Bisphenol A and its analogs induce morphological and biochemical alterations in human peripheral blood mononuclear cells (in vitro study)

Occurrence and health risks of multiple emerging bisphenol S analogues in pregnant women from South China

Recently, there has been increasing concern regarding the emergence of bisphenol S analogues (BPSs) due to their potential toxicity. However, their exposure levels and associated health risks in susceptible populations remain unknown. In our study, we analyzed bisphenol A (BPA), along with 11 common BPA analogues (BPAs), and nine emerging BPSs in urine samples collected from 381 pregnant women in South China. All nine BPSs were first detected in pregnant women's urine. In addition to BPA, two BPAs, three BPSs including Diphenylsulfone (DPS), Bis(phenylsulfonyl)phenol (DBSP) and Bis(3-allyl-4-hydroxyphenyl)sulfone (TGSA), were identified as the predominant bisphenols, with detection frequencies ranging from 53-100 %. BPA still exhibited the highest median concentration at 0.624 ng/mL, followed by DPS (0.169 ng/mL), BPS (0.063 ng/mL) and DBSP (0.023 ng/mL). Importantly, mothers with higher levels of BPA, DBSP, DPS, and TGSA in their urine are statistically more likely to give birth to premature infants with shorter lengths at birth or smaller head circumference (p < 0.05). Although the median exposure to 21 bisphenols did not exceed the tolerable daily intake (TDI) of BPA, it did surpass the recently proposed BPA TDI (0.2 ng/kg bw/day) by a factor ranging from 1.1-99 times. This study signifies the first report unveiling the prevalence of multiple bisphenols, particularly emerging BPSs, in the urine of pregnant women in South China.

Bisphenol A and bisphenol AF co-exposure induced apoptosis of human ovarian granulosa cells via mitochondrial dysfunction

Bisphenol A (BPA) is a synthetic chemical primarily utilized in the manufacturing of polycarbonate plastics and epoxy resins that are present in various consumer products. While the BPA impacts on female reproductive toxicity have been widely investigated, very little is currently identified about the mixed toxicity of BPA and bisphenol AF (BPAF), another common BPA derivative that is used in many industrial applications. In this study, we assessed the effect of co-exposure of BPA (30 and 50 μM) and BPAF (3 and 5 μM) on mitochondrial dysfunction in human granulosa cells (KGN cells) for 24 h. Our results exhibited that high-concentration bisphenol individual or their mixture exposure of KGN cells induced significant mitochondrial dysfunction by reducing mitochondrial mass, reducing ATP production, and damaging the mitochondrial respiratory chain. In addition, we found that the combination of BPA and BPAF significantly induced mitochondrial stress by increasing calcium levels and the production of ROS in mitochondria. Mitochondrial stress induced by BPA and BPAF was determined to be a mechanism that promoted cell apoptosis after pretreating the cells with the mitochondrial-targeted antioxidant and the calcium chelator. Our results provide novel evidence of the cytotoxicity of mixtures of different bisphenol compounds.

Low-dose bisphenols exposure sex-specifically induces neurodevelopmental toxicity in juvenile rats and the antagonism of EGCG

Bisphenols (BPs) can negatively affect neurobehaviors in rats, whereas the mechanism remains unclear. Here, the mechanism of BPs-induced neurodevelopmental toxicity and its effective detoxification measures were investigated in vitro and in vivo. In in vitro experiments, primary hippocampal neurons from neonatal rats of different genders were treated with bisphenol A (BPA), bisphenol S (BPS) and bisphenol B (BPB) at 1 nM-100 μM, epigallocatechin gallate (EGCG) and G15, an antagonist of G protein-coupled estrogen receptor (GPER) for 7 d. Results indicated that BPs affected neuronal morphogenesis, impaired GABA synthesis and Glu/GABA homeostasis. Neuronal morphogenetic damage induced by low-doses BPA may be mediated by GPER. Neurotoxicity of BPS is weaker than BPA and BPB. In in vivo studies, exposure to BPA (0.5 μg/kg·bw/day) on PND 10-40 caused oxidative stress and inflammation in rat hippocampus, disrupted neuronal morphogenesis and neurotransmitter homeostasis, ultimately impaired spatial memory of rats. Males are more sensitive to BPA exposure than females. Both in vivo and in vitro studies indicated that EGCG, a phytoestrogen, can alleviate BPA-induced neurotoxicity. Taken together, low-doses BPA exposure sex-specifically disrupted neurodevelopment and further impaired learning and memory ability in rats, which may be mediated by GPER. Promisingly, EGCG effectively mitigated the BPA-induced neurodevelopmental toxicity.

A review on immunomodulatory effects of BPA analogues

Bisphenol A (BPA) is a known endocrine disruptor found in many consumer products that humans come into contact with on a daily basis. Due to increasing concerns about the safety of BPA and the introduction of new legislation restricting its use, industry has responded by adopting new, less studied BPA analogues that have similar polymer-forming properties. Some BPA analogues have already been shown to exhibit effects similar to BPA, for example, contributing to endocrine disruption through agonistic or antagonistic behaviour at various nuclear receptors such as estrogen (ER), androgen (AR), glucocorticoid (GR), aryl hydrocarbon (AhR), and pregnane X receptor (PXR). Since the European Food Safety Authority (EFSA) issued a draft re-evaluation of BPA and drastically reduced the temporary tolerable daily intake (t-TDI) of BPA from 4 mg/kg body weight/day to 0.2 ng/kg body weight/day due to increasing concern about the toxic properties of BPA, including its potential to disrupt immune system processes, we conducted a comprehensive review of the immunomodulatory activity of environmentally abundant BPA analogues. The results of the review suggest that BPA analogues may affect both the innate and acquired immune systems and can contribute to various immune-mediated conditions such as hypersensitivity reactions, allergies, and disruption of the human microbiome.

Genetic background in the rat affects endocrine and metabolic outcomes of bisphenol F exposure

Environmental bisphenol compounds like bisphenol F (BPF) are endocrine-disrupting chemicals (EDCs) affecting adipose and classical endocrine systems. Genetic factors that influence EDC exposure outcomes are poorly understood and are unaccounted variables that may contribute to the large range of reported outcomes in the human population. We previously demonstrated that BPF exposure increased body growth and adiposity in male N/NIH heterogeneous stock (HS) rats, a genetically heterogeneous outbred population. We hypothesize that the founder strains of the HS rat exhibit EDC effects that were strain- and sex-dependent. Weanling littermate pairs of male and female ACI, BN, BUF, F344, M520, and WKY rats randomly received either vehicle (0.1% EtOH) or 1.125 mg BPF/l in 0.1% EtOH for 10 weeks in drinking water. Body weight and fluid intake were measured weekly, metabolic parameters were assessed, and blood and tissues were collected. BPF increased thyroid weight in ACI males, thymus and kidney weight in BUF females, adrenal weight in WKY males, and possibly increased pituitary weight in BN males. BUF females also developed a disruption in activity and metabolic rate with BPF exposure. These sex- and strain-specific exposure outcomes illustrate that HS rat founders possess diverse bisphenol-exposure risk alleles and suggest that BPF exposure may intensify inherent organ system dysfunction existing in the HS rat founders. We propose that the HS rat will be an invaluable model for dissecting gene EDC interactions on health.

Comparative study of the effect of oleuropein and hydroxytyrosol rich extracts on the reproductive toxicity induced by bisphenol A in male rats: biochemical, histopathological, and molecular analyses

Bisphenol A, or BPA, goes into the composition of a large number of products including sunglasses, infant's feeding bottles, receipts, or food packaging. Nowadays, there is a growing evidence that BPA may be at the origin of several physiological malignancies. Oleuropein and hydroxytyrosol extracted from olive leaves are highly investigated for numerous health benefits. The present work investigates the potential protective proprieties of olive leaf extracts against BPA-induced testicular damage in Wistar rats. Thirty-two animals were randomly divided into 4 groups: control, BPA-treated (10 mg/kg), BPA and oleuropein rich extract (16 mg/kg) treatment, and the last group treated with BPA and hydroxytyrosol rich extract (16 mg/kg). Biochemical parameters and histological and molecular analyses were evaluated. Our data demonstrated that BPA treatment caused significant alteration in biochemical parameters, disorganization of germinal epithelium, an up-regulation of p53 and Bax, and a reduction of Bcl-2 protein levels. The ingestion of oleuropein- and hydroxytyrosol-rich extracts attenuated BPA-induced biochemical and histological changes. In fact, olive leaf extracts enhanced the enzymatic antioxidant system and the level of Bcl-2, and reduced the expression of p53 and Bax. Fairly, our findings propose that olive leaf extracts may compete with BPA-induced reprotoxicity in vivo.

