Exposure to New Emerging Bisphenols Among Young Children in Switzerland

Bisphenol M inhibits mouse oocyte maturation in vitro by disrupting cytoskeleton architecture and cell cycle processes

Bisphenol M (BPM), an alternative to bisphenol A (BPA), is commonly utilized in various industrial applications. However, BPM does not represent a safe substitute for BPA due to its detrimental effects on living beings. This research aimed to assess the influence of BPM exposure on the in vitro maturation of mouse oocytes. The findings revealed that BPM exposure had a notable impact on the germinal vesicle breakdown (GVBD) rate and polar body extrusion (PBE) rate throughout the meiotic progression of mouse oocytes, ultimately resulting in meiotic arrest. Investigations demonstrated that oocytes exposure to BPM led to continued activation of spindle assembly checkpoint. Further studies revealed that securin and cyclin B1 could not be degraded in BPM-exposed oocytes, and meiosis could not realize the transition from the MI to the AI stage. Mechanistically, BPM exposure resulted in abnormal spindle assembly and disrupted chromosome alignment of oocytes. Additionally, abnormal positioning of microtubule organizing center-associated proteins implied that MTOC may be dysfunctional. Furthermore, an elevation in the acetylation level of α-tubulin in oocytes was observed after BPM treatment, leading to decreased microtubule stability. In addition to its impact on microtubules, BPM exposure led to a reduction in the expression of the actin, signifying the disruption of actin assembly. Further research indicated a heightened incidence of DNA damage in oocytes following BPM exposure. Besides, BPM exposure induced alterations in histone modifications. The outcomes of this experiment demonstrate that BPM exposure impairs oocyte quality and inhibits meiotic maturation of mouse oocytes.

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.

Transcriptomic analysis reveals the effects of maternal exposure to bisphenol AF on hypothalamic development in male neonatal mice

Fragmented data suggest that bisphenol AF (BPAF), a chemical widely used in a variety of products, might have potential impacts on the hypothalamus. Here, we employed male neonatal mice following maternal exposure to explore the effects of low-dose BPAF on hypothalamic development by RNA-sequencing. We found that maternal exposure to approximately 50 µg/(kg·day) BPAF from postanal day (PND) 0 to PND 15 altered the hypothalamic transcriptome, primarily involving the pathways and genes associated with extracellular matrix (ECM) and intercellular adhesion, neuroendocrine regulation, and neurological processes. Further RNA analysis confirmed the changes in the expression levels of concerned genes. Importantly, we further revealed that low-dose BPAF posed a stimulatory impact on pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus and induced the browning of inguinal white adipose tissue. All findings indicate that developmental exposure to low-dose BPAF could interfere with hypothalamic development and thereby lead to alterations in the metabolism. Interestingly, 5000 µg/(kg·day) BPAF caused slighter, non-significant or even inverse alterations than the low dose of 50 µg/(kg·day), displaying a dose-independent effect. Further observations suggest that the the dose-independent effects of BPAF might be associated with oxidative stress and inflammatory responses caused by the high dose. Overall, our study highlights a risk of low-dose BPAF to human neuroendocrine regulation and metabolism.

Developmental effects and lipid disturbances of zebrafish embryos exposed to three newly recognized bisphenol A analogues

Bisphenol G (BPG), bisphenol M (BPM) and bisphenol TMC (BPTMC), are newly recognized analogues of bisphenol A (BPA), which have been detected in multiple environmental media. However, the understanding of their negative impacts on environmental health is limited. In this study, zebrafish embryos were exposed to BPA and the three analogues (0.1, 10, and 1000 μg/L) to identify their developmental toxic effects. According to our results, all of the three analogues induced significant developmental disorders on zebrafish embryos including inhibited yolk sac absorption, altered heart rate, and teratogenic effects. Oil Red O staining indicated lipid accumulation in the yolk sac region of zebrafish after bisphenol analogues exposure, which was consistent with the delayed yolk uptake. Untargeted lipidomic analysis indicated the abundance of triacylglycerols, ceramides and fatty acids was significantly altered by the three analogues. The combined analysis of lipidomics and transcriptomics results indicated BPG and BPM affected lipid metabolism by disrupting peroxisome proliferator-activated receptor pathway and interfering with lipid homeostasis and transport. This partly explained the morphological changes of embryos after bisphenol exposure. In conclusion, our study reveals that BPG, BPM and BPTMC possess acute and developmental toxicity toward zebrafish, and the developmental abnormalities are associated with the disturbances in lipid metabolism.

Simultaneous determination of environmental endocrine disruptors bisphenol A and 4-nitrophenol bleached from food-contacting materials using the spin-ladder compound La2Cu2O5 modified glassy carbon electrode

Environmental endocrine-disrupting chemicals, Bisphenol A (BPA) and 4-Nitrophenol (4-NP), pose significant risks to reproductive health in both animals and humans. Here, we introduce the first utilization of the 4-leg spin ladder compound La2Cu2O5 as an electrode material for electrochemical sensor. Nanostructured La2Cu2O5 was synthesized via a straightforward Sol-Gel method and thoroughly characterized using X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and powder X-ray diffraction. La2Cu2O5 nanoparticles modified glassy carbon electrode (GCE) exhibited a significant electrocatalytic activity towards the oxidation of BPA and 4-NP in phosphate buffer saline (pH 7.0). Square wave voltammetry studies revealed lowest detection limits of 3 nM for BPA and 2.6 nM for 4-NP over a wider concentration range of 0.01-500 μM. Notably, this study marks the first utilization of La2Cu2O5 for simultaneous electrochemical detection of BPA and 4-NP, demonstrating its potential in this field. Furthermore, the sensor exhibited good sensitivity, reproducibility, and selectivity towards BPA and 4-NP, even in the presence of similar potential organic and inorganic interferents. Additionally, the newly developed sensor enabled simultaneous quantification of BPA and 4-NP in real samples such as packaged milk, river water, and plastic bottles, achieving recovery rates above 95%. Importantly, our results underscore the leaching of BPA into water from thin and thick plastics at elevated temperatures (40 °C-80 °C), emphasizing the utility of the proposed sensor for rapid and simultaneous detection of BPA and 4-NP in environmental and food matrices.

