Xenoestrogens released from lacquer coatings in food cans

Enhanced electrocatalytic removal of bisphenol a by introducing Co/N into precursor formed from phenolic resin waste

Bisphenol A (BPA) is a typical endocrine disruptor, which can be used as an industrial raw material for the synthesis of polycarbonate and epoxy resins, etc. Recently, BPA has appeared on the list of priority new pollutants for control in various countries and regions. In this study, phenolic resin waste was utilized as a multi-carbon precursor for the electrocatalytic cathode and loaded with cobalt/nitrogen (Co/N) on its surface to form qualitative two-dimensional carbon nano-flakes (Co/NC). The onset potentials, half-wave potentials, and limiting current densities of the nitrogen-doped composite carbon material Co/NC in oxygen saturated 0.5 mol H2SO4 were -0.08 V, -0.61 V, and -0.41 mA cm-2; and those of alkaline conditions were -0.65 V, -2.51 V, and -0.38 mA cm-2, and the corresponding indexes were improved compared with those of blank titanium electrodes, which indicated that the constructed nitrogen-doped composite carbon material Co/NC was superior in oxygen reduction ability. The catalysis by metallic cobalt as well as the N-hybridized active sites significantly improved the efficiency of electrocatalytic degradation of BPA. In the electro-Fenton system, the yield of hydrogen peroxide generated by cathodic reduction of oxygen was 4.012 mg L-1, which effectively promoted the activation of hydroxyl radicals. The removal rate of BPA was above 95% within 180 min. This work provides a new insight for the design and development of novel catalyst to degrade organic pollutants.

Non-monotonic effects of Bisphenol A Dimethacrylate on male mouse reproductive system and fertility leads to impaired conceptive performance

As an estrogenic agent, Bisphenol A Dimethacrylate (Bis-DMA) may incite alterations in both the reproductive tract and the neuroendocrine axis, and thus have the potential to affect the proper development, maturity and conceptive performance in animals. We investigated the consequences of 14 weeks of exposure to different concentrations of Bis-DMA on male mouse conceptive performance. Male mice were exposed to Bis-DMA (0, 0.1 mg/L, 1.0 mg/L or 10 mg/L) via drinking water, and the effects on fertility, reproductive organ weights, reproductive hormone levels, sperm counts and testicular histology were assessed. We clearly demonstrate that prolonged exposure of male mice to Bis-DMA negatively affects fertility and reproduction causing significant reductions in sperm counts, non-monotonic effects on serum LH and testosterone levels, increased seminal vesicle weights, lower number of embryonic implantations and viable fetuses, as well as, increased embryonal resorptions in females mated by Bis-DMA treated males. Furthermore, Bis-DMA caused abnormalities in testicular infrastructure with atrophic seminiferous tubules exhibiting intraepithelial vacuolization and disorganization, loss and shedding of germ cells into the lumen, and presence of apoptotic cells. Our data collectively suggest that Bis-DMA adversely affects male fertility and reproduction by interference with normal hormone signaling in the testis, inducing changes in testicular infrastructure and ultimately leading to impaired reproductive function and fertility.

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

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

Potential impacts of bisphenols on prostate cells: An overview of cytotoxicity, proliferation, oxidative stress, apoptosis, and ER-stress response activation

This study aimed to evaluate the toxic effects of Bisphenol A (BPA), Bisphenol F (BPF) and Bisphenol S (BPS) on PNT1A and PC-3 cells, focusing on their effects on endoplasmic reticulum (ER) stress and related pathways. PNT1A and PC-3 were treated with BPA, BPF and BPS at concentrations of 0.1, 1 and 10 μM for 48 h cytotoxicity, BrdU cell proliferation, ROS generation, apoptosis detection, gene expression analysis and Western blot analysis were performed. BPA induced proliferation and late apoptosis in PNT1A cells, whereas it induced both late apoptosis and early apoptosis in PC-3 cells. BPF and BPS induced late apoptosis in PC-3 cells. Increased ROS levels were observed in PNT1A cells exposed to 1-10 μM BPA. BPA, BPF and BPS increased the expression levels of ER stress-related genes in PNT1A cells. Furthermore, exposure to BPA increased the expression of ER stress-related CHOP/DDIT3 protein in PNT1A cells. These findings highlight the potential health risks associated with BPA, BPF and BPS exposure and emphasize the importance of investigating the underlying mechanisms by which these chemicals may affect human health. Further research is required to comprehensively understand the role of ER stress pathways in cellular responses to these substances.

Hormone effects of eighteen bisphenol analogues and their effects on cellular homeostasis and the typical signal pathways

Through the transfer chain of surroundings from feed to the farmed-animals and ultimately the corresponding livestock and poultry products, people are exposed to large amounts of bisphenol analogues (BPs), such as rational emissions from manufacturing plants, feed packaging bags and food packaging contact. Some BPs have been reported to show certain toxicological effects, especially, estrogen and endocrine disrupting effect. With the increasing application of BPs, the problem is becoming more and more serious. We systematically studied the hormonal effects of 18 BPs and their effects on cell homeostasis and classical signaling pathways by using classical E-SCREEN assay, fluorescent probes and western blotting. The results confirmed the estrogen-like effect of 13 BPs and 6 BPs obtained high docking scores (Scores < -9.0) for the three receptors simultaneously with the main interactions of hydrophobic, hydrogen and π-stacking of T-type bonds. BPAP regulates cells via apoptosis and steroid signaling pathway by intracellular ROS and mitochondrial followed the caspase pathway. BPE and BPS were involved in the classical NF-κB and Hippo signaling pathways. All data provides scientific basis for the safety risk assessment of endocrine disrupting and cellular homeostasis evaluation of BPs as chronic environmental pollution.

