Endocrine disruptors: Unravelling the link between chemical exposure and Women's reproductive health

Association between heavy metal exposure and pregnancy loss: evidence from NHANES 2011-2016

OBJECTIVE

Previous research suggests that heavy metal exposure may lead to pregnancy loss, but findings have varied. This study focuses on examining the relationship between heavy metal exposure (manganese, selenium, cadmium, lead, mercury) and pregnancy loss.

METHODS

Utilizing data from the 2011-2016 National Health and Nutrition Examination Survey (NHANES), this study included women between 20-80 years with complete pregnancy history, heavy metal exposure data, and covariate information. Pregnancy loss was self-reported by participants. Blood levels of manganese, selenium, cadmium, lead, and mercury were measured using mass spectrometry. Logistic regression, smooth curve fitting, and weighted quantile sum (WQS) regression were employed to investigate the association between heavy metal exposure and pregnancy loss. Subgroup analyses were conducted to verify the heterogeneity of the results.

RESULTS

A total of 3623 eligible women were included, with 1607 reporting pregnancy loss. Blood mercury levels were positively correlated with a higher risk of pregnancy loss (odds ratio 1.06, 95% confidence interval 1.03-1.09, P < 0.001), which remained significant in the two adjusted models. A nonlinear association between mercury levels and pregnancy loss was identified. The heterogeneity in this association was influenced by race, education level, body mass index, and age at menarche. No significant links were detected between pregnancy loss and cadmium, lead, manganese, and selenium. WQS regression highlighted the critical role of mercury in pregnancy loss.

CONCLUSION

Mercury exposure may contribute to a higher risk of pregnancy loss. Reducing heavy metal pollution and minimizing mercury exposure could potentially help improve pregnancy outcomes.

Suppression of human and rat 17β-hydroxysteroid dehydrogenase 1 by isothiazolinone-based disinfectants: Insights into mechanism and implications for hormonal homeostasis

Isothiazolinone disinfectants constitute a class of broad-spectrum antimicrobial agents due to the pandemic of COVID-19. The aim of this study was to assess the impacts of six distinct isothiazolinone disinfectants on the activity of 17β-hydroxysteroid dehydrogenase 1 (17β-HSD1) in humans and rats, as well as on BeWo cells. We identified IC50 with 4,5-dichloro-2-octyl-1,2-thiazol-3-one exhibiting the most potent inhibition (8.09 μM for human 17β-HSD1) and 5-chloro-2-methyl-1,2-thiazol-3-one showing the weak inhibition (81.94 μM for human 17β-HSD1) and these chemicals can potently inhibit estradiol production at ≥ 1 μM. Additionally, 4,5-dichloro-2-octyl-1,2-thiazol-3-one and 2-octyl-1,2-thiazol-3-one inhibited rat 17β-HSD1 at IC50 concentrations of 20.53 and 32.47 μM, respectively. Through mode action analyses, these compounds were found to exert mixed inhibition. Computational docking simulations revealed that isothiazolinone disinfectants interact with the NADPH binding domains of the two enzymes. Bivariate correlation analysis confirmed negative relationships between physicochemical properties such as LogP and heavy atoms, and half maximum inhibition concentrations of these chemicals. 3D-QSAR analysis revealed the presence of hydrophobic and hydrogen bond regions and both positively contribute to the binding. In conclusion, isothiazolinone disinfectants repress human and rat 17β-HSD1, depending on their hydrophobicity and hydrogen bonds.

In vitro to in vivo evidence for chemical disruption of glucocorticoid receptor signaling

Glucocorticoids are steroid hormones that regulate stress homeostasis, metabolism, and inflammatory responses. Dysregulation of the glucocorticoid receptor (GR) is linked to diseases such as obesity, mood disorders, and immune dysfunction. Endocrine-disrupting chemicals (EDCs) are widespread environmental contaminants known to interfere with hormone signaling, but their impact on glucocorticoid signaling remains unclear. While several GR-disrupting compounds have been identified in vitro, their in vivo effects remain largely unknown. In this study, we identified the agricultural agents dichlorodiphenyltrichloroethane (DDT) and ziram as GR-disruptors in vitro. In vivo, corticosterone co-treatment with DDT or the GR antagonist RU-486 inhibited the expression of classic GR-regulated transcripts in the liver. Furthermore, chronic exposure to DDT or RU-486 significantly reduced circulating B lymphocyte populations. These findings underscore the need to translate in vitro discoveries into in vivo models to assess the clinical relevance of GR-disrupting compounds. Moreover, they highlight the potential for xenobiotic-induced GR disruption to impair metabolic and immune homeostasis, potentially increasing disease susceptibility.

Multidisciplinary assessment of the impact of assisted reproductive techniques on pregnancy and long-term outcomes of mother and child: Foundation of the LE-REP (Leipzig Reproductive Health) Center

About 8-10 % of all people of reproductive age are unable to conceive children. In recent years, an increased number of consultations for fertility treatments has been observed with a continuing positive trend. It is known that infertility itself and assisted reproductive technologies (ARTs) are frequently associated with recurrent miscarriages, pregnancy complications or psychosocial problems. In parallel, metabolic and vascular diseases and obesity are becoming a growing issue, even among the younger population, and are affecting fertility and pregnancy outcomes of mother and child. Possible interactions between these conditions and the underlying mechanisms are not well understood hitherto. Furthermore, reproductive outcomes are increasingly challenged by the potential effects of environmental pollution on key reproductive processes, including oocyte maturation and atresia, sperm quality, implantation as well as their role in recurrent miscarriages. The Leipzig reproductive health (LE-REP) project is aimed at investigating the interplay between ARTs and the aforementioned reproductive challenges, including different aspects of fertility problems, early and late pregnancy as well as long-term effects on mothers and their children born via fertility treatment. This multidisciplinary initiative is expected to provide a deep understanding of underlying mechanisms, providing a framework for future preventive strategies improving reproductive health. Finally, LE-REP aims to establish a high-level university fertility center of excellence, combining advanced clinical care, cutting-edge research and education to train future reproductive medicine specialists.

Cytogenetic evaluation of vaginal and buccal epithelium of pregnant women living in conditions of radioactive, chemical and combined environmental contamination

INTRODUCTION

Many pollutants constantly worsen the ecological situation, thereby causing irreparable harm to the health of the population. Technogenic impact on the biosphere has become one of the significant factors dictating our conditions of existence on Earth.

PURPOSE OF THE STUDY

to conduct a comparative analysis of the frequency of cytogenetic abnormalities, indicators of proliferation disorders and nuclear destruction of vaginal and buccal epithelium of pregnant women 26-33 years old living in conditions of radioactive, chemical and combined environmental contamination of the Bryansk region.

METHODS

micronucleus test, staining method by Kvik, fluorescence method, immunocytochemistry method, Shapiro-Wilk test, Mann-Whitney U test.

RESULTS

the frequency of cytogenetic abnormalities, indicators of proliferation disorders and nuclear destruction in the vaginal epithelium of pregnant women living in areas of radioactive, chemical and combined environmental contamination is 1.3-4.9 times higher, and in the buccal epithelium 1.6-7.8 times higher compared to ecologically safe (control) areas (p < 0.01-0.001). The combined effect of radioactive contamination and chemical pollution resulted in a significantly higher (increase from 12.8% to 81.4% in vaginal epithelium and from 22.6% to 2.3 times in buccal epithelium) frequency of cells with micronuclei, cells with protrusions, binuclear cells, cells with double nuclei, as well as cells with karyopyknosis and karyolysis in pregnant women compared to areas with only one pollution factor.

CONCLUSION

The results demonstrate the synergistic effects of radiation contamination and chemical pollution on the cytogenetic status of pregnant women.