Futuristic advancements in phytoremediation of endocrine disruptor Bisphenol A: A step towards sustainable pollutant degradation for rehabilitated environment

Bisphenol A (BPA) accumulates in the environment at lethal concentrations because of its high production rate and utilization. BPA, originating from industrial effluent, plastic production, and consumer products, poses serious risks to both the environment and human health. The widespread aggregation of BPA leads to endocrine disruption, reactive oxygen species-mediated DNA damage, epigenetic modifications and carcinogenicity, which can disturb the normal homeostasis of the body. The living being in a population is subjected to BPA exposure via air, water and food. Globally, urinary analysis reports have shown higher BPA concentrations in all age groups, with children being particularly susceptible due to its occurrence in items such as milk bottles. The conventional methods are costly with a low removal rate. Since there is no proper eco-friendly and cost-effective degradation of BPA reported so far. The phytoremediation, green-biotechnology based method which is a cost-effective and renewable resource can be used to sequestrate BPA. Phytoremediation is observed in numerous plant species with different mechanisms to remove harmful contaminants. Plants normally undergo several improvements in genetic and molecular levels to withstand stress and lower levels of toxicants. But such natural adaptation requires more time and also higher concentration of contaminants may disrupt the normal growth, survival and yield of the plants. Therefore, natural or synthetic amendments and genetic modifications can improve the xenobiotics removal rate by the plants. Also, constructed wetlands technique utilizes the plant's phytoremediation mechanisms to remove industrial effluents and medical residues. In this review, we have discussed the limitations and futuristic advancement strategies for degrading BPA using phytoremediation-associated mechanisms.

Assessment of baby disposable diapers application for urine collection and determination of phthalate metabolites

The baby disposable diapers were investigated as a sampling material for urine collection and validated for the evaluation of the exposure of children to xenobiotics. Phthalate metabolites detected in urine samples were chosen as proof-of-concept analytes. For the determination of phthalate metabolites in children's urine samples, high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used. Two sampling approaches were compared, namely sterile containers and baby disposable diapers. Thirty urine samples from infants and toddlers were analyzed by both methods in parallel and the results were compared. It was found that for diaper sampling, lower concentrations of the metabolites were observed, however, the general distribution for particular metabolites remains the same for both methods. For most of the metabolites high determination coefficients were obtained, namely 0.9929 for MEHHP, 0.9836 for MMP, 0.9796 for MECPP, and 0.9784 for 2-cx-MMHP. For MEOHP the determination correlation coefficient was 0.9154, while for MBP was - 0.7771 and MEHP was - 0.5228. In general, for diaper sampling an underestimation for 2-cx-MMHP and MEOHP was observed, while for MMP diaper-based approach provides overestimation. However, the proposed procedure confirms the possibility of using baby disposable diapers as a material for the collection of urine samples for biomonitoring purposes and fast screening of phthalates exposure.

Relationship of bisphenol A substitutes bisphenol F and bisphenol S with adiponectin/leptin ratio among children from the environment and development of children cohort

BACKGROUND

Bisphenol A (BPA) is known as an obesogenic endocrine disruptor. Bisphenol S (BPS) and F (BPF) are substitutes that have recently replaced BPA.

OBJECTIVES

To investigate the relationships of urinary bisphenols (BPA, BPS and BPF) with adiposity measurements (obesity, BMI z-score, and fat mass), serum adipokine levels (adiponectin and leptin), and adiponectin/leptin ratio (A/L ratio) in 6- and 8-year-old children.

METHODS

A total of 561 children who participated in the Environment and Development of Children cohort (482 and 516 children visited at age 6 and 8, respectively) at Seoul National University Children's Hospital during 2015-2019 were included. Urinary BPA levels were log-transformed. BPS levels were categorized into three groups (non-detected, lower-half, and higher-half of detected), and BPF levels were classified into two groups (non-detected and detected).

RESULTS

The urinary BPS higher-half group had a higher BMI z-score (β = 0.160, P= 0.044), higher fat mass (β = 0.104, P< 0.001), lower adiponectin concentration (β =- 0.069, P< 0.001), higher leptin concentration (β = 0.360, P< 0.001), and lower A/L ratio (β =- 0.428, P< 0.001) compared with the non-detected group. The urinary BPF-detected group had a higher fat mass (β = 0.074, P< 0.001), lower adiponectin concentration (β =- 0.069, P< 0.001), higher leptin concentration (β = 0.360, P< 0.001), and lower A/L ratio (β =- 0.428, P< 0.001) compared with the non-detected group. The BPA levels showed no consistent associations with outcomes, except for isolated associations of BPA at age 6 with a higher BMI z-score at age 6 (P= 0.016) and leptin at age 8 (P= 0.021).

CONCLUSIONS

Increased exposure to BPS and BPF is associated with higher fat mass and leptin concentration, lower serum adiponectin, and lower A/L ratio in children. These findings suggest potential adverse effects of BPA substitutes on adiposity and adipokines. No consistent association of BPA exposure with outcomes could be partly explained by the decreasing BPA levels over time.

Fate and transformation of uniformly 14C-ring-labeled bisphenol S in different aerobic soils

Bisphenol S (BPS), being structurally similar to bisphenol A (BPA), has been widely used as an alternative to BPA in industrial applications. However, in-depth studies on the environmental behavior and fate of BPS in various soils have been rarely reported. Here, 14C-labeled BPS was used to investigate its mineralization, bound residues (BRs) formation and extractable residues (ERs) in three soils for 64 days. Significant differences were found in the dissipation rates of BPS in three soils with different pH values. The dissipation of BPS followed pseudo first-order kinetics with half-lives (T1/2) of 15.2 ± 0.1 d, 27.0 ± 0.2 d, 180.4 ± 5.3 d, and 280.5 ± 3.3 d in the alkaline soil (fluvo-aquic soil, FS), the neutral soil (cinnamon soil, CS), the acidic soil (red soil, RS), and sterilized cinnamon soil (CS-S), respectively. The mineralization and BRs formation contributed the most to the dissipation of BPS in soil. BPS was persistent in acidic soil, and may pose a significant threat to plants grown in acidic soils. Additionally, soil microorganisms played a key role in BPS degradation, and the organic matter content might be a major factor that promotes the adsorption and degradation of BPS in soils. Two transformed products, P-hydroxybenzenesulfonic acid and methylated BPS were identified in soils. This study provides new insights into the fate of BPS in various soils, which will be useful for risk assessments of BPS in soil.