Novel decomposition of polycarbonate and effect for marine ecosystem

Analysis of pollution of the ocean plastics is presently being extensively carried out but special attention should be direct to matters. It is widely believed that plastic dose not decompose in the ocean. Certain contaminants, bisphenol-A (BPA) that serves the material for polycarbonate (PC) and epoxy resin (EPX) both of which may possibly be elute or degrade from commercial products, have often been detected in rivers, lakes and oceans. To clarify in detail the extend of this impact of this situation, purified PC (BPA free) was decomposed at temperatures range 50-230 °C. PC was seen to start decomposing at 50 °C over a 3 day period to generated 11 μg kg-1 BPA. Based on the rate constants of BPA, the activation energy was calculated 42.0 kJ mol-1. Since this value is almost same as the EPX and polystyrene (PS) of each decomposition. Based on the PC decomposition rate and the actual BPA value in the deep sea, the 280 million metric tons (MT) BPA in the world ocean was estimated. Unlike plastics, BPA shows endocrine disrupting in fish. It should thus be considered that degraded PC and EPX pose a serious threat to the marine ecosystem, directly.

New dimethacrylate monomers based on phenolphthalein and resveratrol for the application of dental materials

Potential estrogenic effects and changes in fertility are some of the health problems associated with bisphenol A (BPA) derivatives used to produce some polymers, including dental materials that contain Bis-GMA. Those issues drove this study proposing the synthesis of methacrylate resveratrol and phenolphthalein monomers that, combined with diluent monomers, generate copolymers. Their key characteristics were determined and analyzed on the chemical structure-property perspective considering monomer planarity and flexibility based on molecular dynamic simulations.

METHODS

Methacrylate resveratrol ((E)-5-(4-(methacryloyloxy)styryl)-1,3-phenylenebis(2-methylacrylate)), EMPM) and methacrylate phenolphthalein ((3-oxo-1,3-dihydroisobenzofuran-1,1-diyl)bis(4,1-phenylene)bis(2-methylacrylate)), DIFPM) were synthesized through the reaction of precursors with methacryloyl chloride. After monomers purification and spectroscopic characterization (FTIR and NMR), the following copolymers were produced: DIFPM/TEGDMA and Bis-GMA/TEGDMA, EMPM/HEMA and Bis-GMA/HEMA. Microhardness, degree of conversion, water sorption and contact angle data were statistically analyzed through one-way ANOVA and Tukey's test (p ≤ 0.05).

RESULTS

The DIFPM molecular structure's reduced flexibility proved to be an important factor to inhibit TEGDMA cyclization. In turn, the EMPM molecule's high planarity modified the spatial organization of the HEMA copolymer, altering the water diffusion and, therefore, the water sorption when compared to Bis-GMA copolymers.

CONCLUSION

The scientific findings contribute to better understand the effect of monomer chemical structures, molecular geometry, and planarity on some physicochemical properties of copolymers. Knowledge that can contribute to the design of new monomers to replace Bis-GMA.

Chemical nature of attention deficit hyperactivity disorder (ADHD) - related chemical subfamily

Endocrine disruptors have been subjected to health risk assessments. Bioassays and chemoinformatics are very useful tools to characterize their chemical nature. By performing rat hyperactivity assays, we screened some endocrine disruptors, resulting in the classification of two groups: hyperactivity-associated and hyperactivity-negative chemicals. Moreover, many epidemiological studies have reported the correlation between most of the hyperactivity-associated chemicals identified in our bioassay and patients with attention deficit hyperactivity disorder (ADHD); thus, these chemicals are emerging as a subfamily of hyperactivity-associated chemicals among endocrine disruptors. Using RDKit, chemoinformatic analyses revealed no significant differences in the distribution of molecular weight between the two groups, but significant differences in "Fraction CSP3" (number of sp³-hybridized carbons/total carbon count) and the Tanimoto coefficient were observed. Additionally, hyperactivity-associated chemicals were distinguished from two known classes of dopaminergic toxins by the Tanimoto coefficient. Machine learning methods were also applied for classification, regression analyses, and prediction. A neural network model classified the two groups. Random forest methods also showed good prediction (R = 0.9, MAE (mean absolute error) = 0.06). Using a junction tree variational autoencoder, the core structure was interpolated between phthalate and phenol in the hyperactivity-associated group. Thus, I describe the chemical nature of a new chemical family that might promote the development of ADHD in humans.

Human body burden of bisphenol A: a case study of lactating mothers in Florianopolis, Brazil

Exclusive breast milk is the diet recommended by the World Health Organization (WHO) until 6 months of age. However, breastfeeding has the potential of transferring certain toxic chemicals from the mother to the infant. Bisphenol A (BPA) is a synthetic chemical used as a monomer in polycarbonate plastics and epoxy resins. Information on BPA concentration in the breast milk of lactating mothers is very limited; thus, this study aimed to determine the concentration of BPA in the colostrum of 64 post-partum women at a university-affiliated tertiary hospital in South Brazil. The results showed that all the breast milk samples contained a high concentration of BPA with a median value of 34.18 ng/mL. Furthermore, the concentration of BPA in mothers was influenced by the consumption of foods packaged in plastic packaging, especially when the plastic is heated (p = 0.0182). The total daily intake of BPA in breastfed infants was 19.5 µg/kg/day and 28.5 µg/kg/day was recorded at the 95th percentile of body weight per day, which is higher than the maximum daily intake estimated by the European Authority of Food Safety. These data showed a high concentration of BPA in the breastmilk of the lactating mothers which might be through the use of plastic containers as food/drink packages. This is of public health importance as the high concentration of BPA in their breast milk can be an indicator of potentially serious health problems in these mothers and much more in the babies breastfed with BPA-contaminated breast milk.

