A new chapter in the bisphenol A story: bisphenol S and bisphenol F are not safe alternatives to this compound

Bisphenol-A-induced ovarian cancer: Changes in epithelial diversity, apoptosis, antioxidant and anti-inflammatory mechanisms

This research was designed to study the carcinogenic mechanisms of BPA on ovarian epithelial cells. For four months, mice were treated with low (LD, 1 mg/kg) and high (HD, 5 mg/kg of body weight) doses of BPA on alternate days through oral gavage; the control group was given corn oil through gavaging during 4 months. The histopathological data suggest that repeated BPA administration induces a borderline epithelial neoplasm with altered epithelial morphology with branching papillae. Various epithelial cells (ECs) in ovaries were identified by flow cytometry based on anti-mouse CD74 and podoplanin (PDPL) receptors expression. Three different populations of ovarian epithelial cells were identified: epithelial cells type 1 (PDPL+CD74-,EC1), epithelial cells type 2 (PDPL-CD74+, EC2), and transition epithelial cells (PDPL+CD74+, TEC). The EC1 decreased, but EC2 was increased in BPA-exposed mice. The population of TEC was comparable to that in the control group at the low dose (LD) but decreased in the high dose (HD) BPA-treated groups. A significant increase in PDPL, CD74 receptor expression and apoptosis and necrosis in BPA-treated ovarian cells was seen. The RT-qPCR results suggest that the relative expression levels of pro-apoptotic (Bax and Casp3) and anti-apoptotic Cytc were markedly decreased, but Bcl2 expression was increased. The anti-inflammatory (IFN-γ, TNF-α, TGF-β, IL-6) gene expression was reduced, but NF-kB expression was increased. Hypoxia regulator (Hif-1α and Nrf2) and tumour suppressor genes (p53 and p21) were also decreased. Thus, BPA exposure changes EC diversity, induces mortality and alters antioxidant, apoptotic and inflammatory gene expression in ovary.

Clustering of bisphenols based on toxicity predictions for key aquatic species: Daphnia magna, Pimephales promelas, and Oryzias latipes

The in silico assessment of chemical toxicity is crucial for regulatory frameworks like REACH, which support the use of QSAR models and read-across techniques to predict the properties of compounds. This study addresses the challenge of evaluating bisphenol A (BPA) alternatives, for which specific predictive models are often lacking. Utilizing VEGA software, we examined three ecotoxicological endpoints: toxicity in Daphnia magna (Daphnia magna Acute (EC50) Toxicity model (IRFMN)), Pimephales promelas (Fathead Minnow LC50 96 h toxicity (EPA)), and Oryzias latipes (Fish Acute (LC50) toxicity model (IRFMN)). We employed Self-Organizing Maps (SOM) to cluster bisphenol compounds based on similarities to experimental data from model training sets. Principal Component Analysis (PCA) was used to reduce dimensionality and visualize data, with color-coding to indicate predicted properties. Our results reveal that while BPA is often a cluster indicator due to its extensive inclusion in training sets, BPA alternatives frequently exhibit similar toxicological concerns. The clustering approach provides a nuanced understanding of the potential risks associated with BPA alternatives, suggesting that many may not offer significant safety improvements over BPA itself.

Repeated measurements of urinary bisphenol A and its analogues in relation to sperm DNA damage

Bisphenol A (BPA), a common endocrine disrupting chemical (EDC), has shown detrimental effects on sperm quality and function in experimental models. However, epidemiological evidence is inconsistent and also there exists a notable lack of data on its analogues, such as bisphenol F (BPF) and bisphenol S (BPS). To investigate the relationships between BPA, BPF and BPS exposures and sperm DNA damage, we conducted a cross-sectional study recruiting 474 Chinese men from an infertility clinic in Wuhan, China. We repeated measurements of urinary BPA, BPF and BPS concentrations to enhance the exposure assessments and evaluated sperm DNA damage using three comet assay indicators: tail length (TL), tail distributed moment (TDM) and percentages of tail DNA (Tail%). We observed positive associations of BPA exposure with TL and TDM (both P for trends < 0.05) and an association of elevated BPF exposure with increased Tail% (P for trend = 0.066). Furthermore, BPA exposure in relation to increased TL and TDM were more pronounced in men with body mass index (BMI) below 24 kg/m2 and non-smokers (all P for interactions < 0.05). Our findings strengthened human evidence that BPA and its analogue BPF exposures were in relation to increased sperm DNA damage.

Chronic exposure to bisphenol S is associated with antagonistic neurobehavioral transformation and cleaved caspase 3 induced neurodegeneration in zebrafish brain

Bisphenol S (BPS), a widely used bisphenol analogue, has been increasingly detected in aquatic environments, raising concerns about its potential neurotoxic effects. However, the mechanism underlying the neurotoxicity induced by BPS remains elusive. In this context, our present study was aimed to investigate the impact of temporal BPS exposure towards precocious development of neurobehavioral transformation and neurodegeneration in zebrafish brain. Heightened monoamine oxidase (MAO) activity is associated with induction of aggressive behavioural response. In line with earlier report, our findings following mirror biting test advocated that temporal BPS exposure is associated with gradual genesis of aggressive neurobehavioral response and is correlated with augmented MAO activity and downregulation of tyrosine hydroxylase (TH) expression in zebrafish brain. Our further observation towards native neurobehavioral response as regulated by periventricular grey zone (PGZ) of optic tectum (TeO) of brain showed that duration dependent exposure to BPS is associated with gross transformation in scototaxis and explorative behaviour of zebrafish. Concurrently, our objective was also predestined to emphasize the detrimental effect of BPS on brain biochemistry and neuromorphology. In this line, our findings showed that BPS-persuaded heightened oxidative stress is linked with augmented chromatin condensation and apoptotic cell death as depicted through cleaved caspase-3 expression in zebrafish brain. To understand neuromorphological integrity of PGZ region through expression of NeuN, our findings advocated a significant downregulation following temporal exposure to BPS. In a nutshell, the gross observation delineates the strong neurodegenerative potential of BPS coupled through neurobehavioral transformation, oxidative stress and neuromorphological alteration in zebrafish brain.

Perinatal exposure to bisphenol A or S alters differently sexual behavior and kisspeptin system in mice

The effects of bisphenol A (BPA), a highly diffused endocrine-disrupting chemical found mainly in plastics, on neural circuits and behaviors are well-known. However, the effects of its substitutes have not been fully investigated. Thus, in the present study, we compare the effects of perinatal exposure to bisphenol A or S (BPS) on reproductive behaviors and related hypothalamic kisspeptin system in mice. C57BL/6J dams were orally treated with 4 μg/kg body weight/day of BPA, BPS, or vehicle from mating until the weaning of the offspring. In the adult offspring, we performed the two-bedding T-Maze test, and we observed the spontaneous sexual behavior. Exposure to BPA caused a delay in puberty onset in females, while BPS caused anticipation in males, and both altered the estrous cycle in females. The sexual and sexual-related behaviors were partially altered in males, especially in the BPA-exposed ones. Regarding the kisspeptin immunoreactivity in the analyzed hypothalamic nuclei, in BPA- or BPS-treated females, we observed an increase within the rostral periventricular area, while BPA led to an increase in the paraventricular nucleus, and BPS induced a reduction compared to control females. Among males, we observed a significant increase in the arcuate nucleus of BPA-treated males and a significant decrease in the paraventricular nucleus of BPS-treated ones. These results support the idea that perinatal exposure to low doses of either BPA or BPS is altering, in a sexually differentiated way, some reproductive-relevant parameters, sexual behaviors, and kisspeptin hypothalamic nuclei.

Biodegradation of Xenoestrogens by the Green Tide Forming Seaweed Ulva: A Model System for Bioremediation

Anthropogenic xenoestrogens pose serious threats to humans and the environment. Ulva (Chlorophyta), a green macroalga that can propagate in environments of various salinities, is a potential candidate for efficient wastewater treatment and bioremediation. In this study, we tested the class of bisphenols and ethinylestradiol and investigated the underlying removal mechanisms of these xenoestrogens. The model organism Ulva mutabilis demonstrated over 99% removal efficiency for bisphenols A, B, E, F, P, and Z, and partial removal of bisphenol S. Ulva showed complete removal capabilities even under axenic conditions, while its associated bacteria were not involved. Complete removal of 6.6 mg L-1 of bisphenol A was achieved within 2 days and a half-time of 1.85 h. Biodegradation was the leading cause of removal, whereas bioaccumulation was minimal. The model substance bisphenol A underwent various reactions, and 20 transformation products were detected using stable isotope labeling. While most of the bisphenol A was completely biodegraded, the primary transformation products were monobromobisphenol A, bisphenol A bisulfate, and 4-hydroxypropanylphenol. This study highlights the potential of the green seaweed Ulva to provide a pathway for more effective and sustainable bioremediation strategies to tackle the environmental pollution caused by xenoestrogens.

The deleterious effect of bisphenol S on early embryo development of mice

PURPOSE

Increasing levels of infertility in Western countries has drawn ever more scientific attention to the role in this trend of endocrine disruptors, such as bisphenol A, a substance now banned in some cases and some countries. Because this substance has been replaced by the structurally similar bisphenol S (BPS), this study focused on the effects of the latter on early mice embryo development.

METHODS

Cultures of CD1 mice embryos with varying concentrations of BPS were compared with control blank cultures in order to examine the survival rate of embryos according to BPS concentration and culture day.

RESULTS

The administration of BPS at any dose (1, 10, and 100 pg/ml) in cultures of mice embryos led to a significant decrease in their survival rate. The negative effect of BPS was seen to start early (day 1 of experiment), even with the lowest employed dose (1 pg/ml).

