Exposure to endocrine disruptors during adulthood: consequences for female fertility

Identification and quantification of novel per- and polyfluoroalkyl substances (PFAS) contamination in a Great Lakes urban-dominated watershed

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic organic fluoro-compounds that are oil-, water-, and flame-resistant, making them useful in a wide range of commercial and consumer products, as well as resistant to environmental degradation. To assess the impact of urbanization and wastewater treatment processes, surface water and sediment samples were collected at 27 sites within the Great Lakes in the Lake Huron to Lake Erie corridor (HEC), an international waterway including the highly urbanized Detroit and Rouge Rivers. Samples were analyzed for 92 PFAS via UHPLC-MS/MS. Our previous data in the HEC found the highest amount of PFAS contamination at the Rouge River mouth. In addition to evaluating the input of the Rouge River into the HEC, we evaluated the transport of PFAS into the HEC from other major tributaries. PFAS were detected in both surface water and sediment at all sites in this study, with a total of 10 congeners quantified in all surface water samples and 16 congeners quantified in all sediment samples, indicating ubiquitous contamination. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were pervasive in the HEC as these two compounds were detected in all sites and matrices, often at concentrations above the US EPA's recommended lifetime interim updated health advisories. Surface water samples contained more perfluorohexanoic acid (PFHxA) than any other congener, with average aqueous PFHxA across all surface water samples exceeding the average concentration previously reported in the Great Lakes. Sediment samples were dominated by PFOS, but novel congeners, notably 3-Perfluoropentyl propanoic acid (FPePA), were also quantified in sediment. The Rouge River and other tributaries contribute significantly to the PFAS burden in the HEC including Lake Erie. Overall, our results indicate the need for expanding toxicological research and risk assessment focused on congeners such as PFHxA and PFAS mixtures, as well as regulation that is tighter at the onset of production and encompasses PFAS as a group at a national level.

Mercury, natural fertility and outcomes of assisted reproduction: A systematic review

The primary route of mercury exposure for the general population is through consumption of contaminated seafood. There is a biological basis for an adverse effect of mercury exposure on human fertility. The goal of this review was to evaluate the existing literature on the association between mercury and pregnancy, among men and women attempting to conceive with and without assisted reproductive technology (ART). Systematic searches were performed in PubMed, EMBASE, Scopus and Web of Science for papers published up to March 2023 with no early date restriction, only including studies with a biomarker measurement of mercury exposure. We identified 11 studies examining mercury and natural fertility and 12 studies examining mercury and outcomes of assisted reproduction (implantation or clinical pregnancy). The accumulated evidence provides some support for a null association between bodily mercury concentrations and natural fertility among women, however, a large proportion of studies did not report adjusted estimates or were extremely imprecise. The majority of studies of natural fertility were also cross-sectional in nature. There was no evidence for an inverse or null association between mercury and natural fertility among men, or mercury and ART outcomes among men or women. In spite of biological plausibility, the existing evidence includes studies that are imprecise and often conflicting and does not allow us to make definitive conclusions on the associations of mercury exposure with successful pregnancy. Additional, larger studies are warranted, especially among individuals with high concentrations of mercury exposure as these individuals may be underrepresented in the current literature.

Ketoconazole blocks progesterone production without affecting other parameters of cumulus-oocyte complex maturation

Ketoconazole (KTZ) is widely used as a fungicide, but it is also known to target steroid hormone formation which may affect female reproductive health. Our study aims to investigate the effects of KTZ on in vitro matured bovine cumulus-oocyte complexes (COCs), as a model for female reproductive toxicity. Cumulus cells of in vitro maturing COCs produce progesterone and pregnenolone, but exposure to 10-6 M KTZ effectively blocked the synthesis of these hormones. Exposure to lower concentrations of KTZ (i.e. 10-7 M and 10-8 M) had no such effect on steroidogenesis compared to the 0.1 % v/v DMSO vehicle control. Classical parameters of in vitro COC maturation, such as oocyte nuclear maturation to the metaphase II stage and expansion of the cumulus investment, were not affected by any KTZ concentration tested. Apoptosis and necrosis levels were also not altered in cumulus cells or oocytes exposed to KTZ. Moreover, oocytes exposed to KTZ during maturation showed normal cleavage and early embryo development up to day 8 post fertilization; albeit a statistically significant decrease was observed in day 8 blastocysts produced from oocytes exposed to the lowest concentration of 10-8 M KTZ. When unexposed mature oocytes were fertilized, followed by embryo culture for 8 days under KTZ exposure, no adverse effects in embryo cleavage and blastocyst formation were observed. In conclusion, KTZ has no major impact on in vitro bovine oocyte maturation and blastocyst formation in our study, even at concentrations blocking steroidogenesis.

The alarming link between environmental microplastics and health hazards with special emphasis on cancer

Microplastic contamination is a burgeoning environmental issue that poses serious threats to animal and human health. Microplastics enter the human body through nasal, dermal, and oral routes to contaminate multiple organs. Studies have advocated the existence of microplastics in human breast milk, sputum, faeces, and blood. Microplastics can find their ways to the sub-cellular moiety via active and passive approaches. At cellular level, microplastics follow clathrin and caveolae-dependent pathways to invade the sub-cellular environment. These environmental contaminants modulate the epigenetic control of gene expression, status of inflammatory mediators, redox homeostasis, cell-cycle proteins, and mimic the endocrine mediators like estrogen and androgen to fuel carcinogenesis. Furthermore, epidemiological studies have suggested potential links between the exposure to microplastics and the onset of various chronic diseases. Microplastics trigger uncontrolled cell proliferation and ensue tissue growth leading to various cancers affecting the lungs, blood, breasts, prostate, and ovaries. Additionally, such contamination can potentially affect sub-cellular signaling and injure multiple organs. In essence, numerous reports have claimed microplastic-induced toxicity and tumorigenesis in human and model animals. Nonetheless, the underlying molecular mechanism is still elusive and warrants further investigations. This review provides a comprehensive analysis of microplastics, covering their sources, chemistry, human exposure routes, toxicity, and carcinogenic potential at the molecular level.

Malathion exposure may increase infertility risk among US Adults: Results from the 2015-2016 NHANES

BACKGROUND AND PURPOSE

Organophosphate pesticides such as malathion are the most widely used pesticides. Despite endocrine-disrupting effects, there is a paucity of information regarding chronic exposure to non-persistent organopesticides such as malathion. The purpose of this study is to describe the exposure burden among U.S. residents as well as possible impacts on fertility.

METHODS

Population-based data collected by the National Health and Nutrition Examination Survey (NHANES) between 2015 and 2016 were used to perform a retrospective analysis on urinary concentrations of malathion diacid. Samples were assessed from 1703 adult participants, statistically weighted to represent over 231 million individuals. General linear models were used to examine associations between exposure and reproductive health measures among pre-menopausal women.

RESULTS

Detectable concentrations of malathion diacid were identified in 16.1 % (n = 254) of samples. Concentrations were higher among women who reported seeing a physician due to difficulties becoming pregnant (P < 0.001; r2 = 0.12) as well as among women who reported trying for at least a year to become pregnant (P < 0.001; r2 = 0.06).

CONCLUSIONS

Exposure to malathion is associated with a history of reproductive health challenges among women.

Exposure to urban ambient particles (PM2.5) before pregnancy affects the expression of endometrial receptive markers to embryo implantation in mice: Preliminary results

Air pollution (AP) is one of the main recent concerns in reproductive healthy due to its potential to promote negative outcomes during pregnancy and male and female fertility. Several studies have demonstrated that AP exposure has been linked to increased embryonic implantation failures, alterations in embryonic, fetal and placental development. For a well-succeeded implantation, both competent blastocyst and receptive endometrium are required. Based on the lack of data about the effect of AP in endometrial receptivity, this study aimed to evaluate he particulate matter (PM) exposure impact on uterine receptive markers in mice and associate the alterations to increased implantation failures due to AP. For this study, ten dams per group were exposed for 39 days to either filter (F) or polluted air (CAP). At fourth gestational day (GD4), females were euthanized. Morphological, ultrastructural, immunohistochemical and molecular analysis of uterine and ovarian samples were performed. CAP-exposed females presented a reduced number of corpus luteum; glands and epithelial cells were increased with pinopodes formation impairment. Immunohistochemistry analysis revealed decreased LIF protein levels. These preliminary data suggests that PM exposure may exert negative effects on endometrial receptivity by affecting crucial parameters to embryonic implantation as uterine morphological differentiation, corpus luteum quantity and LIF expression during implantation window.

Tanshinone IIA from Salvia miltiorrhiza alleviates follicular maturation arrest symptoms in zebrafish via binding to the human androgen receptors and modulating Tox3 and Dennd1a

Follicular maturation arrest is a prevalent endocrine disorder characterized by hormonal imbalance, ovarian dysfunction, and metabolic disturbances leading to Polycystic ovarian syndrome (PCOS). Tanshinone IIA (TIIA), a bioactive compound derived from Salvia miltiorrhiza, has shown promising therapeutic potential in various diseases, including cardiovascular diseases and cancer. However, its effects on reproductive health and gynecological disorders, particularly PCOS, remain poorly understood. In this study, we investigated the potential therapeutic effects of TIIA on ovarian function. Using a combination of experimental and computational approaches, we elucidated the molecular mechanisms underlying TIIA's pharmacological impact on ovarian function, follicular development, and androgen receptor signaling. Molecular docking and dynamics simulations revealed that TIIA interacts with the human androgen receptor (HAR), modulating its activity and downstream signaling pathways. Our results demonstrate that TIIA treatment alleviates PCOS-like symptoms in a zebrafish model, including improved follicular development, lowered GSI index, improved antioxidant status (SOD, CAT), decreased LDH levels, and enhanced AChE levels by regulating Tox3 and Dennd1a pathway. Our findings suggest that TIIA may hold promise as a novel therapeutic agent for the management of PCOS or ovulation induction.