The Joint Effects of Bisphenols and Iodine Exposure on Thyroid during Pregnancy

The aim of this research was to study the combined effects of bisphenols and iodine exposure on the thyroid gland during pregnancy. We included 162 pregnant women from a cohort established in Shanghai. Urinary concentrations of bisphenol A, bisphenol B(BPB), bisphenol C(BPC), bisphenol F, bisphenol S, and bisphenol AF(BPAF) were examined. Bayesian kernel machine regression (BKMR) and quantile g-computation models were used. The geometric means of BPA, BPB, BPC, BPF, BPS, BPAF, and ΣBPs levels in urine were 3.03, 0.24, 2.66, 0.36, 0.26, 0.72, and 7.55 μg/g creatinine, respectively. We observed a positive trend in the cumulative effects of BPs and iodine on serum triiodothyronine (FT3) and free thyroxine (FT4), as well as a U-shaped dose-response relationship between BPs and the probability of occurrence of thyroperoxidase autoantibody positivity in women with low urinary iodine concentration. In addition, a synergistic effect on the probability of occurrence of thyroid autoantibody positivity was observed between BPF and BPB, as well as between BPC and BPAF in this study. There were adverse health effects on the thyroid after co-exposure to BPs and iodine. Even if pregnant women were exposed to lower levels of BPs, women with iodine deficiency remained vulnerable to thyroid autoimmune disease.

Simultaneous Quantification of 16 Bisphenol Analogues in Food Matrices

Exposure to bisphenol analogues can occur in several ways throughout the food production chain, with their presence at higher concentrations representing a risk to human health. This study aimed to develop effective analytical methods to simultaneously quantify BPA and fifteen bisphenol analogues (i.e., bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol S, bisphenol Z, bisphenol TMC, and tetramethyl bisphenol F) present in canned foods and beverages. Samples of foods and beverages available in the Swiss and EU markets (n = 22), including canned pineapples, ravioli, and beer, were prepared and analyzed using QuEChERS GC-MS. The quantification method was compared to a QuEChERS LC-MS/MS analysis. This allowed for the selective and efficient simultaneous quantitative analysis of bisphenol analogues. Quantities of these analogues were present in 20 of the 22 samples tested, with the most frequent analytes at higher concentrations: BPA and BPS were discovered in 78% and 48% of cases, respectively. The study demonstrates the robustness of QuEChERS GC-MS for determining low quantities of bisphenol analogues in canned foods. However, further studies are necessary to achieve full knowledge of the extent of bisphenol contamination in the food production chain and its associated toxicity.

Reconsidering "low-dose"-Impacts of oral estrogen exposure during preimplantation embryo development

Perturbations of estrogen signaling during developmental stages of high plasticity may lead to adverse effects later in life. Endocrine-disrupting chemicals (EDC) are compounds that interfere with the endocrine system by particularly mimicking the action of endogenous estrogens as functional agonists or antagonists. EDCs compose synthetic and naturally occurring compounds discharged into the environment, which may be taken up via skin contact, inhalation, orally due to contaminated food or water, or via the placenta during in utero development. Although estrogens are efficiently metabolized by the liver, the role of circulating glucuro- and/or sulpho-conjugated estrogen metabolites in the body has not been fully addressed to date. Particularly, the role of intracellular cleavage to free functional estrogens could explain the hitherto unknown mode of action of adverse effects of EDC at very low concentrations currently considered safe. We summarize and discuss findings on estrogenic EDC with a focus on early embryonic development to highlight the need for reconsidering low dose effects of EDC.

Gas chromatography-mass spectrometric determination of bisphenol residues by dispersive solid phase extraction followed by activated carbon spheres cleanup from fish feed samples

Bisphenols are known endocrine disruptors commonly utilized in food packaging and storage materials, which frequently come into touch with multiple food products packed in them. The bisphenols in fish feed and other feed materials for aquatic organisms are harmful. The consumption of such marine foods is hazardous. Hence, the feed of aquatic products needs to be verified for the presence of bisphenols. The present study was focused on developing and validating a rapid, selective, and sensitive method to quantify 11 bisphenols from the fish feed with dispersive solid-phase extraction, which was cleaned by an optimized amount of activated carbon spheres and silylated by N,O-bis(trimethylsilyl)trifluoro acetamide and analyzed by gas chromatography-mass spectrometry. The new method was rigorously tested and verified after carefully tuning various parameters affecting analyte recovery. Limit of detection (LOD) were set at 0.5-5 ng/g and limit of quantification (LOQ) at 1-10 ng/g, respectively, resulting in 95-114% recoveries. Interday and intraday precisions in terms of relative standard deviation were found to be less than 11%. The proposed approach was effectively applied in floating and sinking fish feeds. The obtained results showed that higher concentration of bisphenol A, followed by bisphenol TMC, and bisphenol M at a concentration of 256.10, 159.01, and 168.82 ng/g in floating feed and 88.04, 200.79, and 98.03 ng/g in sinking feed samples, respectively.

Recent Advances in Sources, Migration, Public Health, and Surveillance of Bisphenol A and Its Structural Analogs in Canned Foods

The occurrence of bisphenol A (BPA) and its structural analogs, known as endocrine disruptors is widely reported. Consumers could be exposed to these chemicals through canned foods, leading to health risks. Considerable advances have occurred in the pathogenic mechanism, migration law, and analytical methodologies for these compounds in canned foods. However, the confusion and controversies on sources, migration, and health impacts have plagued researchers. This review aimed to provide insights and perspectives on sources, migration, effects on human health, and surveillance of these chemicals in canned food products. Current trends in the determination of BPA and its structural analogs have focused on mass spectroscopy and electrochemical sensor techniques. Several factors, including pH, time, temperature, and volume of the headspace in canned foods, could affect the migration of the chemicals. Moreover, it is necessary to quantify the proportion of them originating from the can material used in canned product manufacturing. In addition, adverse reaction research about exposure to low doses and combined exposure with other food contaminants will be required. We strongly believe that the information presented in this paper will assist in highlighting the research needs on these chemicals in canned foods for future risk evaluations.