CONCLUSIONS

This is, to the best of our knowledge, the first study to investigate the impact of BPS on the survival rate of mice embryos. In this study, potential adverse effects of BPS on early CD1 mice embryo development with regard to survival rate have been identified. Dose of BPS, timing of BPS administration, and time duration of exposure play a critical role in the decrease of mice embryo survival rate as compared to control cultures. These findings raise concerns regarding the safety of BPS and highlight the need for further research into the effect of this substance on human embryos.

Bisphenol F (BPF) exposure impairs sperm quality and offspring development in male zebrafish

BACKGROUND

Bisphenol F (BPF), a substitute for bisphenol A (BPA), is widely used in consumer products, increasing the potential for environmental exposure. Our study investigated the reproductive effects of BPF on adult male zebrafish and explored its toxicological mechanisms, as well as its intergenerational effects.

METHODS

Adult male zebrafish were exposed to BPF concentrations of 0, 50, 500, 2500, and 5000 nM for 21 days. We evaluated sperm cell quantity and quality, hormonal markers testosterone (T) and vitellogenin (VTG), gene expression profiles related to hormone synthesis, metabolism, apoptosis, cell cycle, sexual behavior, and offspring health metrics including survival, development and locomotion.

RESULTS

BPF exposure did not significantly affect body weight or gonadal index. However, at 500 and 2500 nM, a significant reduction in sperm count was observed. BPF exposure led to decreased serum T and increased hepatic VTG levels, indicating hormonal disruption. At 50 nM, BPF initiated sperm apoptosis, and at higher doses, it disrupted sperm meiosis, affecting cell distribution. This exposure negatively impacted sperm quality, reduced offspring survival rates, and altered sperm motility in adult fish. Offspring from BPF-exposed groups showed developmental issues, including increased mortality, delayed developmental stages, abnormal tail coiling and heart rate, which correlated with paternal sperm count and quality changes, alterations in T and VTG levels, and cell cycle phase distributions.

CONCLUSIONS

Our study demonstrated that BPF exposure significantly impacted sperm quality, characterized by reduced sperm count and altered motility patterns, leading to developmental anomalies in offspring. These novel findings highlight the need for further research into BPF's reproductive and developmental toxicity, emphasizing the potential risks to aquatic ecosystems and human health. The observed effects on sperm quality, hormonal balance, and offspring development provide new insights into the reproductive toxicity profile of BPF.

Exposure to bisphenol S induces organ toxicity by disrupting oxidative and antioxidant defense system and blood physiology in Labeo rohita (Hamilton, 1822)

Bisphenol S is an emerging pollutant that is contaminating aquatic ecosystems and causing detrimental effects on aquatic organisms, especially fish. Therefore, the study was designed to evaluate the toxicity of bisphenol S (BPS) through genotoxic, biochemical, histopathological, and oxidative damage in the liver, gills, and kidneys of Labeo rohita fish. Fish were exposed to three different concentrations (400 µg/L, 800 µg/L, and 1000 µg/L) of BPS for 21 days. A significant (p ≤ 0.05) decline in antioxidant enzymatic activity of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and peroxidase (POD) was observed in all tissues, whereas elevation in oxidative contents (TBARS and ROS) was observed. Comet analysis showed elevated olive tail moment and % of DNA damage. Light microscopy revealed several anomalies including cluster nuclei formation, damaged parenchyma cells, sinusoidal spaces, and melanomacrophage in the kidney, sinusoidal spaces, dilated hepatic vein, pyknotic nuclei, melanomacrophage, and cell necrosis in the liver and bone cell deformities, lamellar aneurysm, hyperplasia, and curved secondary gill lamellae in gills. Results of hematobiochemical analysis revealed a significant (p ≤ 0.05) increment in hematocrit, WBCs, cholesterol, blood glucose, triglycerides, AST, ALT, T3, TSH, T4, urea, and creatinine, whereas decline in RBCs, MCH, hemoglobin, proteins levels was observed. The results of the current study demonstrate that BPS has detrimental effects on the kidneys, gills, and liver. It interferes with normal functioning by inhibiting enzymatic activity, causing DNA damage, and disrupting the normal structure of vital organs. These effects make BPS toxic to fish, even at low concentrations.

Effect of bisphenol F on reproductive function in F1 generation male mice and its potential mechanisms

Bisphenol F (BPF) is an environmental endocrine disruptor capable of crossing the placental barrier and affecting the growth and development of offspring. Despite its potential impact, systematic research about effects of BPF on the reproductive function of male offspring remains limited. In this study, pregnant female mice were exposed to BPF at doses of 40, 400, and 4000 μg/kg during gestation and lactation, respectively, to evaluate its impact on testicular damage, testosterone levels, and spermatogenesis of male offspring (F1 generation), and further explore the mechanisms using transcriptomics. First, the study demonstrated that BPF induces testicular damage in F1 generation mice, leading to decreased testosterone levels and sperm quality. Second, transcriptomic analysis revealed that BPF affected spermatogenesis in F1 generation mice by disrupting retinol metabolism. Third, transcriptomic analysis revealed that BPF reduce the capacity for testosterone synthesis in F1 generation mice by diverting the testosterone precursor dehydroepiandrosterone (DHEA) towards the synthesis of 16α-hydroxydehydroepiandrosterone rather than testosterone. Finally, it was confirmed that BPF hinder cholesterol transport to mitochondria by inhibiting the cAMP signaling pathway, thereby impacting testosterone synthesis. In summary, the results of this study suggest that gestational exposure to BPF can lead to reproductive dysfunction in F1 generation male mice.

Damage mechanisms of bisphenols on the quality of mammalian oocytes

The extensive use of bisphenols in the plastics industry globally is a major growing concern for human health. Bisphenol compounds are easily leached out from plastic containers to food, beverages, and drinking water and contaminate the natural environment. Daily exposure of bisphenol compounds increases their load and impairs various organs, including the reproductive system. Bisphenol compounds directly or indirectly affect ovarian functions, such as folliculogenesis, steroidogenesis, oogenesis, and thereby oocyte quality. Bisphenol A (BPA) and its structural analogues act as endocrine disruptors and induce generation of reactive oxygen species (ROS) within the ovary. Excess levels of ROS induce death pathways in follicular steroidogenic cells and affect ovarian steroidogenesis. The reduced level of estradiol-17β impairs follicular growth and development that reduces the number and quality of oocytes. In addition, excess levels of ROS in follicular fluid trigger meiotic instability, which further deteriorates oocyte quality. The high level of ROS generates oxidative stress that triggers various death pathways in germ cells as well as in oocytes, induces follicular atresia, and depletes ovarian reserve. Although growing evidence indicates the destructive effects of bisphenol compounds at the level of ovary, potential effects and underlying mechanisms that deteriorate oocyte quality remain poorly understood. Therefore, this review summarizes the mechanisms by which bisphenols cause damage to the ovary, impair oocyte quality, and affect women's fertility.

Assessment of bisphenol accumulation from disposable devices used sequentially in IVF routine procedures

RESEARCH QUESTION

Are bisphenols released from disposable devices used in assisted reproductive technology (ART) procedures, and do they accumulate when several disposable devices are used sequentially under routine conditions?

DESIGN

A comprehensive assessment of 19 individual disposable devices (31 assessments) and nine combinations of disposable devices replicating the main steps in an ART procedure was undertaken. The extraction of bisphenols followed routine-use conditions (temperature and duration). The concentrations of 10 bisphenols were determined using online solid-phase extraction/liquid chromatography/mass spectrometry methodology.

RESULTS

Bisphenol S (BPS) was quantified consistently from 100-mm culture dishes (32 ± 20 pg) and from high security sperm straws (3 ± 1 pg). Also, BPS and bisphenol A (BPA) were quantified consistently from spermicide-free condoms (95 ± 78 and 83 ± 49 pg, respectively). No other bisphenols were detected in disposable devices when tested individually. When disposable devices were used in combination, both BPA and BPS were detected consistently in combinations of 13 disposable devices mimicking sperm collection in a condom and its preparation (46 ± 16 and 43 ± 32 pg, respectively). BPS was quantified consistently in combinations of 14 disposable devices mimicking sperm collection, its preparation and freezing (10 ± 4 pg), and in combinations of 17 disposable devices mimicking oocyte retrieval (37 ± 22 pg).

CONCLUSIONS

BPA and BPS are released in small quantities from some disposable devices used in routine conditions during ART procedures, but do not appear to accumulate when these disposable devices are used in combination.

Toxicological effects of bisphenol F on growth, antioxidant response, ultrastructure, and microbial properties of the submerged macrophyte Ceratophyllum demersum L

Alternative chemicals to bisphenol A (BPA), such as bisphenol F (BPF), have been detected in aquatic environments worldwide and can potentially exert negative effects on aquatic organisms. To evaluate the toxic effects of the exposure of BPF on submerged macrophytes and biofilms, Ceratophyllum demersum L. (C. demersum) was exposed to different concentrations of BPF (1, 5, 10, and 20 mg L-1). In general, the growth of C. demersum was inhibited, and the chlorophyll content of C. demersum noticeably decreased at high concentrations of BPF (20 mg L-1). In addition, different concentrations of exposure to BPF induced a certain degree of oxidative stress, as evidenced by increased the activities of superoxide dismutase, catalase, and peroxidase, as well as increased malondialdehyde concentrations. Furthermore, the scanning electron microscopy results and high-throughput sequencing analysis showed the diversity and structure of the microbial community were altered on the leaf biofilms in the presence of BPF. In addition, the leaf cells of C. demersum showed some damage and variation of organelles and membranes when examined by transmission electron microscopy. The current study is the first to assess the effects of BPF on the physiological and biochemical of C. demersum, these results suggest the understanding of how submerged macrophyte and leaf biofilms respond to environmental stress induced by BPF.