Unveiling the intricacies of BPA and BPS: comprehensive insights into its toxic effects using a cutting-edge microphysiological system

Concerns over Bisphenol A (BPA) and its substitute, Bisphenol S (BPS), have led to innovative exploration due to potential adverse health effects. BPS, replacing BPA in some regions to avoid toxic impacts, remains insufficiently studied. Besides this, the organ-on-a-chip technology emerges as a transformative solution in drug discovery and chemiclas toxicity testing, minimizing costs and aligning with ethical standards by reducing reliance on animal models, by integrating diverse tissues and dynamic cell environments enhances precision in predicting organ function. Here, we employ a 3-organ-on-a-chip microfluidic device with skin, intestine, and liver cultures to assess the effects of BPA and BPS via topical and oral administration. Our evaluation focused on gene markers associated with carcinogenicity, systemic toxicity, and endocrine disruption. BPA exhibited expected absorption profiles, causing liver injury and genetic modulation in related pathways. BPS, a safer alternative, induced adverse effects on gene expression, particularly in topical absorption, with distinct absorption patterns. Our findings underscore the urgency of addressing BPA and BPS toxicity concerns, highlighting the crucial role of organ-on-a-chip technology in understanding associated health risks. The study promotes the organ-on-a-chip methodology as a valuable tool for safe drug development and disease treatments, offering a novel liver toxicity screening alternative to traditional animal tests. This contributes to advancing comprehension of the biological effects of these compounds, fostering improved safety assessments in human health.

Association Between Exposure to Multiple Toxic Metals in Follicular Fluid and the Risk of PCOS Among Infertile Women: The Mediating Effect of Metabolic Markers

Polycystic ovary syndrome (PCOS) severely affects women's fertility and accompanies serious metabolic disturbances, affecting 5%-20% of women of reproductive age globally. We previously found that exposure to toxic metals in the blood raised the risk of PCOS, but the association between exposure to toxic metals and the risk of PCOS in the follicular fluid, the microenvironment for oocyte growth and development in females, and its effect on metabolism has not been reported. This study aimed to evaluate the associations between the concentrations of cadmium (Cd), mercury (Hg), barium (Ba) and arsenic (As) in FF and the risk of PCOS, and to explore the mediating effect of metabolic markers in FF on the above relationship. We conducted a case-control study, including 557 women with PCOS and 651 controls. Ba, Cd, Hg and As levels in FF were measured by ICP-MS, metabolites levels in FF was measured by LC-MS/MS among 168 participants randomly selected from all the participants. Logistic regression models were used to assess the association of a single metal level with the PCOS risk, and linear regression models were used to assess the relationships of a single metal level with clinical phenotype parameters and metabolites levels. Combined effect of metals mixture levels on the risk of PCOS were assessed via weighted quantile sum (WQS) regression and bayesian kernel machine regression (BKMR). Medication analysis was performed to explore the role of metabolic markers on the relationship of toxic metals levels with the risk of PCOS. The exposure levels of Cd, Hg, Ba and As in FF were all positively and significantly associated with the PCOS risk (with respect to the highest vs. lowest tertile group: OR = 1.57, 95% CI = 1.17 ~ 2.12 for Cd, OR = 1.69, 95% CI = 1.22 ~ 2.34 for Hg, OR = 1.76, 95% CI = 1.32 ~ 2.34 for Ba, OR = 1.42, 95% CI = 1.05 ~ 1.91 for As). In addition, levels of metal mixture also significantly correlated with the risk of PCOS, Cd level contributed most to it. Moreover, we observed significant positive relationships between Cd level and LH (β = 0.048, 95% CI = 0.002 ~ 0.094), T (β = 0.077, 95% CI = 0.029 ~ 0.125) and HOMA-IR value (β = 0.060, 95% CI = 0.012 ~ 0.107), as well as Hg level with LH, FSH/LH ratio and TC. Furthermore, we revealed that estrone sulfate, LysoPE 22:6 and N-Undecanoylglycine were significantly and positively mediating the association between Cd level and the risk of PCOS (with mediated proportion of 0.39, 0.24 and 0.35, respectively), and between Hg level and the risk of PCOS (with mediated proportion of 0.29, 0.20 and 0.46, respectively). These highly expressed metabolites significantly enriched in the fatty acid oxidation, steroid hormone biosynthesis and glycerophospholipids metabolism, which may explain the reason why the levels of Cd and Hg in FF associated with the phenotype of PCOS. Ba and As in FF was not found the above phenomenon. Our results suggested that exposure to multiple toxic metals (Cd, Hg, Ba and As) in FF associated with the increased risk of PCOS, Cd was a major contributor. Levels of Cd and Hg in FF significantly associated with the phenotype of PCOS. The above association may result from that Cd and Hg in FF related with the disturbance of fatty acid oxidation, steroid hormone biosynthesis and the glycerophospholipids metabolism.

Omics technology draws a comprehensive heavy metal resistance strategy in bacteria

The rapid industrial revolution significantly increased heavy metal pollution, becoming a major global environmental concern. This pollution is considered as one of the most harmful and toxic threats to all environmental components (air, soil, water, animals, and plants until reaching to human). Therefore, scientists try to find a promising and eco-friendly technique to solve this problem i.e., bacterial bioremediation. Various heavy metal resistance mechanisms were reported. Omics technologies can significantly improve our understanding of heavy metal resistant bacteria and their communities. They are a potent tool for investigating the adaptation processes of microbes in severe conditions. These omics methods provide unique benefits for investigating metabolic alterations, microbial diversity, and mechanisms of resistance of individual strains or communities to harsh conditions. Starting with genome sequencing which provides us with complete and comprehensive insight into the resistance mechanism of heavy metal resistant bacteria. Moreover, genome sequencing facilitates the opportunities to identify specific metal resistance genes, operons, and regulatory elements in the genomes of individual bacteria, understand the genetic mechanisms and variations responsible for heavy metal resistance within and between bacterial species in addition to the transcriptome, proteome that obtain the real expressed genes. Moreover, at the community level, metagenome, meta transcriptome and meta proteome participate in understanding the microbial interactive network potentially novel metabolic pathways, enzymes and gene species can all be found using these methods. This review presents the state of the art and anticipated developments in the use of omics technologies in the investigation of microbes used for heavy metal bioremediation.

Hues of risk: investigating genotoxicity and environmental impacts of azo textile dyes

The textile industry, with its extensive use of dyes and chemicals, stands out as a significant source of water pollution. Exposure to certain textile dyes, such as azo dyes and their breakdown products like aromatic amines, has been associated with health concerns like skin sensitization, allergic reactions, and even cancer in humans. Annually, the worldwide production of synthetic dyes approximates 7 × 107 tons, of which the textile industry accounts for over 10,000 tons. Inefficient dyeing procedures result in the discharge of 15-50% of azo dyes, which do not adequately bind to fibers, into wastewater. This review delves into the genotoxic impact of azo dyes, prevalent in the textile industry, on aquatic ecosystems and human health. Examining different families of textile dye which contain azo group in their structure such as Sudan I and Sudan III Sudan IV, Basic Red 51, Basic Violet 14, Disperse Yellow 7, Congo Red, Acid Red 26, and Acid Blue 113 reveals their carcinogenic potential, which may affect both industrial workers and aquatic life. Genotoxic and carcinogenic characteristics, chromosomal abnormalities, induced physiological and neurobehavioral changes, and disruptions to spermatogenesis are evident, underscoring the harmful effects of these dyes. The review calls for comprehensive investigations into the toxic profile of azo dyes, providing essential insights to safeguard the aquatic ecosystem and human well-being. The importance of effective effluent treatment systems is underscored to mitigate adverse impacts on agricultural lands, water resources, and the environment, particularly in regions heavily reliant on wastewater irrigation for food production.

Phthalates are detected in the follicular fluid of adolescents and oocyte donors with associated changes in the cumulus cell transcriptome

Purpose

To investigate follicular fluid (FF) phthalate levels in adolescents undergoing fertility preservation compared to oocyte donors and explore its association with ovarian reserve and cumulus cell gene expression.

Methods

20 Adolescents (16.7 ± 0.6 years old) and 24 oocyte donors (26.2 ± 0.4 years old) undergoing fertility preservation were included in the study. Patient demographics, ovarian stimulation and oocyte retrieval outcomes were analyzed for each group. FF levels of 9 phthalate metabolites were assessed individually and as molar sums representative of common compounds (all phthalates: ΣPhthalates; DEHP: ΣDEHP), exposure sources (plastics: ΣPlastic; personal care products: ΣPCP), and modes of action (anti-androgenic: ΣAA) and compared between the two groups.

Results

Follicular fluid ΣPlastic and ΣPCP levels were significantly higher in adolescents compared to oocyte donors (p<0.05). Follicular fluid ΣDEHP, ΣPlastic, ΣPCP, ΣAA, and ΣPhthalates levels were positively associated with antral follicle count (AFC) (p<0.05) in oocyte donors when adjusted for age, BMI, and race/ethnicity. RNA-seq analysis revealed 248 differentially expressed genes (DEGs) in cumulus cells of adolescents within the top quartile (n=4) of FF ΣPhthalates levels compared to the adolescents within the bottom half (n=9). Genes enriched in pathways involved in cell motility and development were significantly downregulated.

