Effects of Prenatal Exposure to Bisphenol A Substitutes, Bisphenol S and Bisphenol F, on Offspring's Health: Evidence from Epidemiological and Experimental Studies

Tracing impacts of prenatal exposure to bisphenol analogues on child anogenital distance development: A birth-cohort study

Prenatal exposure to bisphenol analogues (BPs) is increasingly common and may affect children's reproductive development. However, human evidence is limited and inconsistent. Based on the Shanghai-Minhang Birth Cohort Study that enrolled participants in 2012 at Minhang Maternal and Child Health Hospital in Shanghai, China, we measured BPs in maternal urine samples collected during late pregnancy and children's anogenital distance (AGD: boys, AGDAP (anus-penis), AGDAS (anus-scrotum); girls, AGDAC (anus-clitoris), AGDAF (anus-fourchette)) from birth to 48 months as an indicator of reproductive development. A total of 545 mother-child pairs were included. Boys with detected maternal bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF) tended to have increased AGDAP at 6 months, while at 12 months, BPA, BPS, and BPAF were associated with a marginal decrease in AGDAP. In girls, higher levels of BPA, BPF and BPS were associated with longer AGD at 48 months and higher risks of rapid AGD growth. Bayesian kernel machine regression models showed significant associations between BPs mixtures and AGD in both sexes, with BPF and BPS identified as major contributors. Our study revealed the lasting, sex-specific impacts of prenatal exposure to BPA and its alternatives on children's reproductive development.

The Mechanism of Bisphenol S-Induced Atherosclerosis Elucidated Based on Network Toxicology, Molecular Docking, and Machine Learning

The increasing prevalence of environmental pollutants has raised public concern about their potential role in diseases such as atherosclerosis (AS). Existing studies suggest that chemicals, including bisphenol S (BPS), may adversely affect cardiovascular health, but the specific mechanisms remain unclear. This study aims to elucidate the effects of BPS on AS and the underlying mechanisms. Through an extensive search of databases such as ChEMBL, STITCH, SwissTargetPrediction, SuperPred, SEA, and GEO, we identified 34 potential targets related to BPS-induced AS. A target network was constructed using the STRING platform and Cytoscape software. GO and KEGG functional enrichment analysis using the DAVID database revealed that BPS may promote the occurrence of AS by interfering with critical biological processes such as glutathione metabolism, nitrogen metabolism, and tyrosine metabolism. This was followed by the selection of 4 core targets-aminopeptidase n (ANPEP), alcohol dehydrogenase 5 (ADH5), lysosomal pro-x carboxypeptidase (PRCP), and microsomal glutathione s-transferase 1 (MGST1)-using five machine learning methods. These core targets play a pivotal role in BPS-induced AS. Furthermore, molecular docking confirmed the tight binding between BPS and these core targets. In conclusion, this study provides a theoretical framework for understanding the molecular mechanisms of BPS-induced AS and contributes scientific evidence for the development of prevention and treatment strategies for cardiovascular diseases triggered by BPS exposure.

Epidermal growth factor receptor in placental health and disease: pathways, dysfunction, and chemical disruption

Formation of the placenta during gestation is required to support fetal growth and development. Derived from the placenta, trophoblast cells express nuclear and membrane-bound receptors. Among these receptors is the epidermal growth factor receptor (EGFR) which plays a key role in placental development. Activation of EGFR-mediated signaling in trophoblast cells regulates critical processes, such as proliferation, differentiation, invasion, and fusion during pregnancy, making it essential for normal placental formation. Dysfunction of EGFR in placental trophoblast cells has been associated with adverse pregnancy outcomes, including intrauterine growth restriction, preeclampsia, and preterm birth. Ubiquitous environmental chemicals, like polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, and bisphenols, have been reported to modulate EGFR signaling pathways, potentially contributing to placental dysfunction. This review explores the pivotal role of EGFR signaling in placental development and function, with a focus on how environmental chemicals interfere with EGFR-mediated pathways and placental cell functions as well as their implications for pregnancy outcomes. Findings presented herein underscore the need for further research into the effects of exposure to environmental chemicals on modulating EGFR signaling pathways in the context of placental health.