Mechanisms and rescue measures of female ovarian dysfunction induced by environmental endocrine chemicals: A review

Environmental endocrine chemicals (EDCs) constitute a class of exogenous chemicals with the capacity to imitate or impede the processes of synthesis, secretion, transport, conjugation, reaction, and metabolism of natural hormones in living organisms. They elicit a broad spectrum of physiological effects, which may either mirror those of natural hormones or exhibit anti-natural characteristics. Prolonged exposure to EDCs has been demonstrated to exert significant effects on animal reproduction and development. It is noteworthy that the female reproductive system is more susceptible to the effects of EDCs than the male reproductive system. EDCs have the potential to cause significant damage to the structure and function of the female reproductive organs, and have been linked to an increased incidence of various tumors in the female reproductive system, including ovarian cancer. A growing body of evidence suggests that exposure to EDCs affects reproduction in five main ways: competitively binding to cell membrane-specific receptors, disruption of cellular signaling within germ cells, intracellular imbalance between reactive oxygen species and antioxidants, alteration of epigenetic modifications, and control of early apoptosis. Nevertheless, the same in vivo and in vitro studies have indicated that the reproductive toxicity produced by EDCs can also be attenuated in a multitude of ways, such as by antioxidants, hormones, and compensatory mechanisms of signal transduction. Through comprehensive analysis of epidemiological studies, laboratory experiments, and clinical observations, this review details the mechanisms of the effects of EDCs leading to ovarian dysfunction and proposes a series of strategies to prevent EDCs exposure.

Shape-controlled asymmetric bowl-like PDA@Au substrates for sensitive SERS detection of anabolic androgenic steroids

The widespread accumulation of androgenic steroid endocrine disruptors in water and food has garnered increasing attention due to their significant risks to ecosystems and human health. These steroids, which cannot be completely eliminated, highlight the urgent need for advanced detection technologies. In this study, we present a novel emulsion-induced interface-anisotropic assembly strategy to synthesize bowl-like mesoporous polydopamine (PDA) particles, which exhibit high sensitivity in surface-enhanced Raman scattering (SERS) detection. In-situ reduction of chloroauric acid leads to the formation of Au nanoparticles (NPs) on the PDA surface, where synergistic Au-N interactions enhance the SERS performance. The distinctive bowl-like structure generates abundant "hot spots" on both sides, resulting in exceptional sensitivity. The low relative standard deviation (RSD) values (<11.7 %) across different PDA@Au NPs, along with real sample analyses (1.9-4.0 %), confirm the high reproducibility and uniformity of the SERS substrates, all achieved without the use of additional reducing agents. This cost-effective and straightforward method eliminates the need for complex surface treatments, making it particularly suitable for real-time detection of anabolic steroids across various matrices. These findings underscore the potential of bowl-like PDA materials for broader applications in clinical diagnostics, environmental monitoring, and sports doping control.

Impact of endocrine disruptors in cosmetics on reproductive function in males and females

The cosmetic and personal care product (PCP) industries have bloomed in the last ten years. Many new brand names have established themselves with various lucrative advertisements, luring youths into their primary customers. Many chemicals infused into daily day-night creams or shampoo conditioners have been established as Endocrine Disrupting Chemicals (EDC). The unseen side of the coin has been flipped in this article in an attempt to relate the rising infertility issue with these products. The study aims to explore the potential adverse effects and risk assessment of the EDCs of cosmetics and personal care products, which highlights a thorough review to indicate whether chemicals such as parabens, phthalates, or UV filters are safe for reproductive physiology. EDCs may cause severe negative impacts on the reproductive systems of both males and females which include reproductive problems such as polycystic ovarian syndrome, hypospadias, cryptorchidism, ovarian cancer, endometriosis, and poor sperm quality. Despite the widespread usage and purchase of cosmetic products in the present world, little research has been conducted on the possible effects of cosmetic EDCs on health. Consequently, further in-depth research needs to be performed in this field for a better understanding of the reproductive risks caused by cosmetic EDCs.

Molecular insights into the interaction mechanism of endocrine-disrupting chemicals and DNA in laccase-induced polymerization transfer

Endocrine-disrupting chemicals (EDCs), such as 17β-estradiol (E2) and bisphenol A (BPA), can induce DNA damage, leading to genomic instability and cell death. Laccase, an enzyme secreted by diverse organisms, plays a critical role in mitigating the cytotoxicity of these contaminants. Despite its importance, the dynamic evolution and interaction mechanisms of EDCs and DNA in laccase catalysis remain poorly understood. This study investigates the interactions between EDCs and DNA during laccase-induced polymerization transfer at a molecular level. As the DNA concentration was increased from 0 to 7.575 nM, the pseudo-first-order kinetic constants for E2 and BPA decreased by 2.03 and 2.10 times, respectively. DNA-bound EDCs disrupted the catalytic activity and stability of laccase, thereby delaying the polymerization transfer rate of EDCs. E2 and BPA bound to DNA base pairs via groove and intercalative modes, respectively. Laccase-induced polymerization reduced damage to the DNA helix and base stacking caused by EDC binding. Moreover, the resulting DNA-EDC-precipitated polymers, formed through continuous laccase polymerization, exhibited denser and more complex structures compared with spherical EDC-precipitated polymers, confirming DNA encapsulation and/or binding. This work underscores the intramolecular mechanisms of EDC interaction with DNA in vitro during the laccase-induced polymerization, offering efficient ways to mitigate the genotoxicity of EDCs.

Taurine alleviated acrylamide-induced ovarian toxicity via suppression of oxidative stress and apoptosis in mice

Acrylamide (Acr) poses reproductive toxicity risks to humans due to its ability to penetrate cell membranes and disrupt cellular balance. Taurine (Tau), a sulfur-containing amino acid with cell membrane stabilization and antioxidant properties, may mitigate these effects. This study examined how Tau can protect against oxidative stress and apoptosis induced by Acr in mouse ovarian tissue. Forty adult healthy mice, aged 6-8 weeks, were randomly assigned to four groups including the controls (received normal saline orally), Acr (50 mg/kg/day Acr orally), Acr + Tau75 (Acr and 75 mg/kg/day Tau), and Acr + Tau150 (Acr and 150 mg/kg/day Tau). Treatments were administered for 35 days, followed by assessments of stress markers and apoptosis via immunofluorescence and TUNEL assays. Both doses of Tau significantly increased the gene and protein expression levels of stress response enzymes, including Gpx1, Sod1, and Cat. Moreover, Tau significantly decreased the gene expression levels of apoptotic markers Caspase3 and Bax, while upregulating the antiapoptotic gene Bcl2l2. The TUNEL assay revealed the preventive properties of Tau against Acr-induced apoptosis in the ovaries. The current findings suggest the promising properties of Tau in the prevention of Acr-induced oxidative stress and apoptosis in mouse ovarian tissue. Therefore, Tau could play a protective role against Acr-induced reproductive toxicity in females, meriting further research into its potential applications.

Is air pollution a risk factor for early menopause?

BACKGROUND

Ambient air pollution is a serious public health issue that may influence reproductive health, including fertility and menopause onset in women worldwide. Thus, understanding the risk factors associated with early menopause is crucial to inform women about potential health risks and guide public health interventions.

METHODS

We collected data from KHANES (The Korea National Health and Nutrition Examination Survey) at the Korean Center for Disease Control and Prevention, Ministry of Health and Welfare between 2010 and 2020. These data were linked with summary pollution data from AiMS-CREATE (AI-Machine Learning and Statistics Collaborative Research Ensemble for Air Pollution, Temperature, and All Types of Environmental Exposures) from 2002 to 2020. These summary data encapsulate the monthly average air pollution predictions for 226 si-gun-gu (cities, counties, and districts) in Korea. A total of 8506 participants who had experienced menopause (early menopause: 40-44 years, N = 341; normal menopause: ≥ 45 years, N = 8165) between 2002 and 2020 were included in the analysis. We employed survey logistic regression analyses to determine the associations between ambient air pollution and menopause after adjusting for covariates.