Effects of endocrine disrupting compounds on female fertility

Endocrine Disrupting Compounds or Chemicals (EDCs) constitute an extensive and varied group of mostly non-natural chemicals that have the ability to imitate any aspect of hormone action, perturbing many physiological functions in humans and animals. As for female fertility, several EDCs are associated with adverse effects in the regulation of steroidogenesis, higher miscarriage rates as well as lower fertilization and embryo implantation rates and some of them are considered to decrease the number of high-quality embryos in assisted reproductive technology (ART) pregnancy. The most common EDCs are pesticides, hexachlorobenzene (HCB), hexachlorocyclohexane (HCH) and especially phthalates and bisphenols which are used in thousands of products as plasticizers. Among all, Bisphenol A (BPA) is one of the most permeating and well-studied EDCs. BPA's action resembles that of estradiol affecting negatively the female reproductive system in various ways. This review summarizes the most recent literature on the impact of EDCs in female fertility.

Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs

In 2015, EFSA established a temporary tolerable daily intake (t-TDI) for BPA of 4 μg/kg body weight (bw) per day. In 2016, the European Commission mandated EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation. The CEP Panel concluded that it is Unlikely to Very Unlikely that BPA presents a genotoxic hazard through a direct mechanism. Taking into consideration the evidence from animal data and support from human observational studies, the immune system was identified as most sensitive to BPA exposure. An effect on Th17 cells in mice was identified as the critical effect; these cells are pivotal in cellular immune mechanisms and involved in the development of inflammatory conditions, including autoimmunity and lung inflammation. A reference point (RP) of 8.2 ng/kg bw per day, expressed as human equivalent dose, was identified for the critical effect. Uncertainty analysis assessed a probability of 57-73% that the lowest estimated Benchmark Dose (BMD) for other health effects was below the RP based on Th17 cells. In view of this, the CEP Panel judged that an additional uncertainty factor (UF) of 2 was needed for establishing the TDI. Applying an overall UF of 50 to the RP, a TDI of 0.2 ng BPA/kg bw per day was established. Comparison of this TDI with the dietary exposure estimates from the 2015 EFSA opinion showed that both the mean and the 95th percentile dietary exposures in all age groups exceeded the TDI by two to three orders of magnitude. Even considering the uncertainty in the exposure assessment, the exceedance being so large, the CEP Panel concluded that there is a health concern from dietary BPA exposure.

Combined Toxic Effects of BPA and Its Two Analogues BPAP and BPC in a 3D HepG2 Cell Model

Bisphenol A (BPA) is one of the most commonly used substances in the manufacture of various everyday products. Growing concerns about its hazardous properties, including endocrine disruption and genotoxicity, have led to its gradual replacement by presumably safer analogues in manufacturing plastics. The widespread use of BPA and, more recently, its analogues has increased their residues in the environment. However, our knowledge of their toxicological profiles is limited and their combined effects are unknown. In the present study, we investigated the toxic effects caused by single bisphenols and by the combined exposure of BPA and its two analogues, BPAP and BPC, after short (24-h) and prolonged (96-h) exposure in HepG2 spheroids. The results showed that BPA did not reduce cell viability in HepG2 spheroids after 24-h exposure. In contrast, BPAP and BPC affected cell viability in HepG2 spheroids. Both binary mixtures (BPA/BPAP and BPA/BPC) decreased cell viability in a dose-dependent manner, but the significant difference was only observed for the combination of BPA/BPC (both at 40 µM). After 96-h exposure, none of the BPs studied affected cell viability in HepG2 spheroids. Only the combination of BPA/BPAP decreased cell viability in a dose-dependent manner that was significant for the combination of 4 µM BPA and 4 µM BPAP. None of the BPs and their binary mixtures studied affected the surface area and growth of spheroids as measured by planimetry. In addition, all BPs and their binary mixtures studied triggered oxidative stress, as measured by the production of reactive oxygen species and malondialdehyde, at both exposure times. Overall, the results suggest that it is important to study the effects of BPs as single compounds. It is even more important to study the effects of combined exposures, as the combined effects may differ from those induced by single compounds.

Comparative evaluation of the effects of bisphenol derivatives on oxidative stress parameters in HepG2 cells

Bisphenol A (BPA) BPA is an endocrine-disrupting chemical that has a wide range of uses. Exposure to BPA can be by oral, inhalation, and parenteral routes. Although its use in several products is limited, there is still concern on its adverse health effects, particularly for susceptible populations like children. Alternative bisphenols, such as bisphenol S (BPS) and bisphenol F (BPF), are now being used instead of BPA, although there is little information on the toxicity of these bisphenols. BPF is used as a plasticizer in the production of several industrial materials as well as in the coating of drinks and food cans. BPS is used in curing fast-drying epoxy glues, as a corrosion inhibitor and as a reactant in polymer reactions. In this study, the possible toxic effects of BPA, BPS, and BPF in HepG2 cells were evaluated comparatively. For this purpose, their effects on cytotoxicity, production of intracellular reactive oxygen species (ROS), oxidant/antioxidant parameters, and DNA damage have been examined. The cytotoxicity potentials of different bisphenols were found to be as BPS > BPF > BPA. All bisphenol derivatives caused increases in intracellular ROS production. We observed that all bisphenol derivatives cause an imbalance in some oxidant/antioxidant parameters. Bisphenols also caused significant DNA damage in order of BPF > BPA > BPS. We can suggest that both of the bisphenol derivatives used as alternatives to BPA also showed similar toxicities and may not be considered as safe alternatives. Mechanistic studies are needed to elucidate this issue.

The effects of bisphenols on the cardiovascular system ex vivo and in vivo

The human population is regularly exposed to bisphenols. The first compound of this class, bisphenol A, is burdened by numerous reports of its potential toxicity and has been hence replaced by its analogues, so-called next generation bisphenols. Their widespread use has made them pervasive throughout the environment. These endocrine disrupting chemicals can affect the cardiovascular system, and hence the aim of this study was to test 14 bisphenols (A, AF, AP, B, BP, C, E, F, G, M, P, PH, S and Z), and compare their effects in vitro (human and rat cell lines), ex vivo (isolated rat aorta) and in vivo (Wistar Han rats, acutely or chronically exposed to low environmental and high toxic doses). The majority of the tested bisphenols relaxed rat aorta, but their potency varied markedly. The most potent compound, bisphenol AF, had an EC₅₀ of 57 μM. The mechanism of action was likely based on the inhibition of calcium influx via L-type calcium channels. The cytotoxicity of bisphenols towards 4 human and rat cell lines (H9c2, A-10, MCF7/S0.5 and MCF7/182R-6) showed variable potencies ranging from units of micromolar to millimolar concentrations. Based on these data, an effect on arterial blood pressure and possible cardiotoxicity was expected. Contrarily, the in vivo acute effects of three doses (0.005, 0.05 and 2.5 mg/kg) of bisphenol AF and 3 other analogues (A, S and F) on the cardiovascular system were rather biologically negligible. The most potent bisphenol, AF, was also administered chronically at a dose of 2.5 mg/kg for 4 weeks to rats, but had no impact on arterial blood pressure. Our results showed that bisphenols can relax vascular smooth muscles, but the effective concentrations are too high to produce clear cardiovascular effects in relation to common biological exposure as was confirmed with the most potent bisphenol AF.

Effects of prenatal exposure to bisphenols on newborn leucocyte telomere length: a prospective birth cohort study in China

Telomere length (TL) at birth is related to diseases that may arise in the future and long-term health. Bisphenols exhibit toxic effects and can cross the placenta barrier. However, the effects of prenatal exposure to bisphenols on newborn TL remain unknown. We aimed to explore the effects of prenatal exposure to bisphenols (i.e., bisphenol A [BPA], bisphenol B [BPB], bisphenol F [BPF], bisphenol S [BPS] and tetrabromobisphenol A [TBBPA]) on relative TL in newborns. A total of 801 mother-infant pairs were extracted from the Guangxi Zhuang Birth Cohort. The relationship between bisphenol levels in maternal serum and relative TL in cord blood was examined by generalized linear models and restricted cubic spline (RCS) models. After adjusting for confounders, we observed a 3.19% (95% CI: -6.08%, -0.21%; P = 0.037) reduction in relative cord blood TL among mothers ≥ 28 years old, with each onefold increase in BPS. However, in each onefold increase of TBBPA, we observed a 3.31% (95% CI: 0.67%, 6.01%; P = 0.014) increase in relative cord blood TL among mothers < 28 years old. The adjusted RCS models revealed similar results (P overall < 0.05, P non-linear > 0.05). This study was the first to establish a positive association between serum TBBPA levels and relative TL in newborns born to young mothers. However, BPS levels were inversely correlated with TL in fetus born to old mothers. The results suggested that the fetus of old pregnant women may be more sensitive to BPS exposure. Moreover, BPS exposure early in life may accelerate aging or increase the risk of developing BPS-related diseases in later life.

[Bisphenol A and breast cancer: State of knowledge and meta-analysis]

INTRODUCTION

Bisphenol A is an endocrine disruptor used in the composition of food containers. It was partially banned in France in 2015 and classified as a "very high-risk substance" in 2017. Bisphenol A's carcinogenic effects have been demonstrated in animal testing. Bisphenol A acts through estrogen-dependent and estrogen-independent pathways. It induces epigenetic changes and impacts the microenvironment of the mammary gland. However, the role of bisphenol A exposure in the development of breast cancer in humans remains controversial. This study documents the current thinking on bisphenol A with an analysis of the mechanisms and a meta-analysis.