The impact of Bisphenol-A on human reproductive health

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

Impact of Bisphenol A and its alternatives on oocyte health: a scoping review

BACKGROUND

Bisphenol A (BPA) is an endocrine disrupting chemical released from plastic materials, including food packaging and dental sealants, persisting in the environment and ubiquitously contaminating ecosystems and human populations. BPA can elicit an array of damaging health effects and, alarmingly, 'BPA-free' alternatives mirror these harmful effects. Bisphenol exposure can negatively impact female fertility, damaging both the ovary and oocytes therein. Such damage can diminish reproductive capacity, pregnancy success, and offspring health. Despite global government regulations in place to indicate 'safe' BPA exposure levels, these policies have not considered the effects of bisphenols on oocyte health.

OBJECTIVE AND RATIONALE

This scoping review was conducted to evaluate evidence on the effects of BPA and BPA alternatives on standardized parameters of oocyte health. In doing so, this review addresses a critical gap in the literature providing a comprehensive, up-to-date synthesis of the effects of bisphenols on oocyte health.

SEARCH METHODS

This scoping review was conducted in accordance with PRISMA guidelines. Four databases, Medline, Embase, Scopus, and Web of Science, were searched twice (23 February 2022 and 1 August 2023) to capture studies assessing mammalian oocyte health post-bisphenol exposure. Search terms regarding oocytes, ovarian follicles, and bisphenols were utilized to identify relevant studies. Manuscripts written in English and reporting the effect of any bisphenol on mammalian oocyte health from all years were included. Parameters for toxicological studies were evaluated, including the number of bisphenol concentrations/doses tested, dosing regimen, biological replicates and/or animal numbers, and statistical information (for human studies). Standardized parameters of oocyte health including follicle counts, oocyte yield, oocyte meiotic capacity, morphology of oocyte and cumulus cells, and oocyte meiotic spindle integrity were extracted across the studies.

OUTCOMES

After screening 3147 studies, 107 studies of either humans or mammalian animal models or humans were included. Of the in vitro exposure studies, 96.3% (26/27) and 94.1% (16/17) found at least one adverse effect on oocyte health using BPA or BPA alternatives (including BHPF, BPAF, BPB, BPF, and BPS), respectively. These included increased meiotic cell cycle arrest, altered morphology, and abnormal meiotic spindle/chromosomal alignment. In vivo, 85.7% (30/35) of studies on BPA and 92.3% (12/13) on BPA alternatives documented adverse effects on follicle development, morphology, or spindle/chromosome alignment. Importantly, these effects were recorded using levels below those deemed 'safe' for human exposure. Over half (11/21) of all human observational studies showed associations between higher urinary BPA levels and reduced antral follicle counts or oocyte yield in IVF patients. Recommendations are presented based on the identified shortcomings of the current evidence, incorporating elements of FDA requirements for future research in the field.

WIDER IMPLICATIONS

These data highlight the detrimental impacts of low-level BPA and BPA alternative exposure, contributing to poor oocyte quality and reduced fertility. These outcomes are valuable in promoting the revision of current policies and guidelines pertaining to BPA exposure internationally. This study serves as a valuable resource to scientists, providing key recommendations on study design, reporting elements, and endpoint measures to strengthen future studies. Ultimately, this review highlights oocyte health as a fundamentally important endpoint in reproductive toxicological studies, indicating an important direction for future research into endocrine disrupting chemicals to improve fertility outcomes.

Neurotoxic effects of perinatal exposure to Bisphenol F on offspring mice

Bisphenols constitute a diverse group of endocrine-disrupting chemicals (EDCs) that impact hormone activity. Bisphenol F (BPF) is commonly used as a substitute for Bisphenol A (BPA). The disruption of the immune system by EDCs during embryonic brain development has been suggested as a plausible factor to neurodevelopmental disorders. We investigated the neurotoxic effects of perinatal exposure to BPF on offspring mice. Female mice were exposed to BPF through their drinking water on day 0.5 of pregnancy, and this exposure continued until the offspring mice were weaned, throughout the perinatal period. Our findings revealed that exposure to BPF hindered both growth and neurodevelopment in offspring mice, with a more pronounced effect observed in males. Additionally, transcriptomic analysis was conducted on the brains of male offspring mice exposed to high doses of BPF. In summary, our study indicates that perinatal exposure to BPF results in neurodevelopmental impairments in male offspring mice, linked to oxidative stress, inflammatory responses, and immune dysregulation. These findings underscore that BPF may not be a safe substitute for BPA. Thus, there is a pressing need to reevaluate the current regulation of BPF.

Urinary profiles of bisphenol S derivatives and their exposure pathway analysis in maternal and infant populations of Beijing

Bisphenol S (BPS) derivatives have potential reproductive developmental toxicity and have been found in the environment and in breast milk. The level of infant exposure and the source are currently unknown. In this study, we investigated BPS and six derivatives (together referred to as BPs) in urine samples from mothers and infants, indoor dust, breast milk and infant formula in Beijing, China. BPS, diphenyl sulfone (DPS) and 4-allyloxy-4'-hydroxydiphenyl sulfone (BPS-MAE) were the main BPs. Notably, the concentration of DPS in infants' urine was higher than that of BPS, which warrants attention. Infants have higher daily intake levels than mothers. Exclusively breastfed infants have a higher risk of BPs exposure than exclusively formula-fed infants. For exclusive breastfed infants, the contribution of individual BPs through breast milk was 23.2% to 93.6%. While for exclusively formula-fed infants, the contribution of individual BPs through infant formula was 30.5% to 70.3%. The contribution of individual BPs through indoor dust was no more than 10%. The results suggesting that infants can be exposed to BPs through other pathways. This is the first comprehensive assessment of maternal and infants exposure to BPS derivatives, providing insights into the sources of infant exposure.

Gene Expression Modulation of Markers Involved in Bone Formation and Resorption by Bisphenol A, Bisphenol F, Bisphenol S, and Bisphenol AF

BACKGROUND

Bisphenol A (BPA) and its analogs (BPF, BPS, and BPAF) are recognized for inducing detrimental effects on various tissues, including bone.

OBJECTIVES

The aim of this study is to investigate their impact on information and repair processes, specifically focusing on vascular endothelial growth factor (VEGF), transforming growth factor β1 (TGF-β1), and the receptors for transforming growth factor β (TGFR1, TGFR2, and TGFR3).

METHODS

Human osteoblasts isolated through primary culture from bone samples of healthy volunteers were subjected to cultivation in the presence of various dosage levels (10-5, 10-6, or 10-7 M) of BPA, BPF, BPS, or BPAF for 24 h. Gene expressions of RANKL, OPG, TGF-β1, TGFR1, TGFR2, TGFR3, and VEGF were analyzed by real-time polymerase chain reaction (RT-PCR). All experiments included untreated cells as controls.

RESULTS

Expressions of RANKL and OPG were dose-dependently downregulated by the presence of all tested bisphenols (BPs) except for BPAF, whose presence upregulated OPG expression at all three doses. TGF-β1 expression was downregulated by all BP treatments, and TGF-β1 receptor expression was also downregulated as a function of the BP and dose. VEGF expression was downregulated in the presence of BPF and BPAF at all three doses and in the presence of BPA at the two higher doses (10-5, and 10-6 M), but it was not changed by the presence of BPS at any dose.

CONCLUSIONS

The inhibition of both RANKL and OPG by the BPs, with a higher %inhibition of RANKL than of OPG, appears to rule out BP-induced activation of osteoclastogenesis via RANKL/RANK/OPG. Nevertheless, the effect of the BPs on the expression by osteoblasts of TGF-β1, TGF-β receptors, and VEGF indicates that these compounds can be responsible for major molecular changes in this cell population, contributing to their adverse effects on bone tissue.

Evaluating the Toxicity Induced by Bisphenol F in Labeo rohita Fish Using Multiple Biomarker Approach

Bisphenol F (BPF) is an emerging contaminant extensively used in the pharmaceutical, chemical, and food industries, exerting deleterious effects on human and wildlife health. Therefore, the current study was conducted to assess the toxicity induced by BPF in rohu Labeo rohita using multiple biomarkers such as oxidative stress, activity of antioxidant enzymes, biochemical parameters, histology, and genotoxicity. Fish were separated into four groups (T1-T4). Group T1 served as a control (0 μg/L), while Groups T2, T3, and T4 were exposed to BPF concentrations of 600 μg/L, 1200 μg/L, and 1800 μg/L, respectively, for 21 days. Results showed a significant (p < 0.05) increase in oxidative biomarkers (thiobarbituric acid reactive substance [TBARS] and reactive oxygen species [ROS]), while the concentration of antioxidant biomarkers (peroxidase [POD], superoxide dismutase [SOD], reduced glutathione [GSH], and catalase) was significantly (p < 0.05) decreased with the rising concentration of BPF in the liver, gills, and kidney of fish. Significant reduction (p < 0.05) in biochemical parameters was measured from collected whole blood, including red blood cells (RBCs), hemoglobin (HGB), mean corpuscular HGB (MCH), MC volume (MCV), hematocrit (HCT), MC HGB concentration (MCHC), platelets, low-density lipoprotein (LDL), cholesterol, high-density lipoprotein (HDL), total proteins, very LDL (VLDL), albumin and globulin, while white blood cells (WBCs), neutrophils, triglycerides, aspartate aminotransferase (AST), blood glucose, and alanine transaminase (ALT) levels were increased significantly (p < 0.05). Comet assay showed the DNA damage potential of BPF in erythrocytes. Histological examination showed that exposure to BPF causes several degenerative effects in the soft tissues (gills, liver, and kidney) of treated fish. It is concluded that BPF induces deleterious effects via disruptions in histological, genotoxic, and biochemical alterations in several organs of exposed fish.