RESULTS

An association was observed between particulate matter 2.5 (PM2.5) and early menopause (adjusted survey logistic regression (aOR): 1.26, 95% confidence interval (CI): 1.21-1.31), between particulate matter 10 (PM10) and early menopause (aOR: 1.17, 95% CI: 1.14-1.20).

CONCLUSION

Our findings suggest that exposure to ambient air pollution may contribute to the onset of menopause, emphasizing the importance of addressing air quality as a public health priority. This study highlights the need for further research to explore the underlying mechanisms and long-term health impacts of environmental factors associated with early menopause.

Urinary concentrations of phthalate metabolites and the survival of high-grade serous ovarian cancer with advanced stage

Phthalates have been reported to increase the risk of various hormone-dependent cancers. However, there is still a lack of evidence regarding the association between phthalates and overall survival (OS) in advanced high-grade serous ovarian cancer (HGSOC). This study investigated the relationship between urinary phthalate metabolites and OS in patients with HGSOC using a nested case-control study within the Ovarian Cancer Follow-Up Study. We matched 159 deceased patients with HGSOC to 159 survivors by age at diagnosis, body mass index, and sampling date. Spot urine samples were analyzed for ten phthalate metabolites and five classes of phthalate molar sums via mass spectrometry. Conditional logistic regression models were employed to calculate odds ratios (ORs) and 95% confidence intervals (CIs), comparing the highest tertile with the lowest. We found that the highest tertiles of mono-2-ethyl-5-oxohexyl phthalates and monoethyl phthalates were associated with poorer OS, with ORs (95%CIs) being 4.24 (1.46, 12.32) and 3.28 (1.16, 9.22), respectively. Additionally, the highest tertiles of the sum of di(2-ethylhexyl) phthalate metabolites, the sum of high-molar-weight phthalate metabolites, and the sum of 10 phthalate metabolites, were associated with worse OS, with ORs (95%CIs) were 18.4 (4.14, 81.87), 9.28 (2.87, 30.08), and 5.94 (2.00, 17.64), respectively. Our study suggests that exposure to high levels of phthalates may be associated with poorer OS in patients with advanced HGSOC, particularly exposure to di(2-ethylhexyl) phthalates. Since it is widely used in personal care products, avoiding the use of these products may improve the OS of patients with HGSOC.

Twenty-five years of research in endometriosis

Research rarely progresses in a straight line. It is more like an unpredictable front, marked by bursts of brilliance that fade after a few years, sudden breakthroughs, periods of stagnation, rediscoveries of forgotten ideas and occasional setbacks. Endometriosis research is no exception to these dynamics. In this opinion piece, three Generation X researchers who have been dedicated to endometriosis since the early days of their careers reflect on the field's progress over the past 25 years. Their verdict? Not disappointing. In fact, some pivotal strides have been made. The understanding of endometriosis has undergone a dramatic transformation. Hormonal therapies and assisted reproductive technology have emerged as first-line treatments, dethroning the once-central role of surgery. Non-invasive diagnosis of the disease has spread. This shift marks a notable evolution in how the disease is managed. However, high-throughput technologies have failed to deliver transformative insights, and the root causes of the disease remain as elusive as ever. Despite the setbacks, the progress made offers hope and direction.

Association between combined exposure to organochlorine pesticides and history of uterine fibroids in NHANES: findings from four statistical models

BACKGROUND

Organochlorine pesticides (OCPs) are extensively dispersed throughout the environment, which potentially have harmful impacts on the female reproductive system. Therefore, the purpose of this study was to clarify the association between exposure to OCPs and the history of uterine fibroids in American women.

METHODS

The present study comprised female individuals who were over 20 years old and were selected from the National Health and Nutrition Examination Survey (NHANES). The logistic regression models were used to investigate the associations between eight primary serum OCP compounds and uterine fibroids. The collective impact of OCP compounds on the overall association with uterine fibroids was assessed using three statistical approaches: weighted quantile sum regression (WQS), quantile g-computation model (Qgcomp), and Bayesian kernel machine regression (BKMR) model.

RESULTS

In the end, a total of 931 individuals were included in the analysis. Out of the total, 126 participants were identified as patients with uterine fibroids. Upon accounting for covariables, the logistic regression analysis revealed a positive association between the highest tertiles of OCP compounds and ln-transformed OCP compounds and the history of uterine fibroids. The analysis of WQS and Qgcomp showed that a 25% increase in the mixture of OCPs was associated with a higher likelihood of having a history of uterine fibroids, with odds ratios (ORs) of 1.49 (95% CI: 1.02, 2.19) and 1.64 (95% CI: 1.15, 2.35), respectively. The primary factor behind this association was oxychlordane. In addition, the overall findings of BKMR demonstrated a consistent and increasing pattern, indicating a robust positive association between the amount of serum OCP compounds and the history of uterine fibroid.

CONCLUSION

Our study conclusively established associations between OCPs and history of uterine fibroid. The simultaneous exposure to these chemicals is associated with an increased prevalence of uterine fibroid. Among these chemicals, oxychlordane has the most impact on the overall combined effect.

Novel Approach to Screen Endocrine-Disrupting Chemicals via Endocrine-Enhanced Reduced Human Transcriptome

Endocrine-disrupting chemicals (EDCs) can interfere with multiple pathways and trigger different modes of action. Thus, the traditional EDC in vitro screening processes often require a battery of bioassays to cover multiple target pathways. Here we developed an endocrine-enhanced reduced human transcriptome (ERHT) focused on hormone receptor signaling induced by the EDCs regulating specific genes. ERHT was developed based on 1200 prioritized genes covering 110 endocrine-related biological pathways across eight potential adverse outcomes. The ability of this approach to identify EDCs was derived from machine learning of 1068 dose-dependent transcriptome profiles and enhanced by quantifying chemical-induced critical pathway responses, and thus, it demonstrated excellent classification performance (AUC = 0.84 ± 0.03) in internal cross-validation. We ultimately applied this approach to known EDCs and inactive substances to validate the reliability of this approach. Through external validation on 210 chemicals, the extrapolation accuracy exceeded 80%, demonstrating the outstanding practical performance of this approach. Meanwhile, the pathway responses induced by the same chemical were consistent with the experimental results reported by multiple sequencing platforms, highlighting the robustness of this approach. The above results demonstrate that this approach can provide novel insights for EDCs' high-throughput screening and comprehensive toxic mechanisms through biological pathways.

Novel Method for Simultaneously Untargeted Metabolome and Targeted Exposome Analysis in One Injection

Serum endogenous metabolites and coexisting exogenous compounds are closely related to human health. Metabolomics often uses high-resolution mass spectrometry (HRMS), but current exposomics studies typically rely on triple quadrupole tandem mass spectrometry due to lower concentrations in the body. As a result, metabolome-exposome-wide association studies (mEWAS) require a combination of untargeted metabolomics and several targeted exposomics methods to measure more exposures, leading to increased time and sample consumption. In this study, a novel method was proposed by leveraging the advantages of recently introduced Zeno MRMHR technology; it allows for the simultaneous acquisition of the metabolome in HRMS and the exposome in multiple reaction monitoring (MRM) modes in one injection. The signal responses for exogenous compounds in MRM were comparable to those of metabolites in HRMS. This method was rigorously validated, and all exogenous standards had relative standard deviations (RSDs) below 20% for intraday and interday repeatability. Over 90% of metabolic features exhibited RSDs below 20% in these assessments. The method also had a broad quantification range, with lower limits of quantification (LLOQ) from 0.1 to 25 ng/mL and higher limits of quantification (HLOQ) from 2.5 to 1000 ng/mL. This approach was demonstratively applied to a type 2 diabetes mellitus cohort to identify serum risk factors and study the metabolome-exposome association. To our knowledge, this study is the first implementation of a unified method for the simultaneous analysis of endogenous metabolites in the untargeted mode and 210 exogenous compounds in the targeted mode in one injection, offering a novel tool for mEWAS research.

