Endocrine-disrupting chemicals: an Endocrine Society scientific statement

Protective effects of black ginseng on testicular toxicity induced by Di-n-butyl phthalate in rats

Di-n-butyl phthalate (DBP) is a phthalate-based material used as a plasticizer to soften polyvinyl chloride, and classified as an endocrine disruptor with antiandrogen effects. Exposure to DBP induces oxidative stress in rat testes, resulting in testicular toxicity. Black ginseng (BG) exhibits a higher antioxidant activity than white or red ginseng following repeated heat treatment and processing. This study aimed to investigate whether the antioxidant activity of BG might protect against DBP-induced testicular toxicity in juvenile Sprague-Dawley rats. A significant decrease in testicular weight was observed in most groups treated with DBP alone or in combination with BG. However, a significant testicular weight increase was detected after exposure to BG (10 ml/kg) + DBP (500 mg/kg). The epididymal weight was significantly reduced with associated histological changes including irregular arrangement, atrophy of seminiferous tubules and Sertoli cells, and Leydig cell damage following exposure to DBP alone as well as BG (2.5 ml/kg) + DBP (500 mg/kg). However, no marked changes were observed in the shape of seminiferous tubules in control and BG + DBP groups. A significant decrease in serum testosterone levels was found after exposure to DBP, but no marked alterations in the BG + DBP groups. Protein expression levels of nuclear factor erythroid-derived 2-related factor (Nrf2), NAD(P)H dehydrogenase 1 (NQO1), and, heme oxygenase-1; (HO-1) were significantly higher following DBP treatment, but lowered in the BG + DBP groups. Evidence indicates that BG exerts a protective effect against DBP-induced testicular toxicity in rats.

In-utero exposure to real-life environmental chemicals disrupts gene expression within the hypothalamo-pituitary-gonadal axis of prepubertal and adult rams

Environmental chemicals (ECs) have been associated with a broad range of disorders and diseases. Daily exposure to various ECs in the environment, or real-life exposure, has raised significant public health concerns. Utilizing the biosolids-treated pasture (BTP) sheep model, this study demonstrates that in-utero exposure to a real-life EC mixture disrupts hypothalamo-pituitary-gonadal (HPG) axis gene expression and reproductive traits in prepubertal (8-week-old, 8w) and adult (11-month-old) male sheep. Ewes were maintained on either BTP or pastures fertilized with inorganic fertilizer [control (C)] from approximately one month prior to insemination until around parturition. Thereafter, all animals were kept under control conditions. Effects on reproductive parameters including testosterone concentrations and the expression of key genes in the HPG axis were evaluated in eight-week-old and adult male offspring from both C and biosolids-exposed (B) groups. Results showed that, at 8w, relative to C (n = 11), B males (n = 11) had lower body weight, and altered testicular expression of HSD3B1, LHR and HSD17B3, BMP4, ABP, P27kip and CELF1. Principal component analysis (PCA) identified two 8w B subgroups, based on hypothalamic expression of GnRH, ESR1, and AR, and pituitary expression of KISSR. The two subgroups also exhibited different serum testosterone concentrations. The largest biosolids effects were observed in the hypothalamus of adult rams with NKB, ESR1, KISS1, AR, DLK1 and GNRH1 mRNA expression differing between B (n = 10) and C (n = 11) rams. Testicular steroidogenic enzymes CYP11A1 and HSD3B1 mRNA expression also differed between exposure groups. PCA identified two adult B subgroups, with BS1 (n = 6) displaying hypothalamic effects and BS2 (n = 4) both hypothalamic and testicular effects. The subgroups also differed in circulating testosterone concentrations. These findings demonstrate that exposure to a real-life EC mixture may predispose some males to infertility, by disrupting key functional HPG markers before puberty with consequent downstream effects on steroid hormones and spermatogenesis.

Transcriptomic characterization of 2D and 3D human induced pluripotent stem cell-based in vitro models as New Approach Methodologies for developmental neurotoxicity testing

The safety and developmental neurotoxicity (DNT) potential of chemicals remain critically understudied due to limitations of current in vivo testing guidelines, which are low throughput, resource-intensive, and hindered by species differences that limit their relevance to human health. To address these issues, robust New Approach Methodologies (NAMs) using deeply characterized cell models are essential. This study presents the comprehensive transcriptomic characterization of two advanced human-induced pluripotent stem cell (hiPSC)-derived models: a 2D adherent and a 3D neurosphere model of human neural progenitor cells (hiNPCs) differentiated up to 21 days. Using high-throughput RNA sequencing, we compared gene expression profiles of 2D and 3D models at three developmental stages (3, 14, and 21 days of differentiation). Both models exhibit maturation towards post-mitotic neurons, with the 3D model maturing faster and showing a higher prevalence of GABAergic neurons, while the 2D model is enriched with glutamatergic neurons. Both models demonstrate broad applicability domains, including excitatory and inhibitory neurons, astrocytes, and key endocrine and especially the understudied cholinergic receptors. Comparison with human fetal brain samples confirms their physiological relevance. This study provides novel in-depth applicability insights into the temporal and dimensional aspects of hiPSC-derived neural models for DNT testing. The complementary use of these two models is highlighted: the 2D model excels in synaptogenesis assessment, while the 3D model is particularly suited for neural network formation as observed as well in previous functional studies with these models. This research marks a significant advancement in developing human-relevant, high-throughput DNT assays for regulatory purposes.

The impact of endocrine-disrupting chemicals on stem cells: Mechanisms and implications for human health

Endocrine-disrupting chemicals (EDCs) are compounds, either natural or man-made, that interfere with the normal functioning of the endocrine system. There is increasing evidence that exposure to EDCs can have profound adverse effects on reproduction, metabolic disorders, neurological alterations, and increased risk of hormone-dependent cancer. Stem cells (SCs) are integral to these pathological processes, and it is therefore crucial to understand how EDCs may influence SC functionality. This review examines the literature on different types of EDCs and their effects on various types of SCs, including embryonic, adult, and cancer SCs. Possible molecular mechanisms through which EDCs may influence the phenotype of SCs are also evaluated. Finally, the possible implications of these effects on human health are discussed. The available literature demonstrates that EDCs can influence the biology of SCs in a variety of ways, including by altering hormonal pathways, DNA damage, epigenetic changes, reactive oxygen species production and alterations in the gene expression patterns. These disruptions may lead to a variety of cell fates and diseases later in adulthood including increased risk of endocrine disorders, obesity, infertility, reproductive abnormalities, and cancer. Therefore, the review emphasizes the importance of raising broader awareness regarding the intricate impact of EDCs on human health.

Bisphenol A leachate from polystyrene microplastics has species-specific impacts on scleractinian corals

Plastic waste causes pervasive environmental contamination and can result in the release of harmful chemical leachates into marine ecosystems, especially as they fragment to smaller microplastics (<5 mm). The toxicity of commonly found polystyrene (PS) microplastics and associated bisphenol A (BPA) leachate to framework-building corals Pocillopora damicornis and Dipsastraea pallida was assessed through exposure experiments. Intermittent exposure over 14-days to 1) virgin PS, 2) preformulated PS with bound BPA (BPA-PS) and 3) leached BPA-PS (L-BPA-PS; simulating early stages of weathering) showed that microplastics void of leachable BPA had minimal effect on either coral species. However, BPA leachate had negative effects on the maximal photochemical yield (Fv/Fm) and tissue composition of P. damicornis fragments (e.g., decreased chlorophyll and protein compared to controls). Conversely, BPA leachate did not compromise tissues of D. pallida fragments. These results reveal that exposure to chemicals leaching out of microplastics can drive negative effects of microplastic exposure distinct from physical mechanisms due to ingestion alone, and that effects are species specific.

Self-assembly of ZnO-Biochar/Kaolinite/Chitosan/GO with 1D/2D/3D heterojunctions for enhanced removal of estrogens and triclosan in water

This Study focuses on the preparation of sustainable and efficient Chitosan catalyst for the removal of three organic pollutants, 17β-Estradiol (E2), 17α-ethynyl estradiol (EE2) and triclosan (TCS) from water. The prepared nanocomposites were characterized by different techniques which confirmed the presence of the key components Chitosan, Carica Papaya seed and Kaolinite. The optical characterization proved the nanocomposite is photoactive with a band gap of 1.81 eV and 1.77 eV for Chitosan/kaolinite biochar (CS/KBC) and Chitosan/kaolinite biochar/GO (CS/KBC/GO) respectively, confirming the ability of the nanocomposite to be active in the visible light region of the spectrum. The degradation experiment using CS/KBC/GO was observed better with 100% removal for 5 mg/L E2 and EE2 over 60 min and 97.8% over 120 min for 10 mg/L TCS at optimum conditions (pH 3 for E2, and EE2 and pH 7). It was observed that the superoxide radical played a major role in the degradation of the contaminants. Furthermore, the CS/KBC/GO was efficient over four cycles without any decrease in performance, which rules out the question of catalyst deactivation proving the sustainability of the catalyst. The toxicity test shows that the water is safe as it does not harm cerio daphnia silvestrii organism.; CS/KBC/GO efficiently removed the micropollutants from real-life waste samples and the performance was very good with a slight decrease in performance for the wastewater due to the complex matrix of the water sample that competes for the active site.