Bisphenol C induces developmental defects in liver and intestine through mTOR signaling in zebrafish (Danio rerio)

Bisphenol A (BPA) was widely used in the plastic products and banned in infant food containers in many countries due to the environmental and biological toxicity. As a common substitute of BPA to manufacture products, Bisphenol C (BPC) is frequently detected in human samples like infants and toddlers' urine, indicating infants and young children are at risk of BPC exposure. However, the understanding of effects of BPC exposure on early development is limited. Herein, we evaluated the early developmental toxicity of BPC and studied the underlying mechanism in a zebrafish model. We found BPC exposure leading to liver and intestinal developmental defects in zebrafish, which occurred via disruption of GPER-AKT-mTOR-RPS6 pathway. Specifically, BPC downregulated phosphorylated and total levels of mTOR, which synergistically reduced the phosphorylation of RPS6, suppressing the translation of genes essential for cell proliferation in liver and intestine such as yap1 and tcf4. Collectively, our results not only observed clear toxicity of BPC during liver and intestinal development but also demonstrated the underlying mechanism of BPC-mediated defects via disrupting the GPER-AKT-mTOR-RPS6 pathway.

Bisphenol P exposure in C57BL/6 mice caused gut microbiota dysbiosis and induced intestinal barrier disruption via LPS/TLR4/NF-κB signaling pathway

Despite being one of the most world's widely used and mass-produced compounds, bisphenol A (BPA) has a wide range of toxic effects. Bisphenol P (BPP), an alternative to BPA, has been detected in many foods. The effects of BPP dietary exposure on gut microbiota and the intestinal barrier were unclear. We designed three batches of animal experiments: The first studied mice were exposed to BPP (30 µg/kg BW/day) for nine weeks and found that they gained weight and developed dysbiosis of the gut microbiota. The second, using typical human exposure levels (L, 0.3 µg/kg BW/day BPP) and higher concentrations (M, 30 µg/kg BW/day BPP; H, 3000 µg/kg BW/day BPP), caused gut microbiota dysbiosis in mice, activated the Lipopolysaccharide (LPS) /TLR4/NF-κB signaling pathway, triggered an inflammatory response, increased intestinal permeability, and promoted bacterial translocation leading to intestinal barrier disruption. The third treatment used a combination of antibiotics and alleviated intestinal inflammation and injury. This study demonstrated the mechanism of injury and concentration effects of intestinal damage caused by BPP exposure, providing reference data for BPP use and control and yielding new insights for human disease prevention.

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.

Obesogenic effect of Bisphenol P on mice via altering the metabolic pathways

Bisphenol P (BPP), structurally similar to bisphenol A, is commonly identified in the samples of environment, food, and humans. Unfortunately, very little information is currently available on adverse effects of BPP. The obesogenic effects and underlying mechanisms of BPP on mice were investigated in this study. Compared with the control, high-resolution microcomputed tomography (micro-CT) scans displayed that the visceral fat volume of mice was significantly increased at a dose of 5 mg/kg/day after BPP exposure for 14 days, whereas the subcutaneous fat volume remained unchanged. Nontargeted metabolomic analysis revealed that BPP significantly perturbed the metabolic pathways of mouse livers, and acetyl-CoA was identified as the potential key metabolite responsible for the visceral fat induced by BPP. These findings recommend that a great deal of attention should be paid to the obesogenic properties of BPP as a result of its widely utilized and persistence in the environment.

In vitro and in silico assessment of GPER-dependent neurocytotoxicity of emerging bisphenols

To rapidly assess the toxicity of bisphenols (BPs) via the activation of G protein-coupled estrogen receptor (GPER), eight BPs action on GPER were evaluated by molecular docking and molecular dynamics (MD) simulation and then confirmed with IMR-32 cells. The target BPs significantly promoted the production of reactive oxygen species (ROS), reduced cell viability, activated the expression of apoptosis-related proteins and increased the apoptosis rate of IMR-32 cells. Intracellular Ca²⁺ level increased significantly after the treatments with bisphenol A (BPA), bisphenol E (BPE), bisphenol C (BPC) and bisphenol AP (BPAP), suggesting the activation of GPER. Moreover, the stable binding conformations between GPER and BPA, BPE, BPC and BPAP and their dynamic changes of GPER-BPs via MD simulation also suggest that these BPs may activate GPER. The interaction between bisphenol G/bisphenol P/bisphenol PH and GPER are weak, which is consistent with their low GPER activity in vitro. Notably, after the pretreatment of GPER antagonist, Ca²⁺ accumulation and ROS production induced by BPA, BPE, BPC and BPAP in IMR-32 cells were attenuated. Overall, MD simulation and in vitro results mutually verified the activation of GPER by BPs, and MD simulation can rapidly evaluate the neurocytotoxicity of BPs.

In silico profiling of endocrine-disrupting potential of bisphenol analogues and their halogenated transformation products

Due to its endocrine-disrupting properties, bisphenol A (BPA) is being phased out from plastics, thermal paper and epoxy resins, and its replacements are being introduced into the market. Bisphenols are released into the environment, where they can undergo halogenation. Unlike BPA, the endocrine-disrupting potential of BPA analogues and their halogenated transformation products has not been extensively studied. The aim of this study was to evaluate the endocrine-disrupting potential of 18 BPA analogues and their halogenated derivatives by calculating affinities for 14 human nuclear receptors utilizing the Endocrine Disruptome and VirtualToxLab™ in silico tools. Our simulations identified AR, ERs, and GR as the most favorable targets of bisphenols and their derivatives. Several BPA analogues displayed a higher predicted potential for endocrine disruption than BPA. Our models highlighted BPZ and BPPH as the most hazardous in terms of predicted endocrine activities. Halogenation, in general, was predicted to increase the binding affinity of bisphenols for AR, ERβ, MR, GR, PPARγ, and TRβ. Notably, mono- or 2,2'-di-halogenated bisphenols exhibited the highest potential for endocrine disruption. In vitro corroboration of the obtained results should be the next milestone in evaluating the safety of BPA substitutes and their halogenated transformation products.