Associations between phenol and paraben exposure and the risk of developing breast cancer in adult women: a cross-sectional study

Increasing evidence suggests that endocrine-disrupting chemicals (EDCs) have adverse effects on breast cancer (BC). The aim of this study was to assess the association between exposure to prevalent EDCs-phenols and parabens-and the risk of developing BC. Data on urinary bisphenol A (BPA), triclosan (TRS), benzophenone-3 (BP3), methyl paraben (MPB), ethyl paraben (EPB), propyl paraben (PPB), and butyl paraben (BUP) were obtained from the 2005-2014 National Health and Nutrition Examination Survey. A total of 4455 subjects were included in this cross-sectional study. The results from the weighted multivariable regression models indicated that exposure to elevated concentrations of TRS increased the risk of developing BC by 2.33 (Q2: 95% CI = 1.45-3.75, p < 0.001) and 1.94 times (Q3: 95% CI = 1.21-3.09, p = 0.006), respectively. The nonlinear association between TRS concentrations and the risk of developing BC was statistically significant (P nonlinear = 0.007), with the restricted cubic splines (RCS) curve exhibiting an inverted U shape. The association between TRS concentrations and the risk of developing BC was more pronounced among overweight individuals (BMI ≥ 25 kg/m2), those aged < 60 years, and white individuals. Weighted quantile sum (WQS) and Bayesian Kernel Machine Regression (BKMR) analysis revealed no significant overall association between mixtures of urinary phenol and paraben metabolites and BC risk. However, TRS exposure was the most influential, with higher TRS concentrations (both continuous and categorical) significantly associated with an increased BC risk, particularly in overweight individuals (BMI ≥ 25 kg/m2), those aged < 60 years, and white individuals.

Reproductive and Metabolic Health Following Exposure to Environmental Chemicals: Mechanistic Insights from Mammalian Models

The decline in human reproductive and metabolic health over the past 50 years is associated with exposure to complex mixtures of anthropogenic environmental chemicals (ECs). Real-life EC exposure has varied over time and differs across geographical locations. Health-related issues include declining sperm quality, advanced puberty onset, premature ovarian insufficiency, cancer, obesity, and metabolic syndrome. Prospective animal studies with individual and limited EC mixtures support these observations and provide a means to investigate underlying physiological and molecular mechanisms. The greatest impacts of EC exposure are through programming of the developing embryo and/or fetus, with additional placental effects reported in eutherian mammals. Single-chemical effects and mechanistic studies, including transgenerational epigenetic inheritance, have been undertaken in rodents. Important translational models of human exposure are provided by companion animals, due to a shared environment, and sheep exposed to anthropogenic chemical mixtures present in pastures treated with sewage sludge (biosolids). Future animal research should prioritize EC mixtures that extend beyond a single developmental stage and/or generation. This would provide a more representative platform to investigate genetic and underlying mechanisms that explain sexually dimorphic and individual effects that could facilitate mitigation strategies.

Structure-activity relationship and in silico docking analysis of dicarboximide fungicides on 17β-hydroxysteroid dehydrogenase 1 of human, rat, and pig

Dicarboximide fungicides, including captafol, captan, cyclohexylthiophthalimide, folpet, and procymidone, represent a distinct category of fungicides. 17β-Hydroxysteroid dehydrogenase 1 (17β-HSD1) catalyzes the conversion of estrone to estradiol in mammals. Yet, the impact of these fungicides on 17β-HSD1 activity remains unknown. In this study, we investigated their inhibition using human placental cytosols, rat and pig ovarian cytosols. Our observations revealed that dicarboximide fungicides significantly inhibited human 17β-HSD1 activity. Among them, captan showed the strongest potency, with its IC50 of 1.28 μM, whereas procymidone had an IC50 of 100.71 μM. However, both rat and pig 17β-HSD1 enzymes were less sensitive to the inhibition of these fungicides compared to the human enzyme, with captan displaying an IC50 of 5.65 μM for the rat enzyme and 7.36 μM for the pig enzyme. Correlation analysis indicated a positive correlation between IC50 values and LogP. Docking analysis revealed that these fungicides bound to cofactor or between the steroid and cofactor binding sites. The dithiothreitol treatment demonstrated that the formation of irreversible bonds between dicarboximide fungicides and the cysteine residues played a key role in the inhibition of 17β-HSD1 activity. In conclusion, dicarboximide fungicides inhibit 17β-HSD1 depending on lipophilicity, species, and cysteine residue interactions.

Effects of parabens on human and rat placental 3β-hydroxysteroid dehydrogenase isoforms: Structure activity relationship and docking analysis

Parabens are widely used as preservatives in personal care products and are linked to potential disruptions in placental steroidogenesis. However, their exact impact remains unclear. This study aimed to explore the inhibition, mechanisms, structure-activity relationships (SAR) of parabens on human placental 3β-hydroxysteroid dehydrogenase type 1 (h3β-HSD1) and its rat counterpart, r3β-HSD4.3β-HSD activity was assayed in placental microsomes using pregnenolone as substrate and HPLC-MS/MS to measure progesterone and the effects of parabens on 3β-HSD was evaluated and SAR was performed. The research identified their inhibition against h3β-HSD1, with nonylparaben showing the highest potency (IC50, 4.17 µM), followed by phenylparaben, heptylparaben, hexylparaben, benzylparaben, butylparaben, propylparaben, and ethylparaben. The inhibition was characterized as mixed/noncompetitive. Additionally, these parabens inhibited progesterone secretion in human JAr cells at ≤100 µM. Similar trends were observed for r3β-HSD4. Docking simulations indicated that parabens interact with NAD+ and steroid-binding sites of both enzymes. A negative correlation between LogP, molecular weight, volume, and alcohol chain carbon with IC50 values highlighted the role of carbon chain length in determining inhibitory efficacy. The inhibitory potency of parabens on 3β-HSD is significantly influenced by their structural attributes, particularly the length of their carbon chains and LogP values.

In Vitro Toxicity of a DEHP and Cadmium Mixture on Sheep Cumulus-Oocyte Complexes

Di-(2-ethylhexyl) phthalate (DEHP) and Cadmium (Cd) affect female reproduction. To date, toxicological research has focused on the effects of individual contaminants, whereas living beings are exposed to mixtures. This study analyzed the effects of a DEHP/Cd mixture on nuclear and cytoplasmic maturation of sheep cumulus-oocyte complexes (COCs) compared with single compounds. COCs recovered from slaughterhouses-derived sheep ovaries were in vitro exposed to 0.5 μM DEHP, 0.1 μM Cd, or DEHP/Cd mixture at the same concentrations during 24 h of in vitro maturation (IVM). After IVM, oocyte nuclear chromatin configuration was evaluated, and bioenergetic/oxidative parameters were assessed on expanded cumulus cells (CCs) and matured oocytes (chi-square test and one-way ANOVA; p < 0.05). Under examined conditions, oocyte nuclear maturation was never impaired. However, COC bioenergetics was affected with stronger effects for the mixture than single compounds. Indeed, the percentages of matured oocytes with healthy mitochondrial distribution patterns were reduced (p < 0.001 and p < 0.05 for mixture and single compounds, respectively). Oocyte mitochondrial membrane potential, intracellular ROS levels, and mitochondria/ROS co-localization were reduced, with the same significance level, in all contaminated conditions. CCs displayed increased ROS levels only upon mixture exposure (p < 0.001). In conclusion, in vitro exposure to the DEHP/Cd mixture affected COC quality in the sheep to a greater extent than separate compounds.