Exploring the association between urinary bisphenol A, S, and F levels and semen quality parameters: Findings from Led-Fertyl cross-sectional study

Infertility is recognized as a multifaceted condition affecting approximately 15% of couples globally, influenced by various factors including genetic predisposition and environmental exposures. Among these environmental factors, bisphenol A (BPA) emerges as a prominent Endocrine-disrupting chemical (EDCs) widely distributed, leading to chronic human exposure in daily life. As regulations on BPA became more stringent, alternative substances such as bisphenol S (BPS) and bisphenol F (BPF) have emerged. Animal studies have demonstrated a dose-dependent decline in fertility and embryotoxicity following chronic exposure to BPA. However, literature data on human studies are limited and heterogeneous. Additionally, even less is known about the relationship between exposure to the BPA analogues (BPS and BPF) and sperm quality. Therefore, the present study aimed to examine the association between urinary concentrations of BPA, BPF, and BPS and semen quality parameters among 195 adult Spanish men from the Led-Fertyl study cohort using multiple linear regression models adjusted by potential confounding variables. Our results revealed an inverse association between log-transformed creatinine-adjusted concentration (ng/mg) of BPA and BPF levels and the percentage of sperm vitality (β: 3.56 %; 95%CI: 6.48 to -0.63 and β: 4.14 %; 95%CI: 6.97 to -1.31; respectively). Furthermore, participants in the highest quartile of BPA and BPF urinary concentration exhibited lower sperm vitality compared to those in the lowest quartile (β: 6.90 %; 95%CI: 11.60 to -2.15 and β: 9.68 %; 95%CI: 14.43 to -4.94; respectively). These results supply epidemiological evidence establishing a relationship between bisphenols urine exposure and sperm quality, suggesting that a re-evaluation of the overall safety of BPA alternatives is warranted.

The ENDOMIX perspective: how everyday chemical mixtures impact human health and reproduction by targeting the immune system†

Endocrine-disrupting chemicals are natural and synthetic compounds found ubiquitously in the environment that interfere with the hormonal-immune axis, potentially impacting human health and reproduction. Exposure to endocrine-disrupting chemicals has been associated with numerous health risks, such as neurodevelopmental disorders, metabolic syndrome, thyroid dysfunction, infertility, and cancers. Nevertheless, the current approach to establishing causality between these substances and disease outcomes has limitations. Epidemiological and experimental research on endocrine-disrupting chemicals faces challenges in accurately assessing chemical exposure and interpreting non-monotonic dose response curves. In addition, most studies have focused on single chemicals or simple mixtures, overlooking complex real-life exposures and mechanistic insights, in particular regarding endocrine-disrupting chemicals' impact on the immune system. The ENDOMIX project, funded by the EU's Horizon Health Program, addresses these challenges by integrating epidemiological, risk assessment, and immunotoxicology methodologies. This systemic approach comprises the triangulation of human cohort, in vitro, and in vivo data to determine the combined effects of chemical mixtures. The present review presents and discusses current literature regarding human reproduction in the context of immunotolerance and chemical disruption mode of action. It further underscores the ENDOMIX perspective to elucidate the impact of endocrine-disrupting chemicals on immune-reproductive health.

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.

Associations between per- and polyfluoroalkyl substances (PFAS) and female sexual function in a preconception cohort

BACKGROUND

Female sexual function is important for sexual well-being, general health, fertility, and relationship satisfaction. Distressing impairments in sexual function, clinically recognized as female sexual dysfunction (FSD), can manifest as issues with interest/desire, arousal, orgasm, and pain during vaginal penetration. Some evidence suggests that exposure to endocrine-disrupting chemicals may adversely affect female sexual function, but associations for per- and polyfluoroalkyl substances (PFAS) have not been previously evaluated.

OBJECTIVE

We investigated associations between serum PFAS concentrations and female sexual function among U.S. pregnancy planners.

METHODS

We used cross-sectional data from participants from Pregnancy Study Online (PRESTO), a prospective preconception cohort study. Participants reported sexual function and distress at baseline on two validated measures: a modified version of the Female Sexual Function Index-6 (FSFI-6) and the Female Sexual Distress Scale (FSDS). We quantified PFAS serum concentrations in samples collected in the preconception period (i.e., at baseline) using solid phase extraction-high performance liquid chromatography-isotope-dilution-mass spectrometry. Participants reported sociodemographic information on structured baseline questionnaires. We included 78 participants with complete PFAS and sexual function data and fit multivariable linear regression models to estimate mean differences in FSFI-6 scores (β) or percent differences (%) in FSDS scores per interquartile range (IQR) increase in PFAS concentrations, adjusting for age, annual household income, years of education, parity, and body mass index. We further investigated effect measure modification by parity (parous vs. nulliparous) in stratified models.

RESULTS

An IQR increase in perfluorohexanesulfonic acid was associated with a 1.0-point decrease (95% CI = -1.8, -0.1) in reported FSFI-6 scores, reflecting poorer sexual function. PFAS were consistently associated with lower FSFI-6 scores among parous participants. PFAS were also associated, though imprecisely, with greater sexual distress.

CONCLUSION

Some PFAS were associated with poorer sexual function among U.S. pregnancy planners, but future studies are needed to clarify the extent to which PFAS influences female sexual health.

In silico models for the screening of human transthyretin disruptors

The use of New Approach Methodologies (NAMs), such as Quantitative Structure-Activity Relationship (QSAR) models, is highly recommended by international regulations to speed up hazard and risk assessment of Endocrine Disruptors, which are known to be linked to a wide spectrum of severe diseases on humans and wildlife. A very sensitive target for these chemicals is the thyroid hormone system, which plays a key role in regulating metabolic and cognitive functions. Several chemicals have been demonstrated to compete with the thyroid hormone thyroxine (T4) for binding to human thyroid hormone distributor protein transthyretin (hTTR). In this work, we generated three new datasets composed by T4-hTTR competing potencies of more than 200 heterogeneous chemicals measured by three different in vitro assays. These datasets were used for the development of new regression QSAR models. The best models were thoroughly validated by internal and external validation procedures. The mechanistic interpretation of the selected molecular descriptors provided information on structural features which are relevant to characterise hTTR binders, such as the presence of hydroxylated and halogenated aromatic rings. PCA analysis was used to rank the studied chemicals according to their increasing T4-hTTR competing potency. Hydroxylated and halogenated bicyclic aromatic compounds are ranked as the strongest hTTR binders. The new QSARs are useful to screen potential Thyroid Hormone System-Disrupting Chemicals (THSDCs), and to support the identification of sustainable alternatives to hazardous chemicals.

Evaluation of the impact of environmental pollutants on the sex ratio: a systematic review

In several industrialized countries, there has been a report of a decrease in the proportion of male births. The current study is designed to perform a systematic review and present a comprehensive summary of current epidemiological evidence of an association between exposure to the mentioned pollutants and sex ratio. The present systematic review was executed according to the PRISMA protocol. A comprehensive online search was performed in PubMed Medline, Scopus, Web of Science, Embase databases, Google Scholar, and the World Health Organization databases from 2000 to September 2023. After searching all databases, 20 articles were included in this systematic review. Regarding the studied pollutants found that exposure to increased PM10, PM2.5, and Nitrogen dioxide (NO2) levels was significantly associated with the sex ratio. Both maternal Benzophenone (BP)-2 and paternal BP-2 were significantly associated with an excess of female births. Finally, it must be said that the effect of some environmental pollutants on the sex ratio is undeniable. However, the sex ratio is the result of multiple factors that interact simultaneously during pregnancy. Additional research is required to examine the mechanisms responsible for the change in sex ratio.

Interference Mechanisms of Endocrine System and Other Systems of Endocrine-Disrupting Chemicals in Cosmetics-In Vitro Studies

Endocrine-disrupting chemicals (EDCs), found in various cosmetic products, interfere with the normal functioning of the endocrine system, impacting hormone regulation and posing risks to human health. Common cosmetic EDCs, such as ultraviolet (UV) filters, parabens, and triclosan, can enter the human body through different routes, including skin absorption. Their presence has been linked to adverse effects on reproduction, immune function, and development. High-throughput in vitro assays, using various human cell lines, were employed to assess the effects of common cosmetic EDCs such as ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), homosalate, and parabens. Despite ongoing regulatory efforts, gaps persist in understanding their long-term impacts, particularly when they are present as mixtures or degradation products in the environment. This study focuses on recent in vitro research to investigate the mechanisms through which cosmetic-related EDCs disrupt the endocrine system and other physiological systems. The in vitro findings highlight the broader systemic impact of these chemicals, extending beyond the endocrine system to include immune, reproductive, and cardiovascular effects. This research underscores the importance of developing safer cosmetic formulations and enhancing public health protection, emphasizing the need for stricter regulations.