Toxicity and Estrogenicity of Bisphenol TMC in Oryzias melastigma via In Vivo and In Silico Studies

Bisphenol 4-[1-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexyl] phenol (BPTMC), as a substitute for bisphenol A, has been detected in environments. However, the ecotoxicological data of BPTMC are extremely scarce. Here, the lethality, developmental toxicity, locomotor behavior, and estrogenic activity of BPTMC at different concentrations (0.25-2000 μg/L) in marine medaka (Oryzias melastigma) embryos were examined. In addition, the in silico binding potentials of O. melastigma estrogen receptors (omEsrs) with BPTMC were assessed by docking study. Low-concentration BPTMC exposure (including an environmentally relevant concentration, 0.25 μg/L) resulted in stimulating effects, including hatching rate, heart rate, malformation rate, and swimming velocity. However, elevated concentrations of BPTMC led to an inflammatory response, changed heart rate and swimming velocity in the embryos and larvae. In the meantime, BPTMC (including 0.25 μg/L) altered the concentrations of estrogen receptor, vitellogenin, and endogenous 17 β-estradiol as well as the transcriptional levels of estrogen-responsive genes in the embryos or/and larvae. Furthermore, elaborate tertiary structures of omEsrs were built by ab initio modeling, and BPTMC exerted potent binding potential with three omEsrs with -47.23, -49.23, and -50.30 kJ/mol for Esr1, Esr2a, and Esr2b, respectively. This work suggests that BPTMC has potent toxicity and estrogenic effects in O. melastigma.

Antagonistic mechanisms of bisphenol analogues on the estrogen receptor α in zebrafish embryos: Experimental and computational studies

Bisphenol A (BPA) can disturb the estrogen receptor α (ERα)-mediated signaling pathway, which results in endocrine-disrupting effects and reproductive toxicity. Most BPA analogues as alternatives were evidenced to generate estrogenic activity as agonists or partial agonists of ERα. Recent studies indicated that certain BPA analogues, such as bisphenol M (BPM), bisphenol P (BPP), and bisphenol FL (BPFL), exhibited strong anti-estrogenic effects comparable with the typical antagonist 4-hydroxytamoxifen. However, conflicting findings were also observed for the compounds in different in vitro assays, and whether these BPA analogues can elicit an in vivo effect on ERα at environmentally relevant concentrations remains unknown. The underlying structural basis of estrogenic/anti-estrogenic activity should be further elucidated at the atomic level. To address these issues, we combined zebrafish-based in vivo and in silico methods to assess the effects of the compounds on ERα. The results show that the expressions of ERα-mediated downstream related genes in zebrafish embryos decreased after exposed to the compounds. Further molecular dynamics simulations were used to probe the antagonistic mechanisms of the compounds on ERα. The key H-bonding interactions were identified as important ligand recognition by ERα in the analysis of binding modes and binding free energy calculations. In summary, the current study provides preliminary in vivo evidence of fish species for the anti-estrogenic activity of certain BPA analogues.

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.

Twenty bisphenol analogues in take-out polystyrene-made food containers: concentration levels, simulated migration, and risk evaluation

Bisphenol A (BPA) is mainly used to produce polycarbonate consumer products. However, the occurrence of BPA and other bisphenol analogues (BPs) in polystyrene-made plastic products, such as white foam take-out containers (WFTOCs), has not been well investigated. In this study, occurrence of 20 BPs in WFTOC samples collected from China, Canada, and Poland were investigated with a sample size of 152. Results showed that 11 out of 20 BPs have been detected at least in one WFTOC sample. Among them, BPA was the most frequently detected BP, followed by bisphenol S (BPS) and bisphenol AF, while BPF was the least detected BP. Very high concentrations of BPA and BPS were detected in WFTOCs from China (mean 2694 and 552 ng/g), compared with Canada (81 and 45 ng/g, respectively) and Poland (95 and 16 ng/g). Other BPs, such as bisphenol TMC (BPTMC; detection frequency 65%, range < LOQ - 224 ng/g), bisphenol G (17%, < LOQ - 11 ng/g), and bisphenol BP (11%, < LOQ - 1.6 ng/g), were also detected in Chinese WFTOC samples. The mean partitioning coefficients of BPA, BPS, bisphenol AP, and BPTMC between WFTOCs and tap water, 10% ethanol, 50% ethanol, corn oil, or steamed rice were 0.22 - 2.9%, 0.16 - 5.1%, 0.11 - 7.5%, 2.3 - 6.5%, or 0.19 - 0.36%, respectively. The estimated daily intake of BPA, BPS, and BPTMC through using WFTOCs were 0.50 - 547, 0.054 - 229, and < 0.66 ng/kg bw/day, respectively, for general population in China, Canada, and Poland. Overall, this study first reveals the unexpected presence of BPs in WFTOCs made of polystyrene, which contributes to the better understanding of the sources of human exposure to BPs.

Comparison of toxicokinetic properties of eleven analogues of Bisphenol A in pig after intravenous and oral administrations

Due to the restrictions of its use, Bisphenol A (BPA) has been replaced by many structurally related bisphenols (BPs) in consumer products. The endocrine disrupting potential similar to that of BPA has been described for several bisphenols, there is therefore an urgent need of toxicokinetic (TK) data for these emerging BPs in order to evaluate if their internal exposure could increase the risk of endocrine disruption. We investigated TK behaviors of eleven BPA substitutes (BPS, BPAF, BPB, BPF, BPM, BPZ, 3-3BPA, BP4-4, BPAP, BPP, and BPFL) by intravenous and oral administrations of mixtures of them to piglets and serial collection of blood over 72 h and urine over 24 h, to evaluate their disposition. Data were analyzed using nonlinear mixed-effects modeling and a comparison was made with TK predicted by the generic model HTTK package. The low urinary excretion of some BPs, in particular BPM, BPP and BPFL, is an important aspect to consider in predicting human exposure based on urine biomonitoring. Despite their structural similarities, for the same oral dose, all BPA analogues investigated showed a higher systemic exposure (area under the plasma concentration-time curve (AUC) of the unconjugated Bisphenol) than BPA (2 to 4 fold for 3-3BPA, BPAF, BPB and BPZ, 7-20 fold for BP4-4, BPAP, BPP, BPFL, BPF and BPM and 150 fold for BPS) due mainly to a considerable variation of oral bioavailability (proportion of BP administered by oral route that attains the systemic circulation unchanged). Given similarities in the digestive tract between pigs and humans, our TK data suggest that replacing BPA with some of its alternatives, particularly BPS, will likely lead to higher internal exposure to potential endocrine disruptive compounds. These findings are crucial for evaluating the risk of human exposure to these emerging BPs.

