MCF-7 and non-tumorigenic MCF-12A breast cell lines, as representative of the target organ model, assessing cytotoxicity, apoptosis, necrosis, intracellular reactive oxygen species (ROS) and ATP levels, 17β-estradiol secretion and gene expression of nuclear receptors involved in mammary gland development. The pesticides decreased cell vitality in MCF-7 and cell proliferation in MCF-12A cells. ATP levels were decreased in MCF-7 cells by pesticides and apoptosis was increased in MCF-12A cells only by GLY (2.3 nM). ROS production was decreased by pesticides in both cell lines, except IMI (1.6 nM) in MCF-7 cells. Endocrine disrupting activity was highlighted by induction of 17β-estradiol secretion and modulation of the gene expression of estrogen alpha and beta, progesterone, androgen, and aryl hydrocarbon receptors in both cell lines. The use of MCF-7 and MCF-12A cells highlighted dissimilar modes of action of each pesticide at low human relevant concentrations.

Chimpanzee exposure to pollution revealed by human biomonitoring approaches

Wildlife is increasingly exposed to environmental pollution, but data illustrating to what extent this exposure can impact health and survival of endangered species is missing. In humans, hair matrix analysis is a reliable tool for assessing cumulative exposure to organic pollutants such as pesticides but has rarely been used in other primates for this purpose. LC/MS-MS and GC/MS-MS multi-residue methods were used to screen the presence of 152 organic pollutants and their metabolites belonging to 21 different chemical families in hair samples from our closest relative, the chimpanzee. Samples were collected from 20 wild chimpanzees in Sebitoli, Kibale National Park, Uganda and 9 captive chimpanzees in the Réserve Africaine de Sigean, France. In total, 90 chemicals were detected, 60 in wild chimpanzees and 79 in captive chimpanzees. The median concentrations of detected chemicals in captive individuals were significantly higher than those in wild chimpanzees. Hair from the captive individuals at RAS was sampled a second time after 6 months in an environment of reduced exposure to these pollutants (diet of organic food, decreased use of plastic food and water containers). The number of chemicals detected in captive chimpanzees reduced from 79 to 63, and their concentrations were also significantly reduced. In the present study we report for the first time the use of hair analysis to detect organic pollutants in primate hair. We conclude that both wild and captive chimpanzees are exposed to a large range of different chemicals through their diet. Our study provides surprising and alarming evidence that besides the direct threats of poaching, deforestation and diseases, wild chimpanzees might be endangered by indirect consequences of anthropic activities. As chimpanzees are our closest relatives, our results should be considered as an alert for human health as well.

Endocrine disruptor chlorpyrifos promotes migration, invasion, and stemness phenotype in 3D cultures of breast cancer cells and induces a wide range of pathways involved in cancer progression

Organophosphorus chlorpyrifos (CPF) is currently considered an endocrine disruptor (ED), as it can imitate hormone actions both in vitro and in vivo. We recently reported that CPF induces migration and invasion in 2D cultures and changes the expression of key molecular markers involved in epithelial mesenchymal transition in MCF-7 and MDA-MB-231 cell lines. In this study, we investigated whether CPF could behave as a predisposing factor for tumors to become more metastatic and aggressive using 3D culture models. In MCF-7 cells, 0.05 μM CPF induced an increase in the number and size of mammospheres via estrogen receptor alpha (ERα) and c-SRC. Furthermore, 0.05 μM CPF increased the area of spheroids generated from MCF-7 cells, induced invasion using both Matrigel® and type 1 collagen matrices, and increased cell migration capacity via ERα in this 3D model. In turn, 50 μM CPF increased cell migration capacity and invasion using type 1 collagen matrix. In monolayers, CPF increased the phosphorylation and membrane translocation of c-SRC at both concentrations assayed. CPF at 0.05 μM boosted p-AKT, p-GSK-3β and p-P38. While p-AKT rose in a ERα-dependent way, p-GSK-3β was dependent on ERα- and c-SRC, and p-P38 was only dependent on c-SRC. On the other hand, the increase in p-AKT and p-P38 induced by 50 μM CPF was dependent on the c-SRC pathway. We also observed that 0.05 μM CPF increased IGF-1R and IRS-1 expression and that 50 μM CPF induced IGF-1Rβ phosphorylation. In the MDA-MB-231 cell line, 0.05 and 50 μM CPF increased p-c-SRC. Finally, p-AKT and p-GSK-3β were also induced by CPF at 0.05 and 50 μM, and an increase in p-P38 was observed at 50 μM. Taken together, these data provide support for the notion that CPF may represent a risk factor for breast cancer development and progression.