A prospective cohort study of persistent endocrine-disrupting chemicals and perceived stress

Persistent endocrine-disrupting chemicals (EDCs) can dysregulate the stress response. We evaluated associations between persistent EDCs and perceived stress among participants in the Study of Environment, Lifestyle, and Fibroids (n = 1394), a prospective cohort study of Black women. Participants completed the Perceived Stress Scale 4 (PSS-4) at baseline and every 20 months through 60 months (score range: 0-16); higher scores indicate higher stress. Endocrine-disrupting chemicals, including per- and polyfluoroalkyl substances, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides, were quantified in plasma samples at baseline. We fit bayesian kernel machine regression and linear mixed-effects models to estimate associations of EDCs (as a mixture and individually) with PSS-4 scores at baseline and at each follow-up visit, respectively. Increasing percentiles of the mixture were not strongly associated with PSS-4 scores at baseline, and no interactions were observed among EDCs. Several individual EDCs (eg, perfluorodecanoic acid, PCB 118, PBDE 99) were associated with higher PSS-4 scores at baseline or follow-up, and other EDCs (eg PCB 138/158) were associated with lower PSS-4 scores at baseline or follow-up. The directionality of associations for individual EDCs was inconsistent across follow-up visits. In conclusion, specific EDCs may be associated with perceived stress in Black women. This article is part of a Special Collection on Environmental Epidemiology.

Reproductive mechanisms, pathologies, and health inclusivity: insights from the 2023 Annual Meeting of the Society for Reproductive Biology

In 2023, the Society for Reproductive Biology met in Brisbane to deliver its largest scientific program to date. Herein, we detail key areas of notable discovery across the reproductive biology and fertility landscapes, as well as pressing areas that require further research. Specifically, we focus on five key themes: the cellular basis of reproduction; environmental impacts on reproduction; inclusivity in reproductive health; reproductive cancers; and evolution of reproduction mechanisms. Highlights included the utility of organism models, such as using fruit flies to model human genetic disease, and the development of new blastocyst models; the impact of elevated temperature and endocrine-disrupting chemicals on the germline, sex organ development, and fertility in mammals; how we can improve the inclusivity of transgender and Pacific Rainbow+ people in reproductive health; novel insights in reproductive cancer pathogenesis and inhibitor treatments; and the evolution of the sex chromosomes and sex determination across animals. The breadth of topics covered underscores the far-reaching impacts of reproduction and its related processes across life, health, and wellbeing, as well as for food production and the economy.

Biochemical study of the risk of diabetes, prediabetic and insulin resistance in car painters and its association with mercury exposure: a retrospective case-control study

Purpose

There is controversy about the effect of mercury (Hg) exposure on developing diabetes and insulin resistance. This study aimed to assess the risk of diabetes and insulin resistance in car painters using biochemical markers and serum Hg levels.

Methods

A retrospective case-control study involving 210 male participants aged between 25 and 50 years. The participants were divided into two groups: Car painters for at least one year and healthy people who had not worked as car painters and had no health concerns or chronic diseases.

Results

The serum levels of Hg, MDA (malondialdehyde), interleukin (IL)-1β, visfatin, fasting insulin, and fasting blood glucose (FBG) were evaluated. Serum Hg levels were significantly higher in car painters compared to the control group (19.00 ± 7.20 vs. 8.339 ± 3.916 μg/L, P-value < 0.001). Serum levels of visfatin, MDA, insulin, FBG, and IL-1β were significantly higher in the car painter compared to the control (P-value < 0.001). There was a significantly higher proportion of people with diabetes in car painters compared to control (8.6% vs. 0%) and higher prediabetic (30.5% vs. 13.3%, P-value < 0.001). In car painter workers, levels of Hg were significantly higher in DM compared to prediabetic and normoglycemic car painter workers (27.01 ± 1.59, 23.98 ± 4.31, and 15.39 ± 6.41 μg/mL, respectively, P-value < 0.001); additionally, levels of Hg were significantly higher car painter with insulin resistance compared to non-insulin resistance workers (21.18 ± 7.29 vs. 16.79 ± 16.7 μg/mL, P-value < 0.001).

Conclusions

Increased serum Hg in car painters increases the risk of insulin resistance and diabetes/prediabetes status.

Environmental triggers and future risk of developing autoimmune diseases: Molecular mechanism and network toxicology analysis of bisphenol A

Bisphenol A (BPA), a chemical compound in plastics and resins, widely exist in people's production and life which have great potential to damage human and animal health. It has been proved that BPA could affect human immune function and promote the occurrence and development of autoimmune diseases (ADs). However, the mechanism and pathophysiology remain unknown. Therefore, this study aims to advance network toxicology strategies to efficiently investigate the putative toxicity and underlying molecular mechanisms of environmental pollutants, focusing on ADs induced by BPA exposure. Leveraging databases including ChEMBL, STITCH, SwissTargetPrediction, GeneCards, and OMIM, we identified potential targets associated with BPA exposure and ADs, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis (MS), Hashimoto's thyroiditis (HT), inflammatory bowel disease (IBD), and type 1 diabetes (T1D). Subsequent refinement using STRING and Cytoscape software highlighted core targets respectively, and Metascape was utilized for enrichment analysis. Gene expression data from the GEO database revealed the upregulation or downregulation of these targets across these ADs. Molecular docking performed with Autodock confirmed robust binding between BPA and core targets, notably PPARG, CTNNB1, ESR1, EGFR, SRC, and CCND1. These findings suggest that BPA exposure may serve as an environmental trigger in the development of autoimmunity, underscoring potential environmental risk factors for the onset of autoimmune conditions.

Unravelling bisphenol A-induced hepatotoxicity: Insights into oxidative stress, inflammation, and energy dysregulation

Bisphenol A (BPA), a prevalent plastic monomer and endocrine disruptor, negatively impacts metabolic functions. This study examines the chronic effects of eco-relevant BPA concentrations on hepatotoxicity, focusing on redox balance, inflammatory response, cellular energy sensors, and metabolic homeostasis in male Swiss albino mice. Chronic BPA exposure resulted in reactive oxygen species (ROS) accumulation, altered hepatic antioxidant defense, lipid peroxidation, and NOX4 expression, leading to reduced cell viability. Additionally, BPA exposure significantly upregulated hepatic pro-inflammatory cytokine genes (Tnf-α, Il-1β, Il-6), NOS2, and arginase II, correlating with increased TLR4 expression, NF-κB phosphorylation, and a dose-dependent decrease in IκBα levels. BPA-induced NF-κB nuclear localization and inflammasome activation (NLRP3, cleaved caspase-1, IL-1β) established an inflammatory milieu. Perturbations in hepatic AMPKα phosphorylation, SIRT1, and PGC-1α, along with elevated p38 MAPK phosphorylation and ERα expression, indicated BPA-induced energy dysregulation. Furthermore, increased PLA2G4A, COX1, COX2, and PTGES2 expression in BPA-treated liver correlated with hyperlipidemia, hepatic FASN expression, steatosis, and visceral adiposity, likely due to disrupted energy sensors, oxidative stress, and inflammasome activation. Elevated liver enzymes (ALP, AST, ALT) and apoptotic markers indicated liver damage. Notably, N-acetylcysteine (NAC) priming reversed BPA-induced hepatocellular ROS accumulation, NF-κB-inflammasome activation, and intracellular lipid accumulation, while upregulating cellular energy sensors and attenuating ERα expression, suggesting NAC's protective effects against BPA-induced hepatotoxicity. Pharmacological inhibition of the NF-κB/NLRP3 cascade in BAY11-7082 pretreated, or NLRP3 immunodepleted hepatocytes reversed BPA's negative impact on SIRT1/p-AMPKα/PGC-1α and intracellular lipid accumulation, providing mechanistic insights into BPA-induced metabolic disruption.

Evaluation of Bisphenol S (BPS) toxicity on the reproductive system of Channa striatus: Insights for environmental risk assessment

Aquatic ecosystems face significant exposure to endocrine-disrupting chemicals (EDCs), which can mimic, block, or alter the synthesis of endogenous hormones. Bisphenol A (BPA), a widely known EDC, has been phased out from consumer products due to concerns about its potential impacts on human health. In its place, bisphenol S (BPS), an organic compound, has been increasingly used in the production of polycarbonate plastics, epoxy resins, thermal receipt papers, and currency. Vitellogenin (Vtg), a yolk precursor protein synthesized in the liver and present in oviparous fish, particularly males, serves as a pertinent biomarker for studying the effects of estrogenic EDCs on fish. This study aimed to assess the impact of BPS on reproductive parameters and hepatic vitellogenin expression in Channa striatus. The LC50 of BPS was determined to be 128.8 mg/L. Experimental groups included control and BPS-exposed fish, with sub-lethal concentrations of BPS (1 mg/L, 4 mg/L, and 12 mg/L) administered and effects monitored at seven- and twenty-one-day intervals. Significant decreases in gonadosomatic index (GSI), ova diameter, and fecundity were observed in BPS-exposed Channa striatus. Hepatic Vtg mRNA expression was downregulated in female and upregulated in male following BPS exposure. Serum hormone analysis confirmed the estrogenic activity of BPS. These findings underscore BPS's ability as an endocrine disruptor to interfere with hormone synthesis and disrupt spermatogenesis and oogenesis processes in Channa striatus. This research contributes to understanding the endocrine-disrupting effects of BPS on aquatic organisms, highlighting potential ecological implications and the need for continued monitoring and regulatory considerations.