MATERIALS AND METHODS

A literature review and a statistical analysis of linear regression type, with the creation of a Forest plot, were used to perform the meta-analysis of 9 studies including 10,695 patients.

RESULTS

Nine case-control studies, published between 1990 and 2021, investigating the association between breast cancer and mean urinary, blood or tissue bisphenol A levels were selected. The meta-analysis did not find a significant association between bisphenol A exposure and the development of breast cancer with an OR=(1 IC95% [0.92-1.08]).

DISCUSSION

This meta-analysis does not show a link between breast cancer and bisphenol A exposure. Nevertheless, the analysis of a pathogenic link between bisphenol A and breast cancer requires additional cohort studies to conclude because of methods of available studies.

Bisphenols, but not phthalate esters, modulate gene expression in activated human MAIT cells in vitro

One route of human exposure to environmental chemicals is oral uptake. This is primarily true for chemicals that may leach from food packaging materials, such as bisphenols and phthalate esters. Upon ingestion, these compounds are transported along the intestinal tract, from where they can be taken up into the blood stream or distributed to mucosal sites. At mucosal sites, mucosal immune cells and in the blood stream peripheral immune cells may be exposed to these chemicals potentially modulating immune cell functions. In the present study, we investigated the impact of three common bisphenols and two phthalate esters on mucosal-associated invariant T (MAIT) cells in vitro, a frequent immune cell type in the intestinal mucosae and peripheral blood of humans. All compounds were non-cytotoxic at the chosen concentrations. MAIT cell activation was only slightly affected as seen by flow cytometric analysis. Phthalate esters did not affect MAIT cell gene expression, while bisphenol-exposure induced significant changes. Transcriptional changes occurred in ∼ 25 % of genes for BPA, ∼ 22 % for BPF and ∼ 8 % for BPS. All bisphenols down-modulated expression of CCND2, CCL20, GZMB and IRF4, indicating an effect on MAIT cell effector function. Further, BPA and BPF showed a high overlap in modulated genes involved in cellular stress response, activation signaling and effector function suggesting that BPF may not be safe substitute for BPA.

Adverse (geno)toxic effects of bisphenol A and its analogues in hepatic 3D cell model

Bisphenol A (BPA) is one of the most widely used and versatile chemical compounds in polymer additives and epoxy resins for manufacturing a range of products for human applications. It is known as endocrine disruptor, however, there is growing evidence that it is genotoxic. Because of its adverse effects, the European Union has restricted its use to protect human health and the environment. As a result, the industry has begun developing BPA analogues, but there are not yet sufficient toxicity data to claim that they are safe. We investigated the adverse toxic effects of BPA and its analogues (BPS, BPAP, BPAF, BPFL, and BPC) with emphasis on their cytotoxic and genotoxic activities after short (24-h) and prolonged (96-h) exposure in in vitro hepatic three-dimensional cell model developed from HepG2 cells. The results showed that BPFL and BPC (formed by an additional ring system) were the most cytotoxic analogues that affected cell viability, spheroid surface area and morphology, cell proliferation, and apoptotic cell death. BPA, BPAP, and BPAF induced DNA double-strand break formation (γH2AX assay), whereas BPAF and BPC increased the percentage of p-H3-positive cells, indicating their aneugenic activity. All BPs induced DNA single-strand break formation (comet assay), with BPAP (≥0.1 μM) being the most effective and BPA and BPC the least effective (≥1 μM) under conditions applied. The results indicate that not all of the analogues studied are safer alternatives to BPA and thus more in-depth research is urgently needed to adequately evaluate the risks of BPA analogues and assess their safety for humans.

Developmental and Reproductive Impacts of Four Bisphenols in Daphnia magna

Bisphenol A (BPA) is a typical endocrine-disrupting chemical (EDC) used worldwide. Considering its adverse effects, BPA has been banned or strictly restricted in some nations, and many analogs have been introduced to the market. In this study, we selected three representative substitutes, BPS, BPF, and BPAF, along with BPA, to assess the developmental and reproductive effects on Daphnia magna. The F0 generation was exposed to bisphenols (BPs) at an environmentally relevant concentration (100 μg/L) for 21 d; then the embryo spawn at day 21 was collected. Behavior traits, the activity of antioxidant enzymes, and gene transcription were evaluated at three developmental stages (days 7, 14, and 21). Notably, body length, heart rate, and thoracic limb beating were significantly decreased, and D. magna behaved more sluggishly in the exposed group. Moreover, exposure to BPs significantly increased the antioxidant enzymatic activities, which indicated that BPs activated the antioxidant defense system. Additionally, gene expression indicated intergenerational effects in larvae, particularly in the BPAF group. In conclusion, BPA analogs such as BPF and BPAF showed similar or stronger reproductive and developmental toxicity than BPA in D. magna. These findings collectively deepen our understanding of the toxicity of BPA analogs and provide empirical evidence for screening safe alternatives to BPA.

Bisphenols A and F, but not S, induce apoptosis in bovine granulosa cells via the intrinsic mitochondrial pathway

With the gradual decline in global fertility rates, there is a need to identify potential contributing factors, their mechanisms of actions and investigate possible solutions to reverse the trend. Endocrine disrupting compounds (EDCs), such as bisphenol A (BPA), are environmental toxicants that are known to negatively impact reproductive functions. As such, the use of BPA in the manufacturing industry has slowly been replaced by analogs, including bisphenol S (BPS) and bisphenol F (BPF), despite limited knowledge available regarding their impact on health and their safety. The following study investigates the effects of BPA, BPS and BPF at a concentration of 0.5 μg/mL and 50 μg/mL on bovine granulosa cell apoptosis, with the ultimate goal of determining how they may impact oocyte competence and, thus, overall fertility. The underlying hypothesis is that bisphenols disrupt the granulosa cell environment surrounding the oocyte inducing excessive apoptosis via the intrinsic mitochondrial pathway. To test this hypothesis, apoptosis was measured following a time- and dose-dependent exposure to all three bisphenols by flowcytometry paired with annexin V/PI staining as well as by quantification of key genes belonging to the intrinsic apoptotic pathway both at the mRNA and protein levels. The results of this study report that BPA and BPF reduce cell viability through reduced cell counts and increased apoptosis. This increase is due, in part, to the induction of apoptotic genes of the intrinsic pathway of apoptosis. Additionally, this study also suggests that BPS may not act on the intrinsic mitochondrial apoptotic pathway in bovine granulosa cells. Overall, this study allows us to establish potential apoptotic pathways activated by bisphenols as well as compare the relative apoptotic activities of BPA to its most widespread analogs.

Effects of bone marrow-derived mesenchymal stem cells exposed to endocrine-disrupting chemicals on the differentiation of umbilical cord blood hematopoietic stem cells

Endocrine-disrupting chemicals (EDCs), a class of peripheral toxic substances, can cause many environmental and clinical side effects, particularly on the human body's endocrine system. Bisphenol A (BPA) and diethylhexyl phthalate (DEHP) are two well-known EDCs in the medicine industry. However, there are no comprehensive studies on their effects on hematopoiesis. Hence, this study aimed to investigate the effect of these two aforementioned substances on the clonogenic capacity of umbilical cord blood hematopoietic stem cells (CB-HSCs). The HSCs which express CD34 + were isolated from umbilical cord blood by the magnetic-activated cell sorting (MACS) system. To investigate the effects of different optimized concentrations of BPA and DEHP, CB-CD34⁺ HSCs were exposed to EDCs in semisolid medium. For evaluation of coexposures, CB-CD34⁺ HSCs were cocultured with bone marrow-derived mesenchymal stem cells (BM-MSCs) in the presence of BPA and DEHP. Finally, the number and types of colonies were evaluated after 14 days. Statistical analysis was performed by GraphPad Prism through ANOVA. CB-HSC treated by BPA and DEHP showed a lower absolute colony count than the control group (P < 0.05). Decrease in clonogenic potential of HSCs was more significant in coculture condition by MSCs. In particular, there was a significant decrease in the BFU-E colonies in comedicated-derived fractions (P < 0.0001). In the presence of EDCs such as BPA and DEHP, the patterns of differentiation in CD34⁺ CB-HSCs changed from suppressed erythroid differentiation toward stimulated myelogenesis pathways.