Using Transcriptomics and Metabolomics to Understand Species Differences in Sensitivity to Chlorpyrifos in Japanese Quail and Double-Crested Cormorant Embryos

Modern 21st-century toxicity testing makes use of omics technologies to address critical questions in toxicology and chemical management. Of interest are questions relating to chemical mechanisms of toxicity, differences in species sensitivity, and translation of molecular effects to observable apical endpoints. Our study addressed these questions by comparing apical outcomes and multiple omics responses in early-life stage exposure studies with Japanese quail (Coturnix japonica) and double-crested cormorant (Phalacrocorax auritus), representing a model and ecological species, respectively. Specifically, we investigated the dose-dependent response of apical outcomes as well as transcriptomics and metabolomics in the liver of each species exposed to chlorpyrifos, a widely used organophosphate pesticide. Our results revealed a clear pattern of dose-dependent disruption of gene expression and metabolic profiles in Japanese quail but not double-crested cormorant at similar chlorpyrifos exposure concentrations. The difference in sensitivity between species was likely due to higher metabolic transformation of chlorpyrifos in Japanese quail compared to double-crested cormorant. The most impacted biological pathways after chlorpyrifos exposure in Japanese quail included hepatic metabolism, oxidative stress, endocrine disruption (steroid and nonsteroid hormones), and metabolic disease (lipid and fatty acid metabolism). Importantly, we show consistent responses across biological scales, suggesting that significant disruption at the level of gene expression and metabolite profiles leads to observable apical responses at the organism level. Our study demonstrates the utility of evaluating effects at multiple biological levels of organization to understand how modern toxicity testing relates to outcomes of regulatory relevance, while also highlighting important, yet poorly understood, species differences in sensitivity to chemical exposure. Environ Toxicol Chem 2021;40:3019-3033. © 2021 SETAC.

Aryl Hydrocarbon Receptor Activation Produces Heat Shock Protein 90 and 70 Overexpression, Prostaglandin E2/Wnt/β-Catenin Signaling Disruption, and Cell Proliferation in MCF-7 and MDA-MB-231 Cells after 24 h and 14 Days of Chlorpyrifos Treatment

The biocide chlorpyrifos (CPF) was described to increase breast cancer risk in humans, to produce breast cancer in animals, and to induce cell proliferation in MCF-7 and MDA-MB-231 cells after 1 and 14 days of treatment. The entire mechanisms related to these CPF actions remain unknown. CPF induced cell proliferation in MCF-7 and MDA-MB-231 cells after 1 and 14 days of treatment by AhR activation through the PGE2/Wnt/β-catenin pathway and HSP90 and HSP70 overexpression. Our results reveal new information on CPF toxic mechanisms induced in human breast cancer cell lines, which could assist in elucidating its involvement in breast cancer.

Chronic exposure to low concentrations of chlorpyrifos affects normal cyclicity and histology of the uterus in female rats

Chlorpyrifos (CPF), the most used insecticide in Argentina, can act as an endocrine disruptor at low doses. We previously demonstrated that chronic exposure to CPF induces hormonal imbalance in vivo. The aim of this work was to study the effects of low concentrations of CPF (0.01 and 1 mg/kg/day) on the reproductive system of virgin adult rats. In the ovary, we studied the effects of CPF on steroidogenesis by determining steroid hormone content by RIA and CYP11 and CYP19 enzyme expression by qRT-PCR. The estrous cycle was evaluated by microscopic observation of vaginal smear, as well as by changes in uterine histology. In endometrium, we determined the fractal dimension and expression of PCNA, ERα and PR by IHC. Our results showed that chronic exposure to CPF affects ovarian steroid synthesis, causing alterations in the normal cyclicity of animals. In addition, CPF induced proliferative changes in the uterus, suggesting that it could affect reproduction or act as a risk factor in the development of uterine proliferative pathologies.