Oestrogens, adipose tissues and environmental exposures influence obesity and diabetes across the lifecycle

Endogenous oestrogens regulate essential functions to include menstrual cycles, energy balance, adipose tissue distribution, pancreatic β-cell function, insulin sensitivity and lipid homeostasis. Oestrogens are a family of hormones which include oestradiol (E2), oestrone (E1) and oestriol (E3). Oestrogens function by binding and activating oestrogen receptors (ERs). Phytoestrogens are plant-derived compounds which exhibit oestrogenic-like activity and can bind to ERs. Phytoestrogens exert potential oestrogenic-like benefits; however, their effects are context-dependent and require cautious consideration regarding generalised health benefits. Xenoestrogens are synthetic compounds which have been determined to disrupt endocrine function through binding to ERs. Xenoestrogens enter the body through various routes and given their chemical structure they can accumulate, posing long-term health risks. Xenoestrogens interfere with endogenous oestrogens and their functions contributing to conditions like cancer, infertility, and metabolic disorders. Understanding the interplay between endogenous and exogenous oestrogens is critical in order to determine their potential health consequences and requires further investigation. This manuscript provides a summary of the role endogenous oestrogens have in regulating metabolic functions. Additionally, we discuss the impact phytoestrogens and synthetic xenoestrogens have on biological systems across various life stages. We highlight their mechanisms of action, potential benefits, risks and discuss the need for further research to bridge gaps in understanding and mitigate exposure-related health risks.

Main factors influencing the perceived health risk of endocrine-disrupting chemicals: A systematic literature review

Endocrine-disrupting chemicals (EDCs) are linked to rising health issues such as infertility, childhood obesity, and asthma. While some research exists on health risk perceptions of EDCs, a comprehensive understanding across different populations and contexts is needed. We performed a systematic literature review, examining 45 articles published between 1985 and 2023, focusing on both the risk perception of EDCs as a whole as well as individual EDCs found in the environment (e.g., pesticides, bisphenol A, and phthalates). We identified four major categories of factors influencing EDC risk perception: sociodemographic factors (with age, gender, race, and education as significant determinants), family-related factors (highlighting increased concerns in households with children), cognitive factors (indicating that increased EDC knowledge generally led to increased risk perception), and psychosocial factors (with trust in institutions, worldviews, and health-related concerns as primary determinants). This review highlights the complex nature of EDC risk perception, shaped by sociodemographic, family, cognitive, and psychosocial factors, essential for policymakers in crafting educational and communication strategies. Future research should expand to cover more EDCs, use representative samples, and explore the influence of psychosocial factors on risk perception more deeply.

Comparative study of cytotoxic Signaling pathways in H1299 cells exposed to alternative Bisphenols: BPA, BPF, and BPS

Background

Bisphenols are prevalent in food, plastics, consumer goods, and industrial products. Bisphenol A (BPA) and its substitutes, bisphenol F (BPF) and bisphenol S (BPS), are known to act as estrogen mimics, leading to reproductive disorders, disruptions in fat metabolism, and abnormalities in brain development.

Objectives

Despite numerous studies exploring the adverse effects of bisphenols both in vitro and in vivo, the molecular mechanisms by which these compounds affect lung cells remain poorly understood. This study aims to compare the effects of BPA, BPF, and BPS on the physiological behavior of human nonsmall cell lung cancer (NSCLC) cells.

Materials and Methods

Human non-small cell lung cancer (NSCLC) H1299 cells were treated with various concentration of BPA, BPF and BPS during different exposure time. Cellular physiology for viability and cell cycle was assessed by the staining with apoptotic cell makers such as active Caspase-3 and cyclins antibodies. Toxicological effect was quantitatively counted by using flow-cytometry analysis.

Results

Our findings indicate that BPA induces apoptosis by increasing active Caspase-3 levels in H1299 cells, whereas BPF and BPS do not promote late apoptosis. Additionally, BPA was found to upregulate cyclin B1, causing cell cycle arrest at the G0/G1 phase and leading to apoptotic cell death through Caspase-3 activation. Conclusion: These results demonstrate that BPA, BPF, and BPS differentially impact cell viability, cell cycle progression, and cell death in human NSCLC cells.

New advanced models (NAMs) for risk assessment of bisphenol A alternatives

The safety of bisphenol A (BPA) due to its adverse effects on the immune system has led to an increasing concern and a significant regulatory shift. The European Food Safety Authority (EFSA) proposed a reduction in the tolerable daily intake (TDI) of BPA in food in their 2023 scientific opinion, highlighting the need for stricter regulations compared to their previous assessment in 2015. This regulatory action has spurred the production of BPA alternatives, raising concerns about their safety due to insufficient toxicological data. Addressing this gap is crucial for ensuring human and environmental health. In this project, multiple genotoxicity endpoints were applied for testing of two regulatory relevant BPA alternatives, bisphenol E (BPE) and bisphenol P (BPP), in different human models: 2D HepG2 liver cells, 3D liver spheroids and primary human peripheral blood lymphocytes. DNA strand breaks and oxidised base lesions were evaluated by the enzyme-modified version of the comet assay, while clastogenicity and aneugenicity were analysed by the in vitro micronucleus assay (OECD TG 487, 2016), together with cytotoxicity. Development of new advanced models (NAMs), as 3D spheroids, are essential for next-generation risk assessment (NGRA) in line with the 3R's to replace, reduce or refine animal experiments. In this aspect, validation and standardisation of NAMs are needed to reach regulatory readiness level and development of OECD Test Guidelines. Therefore, a standardisation and pre-validation of the advanced 3D liver spheroid model was performed by using multiple genotoxicity endpoints and by comparing the obtained results with standard genotoxicity models.

Functionalized composite nanofiber membranes for selective steroid hormone micropollutants uptake from water: Role of cyclodextrin type

Cyclodextrins (CD) entrapped in nanofiber composite membranes are potential selective adsorbing materials to remove steroid hormone (SHs) micropollutants from water. This study aims to elucidate the role of CD macrocyclic host type on the SHs inclusion complexation and uptake in filtration. Three CD types (α, β, and γ) are cross-linked with epichlorohydrin to form polymers (αCDP, βCDP and γCDP) and entrapped into a nanofiber composite membrane by electrospinning. TGA analysis confirmed the CD entrapment into the nanofiber without loss of CD molecules during filtration. The CD type plays a dominant role in controlling the removal of different SHs. A similar removal (range 33 to 50 %) was observed with αCDP, irrespective of the SH type. In contrast, removal and uptake dependent on SH type were observed for β and γCDP, with the highest removal of 74 % for progesterone, followed by estradiol (46 %) and estrone (27 %) and the lowest removal of 3 % for testosterone. Molecular dynamic (MD) simulation revealed a stronger and more stable complex formed with βCDP, as demonstrated by: i) the closer spatial distribution of SH molecules from the βCDP cavity and, ii) the quantum chemistry calculations of the lower de-solvation energy (+6.0 kcal/mol), which facilitates the release of water molecules from interacting interface of CD molecule and hormone. Regarding γCDP, the highest de-solvation energy (+8.3 kcal/mol) poses an energetic barrier, which hinders the formation of the inclusion complex. In the case of αCDP, a higher interaction energy (-8.9 kcal/mol) compared to βCDP (-4.9 kcal/mol) was obtained, despite the broader spatial distribution observed from the MD simulation attributed to a dominant hydrogen bonding interaction with the OH primary groups on the external surface cavity. The findings highlight the relevance of the CD type in designing selective adsorbing membranes for steroid hormone micropollutant uptake. Experimental results and MD simulation suggest that βCD is the most suitable CD type for steroid hormone uptake, due to a more stable and stronger inclusion complexation than α and γCD.

A pilot study: relationship between Bisphenol A, Bisphenol-glucuronide and total 25 hydroxy vitamin D in maternal-child pairs in a South African population

Introduction

Exposure to Bisphenol A (BPA) during early development particularly in-utero has been linked to a wide range of pathology. Over the last two decades the importance of vitamin D in maternal and child health has been highlighted. The aim of this pilot study was to examine the relationship of BPA and its naturally occurring metabolite BPA-glucuronide (BPA-g) with 25-hydoxy vitamin D (25OHD) levels in South African mother-child pairs.

Methods

Third-trimester serum maternal samples and matching cord blood samples were analyzed for BPA and BPA-g using liquid chromatography tandem mass spectrometry (LC-MS/MS) and 25OHD3 and 25OHD2 using high performance liquid chromatography. A total of 58 maternal and child pairs were analyzed.

Results

More than fifty percent of maternal-child pairs were noted to be vitamin D deficient or insufficient using the Endocrine Society Practice guidelines cut-off of 50 nmol/L. Spearman rank correlation and Kruskal Wallis analysis did not show statistically significant relationship between cord 25OHD (total) and maternal and cord BPA-g concentrations. Analysis of covariance after controlling for confounders showed a significant relationship between cord BPA-g levels and cord 25OHD levels (p=0.03) as well as between maternal BPA-g levels (p=0.04) and cord total 25OHD levels (p=0.04).