Conclusion

Adolescents undergoing fertility preservation cycles demonstrate higher levels of phthalate metabolites in their follicular fluid compared to oocyte donors. Phthalate metabolite levels in FF are associated with higher AFC levels in oocyte donors. Higher phthalate levels in FF are associated with alterations in the cumulus cells transcriptome in adolescents.

Association between per- and polyfluoroalkyl substances exposure and thyroid function biomarkers among females attending a fertility clinic

Per- and polyfluoroalkyl substances (PFAS) exposure was associated with changes in thyroid function in pregnant mothers and the general population. Limited such evidence exists in other susceptible populations such as females with fertility problems. This cross-sectional study included 287 females seeking medically assisted reproduction at a fertility clinic in Massachusetts, United States, between 2005 and 2019. Six long-alkyl chain PFAS, thyroid hormones, and autoimmune antibodies were quantified in baseline serum samples. We used generalized linear models and quantile g-computation to evaluate associations of individual PFAS and their total mixture with thyroid biomarkers. Most females were White individuals (82.7%), had graduate degrees (57.8%), and nearly half had unexplained subfertility (45.9%). Serum concentrations of all examined PFAS and their mixture were significantly associated with 2.6%-5.6% lower total triiodothyronine (TT3) concentrations. Serum concentrations of perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluoroundecanoate (PFUnDA), and of the total mixture were associated with higher ratios of free thyroxine (FT4) to free triiodothyronine (FT3). No associations were found for PFAS and TSH or autoimmune antibodies. Our findings support the thyroid-disrupting effect of long alkyl-chain PFAS among a vulnerable population of subfertile females.

Development of A Liquid-Phase Microextraction Method for Simultaneous Determination of Parabens in Lipstick Samples at Trace Levels by High-Performance Liquid Chromatography

The endocrine-disrupting potential of parabens, as well as their relation to cancer, has sparked significant discussions over their impact. Consequently, analyses of cosmetic products are an essential necessity, particularly in terms of human health and safety. In this study, a highly accurate and sensitive liquid-phase-based microextraction method was developed to determine the five parabens at trace levels by high-performance liquid chromatography. All prominent parameters of the method such as extraction solvent type and amount (1,2-dichloroethane/250 μL), and dispersive solvent type and amount (isopropyl alcohol/2.0 mL) were optimized to enhance the extraction efficiency of the analytes. The mobile phase consisting of 50 mM ammonium formate aqueous solution (pH 4.0) and acetonitrile (60:40, v/v) was used to elute the analytes at a flow rate of 1.2 mL min-1 in the isocratic mode. Analytical performance of the optimum method for methyl, ethyl, propyl, butyl and benzyl parabens were determined and the analytes recorded detection limit values of 0.78, 0.75, 0.34, 0.33 and 0.75 μg kg-1, respectively. Four different lipstick samples were analyzed under optimum conditions of the developed method, and the amount of parabens quantified in the samples using matrix matched calibration standards was in the range of 0.11-1.03%.

A high throughput CRISPR perturbation screen identifies epigenetic regulators impacting primordial germ cell development

Certain environmental factors can impact fertility and reproductive parameters such as the number and quality of sperm and eggs. One possible mechanism is the perturbation of epigenetic landscapes in the germline. To explore this possibility, we conducted a CRISPRi screen of epigenetic-related genes to identify those that specifically perturb the differentiation of embryonic stem cells (ESCs) into primordial germ cell-like cells (PGCLCs), exploiting a highly scalable cytokine-free platform. Of the 701 genes screened, inhibition of 53 decreased the efficiency of PGCLC formation. NCOR2, a transcriptional repressor that acts via recruitment of Class I and Class IIa histone deacetylases (HDACs) to gene targets, was particularly potent in suppressing PGCLC differentiation. Consistent with evidence that histone deacetylation is crucial for germline differentiation, we found that the HDAC inhibitors (HDACi) valproic acid (VPA; an anti-convulsant) and sodium butyrate (SB; a widely-used dietary supplement) also suppressed ESC>PGCLC differentiation. Furthermore, exposure of developing mouse embryos to SB or VPA caused hypospermatogenesis. Transcriptome analyses of HDACi-treated, differentiating ESC>PGCLC cultures revealed suppression of germline-associated pathways and enhancement of somatic pathways. This work demonstrates the feasibility of conducting large-scale functional screens of genes, chemicals, or other agents that may impact germline development.

Pesticides exposure and compromised fitness in wild birds: Focusing on the reproductive endocrine disruption

Exposure of pesticides to wildlife species, especially on the aspect of endocrine disruption is of great concern. Wildlife species are more at risk to harmful exposures to the pesticides in their natural habitat through diet and several other means. Species at a higher tropic level in the food chain are more susceptible to the deleterious effects due to sequential biomagnifications of the pesticides/metabolites. Pesticides directly affect fitness of the species in the wild causing reproductive endocrine disruption impairing the hormones of the gonads and thyroid glands as reproduction is under the influence of cross regulations of these hormones. This review presents a comprehensive compilation of important literatures on the impact of the current use pesticides in disruption of both the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-thyroid axes particularly in birds addressing impacts on the reproductive impairments and overall fitness. In addition to the epidemiological studies, laboratory investigations those provide supportive evidences of the probable mechanisms of disruption in the wild also have been incorporated in this review. To accurately predict the endocrine-disruption of the pesticides as well as to delineate the risk associated with potential cumulative effects, studies are to be more focused on the environmentally realistic exposure dose, mixture pesticide exposures and transgenerational effects. In addition, strategic screening/appropriate methodologies have to be developed to reveal the endocrine disruption potential of the contemporary use pesticides. Demand for adequate quantitative structure-activity relationships and insilico molecular docking studies for timely validation have been highlighted.

The adverse role of endocrine disrupting chemicals in the reproductive system

Reproductive system diseases pose prominent threats to human physical and mental well-being. Besides being influenced by genetic material regulation and changes in lifestyle, the occurrence of these diseases is closely connected to exposure to harmful substances in the environment. Endocrine disrupting chemicals (EDCs), characterized by hormone-like effects, have a wide range of influences on the reproductive system. EDCs are ubiquitous in the natural environment and are present in a wide range of industrial and everyday products. Currently, thousands of chemicals have been reported to exhibit endocrine effects, and this number is likely to increase as the testing for potential EDCs has not been consistently required, and obtaining data has been limited, partly due to the long latency of many diseases. The ability to avoid exposure to EDCs, especially those of artificially synthesized origin, is increasingly challenging. While EDCs can be divided into persistent and non-persistent depending on their degree of degradation, due to the recent uptick in research studies in this area, we have chosen to focus on the research pertaining to the detrimental effects on reproductive health of exposure to several EDCs that are widely encountered in daily life over the past six years, specifically bisphenol A (BPA), phthalates (PAEs), polychlorinated biphenyls (PCBs), parabens, pesticides, heavy metals, and so on. By focusing on the impact of EDCs on the hypothalamic-pituitary-gonadal (HPG) axis, which leads to the occurrence and development of reproductive system diseases, this review aims to provide new insights into the molecular mechanisms of EDCs' damage to human health and to encourage further in-depth research to clarify the potentially harmful effects of EDC exposure through various other mechanisms. Ultimately, it offers a scientific basis to enhance EDCs risk management, an endeavor of significant scientific and societal importance for safeguarding reproductive health.

The environmental occurrence, fate, and risks of 25 endocrine disruptors in Slovenian waters

Natural hormones, synthetic steroids and bisphenols are among the most active endocrine disruptors (EDs) in the aquatic environment, with great potential for causing adverse effects in aquatic organisms and humans. In this study, a focused group of 25 potent estrogenic and other ED compounds were simultaneously measured in wastewaters (WWs) and receiving surface waters (SWs) before and after wastewater treatment plants (WWTPs), where their removal efficiency was also estimated. Up to 16 of 25 EDs were successfully quantified in SWs and WWs, with bisphenols BPS, BPA, and BPF together with estriol and chlormadinone being the most prevalent with the highest measured concentrations of up to 35 μg/L in WWs and 400 ng/L in SWs. High load and insufficient removal of these substances by WWTPs lead to a significant increase in their concentrations in the receiving SWs downstream, while other sources could be responsible for an important portion of river contamination with EDs. Removal efficiency was very good for most EDs, although only from 0 to 44 % for E2, which shows a need for the improvement of current removal techniques. E2 and EE2 contribute the most to the alarmingly high risks of the total ED estrogenic potential, with the value increased by 36 % in SWs downstream from WWTPs, and the RQ value for the total estrogenic potential in individual SW samples being three orders of magnitude higher than that representing high risk. An additional comprehensive multi-parameter risk assessment determined high risk quotient and priority index values for BPA, E2, BPS and E1 with values of up to 450 in SWs. Our results show a focused insight into the risks associated with an important group of EDs and the role of WWTPs, while further highlighting the importance of regular monitoring of the environmental occurrence and risks of a focused range of EDs.