Cumulative exposure characteristics of vegetable farmers exposed to Chlorpyrifos in Central Java - Indonesia; a cross-sectional study

Background

Agriculture is a major economic sector in Indonesia. Chemical pesticides are widely being used in agriculture for controlling pest. There is a growing concern that pesticide exposure, particularly chlorpyrifos (CPF) exposure, combined with other occupational characteristics that determine the level of exposure, can lead to further health impacts for farmers. Our objective was to evaluate the cumulative exposure characteristics among farmers exposed to CPF by using a validated algorithm.

Methods

We conducted a cross-sectional study of 152 vegetable farmers aged 18–65 who actively used CPF for at least 1 year in Central Java, Indonesia. Subject characteristics were obtained using a structured interviewer-administered questionnaire, addressed for sociodemographic and work-related characteristics. The cumulative exposure level (CEL) was estimated as a function of the intensity level of pesticide exposure (IL), lifetime years of pesticide use and the number of days spraying per year. CEL was subsequently classified into two groups, high and low exposure groups. The difference in characteristics of the study population was measured using Chi-square, independent-t or Mann-Whitney test. Association between CEL and its characteristics variables were performed by multiple linear regression.

Results

Seventy-one subjects (46.7%) were classified as the high exposure group. The use of multiple pesticide mixtures was common among our study population, with 94% of them using 2 or more pesticides. 73% reported direct contact with concentrated pesticides product, and over 80% reported being splashed or spilt during preparation or spraying activity. However, we found that the proportion of proper personal protective equipment (PPE) use in our subjects was low. Higher volume of mixture applied (p <  0.001) and broader acres of land (p = 0.001) were associated with higher cumulative exposure level, while using long-sleeved clothes and long pants (p <  0.05) during pesticide spraying were associated with lower cumulative exposure after adjusted for age and gender.

Conclusions

These findings indicate an inadequate knowledge of using pesticides properly. Thus, we recommend comprehensive training on pesticide usage and encourage proper PPE to reduce the exposure level.

Organophosphate pesticide exposure, hormone levels, and interaction with PON1 polymorphisms in male adolescents

OBJECTIVE

To examine the association between urinary metabolites of organophosphate (OP) pesticides and serum concentrations of thyroid and reproductive hormones in male adolescents and to assess the potential effect of interactions between OP pesticides and paraoxonase 1 (PON1) polymorphisms on hormone levels.

METHODS

Study subjects (N = 117) were male 16- to 17-year-olds from the Environment and Childhood (INMA)-Granada cohort in Spain. Concentrations of 3,5,6-trichloro-2-pyridinol (TCPy), a metabolite of chlorpyrifos/chlorpyrifos-methyl, 2-isopropyl-6-methyl-4-pyrimidinol (IMPy), a metabolite of diazinon, and diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP), non-specific metabolites of OP pesticides, were measured in a spot urine sample from each subject and adjusted for creatinine. Levels of reproductive hormones (total testosterone [TT], estradiol [E₂], dehydroepiandrosterone sulfate [DHEAS], sex hormone binding globulin [SHBG], luteinizing hormone [LH], follicle stimulating hormone [FSH], anti-Müllerian hormone [AMH], insulin growth factor 1 [IGF-1], and prolactin), thyroid hormones (free thyroxine [FT4], total triiodothyronine [TT3], and thyroid stimulating hormone [TSH]), and PON1 Q192R and L55M polymorphisms were determined in blood drawn during the same clinical visit.

RESULTS

Multiple linear regression models showed that detectable levels of TCPy were associated with an increase in DHEAS and decreases in E₂, FSH, and AMH; detectable IMPy with increases in E₂, DHEAS, FSH, AMH, and prolactin and decreases in SHBG and LH; and detectable DETP with marginally-significant increases in TT and TT3 and decreases in FSH, AMH, and prolactin. The effect of IMPy and DETP on DHEAS and TT levels, respectively, was higher in subjects that carried the PON1 55MM genotype, while the effect of TCPy, IMPy, and DETP on thyroid hormone levels was higher in PON1 192QR/RR or 55MM genotype carriers.

CONCLUSIONS

In male adolescents, non-occupational exposure to OP pesticides was associated with several changes in reproductive and thyroid hormone levels, and the magnitude of some associations was greater in adolescents genetically more susceptible to OP pesticide exposure who carry the PON1 55MM genotype.