Integrating scRNA-seq to explore offspring neurodevelopmental toxicity induced by Cyfluthrin exposure during pregnancy: A fate decision for NSCs

Cyfluthrin is a widely used insecticide, and studies have shown that its exposure during pregnancy is associated with neurobehavioral abnormalities in offspring, but the mechanism of toxicity is unknown. In this study, we observed the neurodevelopmental toxicity of Cyfluthrin in rat offspring of different ages due to pregnancy exposure, which manifested a series of impairments such as persistent cognitive impairment, neuronal loss in hippocampal tissues, synaptic damage, and altered expression of neurodevelopmental-related factors. Hippocampal scRNA-seq in neonatal rats showed specific cellular responses to prenatal Cyfluthrin exposure. Through DEG intergroup difference analysis, intercellular communication analysis, and mimetic timing analysis, we found that the change in the fate of neural stem cells - alterations in differentiation direction, proliferation, and apoptosis levels - was the main cause of the offspring's developmental toxicity induced by prenatal Cyfluthrin exposure. This inference was verified by our in - vivo and ex - vivo experiments. Our study first constructed a single - cell atlas of the offspring's brain hippocampus exposed to Cyfluthrin during pregnancy. It warns about pesticide intake during pregnancy and nursing in women and provides a theoretical basis for neurodevelopmental toxicity from early - life exposure to environmental pollutants.

Bisphenol analogs exposure in 4-year-old children and their intelligence quotient at 6 years: A prospective cohort study

Prenatal exposure to bisphenol A (BPA) has been shown to impact offspring cognition, behavior, and intelligence. However, whether co-exposure to bisphenol analogs (BPs) during childhood affects children's intelligence remains unclear. We included 465 mother-child pairs from the Shanghai Minhang Birth Cohort Study to examine the impact of children's exposure to BPs at 4 years of age on the intelligence quotient (IQ) measured at 6 years. BPs concentrations were measured in single-spot urine samples collected from 4-year-old children. The Wechsler Intelligence Scale for Children was used to evaluate IQ at 6 years. Multiple linear regression models were used to examine the associations between BPs and IQ. Bayesian Kernel Machine Regression (BKMR) models were used to evaluate the joint and single-exposure effects of BPs mixture. In girls, exposure to bisphenol F (BPF) was inversely associated with Full-Scale IQ (FSIQ) and Perceptual Reasoning Index (PRI) (βFSIQ = -5.46, 95 % confidence interval [CI]: -9.97, -0.94; βPRI = -5.14, 95 % CI: -9.95, -0.32). By BKMR, BPF contributed the most to the joint effect of BPs in girls. The association remained robust after adjusting for maternal IQ. In boys, exposure to tetrachlorobisphenol A seemed to be associated with an increase in FSIQ and PRI; however, the number of exposed boys was small. Our study suggests that BPs exposure at 4 years of age may be associated with a lower IQ at 6 years in girls. BPF may not be a safe substitute for BPA. Further epidemiological studies are required to confirm these findings.

Perinatal Bisphenol Exposure and Small-for-Gestational-Age Neonates: The Evolving Effect of Replacements Then and Now

Bisphenol analogues have been shown to have similar estrogenic activity to that of BPA and may affect fetal development. However, no human studies have examined the effects of perinatal exposure to emerging bisphenol alternatives [bisphenol G, bisphenol M, and bisphenol BP (BPBP)] on small for gestational age (SGA) and how placental function may mediate the relationship. Here, 13 urinary bisphenol analogues were detected in 1054 contemporary pregnant women, and BPA was still the most dominant congener. Logistic regressions identified BPA and its traditional alternatives [bisphenol B (BPB), bisphenol E (BPE), bisphenol Z, and bisphenol AP (BPAP)] as being associated with an elevated risk of SGA (all ORs > 1.80, P < 0.05). In contrast, the emerging substitutes, despite high occurrences, all showed much attenuated risk. Mixture effect models Bayesian kernel machine regression and quantile-based g-computation demonstrated that coexposure to bisphenols was strongly correlated with SGA risk (OR = 2.70, P < 0.001), with BPA and the conventional substitutes (BPB, BPE, and BPAP) as primary effect drivers, outweighing the effect from emerging substitutes. Finally, mediation analysis revealed that the placental function index estriol mediated the relationship between exposure and SGA, dominated by BPBP (25.4%). Our findings provide new epidemiological evidence that early BPA alternatives may pose a higher risk for offspring development than those emerging alternatives, potentially via mediation by compromised placental function. Future toxicity assessments and validation studies in other settings on these emerging bisphenols are needed.