Influence of aryl hydrocarbon receptor and sulfotransferase 1A1 on bisphenol AF-induced clastogenesis in human hepatoma cells

Bisphenol compounds (BPs) are ubiquitously existing pollutants. Recent evidence shows that they may be activated by human CYP1A1 for clastogenic effects; however, factors that influence/mediate CYP1A1-activated 4,4'-(hexafluoroisopropylidene)diphenol (BPAF) toxicity, particularly the aryl hydrocarbon receptor (AhR), sulfotransferase (SULT) 1A1 [known to conjugate 2,2-bis(4-hydroxyphenol)-propane (BPA)] and reactive oxygen species (ROS), remain unclear. In this study, a human hepatoma (HepG2) cell line was genetically engineered for the expression of human CYP1A1 and SULT1A1, producing HepG2-hCYP1A1 and HepG2-hSULT1A1, respectively. They were used in the micronucleus test and γ-H2AX analysis (Western blot) (indicating double-strand DNA breaks) with BPAF; the role of AhR in mediating BPAF toxicity was investigated by coexposure of AhR modulators in HepG2 and its derivative C3A (with no genetic modifications but enhanced CYP expression). The results indicated induction of micronuclei by BPAF (≥ 2.5 µM, for 2-cell cycle) in HepG2-hCYP1A1 and C3A, while inactive in HepG2 and HepG2-hSULT1A1; however, BPAF induced micronuclei in HepG2 pretreated with 3,3',4,4',5-pentachlorobiphenyl (PCB126, AhR activator), and BAY-218 (AhR inhibitor) blocked the effect of BPAF in C3A. In HepG2-hCYP1A1 BPAF selectively induced centromere-free micronuclei (immunofluorescent assay) and double-strand DNA breaks. In HepG2 cells receiving conditional medium from BPAF-HepG2-hCYP1A1 incubation micronuclei were formed, while negative in HepG2-hSULT1A1. Finally, the intracellular levels of ROS, superoxide dismutase and reduced glutathione in C3A and HepG2-hCYP1A1 exposed to BPAF were all moderately increased, while unchanged in HepG2 cells. In conclusion, like other BPs BPAF is activated by human CYP1A1 for potent clastogenicity, and this effect is enhanced by AhR while alleviated by SULT1A1.

A systematic comparison of neurotoxicity of bisphenol A and its derivatives in zebrafish

As more and more countries have prohibited the manufacture and sale of plastic products with bisphenol A (BPA), a number of bisphenol analogues (BPs), including BPS, BPF and BPAF, have gradually been used as its primary substitutes. Ideally, substitutes used to replace chemicals with environmental risks should be inert, so it makes sense that the risk of the similar chemical substitutes (BPS, BPF, and BPAF) should be assessed before they used. Therefore, in the present study, the neurotoxicity of four BPs at environmentally relevant concentration (200 μg/L) were systematically compared using zebrafish as a model. Our results showed that the four BPs (BPA, BPS, BPF and BPAF) exhibited no obvious effect on the hatchability, survival rate and body length of zebrafish larvae, noteworthily a significant inhibitory effect on spontaneous movement at 24 hpf was observed in the BPA, BPF and BPAF treatment groups. Behavioral tests showed that BPAF, BPF and BPA exposure significantly reduced the locomotor activity of the larvae. Additionally, BPAF treatment adversely affected motor neuron axon length in transgenic lines hb9-GFP zebrafish and decreased central nervous system (CNS) neurogenesis in transgenic lines HuC-GFP zebrafish. Intriguingly, BPAF displayed the strongest effects on the levels and metabolism of neurotransmitters, followed by BPF and BPA, while BPS showed the weakest effects on neurotransmitters. In conclusion, our study deciphered that environmentally relevant concentrations of BPs exposure exhibited differential degrees of neurotoxicity, which ranked as below: BPAF > BPF ≈ BPA > BPS. The possible mechanisms can be partially ascribed to the dramatical changes of multiple neurotransmitters and the inhibitory effects on neuronal development. These results suggest that BPAF and BPF should be carefully considered as alternatives to BPA.

MAIT cell activation is reduced by direct and microbiota-mediated exposure to bisphenols

Oral uptake is the primary route of human bisphenol exposure, resulting in an exposure of the intestinal microbiota and intestine-associated immune cells. Therefore, we compared the impact of bisphenol A (BPA), bisphenol F (BPF) and bisphenol S (BPS) on (i) intestinal microbiota, (ii) microbiota-mediated immunomodulatory effects and (iii) direct effects on mucosal-associated invariant T (MAIT) cells in vitro. We acutely exposed human fecal microbiota, Bacteroides thetaiotaomicron and Escherichia coli to BPA and its analogues BPF and BPS referring to the European tolerable daily intake (TDI), i.e. 2.3 µg/mL, 28.3 µg/mL and 354.0 µg/mL. Growth and viability of E. coli was most susceptible to BPF, whereas B.thetaiotaomicron and fecal microbiota were affected by BPA > BPF > BPS. At 354.0 µg/mL bisphenols altered microbial diversity in compound-specific manner and modulated microbial metabolism, with BPA already acting on metabolism at 28.3 µg/mL. Microbiota-mediated effects on MAIT cells were observed for the individual bacteria at 354.0 µg/mL only. However, BPA and BPF directly modulated MAIT cell responses at low concentrations, whereby bisphenols at concentrations equivalent for the current TDI had no modulatory effects for microbiota or for MAIT cells. Our findings indicate that acute bisphenol exposure may alter microbial metabolism and impact directly on immune cells.

Organism and molecular-level responses of superoxide dismutase interaction with 2-pentanone

2-Pentanone is an excellent organic solvent and extractant, which is widely used in industrial production. 2-Pentanone is harmful to soil organisms when it enters the soil. However, current studies have not clarified the response of the antioxidant enzyme superoxide dismutase (SOD) to 2-Pentanone and its mechanism. In this study, the response of earthworm antioxidant enzyme SOD to 2-Pentanone and its molecular mechanism was investigated at organism molecular levels. The results showed that the SOD activity of earthworms under 2-Pentanone stress was significantly inhibited, and the inability of superoxide anion radicals (·O₂^-) to be scavenged in time might be one of the reasons for the increase of lipid peroxidation. Under 2-Pentanone exposure conditions, catalase (CAT), an antioxidant enzyme closely related to SOD, and the total antioxidant capacity (T-AOC) of earthworms were activated to resist oxidative damage. On the other hand, the observation of earthworm microstructure provided evidence of a direct risk of 2-Pentanone on earthworm body wall tissues. Molecular-level assays have shown that 2-pentanone altered the secondary structure of SOD, which further led to the loosening of the SOD backbone structure and the extension of the polypeptide chain. On the other hand, 2-pentanone quenched the endogenous fluorescence of SOD in the form of static quenching and formed the 2-pentanone/SOD complex. Molecular simulation results suggested that 2-pentanone tended to bind on the surface of SOD rather than close to the active site, and it is speculated that the alteration of SOD structure is the key reason for the change in its activity. This study enriches the toxicological data of 2-Pentanone on soil organisms, thus responding to the current concerns about its ecological risk.

Teratogenicity and toxicity of the new BPA alternative TMBPF, and BPA, BPS, and BPAF in chick embryonic development

Bisphenol A (BPA) is a widely known, yet controversial reproductive toxin, capable of inducing reproductive, developmental, and somatic growth defects across species. Due to scientific findings and public concern, companies have developed BPA alternatives remarkably similar to BPA. However, these alternatives have had much less testing and oversight, yet they are already being mass-produced and used across industries from plastics to food-contact coatings. The newest one, tetramethyl bisphenol F (TMBPF), is the least well-studied and has never been investigated in embryological models, however it continues to be mass produced and found in various products. Here, we used the chicken embryotoxicity screening test to compare the toxicities and potencies of several BPA analogs including TMBPF. We exposed developing chicken (Gallus gallus domesticus) embryos in ovo, from embryonic day 5 to 12 (E5-12), to increasing concentrations of BPA, bisphenol S (BPS), bisphenol AF (BPAF), and TMBPF, from 0.003 to 30 μM, and analyzed their developmental and toxic effects. The bisphenols significantly impaired development, growth, and survival in a dose-dependent manner, even at low, environmentally relevant concentrations of 3-30 nM. There was severely reduced growth and developmental delay, with exposed embryos averaging half the size and weight of control vehicle-treated embryos. The most common and severe dysmorphologies were craniofacial, eye, gastrointestinal, and body pigmentation abnormalities. The bisphenols caused dose-dependent toxicity with the lowest LC₅₀s (lethal concentration with 50% survival) ever demonstrated in chick embryos, at 0.83-2.92 μM. Notably, TMBPF was the second-most toxic and teratogenic of all chemicals tested (rank order of BPAF > TMBPF > BPS > BPA). These results underscore the adverse effects of BPA replacements on early embryo development and may have implications for reproductive health and disease across species, including pregnancy exposures in humans.

The occurrence of selected endocrine-disrupting chemicals in water and sediments from an urban lagoon in Southern Italy

Endocrine-disrupting chemicals (EDCs) are agents able to exert perturbation toward the endocrine system via a broad array of signalling pathways. Some EDCs are released into the environment as a result of antropogenic activities. Analytical surveillance plays a critical role in investigating the prevalence of such chemicals in environmental samples. A study was carried out in a lagoon in Southern Italy, a water basin relates to the sea through a mouth channel, making this water body a "dynamic environment". The screening of fourteen EDCs in surface waters and sediments, includes a fast and cost-effective sample preparation, based on a solid-liquid (sediments) and liquid-liquid (surface waters) extraction and a chromatographic analysis by liquid chromatography tandem UV and fluorescence detection. Only four chemicals out the fourteen investigated EDCs were detected in both matrices with a frequency higher than 60%. The average concentrations of the single EDC were higher in sediments (730-155.000 ng kg^-1  dw) than in surface waters (132-28.000 ng L^-1 ). Limited to the assayed EDCs, the ecosystem has a low risk regarding to the conservation of biodiversity of the animal species living thereby, since the total estrogenic activity does not exceed 1 ng L^-1 . PRACTITIONER POINTS: Occurrence of selected EDCs was investigated in an Italian lagoon in Southern Italy. BPAF, BADGE, and BPA were the most frequently and highly detected compounds in both waters and sediments. Concentration levels were greater in the sediment than in water samples. Low risk for the ecosystem biodiversity concerning investigated EDCs.