Chlorpyrifos induces cell proliferation in MCF-7 and MDA-MB-231 cells, through cholinergic and Wnt/β-catenin signaling disruption, AChE-R upregulation and oxidative stress generation after single and repeated treatment

Chlorpyrifos (CPF) biocide, is associated with breast cancer. The processes underlying this association have not been elucidated to date. CPF increases MCF-7 and MDA-MB-231 cell proliferation after acute and long-term treatment, partially through KIAA1363 overexpression and aryl-hydrocarbon receptor activation but also through estrogen receptor-alpha activation after 24 h exposure in MCF-7 cells, suggesting other mechanisms may be involved. CPF induces reactive oxygen species (ROS) generation, acetylcholine accumulation, and overexpression of acetylcholinesterase-R/S (AChE-R/S) variants, while it also alters the Wnt/β-catenin pathway, both in vitro and in vivo, in processes different from cancer. These latter mechanisms are also linked to cell proliferation and could mediate this effect induced by CPF. Our results show that CPF (0.01-100 μM), following one-day and fourteen-days treatment, respectively, induced ROS generation and lipid peroxidation, and acetylcholine accumulation due to AChE inhibition, Wnt/β-catenin up- or downregulation depending on the CPF treatment concentration, and AChE-R and AChE-S overexpression, with the latter being mediated through GSK-3β activity alteration. Finally, CPF promoted cell division through ACh and ROS accumulation, AChE-R overexpression, and Wnt/β-catenin signaling disruption. Our results provide novel information on the effect of CPF on human breast cancer cell lines that may help to explain its involvement in breast cancer.

ENDOCRINE DISTURBANCES INDUCED BY LOW-DOSE ORGANOPHOSPHATE EXPOSURE IN MALE WISTAR RATS

BACKGROUND

Organophosphate exposure induces many endocrine effects.

AIM

In this study we observed the effects of acute stress induced by cholinesterase inhibition on the main hormonal axes.

MATERIALS AND METHODS

We included thirteen weanling Wistar rats that were subjected to organophosphate exposure. They were first tested for baseline levels of butyrylcholinesterase, cortisol, free triiodothyronine, thyroxine, thyroid-stimulating hormone and prolactin. Secondly, chlorpyrifos was administered. Next samples were taken to determine the level of all the above-mentioned parameters.

RESULTS

Butyrylcholinesterase was significantly decreased after exposure (p<0.001). Cortisol levels were significantly higher after clorpyrifos administration (358.75±43 vs. 241.2±35 nmoL/L)(p<0.01). Although prolactin had a growing trend (450.25±24.65 vs. 423±43.4 uI/mL), the results were not statistically significant. Both free triiodothyronine and thyroxine were significantly higher after exposure. Surprisingly, thyroid-stimulating hormone level almost doubled after exposure with high statistical significance (p<0.001), suggesting a central stimulation of thyroid axis. Butyrylcholinesterase level was proportional with thyroid-stimulating hormone level (p=0.02) and thyroxine level was inversely correlated to the cortisol level (p=0.01). Acute cholinesterase inhibition may induce high levels of cortisol, free triiodothyronine, thyroxine and thyroid-stimulating hormone. From our knowledge this is the first study dedicated to the assessment of acute changes of hormonal status in weanling animals after low-dose organophosphate exposure.Conclusion. Acute cholinesterase inhibition may cause acute phase hormonal disturbances specific to shocked patients.

Evaluation of Gonadal Alterations in a Population Environmentally Exposed to a Mixture of Endocrine Active Pesticides

Although there are studies that show that some pesticides produce gonadal dysfunction and gonadal cancer in different animals, there are not many studiesregardinghumans. This study determined the prevalence and risk in humans of developing ovarian or testicular dysfunction or cancer in areas with distinct exposure to pesticides, which have endocrine disrupting properties. A population-based case-control study was carried out on humans living in ten health districts of Andalusia (Southern Spain) classified as areas of high or low environmental exposure to pesticides according to agronomic criteria. The study population included 5332 cases and 13,606 controls. Data were collected from computerized hospital records between 2000 and 2018.The risk of gonadal dysfunction or cancer was significantly higher in areas with higher use of pesticides in relation to those with lower use.