Visible-light-driven photocatalytic dual-layer hollow fibre membrane ameliorates the changes of bisphenol A exposure in gastrointestinal tract

Various treatments of choice are available to overcome contamination of bisphenol A (BPA) in the environment including membrane technologies; however, the treatment still releases contaminants that threaten the human being. Therefore, the present study is conducted to investigate the degradation of BPA by recently developed visible-light-driven photocatalytic nitrogen-doping titanium dioxide (N-doped TiO₂) dual-layer hollow fibre (DLHF) membrane and its efficiency in reducing the level of BPA in contaminated water. Fabricated with suitable polymer/photocatalyst (15/7.5 wt.%) via co-extrusion spinning method, the DLHF was characterized morphologically, evaluated for BPA degradation by using submerged photocatalytic membrane reactor under visible light irradiations followed by the investigation of intermediates formed. BPA exposure effects were accessed by immunohistochemistry staining of gastrointestinal sample obtained from animal model. BPA has been successfully degraded up to 72.5% with 2 intermediate products, B1 and B2, being identified followed by total degradation of BPA. BPA exposure leads to the high-intensity IHC staining of Claudin family which indicated the disruption of small intestinal barrier (SIB) integrity. Low IHC staining intensity of Claudin family in treated BPA group demonstrated that reducing the level of BPA by N-doped TiO₂ DLHF is capable of protecting the important component of SIB. Altogether, the fabricated photocatalytic DLHF membrane is expected to have an outstanding potential in removing BPA and its health effect for household water treatment to fulfil the public focus on the safety of their household water and their need to consume clean water.

Intestinal Microecology of Mice Exposed to TiO2 Nanoparticles and Bisphenol A

Exposure to titanium dioxide nanoparticles (TiO₂ NPs) and bisphenol A (BPA) is ubiquitous, especially through dietary and other environmental pathways. In the present study, adult C57BL/6J mice were exposed to TiO₂ NPs (100 mg/kg), BPA (0, 5, and 50 mg/kg), or their binary mixtures for 13 weeks. The 16S rDNA amplification sequence analysis revealed that co-exposure to TiO₂ NPs and BPA altered the intestinal microbiota; however, this alteration was mainly caused by TiO₂ NPs. Faecal metabolomics analysis revealed that 28 metabolites and 3 metabolic pathways were altered in the co-exposed group. This study is the first to reveal the combined effects of TiO₂ NPs and BPA on the mammalian gut microbial community and metabolism dynamics, which is of great value to human health. The coexistence of TiO₂ NPs and BPA in the gut poses a potential health risk due to their interaction with the gut microbiota.

Study of eighteen typical bisphenol analogues as agonist or antagonist for androgen and glucocorticoid at sub-micromolar concentrations in vitro

Bisphenol A and its substitutions are commonly used to manufacture epoxy resins, plastic materials and different kinds of daily necessities. In this process, a large number of bisphenol analogues (BPs) are continuously released directly/indirectly into the environment. Through the chain of environment-feed-farmed-animals-livestock and poultry products, BPs present the low concentration but chronic exposure for surroundings and environment. In addition, BPs have been revealed by extensive studies as emerging endocrine disruptors, whose effects on androgens/glucocorticoids have rarely been mentioned in previous reports. The (anta-) agonist/antagonist properties of 18 classic BPs were investigated in vitro: We assessed the cytotoxicity and examined the luciferase induction values of BPs in MDA-kb2 cells, incubated single or co-incubated with dihydrotestosterone (DHT), dexamethasone, flutamide and RU486 for 24 h. From the concentration of 10^-10 to 10^-5 M, BPs had negligible cytotoxicity for MDA-kb2 cells, except for 4,4'-(9-Fluorenylidene)diphenol with the IC₅₀ 1.32 μM. All 18 BPs had the response to androgen/glucocorticoid receptors (AR/GR). BPs at nanomolar and trace concentrations are agonists, while BPs at micromolar and higher concentrations are antagonists. Molecular docking showed that BPs interact with AR/GR through hydrophobic bonds, hydrogen bonds, T-type π-stacking and water-bridge. These experimental data demonstrate the universality of the endocrine-disrupting effects of BPs and suggest the urgency of paying attention to the usages of BPs.

The effects of bisphenols on the cardiovascular system

Bisphenols, endocrine disrupting chemicals, have frequently been used for producing food packaging materials. The best-known member, bisphenol A (BPA), has been linked to impaired foetal development in animals. Possible negative effects of BPA on human health have resulted in the production of novel, so-called next-generation (NextGen) bisphenols whose effects on humans are much less explored or even missing. This review aimed to summarise and critically assess the main findings and shortages in current bisphenol research in relation to their potential impact on the cardiovascular system in real biological exposure. Because of the common presence of bisphenols in daily use products, humans are clearly exposed to these compounds. Most data are available on BPA, where total serum levels (i.e. included conjugated metabolite) can reach up to ∼430 nM, while free bisphenol levels have been reported up to ∼80 nM. Limited data are available for other bisphenols, but maximal serum levels of bisphenol S have been reported (680 nM). Such levels seem to be negligible, although in vitro studies have showed effects on ion channels, and thyroid, oestrogenic and androgenic receptors in low micromolar concentrations. Ex vivo studies suggest vasodilatory effects of bisphenols. This stays in clear contrast to the elevation of arterial blood pressure documented in vivo and in observatory cross-sectional human studies. Bisphenols are also claimed to have a negative effect on lipidic spectrum and coronary artery disease. Regardless, the reported data are generally inconsistent and unsatisfactory. Hence novel well-designed studies, testing in particular NextGen bisphenols, are needed.