Discussion

The findings of the current study indicate a possible relationship with BPA/BPA-g and fetal/early infant Vitamin D levels that needs to be further investigated in this population.

Characterization of Chemical Exposome in A Paired Human Preconception Pilot Study

Parental preconception exposure to synthetic chemicals may have critical influences on fertility and reproduction. Here, we present a robust LC-MS/MS method covering up to 95 diverse xenobiotics in human urine, serum, seminal and follicular fluids to support exposome-wide assessment in reproductive health outcomes. Extraction recoveries of validated analytes ranged from 62% to 137% and limits of quantification from 0.01 to 6.0 ng/mL in all biofluids. We applied the validated method to a preconception cohort of Australian couples (n = 30) receiving fertility treatment. In total, 36 and 38 xenobiotics were detected across the paired biofluids of males and females, respectively, including PFAS, parabens, organic UV-filters, plastic additives, antimicrobials, and other industrial chemicals. Results showed 39% of analytes in males and 37% in females were equally detected in paired serum, urine, and reproductive fluids. The first detection of the sunscreen ingredient avobenzone and the industrial chemical 4-nitrophenol in follicular and seminal fluids suggests they can cross both blood-follicle/testis barriers, indicating potential risks for fertility. Further, the blood-follicle transfer of perfluorobutanoic acid, PFOA, PFHxS, PFOS, and oxybenzone corroborate that serum concentrations can be reliable proxies for assessing exposure within the ovarian microenvironment. In conclusion, we observed significant preconception exposure to multiple endocrine disruptors in couples and identified potential xenobiotics relevant to male and female fertility impairments.

The Influence of Environmental Exposure to Xenoestrogens on the Risk of Cancer Development

Xenoestrogens (XEs) are a group of exogenous substances that may interfere with the functioning of the endocrine system. They may mimic the function of estrogens, and their sources are plants, water or dust, plastic, chemical agents, and some drugs. Thus, people are highly exposed to their actions. Together with the development of industry, the number of XEs in our environment increases. They interact directly with estrogen receptors, disrupting the transmission of cellular signals. It is proven that XEs exhibit clinical application in e.g., menopause hormone therapy, but some studies observed that intense exposure to XEs leads to the progression of various cancers. Moreover, these substances exhibit the ability to cross the placental barrier, therefore, prenatal exposure may disturb fetus development. Due to the wide range of effects resulting from the biological activity of these substances, there is a need for this knowledge to be systematized. This review aims to comprehensively assess the environmental sources of XEs and their role in increasing cancer risk, focusing on current evidence of their biological and pathological impacts.

Study of Endocrine-Disrupting Chemicals in Infant Formulas and Baby Bottles: Data from the European LIFE-MILCH PROJECT

Exposure to endocrine-disrupting chemicals (EDCs) is inevitable, and growing scientific evidence indicates that even very low doses can negatively impact human health, particularly during pregnancy and the neonatal period. As part of the European project LIFE18 ENV/IT/00460, this study aims to identify the presence of EDCs in 20 infant formulas (both powdered and liquid) and the release from baby bottles and teats. Particularly, sensitization of young people and future parents towards the potential harmful effects of EDCs could significantly help to reduce exposure. Seven different UPLC-MS/MS methodologies and one ICP-AES were set up to quantify already assessed and suspected EDCs among 85 different chemicals (bisphenols, parabens, PAHs, phthalates, pesticides, herbicides and their main metabolites, PFAS, and metals). Results showed that in 2 out of 14 baby bottles, only anthracene and phenanthrene of the group of PAHs were released (10.68-10.81 ng/mL). Phthalates such as mono-ethyl phthalate (MEP) were found in 9 of 14 samples (0.054-0.140 ng/mL), while mono(2-ethyl-5-oxohexyl) phthalate (MeOHP) appeared in 2 samples (0.870-0.930 ng/mL). In accordance with current EU regulations, other chemicals were not detected in baby bottles and teats. However, bisphenols, parabens, PAHs, phthalates, PFAS, and metals were detected in infant formula, emphasizing the need for continued monitoring and public health interventions.

Persistent endocrine-disrupting chemicals and incident uterine leiomyomata: A mixtures analysis

BACKGROUND

Uterine leiomyomata (UL; fibroids) are hormone-dependent neoplasms that can cause significant gynecologic morbidity. Studies have documented associations between concentrations of persistent endocrine-disrupting chemicals (EDCs) and UL incidence; however, few have assessed the effects of EDC mixtures on UL.

METHODS

In the Study of Environment, Lifestyle, and Fibroids, a prospective cohort study, participants attended study visits at baseline and approximately every 20 months for up to 10 years; at each visit, they completed questionnaires, provided blood samples, and underwent standardized ultrasound examinations. In baseline plasma samples (n = 1155), we quantified concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides using high-resolution mass spectrometry. We selected nine EDCs detected in >60 % of samples (4 PCBs, 4 PBDEs, and 2,2-bis(4-chlorophenyl)-1,1-dichloroethene (p,p'-DDE)) and conducted probit Bayesian kernel machine regression with hierarchical variable selection to estimate effects of the EDC mixture and individual EDCs on UL incidence, adjusting for potential confounders.

RESULTS

During 10 years of follow-up, 32 % of participants developed ultrasound-detected UL. The EDC mixture was not appreciably associated with the probit of UL (β comparing all EDCs at their 75th vs. 50th percentile:= - 0.01, 95 % credible interval [CrI]: -0.11, 0.10). However, individual EDC concentrations were associated with UL in opposing directions: PCB138/158 was positively associated with UL (β for 25th-to-75th-percentile increase when all other chemicals were set to their 50th percentile = 0.18, 95 % CrI: -0.09, 0.44), whereas PBDE99 and p,p'-DDE were inversely associated with UL (β = -0.06, 95 % CrI: -0.21, 0.10 and β = -0.12, 95 % CrI: -0.34, 0.10, respectively). There was little evidence of interaction between EDCs.

CONCLUSION

In this prospective ultrasound study, a mixture of persistent EDCs was not appreciably associated with incident UL during 10 years of follow-up, but individual EDCs were associated with UL in opposite directions.

Management of phthalates in Canada and beyond: can we do better to protect human health?

Ortho-phthalates (herein referred to as phthalates) are synthetic chemicals used in thousands of different everyday products and materials. Nearly ubiquitous environmental exposure is reflected by phthalate metabolites in the urine of almost all Canadians. However, phthalate exposure tends to be higher amongst people of low socioeconomic status and ethnic minorities. Substantial evidence shows that certain phthalates cause harm to human health, particularly developing fetuses and children. Governments vary in their approach to assessing and managing risks associated with phthalates. Canada continues to take a more permissive stance on phthalate regulations compared to the EU and some US states. We argue that the recent Canadian national risk assessment on phthalates does not appropriately reflect the growing evidence demonstrating harm to human health from phthalate exposure and does not adequately consider the evidence showing higher exposures faced by vulnerable populations. Canadians would benefit from adopting a more stringent regulatory approach to phthalates. Specifically, Canada should expand phthalate restrictions to apply to all consumer products, implement sunset dates toward eliminating the use of existing phthalates, and mandate publicly available evidence of no harm for phthalate alternatives. Canadian alignment on phthalate regulations with the EU and a growing number of US states could encourage other countries to follow suit.

The Effect of Ketoconazole and Quinestrol Combination on Reproductive Physiology in Male Mice

This study investigates whether ketoconazole, a CYP3A4 inhibitor, can enhance the suppressive effects of quinestrol on reproductive capacity, potentially allowing for a reduced quinestrol dosage while maintaining its efficacy. A total of 104 healthy adult male mice were divided into two groups, assessed at 10 and 30 days. Within each group, six treatment categories were tested: the control (CK), quinestrol alone (Q1, Q5), and quinestrol combined with varying doses of ketoconazole (Q1 + K0.4, Q1 + K2, Q5 + K0.4). The key parameters measured included internal and reproductive organ weights, sperm density, sperm motility, sperm abnormalities, and CYP3A4 enzyme content in intestinal and liver tissues. After 10 days, the combination of a low dose of quinestrol with ketoconazole (Q1 + K0.4) showed the most significant pronounced effects in reducing reproductive potential, with notable reductions in epididymal weight, sperm density, sperm abnormality rate and vitality, serum hormone levels, and CYP3A4 content in the small intestine and liver. Although some reproductive parameters returned to near-baseline levels after 30 days, the Q1 + K0.4 regimen continued to exhibit reduced seminal vesicle weight and testosterone levels. Importantly, the combination did not significantly increase CYP3A4 enzyme content, indicating effective metabolic inhibition. The combination of quinestrol and ketoconazole, especially the Q1 + K0.4 regimen, demonstrated the most noticeable impact on reducing reproductive capacity. This regimen significantly reduced key reproductive parameters and showed strong metabolic inhibition, suggesting that ketoconazole substantially enhances the efficacy of quinestrol in fertility control.