Mechanism Exploration of Environmental Pollutants on Premature Ovarian Insufficiency: a Systematic Review and Meta-analysis

As a public health problem, premature ovarian insufficiency leads to infertility or sub-fertility. In addition to premature ovarian insufficiency (POI) increases the lifetime risk of bone fragility, cardiovascular disease, and cognitive impairment. To investigate the effects of environmental pollutants on the occurrence of POI and explore its mechanism, we conducted a computer search for articles published in electronic databases by December 13, 2022. Three reviewers independently examined all included studies and scored the qualities of included studies using the Newcastle-Ottawa Scale criteria. In this meta-analysis, eight clinical studies as well as ten preclinical findings showed a pooled OR of 2.331 and 95% CI of 1.968-2.760. This confirms that environmental pollutants, including POPs, heavy metals, PAEs, PAHs, cosmetic and pharmaceutical products, and cigarette smoke, are indeed significant risk factors for POI. In addition, it is demonstrated from the results of this study that signaling pathway of calcium and PI3K Akt and Xpnpep2, Col1, Col3, Col4, Cx43, Egr3, Tff1, and Ptgs2 genes may all be involved in the process. Environmental pollutants, including POPs, heavy metals, PAEs, PAHs, cosmetic and pharmaceutical products, and cigarette smoke, are indeed significant risk factors for POI.

Endocrine-disrupting chemicals and male reproductive health

Modifiable factors, such as environmental exposures, can impact human fertility. The objective of this review is to summarize the potential effects of exposure to important endocrine-disrupting chemicals on male reproductive health. Most experimental and animal data demonstrate strong evidence for the negative effects of exposure to phenols, phthalates, pesticides, and perfluoroalkyl and polyfluoroalkyl substances on male reproductive health. Although evidence of negative associations in humans was overall strong for phthalates and pesticides, limited and inconclusive relationships were found for the other examined chemical biomarkers. Reasons for the discrepancies in results include but are not limited to, differences in study populations, exposure concentrations, number of samples collected, sample sizes, study design, and residual confounding. Additional studies are needed, particularly for newer phenols and perfluoroalkyl and polyfluoroalkyl substances, given the scarce literature on the topic and increasing exposures over time.

Placental single cell transcriptomics: Opportunities for endocrine disrupting chemical toxicology

The placenta performs essential biologic functions for fetal development throughout pregnancy. Placental dysfunction is at the root of multiple adverse birth outcomes such as intrauterine growth restriction, preeclampsia, and preterm birth. Exposure to endocrine disrupting chemicals during pregnancy can cause placental dysfunction, and many prior human studies have examined molecular changes in bulk placental tissues. Placenta-specific cell types, including cytotrophoblasts, syncytiotrophoblasts, extravillous trophoblasts, and placental resident macrophage Hofbauer cells play unique roles in placental development, structure, and function. Toxicant-induced changes in relative abundance and/or impairment of these cell types likely contribute to placental pathogenesis. Although gene expression insights gained from bulk placental tissue RNA-sequencing data are useful, their interpretation is limited because bulk analysis can mask the effects of a chemical on individual populations of placental cells. Cutting-edge single cell RNA-sequencing technologies are enabling the investigation of placental cell-type specific responses to endocrine disrupting chemicals. Moreover, in situ bioinformatic cell deconvolution enables the estimation of cell type proportions in bulk placental tissue gene expression data. These emerging technologies have tremendous potential to provide novel mechanistic insights in a complex heterogeneous tissue with implications for toxicant contributions to adverse pregnancy outcomes.

Intergenerational effects on fertility in male and female mice after chronic exposure to environmental doses of NSAIDs and 17α-ethinylestradiol mixtures

Non-steroidal anti-inflammatory drugs (NSAIDs) and 17α-ethinylestradiol (EE2) are extensively used in human and veterinary medicine. Due to their partial removal by wastewater treatment plants, they are frequent environmental contaminants, particularly in drinking water. Here, we investigated the adverse outcomes of chronic exposure to mixtures of NSAIDs (ibuprofen, 2hydroxy-ibuprofen, diclofenac) and EE2 at two environmentally relevant doses in drinking water, on the reproductive organ development and fertility in F1-exposed male and female mice and in their F2 offspring. In male and female F1 mice, which were exposed to these mixtures, reproductive organ maturation, estrous cyclicity, and spermiogenesis were altered. These defects were observed also in F2 animals, in addition to some specific sperm parameter alterations in F2 males. Transcriptomic analysis revealed significant changes in gene expression patterns and associated pathways implicated in testis and ovarian physiology. Chronic exposure of mice to NSAID and EE2 mixtures at environmental doses intergenerationally affected male and female fertility (i.e. total number of pups and time between litters). Our study provides new insights into the adverse effects of these pharmaceuticals on the reproductive health and will facilitate the implementation of a future regulatory environmental risk assessment of NSAIDs and EE2 for human health.

Hormonal Injustice: Environmental Toxicants as Drivers of Endocrine Health Disparities

The toll of multiple endocrine disorders has increased substantially in recent decades, and marginalized populations bear a disproportionate burden of disease. Because of the significant individual and societal impact of these conditions, it is essential to identify and address all modifiable risk factors contributing to these disparities. Abundant evidence now links endocrine dysfunction with exposure to endocrine-disrupting chemicals (EDCs), with greater exposures to multiple EDCs occurring among vulnerable groups, such as racial/ethnic minorities, those with low incomes, and others with high endocrine disease burdens. Identifying and eliminating EDC exposures is an essential step in achieving endocrine health equity.

Does bisphenol A (BPA) participates in the pathogenesis of Polycystic Ovary Syndrome (PCOS)?

PCOS is an endocrine disorder characterized by chronic anovulation, hyperandrogenism, and polycystic ovaries. Its etiology is uncertain. It is debated whether BPA would be a component of the environmental factor in the etiology of PCOS. Contamination by BPA can occur from food packaging (exposure during the diet) and through skin absorption and/or inhalation. It can be transferred to the fetus via the placenta or to the infant via breast milk, and it can be found in follicular fluid, fetal serum, and amniotic fluid. The phenolic structure of BPA allows it to interact with Estrogen Receptors (ERs) through genomic signaling, in which BPA binds to nuclear ERα or Erβ, or through nongenomic signaling by binding to membrane ERs, prompting a rapid and intense response. With daily and constant exposure, BPA's tendency to bioaccumulate and its ability to activate nongenomic signaling pathways can alter women's metabolic and reproductive function, leading to hyperandrogenism, insulin resistance, obesity, atherogenic dyslipidemia, chronic inflammatory state, and anovulation and favoring PCOS. The harmful changes caused by BPA can be passed on to future generations without the need for additional exposure because of epigenetic modifications. Not only high BPA levels can produce harmful effects, but at low levels, BPA may be harmful when exposure occurs during the most vulnerable periods, such as the fetal and neonatal periods, as well as during the prepubertal age causing an early accumulation of BPA in the body. Learning how BPA participates in the pathogenesis of PCOS poses a challenge and further studies should be conducted.

Preconception and developmental DEHP exposure alter liver metabolism in a sex-dependent manner in adult mouse offspring

Environmental exposure to endocrine disrupting chemicals (EDCs) during critical periods of development is associated with an increased risk of metabolic diseases, including hepatic steatosis and obesity. Di-2-ethylhexyl-phthalate (DEHP) is an EDC strongly associated with these metabolic abnormalities. DEHP developmental windows of susceptibility are unknown yet have important public health implications. The purpose of this study was to identify these windows of susceptibility and determine whether developmental DEHP exposure alters hepatic metabolism later in life. Dams were exposed to control or feed containing human exposure relevant doses of DEHP (50 μg/kg BW/d) and high dose DEHP (10 mg/kg BW/d) from preconception until weaning or only exposed to DEHP during preconception. Post-weaning, all offspring were fed a control diet throughout adulthood. Using the Metabolon Untargeted Metabolomics platform, we identified 148 significant metabolites in female adult livers that were altered by preconception-gestation-lactation DEHP exposure. We found a significant increase in the levels of acylcarnitines, diacylglycerols, sphingolipids, glutathione, purines, and pyrimidines in DEHP-exposed female livers compared to controls. These changes in fatty acid oxidation and oxidative stress-related metabolites were correlated with hepatic changes including microvesicular steatosis, hepatocyte swelling, inflammation. In contrast to females, we observed fewer metabolic alterations in male offspring, which were uniquely found in preconception-only low dose DEHP exposure group. Although we found that preconception-gestational-lactation exposure causes the most liver pathology, we surprisingly found preconception exposure linked to an abnormal liver metabolome. We also found that two doses exhibited non-monotonic DEHP-induced changes in the liver. Collectively, these findings suggest that metabolic changes in the adult liver of offspring exposed periconceptionally to DHEP depends on the timing of exposure, dose, and sex.

Exploration of the correlation of serum polychlorinated biphenyl levels with luteal phase hormonal parameters and infertility in women with or without polycystic ovary syndrome

Introduction

Polychlorinated biphenyls (PCBs) are organic lipophilic pollutants that accumulate in the body. Previous research has linked PCBs with menstrual function; therefore, this study was undertaken to investigate the correlation of PCBs with luteal phase hormonal parameters of menstrual function at day 21 in a group of non-obese women prior to in vitro fertilization (IVF).

Methods

Fifty-eight non-obese Caucasian women from a UK academic center, 29 with polycystic ovary syndrome (PCOS) and 29 without, were recruited. PCOS women all had anovulatory infertility. Non-PCOS women: five with unexplained infertility, the remainder with male factor infertility (n=14) or tubal problems (n=10). Blood was withdrawn at day 21 of the menstrual cycle for non-PCOS women, at the time of mock embryo transfer. PCBs were measured using high resolution gas chromatography.