National investigation of bisphenols in the surface soil in China

The long-term production and extensive use have resulted in the widespread presence of bisphenols (BPs) in the environment. In order to clarify the pollution characteristics and potential sources of BPs, the national scale surface soil samples were collected in China in 2019. The results demonstrated that 32 target BPs existed widely in soil with the highest concentration for bisphenol A (BPA), and at least 2 BPs were detected in each sample. The total concentration of Σ32BPs (from 0.387 to 713 ng/g) exhibited a stepwise decrease from southeastern coast to inland regions, and due to the presence of more pollution sources concentrations of Σ32BPs in urban areas were slightly higher than rural areas. The different industrial structures (such as plastics, epoxy resins, and thermal paper) may be the important factors for the different pollution levels between southeastern coast and other regions. In addition, the high organic matter content in soil and low temperature may be the reasons for high concentrations of Σ32BPs in Northeast China. The results of source identification using the Positive Matrix Factorization model indicated that BPs in soil were originated from three sources: old sources represented by BPA, relatively new sources characterized by bisphenol S, and sources from specific industries using bisphenol F. The estimated daily intake indicated that BPA exposure through soil accounted for only a small proportion of the total exposure compared to other exposure routes, and the risk by BPA in soil can be negligible to human health. In summary, the study provided basic pollution information of BPs in Chinese surface soil for future related studies.

Thyroid-disrupting effects of bisphenol S in male Wistar albino rats: Histopathological lesions, follicle cell proliferation and apoptosis, and biochemical changes

In this presented study, the aim was to investigate the toxic effects of bisphenol S (BPS), one of the bisphenol A analogues, on the thyroid glands of male Wistar albino rats. Toward this aim, the rats (n = 28) were given a vehicle (control) or BPS at 3 different doses, comprising 20, 100, and 500 mg/kg of body weight (bw) via oral gavage for 28 days. According to the results, BPS led to numerous histopathological changes in the thyroid tissue. The average proliferation index values among the thyroid follicular cells (TFCs) displayed increases in all of the BPS groups, and significant differences were observed in the BPS-20 and BPS-100 groups. The average apoptotic index values in the TFCs were increased significantly in the BPS-500 group. The serum thyroid-stimulating hormone and serum free thyroxine levels did not show significant changes after exposure to BPS; however, the serum free triiodothyronine levels displayed significant decreases in all 3 of the BPS groups. BPS was determined to cause significant increases in the antioxidant enzyme activities of catalase, superoxide dismutase, glutathione-S-transferase, glutathione peroxidase, as well as a significantly decreased content of reduced glutathione. The malondialdehyde level in the thyroid tissue was elevated significantly in the BPS-500 group. The data obtained herein revealed that BPS has thyroid-disrupting potential based on structural changes, follicle cell responses, and biochemical alterations including a decreased serum free triiodothyronine level and increased oxidative stress.

A multibiomarker approach to assess the effects of a BPA analogue-contaminated diet in the crab Carcinus aestuarii

Bisphenol A analogues are largely used plasticisers that are going to replace bisphenol A in many sectors. Due to this replacement, their discharge and presence in the marine coastal areas are increasing, with unknown consequences for organisms and the trophic chain. This study assessed the effects of three different bisphenols (BPAF, BPF and BPS) - alone or as a mixture - provided via food (exposed clams) to the crab Carcinus aestuarii. First, clams were exposed for two weeks to 300 ng/L of each of the three bisphenols and their mixture (100 ng/L of each) to allow the bioaccumulation of the contaminants in bivalves. Then, crabs were fed for two weeks with BPA analogue-exposed clams, while unexposed clams were used to feed control crabs. After 7 and 14 days, haemolymph, gills and hepatopancreas were collected from crabs to measure a battery of biomarkers indicative of cytotoxicity, oxidative stress and damage, neurotoxicity, physiological performance (respiration and excretion rate) and electron transport system activity. Lastly, bioaccumulation of BPA analogues was assessed by UHPLC-HRMS in crabs. Our findings revealed that BPA analogue-exposed clams were able to alter total haemocyte count, haemocyte size and their proliferation. The activity of immune enzymes, such as phosphatases and phenoloxidase was altered. Moreover, we observed an impairment of antioxidant and detoxifying enzymes like SOD, CAT, GST and GPX activities. Alterations of metabolism-involved enzymes and physiological parameters and increased oxidative damage to macromolecules like proteins, lipids, and DNA were also observed in crabs. Among BPA analogues, only bioaccumulation of BPAF, which has the highest Logkow value among the tested bisphenols, was evidenced in crabs. Overall, the obtained results indicated that crabs, under the tested experimental conditions at least, underwent alterations in cellular, biochemical and physiological responses following a diet of bisphenol-exposed clams, suggesting a potential ecotoxicological risk in the marine food chain.

Mitigating Dietary Bisphenol Exposure Through the Gut Microbiota: The Role of Next-Generation Probiotics in Bacterial Detoxification

Bisphenols, such as bisphenol A and its analogs, which include bisphenol S, bisphenol F, bisphenol AF, and tetramethyl bisphenol F, are chemical contaminants commonly found in food that raise serious health concerns. These xenobiotics can potentially have harmful effects on human health. The gut microbiota plays a crucial role in metabolizing and neutralizing these substances, which is essential for their detoxification and elimination. Probiotic supplementation has been studied for its ability to modulate the gut microbiota's composition and function, enhancing detoxification processes. Next-Generation Probiotics (NGPs) may exhibit better properties than traditional strains and are designed for targeted action on specific conditions, such as obesity. By modulating inflammatory responses and reducing the secretion of pro-inflammatory cytokines, they can significantly improve host health. Research on NGPs' ability to neutralize obesogenic bisphenols remains limited, but their potential makes this a promising area for future exploration. This review aims to understand the mechanisms of the chemical transformation of bisphenol through its interactions with the gut microbiota and the role of probiotics, particularly NGPs, in these processes. Understanding the interplay between bisphenols, gut microbiota, and NGPs may pave the way for strategies to counteract the negative health effects associated with daily and chronic exposure to bisphenols, which is crucial for food safety and consumer health protection.

A computational assay for identifying millet-derived compounds that antagonize the interaction between bisphenols and estrogen-related receptor gamma

The use of Bisphenol A (BPA) and its analogs in industries, as well as the products made from them, is becoming a significant concern for human health. Scientific studies have revealed that BPA functions as an endocrine disruptor. While some analogs of BPA (bisphenols) have been used for a longer time, it was later discovered that they are toxic, similar to BPA. Their widespread use ensures their presence in the environment, and thus, everyone is exposed to them. Scientific research has shown that BPA interacts with estrogen-related receptor gamma (ERRγ), affecting its normal function. ERRγ is involved in biological processes including energy metabolism and mitochondrial function. Therefore, continuous exposure to bisphenols increases the risk of various diseases. In our previous study, we observed that some analogs of BPA had a higher binding affinity to ERRγ compared to BPA itself and analyzed the amino acid residues involved in this interaction. We hypothesized that by antagonizing the interaction between bisphenols and ERRγ, we could neutralize their toxic effects. Taking into account the health benefits of millets and their toxin removal properties, virtual screening of millet-derived compounds was conducted along with prediction of their ADMET profiles. Top five candidates were prioritized for Density Functional Theory (DFT) calculations and further analyses. Long-term molecular dynamics simulation (1 µs) were utilized to evaluate their binding, stability, and antagonizing abilities. Furthermore, reevaluation of their binding energy was conducted using the MM-PBSA method. This study reports millet-derived compounds, namely, Tricin 7-rutinoside, Tricin 7-glucoside, Glucotricin, Kaempferol, and Setarin. These compounds are predicted to be potent competitive inhibitors that can antagonize the interactions between bisphenols and ERRγ. These compounds could potentially assist in the development of future therapeutics. They may also be considered for use as food supplements, although further investigations, including wet-lab experiments and clinical studies, are needed.

Bisphenol H exposure disrupts Leydig cell function in adult rats via oxidative stress-mediated m6A modifications: Implications for reproductive toxicity

Bisphenol H (BPH) has emerged as a potential alternative to bisphenol A (BPA), which has been curtailed for use due to concerns over its reproductive and endocrine toxicity. This study investigates whether BPH exerts antiandrogenic effects by impairing Leydig cell function, a critical component in testosterone production. We administered orally BPH to adult male rats at doses of 0, 1, 10, and 100 mg/kg/day for 7 days. Notably, BPH treatment resulted in a dose-dependent reduction in testicular testosterone levels, with significant decreases observed at ≥ 1 mg/kg/day. Additionally, BPH affected the expression of key genes involved in steroidogenesis and cholesterol metabolism, including Nr5a1, Nr3c4, Lhcgr, Scarb1, and Star, at higher doses (10 and/or 100 mg/kg/day). The study also revealed alterations in antioxidant gene expression (Sod2 and Cat) and modulation of m6A-related genes (Ythdf1-3 and Foxo3) and their proteins. Through MeRIP-qPCR analysis, we identified increased m6A modifications in Scarb1 and Star genes following BPH exposure. In vitro experiments with primary Leydig cells confirmed that BPH enhanced oxidative stress and diminished testosterone production, which were partially mitigated by antioxidant vitamin E supplementation and Ythdf3 knockdown. Meanwhile, simultaneous administration of BPH and vitamin E to primary Leydig cells partially counteracted BPH-induced alterations in the Ythdf3 expression. Our findings underscore a novel mechanism by which BPH disrupts Leydig cell function through the oxidative stress-m6A modification-autophagy pathway, raising concerns about its potential reproductive toxicity.

Integrating detection and degradation of bisphenol A by photocatalytic fuel cell-driven photoelectrochemical sensor

To ensure food safety and environmental protection, it is crucial to rapidly identify and remove bisphenol A (BPA), a plasticizer commonly used in the inner lining of food containers and beverage packaging. Here, a photocatalytic fuel cell (PFC)-integrated self-powered photoelectrochemical (PEC) sensor is constructed. Unlike conventional single PEC or PFC sensors, this PFC-integrated PEC sensor relies on not only the difference in Fermi energy levels between photoanode and photocathode but also charge accumulation resulted from the oxidation of BPA by photogenerated holes. Consequently, this sensor achieved a remarkable maximum output power (Pmax) of 8.58 μW cm-2, as well as a high sensitivity, wide linear detection range (0.1-200 μM), low detection limit (0.05 μM), great stability, reproducibility, and real sample detection capability. This work integrates PFC and PEC technologies successfully for the rapid identification and efficient removal of BPA.