Bisphenol A Interferes with Redox Balance and the Nrf2 Signaling Pathway in Xenopus tropicalis during Embryonic Development

Simple Summary

Toxicological studies of the effects of BPA on tropical clawed frog (Xenopus tropicalis) early embryos show that temporary exposure to BPA during early embryonic development can result in dramatic teratogenesis, DNA damage, and abnormal gene expression. The overall results of this study provide valuable insights for a more holistic assessment of the environmental risks related to BPA in aquatic ecosystems.

Abstract

Bisphenol A (BPA), an environmental estrogen, is widely used and largely released into the hydrosphere, thus inducing adverse effects in aquatic organisms. Here, Xenopus tropicalis was used as an animal model to investigate the oxidative effects of BPA on early embryonic development. BPA exposure prevalently caused development delay and shortened body length. Furthermore, BPA exposure significantly increased the levels of reactive oxygen species (ROS) and DNA damage in embryos. Thus, the details of BPA interference with antioxidant regulatory pathways during frog early embryonic development should be further explored.

Pubertal Bisphenol A exposure increases adult rat serum testosterone by resetting pituitary homeostasis

Bisphenol A (BPA) is widely used by manufacturers and in consumer products. Its release in the environment may affect male reproductive function. In this study, we examined the effect of low dose (0.1 mg/kg BW), short term exposure during puberty (PD21-35) on adult rat male reproduction. The results indicated that such exposure reset growth hormone (GH) and follicular stimulating hormone (FSH) homeostasis and resulted in a significantly higher level of serum testosterone without affecting serum luteinizing hormone level. QPCR and Western blot results showed that BPA significantly up-regulated selective genes/proteins in the Leydig cell steroidogenic pathway, including steroidogenic acute regulatory protein, cytochrome P450 11A1, cytochrome P450 17A, and low-density lipoprotein receptor. RNA-Seq analysis of testicular RNAs showed that BPA significantly affected the gene profiles of multiple testicular interstitial populations without affecting germ cells. Also, GO- and KEGG-analysis suggested that IGF1-related PI3K/AKT signaling was activated, which was confirmed by the increased phosphorylation of IRS1, AKT1 and CREB. The results indicated that a low-dose, short-term BPA exposure during puberty affected the adult male rat pituitary (GH and FSH) and testis (testosterone) homeostasis.

Diethylhexyl Phthalate and Bisphenol A Promote Vincristine and Tamoxifen Resistance in Vitro

Environmental estrogen active compounds are strong determinants of estrogen receptor (ER)-positive breast cancers, and increased evidence indicates their contribution to chemotherapy resistance. In the current study, the efficacy of vincristine and tamoxifen, with the presence of diethylhexyl phthalate (DEHP) and bisphenol A (BPA) and the possible involvement of estrogen and estrogen receptor-related mechanisms, was evaluated in an ER+ mammary tumor cancer cell line, MCF-7. Chemotherapeutics tamoxifen as an estrogen receptor modulator and vincristine as an antimitotic compound were selected for evaluation against the presence of common endocrine disrupters. BPA and DEHP preincubation at their proliferative concentrations for 4 h was found to decrease the cytotoxicity of vincristine. mRNA and protein expression of ESR1 and ESR 2 were decreased by vincristine, while this decrease was reversed by DEHP and BPA. Both BPA and DEHP were able to interfere with the cytotoxic activity of vincristine against MCF-7 cells through ESR1 and ESR2. This study provides in vitro toxicological evidence for vincristine resistance and its relation to estrogen active environmental pollutants in ER+ breast cancer cells.

Bisphenol-A analogs induce lower urinary tract dysfunction in male mice

Bisphenol-A (BPA), an estrogenic endocrine disrupting chemical, significantly impacts numerous diseases and abnormalities in mammals. Estrogens are known to play an important role in the biology of the prostate; however, little is known about the role of bisphenols in the etiology of prostate pathologies, including benign prostate hyperplasia (BPH) and associated lower urinary tract dysfunction (LUTD). Bisphenol-F (BPF) and bisphenol-S (BPS) are analogs often used as substitutes for BPA; they are both reported to have in vitro and in vivo estrogenic effects similar to or more potent than BPA. The objective of this study was to assess the role of these bisphenols in the development of LUTD in adult male mice. In adult mice exposed to BPA, BPS or BPF, we examined urinary tract histopathology and physiological events associated with urinary dysfunction. Mice treated with bisphenols displayed increased bladder (p < 0.005) and prostate (p < 0.0001) mass, and there was an increased number of prostatic ducts in the prostatic urethra (p < 0.05) and decreased size of the urethra lumen (p < 0.05) compared to negative controls. After two months of bisphenol exposure, mice displayed notable differences in cystometric tracings compared to controls, consistent with LUTD. Treatment of male mice with all bisphenols also induced voiding dysfunction manifested by detrusor instability and histologic changes in the prostatic urethra of male rodents, consistent with LUTD. Our results implicate BPA and its replacements in the development and progression LUTD in mice and provide insights into the development and progression of BPH/LUTS in men.