Effective activation of peroxymonosulfate with natural manganese-containing minerals through a nonradical pathway and the application for the removal of bisphenols

Synthetic manganese oxides had been widely investigated to activate peroxymonosulfate (PMS) for contaminant removal in recent years. The generation of reactive oxygen species (ROS, e.g., radicals) was believed to be the primary PMS activation pathways. In this work, we report that natural manganese-containing minerals (NMMs) were also effective for PMS activation to degrade bisphenols in water. Moreover, a nonradical pathway different from literatures, was confirmed according to scavenging tests, electron paramagnetic resonance (EPR) characterization, chemical probing, solvent exchange, and Raman and electrochemical analysis. It was verified that PMS complexed with the mineral surface via inner-sphere interaction. This surface interaction improved its reactivity towards the probe compounds, bisphenols. Taking bisphenol AF (BPAF) as an example, its degradation rate was related to surface area and dosages of the mineral. Water constituents such as Cl^-, HCO₃^-, and NOM had negligible impact on BPAF removal. The activity of the mineral was kept in an 80-hour continuous flow test. The PMS/NMM coupled oxidation degraded BPAF through direct electron transfer, and the degradation intermediates further underwent hydroxylation, bond cleavage, H-atom substitution, aromatic ring-opening, and decarboxylation. Consequently, eco-toxicity of BPAF can be reduced during the oxidation.

Structural Compactness in Hen Egg White Lysozyme Induced by Bisphenol S: A Spectroscopic and Molecular Dynamics Simulation Approach

The endocrine disrupting compound Bisphenol and its analogues are widely used in food packaging products and can cause serious health hazards. The protein, Lysozyme (Lyz), showing anti-microbial properties, is used as a "natural" food and dairy preservative. Herein, we explored the interaction between Lyz and Bisphenol S (BPS) by multi-spectroscopic and theoretical approaches. Lyz interacts with BPS through static quenching, where hydrophobic force governed the underlying interaction. Molecular docking results reveal that tryptophan plays a vital role in binding, corroborated well with near UV-CD studies. A decrease in the radius of gyration (from 1.43 nm to 1.35 nm) of Lyz substantiates the compactness of the protein conformation owing to such an interaction. This structural alteration experienced by Lyz may alter its functional properties as a food preservative. Consequently, this can degrade the quality of the food products and thereby lead to severe health issues.

BPA and BPA alternatives BPS, BPAF, and TMBPF, induce cytotoxicity and apoptosis in rat and human stem cells

Bisphenol A (BPA) is a ubiquitous industrial chemical found in everyday plastic products and materials. Due to scientific findings on the reproductive, developmental, and cellular defects caused by BPA and heightened public awareness, manufacturers have begun to use new chemicals in place of BPA in "BPA-free" products. These alternatives are chemical analogs of BPA and include dozens of new compounds that have undergone relatively little testing and oversight, including: bisphenol S (BPS), bisphenol AF (BPAF), and the recently developed tetramethyl bisphenol F (TMBPF; the monomer of valPure V70). Here, we used adult female rat adipose-derived stem cells (rASCs) and human mesenchymal stem cells (hMSCs) to compare the toxicities and potencies of these BPA alternatives in vitro. Rat and human stem cells were exposed to BPA (1-10 μM), 17β-estradiol (E2; 10 μM), BPS (1-100 μM), BPAF (3×10^-4-30 μM), TMBPF (0.01-50 μM), or control media alone (with 0.01% ethanol) for varying time intervals from 10 min to 24 h. We found significantly decreased cell viability and massive apoptosis in rat and human stem cells treated with each BPA analog, as early as 10 min of exposure, and at low, physiologically relevant doses. BPAF showed extreme cytotoxicity in a dose-dependent manner (LC₅₀ =0.014 μM (rASCs) and 0.009 μM (hMSCs)), whereas TMBPF showed a bimodal response, with low and high concentrations being the most toxic (LC₅₀ =0.88 μM (rASCs) and 0.06 μM (hMSCs)). Activated caspase-6 levels increased in nearly all cells treated with the BPA analogs indicating the majority of cell death was due to caspase-6-mediated apoptosis. These results in both rat and human stem cells underscore the toxicity and potency of these BPA analogs, and establish a rank order of potency of: BPAF>TMBPF>BPA>BPS. Further, these and other recent findings indicate that these newer BPA analogs may be 'regrettable substitutions,' being worse than the original parent compound and lacking proper testing and regulation. This work brings to light the need for further toxicological characterization, better regulation, greater public awareness, and the development of safer, more sustainable chemicals and non-plastic products.

Effects of bisphenol S and bisphenol F on human spermatozoa: An in vitro study

Bisphenol A (BPA), the main chemical monomer of epoxy resins and polycarbonate plastics, has generated concerns about its endocrine disruptor properties, along with the reported possible links with several human health disorders. Accordingly, some restrictions on its use have been recommended. Bisphenol S (BPS) and bisphenol F (BPF) are the main replacements to BPA, with which they share homologies in chemical structure. However, to date, little is known about their possible adverse effects for human reproduction. As the in vitro exposure of human spermatozoa to BPA induces oxidative/pro-apoptotic effects, the aim of the present study was to verify whether BPS and BPF could represent safer compounds for human sperm functions. The exposure of motile sperm suspensions to scalar concentrations of BPS or BPF for 4 h did not significantly reduce sperm motility (as assessed by computer-aided semen analysis) and viability. At flow cytometry, no changes in mitochondrial membrane potential, or mitochondrial generation of reactive oxygen species were detected by using the JC-1 and MitoSOX red probes, respectively. Interestingly, it nor even the combination of both BPS and BPF at the highest concentrations impaired sperm mitochondrial functions. In conclusion, BPS and BPF seem to be safer alternatives to BPA for sperm biology, as they do not affect mitochondrial functions, sperm motility and viability. These findings could help regulatory agencies to identify more secure chemicals to replace BPA in industrial production of plastics.

Bisphenol F Exposure in Adolescent Heterogeneous Stock Rats Affects Growth and Adiposity

Bisphenol F (BPF) is increasingly substituting bisphenol A in manufacturing polycarbonates and consumer products. The cardiometabolic effects of BPF in either humans or model organisms are not clear, and no studies to date have investigated the role of genetic background on susceptibility to BPF-induced cardiometabolic traits. The primary goal of this project was to determine if BPF exposure influences growth and adiposity in male N:NIH heterogeneous stock (HS) rats, a genetically heterogeneous population. Littermate pairs of male HS rats were randomly exposed to either vehicle (0.1% ethanol) or 1.125 µg/ml BPF in 0.1% ethanol for 5 weeks in drinking water starting at 3 weeks-of-age. Water consumption and body weight was measured weekly, body composition was determined using nuclear magnetic resonance, urine and feces were collected in metabolic cages, and blood and tissues were collected at the end of the study. BPF-exposed rats showed significantly increased body growth and abdominal adiposity, risk factors for cardiometabolic disease. Urine output was increased in BPF-exposed rats, driving a trend in increased creatinine clearance. We also report the first relationship between a bisphenol metabolizing enzyme and a bisphenol-induced phenotype. Preliminary heritability estimates of significant phenotypes suggest that BPF exposure may alter trait variation. These findings support BPF exposure as a cardiometabolic disease risk factor and indicate that the HS rat will be a useful model for dissecting gene by BPF interactions on metabolic health.

BPA, BPAF and TMBPF Alter Adipogenesis and Fat Accumulation in Human Mesenchymal Stem Cells, with Implications for Obesity

Bisphenol A (BPA) is an endocrine-disrupting chemical used in the production of plastics, and is linked to developmental, reproductive, and metabolic disorders including obesity. Manufacturers have begun using ‘BPA-free’ alternatives instead of BPA in many consumer products. However, these alternatives have had much less testing and oversight, yet they are already being mass-produced and used across industries from plastics to food-contact coatings. Here, we used human female adipose-derived stem cells (hASCs), a type of adult mesenchymal stem cell, to compare the effects of BPA and BPA alternatives on adipogenesis or fat cell development in vitro. We focused on two commonly used BPA replacements, bisphenol AF (BPAF) and tetramethyl bisphenol F (TMBPF; monomer of the new valPure V70 food-contact coating). Human ASCs were differentiated into adipocytes using chemically defined media in the presence of control differentiation media with and without 17β-estradiol (E2; 10 μM), or with increasing doses of BPA (0, 0.1 and 1 μM), BPAF (0, 0.1, 1 and 10 nM), or TMBPF (0, 0.01 and 0.1 μM). After differentiation, the cells were stained and imaged to visualize and quantify the accumulation of lipid vacuoles and number of developing fat cells. Treated cells were also examined for cell viability and apoptosis (programmed cell death) using the respective cellular assays. Similar to E2, BPA at 0.1 μM and BPAF at 0.1 nM, significantly increased adipogenesis and lipid production by 20% compared to control differentiated cells (based on total lipid vacuole number to cell number ratios), whereas higher levels of BPA and BPAF significantly decreased adipogenesis (p < 0.005). All tested doses of TMBPF significantly reduced adipogenesis and lipid production by 30–40%, likely at least partially through toxic effects on stem cells, as viable cell numbers decreased and apoptosis levels increased throughout differentiation. These findings indicate that low, environmentally-relevant doses of BPA, BPAF, and TMBPF have significant effects on fat cell development and lipid accumulation, with TMBPF having non-estrogenic, anti-adipogenic effects. These and other recent results may provide a potential cellular mechanism between exposure to bisphenols and human obesity, and underscore the likely impact of these chemicals on fat development in vivo.