Indian and global scenarios of Bisphenol A distribution and its new analogues: Prevalence & probability exceedance

We compare, the prevalence, fate, and sources of Bisphenol A both globally and in India. India has the highest concentration of BPA and Bisphenol S(BPS) in general, with vegetables, particularly corn, beans, strings, and raw or canned vegetables, being the largest contributors. Among all the matrices, bisphenols (BPs) are found in the highest concentration in food, followed by surface water, wastewater, and indoor dust. BPA, BPS, and BPF are the most commonly reported analogues in India, with BPA being the most dominant category used worldwide. The highest concentration of BPs is observed in Uttar Pradesh, Punjab and Haryana that are three major agricultural states of India however, there is still a research gap regarding the dietary exposure to BPs on an individual level. Environmentally detected BPA occurs in a range of below detection to 10636 ng. L-1, with significant geographic variations. Interestingly, the order of abundance in India was maximum for BPS, which is contrary to the global average, where BPA is observed as most abundant. BPS is found to be the most common BPs analogue in surface water worldwide, with limited removal efficiency by both naturally remediation and conventional treatment methods. Similar patterns were observed in the US-India and Japan-Korea regions in terms of their source-sink-prevalence-fate dynamics. The probability of exceeding safe concentrations of BPs is higher in India and Korea, suggesting that these countries are more vulnerable to high prevalence concentrations and the subsequent public health hazards.

Emerging regulatory roles of noncoding RNAs induced by bisphenol a (BPA) and its alternatives in human diseases

Bisphenols (BPs), including BPA, BPF, BPS, and BPAF, are synthetic phenolic organic compounds and endocrine-disrupting chemicals. These organics have been broadly utilized to produce epoxy resins, polycarbonate plastics, and other products. Mounting evidence has shown that BPs, especially BPA, may enter into the human body and participate in the development of human diseases mediated by nuclear hormone receptors. Moreover, BPA may negatively affect human health at the epigenetic level through processes such as DNA methylation and histone acetylation. Recent studies have demonstrated that, as part of epigenetics, noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and small nucleolar RNAs (snoRNAs), have vital impacts on BP-related diseases, such as reproductive system diseases, nervous system diseases, digestive system diseases, endocrine system diseases, and other diseases. Moreover, based on the bioinformatic analysis, changes in ncRNAs may be relevant to normal activities and functions and BP-induced diseases. Thus, we conducted a meta-analysis to identify more promising ncRNAs as biomarkers and therapeutic targets for BP exposure and relevant human diseases. In this review, we summarize the regulatory functions of ncRNAs induced by BPs in human diseases and latent molecular mechanisms, as well as identify prospective biomarkers and therapeutic targets for BP exposure and upper diseases.

Beyond microbeads: Examining the role of cosmetics in microplastic pollution and spotlighting unanswered questions

The presence of microplastics in cosmetics and personal care products (C&PCPs) has been increasingly in the public eye since the early 2010s. Despite increasing research into the potential environmental and health effects of microplastics, most research to date on microplastics in C&PCPs has investigated "rinse-off" products, while the potential impacts of "leave-on" C&PCPs have been largely neglected, despite these products being purchased in greater volumes and often having two or more microplastic ingredients in their formulations(CosmeticsEurope, 2018b). This review aims to synthesize the current knowledge of microplastic in C&PCPs, assessing the potential environmental and human health impacts of C&PCPs and discussing the regulatory implications. The lack of studies on leave-on C&PCPs is significant, suggesting a severe knowledge gap regarding microplastic presence in, and emissions from, C&PCPs. There is a noticeable lack of studies on the (eco)toxicological consequences of microplastic exposure from C&PCPs. As a result, significant aspects of microplastic contamination may be overlooked in the microplastic legislations emerging globally (including from the European Commission), which intend to restrict microplastic use in C&PCPs but focus on rinse-off C&PCPs only. This review highlights the potential consequences of microplastics in leave-on C&PCPs for regulatory decision-making, particularly as alternatives to microplastics are considered during the phase-out periods and spotlights the need for sufficient monitoring and research on these alternatives, to avoid unforeseen consequences.

Exploring the relationships between exposure levels of bisphenols and phthalates and prostate cancer occurrence

We established an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneously analyzing the metabolites of bisphenols and phthalates in urine to identify the associations between these exposure levels and prostate cancer (PCa) based on a case-control study. After purifying urine samples with SPE, 18 metabolites were separated on a C18 column, and MS detection was performed. The UPLC-MS/MS method has been proven effective at evaluating bisphenol and phthalate exposure (0.020-0.20 μg/L of the limits of detection, 71.8 %∼119.4 % of recoveries, 0.4 %∼8.2 % of precision). Logistic regression explored the association between exposure level and PCa in 187 PCa cases and 151 controls. The detection rates of bisphenol A (BPA) and most phthalate metabolites were 100 % ranging from 0.06-46.74 and 0.12-899.92 μg/g creatinine, respectively, while the detection rates of other bisphenols and mono-benzyl phthalate (MBzP) are low, ranging from 0 % to 21.85 %. Correlation analysis of the metabolite levels indicated that the exposure sources of BPA, di-ethyl phthalate (DEP), and di(2-ethylhexyl) phthalate (DEHP) were different, and that the exposure sources of di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP) may differ between two groups. Logistic regression analysis revealed that BPA (OR<0.45 vs ≥1.43 =10.02) and DEHP exposure (OR<21.75 vs ≥45.42 =48.26) increased the risk of PCa.

Comparative in silico and in vitro evaluation of possible toxic effects of bisphenol derivatives in HepG2 cells

Introduction

Bisphenols are widely used in the production of polycarbonate plastics and resin coatings. Bisphenol A (BPA) is suggested to cause a wide range of unwanted effects and "low dose toxicity". With the search for alternative substances to BPA, the use of other bisphenol derivatives namely bisphenol F (BPF) and bisphenol S (BPS) has increased.

Methods

In the current study, we aimed to evaluate the in silico predicted inhibitory concentration 50s (pIC50s) of bisphenol derivatives on immune and apoptotic markers and DNA damage on HepG2 cells. Moreover, apoptotic, genotoxic and immunotoxic effects of BPA, BPF and BPS were determined comparatively. Effects of bisphenols on apoptosis were evaluated by detecting different caspase activities. The genotoxic effects of bisphenols were evaluated by measuring the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-oxoguanine glycosylase (OGG1). To determine the immunotoxic effect of bisphenol derivatives, the levels of interleukin 4 (IL-4) and interleukin 10 (IL-10), transforming growth factor beta (TGF-β) and tumor necrosis factor-alpha (TNF-α), which are known to be expressed by HepG2 cells, were measured. Results: In silico data indicate that all of the bisphenols may cause alterations in immune and apoptotic markers as well as DNA damage at low doses. İn vitro data revealed that all bisphenol derivatives could affect immune markers at inhibitory concentration 30s (IC30s). In addition, BPF and BPS may also have apoptotic immunotoxic effects.

Conclusion

Both in silico and in vivo research are needed further to examine the toxic effects of alternative bisphenol derivatives.

Anthropogenic stressors and the marine environment: From sources and impacts to solutions and mitigation

Human-released contaminants are often poorly understood wholistically in marine ecosystems. This review examines the sources, pathways, impacts on marine animals, and mitigation strategies of five pollutants (plastics, per- and polyfluoroalkyl substances, bisphenol compounds, ethynylestradiol, and petroleum hydrocarbons). Both abiotic and biotic mechanisms contribute to all five contaminants' movement. These pollutants cause short- and long-term effects on many biological processes genetically, molecularly, neurologically, physiologically, reproductively, and developmentally. We explore the extension of adverse outcome pathways to ecosystem effects by considering known inter-generational and trophic relations resulting in large-scale direct and indirect impacts. In doing so, we develop an understanding of their roles as environmental stressors in marine environments for targeted mitigation and future work. Ecosystems are interconnected and so international collaboration, standards, measures preceding mass production, and citizen involvement are required to protect and conserve marine life.

Occurrence of bisphenol analogues and their conjugated metabolites in foodstuff

Bisphenol analogues (BPs) are prevalent in diverse foodstuff samples worldwide. However, the occurrence of conjugated bisphenol A (BPA) and bisphenol S (BPS) metabolites in foodstuff remains poorly understood. This study analyzed eight BPs, and four conjugated BPA and BPS metabolites, in three animal-derived foodstuff and five plant-derived foodstuff samples from China. Results showed that fish foodstuff (9.7 ng/g ww) contained the highest mean concentration of BPA, followed by rice (5.1 ng/g ww) and beans foodstuff (3.6 ng/g ww). BPA-sulfate had higher mean concentrations than BPA-glucuronide in different foodstuff categories, except that in eggs foodstuff (p < 0.05). Compared with other foodstuff items, fish (3.4 ng/g ww) and vegetable (1.6 ng/g ww) foodstuff samples exhibited comparatively higher mean concentrations of BPS. Mean concentrations of BPS-sulfate were consistently higher than BPS-glucuronide in vegetables, meats, and fish foodstuff (p < 0.05). BPA contributed the major total dietary intake (DI) of BPs, with the mean DI of 435 ng/kg bw/day for women and 374 ng/kg bw/day for men, respectively. To our knowledge, this study is the first to investigate the occurrence of conjugated BPA and BPS metabolites in foodstuff, which enhances our comprehension of the origins of these conjugated metabolites in the human body.