A comprehensive review on chlorpyrifos toxicity with special reference to endocrine disruption: Evidence of mechanisms, exposures and mitigation strategies

Chlorpyrifos (CPF) is a broad-spectrum chlorinated organophosphate (OP) pesticide used for the control of a variety of insects and pathogens in crops, fruits, vegetables, as well as households, and various other locations. The toxicity of CPF has been associated with neurological dysfunctions, endocrine disruption, and cardiovascular diseases (CVDs). It can also induce developmental and behavioral anomalies, hematological malignancies, genotoxicity, histopathological aberrations, immunotoxicity, and oxidative stress as evidenced by animal modeling. Moreover, eye irritation and dermatological defects are also reported due to CPF toxicity. The mechanism of action of CPF involves blocking the active sites of the enzyme, acetylcholinesterase (AChE), thereby producing adverse nervous system effects. Although CPF has low persistence in the body, its active metabolites, 3,5,6-trichloro-2-pyridinol (TCP), and chlorpyrifos-oxon (CPO) are comparatively more persistent, albeit equally toxic, and thus produce serious health complications. The present review has been compiled taking into account the work related to CPF toxicity and provides a brief compilation of CPF-induced defects in animals and humans, emphasizing the abnormalities leading to endocrine disruption, neurotoxicity, reproductive carcinogenesis, and disruptive mammary gland functionality. Moreover, the clinical signs and symptoms associated with the CPF exposure along with the possible pharmacological treatment are reported in this treatise. Additionally, the effect of food processing methods in reducing CPF residues from different agricultural commodities and dietary interventions to curtail the toxicity of CPF has also been discussed.

Cytotoxic and estrogenic activity of chlorpyrifos and its metabolite 3,5,6-trichloro-2-pyridinol. Study of marine yeasts as potential toxicity indicators

Chlorpyrifos (CP) is one of the organophosphate insecticides most used worldwide today. Although the main target organ for CP is the nervous system triggering predominantly neurotoxic effects, it has suggested other mechanisms of action as cytotoxicity and endocrine disruption. The risk posed by the pesticide metabolites on non-target organisms is increasingly recognized by regulatory agencies and natural resource managers. In the present study, cytotoxicity and estrogenic activity of CP, and its principal metabolite 3,5,6-trichloro-2-pyridinol (TCP) have been evaluated by in vitro assays, using two mammalian cell lines (HEK293 and N2a), and a recombinant yeast. Results indicate that TCP is more toxic than CP for the two cell lines assayed, being N2a cells more sensitive to both compounds. Both compounds show a similar estrogenic activity being between 2500 and 3000 times less estrogenic than 17β-estradiol. In order to find new toxicity measurement models, yeasts isolated from marine sediments containing CP residues have been tested against CP and TCP by cell viability assay. Of the 12 yeast strains tested, 6 of them showed certain sensitivity, and a concentration-dependent response to the tested compounds, so they could be considered as future models for toxicity tests, although further investigations and proves are necessary.

Chlorpyrifos subthreshold exposure induces epithelial-mesenchymal transition in breast cancer cells

Chlorpyrifos (CPF) is one of the most frequently used pesticide in extensive agriculture around the world and can be incorporated by humans and animals with possible consequences on health. The effects of this pesticide on carcinogenesis are not clear and there is no consensus concerning the risks of this compound. In previous work, we demonstrated that CPF induces proliferation of breast cancer cells both in vivo and in vitro. In this work we investigate whether CPF promotes the epithelial-mesenchymal transition (EMT) in breast cancer cells. Herein, we demonstrate that 50 μM CFP induces invasion in MCF-7 and MDA-MB-231 cells. In addition, 0.05 and 50 μM CPF increases migration in both cell lines. In MCF-7 cells, 0.05 and 50 μM CPF increase the metalloprotease MMP2 expression and decrease E-Cadherin and β-Catenin expression diminishing their membrane location. Furthermore, 50 μM CPF induces Vimentin expression and Slug nuclear translocation in MCF-7 cells. 0.05 and 50 μM CPF increase MMP2 gelatinolytic activity and expression, decrease β-Catenin expression and increase Vimentin expression in MDA-MB-231 cells. Inhibition of the oncoprotein c-Src reverses all the effects induced by CPF in MDA-MB-231 but not in MCF-7 indicating that c-Src is a kinase with a crucial role in the cells which grow in an estrogen-independent way. In MCF-7 cells both c-Src and estrogen receptor alpha must be blocked to completly inhibit the CPF-mediated effects. Our results show for the first time that the exposure to subthreshold concentrations of CPF promotes the modulation of EMT-molecular markers and pathways. These results, together with the ubiquitous distribution of the pesticide CPF, make it of utmost importance to take measures to minimize the risk of exposure to this compound.