Endocannabinoid System and Metabolism: The Influences of Sex

The endocannabinoid system (ECS) is a lipid signaling system involved in numerous physiological processes, such as endocrine homeostasis, appetite control, energy balance, and metabolism. The ECS comprises endocannabinoids, their cognate receptors, and the enzymatic machinery that tightly regulates their levels within tissues. This system has been identified in various organs, including the brain and liver, in multiple mammalian and non-mammalian species. However, information regarding the sex-specific regulation of the ECS remains limited, even though increasing evidence suggests that interactions between sex steroid hormones and the ECS may ultimately modulate hepatic metabolism and energy homeostasis. Within this framework, we will review the sexual dimorphism of the ECS in various animal models, providing evidence of the crosstalk between endocannabinoids and sex hormones via different metabolic pathways. Additionally, we will underscore the importance of understanding how endocrine-disrupting chemicals and exogenous cannabinoids influence ECS-dependent metabolic pathways in a sex-specific manner.

Perinatal bisphenol A exposure has an age- and dose-dependent association with thyroid allostasis adaptive response, as well as anxiogenic-depressive-like and asocial behaviors in juvenile and adult male rats

Thyroid hormones are essential for brain development, and a shortage throughout the fetal and postnatal periods can result in mood disorders. Perinatal exposure to bisphenol A (BPA) affects thyroid activity and dependent processes indirectly during pregnancy or early postnatal life. This is particularly important because it may cause changes in tissue ontogeny, increasing the risk of developing disorders later in life. The study aimed to investigate the consequences of thyroid hormone deficiency on anxiety, social, and depressive behaviors, as well as disruption in thyroid peroxidase (TPO) gene expression, which influences the NF-κB/Nrf-2/HO-1/iNOS signaling pathway, leading to oxidative stress, inflammation, and DNA fragmentation in perinatal BPA exposure (PND18), and whether these effects can be observed in juvenile (PND60) and adult (PND95) male offspring rats. BPA increased anxiety-like behavior while decreasing sucrose preference and sociability on a choice task between novel conspecific male rats and enhanced immobility on the forced swim test. Perinatal exposure to BPA causes thyroid insult by overproducing ROS, increasing iNOS, and NF-κB levels-these effects, in turn, down-regulate Nrf-2/HO-1 signaling, resulting in DNA fragmentation within thyroid tissues. Furthermore, perinatal BPA exposure for 60 and 95 days resulted in a significant fold decrease in TPO mRNA levels in the thyroid tissues, with an insignificant fold rise in TPO expression levels in BPA 50-60. In conclusion, the present study found that perinatal BPA exposure induced thyroid allostasis-adaptive response by inhibiting the NF-κB/Nrf-2/HO-1/iNOS signaling pathway and altering the transcriptional expression of TPO, where TSH reinforced a possible association with TPO activity, disrupting thyroid hormone synthesis in juvenile rats and gradual deterioration reaching the adult stage.

Additives in Processed Foods as a Potential Source of Endocrine-Disrupting Chemicals: A Review

Processed foods, accounting for most consumable food categories today, contain considerable amounts of food additives. Food additives are substances added to food products to improve taste, consistency, appearance, or shelf life. Various food additives, such as phthalates, bisphenol A, tartrazine, erythrosine, artificial sweeteners, and parabens, have been identified as potential sources of endocrine-disrupting chemicals (EDCs) in processed foods. EDCs are substances that frequently interfere with the regular functioning of the endocrine system, creating an unusual environment in the biological system, which leads to adverse health effects such as the disruption of hormone synthesis, receptor binding, and signal transduction pathways, as well as energy metabolic homeostatic disorders which potentially increasing the risk of obesity, type-2 diabetes, cardiometabolic diseases and may also trigger allergic reactions. Consequently, they can also impact mammary gland development, and reproductive function, further leading to developmental abnormalities. This review aims to insights into the various food additives that act as potential endocrine-disrupting chemicals (EDCs) and to describe their applications in the food industry, as well as the failure of hormonal homeostatic mechanisms, which eventually result in hazardous health effects. It also outlines strategies to reduce the use of food additives and suggests alternative additives with minimal or no endocrine-disrupting properties, highlighting their importance for maintaining human health.

Supplementation of high doses of vitamin D during the gestational period do not cause reproductive, teratogenic and genotoxic damage in mice

Vitamin D deficiency during pregnancy may have adverse effects on embryo-fetal and postnatal development. Indeed, vitamin D supplementation has been indicated for pregnant women. However, there are no studies that indicate the safe dose of this supplementation during the gestational period. Therefore, the present study assessed the effects of high doses of vitamin D and vitamin D combined with calcium on reproductive performance, embryo-fetal development, and DNA integrity in Swiss mice. A total of 140 pregnant female mice treated with vitamin D and vitamin D combined with calcium were analyzed in two experiments. In one experiment, mice received intramuscular supplementation at doses of 600,000, 6,000,000, or 60,000,000 IU of vitamin D. These same doses were also associated with the dose of 8.56 mg/kg of calcium. In the other experiment, mice received a single oral dose of 6,000, 60,000, or 600,000 IU of vitamin D. These same doses were also associated with the dose of 8.56 mg/kg of calcium. The treatments were always carried out in the 10th gestational day. The results show that neither intramuscularly nor orally administered vitamin D and vitamin D combined with calcium affected reproductive performance, embryo-fetal development, or DNA integrity at the different doses tested. These pioneering results confirm the safety of using this type of high doses of supplementation, including during pregnancy.

Pyrethroids and reproductive function: some endocrine disrupting perspectives from molecular simulations

Pyrethroids are widely used insecticides with huge applications for household as well as agricultural purposes and contribute to improved product quality and higher yields. In recent decades, the demand for pyrethroids has increased significantly due to advantages such as broad-spectrum efficacy, high insecticidal potential, and lower pest resistance. However, several studies have suggested that human exposure to pyrethroids leads to reproductive problems. Sex hormone-binding globulin (SHBG) is an important hormone transport protein regulating the availability of steroids at their target site. The aim of our study was to investigate the structural interactions of commonly used pyrethroids, cypermethrin and deltamethrin, with ligand binding pocket of SHBG. Cypermethrin and deltamethrin were docked into the steroid binding pocket of SHBG using Schrodinger's induced fit docking (IFD) followed by molecular dynamics (MD) simulation studies. The resultant SHBG-pyrethroid complexes from IFD experiments were subjected to structural analysis including the molecular interactions followed by binding energy estimation. The analysis revealed that both the ligands were tightly bound in the SHBG pocket with high percentage of commonality among the SHBG residues between the indicated pyrethroid ligands and the SHBG native ligand, dihydrotestosterone (DHT). The estimated binding energy values for cypermethrin were less but close to the values calculated for the SHBG native ligand, DHT. However, the estimated binding energy values for deltamethrin were higher compared to the values calculated for SHBG native ligand, DHT. Furthermore, the MD simulation results also revealed the higher stability of SHBG-deltamethrin than SHBG-cypermethrin complex. To sum up, the results suggested that deltamethrin has a greater capability than cypermethrin to prevent sex steroid hormone from binding to SHBG, even though both pyrethroids have this ability. Consequently, this might hamper the circulatory transport of sex steroid hormones and their availability at the target site, subsequently interfering with reproductive function.

BPA induces testicular damage in male rodents via apoptosis, autophagy, and ferroptosis

Bisphenol A (BPA), chemically known as 2,2-bis(4-hydroxyphenyl) propane, is one of the most common endocrine-disrupting chemicals in our environment. Long-term or high-dose exposure to BPA may lead to testicular damage and adversely affect male reproductive function. In vivo studies on rodents have demonstrated that BPA triggers apoptosis in testicular cells through both intrinsic and extrinsic pathways. Further in vitro studies on spermatogonia, Sertoli cells, and Leydig cells have all confirmed the pro-apoptotic effects of BPA. Given these findings, apoptosis is considered a primary mode of cell death induced by BPA in testicular tissue. In addition, BPA promotes autophagy by altering the activity of the Akt/mTOR pathway and upregulating the expression of autophagy-related genes and proteins. Recent studies have also identified ferroptosis as a significant contributing factor to BPA-induced testicular damage, further complicating the landscape of BPA's effects. This review summarizes natural substances that mitigate BPA-induced testicular damage by inhibiting these cell death pathways. These findings not only highlight potential therapeutic strategies but also underscore the need for further research into the underlying mechanisms of BPA-induced toxicity, particularly as it pertains to human health risk assessment and the development of more effective BPA management strategies.