Environmentally-relevant doses of bisphenol A and S exposure in utero disrupt germ cell programming across generations resolved by single nucleus multi-omics

Background

Exposure to endocrine-disrupting chemicals (EDCs), such as bisphenol A (BPA), disrupts reproduction across generations. Germ cell epigenetic alterations are proposed to bridge transgenerational reproductive defects resulting from EDCs. Previously, we have shown that prenatal exposure to environmentally relevant doses of BPA or its substitute, BPS, caused transgenerationally maintained reproductive impairments associated with neonatal spermatogonial epigenetic changes in male mice. While epigenetic alterations in germ cells can lead to transgenerational phenotypic variations, the mechanisms sustaining these changes across generations remain unclear.

Objectives

This study aimed to systematically elucidate the mechanism of transgenerational inherence by prenatal BPA and BPS exposure in the murine germline from F1 to F3 generations at both transcriptomic and epigenetic levels.

Methods

BPA or BPS with doses of 0 (vehicle control), 0.5, 50, or 1000 μg/kg/b.w./day was orally administered to pregnant CD-1 females (F0) from gestational day 7 to birth. Sperm counts and motility were examined in F1, F2, and F3 adult males. THY1+ germ cells on postnatal day 6 from F1, F2, and F3 males at a dose of 50 μg/kg/b.w./day were used for analysis by single-nucleus (sn) multi-omics (paired snRNA-seq and snATAC-seq on the same nucleus).

Results

Prenatal exposure to BPA and BPS with 0.5, 50, and 1000 μg/kg/b.w./day reduced sperm counts in mice across F1 to F3 generations. In the F1 neonatal germ cells, ancestral BPA or BPS exposure with 50 μg/kg/b.w./day resulted in increased differentially expressed genes (DEGs) associated with spermatogonial differentiation. It also disrupted the balance between maintaining the undifferentiated and differentiating spermatogonial populations. Differentially accessible peaks (DAPs) by snATAC-seq were primarily located in the promoter regions, with elevated activity of key transcription factors, including SP1, SP4, and DMRT1. Throughout F1-F3 generations, biological processes related to mitosis/meiosis and metabolic pathways were substantially up-regulated in BPA- or BPS-exposed groups. While the quantities of DEGs and DAPs were similar in F1 and F2 spermatogonia, with both showing a significant reduction in F3. Notably, approximately 80% of DAPs in F1 and F2 spermatogonia overlapped with histone post-translational modifications linked to transcription activation, such as H3K4me1/2/3 and H3K27ac. Although BPA exerted more potent effects on gene expression in F1 spermatogonia, BPS induced longer-lasting effects on spermatogonial differentiation across F1 to F3 males. Interestingly, DMRT1 motif activity was persistently elevated across all three generations following ancestral BPA or BPS exposure.

Discussion

Our work provides the first systematic analyses for understanding the transgenerational dynamics of gene expression and chromatin landscape following prenatal exposure to BPA or BPS in neonatal spermatogonia. These results suggest that prenatal exposure to environmentally relevant doses of BPA or BPS alters chromatin accessibility and transcription factor motif activities, consequently contributing to disrupted transcriptional levels in neonatal germ cells, and some are sustained to F3 generations, ultimately leading to the reduction of sperm counts in adults.

Awareness and Knowledge of Endocrine-Disrupting Chemicals Among Pregnant Women and New Mothers: A Cross-Sectional Survey Study

BACKGROUND/OBJECTIVES

Endocrine-disrupting chemicals (EDCs) are exogenous substances that interfere with hormone regulation, leading to adverse health outcomes. Despite the wide use of EDCs in daily products like plastics, personal care items, and food packaging, public awareness remains low. Pregnant women and new mothers are particularly vulnerable, as exposure to EDCs during early life stages can have long-term health impacts. This cross-sectional, questionnaire-based study aimed to assess the awareness of EDCs among pregnant women and new mothers at a maternity hospital.

METHODS

This cross-sectional study was conducted in a tertiary care hospital between January and August 2022. A questionnaire based on the Mutualités Libres/AIM 2020 survey was used to assess awareness of EDCs among pregnant and postpartum women. The original survey was adapted culturally and linguistically for the Turkish population through translation and expert review. The questionnaire included sections on sociodemographics, habits, knowledge, information sources, healthcare, readiness for change, expectations, and attitudes.

RESULTS

The results showed that 59.2% of participants were unfamiliar with EDCs, and many lacked awareness of the associated health risks, including cancers, infertility, and developmental disorders in children. A significant portion of respondents had never heard of bisphenol A (BPA) or phthalates, while awareness of parabens was relatively higher.

CONCLUSIONS

The study concluded that increasing awareness of EDCs is essential for fostering informed avoidance behaviors, especially in vulnerable populations like pregnant women and new mothers. Public health campaigns and healthcare provider involvement are crucial for enhancing awareness and reducing the health risks associated with EDCs.

Paraben preservatives exhibit inhibition on human and rat steroid 5α-reductase 1: A comprehensive 3D-QSAR and computational analysis

Parabens are preservatives used in personal care products, cosmetics, and pharmaceuticals. Steroid 5α-reductase 1 (SRD5A1) catalyzes the conversion of testosterone to dihydrotestosterone and is present in the brain, contributing to neurosteroid production. This study aimed to assess the effects of nine paraben preservatives on SRD5A1 in human SF126 glioblastoma cell and rat brain microsomes, particularly focusing on dihydrotestosterone production in SF126 cells. The results showed that methyl, ethyl, propyl, butyl, hexyl, heptyl, nonyl, phenyl, and benzyl paraben inhibited human SRD5A1, with nonylparaben having the strongest effect (7.59 μM). Additionally, kinetic analysis indicated that parabens acted as mixed/noncompetitive inhibitors, leading to a significant decrease in dihydrotestosterone production in SF126 cells. While rat SRD5A1 exhibited lower sensitivity to parabens, docking analysis revealed that parabens bind to the NADPH-binding site of both human and rat SRD5A1. In conclusion, these results highlight the inhibitory effects of paraben preservatives on SRD5A1 and elucidate their binding mechanisms, underscoring their role in hormone production.

Altered mitochondrial homeostasis on bisphenol-A exposure and its association in developing polycystic ovary syndrome: A comprehensive review

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy that is known to be one of the most common reproductive pathologies observed in premenopausal women around the globe and is particularly complex as it affects various endocrine and reproductive metabolic pathways. Endocrine-disrupting chemicals (EDCs) are considered to be environmental toxicants as they have hazardous health effects on the functioning of the human endocrine system. Among various classes of EDCs, bisphenol A (BPA) has been under meticulous investigation due to its ability to alter the endocrine processes. As there is emerging evidence suggesting that BPA-induced mitochondrial homeostasis dysfunction in various pathophysiological conditions, this review aims to provide a detailed review of how various pathways associated with ovarian mitochondrial homeostasis are impaired on BPA exposure and its mirroring effects on the PCOS phenotype. BPA exposure might cause significant damage to the mitochondrial morphology and functions through the generation of reactive oxygen species (ROS) and simultaneously downregulates the total antioxidant capacity, thereby leading to oxidative stress. BPA disrupts the mitochondrial dynamics in human cells by altering the expressions of mitochondrial fission and fusion genes, increases the senescence marker proteins, along with significant alterations in the mTOR/AMPK pathway, upregulates the expression of autophagy mediating factors, and downregulates the autophagic suppressor. Furthermore, an increase in apoptosis of the ovarian granulosa cells indicates impaired folliculogenesis. As all these key features are associated with the pathogenesis of PCOS, this review can provide a better insight into the possible associations between BPA-induced dysregulation of mitochondrial homeostasis and PCOS.