Results

Only PCB118, PCB153, PCB138 and PCB180 were detected in all samples, and levels did not differ between PCOS and non-PCOS subjects. In non-PCOS subjects, PCB153, PCB138 and PCB180 inversely correlated with estradiol (p<0.05); PCB118 and PCB138 inversely correlated with follicle stimulating hormone (FSH) (p<0.05); PCB118 (p<0.05), PCB153, PCB138 and PCB180 (all p<0.01) inversely correlated with luteinizing hormone (LH). Control women without PCOS with unexplained infertility showed higher levels of PCB118, PCB153, PCB138 and PCB180 (p<0.05) compared to those control women without PCOS with tubal or male factor infertility, though other hormonal parameters did not differ other than that FSH that was lower in the unexplained group (p=0.01). The only correlation observed in PCOS women with anovulatory infertility was that between PCB180 and progesterone (p<0.05).

Conclusion

PCBs correlated with luteal phase menstrual cycle hormones in control women without PCOS and may contribute to the mechanism of unexplained infertility; in PCOS women, no correlations of the PCBs were seen for estradiol, LH or FSH.

Exposure to air pollution and risk of ovarian cancer: a review

OBJECTIVES

Exposure to air pollution has destructive health consequences and a potential role in ovarian cancer etiology. We conducted a systematic review of the studies assessing the associations between ovarian malignancy and exposure to air pollutants.

CONTENT

The included studies were categorized based on types of measured ambient air pollutants, including particulate matter (five studies), gases (two studies), air pollutant mixtures (eight studies), and traffic indicators for air pollution (only one study). Because of the heterogeneity of quantitative data of the reviewed studies, we qualitatively reviewed the air pollution role in ovarian cancer risk with representing incidence and/or the mortality rate of ovarian cancer in related with air pollution. Nine studies were ecological study design. Except for one, all studies confirmed a positive correlation between exposure to ambient air pollution (AAP) and increased ovarian cancer risks.

SUMMARY

We concluded that prolonged air pollution exposure through possible mechanisms, estrogen-like effects, and genetic mutations might affect ovarian tumorigenesis. This research surveyed the limitations of the previous studies, including issues with ambient air pollution surveillance and assessing the exposure, determining the air pollution sources, data analysis approaches, and study designs.

OUTLOOK

Finally, the authors provide suggestions for future environmental epidemiological inquiries on the impact of exposure to ambient air pollution on ovarian malignancy.

Associations between Urinary Concentrations of Disinfection Byproducts and in Vitro Fertilization Outcomes: A Prospective Cohort Study in China

BACKGROUND

Experimental studies show that disinfection byproducts (DBPs) can inhibit oocyte maturation, decrease fertilization capacity, and impair embryo development, but human evidence is lacking.

OBJECTIVES

We aimed to evaluate the associations between exposure to drinking water DBPs and in vitro fertilization (IVF) outcomes.

METHODS

The study included 1,048 women undergoing assisted reproductive technology (ART) treatment between December 2018 and January 2020 from a prospective cohort study, the Tongji Reproductive and Environmental study in Wuhan, China. Exposure to DBPs was assessed by dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in up to four urine samples, which were collected on the day of both enrollment and oocyte retrieval. Multivariable generalized linear mixed models, accounting for multiple IVF cycles per woman, were applied to evaluate the associations between urinary biomarkers of DBP exposures and IVF outcomes. Stratified analyses were used to explore the potential effect modifiers.

RESULTS

The included 1,048 women underwent 1,136 IVF cycles, with 960 (91.6%), 84 (8.0%), and 4 (0.4%) women contributing one cycle, two cycles, and three cycles, respectively. We found that elevated quartiles of urinary DCAA and TCAA concentrations were associated with reduced numbers of total oocytes and metaphase II oocytes and that urinary DCAA concentrations with a lower proportion of best-quality embryos (all p for trends < 0.05 ). Moreover, elevated quartiles of urinary DCAA concentrations were associated with decreased proportions of successful implantation, clinical pregnancy, and live birth (14%, 15%, and 15% decreases in adjusted means comparing the extreme quartiles, respectively; all p for trends < 0.05 ). Stratification analyses showed that the inverse associations of urinary TCAA concentrations with multiple IVF outcomes were stronger among women ≥ 30 y of age (p for interactions < 0.05 ).

DISCUSSION

Exposure to drinking water DBPs was inversely associated with some IVF outcomes among women undergoing ART treatment. Further study is necessary to confirm our findings. https://doi.org/10.1289/EHP12447.

Hepatic and ovarian effects of perfluorooctanoic acid exposure differ in lean and obese adult female mice

Obesity and overweight cause poor oocyte quality, miscarriage, infertility, polycystic ovarian syndrome, and offspring birth defects and affects 40% and 20% of US women and girls, respectively. Perfluorooctanoic acid (PFOA), a per- and poly-fluoroalkyl substance (PFAS), is environmentally persistent and has negative female reproductive effects including endocrine disruption, oxidative stress, altered menstrual cyclicity, and decreased fertility in humans and animal models. PFAS exposure is associated with non-alcoholic fatty liver disease which affects ∼24-26% of the US population. This study investigated the hypothesis that PFOA exposure impacts hepatic and ovarian chemical biotransformation and alters the serum metabolome. At 7 weeks of age, female lean, wild type (KK.Cg-a/a) or obese (KK.Cg-Ay/J) mice received saline (C) or PFOA (2.5 mg/Kg) per os for 15 d. Hepatic weight was increased by PFOA exposure in both lean and obese mice (P < 0.05) and obesity also increased liver weight (P < 0.05) compared to lean mice. The serum metabolome was also altered (P < 0.05) by PFOA exposure and differed between lean and obese mice. Exposure to PFOA altered (P < 0.05) the abundance of ovarian proteins with roles in xenobiotic biotransformation (lean - 6; obese - 17), metabolism of fatty acids (lean - 3; obese - 9), cholesterol (lean - 8; obese - 11), amino acids (lean - 18; obese - 19), glucose (lean - 7; obese - 10), apoptosis (lean - 18; obese - 13), and oxidative stress (lean - 3; obese - 2). Use of qRT-PCR determined that exposure to PFOA increased (P < 0.05) hepatic Ces1 and Chst1 in lean but Ephx1 and Gstm3 in obese mice. Also, obesity basally increased (P < 0.05) Nat2, Gpi and Hsd17b2 mRNA levels. These data identify molecular changes resultant from PFOA exposure that may cause liver injury and ovotoxicity in females. In addition, differences in toxicity induced by PFOA exposure occurs in lean and obese mice.

Potential biomarkers to predict return to fertility after discontinuation of female contraceptives-looking to the future

Nowadays there are multiple types of contraceptive methods, from reversible to permanent, for those choosing to delay pregnancy. Misconceptions about contraception and infertility are a key factor for discontinuation or the uptake of family planning methods. Regaining fertility (the ability to conceive) after contraceptive discontinuation is therefore pivotal. Technical studies to date have evaluated return to fertility by assessing pregnancy as an outcome, with variable results, or return to ovulation as a surrogate measure by assessing hormone levels (such as progesterone, LH, FSH) with or without transvaginal ultrasound. In general, relying on time to pregnancy as an indicator of return to fertility following contraceptive method discontinuation can be problematic due to variable factors independent of contraceptive effects on fertility, hormone clearance, and fertility recovery. Since the ability to conceive after contraceptive method discontinuation is a critical factor influencing product uptake, it is important to have robust biomarkers that easily and accurately predict the timing of fertility return following contraception and isolate that recovery from extrinsic and circumstantial factors. The main aim of this review is to summarize the current approaches, existing knowledge, and gaps in methods of evaluating return-to-fertility as well as to provide insights into the potential of new biomarkers to more accurately predict fertility restoration after contraceptive discontinuation. Biomarker candidates proposed in this document include those associated with folliculogenesis, cumulus cell expansion, follicular rupture and ovulation, and endometrial transport and receptivity which have been selected and scored on predefined criteria meant to evaluate their probable viability for advancement. The review also describes limitations, regulatory requirements, and a potential path to clinically testing these selected biomarkers. It is important to understand fertility restoration after contraceptive method discontinuation to provide users and health providers with accurate evidence-based information. Predictive biomarkers, if easy and low-cost, have the potential to enable robust evaluation of RTF, and provide potential users the information they desire when selecting a contraceptive method. This could lead to expanded uptake and continuation of modern contraception and inform the development of new contraceptive methods to widen user's family planning choices.

The association between aldehydes exposure and female infertility: A cross-sectional study from NHANES

Environmental pollutants could be implicated in the cause of female infertility beyond traditional factors. Until now, no study has focused on the association of environmental exposure to aldehydes with female infertility. This study intended to investigate the possible impact of serum levels of aldehyde on female infertility. A cross-sectional study was performed on 516 nationally representative participants from 2013 to 2014 National Health and Nutrition Examination Survey (NHANES) in US. Multivariate logistic regression models and restricted cubic splines were used to examine the association between serum levels of aldehydes and the risk of female infertility. Women in the highest tertile of exposure to benzaldehyde had a 66% (odds ratio [OR] = 0.34, 95% confidence interval [CI] = 0.14-0.79) lower risk of infertility compared to those in the lowest tertile, after adjusting for other variables. Restricted cubic spline indicated a linear and negative association of benzaldehyde with female infertility (p for nonlinearity = 0.74), while other aldehydes did not exhibit a significant correlation. In summary, this cross-sectional study indicates that higher benzaldehyde level correlated with a lower rate of female infertility, which could help guide future research and contribute to the development of interventions to prevent or treat infertility and improve reproductive health outcomes.