Chronic exposure of bisphenol S (BPS) affect hypothalamic-pituitary-testicular activities in adult male rats: possible in estrogenic mode of action

Background

The industrial revolution has resulted in increased synthesis and the introduction of a variety of compounds into the environment and their potentially hazardous effects have been observed in the biota. The present study was aimed to evaluate the potential endocrine-disrupting effects of chronic exposure to the low concentrations of bisphenol S (BPS) in male rats.

Methods

Weaning male Sprague-Dawley rats (22 days old) were either exposed to water containing 0.1% ethanol for control or different concentrations of BPS (0.5, 5, and 50 μg/L) in drinking water for 48 weeks in the chronic exposure study. After completion of the experimental period, animals were dissected and different parameters (hormone concentrations, histology of testis and epididymis, oxidative stress and level of antioxidant enzymes in the testis, daily sperm production (DSP), and sperm parameters) were determined.

Results

Results of the present study showed a significant alteration in the gonadosomatic index (GSI) and relative reproductive organ weights. Oxidative stress in the testis was significantly elevated while sperm motility, daily sperm production, and the number of sperm in epididymis were reduced. Plasma testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) concentrations were reduced and estradiol levels were high in the 50 μg/L-exposed group. Histological observations involved a significant reduction in the epithelial height of the testis along with disrupted spermatogenesis, an empty lumen of the seminiferous tubules, and the caput region of the epididymis.

Conclusion

These results suggest that exposure to 5 and 50 μg/L of BPS for the chronic duration started from an early age can induce structural changes in testicular tissue architecture and endocrine alterations in the male reproductive system which may lead to infertility in males.

Endocrine Disruptor Potential of Short- and Long-Chain Perfluoroalkyl Substances (PFASs)-A Synthesis of Current Knowledge with Proposal of Molecular Mechanism

Endocrine disruptors are a group of chemical compounds that, even in low concentrations, cause a hormonal imbalance in the body, contributing to the development of various harmful health disorders. Many industry compounds, due to their important commercial value and numerous applications, are produced on a global scale, while the mechanism of their endocrine action has not been fully understood. In recent years, per- and polyfluoroalkyl substances (PFASs) have gained the interest of major international health organizations, and thus more and more studies have been aimed to explain the toxicity of these compounds. PFASs were firstly synthesized in the 1950s and broadly used in the industry in the production of firefighting agents, cosmetics and herbicides. The numerous industrial applications of PFASs, combined with the exceptionally long half-life of these substances in the human body and extreme environmental persistence, result in a common and chronic exposure of the general population to their action. Available data have suggested that human exposure to PFASs can occur during different stages of development and may cause short- or/and long-term health effects. This paper synthetizes the current literature reports on the presence, bioaccumulation and, particularly, endocrine toxicity of selected long- and short-chain PFASs, with a special emphasis on the mechanisms underlying their endocrine actions.

Physiological and metabolic approach of plastic additive effects: Immune cells responses

Human and wildlife are continually exposed to a wide range of compounds and substances, which reach the body through the air, water, food, or personal care products. Plasticizers are compounds added to plastics and can be released to the environment under certain conditions. Toxicological studies have concluded that plasticizers, phthalates, and bisphenols are endocrine disruptors, alter the endocrine system and functioning of the immune system and metabolic process. A functional immune response indicates favourable living conditions for an organism; conversely, a weak immune response could reveal a degraded environment that requires organisms to adapt. There is growing concern about the presence of plastic debris in the environment. In this review, the current knowledge of the action of plasticizers on leukocyte cells will be itemized. We also point out critically the role of some nuclear and membrane receptors as key players in the action of plasticizers on cells possess immune function. We discuss the role of erythrocytes within the immune responses and the alteration caused by plasticizers. Finally, we highlight data evidencing mitochondrial dysfunctions triggered by plasticizing toxic action, which can lead to immunosuppression.

Oxidative Stress, Endocrine Disturbance, and Immune Interference in Humans Showed Relationships to Serum Bisphenol Concentrations in a Dense Industrial Area

Bisphenol A (BPA) analogues, used in a range of products due to health concerns regarding BPA, have emerged as ubiquitous environmental contaminants worldwide. This study aims to evaluate the levels of nine bisphenols (BPs) and eight biomarkers (malondialdehyde, MDA; 8-hydroxy-2'-deoxyguanosine, 8-OHdG; estradiol, E2; follicle-stimulating hormone, FSH; luteinizing hormone, LH; complement compound 3, C3; immunoglobulin M, IgM and c-reaction protein, CRP) in human serum (n = 353) to explore their potential relationships. The detection rates (DRs) of eight BPs in serum samples taken from people working in a dense industrial area of Shenzhen (Guangdong Province, China) were over 72% except for bisphenol B (BPB) (DR = 27.5%). The mean concentrations of BPA, bisphenol P (BPP), BPB, bisphenol F (BPF), bisphenol FL (BPFL), 4,4'-dihydroxy-benzophenone (DHBP), bisphenol AF (BPAF), 4,4'-thiodiphenol (TDP) and bisphenol S (BPS) were 42.062, 2.083, 0.765, 0.578, 0.423, 0.402, 0.191, 0.120, and 0.071 ng/mL, respectively. BPA and BPFL were significantly correlated with the level of oxidative stress indices MDA and 8-OHdG; BPAF, BPB, and DHBP were strongly correlated with the level of endocrine disturbance indices E2, FSH, and LH; and BPF, DHBP, and BPAF were apparently related to the level of immune interference indices C3 and IgM. This study also suggests multiple impacts (oxidative stress, endocrine disturbance, and immune interference) mediated by BPs contaminants in vivo. To our knowledge, this is the first study to report the correlations among these nine serum BPs and oxidative stress and endocrine and immune system indices in human serum samples collected from dense industrial areas.

Bisphenol AF induces apoptosis via estrogen receptor beta (ERβ) and ROS-ASK1-JNK MAPK pathway in human granulosa cell line KGN

Bisphenol AF (BPAF) is an emerging environmental pollutant. Although BPAF is widely spread in the environment and human surroundings, its interference with ovarian function has not been fully elucidated. The aim of this study was to identify the mechanism underlying the effect of BPAF on the apoptosis of KGN cells, which maintain the physiological characteristics of ovarian granulosa cells. Our results indicated that BPAF induces KGN cell apoptosis in a concentration- and time-dependent manner. Meanwhile, BPAF exposure significantly promoted the expression of pro-apoptotic proteins, including Bax, Bid and Bak, while the expression of anti-apoptotic proteins, such as Bcl-2, Bcl-xL and Mcl-1, decreased significantly. We further detected a significant increase in intracellular ROS levels in response to high concentrations of BPAF exposure. After blocking the corresponding pathway, it was found that ROS mediates ASK1 and JNK activation. Furthermore, the role of Ca²⁺ overload and estrogen receptor β (ERβ) in BPAF-induced KGN cell apoptosis was also confirmed by using inhibitors. These results suggest that BPAF has potential reproductive toxicity for females, and ROS-ASK1-JNK axis may play a key role in BPAF-induced ovarian dysfunction. In addition, Ca²⁺ overload and ERβ pathway activation may also be an important mechanism of reproductive toxicity of BPAF.

Sex-specific oxidative damage effects induced by BPA and its analogs on primary hippocampal neurons attenuated by EGCG

BPA analogs, including bisphenol S (BPS) and bisphenol B (BPB), have been used to replace BPA since it was banned to be added. To investigate whether BPA and its analogs cause oxidative damage effects on primary hippocampal neurons of rats, reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), mitochondrial membrane potential (MMP), apoptosis and cell viability assays were conducted after hippocampal neurons exposure to different concentrations of BPA, BPS, and BPB (1, 10, 100 nM and 1, 10, 100 μM). Moreover, the effects of EGCG (5 and 6 μM for male and female, respectively) added on neurons exposed to BPA were assessed. Results showed that 24 h exposure to these bisphenols (BPs) could increase the levels of ROS and contents of MDA, but reduce the activity of SOD significantly. A decline of cell viabilities accompanied with the increasing of apoptosis rates was observed after 7 d exposure to BPs and the reduction of MMP was also observed after 7 d exposure to BPA. Interestingly, BPS has the lower toxicity to hippocampal neurons compared with BPA and BPB. Non-monotonic dose-effect relationships between the concentrations of BPs and the cytotoxic effects were observed, and the effects of BPs on male hippocampal neurons are greater than those of female ones in general. While EGCG can protect neurons free of oxidative damages. In conclusion, the results suggest that BPs may induce sex-specific neurotoxic effects involving oxidative stress, which can be attenuated by EGCG, and males are more sensitive to BPs than females.