Evaluation of the Effects of Di-(2-ethylhexyl) phthalate (DEHP) on Caenorhabditis elegans Survival and Fertility

Di-2-ethylhexyl (DEHP), which is widely used in industrial products, is produced annually in excess of 2 million tons worldwide. DEHP is an endocrine disruptor and one of the major environmental pollutant chemicals (EDCs) in nature. There is some information about the effects of these products, which provide great advantages in every respect, on human health and the environment. In this study, C. elegans organism was used to evaluate the health and environmental risks of DEHP. The survival and fertility effects of DEHP on the C. elegans organism were examined and the results were evaluated. In the study, it was determined that DEHP not only shortened the survival time of C. elegans but also caused a decrease in fertility. DEHP (0.625 mM and 10 mM) caused a 23.2-30.6% decrease in fertility. Additionally, the LC50 (50% lethal concentration) value of DEHP was found to be 321 µg/mL.

The impact of Bisphenol-A on human reproductive health

Bisphenol-A (BPA) is a recognized endocrine-disrupting chemical used to produce several consumer goods and products. There has been widespread exposure to BPA because of increased industrial production and use of BPA-containing products. As a result of these exposures, BPA is found in several human body fluids and can cause endocrine disruption by interfering with hormone signaling pathways and epigenetic modifications. Therefore, human reproductive health and development have been adversely affected by BPA. This review aimed to consolidate existing knowledge on the impact of BPA on human reproductive health, examining its effects on both males and females. To achieve this, we systematically searched four databases for studies that associated BPA with reproductive health (male and female), after which we retrieved the important information from the selected articles. There was an association of reproductive health diseases with high BPA exposure. In males, BPA was associated with increased sperm alterations, altered reproductive hormone levels, and testicular atrophy. In females, there was an association of BPA exposure with hormonal imbalances, reduced ovarian reserve, and increased likelihood of conditions such as fibroids, polycystic ovarian syndrome, endometriosis and infertility. BPA's pervasive presence and its harmful effects on reproductive health underscore the need for global regulation and public awareness. Although substantial evidence from animal and in vitro studies supports the detrimental effects of BPA, there is a need for more human-focused research, particularly in developing countries, to confirm these findings. This review advocates for increased regulatory measures to limit BPA exposure.

Unlocking the roles of wheat root exudates in regulating laccase-catalyzed estrogen humification

While laccase humification has an efficient capacity to convert estrogenic pollutants, the roles of wheat (Triticum aestivum L.) root exudates (W-REs) in the enzymatic humification remain poorly understood. Herein, we presented the research into the effects of W-REs on 17β-estradiol (E2) and bisphenol A (BPA) conversion in vitro laccase humification. W-REs inhibited E2 removal but promoted BPA conversion in the enzymatic humification, and the first-order kinetic constants for E2 and BPA were 0.27-0.69 and 0.28-0.55 h-1, respectively. Specialized small phenols and amino acids in W-REs were susceptible to laccase humification, resulting in increased copolymerization of estrogen and W-REs. In greenhouse hydroponics, the accumulated amounts of E2 (BPA) in the roots and shoots were estimated to be 0.87 (2.15) and 0.43 (0.51) nmol·plant-1 at day 3, respectively. By forming low- and eventually non-toxic copolymeric precipitates between estrogen and W-REs, laccase humification lowered the phytotoxicity and bioavailability of estrogen in the rhizosphere solution, consequently relieving its uptake, accumulation, and distribution in the wheat cells. This work sheds light on the roles of W-REs in regulating laccase-catalyzed estrogen humification, and gives an insight into the path of addressing organic contamination in the rhizosphere and ensuring food safety.

Structural determinants of parabens in inhibiting human and rat gonadal 3β-hydroxysteroid dehydrogenase

This study delved into the impacts of 10 parabens on the activity of human and rat gonadal 3β-hydroxysteroid dehydrogenase (3β-HSD) within human KGN cell and rat testicular microsomes, as well as on the secretion of progesterone in KGN cells and the inhibitory potency was compared between human and rats. Intriguingly, the outcomes revealed that ethyl, propyl, butyl, hexyl, heptyl, nonyl, phenyl, and benzyl parabens displayed varying IC50 values for human 3β-HSD2, from 4.15 to 139.96 μM, demonstrating characteristics of mixed inhibitors. Notably, within KGN cells, all examined parabens, excluding nonyl and phenyl parabens, significantly inhibited progesterone secretion at 5-50 μM. In the case of rats, the IC50 values for these parabens on gonadal 3β-HSD1 fluctuated between 7.15 and 110.76 μM, likewise functioning as mixed inhibitors. Through docking analysis, it was proposed that most parabens effectively bind to NAD+ and/or steroid binding site. Moreover, bivariate correlation analysis unveiled an inverse correlation between IC50 values and structural characteristics such as LogP, molecular weight, heavy atom number, and carbon number within the alcohol moiety of parabens. 3D-QSAR elucidated pivotal regions, comprising hydrogen bond donor, hydrogen bond acceptor, and hydrophobic region, with the most potent inhibitor nonyl paraben engaging with all regions, while the weakest inhibitor ethyl paraben interacted with the regions except for the hydrophobic region. In conclusion, this investigation underscored the inhibitory effects imparted by several parabens on both human and rat gonadal 3β-HSD activity, with their inhibitory potency being modulated by aspects of hydrophobicity and carbon chain length.

Azoospermia and multi-organ damage in juvenile rats exposed to α-Terpineol from weaning to sexual maturity

This study aimed to evaluate the repeated oral administration of α-terpineol in juvenile Wistar rats over a 70-day period. The objective was to assess the potential systemic and reproductive toxicity of α-terpineol when administered by gavage at doses of 75, 150, and 300 mg/kg/day to juvenile Wistar rats for 70 days from postnatal day 24. The control group received corn oil for 70 days. During the study, various parameters were evaluated, including clinical signs, body weight, food intake, neurobehavioral observations, haematology, serum biochemistry, organ weights, steroidogenic gene expression, and histopathological examination. No toxicity-related changes were observed in body weight, food intake, neurobehavioral observations, or steroidogenic gene expression. However, sperm evaluation revealed a complete absence of sperm and delayed sexual maturation. Total cholesterol was significantly elevated in both sexes, and serum testosterone was reduced at the 150 and 300 mg/kg doses. Microscopic examination showed severe pathological changes in the testes, epididymis, liver, and kidneys of both males and females. After the 14-day recovery period, total cholesterol levels returned to the normal range, but no recovery was observed in the other organs. The no-observed-adverse-effect level was 75 mg/kg/day for male rats based on the histopathological findings in the testes, liver, and kidneys, and for female rats based on the kidney and liver histopathology.

Aromatase as a novel target of parabens in human and rat placentas: 3D-quantitative structure-activity relationship and docking analysis

Aromatase (CYP19A1), a pivotal enzyme in the biosynthesis of estradiol from testosterone, is predominantly expressed in reproductive tissues including placentas. This study investigated the effects of paraben acid and nine parabens on the activity of human and rat CYP19A1 using microsomes derived from human and rat placentas and on estradiol secretion in human choriocarcinoma BeWo cells. The results showed that propyl, butyl, hexyl, heptyl, and nonyl parabens significantly inhibited human CYP19A1 activity, with IC50 values of 66.37, 61.08, 55.65, 48.26, and 27.24 μM, respectively. In BeWo cells, these parabens notably diminished estradiol secretion at concentrations of 100 μM. Similarly, rat CYP19A1 was inhibited by these parabens, with IC50 values of 98.07, 70.10, 41.30, 27.93, and 6.33 μM for propyl, butyl, hexyl, heptyl, and nonyl parabens, respectively. Kinetic analysis identified these compounds as mixed inhibitors. Bivariate correlation analysis revealed a negative correlation between the partition coefficient value, molecular weight, the number of carbon atoms in the alcohol moiety, as well as heavy atom number and IC50 values. Three-dimensional quantitative structure-activity relationship analysis highlighted the critical role of hydrophobic regions in determining inhibitory potency. Docking studies suggested that parabens interact with the heme-iron binding site of both human and rat CYP19A1. This study elucidates the inhibitory effects of various parabens on CYP19A1 and their binding mechanisms, thereby providing a deeper understanding of their potential impact on estrogen biosynthesis.