Assessment of the impact of chemical pollution on endangered migratory fish in two major rivers of France, including spawning grounds

Water pollution is a one of the most contributors to aquatic biodiversity decline. Consequently, ecological risk assessment methods have been developed to investigate the effects of existing stresses on the environment, including the toxic effects of chemicals. One of the existing approaches to quantify toxic risks is called "Potentially Affected Fraction of species" (PAF), which estimates the potential loss of species within a group of species studied. In this study, the PAF method was applied to the Garonne catchment (southwest France) due to the limited information available on the involvement of water pollution in the decline of diadromous fish populations. This approach was used to quantify the potential toxic risk associated with chemical contamination of water for fish species. The objectives were to quantify this risk (1) in the Garonne and Dordogne rivers and (2) in the spawning grounds of two endangered anadromous fish species: the allis shad and the European sturgeon during the development period of their early life stages. Environmental pollution data was provided for 21 sites within the Garonne catchment between 2007 and 2022, and toxicity data was obtained specifically from freshwater toxicity tests on fish species. Then, for each site and each year, the potential toxic risk for a single substance (ssPAF) and for a mixture of substances (msPAF) was calculated and classified as high (>5 %), moderate (>1 % and < 5 %) or low (<1 %). Potential toxic risks were mostly moderate and mainly associated with: metals > other industrial pollutants and hygiene and care products > agrochemicals. In summary, this study highlights the probable involvement of water contamination on the decline, fate and restoration of diadromous fish populations in the Garonne catchment, focusing notably on the toxic effects on early life stages, a previously understudied topic.

An in vitro model system for testing chemical effects on microbiome-immune interactions - examples with BPX and PFAS mixtures

Introduction

More than 350,000 chemicals make up the chemical universe that surrounds us every day. The impact of this vast array of compounds on our health is still poorly understood. Manufacturers are required to carry out toxicological studies, for example on the reproductive or nervous systems, before putting a new substance on the market. However, toxicological safety does not exclude effects resulting from chronic exposure to low doses or effects on other potentially affected organ systems. This is the case for the microbiome-immune interaction, which is not yet included in any safety studies.

Methods

A high-throughput in vitro model was used to elucidate the potential effects of environmental chemicals and chemical mixtures on microbiome-immune interactions. Therefore, a simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species was cultured in vitro in a bioreactor that partially mimics intestinal conditions. The bacteria were continuously exposed to mixtures of representative and widely distributed environmental chemicals, i.e. bisphenols (BPX) and/or per- and polyfluoroalkyl substances (PFAS) at concentrations of 22 µM and 4 µM, respectively. Furthermore, changes in the immunostimulatory potential of exposed microbes were investigated using a co-culture system with human peripheral blood mononuclear cells (PBMCs).

Results

The exposure to BPX, PFAS or their mixture did not influence the community structure and the riboflavin production of SIHUMIx in vitro. However, it altered the potential of the consortium to stimulate human immune cells: in particular, activation of CD8+ MAIT cells was affected by the exposure to BPX- and PFAS mixtures-treated bacteria.

Discussion

The present study provides a model to investigate how environmental chemicals can indirectly affect immune cells via exposed microbes. It contributes to the much-needed knowledge on the effects of EDCs on an organ system that has been little explored in this context, especially from the perspective of cumulative exposure.

Health risks of Bisphenol-A exposure: From Wnt signaling perspective

Human beings are routinely exposed to chronic and low dose of Bisphenols (BPs) due to their widely pervasiveness in the environment. BPs hold similar chemical structures to 17β-estradiol (E2) and thyroid hormone, thus posing threats to human health by rendering the endocrine system dysfunctional. Among BPs, Bisphenol-A (BPA) is the best-known and extensively studied endocrine disrupting compound (EDC). BPA possesses multisystem toxicity, including reproductive toxicity, neurotoxicity, hepatoxicity and nephrotoxicity. Particularly, the central nervous system (CNS), especially the developing one, is vulnerable to BPA exposure. This review describes our current knowledge of BPA toxicity and the related molecular mechanisms, with an emphasis on the role of Wnt signaling in the related processes. We also discuss the role of oxidative stress, endocrine signaling and epigenetics in the regulation of Wnt signaling by BPA exposure. In summary, dysfunction of Wnt signaling plays a key role in BPA toxicity and thus can be a potential target to alleviate EDCs induced damage to organisms.

Exploring novel insights into the molecular mechanisms underlying Bisphenol A-induced toxicity: A persistent threat to human health

Bisphenol A (BPA) is a ubiquitous industrial chemical used in the production of polycarbonate plastics and epoxy resins, found in numerous consumer products. Despite its widespread use, its potential adverse health effects have raised significant concerns. This review explores the molecular mechanisms and evidence-based literature underlying BPA-induced toxicities and its implications for human health. BPA is an endocrine-disrupting chemical (EDC) which exhibits carcinogenic properties by influencing various receptors, such as ER, AhR, PPARs, LXRs, and RARs. It induces oxidative stress and contributes to cellular dysfunction, inflammation, and DNA damage, ultimately leading to various toxicities including but not limited to reproductive, cardiotoxicity, neurotoxicity, and endocrine toxicity. Moreover, BPA can modify DNA methylation patterns, histone modifications, and non-coding RNA expression, leading to epigenetic changes and contribute to carcinogenesis. Overall, understanding molecular mechanisms of BPA-induced toxicity is crucial for developing effective strategies and policies to mitigate its adverse effects on human health.

Exposure characteristics and cumulative risk assessment of bisphenol A and its substitutes: the Taiwan environmental survey for toxicants 2013

Introduction

Ever since the use of bisphenol A (BPA) has been restricted, concerns have been raised regarding the use of its substitutes, such as bisphenol S (BPS) and bisphenol F (BPF). Meanwhile, the EU European Food Safety Authority (EFSA) issued the new tolerable daily intake (TDI) after the latest re-risk assessment for BPA, which enforced the need for cumulative risk assessment in the population. This study was conducted to identify BPA and its substitute's exposure characteristics of the general Taiwanese population and estimate the cumulative risk of bisphenol exposure.

Methods

Urine samples (N = 366 [adult, 271; minor, 95]) were collected from individuals who participated in the Taiwan Environmental Survey for Toxicants 2013. The samples were analyzed for BPA, BPS, and BPF through ultraperformance liquid chromatography-tandem mass spectrometry. Daily intake (DI) levels were calculated for each bisphenol. Hazard quotients (HQs) were calculated with the consideration of tolerable DI and a reference dose. Additionally, hazard index (HI; sum of HQs for each bisphenol) values were calculated.

Results

Our study found that the median level of BPA was significantly higher in adults (9.63 μg/g creatinine) than in minors (6.63 μg/g creatinine) (p < 0.001). The DI of BPS was higher in female (0.69 ng/kg/day) than in male (0.49 ng/kg/day); however, the DIs of BPF and BPS were higher in boys (1.15 and 0.26 ng/kg/day, respectively) than in girls (0.57 and 0.20 ng/kg/day, respectively). Most HI values exceeded 1 (99% of the participants) after EFSA re-establish the TDI of BPA.

Discussion

Our study revealed that the exposure profiles and risk of BPA and its substitute in Taiwanese varied by age and sex. Additionally, the exposure risk of BPA was deemed unacceptable in Taiwan according to new EFSA regulations, and food contamination could be the possible source of exposure. We suggest that the risk of exposure to BPA and its substitutes in most human biomonitoring studies should be reassessed based on new scientific evidence.

Perinatal bisphenol S exposure exacerbates the oxidative burden and apoptosis in neonatal ovaries by suppressing the mTOR/autophagy axis

Bisphenol S (BPS) is an emerging environmental endocrine disruptor capable of crossing the placental barrier, resulting in widespread exposure to pregnant women due to its extensive usage. However, the impact of perinatal maternal exposure to BPS on reproductive health in offspring and the underlying molecular mechanism remain underexplored. In this study, gestational ICR mice were provided with drinking water containing 3.33 mg/L BPS to mimic possible human exposure in some countries. Results demonstrated that BPS accelerated the breakdown of germ-cell cysts and the assembly of primordial follicles in neonates, leading to oocyte over-loss. Furthermore, the expression levels of folliculogenesis-related genes (Kit, Nobox, Gdf9, Sohlh2, Kitl, Bmp15, Lhx8, Figla, and Tgfb1) decreased, thus compromising oocyte quality and disrupting early folliculogenesis dynamics. BPS also disrupted other aspects of offspring reproduction, including advancing puberty onset, disrupting the estrus cycle, and impairing fertility. Further investigation found that BPS exposure inhibited the activities and expression levels of antioxidant-related enzymes in neonatal ovaries, leading to the substantial accumulation of MDA and ROS. The increased oxidative burden exacerbated the intracellular apoptotic signaling, manifested by increased expression levels of pro-apoptotic markers (Bax, Caspase 3, and Caspase 9) and decreased expression levels of anti-apoptotic marker (Bcl2). Concurrently, BPS inhibited autophagy by increasing p-mTOR/mTOR and decreasing p-ULK1/ULK1, subsequently down-regulating autophagy flux-related biomarkers (LC3b/LC3a and Beclin-1) and impeding the degradation of autophagy substrate p62. However, the imbalanced crosstalk between autophagy, apoptosis and oxidative stress homeostasis was restored after rapamycin treatment. Collectively, the findings demonstrated that BPS exposure induced reproductive disorders in offspring by perturbing the mTOR/autophagy axis, and such autophagic dysfunction exacerbated redox imbalance and promoted excessive apoptosis. These results provide novel mechanistic insights into the role of autophagy in mitigating BPS-induced intergenerational reproductive dysfunction.

Disposables used cumulatively in routine IVF procedures could display toxicity

STUDY QUESTION

Is there a cumulative toxicity of disposables used in IVF procedures?

SUMMARY ANSWER

A toxicity may be detected when consumables are used cumulatively, while no toxicity is detected when the same consumables are used and tested individually.