Association of triclosan and human infertility: A systematic review

Triclosan (TCS) is a chemical compound, which has antibacterial, antiviral, and antifungal properties. TCS is considered an endocrine-disrupting chemical, which has been shown to interfere with developmental, behavioral, and reproductive outcomes in biological models and cell cultures. However, implications about exposure to TCS and human infertility are rare. Thus, the main of this review is summarize the available evidence of the association between triclosan exposure on human infertility. For this, systematic review was conducted following the recommendations established in Report of Systematic Reviews and Meta-Analyses guide (PRISMA). Initially, an electronic search in MEDLINE (via PubMed) and Science direct was performed. The methodological quality of the included studies was verified through the Joanna Briggs Institute (JBI) checklists. All selection and data extraction processes were carried out independently by two reviewers. The evidence was organized and presented using tables and narrative synthesis. There is lacking evidence about the association between triclosan and human infertility. Overall, no association between triclosan and infertility was found. However, semen quality and ovarian reserve are susceptible to triclosan exposure. Thus, future studies are still needed to better elucidate the associations between triclosan and infertility outcomes.

A robust multi-residue method for the monitoring of 25 endocrine disruptors at ultra-trace levels in surface waters by SPE-LC-MS/MS

Estrogenic endocrine disruptors are one of the biggest ecotoxicological threats in water that pose a significant ecological burden and health-risk for humans due to their high biological activity and proven additive effects. Therefore, we have developed and validated the most comprehensive and ultra-sensitive analytical method published to date, for reliable quantification of 25 high-risk endocrine disruptors at their ecologically relevant concentrations: naturally excreted hormones (estradiol, estrone, estriol, testosterone, corticosterone, and progesterone), synthetic hormones used for contraception and menopausal symptoms (ethinylestradiol, drospirenone, chlormadinone acetate, norgestrel, gestodene, tibolone, norethindrone, dienogest, and cyproterone) and bisphenols (BPS, BPA, BPF, BPE, BPAF, BPB, BPC, and BPZ). It is based on a solid-phase extraction of water samples, followed by a robust dansyl chloride derivatization with detection by liquid chromatography-tandem mass spectrometry with a single sample preparation and two analytical methods using the same analytical column and mobile phases. The achieved limits of quantitation are in the sub-ng L^-1 range, and detection limits as low as 0.02 ng L^-1, meeting the newest proposal for environmental quality standards (EQS) by the EU water framework directive for estradiol and ethinylestradiol. The method was extensively validated and applied to seven representative Slovenian water samples, where we detected 21 out of 25 analytes; 13 were quantified in at least one sample. Estrone and progesterone were quantified in all samples, reaching levels up to 50 ng L^-1; ethinylestradiol was higher than the current EQS (0.035 ng L^-1) in three samples, and estradiol was above its EQS (0.4 ng L^-1) in one sample, proving the method's applicability and the necessity for monitoring these pollutants.

Association between Organochlorine Pesticides and Vitamin D in Female Subjects

In human population studies, organochlorine pesticides (OCPs) have been linked to vitamin D deficiency. Therefore, this study examined the association between OCPs, vitamin D₃ (cholecalciferol, 25(OH)D₃), and the active metabolite 1,25-dihydrovitamin D₃ (1,25(OH)₂D₃) in a cohort of non-obese women. The serum samples of 58 female participants (age-31.9 ± 4.6 years; body mass index (BMI)-25.7 ± 3.7 kg/m²) were screened for 10 indicator OCPs. 25(OH)D₃ and 1,25(OH)₂D₃ levels were determined via isotope dilution liquid chromatography tandem mass spectrometry. In this cohort, the 25(OH)D₃ and 1,25(OH)₂D₃ levels were 22.9 ± 11.2 ng/mL and 0.05 ± 0.02 ng/mL, respectively, with 28 participants classified as 25(OH)D₃-deficient (<50 nmol/L). In the study cohort, no correlations were found between individual or total OCPs (ƩOCPs) and 25(OH)D₃. p,p'-dichlorodiphenyldichloroethylene (DDE) and ƩOCPs correlated positively with 1,25(OH)₂D₃, with the latter being negatively correlated with estimated glomerular filtration rate (eGFR). In women with sufficient 25(OH)D₃ levels, p,p'-dichlorodiphenyltrichloroethan (DDT) was positively correlated with 1,25(OH)₂D₃, whilst in the deficient group, hexachlorobenzene (HCB) and p,p'-(DDE) were positively correlated with 1,25(OH)₂D₃, β-Hexachlorocyclohexane (HCH) was positively correlated with 25(OH)D₃, and none of the OCPs were associated with measures of renal function. Overall, OCPs and ƩOCPs were not associated with 25(OH)D₃, suggesting that they are unrelated to vitamin D deficiency, but p,p'-DDE and ƩOCPs correlated positively with active 1,25(OH)₂D₃, while ƩOCPs correlated negatively with eGFR, suggesting a possible renal effect. Analysis of vitamin D deficiency revealed an association between β-HCH and 25(OH)D₃, and between HCB and p,p'-DDE and 1,25(OH)₂D₃, suggesting that OCP effects may be enhanced in cases of vitamin D deficiency.

Antioxidant Supplementation Alleviates Mercury-Induced Cytotoxicity and Restores the Implantation-Related Functions of Primary Human Endometrial Cells

Mercury (Hg) cytotoxicity, which is largely mediated through oxidative stress (OS), can be relieved with antioxidants. Thus, we aimed to study the effects of Hg alone or in combination with 5 nM N-Acetyl-L-cysteine (NAC) on the primary endometrial cells' viability and function. Primary human endometrial epithelial cells (hEnEC) and stromal cells (hEnSC) were isolated from 44 endometrial biopsies obtained from healthy donors. The viability of treated endometrial and JEG-3 trophoblast cells was evaluated via tetrazolium salt metabolism. Cell death and DNA integrity were quantified following annexin V and TUNEL staining, while the reactive oxygen species (ROS) levels were quantified following DCFDA staining. Decidualization was assessed through secreted prolactin and the insulin-like growth factor-binding protein 1 (IGFBP1) in cultured media. JEG-3 spheroids were co-cultured with the hEnEC and decidual hEnSC to assess trophoblast adhesion and outgrowth on the decidual stroma, respectively. Hg compromised cell viability and amplified ROS production in trophoblast and endometrial cells and exacerbated cell death and DNA damage in trophoblast cells, impairing trophoblast adhesion and outgrowth. NAC supplementation significantly restored cell viability, trophoblast adhesion, and outgrowth. As these effects were accompanied by the significant decline in ROS production, our findings originally describe how implantation-related endometrial cell functions are restored in Hg-treated primary human endometrial co-cultures by antioxidant supplementation.

Endocrine-Disrupting Chemicals and Persistent Organic Pollutants in Infant Formulas and Baby Food: Legislation and Risk Assessments

Human milk is the healthiest option for newborns, although, under specific circumstances, infant formula is a precious alternative for feeding the baby. Except for the nutritional content, infant formulas and baby food must be pollutant-free. Thus, their composition is controlled by continuous monitoring and regulated by establishing upper limits and guideline values for safe exposure. Legislation differs worldwide, although there are standard policies and strategies for protecting vulnerable infants. This work presents current regulations and directives for restricting endocrine-disrupting chemicals and persistent organic pollutants in infant formulas. Risk assessment studies, which are limited, are necessary to depict exposure variations and assess the health risks for infants from dietary exposure to pollutants.

Prenatal arsenic exposure, arsenic metabolism and neurocognitive development of 2-year-old children in low-arsenic areas

BACKGROUND

There is limited evidence on the effects of arsenic species and metabolic capacity on child neurodevelopment, particularly at low levels. Further, little is known about the critical window of exposure.

OBJECTIVE

To estimate the associations of arsenic exposure and arsenic metabolism in different pregnancy periods with neurodevelopment of two-year-old children.

METHODS

Concentrations of arsenobetaine (AsB), arsenite, arsenate, monomethyl arsenic acid (MMA), and dimethyl arsenic acid (DMA) in urine samples collected in three trimesters from 1006 mothers were measured using HPLC - ICPMS. Inorganic arsenic (iAs) was calculated as the sum of arsenite and arsenate. Total arsenic (tAs) was calculated as the sum of iAs, MMA and DMA. Child neurodevelopment was assessed with the Bayley Scales of Infant Development.

RESULTS

The geometric mean (GM) of SG-adjusted tAs in the first, second, third trimester was 16.37, 12.94, 13.04 μg/L, respectively. The mental development index (MDI) score was inversely associated with iAs and tAs. Compared to the 1st quartile, the MDI score decreased 0.43 (95%CI: -4.22, 3.36) for the 2nd, 6.50 (95%CI: -11.73, -1.27) for the 3rd, 5.42 (95%CI: -10.74, -0.10) for the 4th quartiles of iAs, and decreased 4.03 (95%CI: -7.90, -0.15) in the 4th quartile of tAs. In trimester-specific models, negative associations of DMA [-1.94 (95%CI: -3.18, -0.71)] and tAs [-1.61 (95%CI: -3.02, -0.20)] with the psychomotor development index (PDI) were only observed in 1st trimester.

CONCLUSIONS

Our study found inverse associations between prenatal arsenic exposure, especially in early pregnancy, and neurodevelopment of children at two years old, even at low exposure levels.