Evaluate the bisphenol A-induced redox state in cells, zebrafish and in vivo with a hydrogen peroxide turn-on fluorescent probe

Hydrogen peroxide (H₂O₂) is an important active oxygen species that plays a major role in redox balance and in physiological and pathological processes of various diseases of biological systems. As H₂O₂ is an endogenous active molecule, fluctuations in H₂O₂ content are not only affected by the state of biological system itself but also easily affected by Bisphenol A (BPA, a typical estrogenic environmental pollutant) in the external environment. Here, the near-infrared fluorescent probe Cy-NOH2 (λ_em = 750 nm) as a tool was synthesized to detect fluctuations in H₂O₂ content in cells and organisms induced by BPA. High sensitivity and excellent selectivity were found when the probe Cy-NOH2 was used to monitor endogenous H₂O₂ in vitro. In addition, the expression of H₂O₂ induced by different concentrations of BPA was able to be detected by the probe. Zebrafish and mice models were induced with different concentrations of BPA, and the H₂O₂ content showed significant increasing trends in zebrafish and livers of mice with increasing BPA concentrations. This study reveals that the probe Cy-NOH2 can be used as an effective tool to monitor the redox state in vivo under the influence of BPA, which provides a basis for clarifying the mechanisms of BPA in a variety of physiological and pathological processes.

Concentrations of bisphenols, parabens, and benzophenones in human breast milk: A systematic review and meta-analysis

BACKGROUND

Breast milk is the main source of nutrition for infants but may be responsible for their exposure to environmental chemicals, including endocrine-disrupting chemicals.

AIM

To review available evidence on the presence and concentrations of bisphenols, parabens (PBs), and benzophenones (BPs) in human milk and to explore factors related to exposure levels.

METHODS

A systematic review was carried out using Medline, Web of Science, and Scopus databases, conducting a comprehensive search of peer-reviewed original articles published during the period 2000-2020, including epidemiological and methodological studies. Inclusion criteria were met by 50 studies, which were compiled by calculating weighted detection frequencies and arithmetic mean concentrations of the chemicals. Their risk of bias was assessed using the ROBINS-I checklist.

RESULTS

Among the 50 reviewed studies, concentrations of bisphenols were assessed by 37 (74.0%), PBs by 21 (42.0%), and BPs by 10 (20.0%). Weighted detection frequencies were 63.6% for bisphenol-A (BPA), 27.9-63.4% for PBs, and 39.5% for benzophenone-3 (BP-3). Weighted mean concentrations were 1.4 ng/mL for BPA, 0.2-14.2 ng/mL for PBs, and 24.4 ng/mL for BP-3. Mean concentrations ranged among studies from 0.1 to 3.9 ng/mL for BPA, 0.1 to 1063.6 ng/mL for PBs, and 0.5 to 72.4 ng/mL for BP-3. The highest concentrations of BPA and PBs were reported in samples from Asia (versus America and Europe). Higher BPA and lower methyl-paraben concentrations were observed in samples collected after 2010. Elevated concentrations of these chemicals were associated with socio-demographic and lifestyle factors in eight studies (16.0%). Two epidemiological studies showed moderate/serious risk of bias.

CONCLUSIONS

This systematic review contributes the first overview of the widespread presence and concentrations of bisphenols, PBs, and BPs in human breast milk, revealing geographical and temporal variations. The methodological heterogeneity of published studies underscores the need for well-conducted studies to assess the magnitude of exposure to these chemicals from human milk.

The Potential Relationship Between Environmental Endocrine Disruptor Exposure and the Development of Endometriosis and Adenomyosis

Women with endometriosis, the growth of endometrial glands and stroma outside the uterus, commonly also exhibit adenomyosis, the growth of endometrial tissues within the uterine muscle. Each disease is associated with functional alterations in the eutopic endometrium frequently leading to pain, reduced fertility, and an increased risk of adverse pregnancy outcomes. Although the precise etiology of either disease is poorly understood, evidence suggests that the presence of endometriosis may be a contributing factor to the subsequent development of adenomyosis as a consequence of an altered, systemic inflammatory response. Herein, we will discuss the potential role of exposure to environmental toxicants with endocrine disrupting capabilities in the pathogenesis of both endometriosis and adenomyosis. Numerous epidemiology and experimental studies support a role for environmental endocrine disrupting chemicals (EDCs) in the development of endometriosis; however, only a few studies have examined the potential relationship between toxicant exposures and the risk of adenomyosis. Nevertheless, since women with endometriosis are also frequently found to have adenomyosis, discussion of EDC exposure and development of each of these diseases is relevant. We will discuss the potential mechanisms by which EDCs may act to promote the co-development of endometriosis and adenomyosis. Understanding the disease-promoting mechanisms of environmental toxicants related to endometriosis and adenomyosis is paramount to designing more effective treatment(s) and preventative strategies.

Autism-Related Transcription Factors Underlying the Sex-Specific Effects of Prenatal Bisphenol A Exposure on Transcriptome-Interactome Profiles in the Offspring Prefrontal Cortex

Bisphenol A (BPA) is an environmental risk factor for autism spectrum disorder (ASD). BPA exposure dysregulates ASD-related genes in the hippocampus and neurological functions of offspring. However, whether prenatal BPA exposure has an impact on genes in the prefrontal cortex, another brain region highly implicated in ASD, and through what mechanisms have not been investigated. Here, we demonstrated that prenatal BPA exposure disrupts the transcriptome-interactome profiles of the prefrontal cortex of neonatal rats. Interestingly, the list of BPA-responsive genes was significantly enriched with known ASD candidate genes, as well as genes that were dysregulated in the postmortem brain tissues of ASD cases from multiple independent studies. Moreover, several differentially expressed genes in the offspring's prefrontal cortex were the targets of ASD-related transcription factors, including AR, ESR1, and RORA. The hypergeometric distribution analysis revealed that BPA may regulate the expression of such genes through these transcription factors in a sex-dependent manner. The molecular docking analysis of BPA and ASD-related transcription factors revealed novel potential targets of BPA, including RORA, SOX5, TCF4, and YY1. Our findings indicated that prenatal BPA exposure disrupts ASD-related genes in the offspring's prefrontal cortex and may increase the risk of ASD through sex-dependent molecular mechanisms, which should be investigated further.