In vitro profiling of the potential endocrine disrupting activities affecting steroid and aryl hydrocarbon receptors of compounds and mixtures prevalent in human drinking water resources

Prioritizing chemicals posing threats to drinking water resources is crucial for legislation considering the cost of water treatment, remediation, and monitoring. We profiled in vitro potential endocrine disrupting activities (both agonistic and antagonistic) of 18 contaminants most prevalent in Walloon raw water resources intended for drinking water production, including several compound groups: pesticides, perfluorinated compounds, polycyclic aromatic hydrocarbons, a corrosion inhibitor, and bisphenol A. Mixtures thereof relevant for human realistic exposure were also investigated. Seven luciferase reporter gene cell lines were used i.e. three (human and rat) responsive to dioxins through the aryl hydrocarbon receptor (AhR) and four (human) responsive to steroids through the estrogen (ER), androgen (AR), progesterone (PR), and glucocorticoid (GR) receptors. Among the 18 compounds, ten caused at least one response in at least one receptor. Specifically, chlorpyrifos, bisphenol A, fluoranthene, phenanthrene, and benzo [a]pyrene displayed significant activities on several receptors. Bisphenol A agonized ER, but abolished the cells' response to androgen and progesterone. While fluoranthene and phenanthrene strongly reduced human AhR and AR transactivation, benzo [a]pyrene strongly activated AhR and ER, but inhibited GR and AR. In human breast cancer cells, benzo [a]pyrene dramatically activated AhR, inducing a 10-fold higher response than 2,3,7,8-tetrachlorodibenzodioxin (TCDD) at concentrations possibly found realistically in human blood. The mixture of the 18 compounds exerted both ER and rat AhR agonism, with the main contribution being from benzo [a]pyrene or its combination with bisphenol A. Moreover, the mixture significantly inhibited TCDD-induced CYP1A activity (detected only by EROD assays) in human hepatoma cells.

Acute toxicity of chlorpyrifos and its metabolite 3,5,6-trichloro-2-pyridinol alone and in combination using a battery of bioassays

Acute toxicity of chlorpyrifos (CP) and its principal metabolite 3,5,6-trichloro-2-pyridinol (TCP) alone and in combination have been evaluated using a test battery comprising aquatic organisms from different trophic levels: luminescent marine bacteria Aliivibrio fischeri, freshwater unicellular alga Pseudokirchneriella subcapitata, and cladoceran Daphnia magna. As expected, D. magna was the more sensitive organism to the compounds tested, being CP more toxic than its metabolite. On the contrary, TCP was found to be more toxic than its parental compound to A. fischeri and P. subcapitata. In all cases, the mixture of CP and its metabolite was more toxic than the compounds tested separately, multiplying between 5 and 200 times CP toxicity level and up to 15 times TCP toxicity level. These results indicate that the co-existence of parent chemical and its degradation product in the environment can result in a synergic interaction involving high risk to the aquatic ecosystems. Graphical abstract.

Angiogenesis signaling in breast cancer models is induced by hexachlorobenzene and chlorpyrifos, pesticide ligands of the aryl hydrocarbon receptor