Physiological Benefits of Novel Selenium Delivery via Nanoparticles

Dietary selenium (Se) intake within the physiological range is critical to maintain various biological functions, including antioxidant defence, redox homeostasis, growth, reproduction, immunity, and thyroid hormone production. Chemical forms of dietary Se are diverse, including organic Se (selenomethionine, selenocysteine, and selenium-methyl-selenocysteine) and inorganic Se (selenate and selenite). Previous studies have largely investigated and compared the health impacts of dietary Se on agricultural stock and humans, where dietary Se has shown various benefits, including enhanced growth performance, immune functions, and nutritional quality of meats, with reduced oxidative stress and inflammation, and finally enhanced thyroid health and fertility in humans. The emergence of nanoparticles presents a novel and innovative technology. Notably, Se in the form of nanoparticles (SeNPs) has lower toxicity, higher bioavailability, lower excretion in animals, and is linked to more powerful and superior biological activities (at a comparable Se dose) than traditional chemical forms of dietary Se. As a result, the development of tailored SeNPs for their use in intensive agriculture and as candidate for therapeutic drugs for human pathologies is now being actively explored. This review highlights the biological impacts of SeNPs on growth and reproductive performances, their role in modulating heat and oxidative stress and inflammation and the varying modes of synthesis of SeNPs.

Networks of placental DNA methylation correlate with maternal serum PCB concentrations and child neurodevelopment

BACKGROUND

Gestational exposure to polychlorinated biphenyls (PCBs) has been associated with elevated risk for neurodevelopmental disorders. Placental epigenetics may serve as a potential mechanism of risk or marker of altered placental function. Prior studies have associated differential placental DNA methylation with maternal PCB exposure or with increased risk of autism spectrum disorder (ASD). However, sequencing-based placental methylomes have not previously been tested for simultaneous associations with maternal PCB levels and child neurodevelopmental outcomes.

OBJECTIVES

We aimed to identify placental DNA methylation patterns associated with maternal PCB levels and child neurodevelopmental outcomes in the high-risk ASD MARBLES cohort.

METHODS

We measured 209 PCB congeners in 104 maternal serum samples collected at delivery. We identified networks of DNA methylation from 147 placenta samples using the Comethyl R package, which performs weighted gene correlation network analysis for whole genome bisulfite sequencing data. We tested placental DNA methylation modules for association with maternal serum PCB levels, child neurodevelopment, and other participant traits.

RESULTS

PCBs 153 + 168, 170, 180 + 193, and 187 were detected in over 50% of maternal serum samples and were highly correlated with one another. Consistent with previous findings, maternal age was the strongest predictor of serum PCB levels, alongside year of sample collection, pre-pregnancy BMI, and polyunsaturated fatty acid levels. Twenty seven modules of placental DNA methylation were identified, including five which significantly correlated with one or more PCBs, and four which correlated with child neurodevelopment. Two modules associated with maternal PCB levels as well as child neurodevelopment, and mapped to CSMD1 and AUTS2, genes previously implicated in ASD and identified as differentially methylated regions in mouse brain and placenta following gestational PCB exposure.

CONCLUSIONS

Placental DNA co-methylation modules were associated with maternal PCBs and child neurodevelopment. Methylation of CSMD1 and AUTS2 could be markers of altered placental function and/or ASD risk following maternal PCB exposure.

Environmental phenol exposure associates with urine metabolome alteration in young Northeast Indian females

Urinary biomonitoring delivers the most accurate environmental phenols exposure assessment. However, environmental phenol exposure-related biomarkers are required to improve risk assessment to understand the internal processes perturbed, which may link exposure to specific health outcomes. This study aimed to investigate the association between environmental phenols exposure and the metabolome of young adult females from India. Urinary metabolomics was performed using liquid chromatography-mass spectrometry. Environmental phenols-related metabolic biomarkers were investigated by comparing the low and high exposure of environmental phenols. Seven potential biomarkers, namely histidine, cysteine-s-sulfate, 12-KETE, malonic acid, p-hydroxybenzoic acid, PE (36:2), and PS (36:0), were identified, revealing that environmental phenol exposure altered the metabolic pathways such as histidine metabolism, beta-Alanine metabolism, glycerophospholipid metabolism, and other pathways. This study also conceived an innovative strategy for the early prediction of diseases by combining urinary metabolomics with machine learning (ML) algorithms. The differential metabolites predictive accuracy by ML models was >80%. This is the first mass spectrometry-based metabolomics study on young adult females from India with environmental phenols exposure. The study is valuable in demonstrating multiple urine metabolic changes linked to environmental phenol exposure and a better understanding of the mechanisms behind environmental phenol-induced effects in young female adults.

Differences in personal care product use by race/ethnicity among women in California: implications for chemical exposures

BACKGROUND

Personal care products may contain many chemicals, some of which are suspected endocrine disrupters. This is an important source of chemical exposure for women, but little is known about how chemical exposure differs among different races/ethnicities.

OBJECTIVE

This study examines differences in personal care product use among Black, Latina, Vietnamese, Mixed Race, and White women in California.

METHODS

We used a community-based participatory process to create and administer a personal care product usage survey to 321 Black, Latina, Vietnamese, Mixed Race, and White women. We used multivariate regression models with pairwise comparisons to examine the frequency of product use by race/ethnicity.

RESULTS

We found distinct trends of personal care product use by race/ethnicity: Latina women typically used makeup most frequently; Black women used certain hair products or styles most frequently; and Vietnamese women were most likely to use facial cleansing products compared to other races/ethnicities. Latina and Vietnamese women were less likely to try to avoid certain ingredients in their products.

SIGNIFICANCE

These findings can help estimate disparities in chemical exposure from personal care product use and complement future research on health inequities due to chemical exposures in the larger environmental and social context.

Environmental factors affecting pregnancy outcomes

INTRODUCTION

Pregnancy represents a fragile period in the life of a woman, vulnerable to hazardous environmental substances which might affect maternal and fetal metabolism. The possible influence of environmental factors, including endocrine disrupting chemicals (EDCs), upon the mother and the fetus before and/or during pregnancy might be associated directly and/or indirectly to deleterious pregnancy outcomes. Because the existence of such associations would be, to our view, of major importance to the scientific community, their investigation is the scope of this critical review.

METHODS

This critical review includes in vivo animal and human studies regarding the role of environmental factors, including EDCs, on pregnancy outcomes complying with the SANRA (a scale for the quality assessment of narrative review articles) questions for narrative reviews. Studies were identified by searching the MEDLINE (PubMed and PubMed Central), the Cochrane library and the Google Scholar databases till October 2022 with the combinations of the appropriate key words (detailed environmental factors including EDCs AND detailed negative pregnancy outcomes) as well as by scanning references from already included articles and relevant reviews manually. Because environmental factors and EDCs have been associated to epigenetic alterations, special care has been given to EDC-induced transgenerational effects on pregnancy outcomes.

RESULTS

The existing evidence suggests positive associations between specific environmental factors and negative pregnancy outcomes such as ectopic pregnancies, pregnancy losses, gestational diabetes, hypertensive disorders of pregnancy, preterm births, birth defects, intrauterine growth restriction, and small or large for gestational age babies.

CONCLUSION

Environmental factors and EDCs may have a catalytic effect on the course and the outcomes of pregnancy.

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.

Reproductive toxicity of maternal exposure to di(2-ethylhexyl)phthalate and butyl paraben (alone or in association) on both male and female Wistar offspring

Parabens and phthalates are commonly found as contaminants in human fluids and are able to provoke reproductive toxicity, being considered endocrine disruptors. To evaluate the effects of phthalate and paraben, alone or in combination, on reproductive development of the offspring, female pregnant Wistar rats were allocated in six experimental groups: Three control groups (gavage [CG], subcutaneous [CS], and gavage + subcutaneous) received corn oil as vehicle, and the remaining groups were exposed to di(2-ethylhexyl)phthalate (DEHP) (500 mg/kg, gavage), butyl paraben (BP) (100 mg/kg, subcutaneously), or MIX (DEHP + BP), from Gestational Day 12 until Postnatal Day (PND) 21. The following parameters were assessed on the offspring: anogenital distance and weight at PND 1, nipple counting at PND 13, puberty onset, estrous cycle, weights of reproductive and detoxifying organs, histological evaluation of reproductive organs, and sperm evaluations (counts, morphology, and motility). Female pups from MIX group presented reduced body weight at PND 1, lower AGD, and decreased endometrium thickness. Male animals showed decreased body weight at PND 1 and lower number of Sertoli cells on DEHP and MIX groups, MIX group revealed increase of abnormal seminiferous tubules, DEHP animals presented delayed preputial separation and higher percentage of immotile sperms, and BP males presented diminished number of Leydig cells. In conclusion, the male offspring was more susceptible to DEHP toxicity; even when mixed to paraben, the main negative effects observed seem to be due to antiandrogenic phthalate action. On the other hand, DEHP seems to be necessary to improve the effects of BP on reducing estrogen-dependent and increasing androgen-dependent events.

Ovarian volume partially explains associations of phthalate biomarkers with anti-Müllerian hormone and estradiol in midlife women

BACKGROUND/OBJECTIVES

Women are ubiquitously exposed to endocrine disruptors, including phthalates. Ovarian follicles undergoing folliculogenesis (indirectly measured by ovarian volume) produce anti-Müllerian hormone (AMH) and estradiol (E2). We evaluated associations of phthalates with ovarian volume to assess whether this explained prior positive associations of phthalates with AMH and E2.

METHODS

Women ages 45-54 years (n = 614) had transvaginal ultrasounds of right/left ovaries to calculate mean ovarian volume. Women provided up-to-four urine and blood samples for quantifying AMH (first serum sample), E2 (all serum samples), and nine phthalate metabolites (from pooled urine, representing six parent phthalates). Multivariable linear or logistic regression models (for individual phthalate biomarkers), as well as weighted quantile sum (WQS) regression (for mixture analyses) evaluated associations of phthalate biomarkers with ovarian volume. Using cross-sectional mediation analysis, we assessed whether associations of phthalates with ovarian volume partially explained those of phthalates with AMH or E2.