Chemical contaminants in canned food and can-packaged food: a review

Canning, as a preservation technique, is widely used to extend the shelf life as well as to maintain the quality of perishable foods. During the canning process, most of the microorganisms are killed, reducing their impact on food quality and safety. However, the presence of a range of undesirable chemical contaminants has been reported in canned foods and in relation to the canning process. The present review provides an overview of these chemical contaminants, including metals, polymeric contaminants and biogenic amine contaminants. They have various origins, including migration from the can materials, formation during the canning process, or contamination during steps required prior to canning (e.g. the disinfection step). Some other can-packaged foods (e.g. beverages or milk powder), which are not canned foods by definition, were also discussed in this review, as they have been frequently studied simultaneously with canned foods in terms of contamination. The occurrence of these contaminants, the analytical techniques involved, and the factors influencing the presence of these contaminants in canned food and can-packaged food are summarized and discussed.

Adsorption performance of modified agricultural waste materials for removal of emerging micro-contaminant bisphenol A: A comprehensive review

This review is an attempt to assess the adsorption performance of different green adsorbents derived from agricultural waste materials (AWMs) that were used for the elimination of bisphenol A (BPA) from aqueous matrices. Different processes including grafting, polymerization, activation and chemical treatment have been applied to functionalize and modify agricultural waste materials for the purposes of increasing their adsorptive performances toward BPA. The highest reported adsorption capacity of adsorbent from agricultural waste for the uptake of BPA is the highly microporous carbon adsorbent derived from Argan nut shell (1408 mg g^-1). Hydrogen bonding, hydrophobic and π-π interactions were reported in most studies as the main mechanisms governing the adsorption of BPA onto agricultural waste adsorbents. Equilibrium isotherm and kinetic studies for the uptake of BPA onto agricultural waste adsorbents were best described by Langmuir/Freundlich model and pseudo-second order model, respectively. Despite the effective elimination of BPA by various agricultural waste adsorbents, an appropriate selection of elution solvent is important for effective desorption of BPA from spent adsorbent. To date, ethanol, diethyl ether-methanol, methanol-acetic acid, mineral acids and sodium hydroxide are the most eluents applied for desorption of BPA molecules loaded onto AW-adsorbents. Looking toward the future, studies on the agricultural waste adsorbents based on polymers, activated carbons, nanoparticles and highly microporous carbons should be mostly considered by the researchers toward removing BPA. These future studies should be performed both in laboratory, pilot and industrial scales, and also should report the sustainable techniques for disposal of the spent AW-adsorbents after lose their adsorption performance on BPA.

Bisphenol A and male murine reproductive system: finding a link between plasticizer and compromised health

The global burden of male infertility is rising at an alarming rate affecting the lives of millions in terms of physical, emotional and societal perspectives. Among several existing endocrine disrupting chemicals, bisphenol A (BPA) has been reported by many to inflict male reproductive toxicity in different experimental models, especially in mice. This review article critically discusses the overall reproductive toxicity of BPA with a special note to its ubiquitous existence, contamination route, effects on the reproductive system and toxicity mechanisms in male mice. Disturbed redox status in germ cells and spermatozoa plays a pivotal role in BPA induced male reproductive toxicity. In this context, the involvement of mitochondria and endoplasmic reticulum is also of grave importance. Induction of caspase-dependent apoptosis is the extreme consequence that leads to deterioration of cellular parameters. Besides the oxidative cellular and histoarchitectural damages, perturbed endocrine regulation, subsequent impaired hormonal and cellular genesis program, epigenetic alterations and inflammation cumulatively reflect poor sperm quality leading to compromised reproduction. Moreover, several key issues have also been highlighted that, if addressed, will strengthen our understanding of BPA mediated male reproductive toxicity.

Web-based behavioral intervention to reduce exposure to phthalate metabolites, bisphenol A, triclosan, and parabens in mothers with young children: A randomized controlled trial

In this study, a web-based behavioral intervention was designed, which aimed to reduce exposure to phthalate metabolites, bisphenol A, triclosan, and parabens in mothers with young children. A randomized controlled design with two groups was used to verify the effects of the intervention pre- and post-test. In total, 51 mothers participated in the study, categorizing 26 and 25 in the intervention and control groups, respectively. The web-based behavioral intervention focused on changes in diet, personal care products, and health behavior and reinforced behavior through encouragement. This program included an educational video, a game for locating endocrine disruptors at home, a method for locating facilities potentially emitting endocrine disruptors, resources, and a questions and answers mode. Data were collected from May 18 to June 30, 2020. Participants allocated to the intervention group were provided access to the behavioral intervention website via a computer or smartphone. Participants allocated to the control group were sent written information about endocrine disruptors via mail. For both the intervention and control groups, questionnaire results and maternal urine samples were assessed at baseline, during the intervention, and after one month. After the intervention, the urinary concentrations of mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), bisphenol A (BPA), methylparaben (MP), ethylparaben (EP), and propylparaben (PP) were found to be significantly decreased in the intervention group. Compared with the control group, the intervention group showed significantly decreased urinary geometric mean values of MEHP, MEOHP, BPA, MP, and PP after one month compared with those during the intervention (3.8%, 16.3%, 28.4%, 9.2%, and 24.4%, respectively). Hence, the web-based behavioral intervention was effective at reducing the exposure to endocrine disruptors in mothers with young children.