Breast cancer incidence is increasing globally and pesticides exposure may impact risk of developing this disease. Hexachlorobenzene (HCB) and chlorpyrifos (CPF) act as endocrine disruptors, inducing proliferation in breast cancer cells. Vascular endothelial growth factor-A (VEGF-A), cyclooxygenase-2 (COX-2) and nitric oxide (NO) are associated with angiogenesis. Our aim was to evaluate HCB and CPF action, both weak aryl hydrocarbon receptor (AhR) ligands, on angiogenesis in breast cancer models. We used: (1) in vivo xenograft model with MCF-7 cells, (2) in vitro breast cancer model with MCF-7, and (3) in vitro neovasculogenesis model with endothelial cells exposed to conditioned medium from MCF-7. Results show that HCB (3 mg/kg) and CPF (0.1 mg/kg) stimulated vascular density in the in vivo model. HCB and CPF low doses enhanced VEGF-A and COX-2 expression, accompanied by increased levels of nitric oxide synthases (NOS), and NO release in MCF-7. HCB and CPF high doses intensified VEGF-A and COX-2 levels but rendered different effects on NOS, however, both pesticides reduced NO production. Moreover, our data indicate that HCB and CPF-induced VEGF-A expression is mediated by estrogen receptor and NO, while the increase in COX-2 is through AhR and NO pathways in MCF-7. In conclusion, we demonstrate that HCB and CPF environmental concentrations stimulate angiogenic switch in vivo. Besides, pesticides induce VEGF-A and COX-2 expression, as well as NO production in MCF-7, promoting tubulogenesis in endothelial cells. These findings show that pesticide exposure could stimulate angiogenesis, a process that has been demonstrated to contribute to breast cancer progression.

Chlorpyrifos effects on integrin alpha v and beta 3 in implantation window phase

Chlorpyrifos (CPF), as a worldwide pesticide, can effect on the integrins αv and β3 which play a main role in the implantation window. Therefore, the aim of this study was to consider CPF effects on integrin alpha v and beta 3 in implantation window phase. Thirty female NMRI mice were separated into groups of CPF, sham, and control. After 6 weeks, each group was mated, and on the 5th day of gestation, all mice were euthanized. Estradiol and progesterone levels were detected by the enzyme-linked immunosorbent assay (ELISA) test; two subunits of integrins (αv and β3) genes and proteins of endometrium were analyzed by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry method, respectively. Fibrosis of the liver which evaluated by Masson's trichrome stain was increased in the CPF group compared with the others. But estradiol and progesterone levels were significantly decreased in CPF groups. Based on the findings, the proportion of genes' expressions of integrin subunits declined by the effect of CPF, while there was not any notable consequence on mice in the sham group. Alpha v and beta 3 integrin proteins expressed in all groups, but the concentration of these proteins in CPF groups was lower than in other groups. This study has shown that the decline of estradiol and progesterone downregulates the expression of αv and β3 integrins which were influenced by CPF exposure. Changing these patterns of proteins could have numerous influences on unsuccessful implantation. Therefore, this experimental study recommends that inclusive consideration of the effects of insecticides may be crucial to women's unrecognized cause of infertility.

Organophosphate Pesticide Exposure and Breast Cancer Risk: A Rapid Review of Human, Animal, and Cell-Based Studies

BACKGROUND

Organophosphate pesticides (OPs) are one of the most commonly used classes of insecticides in the U.S., and metabolites of OPs have been detected in the urine of >75% of the U.S.

POPULATION

While studies have shown that OP exposure is associated with risk of neurological diseases and some cancers, the relationship between OP exposure and breast cancer risk is not well understood.

METHODS

The aim of this rapid review was to systematically evaluate published literature on the relationship between OP exposure and breast cancer risk, including both epidemiologic and laboratory studies. Twenty-seven full-text articles were reviewed by searching on Pubmed, EMBASE, and Cochrane databases.

RESULTS

Some human studies showed that malathion, terbufos, and chlorpyrifos were positively associated with human breast cancer risk, and some laboratory studies demonstrated that malathion and chlorpyrifos have estrogenic potential and other cancer-promoting properties. However, the human studies were limited in number, mostly included agricultural settings in several geographical areas in the U.S., and did not address cumulative exposure.

CONCLUSIONS

Given the mixed results found in both human and laboratory studies, more research is needed to further examine the relationship between OP exposure and breast cancer risk, especially in humans in non-agricultural settings.