WHAT IS KNOWN ALREADY

Many components of items used in IVF laboratories may impair human embryonic development. Consequently, it is necessary to screen all reagents and materials which could be in contact with gametes and embryos. Toxicity tests, such as the mouse embryo assay and the human sperm motility assay (HSMA), are used by manufacturers as quality control tools to demonstrate the safety of their products. This evaluation is currently individually performed for each single consumable. However, during an IVF cycle, several devices are used sequentially, potentially creating a cumulative exposure to chemical contaminants, which could not be detected for individually tested consumables.

STUDY DESIGN, SIZE, DURATION

The objective of this observational study conducted from March 2021 to October 2022 was to evaluate with the HSMA methodology if there was a cumulative toxicity when several disposables are sequentially used. Fourteen categories of consumables currently used in routine IVF procedures were studied, which included devices used for sperm and oocyte collection (cups, condoms, and oocyte aspiration needles), manipulation (flasks, tubes, tips, pipettes, embryo transfer catheters, syringes, and gloves), culture (dishes), and storage (straws).

PARTICIPANTS/MATERIALS, SETTING, METHODS

After obtaining patient consent, the surplus semen assessed as having normal parameters according to the World Health Organization 2010 criteria were used to perform the HSMAs. First, each consumable was tested individually. Then, associations of three, four, and five consumables, previously validated as non-toxic when tested individually, were analyzed. HSMAs were conducted three times to ensure reproducibility, with a defined toxicity threshold of a sperm motility index (SMI) below 0.85 in at least two of three tests.

MAIN RESULTS AND THE ROLE OF CHANCE

Thirty-six references of disposables were first individually tested across 53 lots. Forty-nine (92%) demonstrated compliance. However, four (8%) devices revealed toxicity: one lot of 1 ml syringes, two lots of sperm cups, and one lot of 25 cm2 flasks. These four references were excluded from the IVF routine procedures. A total of 48 combinations of consumables were assessed, involving 41 lots from 32 references that were previously individually tested. Among the evaluated combinations, 17 out of 48 (35%) associations exhibited toxicity with a SMI below 0.85 for two of the three tests (n = 8) or all the three tests (n = 9). Notably, three out of 17 (18%) of the three-consumable associations, five out of 16 (31%) of the four-consumable associations, and nine out of 15 (60%) of the five-consumable associations were found not compliant. The toxicity did not originate from a single consumable, because only consumables that were individually pre-validated as non-toxic were included in the combinations, but the toxicity had a cumulative origin. The risk of cumulative toxicity increased with the number of consumables included in the association (Cochran-Mantel-Haenszel statistic, P = 0.013).

LIMITATIONS, REASONS FOR CAUTION

The high proportion of non-compliant combinations of disposables can be attributed directly to the extreme rigorous extraction conditions employed during the tests, which could deviate from the conditions encountered in routine clinical use. Also, the methodology employed in the HSMAs (e.g. toxicity extraction duration, sperm concentrations, and protein supplementation of the medium) can influence the sensitivity of the tests.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the significance of performing toxicity testing on devices before introducing them into clinical practice. Disposables should be tested individually to detect immediate toxicities and also in combination. Our results advocate rationalizing the number of consumables used in each IVF procedure and re-evaluating the use of glass consumables.

STUDY FUNDING/COMPETING INTEREST(S)

This study received fundings from GCS Ramsay Santé pour l'Enseignement et la Recherche (Paris, France) and the Centre de Biologie Médicale BIOGROUP (Le Chesnay-Rocquencourt, France). The authors declare that they have no conflict of interest that could be perceived as prejudicing the impartiality of the reported research.

TRIAL REGISTRATION NUMBER

N/A.

Target and Suspect Screening for Organic Additives in Six Classifications of Personal Care Products Using Liquid Chromatography-High-Resolution Mass Spectrometry

Personal care products (PCPs) are integral components of daily human existence, including a large number of chemicals intentionally added for functional attributes (e.g., preservatives and fragrances) or unintentionally present, such as plasticizers. This investigation aimed to optimize the methodology for target and suspect screening via liquid chromatography-high-resolution mass spectrometry, focusing on nine prevalent organic additives (comprising bisphenols A, F, and S, methyl, ethyl, propyl, and butylparaben, 5-chloro-2-methyl-4-isothiazolin-3-one, and 4-hydroxybenzoic acid). A total of 50 high-selling PCPs were purchased from the local online market as samples. In detail, PCP samples were classified into body washes, shampoos, hair conditioners, facial cleansers, body lotions, and moisture creams. For calibration, the quality assurance and quality control results demonstrated a coefficient of determination (R2) surpassing 0.999, with detection and quantification limits ranging from 2.5 to 100.0 ng/g. For recovery experiments, replicate recoveries (n = 5) ranged from 61 to 134%. In purchased PCP samples, five of the nine target compounds were detected via a target screening. Methylparaben exhibited the highest concentration (7860 mg/kg) in a facial cleanser, which is known as an endocrine-disrupting chemical. A total of 248 suspects of organic additives were screened in PCPs, leading to a tentative identification of 9. Confirmation (confidence level 1) via reference standards was achieved for three suspects, while six were tentatively identified with a confidence level of 2. This two-step extraction methodology utilizing methyl tert-butyl ether and isopropyl alcohol enabled simultaneous analysis of diverse chemical groups with distinct properties.

Plastic compounds and liver diseases: Whether bisphenol A is the only culprit

Plastics, while providing modern conveniences, have become an inescapable source of global concern due to their role in environmental pollution. Particularly, the focus on bisphenol A (BPA) reveals its biohazardous nature and association with liver issues, specifically steatosis. However, research indicates that BPA is just one facet of the problem, as other bisphenol analogues, microplastics, nanoplastics and additional plastic derivatives also pose potential risks. Notably, BPA is implicated in every stage of non-alcoholic fatty liver disease (NAFLD) onset and progression, surpassing hepatitis B virus as a primary cause of chronic liver disease worldwide. As plastic contamination tops the environmental contaminants list, urgent action is needed to assess causative factors and mitigate their impact. This review delves into the molecular disruptions linking plastic pollutant exposure to liver diseases, emphasizing the broader connection between plastics and the rising prevalence of NAFLD.

Occurrence, source apportionment and ecological risk of bisphenol analogues in river sediments in areas with different land use patterns

Bisphenol analogues (BPs) have gained increasing attention in recent years due to their ubiquitousness and potential endocrine disrupting properties in environments. However, little information is available on their spatiotemporal distribution, source apportionment and ecological risk in river sediments, especially the case in river basins with a high population density and those typical regions with agricultural-urban gradient, where land use patterns and intensity of human activity are varying. In this study, field investigations of BPs in the sediment of the entire Qinhuai River Basin, a typical agricultural-suburban agricultural-urban gradient area, were conducted before and after the flood period. Thirty-two sites were sampled for six types of BPs, resulted in no significant difference in the concentration of ΣBPs between the two periods, with ΣBPs ranging from 3.92 to 151 ng/g and 2.16-59.0 ng/g, respectively. Bisphenol A (BPA) was the main contributor. Whereas a multivariate analysis of variance (MANOVA) suggested that the composition structure of BPs had been influenced by water periods. The land use patterns had an impact on the distribution of ΣBPs in river sediments, which was more significant in after the flood period, with ΣBPs in urban rivers was 1.85 times, 3.44 times, and 3.08 times higher than the suburban rivers, agricultural rivers, and reservoirs, respectively. Yet land use types did not significantly alter the composition structure of BPs. The correlation analysis between BPs and the physicochemical properties of sediments showed a significant positive correlation between BPA and total organic carbon (TOC). The positive matrix factorization model (PMF) suggested that BPs in sediments of the basin might be influenced by industrial coatings, textiles, electronics and biopharmaceuticals, as well as urban wastewater or solid waste generated from daily life. The ecological risk assessment posed by BPA, based on the risk quotient, indicated that the ecological risk of BPA in sediments was low for three indicator benthic organisms: crustaceans, worms, and mollusks. However, the risk of BPA in river sediments varied among different land use patterns, with the risk ranking as follows: reservoirs < agricultural rivers < suburban rivers < urban rivers.

Bisphenol A promotes cell death in healthy respiratory system cells through inhibition of cell proliferation and induction of G2/M cell cycle arrest

Bisphenol A (BPA) is a substance that can harm the environment and human health by interfering with the normal functioning of the body's hormonal system. It is commonly found in various plastic-based products such as cosmetics, canned foods, beverage containers, and medical equipment and as well as it can also be absorbed by inhalation. There have been limited studies on the effects of BPA on lung fibroblasts, and it is still unclear how high levels of BPA can impact respiratory system cells, particularly the lungs and trachea. In this research, we aimed to investigate the cell cycle disruption potential of BPA on respiratory system cells by examining healthy trachea and lung cells together for the first time. The findings indicated that BPA exposure can alter the healthy cells' morphology, leading to reduced cellular viability that has been assessed by MTT and SRB assays. BPA treatment was able to activate caspase3 as expected, which could cause apoptosis in treated cells. Although the highest dose of BPA did not increase the apoptotic rate of rat trachea cells, it remarkably caused them to become necrotic (52.12%). In addition to quantifying the induction of apoptosis and necrosis by BPA, cell cycle profiles were also determined using flow cytometry. Thereby, BPA treatment unexpectedly inhibited the cell cycle's progression by causing G2/M cell cycle arrest in both lung and tracheal cells, which hindered cell proliferation. The findings of the study suggested that exposure to BPA could lead to serious respiratory problems, even respiratory tract cancers via alterations in the cell cycle.