Novel daidzein molecules exhibited anti-prostate cancer activity through nuclear receptor ERβ modulation, in vitro and in vivo studies

Eight novel ERβ selective daidzein analogues (NCE1-8) were synthesized and their anti-cancer activity was evaluated by in vitro and in vivo methods. Cytotoxicity study, Receptor binding studies, Luciferase assay, cMYC & Cyclin D1 expression and Caspase 3, 8 & 9 activities were measured to ascertain the anticancer activity and mechanism. Uterotropic, anti-androgenic and anti-tumour activities were performed in rodents. The results revealed that NCEs produced anti-prostate cancer activity in DU145, LNCaP and PC3 cell lines and 50% more active than genistein. NCEs was significantly down-regulated cMYC & Cyclin D1 genes and elevated caspase 3 & 9 levels and did not show any difference in uterotropic, anti-androgenic activities. The tumour weight was also reduced. The NCE 1 and 2 have shown ERβ selectivity in receptor binding studies. Daidzein with methyl substitution at R or R₁ position exhibited more ERβ selectivity and could be considered as lead molecules for anti-prostate cancer activity.

Decontamination of bisphenol A and Congo red dye from solution by using CTAB functionalised walnut shell

In this research, the eco-friendly cationic surfactant modified walnut shell (WNS-CTAB) was synthesised to enhance the uptake for bisphenol A (BPA) and Congo red (CR) from aqueous solution. The characterisation of WNS-CTAB was performed using Fourier-transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), etc. to know its physiochemical properties. The adsorption equilibrium results were best described by the Langmuir isotherm model, which confirmed the monolayer adsorption of the pollutant molecules onto the adsorbent's surface. The maximum monolayer adsorption quantity of WNS-CTAB was established to be 38.5 mg g^-1 for BPA and 104.4 mg g^-1 for CR at 303 K, respectively. Pseudo-second-order kinetic models described the adsorption kinetics of both BPA and CR. Furthermore, the intra-particle diffusion was applied to analyse the kinetic results and was established that the rate was not solely controlled by diffusion. The mechanisms associated with BPA and CR adsorption onto the WNS-CTAB may include van der Waals interaction, hydrophobic interaction, and electrostatic force. WNS-CTAB demonstrated a good reusability potential with desorption through three successive adsorption-desorption cycles performed in both experiments. Moreover, in the binary system, the adsorption capacity of BPA witnessed a 66% decrease while CR saw marginal reduction of 8.0 %. This suggests that WNS-CTAB had a higher affinity for binding to CR with higher selectivity as compared with BPA. Therefore, WNS-CTAB has exhibited huge potential to serve as a functional material for practical use in the treatment of wastewater.

Bisphenol A decreases expression of Insulin-like factor 3 and induces histopathological changes in the Testes of Rats

Bisphenol A (BPA) is a chemical agent known to have detrimental reproductive and developmental effects. The tissue-specific impacts of BPA exposures and target tissues sensitiveness to BPA are still unclear. The aim of this study was to determine the short- and long-term dose-dependent toxic effects of BPA on rat testes. Forty-eight Wistar albino male rats were divided into four groups each containing 12 rats. To induce toxicity, BPA was administered orally at three different dosages (50, 100, and 200 mg/kg) for 14 and 28 days, respectively. Testis tissues were examined using light and electron microscopy, immunohistochemistry, and biochemical methods. Serum testosterone (T) and luteinizing hormone (LH) levels were measured. Additionally, insulin-like factor 3 (INSL3) as a marker of Leydig cell function was evaluated immunohistochemically. Groups administered high doses of BPA showed severe degenerations such as testicular atrophy, spermatogenic arrest, and interstitial edema in testis. Also, a significant decrease in INSL3 immunoreactivity and serum LH and T levels was found. The results indicated that both increased exposure time and dosage of BPA caused more serious detrimental effects on testes in the rat. Decreased INSL3 and T levels was evidence of Leydig cell function impairment due to BPA.

Diet: A Source of Endocrine Disruptors

BACKGROUND

Food is indispensable for human life and determines the health and wellbeing of the consumer. As food is the source of energy for humans, it also emerges as one of the most important sources of exposure to deleterious chemicals both natural and synthetic. The food exposed chemicals cause a number of detrimental health effects in humans, with endocrine disruption being of serious concern amongst these effects. Such chemicals disrupting the health of endocrine system are known as endocrine-disrupting chemicals (EDCs). The food exposed EDCs need to be identified and classified to effectuate a cautious consumption of food by all and especially by vulnerable groups.

AIM

The aim of the present review was to discuss food as a source of exposure to common endocrine disruptors in humans. This review presents the occurrence and levels of some of the critical endocrine disruptors exposed through frequently consumed diets.

METHODS

The major source of data was PubMed, besides other relevant publications. The focus was laid on data from the last five years, however significant earlier data was also considered.

CONCLUSION

The food as a source of endocrine disruptors to humans cannot be neglected. It is highly imperative for the consumer to recognize food as a source of EDCs and make informed choices in the consumption of food items.