PLHC-1 topminnow liver cells: An alternative model to investigate the toxicity of plastic additives in the aquatic environment

Plasticizers are widespread environmental contaminants that have been described as obesogens in terrestrial vertebrates. However, its effects on fish lipids homeostasis are almost unknown. This work explores the use of PLHC-1 cells as an alternative model to assess the disruption of hepatic lipids by plastic additives and to gather information on the mode of action of these chemicals in fish. PLHC-1 lipid extracts were analyzed by flow injection coupled to high resolution mass spectrometry (FIA-ESI(+/-)-Orbitrap-Exactive) after 24 h exposure of the cells to the selected plasticizers: dibutyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), bisphenol F (BPF), and chlorinated bisphenol A diglycidyl ether (BADGE·2HCl). The analysis of the culture medium and the intracellular concentration of the chemicals revealed the highest bioconcentration of BADGE·2HCl, DBP and DEHP, which was in agreement with the strongest alteration of the cells lipidome. BADGE·2HCl induced a significant depletion of triacylglycerides (TGs), while DEHP and DBP stimulated the accumulation of TGs. Exposure to BPF induced the generation of reactive oxygen species in PLHC-1 cells and a significant depletion of phosphatidylcholine (PC)- and phosphatidylethanolamine (PE)-plasmalogens, and TGs (cell depots of polyunsaturated fatty acids). Overall, this study evidences different modes of action of plastic additives in topminnow liver cells, describes differential lipidomic signatures, and highlights the higher lipotoxicity of BADGE·2HCl and BPF compared to BPA.

Prenatal exposure to bisphenol S and altered newborn mitochondrial DNA copy number in a baby cohort study: Sex-specific associations

Bisphenol S (BPS) is a main substitute for bisphenol A, which are ubiquitous in human daily products. Newborn mitochondrial DNA copy number (mtDNAcn) is considered as a marker for biological aging and human health, and has been related to diseases in later life. We recruited 762 mother-newborn pairs in a birth cohort study between 2013 and 2015 in Wuhan, China. Urinary BPS concentrations were detected using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). MtDNAcn from cord blood was measured by quantitative real-time polymerase chain reaction (qPCR). We applied multiple informant models based on generalized estimating equations to assess the associations between prenatal BPS exposure and mtDNAcn. The median urine concentrations of BPS were 0.32 μg/L, 0.34 μg/L, and 0.36 μg/L in the first, second, and third trimesters, respectively. In the multiple informant models, we observed significant associations between BPS and mtDNAcn among male newborns. Compared with the lowest quarters, the second, third, and the highest quarter of BPS level were associated with 58.00% (95% CI: 76.58%, -24.66%), 64.65% (95% CI: 79.40%, -39.33%) and 59.07% (95% CI: 75.16%, -32.58%) reductions of mtDNAcn in the first trimester, respectively. No significant associations were found in the second and third trimesters. The associations between BPS and mtDNAcn were not found among female newborns. Findings from this study suggested that BPS exposure was related to decreased mtDNAcn in male newborns. The first trimester was identified as the critical windows for BPS exposure during pregnancy.

Bisphenol A and Bisphenol S Induce Endocrine and Chromosomal Alterations in Brown Trout

Bisphenol A is a widely used compound found in large amount of consumer products. As concerns have been raised about its toxicological and public health effect, the use of alternatives to bisphenol A are now increasing. Bisphenol S is one of the analogues being used as a replacement for bisphenol A despite the fact that little is known about the effects of bisphenol S on living organisms. In this study, we investigated the potential endocrine and genotoxic effects of bisphenol A and bisphenol S in juvenile brown trout (Salmo trutta). The fish were exposed to the compounds for either 2 weeks or 8 weeks via sustained-release cholesterol implants containing doses of 2 mg/kg fish or 20 mg/kg fish of the substances. The effects on the thyroid hormone levels and the estrogenic disrupting marker vitellogenin were evaluated, along with the genotoxic markers micronucleated cells and erythrocyte nuclear abnormalities. An increase in plasma vitellogenin was observed in fish exposed to the high dose of bisphenol A for 2 weeks. At this experimental time the level of the thyroid hormone triiodothyronine (T3) in plasma was elevated after bisphenol S exposure at the high concentration, and paralleled by an increase of micronucleated cells. Moreover, bisphenol A induced an increase of micronuclei frequency in fish erythrocytes after the exposure at the lowest dose tested. Taken together the results indicate that both bisphenol A and its alternative bisphenol S cause endocrine disrupting and genotoxic effects in brown trout, although suggesting two different mechanisms of damage underlying bisphenol A and bisphenol S activity.

Tetrabromobisphenol A, terabromobisphenol S and other bromophenolic flame retardants cause cytotoxic effects and induce oxidative stress in human peripheral blood mononuclear cells (in vitro study)

Brominated flame retardants (BFRs) are the compounds used in the industry in order to decrease flammability of various everyday products. The use of BFRs leads to migration of these substances into the environment, which results in the exposure of humans to their action. Although BFRs are widespread in human surrounding, the effect of these compounds on human body has been very poorly assessed. The purpose of this study was to evaluate cytotoxic effects as well as oxidative potential of selected bromophenolic flame retardants such as tetrabromobisphenol A (TBBPA), tetrabromobisphenol S (TBBPS), 2,4,6-tribromophenol (2,4,6-TBP) and pentabromophenol (PBP) on human peripheral blood mononuclear cells (PBMCs) that are crucial for proper functioning of the immune system. The cells were treated with the substances studied in the concentrations ranging from 0.0001 to 100 μg/mL for 1 h or 24 h. The results have shown that the compounds examined reduced PBMCs viability and ATP level as well as increased reactive oxygen species (including hydroxyl radical) formation. Moreover, the substances tested induced lipid peroxidation and caused oxidative damage to proteins in the incubated cells. It has also been noticed that the greatest changes were provoked by tetrabromobisphenol A, while the weakest by TBBPS, which is used as a substitute of TBBPA in the manufacture.

A comprehensive review of the neurobehavioral effects of bisphenol S and the mechanisms of action: New insights from in vitro and in vivo models

The normal brain development and function are delicately driven by an ever-changing milieu of steroid hormones arising from fetal, placental, and maternal origins. This reliance on the neuroendocrine system sets the stage for the exquisite sensitivity of the central nervous system to the adverse effects of endocrine-disrupting chemicals (EDCs). Bisphenol A (BPA) is one of the most common EDCs which has been a particular focus of environmental concern for decades due to its widespread nature and formidable threat to human and animal health. The heightened regulatory actions and the scientific and public concern over the adverse health effects of BPA have led to its replacement with a suite of structurally similar but less known alternative chemicals. Bisphenol S (BPS) is the main substitute for BPA that is increasingly being used in a wide array of consumer and industrial products. Although it was considered to be a safe BPA alternative, mounting evidence points to the deleterious effects of BPS on a wide range of neuroendocrine functions in animals. In addition to its reproductive toxicity, recent experimental efforts indicate that BPS has a considerable potential to induce neurotoxicity and behavioral dysfunction. This review analyzes the current state of knowledge regarding the neurobehavioral effects of BPS and discusses its potential mode of actions on several aspects of the neuroendocrine system. We summarize the role of certain hormones and their signaling pathways in the regulation of brain and behavior and discuss how BPS induces neurotoxicity through interactions with these pathways. Finally, we review potential links between BPS exposure and aberrant neurobehavioral functions in animals and identify key knowledge gaps and hypotheses for future research.

Association of bisphenol A or bisphenol S exposure with oxidative stress and immune disturbance among unexplained recurrent spontaneous abortion women

Human exposure to environmental chemicals might play a role in the pathogenesis of unexplained recurrent spontaneous abortion (URSA). Bisphenol A (BPA) and bisphenol S (BPS) have been suggested to affect reproductive health. However, the mechanism remains unclear. To explore the association between BPA and BPS exposure and oxidative stress and immune homeostasis, we conducted a cross-sectional study and revealed BPA and BPS levels in relation to these two factors which were supposed to be implicated in miscarriage. 111 URSA patients were recruited and we analyzed urinary BPA and BPS concentrations, oxidative stress biomarkers (8-hydroxydeoxyguanosine and 8-isoprostane) and serum immune balance biomarkers (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α, TGF-β and IFN-γ). Multivariable linear regression models were used to evaluate the correlation between bisphenols exposure and outcome biomarkers. After adjustment for age, BMI, menstrual cycle, and parity history, creatinine-adjusted BPA was significantly associated with increases in 8-isoprostane (β = 0.74, 95% CI = 0.07, 1.41; p = 0.031) and IFN-γ (β = 0.18, 95% CI = 0.00, 0.36; p = 0.046). No statistical correlation between BPS and biomarkers of oxidative stress or immune balance was observed when all participants were analyzed. Further analysis revealed that in the subgroup of BPS > limit of detection (0.01 ng/ml), creatinine-adjusted BPS was significantly associated with increases in IL-10 (β = 0.22, 95% CI = 0.00, 0.45; p = 0.048). Our findings suggested that BPA and BPS exposure might be related to oxidative stress and immune imbalance in URSA patients. Overall, our work might suggest potential pathogenic and aetiological associations among the bisphenols, biomarkers and URSA, which offers hypotheses for further studies.