Bisphenol AF Promoted the Growth of Uterus and Activated Estrogen Signaling Related Targets in Various Tissues of Nude Mice with SK-BR-3 Xenograft Tumor

Environmental estrogens can promote the growth, migration, and invasion of breast cancer. However, few studies evaluate adverse health impacts of environmental estrogens on other organs of breast cancer patients. Therefore, the present study investigated the effects of environmental estrogen bisphenol AF (BPAF) on the main organs of female Balb/cA nude mice with SK-BR-3 xenograft tumor by detecting the organ development and gene expression of targets associated with G protein-coupled estrogen receptor 1 (GPER1)-mediated phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) and mitogen-activated protein kinase (MAPK) signaling pathways in hypothalamus, ovary, uterus, liver, and kidney. The results showed that BPAF at 20 mg/kg bw/day markedly increased the uterine weight and the uterine coefficient of nude mice compared to SK-BR-3 bearing tumor control, indicating that BPAF promoted the growth of uterus due to its estrogenic activity. Additionally, BPAF significantly up-regulated the mRNA relative expression of most targets related to nuclear estrogen receptor alpha (ERα) and GPER1-mediated signaling pathways in the hypothalamus, followed by the ovary and uterus, and the least in the liver and kidney, indicating that BPAF activated different estrogen activity related targets in different tissues. In addition, BPAF markedly up-regulated the mRNA expression of GPER1 in all tested tissues, and the molecular docking showed that BPAF could dock into GPER1. Because gene change is an early event of toxicity response, these findings suggested that BPAF might aggravate the condition of breast cancer patients through exerting its estrogenic activity via the GPER1 pathway in various organs.

Benzophenones, bisphenols and other polychlorinated/phenolic substances in Danish infants and their parents - including longitudinal assessments before and after introduction to mixed diet

BACKGROUND

Humans are widely exposed to chemicals with known or suspected endocrine disrupting effects. Among those are several benzophenones, bisphenols and other phenols commonly used in consumer products.

OBJECTIVES

To provide human biomonitoring data from young families including infants and their parents as well as longitudinal data of infants exclusively breastfed versus on mixed diet.

METHOD

Twenty-two benzophenones, bisphenols and other phenols, were measured in urine sample sets collected from more than 100 infants and their parents (the TRIO study) and in paired samples from 61 infants when exclusively breastfed and after introduction of mixed diet (the FOOD study).

RESULTS

Twelve out of 22 substances were detectable in more than half of the urine samples from infants, mothers or fathers. Large variation in excreted levels of almost all the substances were observed. The TRIO study showed that infants had comparable or even significantly higher daily urinary excretion (DUE) of benzophenone, 4-hydroxy-benzophenone, bisphenol A, bisphenol S, triclosan and 2-phenylphenol than their parents. In the FOOD study, exclusively breastfed infants had higher or similar DUE of triclosan and benzophenones compared to when they received mixed diet. Urinary levels of triclosan and the benzophenones, BP-1 and BP-3 were significantly correlated between all trio members, indicating exposure from the same sources at home. For triclosan, BP-1 and BP-3, the within family variation was lower than between families in the TRIO study. Many substances were positively correlated both within infants and parents, indicating that some families were exposed to several of these substances concurrently.

CONCLUSION

Participants in this study excreted relatively low chemical levels, however, simultaneous exposure to several chemicals with endocrine disrupting abilities is of concern due to the dose-additive effects of these substances in combination with other chemicals.

Analytical method for the biomonitoring of bisphenols and parabens by liquid chromatography coupled to tandem mass spectrometry in human hair

Bisphenols and parabens are endocrine disruptors families widely used in daily life. They are known to be linked to numerous pathologies such as reproductive disorders, obesity, breast cancer, hypertension and asthma. Biomonitoring is an essential tool for assessing population exposure to environmental pollutants. Blood and urine are the main matrices used in human biomonitoring. However, they are not suitable to evaluate long-term exposure to endocrine disruptors with a short elimination half-life such as parabens or phenols. Hair appears to be an interesting alternative matrix allowing a wide window of exposure due to an accumulation of xenobiotics during hair growth. This study presents the development and validation of a high-performance liquid chromatography coupled to tandem mass spectrometry for the simultaneous determination of bisphenol A, its chlorinated derivatives, bisphenol F, bisphenol S and parabens in human hair. An optimised sample preparation based on acidic hydrolysis followed by liquid-liquid extraction was performed, before an analysis by ultra-high performance liquid chromatography coupled to tandem mass spectrometry in multiple reaction monitoring mode. To validate the method, recognized bioanalytical guidelines were used and calibration and quality control samples were prepared in human hair samples. Linearities were over 0.996 in the whole range of concentrations. Trueness and precision were demonstrated for each target analyte with intra-day and inter-day bias values ranging from 86 % to 118 % and relative standard deviation values ranging from 0 % to 19 %. At the same time, limits of quantification were set at 0.25 ng/g for bisphenol A and parabens, 0.05 ng/g for bisphenols F and S and 0.00625 ng/g for the chlorinated derivatives of bisphenol A. This reliable method was applied to hair samples taken from hospital professionals and allowed the quantification of these endocrine disruptors in this population. Chlorinated derivatives of bisphenol A were quantified here in hair for the first time.