Chlorpyrifos-induced cell proliferation in human breast cancer cell lines differentially mediated by estrogen and aryl hydrocarbon receptors and KIAA1363 enzyme after 24 h and 14 days exposure

Organophosphate biocide chlorpyrifos (CPF) is involved with breast cancer. However, the mechanisms remain unknown. CPF increases cell division in MCF-7 cells, by estrogen receptor alpha (ERα) activation, although it is a weak ERα agonist, suggesting other mechanisms should be involved. Aromatic hydrocarbon receptor (AhR) activation increases cell division in human breast cancer cells, and CPF strongly activates it. Finally, the KIAA1363 enzyme, which is regulated by CPF, is overexpressed in cancer cells. Accordingly, we hypothesized that CPF or its metabolite chlorpyrifos-oxon (CPFO) could induce cell viability promotion in MCF-7 and MDA-MB-231 cell lines, through mechanisms related to ERα, AhR, and KIAA1363, after 24 h and 14 days treatment. Results show that, after acute and long-term treatment, CPF and CPFO alter differently KIAA1363, AhR, ER and cytochrome P450 isoenzyme 1A1 (CYP1A1) expression. In addition, they induced cell proliferation through ERα activation after 24 h exposure in MCF-7 cells and through KIAA1363 overexpression and AhR activation in MCF-7 and MDA-MB-231 cells after acute and long-term treatment. The results obtained in this work provide new information relative to the mechanisms involved in the CPF toxic effects that could lead to breast cancer disease.

Agrochemicals and neurogenesis

Agrochemicals or pesticides are compounds widely used to prevent, destroy or mitigate pests such as insects, rodents, herbs and weeds. However, most of them also act as environmental estrogens, anti-estrogens and/or antiandrogenic chemicals. In addition, both herbicides (such as glyphosate and paraquat) and insecticides (such as pyrethroids, organophosphates, neonicotinoids and rotenone) have been shown to exert significant adverse effects on hippocampal neurogenesis. These effects are particularly important because neurogenesis dysregulation could be associated with cognitive decline and neuropathologies such as Alzheimer's disease. This review focuses on the most commonly used agrochemicals in Argentina and their effects on the hippocampal neurogenesis of mammals. It also discusses the disruption of hormone synthesis and action as a possible mechanism through which these chemical compounds could alter the brain functions. Finally, we propose some lines of research to study the potential endocrine mechanisms involved in the effects of agrochemicals on human health and biodiversity.

Relationship between agrochemical compounds and mammary gland development and breast cancer

The exposure to agrochemical pesticides has been associated with several chronic diseases, including different types of cancer and reproductive disorders. In addition, because agrochemical pesticides may act as endocrine disrupting chemicals (EDCs) during different windows of susceptibility, they can increase the risk of impairing the normal development of the mammary gland and/or of developing mammary lesions. Therefore, the aim of this review is to summarize how exposure to different agrochemical pesticides suspected of being EDCs can interfere with the normal development of the mammary gland and the possible association with breast cancer. It has been shown that the mammary glands of male and female rats and mice are susceptible to exposure to non-organochlorine (vinclozolin, atrazine, glyphosate, chlorpyrifos) and organochlorine (endosulfan, methoxychlor, hexachlorobenzene) pesticides. Some of the effects of these compounds in experimental models include increased or decreased mammary development, impaired cell proliferation and steroid receptor expression and signaling, increased malignant cellular transformation and tumor development and angiogenesis. Contradictory findings have been found as to whether there is a causal link between the exposure or the pesticide body burden and breast cancer in humans. However, an association has been observed between pesticides (especially organochlorine compounds) and specific subtypes of breast cancer. Further studies are needed in both humans and experimental models to understand how agrochemical pesticides can induce or promote changes in the development, differentiation and/or malignant transformation of the mammary gland.

Integrated Approach to Evaluate the Association between Exposure to Pesticides and Idiopathic Premature Thelarche in Girls: The PEACH Project

Several pesticides are recognized as endocrine-disrupting chemicals (EDCs) since they can interfere with the dysregulation of sexual, thyroid and neuro-endocrine hormones. Children are particularly vulnerable to the adverse effects of EDCs due to their developmental stage, peculiar lifestyle and dietary habits. In this context, the exposure to pesticides represents an important risk factor associated with early development. This study deals with the possible association between exposure to pesticides and idiopathic premature thelarche in girls from areas of intensive agriculture practice in the Centre of Italy. An integrated approach was set up, including: (i) a case-control study on girls with idiopathic premature thelarche; (ii) the evaluation of multiple pesticides exposure in girls; (iii) the evaluation of multiple pesticides in food; (iv) the dietary intake of pesticide residues; (v) the assessment of toxicological effects of widely used pesticides by in vitro model. Data integration will provide an estimate of the predictive risk of potential effects on girls' health, linked to dietary intake.