Toxicity assessment of Fluoranthene, Benz(a)anthracene and its mixed pollution in soil: Studies at the molecular and animal levels

An increasing amount of Fluoranthene (Fla) and Benz(a)anthracene (BaA) is being produced and used, eventually entering the soil sediments. The accumulation of Fla and BaA will cause poisoning to typical enzymes (α-Amylase) and organisms (Eisenia fetida) in soil. However, the studies about exploring and comparing the different effects of Fla, BaA and their joint effect at different levels are rarely reported. In this paper, the different effects of Fla, BaA and their mixed pollutant on α-Amylase were evaluated and compared at the molecular level, and the effect of Fla-BaA to the antioxidant system of earthworm (Eisenia fetida) was investigated from the aspects of concentration and exposure time at the animal level. The results showed that Fla-BaA had the greatest influence on the skeleton structure and the microenvironment of amino acid residue of α-Amylase compared to Fla and BaA, and in the mixed pollutant system, the joint effect mode was additive mode. The inhibitory effect of Fla-BaA on the activity of α-Amylase was also stronger than that of the system alone. The assays at the animal level showed that low concentrations (below 5 mg/kg) of Fla-BaA increased the activity of GSH-Px and SOD while high concentrations inhibited their activity. The POD that was activated throughout the experiment period suggested its key role in the earthworm antioxidant system. Changes in T-AOC and MDA showed that long-term and high-dose of Fla-BaA exposure inhibited the antioxidant capacity of Eisenia fetida, causing lipid peroxidation and damage to cells.

Exposure to bisphenols and asthma morbidity among low-income urban children with asthma

BACKGROUND

Bisphenol A (BPA) has been linked with pediatric asthma development and allergic airway inflammation in animal models. Whether exposure to BPA or its structural analogs bisphenol S (BPS) and bisphenol F (BPF) is associated with asthma morbidity remains unknown.

OBJECTIVE

We examined associations between bisphenols and morbidity due to pediatric asthma.

METHODS

We quantified concentrations of BPA, BPS, and BPF in 660 urine samples from 148 predominantly low-income, African American children (aged 5-17 years) with established asthma. We used biobanked biospecimens and data on symptoms, health care utilization, and pulmonary function and inflammation that were collected every 3 months over the course of a year. We used generalized estimating equations to examine associations between concentrations or detection of urinary bisphenols and morbidity outcomes and assessed heterogeneity of associations by sex.

RESULTS

We observed consistent positive associations between BPA exposure and measures of asthma morbidity. For example, we observed increased odds of general symptom days (adjusted odds ratio [aOR] = 1.40 [95% C = 1.02-1.92]), maximal symptom days (aOR = 1.36 [95% CI = 1.00-1.83]), and emergency department visits (aOR = 2.12 [95% CI =1.28-3.51]) per 10-fold increase in BPA concentration. We also observed evidence of sexually dimorphic effects; BPA concentrations were associated with increased odds of symptom days and health care utilization only among boys. Findings regarding BPS and BPF did not consistently point to associations with asthma symptoms or health care utilization.

CONCLUSION

We found evidence to suggest that BPA exposure in a predominantly low-income, minority pediatric cohort is associated with asthma morbidity and that associations may differ by sex. Our findings support additional studies, given the high pediatric asthma burden and widespread exposure to BPA in the United States.

Mechanism investigation on Bisphenol S-induced oxidative stress and inflammation in murine RAW264.7 cells: The role of NLRP3 inflammasome, TLR4, Nrf2 and MAPK

Bisphenol S is considered as a safer alternative to bisphenol A. In the present study, we used murine macrophages to investigate the effects of BPS exposure on oxidative stress and inflammatory response as well as the underlying mechanism. Cells were exposed to BPS at various concentrations for short period of times. Results showed that 10^-8 M BPS triggered oxidative stress by increasing ROS/RNS production, increased the levels of oxidant enzyme NOX1/2, and decreased the levels of antioxidant enzymes SOD1/2, CAT and GSH-Px. 10^-8 M BPS exposure significantly induced the production of proinflammatory mediators. Activation of the NLRP3 inflammasome, TLR4, and MAPK pathways was involved in this process. Furthermore, we illustrated that NAC pretreatment diminished these effects triggered by BPS exposure. Collectively, our data suggested that BPS at a dose relevant to human serum concentration induced oxidative stress and inflammatory response in macrophages. These novel findings shed light on the concerns regarding the potential adverse effects of BPS exposure that requires further careful attention.

Bisphenol S adsorption with activated carbon prepared from corncob: optimization using response surface methodology

Activated carbon derived from raw corncob (CCAC), which prepared with steam as the activating agent, was used to adsorb bisphenol S (BPS) from aqueous solution. Characterizations of CCAC were measured by using the Brunauer-Emmett-Teller, scanning electron microscopy, and Fourier transform infrared spectroscopy. Adsorption conditions including initial BPS concentration, contact time, adsorbent dosage and pH were optimized by response surface methodology (RSM). The results show that adsorption equilibrium was well described by the Langmuir and Koble–Corrigan models. The maximum monolayer adsorption capacity of BPS was found to be 617.29 mg g−1 at 298 K. Based on the thermodynamic parameters analysis, the BPS adsorption process was turned out to be spontaneous and exothermic. The adsorption process of BPS was well described by the pseudo-second-order kinetic model. It also found that H-bonding, π–π interaction, and electrostatic interaction were the main mechanisms in the process of BPS adsorption onto the CCAC.

Biotransformation of bisphenol A analogues by the biphenyl-degrading bacterium Cupriavidusbasilensis - a structure-biotransformation relationship

Comparative analyses determined the relationship between the structure of bisphenol A (BPA) as well as of seven bisphenol analogues (bisphenol B (BPB), bisphenol C (BPC), bisphenol E (BPE), bisphenol F (BPF), bisphenol Z (BPZ), bisphenol AP (BPAP), bisphenol PH (BPPH)) and their biotransformability by the biphenyl-degrading bacterium Cupriavidus basilensis SBUG 290. All bisphenols were substrates for bacterial transformation with conversion rates ranging from 6 to 98% within 216 h and 36 different metabolites were characterized. Transformation by biphenyl-grown cells comprised four different pathways: (a) formation of ortho-hydroxylated bisphenols, hydroxylating either one or both phenols of the compounds; (b) ring fission; (c) transamination followed by acetylation or dimerization; and (d) oxidation of ring substituents, such as methyl groups and aromatic ring systems, present on the 3-position. However, the microbial attack of bisphenols by C. basilensis was limited to the phenol rings and its substituents, while substituents on the carbon bridge connecting the rings were not oxidized. All bisphenol analogues with modifications at the carbon bridge could be oxidized up to ring cleavage, while substituents at the 3-position of the phenol ring other than hydroxyl groups did not allow this reaction. Replacing one methyl group at the carbon bridge of BPA by a hydrophobic aromatic or alicyclic ring system inhibited both dimerization and transamination followed by acetylation. While most of the bisphenol analogues exhibited estrogenic activity, four biotransformation products tested were not estrogenically active.

The effects of different bisphenol derivatives on oxidative stress, DNA damage and DNA repair in RWPE-1 cells: A comparative study

Bisphenol A (BPA) is a well-known endocrine disruptor and it is widely used mainly in the plastics industry. Due to recent reports on its possible impact on health (particularly on the male reproductive system), bisphenol F (BPF) and bisphenol S (BPS) are now being used as alternatives. In this study, RWPE-1 cells were used as a model to compare cytotoxicity, oxidative stress-causing potential and genotoxicity of these chemicals. In addition, the effects of the bisphenol derivatives were assessed on DNA repair proteins. RWPE-1 cells were incubated with BPA, BPF, and BPS at concentrations of 0-600 μM for 24 h. The inhibitory concentration 20 (IC₂₀ , concentration that causes 20% of cell viability loss) values for BPA, BPF, and BPS were 45, 65, and 108 μM, respectively. These results indicated that cytotoxicity potentials were ranked as BPA > BPF > BPS. We also found alterations in superoxide dismutase, glutathione peroxidase and glutathione reductase activities, and glutathione and total antioxidant capacity in all bisphenol-exposed groups. In the standard and modified Comet assay, BPS produced significantly higher levels of DNA damage vs the control. DNA repair proteins (OGG1, Ape-1, and MyH) involved in the base excision repair pathway, as well as p53 protein levels were down-regulated in all of the bisphenol-exposed groups. We found that the BPA alternatives were also cytotoxic and genotoxic, and changed the expressions of DNA repair enzymes. Therefore, further studies are needed to assess whether they can be used safely as alternatives to BPA or not.