Luteolin detoxifies DEHP and prevents liver injury by degrading Uroc1 protein in mice

Di-(2-ethylhexyl) phthalate (DEHP), an environmental pollutant, has been widely detected in both environmental and clinical samples, representing a serious threat to the homeostasis of the endocrine system. The accumulation of DEHP is notably pronounced in the liver and can lead to liver damage. The lack of effective high-throughput screening system retards the discovery of such drugs that can specifically target and eliminate the detrimental impact of DEHP. Here, by developing a Cy5-modified single-strand DNA-aptamer-based approach targeting DEHP, we have identified luteolin as a potential drug, which showcasing robust efficacy in detoxifying the DEHP by facilitating the expulsion of DEHP in both mouse primary hepatocytes and livers. Mechanistically, luteolin enhances the protein degradation of hepatic urocanate hydratase 1 (Uroc1) by targeting its Ala270 and Val272 sites. More importantly, trans-urocanic acid (trans-UCA), as the substrate of Uroc1, possesses properties similar to luteolin by regulating the lysosomal exocytosis through the inhibition of the ERK1/2 signal cascade. In summary, luteolin serves as a potent therapeutic agent in efficiently detoxifying DEHP in the liver by regulating the UCA/Uroc1 axis.

Bacterial Catabolism of Phthalates With Estrogenic Activity Used as Plasticisers in the Manufacture of Plastic Products

Phthalic acid esters (PAEs), the pervasive and ubiquitous endocrine-disrupting chemicals of environmental concern, generated annually on a million-ton scale, are primarily employed as plasticisers in the production of a variety of plastic products and as additives in a large number of commercial supplies. The increased awareness of various adverse effects on the ecosystem and human health including reproductive and developmental disorders has led to a striking increase in research interest aimed at managing these man-made oestrogenic chemicals. In these circumstances, microbial metabolism appeared as the major realistic process to neutralise the toxic burdens of PAEs in an ecologically accepted manner. Among a wide variety of microbial species capable of degrading/transforming PAEs reported so far, bacteria-mediated degradation has been studied most extensively. The main purpose of this review is to provide current knowledge of metabolic imprints of microbial degradation/transformation of PAEs, a co-contaminant of plastic pollution. In addition, this communication illustrates the recent advancement of the structure-functional aspects of the key metabolic enzyme phthalate hydrolase, their inducible regulation of gene expression and evolutionary relatedness, besides prioritising future research needs to facilitate the development of new insights into the bioremediation of PAE in the environment.

Pesticide exposure and oxidative stress generation are linked to poor prognosis outcomes in breast cancer women carrying the allelic variant rs7438135 in the UGT2B7 gene

Pesticide exposure is a risk factor for the development of several diseases, including breast cancer (BC). The enzyme UGT2B7 participate in detoxification of pesticides and the presence rs7438135 (G > A) variant in your gene increases its glucuronidation potential, contributing to oxidative stress metabolites neutralization. Here we investigated the impact of occupational pesticide exposure on the systemic oxidative stress generation from 228 women with BC depending on their UGT2B7 rs7438135 (G > A) status. q-PCR investigated the presence of the rs7438135 variant, and oxidative stress markers (lipid peroxidation levels, total antioxidant capacity-TRAP, and nitric oxide metabolites-NOx) were measured in plasma. Pesticide exposure induced significant augment in the systemic lipid peroxidation in the presence of the variant for several clinicopathological conditions, including tumors with high proliferation index (ki67) and with high aggressiveness. NOx was augmented in high ki67, positive progesterone receptors, high-grade and triple-negative/Luminal B tumors, and low-risk stratified patients. TRAP was depleted in young patients at menopause and those with triple-negative/Luminal B tumors, as well as those stratified as at low risk for death and recurrence. These findings showed that the presence of the variant was not able to protect from pesticide-induced oxidative stress generation in BC patients.

Prenatal phthalate exposure and pubertal development in 16-year-old daughters: reproductive hormones and number of ovarian follicles

STUDY QUESTION

Is there a possible association between prenatal phthalate exposure and late effects in teenage daughters with respect to reproductive hormone levels, uterine volume, and number of ovarian follicles?

SUMMARY ANSWER

Our study showed subtle associations between phthalate metabolite concentrations in maternal serum from pregnancy or cord blood and LH and insulin-like growth factor 1 (IGF-1) levels as well as uterine volume in their daughters 16 years later.

WHAT IS KNOWN ALREADY

Endocrine-disrupting environmental chemicals may adversely affect human reproductive health, and many societies have experienced a trend toward earlier puberty and an increasing prevalence of infertility in young couples. The scientific evidence of adverse effects of foetal exposure to a large range of chemicals, including phthalates, on male reproductive health is growing, but very few studies have explored effects on female reproduction.

STUDY DESIGN, SIZE, DURATION

This follow-up study included 317 teenage daughters who were part of the Copenhagen Mother-Child Cohort, a population-based longitudinal birth cohort of 1210 females born between 1997 and 2002.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 317 female participants (median age 16 years) were examined for weight, height, and menstrual pattern. A serum sample was analysed for concentrations of reproductive hormones, and trans-abdominal 3D ultrasonography was performed to obtain the number of ovarian follicles, ovarian and uterine size. Prenatal maternal serum samples were available for 115 females, and cord blood samples were available for 118 females. These were analysed for concentrations of 32 phthalate metabolites. Weighted quantile sum regression was used for modelling associations of combined prenatal phthalate exposure with the reproductive outcomes in post-menarcheal females.

MAIN RESULTS AND THE ROLE OF CHANCE

In bivariate correlation analyses, negative significant associations were found between several prenatal phthalate metabolite concentrations and serum hormone concentrations (testosterone, 17-OH-progesterone, and IGF-1) as well as number of ovarian follicles in puberty. Positive significant correlations were found between prenatal phthalate exposure and FSH and sex hormone-binding globulin concentrations. Combined analyses of phthalate exposure (weighted quantile sums) showed significant negative associations with IGF-1 concentration and uterine volume as well as a significant positive association with LH concentration.

LIMITATIONS, REASONS FOR CAUTION

Phthalate metabolites were measured in serum from single prenatal maternal blood samples and cord blood samples. Potential concomitant exposure to other endocrine-disrupting environmental chemicals before or after birth was not controlled for. The study population size was limited.

WIDER IMPLICATIONS OF THE FINDINGS

Our results support the need for further research into possible adverse effects of environmental chemicals during foetal development of the female reproductive system.

STUDY FUNDING/COMPETING INTEREST(S)

The work was supported by The Center on Endocrine Disruptors (CeHoS) under The Danish Environmental Protection Agency and The Ministry of Environment and Food (grant number: MST-621-00 065). No conflicts of interest are declared.

TRIAL REGISTRATION NUMBER

N/A.

Study on low concentration deltamethrin toxicity mediated by phospholipase D in Chinese mitten crab (Eriocheir sinensis) ovary

This study evaluates the impact of environmentally relevant, low-concentration deltamethrin exposure to Eriocheir sinensis ovaries. Our findings revealed that even at a concentration of 0.05 µg/L, deltamethrin exposure can induce significant ovarian toxicity through a 5-day exposure, with gradual amplification detected with time, demonstrating the toxicity amplification effect. Hematoxylin and Eosin staining revealed that low-concentration deltamethrin exposure produces pathological damage consistent with acute toxicity-yolk granules were dissolved and oocyte membranes were ruptured. High-throughput RNA-sequencing data indicated that the acute and low-concentration exposure groups involved completely different pathways and molecular functions, suggesting distinct mechanisms for their toxic effects. Following the identification of phospholipase D (PLD) as a potential core factor regulating the toxicity amplification effect of low concentration deltamethrin, we delved into subsequent mechanism studies using quantitative real-time PCR, immunofluorescence and enzyme-linked immunosorbent assay. Through the GnRH signaling pathway, increased PLD indirectly stimulates augmented estradiol secretion, subsequently inducing apoptosis by upregulating Cathepsin D, which can activate the key executioners of apoptosis-caspases (CASP3 and CASP7). In conclusion, low-concentration deltamethrin exposures can induce significant ovarian damage through apoptosis mediated by the upregulation of PLD in the ovaries of Eriocheir sinensis at environmentally relevant concentrations, which lays the preliminary theoretical groundwork for further elucidating the mechanism of toxicity amplification effect of pesticide exposure at low concentrations.

Impact of diethyl phthalate on freshwater planarian behaviour, regeneration, and antioxidant defence

Diethyl phthalate (DEP) has been widely used as a plasticiser in various consumer products, including cosmetics, personal care items, and pharmaceuticals, and recent studies reported a higher abundance of this priority phthalate in the aquatic environment. DEP is a potential endocrine disruptor, affecting immune systems in humans and wildlife even at low-level chronic exposure. As concern over phthalates increases globally, regulatory bodies focus more on their environmental impact. However, limited research is available, particularly using model organisms like planarians. Planarians are ideal for toxicological studies and may provide insightful information on pollutants' neurotoxic, developmental, and ecological effects, especially in freshwater environments where planarians play a vital role in ecosystem balance. Therefore, the objective of the current study was to examine the toxicity of DEP using the freshwater Dugesia sp., as an experimental animal. The LC50 for the test organism was calculated using DEP concentrations of 800, 400, 200, 100, and 50 µM, with an estimated LC50 of 357.24 µM. Furthermore, planarians were exposed to sub-lethal DEP concentration (178.62 µM) for one day as well as eight days to evaluate the impact of DEP on planarian locomotion, feeding behaviour, and regeneration ability. At sub-lethal concentration, locomotion and feeding ability were decreased, and regeneration was delayed. Furthermore, neuro-transmittance in planaria was altered by sub-lethal DEP concentration, as indicated by a reduced acetylcholinesterase (AChE) activity. DEP exposure induced oxidative damage in the tested planarians as shown by a marked increase in stress biomarkers, including lipid peroxidation levels and antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and glutathione S-transferase (GST). Our study revealed that DEP exposure may prove fatal to freshwater organisms, such as planarians. The observed alterations in behaviour and regeneration ability demonstrate the severity of the effects exerted by DEP as a toxicant in aquatic ecosystems, thereby indicating the need to restrict its usage to protect aquatic environments.