RESULTS

Most women were non-Hispanic White (68%) and pre-menopausal (67%) with higher urinary phthalate metabolite concentrations than U.S. women. In single-pollutant models, 10% increases in mono(3-carboxypropyl) phthalate (MCPP) and monobenzyl phthalate (MBzP) were associated with 0.44% (95% CI: -0.02%, 0.91%) and 0.62% (95% CI: 0.02%, 1.23%) larger ovarian volumes, respectively. As a cumulative mixture, 10% increases in the phthalate mixture were associated with 2.89% larger ovarian volume (95%CI: 0.27, 5.59) with MCPP (35%) and MBzP (41%) identified as major contributors. Higher ovarian volume due to a 10% increase in MBzP (indirect effect OR: 1.004; 95% CI: 1.00, 1.01) explained 16% of the positive association between MBzP and higher AMH, whereas higher ovarian volume due to a 10% increase in MCPP (indirect effect %Δ: 0.11; 95% CI: -0.01, 0.22) explained 23% of the positive association between MCPP and E2.

CONCLUSION

In this cross-sectional study, phthalates were associated with increased ovarian volume, with implications for midlife hormone production.

A human-relevant mixture of endocrine disrupting chemicals induces changes in hippocampal DNA methylation correlating with hyperactive behavior in male mice

Humans are ubiquitously exposed to endocrine disrupting chemicals (EDCs), substances that interfere with endogenous hormonal signaling. Exposure during early development is of particular concern due to the programming role of hormones during this period. A previous epidemiological study has shown association between prenatal co-exposure to 8 EDCs (Mixture N1) and language delay in children, suggesting an effect of this mixture on neurodevelopment. Furthermore, in utero exposure to Mixture N1 altered gene expression and behavior in adult mice. In this study, we investigated whether epigenetic mechanisms could underlie the long term effects of Mixture N1 on gene expression and behavior. To this end, we analyzed DNA methylation at regulatory regions of genes whose expression was affected by Mixture N1 in the hippocampus of in utero exposed mice using bisulfite-pyrosequencing. We show that Mixture N1 decreases DNA methylation in males at three genes that are part of the hypothalamus-pituitary-adrenal (HPA) axis: Nr3c1, Nr3c2, and Crhr1, coding for the glucocorticoid receptor, the mineralocorticoid receptor, and the corticotropin releasing hormone receptor 1, respectively. Furthermore, we show that the decrease in Nr3c1 methylation correlates with increased gene expression, and that Nr3c1, Nr3c2, and Crhr1 methylation correlates with hyperactivity and reduction in social behavior. These findings indicate that an EDC mixture corresponding to a human exposure scenario induces epigenetic changes, and thus programming effects, on the HPA axis that are reflected in the behavioral phenotypes of the adult male offspring.

Current State of Sensors and Sensing Systems Utilized in Beer Analysis

Beer is one of the most consumed beverages in the world. Advances in instrumental techniques have allowed the analysis and characterization of a large number of beers. However, review studies that outline the methodologies used in beer characterization are scarce. Herein, a systematic review investigating the molecular targets and sensometric techniques in beer characterization was performed following the PRISMA protocol. The study reviewed 270 articles related to beer analysis in order to provide a comprehensive summary of the recent advances in beer analysis, including methods using sensors and sensing systems. The results revealed the use of various techniques that include several technologies, such as nanotechnology and electronics, often combined with scientific data analysis tools. To our knowledge, this study is the first of its kind and provides the reader with a faithful overview of what has been done in the sensor field regarding beer characterization.

Urinary phenol concentrations and fecundability and early pregnancy loss

STUDY QUESTION

Are urinary phenol concentrations of methylparaben, propylparaben, butylparaben, triclosan, benzophenone-3, 2,4-dichlorophenol or 2,5-dichlorophenol associated with fecundability and early pregnancy loss?

SUMMARY ANSWER

2,5-dichlorophenol concentrations were associated with an increased odds of early pregnancy loss, and higher concentrations of butylparaben and triclosan were associated with an increase in fecundability.

WHAT IS KNOWN ALREADY

Phenols are chemicals with endocrine-disrupting potential found in everyday products. Despite plausible mechanisms of phenol reproductive toxicity, there are inconsistent results across few epidemiologic studies examining phenol exposure and reproductive function in non-fertility treatment populations.

STUDY DESIGN, SIZE, DURATION

Specimens and data were from the North Carolina Early Pregnancy Study prospective cohort of 221 women attempting to conceive naturally from 1982 to 1986. This analysis includes data from 221 participants across 706 menstrual cycles, with 135 live births, 15 clinical miscarriages and 48 early pregnancy losses (before 42 days after the last menstrual period).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants collected daily first-morning urine specimens. For each menstrual cycle, aliquots from three daily specimens across the cycle were pooled within individuals and analyzed for phenol concentrations. To assess sample repeatability, we calculated intraclass correlation coefficients (ICCs) for each phenol. We evaluated associations between phenol concentrations from pooled samples and time to pregnancy using discrete-time logistic regression and generalized estimating equations (GEE), and early pregnancy loss using multivariable logistic regression and GEE.

MAIN RESULTS AND THE ROLE OF CHANCE

ICCs for within-person variability across menstrual cycles in pooled phenol concentrations ranged from 0.42 to 0.75. There was an increased odds of early pregnancy loss with 2,5-dichlorophenol concentrations although the CIs were wide (5th vs 1st quintile odds ratio (OR): 4.79; 95% CI: 1.06, 21.59). There was an increased per-cycle odds of conception at higher concentrations of butylparaben (OR: 1.62; 95% CI: 1.08, 2.44) and triclosan (OR: 1.49; 95% CI: 0.99, 2.26) compared to non-detectable concentrations. No associations were observed between these endpoints and concentrations of other phenols examined.

LIMITATIONS, REASONS FOR CAUTION

Limitations include the absence of phenol measurements for male partners and a limited sample size, especially for the outcome of early pregnancy loss, which reduced our power to detect associations.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to use repeated pooled measures to summarize phenol exposure and the first to investigate associations with fecundability and early pregnancy loss. Within-person phenol concentration variability underscores the importance of collecting repeated samples for future studies. Exposure misclassification could contribute to differences between the findings of this study and those of other studies, all of which used one urine sample to assess phenol exposure. This study also contributes to the limited literature probing potential associations between environmental exposures and early pregnancy loss, which is a challenging outcome to study as it typically occurs before a pregnancy is clinically recognized.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the National Institute of Environmental Health Sciences of the National Institutes of Health (award number F31ES030594), the Intramural Research Program of the National Institutes of Health, the National Institute of Environmental Health Sciences (project numbers ES103333 and ES103086) and a doctoral fellowship at the Yale School of Public Health. The authors declare they have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Polycystic Ovary Syndrome and Endocrine Disruptors (Bisphenols, Parabens, and Triclosan)-A Systematic Review

Exposure to endocrine disrupting chemicals (EDCs) can result in alterations of the female reproductive system, including polycystic ovary syndrome (PCOS). The aim of this review was to summarize the knowledge about the association of EDCs (bisphenols, parabens, and triclosan) with PCOS. We conducted an electronic literature search using PubMed for studies published between January 2007 and October 2022 on EDCs related to PCOS, and evaluated the association of PCOS with bisphenols, parabens and triclosan in 15 articles. Most studies revealed significantly higher plasma, urinary or follicular fluid levels of bisphenol A (BPA) in women with PCOS, and some showed a positive correlation of BPA with insulin resistance, polycystic morphology on ultrasound, hepatic steatosis, bilirubin levels, as well as free androgen index, androstenedione and testosterone serum levels, and markers of low-grade chronic inflammation. There was a negative correlation of BPA with markers of ovarian reserve, sex hormone binding globulin and vitamin D-binding protein. Parabens and triclosan have been studied in only one study each, with no significant associations with PCOS observed. Our review revealed an association of BPA with PCOS and negative effects of BPA on human ovaries; more research is needed to assess the potential associations of parabens and triclosan with PCOS.

Maternal exposure to di(2-ethylhexyl) phthalate (DEHP) causes multigenerational adverse effects on the uterus of F1 and F2 offspring rats

Phthalates are one of the ubiquitous chemicals found in day-to-day products like food packaging, children's toys, and other consumer commodities. There is rising concern that repeated exposure to phthalates during pregnancy and lactation could have long-term effects on maternal and fetal health. We hypothesize that exposure to DEHP during the developmental windows might affect the expression of molecules that regulate uterine function and that this effect would be passed on to further generations. Rat dams were treated with olive oil (vehicle) or DEHP (100 mg/kg b.wt./day) orally from gestational day 9 (GD 9) to the end of lactation (PND 21). F₀ maternal DEHP exposure resulted in multigenerational (F₁ and F₂) reproductive toxicity, as evidenced by an extended estrous cycle, decreased mating, fertility, and fecundity indices. Serum progesterone and estradiol levels were decreased and their cognate receptors (PR and ERα) in the uterus were decreased in the DEHP-exposed offspring rats. Further analysis of the expression of estrogen and progesterone regulatory genes such as Hox a11, VEGF A, Ihh, LIFR, EP4, PTCH, NR2F2, BMP2, and Wnt4 were reduced in the uteri of adult F₁ and F₂ generation rats born from DEHP-exposed F₀ dams. Decreased expression of these crucial proteins due to DEHP exposure may lead to defects in epithelial proliferation and secretion, uterine receptivity, and decidualization in the uteri of successive generations. This study showed that maternal DEHP exposure impairs the expression of molecules that regulate uterine function and this multigenerational effect is transmitted via maternal lineage.