Development and validation of a method for determination of 17 endocrine disrupting chemicals in milk, water, blood serum and feed by UHPLC-MS/MS

The concern for human exposure to bisphenol A (BPA) has led to the introduction of other bisphenols to be used as substitutes in industrial processes. These compounds show activity similar to BPA as endocrine disruptors and could be already widespread both in the environment and in food. To monitor their possible occurrence in the food chain, an analytical method based on affinity chromatography clean-up and UHPLC coupled to tandem mass spectrometry detection was developed and in-house validated according to European law, for simultaneous determination of 17 bisphenols in milk and blood serum from bovine and buffalo, in drinking water and in feed. The analytical performance parameters of the method for these matrices were determined. The results showed satisfactory precision in terms of relative standard deviation (3.3%-21.4%), overall good trueness as mean percentage recoveries (77.0%-119.4%), with the only exception of bisphenol PH and bisphenol S in milk and BPA diglycidyl ether in serum. The high specificity and sensitivity of the method allowed us to determine the analytes at very low concentrations, that is, 0.01-1.0 ng/mL in water, 0.1-2.0 ng/mL in milk, 0.01-1.0 ng/g in blood serum and 1.0-10.0 ng/g in feed.

Improved method for the determination of endocrine-disrupting chemicals in urine of school-age children using microliquid-liquid extraction and UHPLC-MS/MS

The presence of endocrine-disrupting chemicals in our daily life is increasing every day and, by extension, human exposure and the consequences thereof. Among these substances are bisphenols and parabens. Urine is used to analyze the exposure. The determination of 12 bisphenol homologues and 6 parabens is proposed. A procedure based on a method previously developed by our research group in 2014 is improved. The extraction yield is higher, because the new protocol is 5 times more efficient. Also, a comparison between calibration with pure standards and matrix calibration, to calculate the matrix effect, was also made. A high grade of matrix effect for all analytes was observed. In terms of validation, the limits of detection (LOD) were between 0.03 and 0.3 ng mL^-1 and limits of quantification (LOQ) 0.1 to 1.0 ng mL^-1, respectively, and the recovery is higher than 86.4% and lower than 113.6%, with a RSD lower than 13.5% in all cases. A methodology for accurate and sensitive quantification of bisphenol homologues together with parabens in human urine using UHPLC-MS/MS was developed. The method was successfully applied to 30 urine samples from children.

Assessing the toxicity of bisphenol A and its six alternatives on zebrafish embryo/larvae

Bisphenol A (BPA) analogues are gradually replacing BPA in the plastics industry. Whether these alternatives are indeed safer than BPA itself, however, remains unclear. Here, we studied the toxicity of BPA and six of its alternatives-BPB, BPC, BPE, BPF, BPAF, and BPAP-using zebrafish embryos/larvae. According to their half lethal concentration (LC₅₀) values, the acute toxicity of BPA and six alternative bisphenols to zebrafish embryos, from highest to lowest, was BPAP ≈ BPAF > BPC > BPB > BPA > BPE > BPF. Under nonlethal concentrations, the tested bisphenols had different toxic effects on development in terms of reducing the hatching rate, frequency of spontaneous movements, and heart rate in the embryo, as well as inducing yolk sac edema, pericardial edema, and spinal deformation in the larvae. The estrogenic activity of BPE, BPF, and BPAF was higher than that of BPA, as shown by vtg1 expression assays. Moreover, BPA and its alternatives increased SOD activity and cell apoptosis in embryos/larvae under nonlethal concentrations. Our findings indicate that BPA alternatives may not be safer than BPA in zebrafish, and that these BPA alternatives should be applied with caution.

A critical review of presence, removal and potential impacts of endocrine disruptors bisphenol A

Bisphenol A (BPA) is a synthetic organic compound that is mainly used in the production of polymer materials polycarbonate and epoxy resin. Widespread use and irregular processing methods have led to BPA being detected globally, raising concerns about its environmental and health effects. This review outlines an overview of the presence and removal of BPA in the environment and consumer products. We also summarized the endocrine-disrupting toxicity of BPA, and the relatively less summarized neurotoxicity, cytotoxicity, reproductive toxicity, genotoxicity, and carcinogenicity. Human exposure data show that humans have been exposed to low concentrations of BPA for a long time, future research should focus on the long-term exposure and the migration of BPA from consumer products to humans and the possible health risks associated with human exposure to BPA. Exploring economical and effective methods to reduce and remove BPA from the environment is imperative. The development of safe, functional and reproducible BPA analogs and the study of its degradation products can be the focus of subsequent research.

A systematic comparison of the developmental vascular toxicity of bisphenol A and its alternatives in vivo and in vitro

Due to the potential toxicity of bisphenol A (BPA), several bisphenols (BPs), including bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF), have been gradually used as its main substitutes, and the levels of these alternatives in different environmental media have been constantly increasing. Although some previous studies have shown that bisphenol substitutes have similar or greater acute toxicity and estrogenic effects than BPA, comparative studies on the cardiovascular toxicity of BPs have not been evaluated. In this study, the developmental vascular toxicity of BPA and three predominant substitutes (BPF, BPS and BPAF) were evaluated using zebrafish embryos and human vascular endothelial cells (HUVECs). BP exposure at a sublethal concentration of 1/10 96 h median lethal concentration (96 h-LC₅₀) significantly hindered intersegmental vessel (ISV) growth, delayed common cardinal vein (CCV) remodeling and decreased subintestinal vessels (SIVs) in Tg (fli1:EGFP) zebrafish embryos. Meanwhile, the results of the endothelial tube formation assay showed that in vitro angiogenesis was inhibited by BP exposure. Mechanistically, BP exposure increased oxidative stress characterized by a significant decrease in superoxide dismutase (SOD) and catalase (CAT) activity, accompanied by increased levels of malondialdehyde (MDA) and reactive oxygen species (ROS) in both zebrafish and HUVECs. Therefore, the vascular toxicity and oxidative stress potency of the BPs were compared and evaluated, ranking as follows: BPAF > BPF > BPA > BPS. To the best of our knowledge, the present work, for the first time, systematically provides direct evidence for BPA and its alternatives on developmental vascular toxicity in vitro and in vivo. Therefore, these findings will provide insight into the rational and safe application of BPA substitutes.