The clinical, mechanistic, and social impacts of air pollution on atopic dermatitis

Atopic dermatitis (AD) is a complex disease characterized by dry, pruritic skin and significant atopic and psychological sequelae. Although AD has always been viewed as multifactorial, early research was dominated by overlapping genetic determinist views of either innate barrier defects leading to inflammation or innate inflammation eroding skin barrier function. Since 1970, however, the incidence of AD in the United States has increased at a pace that far exceeds genetic drift, thus suggesting a modern, environmental etiology. Another implicated factor is Staphylococcus aureus; however, a highly contagious microorganism is unlikely to be the primary etiology of a noncommunicable disease. Recently, the roles of the skin and gut microbiomes have received greater attention as potentially targetable drivers of AD. Here too, however, dysbiosis on a population scale would require induction by an environmental factor. In this review, we describe the evidence supporting the environmental hypothesis of AD etiology and detail the molecular mechanisms of each of the AD-relevant toxins. We also outline how a pollution-focused paradigm demands earnest engagement with environmental injustice if the field is to meaningfully address racial and geographic disparities. Identifying specific toxins and their mechanisms can also inform in-home and national mitigation strategies.

Impact of Bisphenol A exposure on maternal gut microbial homeostasis, placental function, and fetal development during pregnancy

Pregnancy is extremely vulnerable to external environmental influences. Bisphenol A, an endocrine-disrupting chemical, poses a significant environmental hazard to individuals of all ages and stages, particularly during pregnancy. The placenta is a temporary organ facilitating the connection between the mother and fetus. While it can detoxify certain exogenous substances, it is also vulnerable to the impacts of endocrine disruptors. Likewise, the intestinal flora is highly sensitive to exogenous stresses and environmental pollutants. The regulation of gut microbiota plays a crucial role in ensuring the health of both the mother and the fetus. The gut-placental axis connects the gut, gut microbes, placenta, and fetus. Exploring possible effects on placental function and fetal development involves analyzing changes in gut microbiota composition. Given that bisphenol A may cross the intestine and affect intestinal function, gut microorganisms, and their metabolites, as well as its potential impact on the placenta, resulting in impaired placental function and fetal development, this study aims to establish a link between bisphenol A exposure, intestinal microorganisms, placental function, and fetal development. This paper seeks to analyze the effects of maternal exposure to bisphenol A during pregnancy on the balance of the maternal gut microbiota, placental function, and fetal development, considering the key role of the gut-placental axis. Additionally, this paper proposes potential directions for future research emphasizing the importance of mitigating the adverse outcomes of bisphenol A exposure during pregnancy in both human and animal studies.

Origin, types, and contribution of emerging pollutants to environmental degradation and their remediation by physical and chemical techniques

The growing presence of emerging pollutants (EPs) in aquatic environments, as well as their harmful impacts on the biosphere and humans, has become a global concern. Recent developments and advancements in pharmaceuticals, agricultural practices, industrial activities, and human personal care substances have paved the way for drastic changes in EP concentrations and impacts on the ecosystem. As a result, it is critical to mitigate EP's harmful effects before they jeopardize the ecological equilibrium of the overall ecosystem and the sustainable existence of life on Earth. This review comprehensively documented the types, origins, and remediation strategies of EPs, and underscored the significance of this study in the current context. We briefly stated the major classification of EPs based on their organic and inorganic nature. Furthermore, this review systematically evaluates the occurrence of EPs due to the fast-changing ecological scenarios and their impact on human health. Recent studies have critically discussed the emerging physical and chemical processes for EP removal, highlighting the limitations of conventional remediation technologies. We reviewed and presented the challenges associated with EP remediation and degradation using several methods, including physical and chemical methods, with the application of recent technologies. The EP types and various methods discussed in this review help the researchers understand the nature of present-day EPs and utilize an efficient method of choice for EP removal and management in the future for sustainable life and development activities on the planet.

The Effect of Various Environmental Pollutants on the Reproductive Health in Children: A Brief Review of the Literature

PURPOSE OF REVIEW

Environmental pollutants in air, water, soil, and food are a significant concern due to their potential adverse effects on fetuses, newborns, babies, and children. These chemicals, which pass to fetuses and babies through trans-placental transfer, breast milk, infant formula, dermal transfer, and non-nutritive ingestion, can cause health problems during childhood. This review aims to discuss how exposure to various environmental pollutants in early life stages can disrupt reproductive health in children.

RECENT FINDINGS

Environmental pollutants can affect Leydig cell proliferation and differentiation, decreasing testosterone production throughout life. This may result in cryptorchidism, hypospadias, impaired semen parameters, and reduced fertility. Although many studies on female reproductive health cannot be interpreted to support causal relationships, exposure to pollutants during critical windows may subsequently induce female reproductive diseases, including early or delayed puberty, polycystic ovary syndrome, endometriosis, and cancers. There is growing evidence that fetal and early-life exposure to environmental pollutants could affect reproductive health in childhood. Although diet is thought to be the primary route by which humans are exposed to various pollutants, there are no adopted nutritional interventions to reduce the harmful effects of pollutants on children's health. Therefore, understanding the impact of environmental contaminants on various health outcomes may inform the design of future human nutritional studies.

Opportunities offered by latent-based multiblock strategies to integrate biomarkers of chemical exposure and biomarkers of effect in environmental health studies

Modern environmental epidemiology benefits from a new generation of technologies that enable comprehensive profiling of biomarkers, including environmental chemical exposure and omic datasets. The integration and analysis of large and structured datasets to identify functional associations is constrained by computational challenges that cannot be overcome using conventional regression methods. Some extensions of Partial Least Squares (PLS) regression have been developed to efficently integrate multiple datasets, including Multiblock PLS (MB-PLS) and Sequential and Orthogonalized PLS; however, these approaches remain seldom applied in environmental epidemiology. To address that research gap, this study aimed to assess and compare the applicability of PLS-based multiblock models in an observational case study, where biomarkers of exposure to environmental chemicals and endogenous biomarkers of effect were simultaneously integrated to highlight biological links related to a health outcome. The methods were compared with and without sparsity coupling two metrics to support the variable selection: Variable Importance in Projection (VIP) and Selectivity Ratio (SR). The framework was applied to a case-study dataset mimicking the structure of 36 environmental exposure biomarkers (E-block), 61 inflammation biomarkers (M-block), and their relationships with the gestational age at delivery of 161 mother-infant pairs. The results showed an overall consistency in the selected variables across models, although some specific selection patterns were identified. The block-scaled concatenation-based approaches (e.g. MB-PLS) tended to select more variables from the E-block, while these methods were unable to identify certain variables in the M-block. Overall, the number of variables selected using the SR criterion was higher than using the VIP criterion, with lower predictive performances. The multiblock models coupled to VIP, appeared to be the methods of choice for identifying relevant variables with similar statistical performances. Overall, the use of multiblock PLS-based methods appears to be a good strategy to efficiently support the variable selection process in modern environmental epidemiology.