Toxicity of low dose bisphenols in human iPSC-derived cardiomyocytes and human cardiac organoids - Impact on contractile function and hypertrophy

Bisphenol A (BPA) and its analogs are common environmental chemicals with various adverse health impacts, including cardiac toxicity. In this study, we examined the long term effect of low dose BPA and three common BPA analogs, bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF), in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) based models. HiPSC-CMs and human cardiac organoids were exposed to these chemicals for 4-5 or 20 days. 1 nM BPA, BPS, and BPAF, but not BPF, resulted in suppressed myocyte contractility, retarded contraction kinetics, and aberrant Ca2+ transients in hiPSC-CMs. In cardiac organoids, BPAF and BPA, but not the other bisphenols, resulted in suppressed contraction and Ca2+ transients, and aberrant contraction kinetics. The order of toxicities was BPAF > BPA>∼BPS > BPF and the toxicities of BPAF and BPA were more pronounced under longer exposure. The impact of BPAF on myocyte contraction and Ca2+ handling was mediated by reduction of sarcoplasmic reticulum Ca2+ load and inhibition of L-type Ca2+ channel involving alternation of Ca2+ handling proteins. Impaired myocyte Ca2+ handling plays a key role in cardiac pathophysiology and is a characteristic of cardiac hypertrophy; therefore we examined the potential pro-hypertrophic cardiotoxicity of these bisphenols. Four to five day exposure to BPAF did not cause hypertrophy in normal hiPSC-CMs, but significantly exacerbated the hypertrophic phenotype in myocytes with existing hypertrophy induced by endothelin-1, characterized by increased cell size and elevated expression of the hypertrophic marker proBNP. This pro-hypertrophic cardiotoxicity was also occurred in cardiac organoids, with BPAF having the strongest toxicity, followed by BPA. Our findings demonstrate that long term exposures to BPA and some of its analogs cause contractile dysfunction and abnormal Ca2+ handling, and have potential pro-hypertrophic cardiotoxicity in human heart cells/tissues, and suggest that some bisphenol chemicals may be a risk factor for cardiac hypertrophy in human hearts.

Rats' testicular toxicity induced by bisphenol A is lessened by crocin via an antiapoptotic mechanism and bumped P-glycoprotein expression

Bisphenol A (BPA) engenders testicular toxicity via hydroxyl free radical genesis in rat striatum and depletion of the endogenous antioxidants in the epididymal sperms. The multi-drug resistance efflux carrier; P-glycoprotein (P-gp) expel the BPA from the testis and is responsible for the testicular protection through the deactivation of numerous xenobiotics. In our study, we investigated whether the BPA-induced testicular toxicity could be circumvented through administration of an antioxidant; crocin (Cr). Implication of P-gp expression was also investigated. Rats administered BPA (10 mg/kg b.w. orally for 14 days), dropped the body weight, testes/body weight ratio, total protein content, testosterone, follicle stimulating hormone, luteinizing hormone, and sperm motility & count, total antioxidant status, glutathione content and antioxidant enzymes (superoxide dismutase and catalase), concomitant with the elevation of the percentage abnormal sperm morphology, as well as testicular lipid peroxides and nitrite/nitrate levels. Histopathological examination showed spermatogenesis disorders after the BPA rats exposure. The immunohistochemical study showed up-regulation of the P-gp as evident by increasing immunoreactivity in interstitial cells, with positive localization in some spermatogonia cells. The BPA-treated rats showed positive immunoreactivity against caspase-3. The co-intake of Cr (200 mg/kg b.w./day, i.p. 14 days) along with the BPA, significantly ameliorated all the mentioned parameters, boosted histopathological image, fell the caspase-3 up-regulation, and perched the P-gp expression. We showed that, Cr promotes P-gp as an approach to nurture the testicles against the BPA toxicity. In conclusion; Cr lessens the oxidative stress conditions to safeguard rats from the BPA-induced testicular toxicity and sex hormones abnormalities, reducing apoptosis and up-regulating P-gp.

Molecular insights into the antioxidative and anti-inflammatory effects of P-coumaric acid against bisphenol A-induced testicular injury: In vivo and in silico studies

This study investigated the protective effects of p-coumaric acid (PCA) against bisphenol A (BPA)-induced testicular toxicity in male rats. The rats were divided into control, BPA, BPA+PCA50, BPA+PCA100, and PCA100 groups. Following a 14-day treatment period, various analyses were conducted on epididymal sperm quality and testicular tissues. PCA exhibited dose-dependent cytoprotective, antioxidant, and anti-inflammatory effects, ameliorating the decline in sperm quality induced by BPA. The treatment elevated antioxidant enzyme activities (SOD, GPx, CAT) and restored redox homeostasis by increasing cellular glutathione (GSH) and reducing malondialdehyde (MDA) levels. PCA also mitigated BPA-induced proinflammatory responses while reinstating anti-inflammatory IL-10 levels. Apoptotic parameters (p53 and p38-MAPK) were normalized by PCA in BPA-treated testicular tissue. Immunohistochemical and immunofluorescent analyses confirmed the cytoprotective and anti-inflammatory effects of PCA, evidenced by the upregulation of HO-1, Bcl-2, and Nrf-2 and the downregulation of the proapoptotic gene Bax in BPA-induced testicular intoxication. PCA corrected the disturbance in male reproductive hormone levels and reinstated testosterone biosynthetic capacity after BPA-induced testicular insult. In silico analyses suggested PCA's potential modulation of the oxidative stress KEAP1/NRF2/ARE pathway, affirming BPA's inhibitory impact on P450scc. This study elucidates BPA's molecular disruption of testosterone biosynthesis and highlights PCA's therapeutic potential in mitigating BPA's adverse effects on testicular function, showcasing its cytoprotective, anti-inflammatory, and hormone-regulating properties. The integrated in vivo and in silico approach offers a comprehensive understanding of complex mechanisms, paving the way for future research in reproductive health and toxicology, and underscores the importance of employing BPA-free plastic wares in semen handling.

Structural insight into the mechanisms and interacting features of endocrine disruptor Bisphenol A and its analogs with human estrogen-related receptor gamma

Bisphenol A (BPA) is a very important chemical from the commercial perspective. Many useful products are made from it, so its production is increasing day by day. It is widely known that Bisphenol A (BPA) and its analogs are present in the environment and that they enter our body through various routes on a daily basis as we use things made of this chemical in our daily lives. BPA has already been reported to be an endocrine disruptor. Studies have shown that BPA binds strongly to the human estrogen-related receptor gamma (ERRγ) and is an important target of it. This study seeks to understand how it interacts with ERRγ. Molecular docking of BPA and its analogs with ERRγ was performed, and estradiol was taken as a reference. Then, physico-chemical and toxicological analysis of BPA compounds was performed. Subsequently, the dynamic behavior of ERRγ and ERRγ-BPA compound complexes was studied by molecular dynamics simulations over 500 ns, and using this simulated data, their binding energies were again calculated using the MM-PBSA method. We observed that the binding affinity of BPA and its analogs was much higher than that of estradiol, and apart from being toxic, they can be easily absorbed in our body as their physicochemical properties are similar to those of oral medicines. Therefore, this study facilitates the understanding of the structure-activity relationship of ERRγ and BPA compounds and provides information about the key amino acid residues of ERRγ that interact with BPA compounds, which can be helpful to design competitive inhibitors so that we can interrupt the interaction of BPA with ERRγ. In addition, it provides information on BPA and its analogs and will also be helpful in developing new therapeutics.

Potential application of 2D nano-layered MXene in analysing and remediating endocrine disruptor compounds and heavy metals in water

With the advancement of technologies and growth of the economy, it is inevitable that more complex processes are deployed, producing more heterogeneous wastewater that comes from biomedical, biochemical and various biotechnological industries. While the conventional way of wastewater treatment could effectively reduce the chemical oxygen demand, pH and turbidity of wastewater, trace pollutants, specifically the endocrine disruptor compounds (EDCs) that exist in µg L-1 or ng L-1 have further hardened the detection and removal of these biochemical pollutants. Even in small amounts, EDC could interfere human's hormone, causing severe implications on human body. Hence, this review elucidates the recent insights regarding the effectiveness of an advanced 2D material based on titanium carbide (Ti3C2Tx), also known as MXene, in detecting and removing EDCs. MXene's highly tunable feature also allows its surface chemistry to be adjusted by adding chemicals with different functional groups to adsorb different kinds of EDCs for biochemical pollution mitigation. At the same time, the incorporation of MXene into sample matrices also further eases the analysis of trace pollutants down to ng L-1 levels, thereby making way for a more cleaner and comprehensive wastewater treatment. In that sense, this review also highlights the progress in synthesizing MXene from the conventional method to the more modern approaches, together with their respective key parameters. To further understand and attest to the efficacy of MXene, the limitations and current gaps of this potential agent are also accentuated, targeting to seek resolutions for a more sustainable application.

Enhanced inhibition of human and rat aromatase activity by benzene ring substitutions in bisphenol A: QSAR structure-activity relationship and in silico docking analysis

Bisphenol A (BPA) is a widely used plastic material, but its potential endocrine disrupting effect has restricted its use. The BPA alternatives have raised concerns. This study aimed to compare inhibitory potencies of 11 BPA analogues on human and rat placental aromatase (CYP19A1). The inhibitory potency on human CYP19A1 ranged from bisphenol H (IC50, 0.93 μM) to tetramethyl BPA and tetrabromobisphenol S (ineffective at 100 μM) when compared to BPA (IC50, 73.48 μM). Most of them were mixed/competitive inhibitors and inhibited estradiol production in human BeWo cells. Molecular docking analysis showed all BPA analogues bind to steroid active site or in between steroid and heme of CYP19A1 and form a hydrogen bond with catalytic residue Met374. Pharmacophore analysis showed that there were 4 hydrophobic regions for BPA analogues, with bisphenol H occupying 4 regions. Bivariate correlation analysis showed that LogP (lipophilicity) and LogS (water solubility) of BPA analogues were correlated with their IC50 values. Computerized drug metabolism and pharmacokinetics analysis showed that bisphenol H, tetrabromobisphenol A, and tetrachlorobisphenol A had low solubility, which might explain their weaker inhibition on estradiol production on BeWo cells. In conclusion, BPA analogues mostly can inhibit CYP19A1 and the lipophilicity determines their inhibitory strength.