New bisphenol A and bisphenol S analogs: Evaluation of their hERα agonistic and antagonistic activities using the OECD 455 in-vitro assay and molecular modeling

Bisphenol A (BPA) and bisphenol S (BPS) are agonists of hERα receptors and due to BPA regulations in many countries, several substitutes that are close analogs to BPA and BPS were developed. In the presented study, we have determined human estrogen receptor (hER)α agonist and antagonist activities with the validated OECD assay with the hERα-Hela9903 cell line for five different chemical classes of BPA and BPS analogs. This study also defined clear structure-activity relationships for agonist and antagonist activities of the 12 bisphenols on hERα, which are supported by molecular docking studies. These data show that classical analogs of BPA (e.g., bisphenols B, C, AP, E) have comparable or superior estrogenic agonist potencies compared to BPA and BPS. The most potent of these hERα agonists were even more potent than BPA, as bisphenol B and C, with IC50 values of 0.31 μM and 0.48 μM, respectively. Among these selected bisphenols, 4-4'-methylenebis (oxyethylenethio)diphenol was the most potent hERα antagonist, with an IC50 of 0.39 μM. The estrogenic agonist and antagonist potencies of these different chemical classes of BPA and BPS analogs are mutually comparable and can be used as a basis for further structure-activity relationships studies and human risk assessment.

Comparison of the materno-fetal transfer of fifteen structurally related bisphenol analogues using an ex vivo human placental perfusion model

Regulatory measures and public concerns regarding bisphenol A (BPA) have led to its replacement by a variety of alternatives in consumer products. Due to their structural similarity to BPA, these alternatives are under surveillance, however, for potential endocrine disruption. Understanding the materno-fetal transfer of these BPA-related alternatives across the placenta is therefore crucial to assess prenatal exposure risks. The objective of the study was to assess and compare the placental transfer of a set of 15 selected bisphenols (BPs) (BP 4-4, BPA, BPAF, BPAP, 3-3 BPA, BPB, BPBP, BPC, BPE, BPF, BPFL, BPM, BPP, BPS and BPZ) using the ex vivo human placental perfusion model. The UHPLC-MS/MS method for simultaneous quantification of these BPs in perfusion media, within a concentration range of 0.003-5 μM, was able to measure placenta transfer rates as low as 0.6%-4%. Despite their structural similarities, these BPs differed greatly in placental transport efficiency. The placental transfer rates of BP4-4, BPAP, BPE, BPF, 3-3BPA, BPB, BPA were similar to that of antipyrine, indicating that their main transport mechanism was passive diffusion. By contrast, the placental transfer rates of BPFL and BPS were very limited, and intermediate for BPBP, BPZ, BPC, BPM, BPP and BPAF, suggesting weak diffusional permeability and/or that their passage might involve efflux transport. These placental transfer data will be particularly useful for predicting the fetal exposure of this important class of emerging contaminants.

Molecular mechanism study of BPAF-induced proliferation of ERα-negative SKBR-3 human breast cancer cells in vitro/in vivo

Bisphenol AF (BPAF) is a known estrogen disruptor of the ERα pathway. The aim of the present study was to characterize the proliferation effects of BPAF on ERα-negative SKBR-3 breast cancer cells with mechanistic insights. BPAF at low concentrations (0.001-0.1 μM) significantly induced the proliferation of SKBR-3 cells. In a SKBR-3 tumor model in BALB/c nude mice, BPAF at 100 mg/kg body weight/day also significantly promoted the growth of SKBR-3 tumors. Low concentrations of BPAF markedly increased the expression of G protein-coupled estrogen receptor (GPER1), c-Myc, CyclinD1 and c-Fos proteins, and enhanced phosphorylation of extracellular signal-regulated kinase (Erk) and protein kinase B (Akt) in SKBR-3 cells. Further, BPAF significantly upregulated mRNA levels of related target genes in SKBR-3 cells and SKBR-3 tumor tissues in nude mice. The GPER1 inhibitor G15 and phosphatidylinositide 3-kinase (PI3K) inhibitor wortmannin (WM) inhibited phosphorylation of Erk and Akt. The specific signal inhibitors also markedly decreased the expression of target genes and weakened the cell proliferation induced by low-concentration BPAF. The findings showed that GPER1 could independently regulate BPAF-induced proliferation of SKBR-3 cells without requiring ERα. These results provide mechanistic insights into the effects of BPAF regarding ERα-negative human breast cancer development.

Concentrations of Seven Phthalate Monoesters in Infants and Toddlers Quantified in Urine Extracted from Diapers

Carrying out exposure studies on children who are not toilet trained is challenging because of the difficulty of urine sampling. In this study, we optimized a protocol for urine collection from disposable diapers for the analysis of phthalate metabolites. The exposure of Swiss children (n = 113) between 6 months and 3 years of life to seven phthalates was assessed by gas chromatography-mass spectrometry measurements. The study showed limited exposures to phthalates, with only 22% of the samples containing some of the metabolites investigated. The three most frequently detected metabolites were monoethyl phthalate, mono-cyclohexyl phthalate, and mono-benzyl phthalate. We also detected mono-n-octyl phthalate and mono(3,5,5-trimethylhexyl) phthalate, which have rarely been observed in urine from infants and toddlers; therefore, di-n-octyl phthalate and bis(3,5,5-trimethylhexyl) phthalate can be considered as potentially new emerging phthalates. This study presents an initial snapshot of the Swiss children's exposure to phthalates and provides a promising approach for further phthalate biomonitoring studies on young children using disposable diapers as urine sampling technique.

Occurrence of bisphenol A in the milk chain: A monitoring model for risk assessment at a dairy company

Bisphenol A (BPA) as a chemical hazard may enter the milk chain during primary production at the farm and, successively, during milk processing at a dairy company. To identify the potential pathways that play a role in the occurrence of BPA, a monitoring model for risk assessment based on the identification of the hazards at each stage of milk processing was investigated. Milk samples were analyzed using liquid chromatography with fluorescence detection. Quantifiable levels were detected in samples obtained from the raw milk storage tank, pasteurized milk from the storage tank, and packaged milk. The highest BPA contamination levels were detected in raw milk from the storage tank (mean 0.265 µg/L). Despite the fact that dietary exposure levels were below the temporary daily intake, BPA may have adverse effects, particularly for vulnerable population groups. New monitoring programs involving each stage of milk processing should therefore be applied.