Developmental exposure to an environmentally relevant dose of Bisphenol S impairs postnatal growth and disrupts placental transcriptional profile in female rat

Because of its possible adverse effects on human health and its ubiquitous nature, Bisphenol A (BPA) is gradually being replaced by presumably safer alternatives like Bisphenol S (BPS). However, data regarding the effects of developmental exposure to BPS on pregnancy and fetal outcomes are very scarce. Here we show that perinatal exposure to BPS at a very low dose significantly impairs postnatal growth and affects the placental transcriptome in rats. Oral exposure one week before mating and during gestation and lactation to a very low dose of BPS (25 ng/kg/day) is associated with impaired postnatal growth without significant difference in fetal weight on gestational day 18 in females. In contrast, in males, exposure to BPS 25 decreased fetal weight on gestational day 18 but growth restriction did not persist into adulthood. In female, exposure to this very low dose of BPS decreased the placental mRNA expression of fucosyltransferase2 (Fut2), pregnancy-specific glycoprotein 22 (Psg22), Wnt family member 7b (Wnt7b) which are involved in early placental development. Placental DNA methylation of steroid receptor coactivator 2 (src2), a key mediator of steroid induced decidualization, was significantly reduced, while placental src2 mRNA expression was unaffected. These results suggest that early exposure to a very low dose of BPS has long term consequences on growth trajectory and is associated with placental dysregulation.

The Ovary as a Target Organ for New Generation Bisphenols Toxicity

Bisphenols (BPs) are a group of organic compounds used extensively in plastics, coatings, and epoxy resins; they have been of concern recently due to their endocrine-disrupting effects. Among these, bisphenol A (BPA) is the most studied. Regulatory measures, such as the ban on BPA use in baby bottles by the European Union and its restricted use in thermal paper, reflect the growing awareness of the health risks of BPA. To mitigate these risks, analogs such as bisphenol S (BPS), bisphenol F (BPF), and others (BPAF, BPAP, BPB, BPP, BPZ) have been developed as alternatives. Despite their intended safety, these analogs have been detected in environmental media, including indoor dust and thermal receipt paper, as well as in human biological samples. Studies report their presence in urine at levels comparable to BPA, with BPS and BPF found in 78% and 55% of samples, respectively. In addition, BPs have been found in human follicular fluid (FF) at concentrations that could exert some paracrine effects on ovarian function and reproductive health. With the increased global production of BPs, occupational exposure and environmental contamination also increase. This review summarizes what is currently known about the effects of BPs on the ovary and the mechanisms by which PBs exert ovarian toxicity, with a particular focus on oogenesis, folliculogenesis, and steroidogenesis. Further, this review emphasizes their influence on reproductive functions and the need for further biosafety evaluations.

Prenatal exposure to bisphenol A causes reproductive damage in F1 male rabbits due to inflammation and oxidative stress

Bisphenol A (BPA) is used extensively in producing industrial chemicals such as plastic products, resin, and paper coatings. Concerns have been expressed regarding its possible detrimental consequences, especially on the reproductive system of mammals. Despite extensive study in this domain, there has been no targeted examination of the impact of BPA on F1 generation rabbits. BPA exposure model was developed in pregnant female rabbits to examine the effects of BPA on reproductive hormones, cellular apoptosis, oxidative stress, inflammatory response, and tissue integrity in weaning rabbits. The results indicated that BPA exposure triggered an inflammatory response and oxidative stress, consequently impacting the reproductive system of weaned rabbits and altering reproductive hormone levels. By modulation of the Nrf2 and NF-κB axes, BPA could influence the expression of antioxidant enzymes and inflammatory mediators in the rabbit reproductive system, leading to cell apoptosis and tissue damage. These results underscore the importance of monitoring BPA exposure during pregnancy and emphasize the necessity of implementing measures to mitigate its potential effects on the reproductive health of offspring.

Increased maternal urinary bisphenol F levels associated with reduced anogenital distance in male newborns

BACKGROUND

Bisphenol exposure during pregnancy has been linked to a range of adverse reproductive outcomes. However, the full extent of the effects of bisphenol analogs, particularly bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF), on fetal development, especially anogenital distance (AGD), a sensitive marker of reproductive development, remains unclear. We conducted this research to investigate association among maternal and neonatal urinary bisphenol analogs (BPA, BPS, BPF) and AGD.

METHODS

This prospective cohort study enrolled 85 mother-newborn pairs in Bangkok, Thailand, from April 2023 to January 2024. Maternal and neonatal urine samples were collected and analyzed for BPA, BPF, and BPS concentrations by liquid chromatography-tandem mass spectrometry. Neonatal AGD measurements were obtained within 72 h of birth. Correlation was analyzed by Pearson's correlation test and linear regression analysis.