Inhibitory effects of parabens on human and rat 17β-hydroxysteroid dehydrogenase 1: Mechanisms of action and impact on hormone synthesis

Parabens are commonly used preservatives in cosmetics, food, and pharmaceutical products. The objective of this study was to examine the effect of nine parabens on human and rat 17β-hydroxysteroid dehydrogenase 1 (17β-HSD1) in human placental and rat ovarian cytosols, as well as on estradiol synthesis in BeWo cells. The results showed that the IC50 values for these compounds varied from methylparaben with the weakest inhibition (106.42 μM) to hexylparaben with the strongest inhibition (2.05 μM) on human 17β-HSD1. Mode action analysis revealed that these compounds acted as mixed inhibitors. For rats, the IC50 values ranged from the weakest inhibition for methylparaben (no inhibition at 100 μM) to the most potent inhibition for hexylparaben (0.87 μM), and they functioned as mixed inhibitors. Docking analysis indicated that parabens bind to the region bridging the NADPH and steroid binding sites of human 17β-HSD1 and the NADPH binding site of rat 17β-HSD1. Bivariate correlation analysis demonstrated negative correlations between LogP, molecular weight, heavy atoms, and apolar desolvation energy, and the IC50 values of these compounds. In conclusion, this study identified the inhibitory effects of parabens and their binding mechanisms on human and rat 17β-HSD1, as well as their impact on hormone synthesis.

Per-polyfluoroalkyl substances (PFAS) as thyroid disruptors: is there evidence for multi-transgenerational effects?

INTRODUCTION

The environmental spread of pollutants has led to a persistent exposure of living beings to multiple chemicals, by now become ubiquitous in the surrounding environment. Environmental exposure to these substances has been reported to cause multi- and/or transgenerational health effects. Per- and Polyfluorinated Substances (PFAS) raise great concern, given their known effects both as endocrine disruptors and potential carcinogens. The multi/trans-generational effects of different endocrine disruptors have been investigated by several studies, and harmful effects observed also for PFAS.

AREAS COVERED

This review examines the current data on the multi-trans-generational effects of PFAS, with a focus on their impact on the thyroid axis. The aim is to determine if there is evidence of potential multi-trans-generational effects of PFAS on the thyroid and/or if more research is needed.

EXPERT OPINION

PFAS exposure impacts thyroid homeostasis and can cross the placental barrier. In addition PFAS have shown multi-transgenerational effects in laboratory experiences and animal models, but thyroid disruptive effects of PFAS were also investigated only in a small number of these studies. Efforts are needed to study the adverse effects of PFAS, as not all PFAS are regulated and removal strategies are still being developed.

The impact of indoor air pollution on children's health and well-being: the experts' consensus

BACKGROUND

Pollution of the indoor environment represents a concern for human health, mainly in case of prolonged exposure such as in the case of women, children, the elderly, and the chronically ill, who spend most of their time in closed environments.

MAIN BODY

The aim of the study is to organize a group of experts in order to evaluate the evidence and discuss the main risk factors concerning indoor air and the impact on human health as well as challenging factors regarding preventive strategies to reduce pollution. The experts highlighted the main risk factors concerning indoor air, including poor ventilation, climatic conditions, chemical substances, and socio-economic status. They discussed the impact on human health in terms of mortality and morbidity, as well as challenging factors regarding preventive strategies to reduce pollution.

CONCLUSION

The experts identified strategies that can be reinforced to reduce indoor pollution and prevent negative consequences on human health at national and local levels.

Bioprospecting photosynthetic microorganisms for the removal of endocrine disruptor compounds

Endocrine disruption compounds can be found in various daily products, like pesticides, along with cosmetic and pharmaceutical commodities. Moreover, occurrence of EDCs in the wastewater alarms the urgency for their removal before discharge owing to the harmful effect for the environment and human health. Compared to implementation of physical and chemical strategies, cultivation of photosynthetic microorganisms has been acknowledged for their high efficiency and eco-friendly process in EDCs removal along with accumulation of valuable byproducts. During the process, photosynthetic microorganisms remove EDCs via photodegradation, bio-adsorption, -accumulation, and -degradation. Regarding their high tolerance in extreme environment, photosynthetic microorganisms have high feasibility for implementation in wastewater treatment plant. However, several considerations are critical for their scaling up process. This review discussed the potency of EDCs removal by photosynthetic microorganisms and focused on the efficiency, mechanism, challenge, along with the prospect. Details on the mechanism's pathway, accumulation of valuable byproducts, and recent progress in scaling up and application in real wastewater were also projected in this review.

Exploring the Potential Link between PFAS Exposure and Endometrial Cancer: A Review of Environmental and Sociodemographic Factors

This exploratory narrative review paper delves into the intricate interplay between per- and polyfluoroalkyl substances (PFAS) exposure, sociodemographic factors, and the influence of stressors in the context of endometrial cancer. PFAS, ubiquitous environmental contaminants notorious for their persistence in the ecosystem, have garnered attention for their potential to disrupt endocrine systems and provoke immune responses. We comprehensively examine the various sources of PFAS exposure, encompassing household items, water, air, and soil, thus shedding light on the multifaceted routes through which individuals encounter these compounds. Furthermore, we explore the influence of sociodemographic factors, such as income, education, occupation, ethnicity/race, and geographical location and their relationship to endometrial cancer risk. We also investigated the role of stress on PFAS exposure and endometrial cancer risk. The results revealed a significant impact of sociodemographic factors on both PFAS levels and endometrial cancer risk. Stress emerged as a notable contributing factor influencing PFAS exposure and the development of endometrial cancer, further emphasizing the importance of stress management practices for overall well-being. By synthesizing evidence from diverse fields, this review underscores the need for interdisciplinary research and targeted interventions to comprehensively address the complex relationship between PFAS, sociodemographic factors, stressors, and endometrial cancer.

The Role of Endocrine Disruptors Bisphenols and Phthalates in Obesity: Current Evidence, Perspectives and Controversies

Excess body weight constitutes one of the major health challenges for societies and healthcare systems worldwide. Besides the type of diet, calorie intake and the lack of physical exercise, recent data have highlighted a possible association between endocrine-disrupting chemicals (EDCs), such as bisphenol A, phthalates and their analogs, and obesity. EDCs represent a heterogeneous group of chemicals that may influence the hormonal regulation of body mass and adipose tissue morphology. Based on the available data from mechanistic, animal and epidemiological studies including meta-analyses, the weight of evidence points towards the contribution of EDCs to the development of obesity, associated disorders and obesity-related adipose tissue dysfunction by (1) impacting adipogenesis; (2) modulating epigenetic pathways during development, enhancing susceptibility to obesity; (3) influencing neuroendocrine signals responsible for appetite and satiety; (4) promoting a proinflammatory milieu in adipose tissue and inducing a state of chronic subclinical inflammation; (5) dysregulating gut microbiome and immune homeostasis; and (6) inducing dysfunction in thermogenic adipose tissue. Critical periods of exposure to obesogenic EDCs are the prenatal, neonatal, pubertal and reproductive periods. Interestingly, EDCs even at low doses may promote epigenetic transgenerational inheritance of adult obesity in subsequent generations. The aim of this review is to summarize the available evidence on the role of obesogenic EDCs, specifically BPA and phthalate plasticizers, in the development of obesity, taking into account in vitro, animal and epidemiologic studies; discuss mechanisms linking EDCs to obesity; analyze the effects of EDCs on obesity in critical chronic periods of exposure; and present interesting perspectives, challenges and preventive measures in this research area.

Why Do We Study Aquatic Organisms?

Aquatic organisms comprising various plant and animal taxa represent a wide range of adaptations to a specific environment, but they also share many features with nonaquatic organisms of a given taxonomic group.[...].