Bisphenol A triggers activation of ocular immune system and aggravates allergic airway inflammation

Bisphenol A (BPA) is widely used in manufacturing plastic products, and it has been reported that exposure through the airway or orally aggravates allergic airway inflammation. Because BPA is detected in the atmosphere and indoor environments, the eyes can also be exposed to BPA. After ocular exposure to BPA and antigen via eye drops, we observed enhanced antigen uptake of antigen-presenting cells (APCs) in tear duct-associated lymphoid tissue (TALT). Additionally, we observed the formation of germinal center (GC) B cells in TALT and induction of allergic airway inflammation in mice sensitized with BPA and antigen via eye drops, followed by airway antigen exposure. We also found that DNAX-activating protein of 12 kDa (DAP12)-deficient mice displayed impaired activation of APCs enhanced by ocular exposure to BPA. These results indicate that ocular sensitization to BPA and allergen triggers allergic inflammation via TALT activation, and that DAP12 might be a key molecule for modulating the ocular immune system.

Small phenolic compounds as potential endocrine disruptors interacting with estrogen receptor alpha

The human body is regularly exposed to simple catechols and small phenols originating from our diet or as a consequence of exposure to various industrial products. Several biological properties have been associated with these compounds such as antioxidant, anti-inflammatory, or antiplatelet activity. Less explored is their potential impact on the endocrine system, in particular through interaction with the alpha isoform of the estrogen receptor (ERα). In this study, human breast cancer cell line MCF-7/S0.5 was employed to investigate the effects on ERα of 22 closely chemically related compounds (15 catechols and 7 phenols and their methoxy derivatives), to which humans are widely exposed. ERα targets genes ESR1 (ERα) and TFF1, both on mRNA and protein level, were chosen to study the effect of the tested compounds on the mentioned receptor. A total of 7 compounds seemed to impact mRNA and protein expression similarly to estradiol (E2). The direct interaction of the most active compounds with the ERα ligand binding domain (LBD) was further tested in cell-free experiments using the recombinant form of the LBD, and 4-chloropyrocatechol was shown to behave like E2 with about 1/3 of the potency of E2. Our results provide evidence that some of these compounds can be considered potential endocrine disruptors interacting with ERα.

Occupational Exposure to Benzene and Risk of Breast Cancer: Systematic Review and Meta-Analysis

INTRODUCTION

Benzene is a recognized carcinogen; however, its association with breast cancer is not well established. Hence, a meta-analysis of cohort and case-control studies was performed to determine the association between occupational benzene exposure and the risk of breast cancer.

METHODS

A systematic literature review identified 7573 publications from which 23 cohort and case-control studies were retained and evaluated using meta-analyses (fixed effects model). PRISMA guidelines were followed. Our protocol was registered in the PROSPERO database (Registration No. CRD42022379720). Study quality was assessed using a modified Newcastle-Ottawa scale (NOS).

RESULTS

The summary relative risk (RR) for ever-benzene exposure was 1.08 (95% CI=1.03-1.14, I2=38.6%, n=23 risk estimates); corresponding RR for cancer incidence and mortality were 1.08 (95% CI=1.02-1.14, I2=56.1%, n=16) and 1.10 (95% CI=0.87-1.37, I2<0.001%, n=10). However, heterogeneity was detected for sex (p-het=0.002), publication year (p-het<0.001), study design (p-het<0.001), study quality (p-het<0.001), and industry of employment (p-het=0.03). The RR for high level of exposure showed positive association with breast cancer 1.35 (95% CI=1.06-1.72, I2 =<0.001%, n=3) and (P-het=0.64). Publication bias was detected (p=0.03).

CONCLUSIONS

The results of our meta-analysis indicate a positive association between occupational benzene exposure and an increased risk of breast cancer, particularly when exposed to higher levels of benzene. However, bias and confounding could not be excluded.

Endocrine-Disrupting Chemicals, Hypothalamic Inflammation and Reproductive Outcomes: A Review of the Literature

Endocrine-disrupting chemicals (EDCs) are environmental and industrial agents that interfere with hormonal functions. EDC exposure is linked to various endocrine diseases, especially in reproduction, although the mechanisms remain unclear and effects vary among individuals. Neuroinflammation, particularly hypothalamic inflammation, is an emerging research area with implications for endocrine-related diseases like obesity. The hypothalamus plays a crucial role in regulating reproduction, and its inflammation can adversely affect reproductive health. EDCs can cross the blood-brain barrier, potentially causing hypothalamic inflammation and disrupting the reproductive axis. This review examines the existing literature on EDC-mediated hypothalamic inflammation. Our findings suggest that exposure to 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD), polychlorinated biphenyl (PCB), tributyltin (TBT), phthalates, bisphenol A (BPA), and chlorpyrifos (CPF) in animals is linked to hypothalamic inflammation, specifically affecting the hypothalamic centers of the gonadotropic axis. To our knowledge, this is the first comprehensive review on this topic, indicating hypothalamic inflammation as a possible mediator between EDC exposure and reproductive dysfunction. Further human studies are needed to develop effective prevention and treatment strategies against EDC exposure.

Short-Term Exposure to Foodborne Xenoestrogens Affects Breast Cancer Cell Morphology and Motility Relevant for Metastatic Behavior In Vitro

Breast cancer is highly susceptible to metastasis formation. During the time of disease progression, tumor pathophysiology can be impacted by endogenous factors, like hormonal status, as well as by environmental exposures, such as those related to diet and lifestyle. New lines of evidence point toward a potential role for foodborne endocrine disruptive chemicals in this respect; however, mechanistic understanding remains limited. At the molecular level, crucial steps toward metastasis formation include cell structural changes, alteration of adhesion, and reorganization of cytoskeletal proteins involved in motility. Hence, this study investigates the potential of dietary xenoestrogens to impact selected aspects of breast cancer cell mechanotransduction. Taking the onset of the metastatic cascade as a model, experiments focused on cell-matrix adhesion, single-cell migration, and adaptation of cell morphology. Dietary mycoestrogens alternariol (AOH, 1 μM) and α-zearalenol (α-ZEL, 10 nM), soy isoflavone genistein (GEN, 1 μM), and food packaging plasticizer bisphenol A (BPA, 10 nM) were applied as single compounds or in mixtures. Pursuing the hypothesis that endocrine active molecules could affect cell functions beyond the estrogen receptor-dependent cascade, experiments were performed comparing the MCF-7 cell line to the triple negative breast cancer cells MDA MB-231. Indeed, the four compounds functionally affected the motility and the adhesion of both cell types. These responses were coherent with rearrangements of the actin cytoskeleton and with the modulation of the expression of integrin β1 and cathepsin D. Mechanistically, molecular dynamics simulations confirmed a potential interaction with fragments of the α1 and β1 integrin subunits. In sum, dietary xenoestrogens proved effective in modifying the motility and adhesion of breast cancer cells, as predictive end points for metastatic behavior in vitro. These effects were measurable after short incubation times (1 or 8 h) and contribute to shed novel light on the activity of compounds with hormonal mimicry potential in breast cancer progression.

Environmental Stress-Induced Alterations in Embryo Developmental Morphokinetics

The association between embryo morphokinetics and its developmental competence is well documented. For instance, early cleaved embryos are more competent in developing to blastocysts, whereas the proportion of abnormally cleaved embryos that further developed to blastocysts is low. Numerous factors, such as the parental age, lifestyle, health, and smoking habits have been reported to affect the embryo morphokinetics and, consequently, its development. However, less is known about the effect of environmental stressors on embryo morphokinetics. The current review discusses the effect of the most concerning environmental stressors on embryo morphokinetics. These stresses include heat stress and human-made chemicals such as phthalates (e.g., bis-(2-ethylhexyl phthalate, dibutyl phthalate, dimethyl phthalate, and their primary metabolites), herbicides (e.g., diaminochlorotriazine, the primary metabolite of atrazine), pharmaceutical compounds (e.g., carbamazepine, nocodazole) and pro-oxidant agents (cumene hydroperoxide, Triton X-100), as well as naturally occurring toxins such as mycotoxin (e.g., aflatoxin B1 and its metabolite, and ochratoxin A). In addition, this review discusses the effect of ionizing or non-ionizing radiation and viral infections (e.g., SARS-CoV-2, papillomavirus). Finally, it points out some potential mechanisms that underlie the impairment of embryo morphokinetics, and it suggests protective compounds, mainly the supplementation of antioxidants to improve the morphokinetics, and consequently, the embryo developmental competence.