RESULTS

High maternal urinary BPF concentrations were negatively associated with ano-penile distance, ano-scrotal distance, and penile length in male newborns (r -0.963, -0.844 and - 0.900, respectively, p < 0.05). No significant associations were found for BPA or BPS. Frequent maternal consumption of carton drinks was associated with higher neonatal BPS levels, while maternal obesity was positively correlated with maternal BPA concentration. No significant correlation was observed between maternal and neonatal bisphenol concentrations, nor between neonatal bisphenol levels and AGD.

CONCLUSIONS

This study is the first to report a negative association between maternal BPF exposure and AGD in male newborns. These findings highlight the potential endocrine-disrupting effects of BPF on fetal development and emphasize the need for further research.

Comprehensive Investigation of Epoxy Adhesives for Structural Applications in Saudi Arabia: Mechanical Performance, Environmental Impacts, and Analysis on Health

Epoxy adhesives possess excellent mechanical properties, durability, and stability in harsh environments, making them suitable for producing engineering materials. This study selects four commercially available epoxy adhesives in Saudi Arabia: Epotec YD 128; Sikadur®-52 LP; Sikadur®-31 CF; and Sikadur®-42 MP Slow. Firstly, a comparison of their storage, application, and service temperatures was made, detailing the hazard identification and prevention measures established in accordance with the Occupational Safety and Health Administration (OSHA) guidelines. Subsequently, test samples of the four adhesives were produced, and tensile, compressive, and shear tests were conducted to compare their fundamental mechanical properties. Finally, a gas analyzer assessed the major harmful gases emitted by these epoxy adhesives 120 min after mixing the epoxy resins and curing agents. The results show that Sika 42 exhibits the highest tensile and compressive strengths among other types of adhesives, reaching 75.7 MPa and 133.8 MPa, respectively. It also has the longest pot life of 48 min at elevated temperatures (40 °C), making it suitable for the climatic conditions in Saudi Arabia. However, as a three-component adhesive, its application is complex and associated with the most identified hazards. Sika 31 presents a tensile modulus of up to 10.4 GPa, at least 3.8 times higher than the other adhesives, making it practical for controlling tensile deformation. Additionally, its ultimate shear strain reaches 10.7%, at least 6.6 times higher than the other samples, highlighting its suitability for constructing ductile bonds. After mixing of epoxy resins with curing agents, the presence of NO2 and SO2 were detected. However, no harmful gases were detected after 120 min, possibly due to the complete curing of the adhesives.

Effect of thyroid disruption on ovarian development following maternal exposure to Bisphenol S

Thyroid hormones play a crucial role in numerous physiological processes, including reproduction. Bisphenol S (BPS) is a structural analog of Bisphenol A known for its toxic effects. Interference of this substitute with normal thyroid function has been described. To investigate the effect of thyroid disruption on ovarian development following maternal exposure to BPS, female rats were exposed, daily, to either AT 1-850 (a thyroid hormone receptor antagonist) (10 nmol/rat) or BPS (0.2 mg/kg) during gestation and lactation. The effects on reproductive outcome, offspring development, histological structures, hormone levels, oxidative status, cytoskeleton proteins expression, and oocyte development gene expression were examined. Our results are in favor of offspring ovarian development disruption due to thyroid disturbance in adult pregnant females. During both fetal and postnatal stages, BPS considerably altered the histological structure of the thyroid tissue as well as oocyte and follicular development, which led to premature ovarian failure and stimulation of oocyte atresia, being accompanied with oxidative stress, hypothalamic-pituitary-ovarian axis disorders, and cytoskeletal dynamic disturbance. Crucially, our study underscores that BPS may induce reproductive toxicity by blocking nuclear thyroid hormone receptors, evidenced by the parallelism and the perfect meshing between the data obtained following exposure to AT 1-850 and those after the treatment by this substitute.

Maternal concentrations of environmental phenols during early pregnancy and behavioral problems in children aged 4 years from the Shanghai Birth Cohort

BACKGROUND

Prenatal exposure to environmental phenols such as bisphenol (BPs), paraben (PBs), benzophenone (BzPs), and triclosan (TCS) is ubiquitous and occurs in mixtures. Although some of them have been suspected to impact child behavioral development, evidence is still insufficient, and their mixed effects remain unclear.

OBJECTIVES

To explore the association of prenatal exposure to multiple phenols with child behavioral problems.

METHOD

In a sample of 600 mother-child pairs from the Shanghai Birth Cohort, we quantified 18 phenols (6 PBs, 7 BPs, 4 BzPs, and TCS) in urine samples collected during early pregnancy. Parent-reported Strengths and Difficulties Questionnaires were utilized to evaluate child behavioral difficulties across four subscales, namely conduct, hyperactivity/inattention, emotion, and peer relationship problems, at 4 years of age. Multivariable linear regression was conducted to estimate the relationships between single phenolic compounds and behavioral problems. Additionally, weighted quantile sum (WQS) regression was employed to examine the overall effects of the phenol mixture. Sex-stratified analyses were also performed.

RESULTS

Our population was extensively exposed to 10 phenols (direction rates >50 %), with low median concentrations (1.00 × 10-3-6.89 ng/mL). Among them, single chemical analyses revealed that 2,4-dihydroxy benzophenone (BP1), TCS, and methyl 4-hydroxybenzoate (MeP) were associated with increased behavior problems, including hyperactivity/inattention (BP1: β = 0.16; 95 % confidence interval [CI]: 0.04, 0.30), emotional problems (BP1: β = 0.11; 95 % CI: 0.02, 0.20; TCS: β = 0.08; 95 % CI: 0.02, 0.14), and peer problems (MeP: β = 0.10; 95 % CI: 0.02, 0.18); however, we did not identify any significant association with conduct problems. Further phenol mixture analyses in the WQS model yielded similar results. Stratification for child sex showed stronger positive associations in boys.

CONCLUSION

Our findings indicated that maternal phenol levels during early pregnancy, specifically BP1, TCS, and MeP, are associated with high behavioral problem scores in 4-year-old children.

Bisphenol Z exposure inhibits oocyte meiotic maturation by rupturing mitochondrial function

The use of bisphenol A (BPA) has been restricted due to its endocrine-disrupting effects. As a widely used alternative to BPA today, environmental levels of bisphenol Z (BPZ) continue to rise and accumulate in humans. Oocyte quality is critical for a successful pregnancy. Nevertheless, the toxic impacts of BPZ on the maturation of mammalian oocytes remain unexplored. Therefore, the impacts of BPZ and BPA on oocyte meiotic maturation were compared in an in vitro mouse oocyte culture model. Exposure to 150 μM of both BPZ and BPA disrupted the assembly of the meiotic spindle and the alignment of chromosomes, and BPZ exerted stronger toxicological effects than BPA. Furthermore, BPZ resulted in aberrant expression of F-actin, preventing the formation of the actin cap. Mechanistically, BPZ exposure disrupted the mitochondrial localization pattern, reduced mitochondrial membrane potential and ATP content, leading to impaired mitochondrial function. Further studies revealed that BPZ exposure resulted in oxidative stress and altered expression of genes associated with anti-oxidative stress. Moreover, BPZ induced severe DNA damage and triggered early apoptosis in oocytes, accompanied by impaired lysosomal function. Overall, the data in this study suggest that BPZ is not a safe alternative to BPA. BPZ can trigger early apoptosis by affecting mitochondrial function and causing oxidative stress and DNA damage in oocytes. These processes disrupt cytoskeletal assembly, arrest the cell cycle, and ultimately inhibit oocyte meiotic maturation.

Cyfluthrin exposure during pregnancy causes neurotoxicity in offspring-Ca2+ overload via IP3R-GRP75-VDAC1 pathway

Cyfluthrin (Cy) is a widely used pyrethroid insecticide. There is growing evidence that Cy can cause damage to the nervous, reproductive, and immune systems, but there is limited evidence on the potential effects of maternal Cy exposure on offspring. A model of maternal Cy exposure was used to assess its neurobehavioral effects on young-adult offspring. We found that gestational Cy exposure affected pregnancy outcomes and fetal development, and that offspring showed impairments in anxiety as well as learning and memory, accompanied by impairments in hippocampal synaptic ultrastructure and synaptic plasticity. In addition, the IP3R-GRP75-VDAC1 apoptogenic pathway was also upregulated, and in vitro models showed that inhibition of this pathway alleviated neuronal apoptosis as well as synaptic plasticity damage. In conclusion, maternal Cy exposure during pregnancy can cause neurobehavioral abnormalities and synaptic damage in offspring, which may be related to neuronal apoptosis induced by activation of the IP3R-GRP75-VDAC1 pathway in the hippocampus of offspring. Our findings provide clues to understand the neurotoxicity mechanism of maternal Cy exposure to offspring during pregnancy.