Roles of ERK/Akt signals in mitochondria-dependent and endoplasmic reticulum stress-triggered neuronal cell apoptosis induced by 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene, a major active metabolite of bisphenol A

Bisphenol A (BPA) is recognized as a harmful pollutant in the worldwide. Growing studies have reported that BPA can cause adverse effects and diseases in human, and link to a potential risk factor for development of neurodegenerative diseases (NDs). 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), which generated in the mammalian liver after BPA exposure, is a major active metabolite of BPA. MBP has been suggested to exert greater toxicity than BPA. However, the molecular mechanism of MBP on the neuronal cytotoxicity remains unclear. In this study, MBP exposure significantly reduced Neuro-2a cell viability and induced apoptotic events that MBP (5-15 μM) exhibited greater neuronal cytotoxicity than BPA (50-100 μM). The mitochondria-dependent apoptotic signals including the decrease in mitochondrial membrane potential (MMP) and the increase in cytosolic apoptosis-induced factor (AIF), cytochrome c release, and Bax protein expression were involved in MBP (10 μM)-induced Neuro-2a cell death. Exposure of Neuro-2a cells to MBP (10 μM) also triggered endoplasmic reticulum (ER) stress through the induction of several key molecules including glucose-regulated protein (GRP)78, C/EBP homologous protein (CHOP), X-box binding protein (XBP)-1, protein kinase R-like ER kinase (PERK), eukaryotic initiation factor 2α (eIF2α), inositol-requiring enzyme(IRE)-1, activation transcription factor(AFT)4 and ATF6, and caspase-12. Pretreatment with 4-PBA (an ER stress inhibitor) and specific siRNAs for GRP78, CHOP, and XBP-1 significantly suppressed the expression of these ER stress-related proteins and the activation of caspase-12/-3/-7 in MBP-exposed Neuro-2a cells. Furthermore, MBP (10 μM) exposure dramatically increased the activation of extracellular regulated protein (ERK)1/2 and decreased Akt phosphorylation. Pretreatment with PD98059 (an ERK1/2 inhibitor) and transfection with the overexpression of activation of Akt1 (myr-Akt1) effectively suppressed MBP-induced apoptotic and ER stress-related signals. Collectively, these results demonstrate that MBP exposure exerts neuronal cytotoxicity via the interplay of ERK activation and Akt inactivation-regulated mitochondria-dependent and ER stress-triggered apoptotic pathway, which ultimately leads to neuronal cell death.

The Impact of Estrogen and Estrogen-Like Molecules in Neurogenesis and Neurodegeneration: Beneficial or Harmful?

Estrogens and estrogen-like molecules can modify the biology of several cell types. Estrogen receptors alpha (ERα) and beta (ERβ) belong to the so-called classical family of estrogen receptors, while the G protein-coupled estrogen receptor 1 (GPER-1) represents a non-classical estrogen receptor mainly located in the plasma membrane. As estrogen receptors are ubiquitously distributed, they can modulate cell proliferation, differentiation, and survival in several tissues and organs, including the central nervous system (CNS). Estrogens can exert neuroprotective roles by acting as anti-oxidants, promoting DNA repair, inducing the expression of growth factors, and modulating cerebral blood flow. Additionally, estrogen-dependent signaling pathways are involved in regulating the balance between proliferation and differentiation of neural stem/progenitor cells (NSPCs), thus influencing neurogenic processes. Since several estrogen-based therapies are used nowadays and estrogen-like molecules, including phytoestrogens and xenoestrogens, are omnipresent in our environment, estrogen-dependent changes in cell biology and tissue homeostasis have gained attention in human health and disease. This article provides a comprehensive literature review on the current knowledge of estrogen and estrogen-like molecules and their impact on cell survival and neurodegeneration, as well as their role in NSPCs proliferation/differentiation balance and neurogenesis.

Low-dose Bisphenol A and its analogues Bisphenol F and S activate estrogen receptor ß and slightly modulate genes in human gingival keratinocytes

OBJECTIVES

This study investigated the putative activation of estrogen receptor β (ERβ) and possible effects related on gene expression in oral mucosal cells in response to the endocrine disruptor Bisphenol A (BPA) and its analogues Bisphenol F (BPF) and Bisphenol S (BPS).

METHODS

Human gingival keratinocytes (HGK) were exposed to BPA-, BPF-, and BPS-solutions in concentrations of 1.3 μM, 0.16 μM and 11.4 nM as well as 200 pM and 100 nM estradiol (E₂) for 6 h, 24 h and 4 d. Indirect immunofluorescence (IIF) was performed to detect a possible ERβ activation. Additionally, transcription of keratinocyte-relevant biomarkers was analyzed by quantitative real-time PCR (qRT-PCR). A linear mixed model and pairwise comparisons were applied for statistical analyses.

RESULTS

The tested concentrations of BPA, BPF, BPS and E₂ revealed distinct activation of ERβ at all time periods, whereat 100 nM E₂ induced the most pronounced activation. Despite the detected ERβ activation, the concentrations of BPA and its analogues induced only moderate modulation of the tested keratinocyte-relevant biomarker genes at all time periods. This also applied to 200 pM E₂, while in case of 100 nM E₂ significant changes (p < 0.05) were detected for almost all analyzed genes.

SIGNIFICANCE

Though BPA and its analogues induce activation of ERß irrespective from the chosen concentrations and incubation periods, they lack significant modulation of gene expression of keratinocyte-relevant biomarkers. Although limited to a selected number of genes, the sparse modulation of gene expression may give a hint that the substances do slightly affect transcription of gingival-keratinocyte-innate genes, since the concentrations applied to HGK were of physiological importance.

Serum levels of non-persistent environmental pollutants and risk of incident hypertension in a sub-cohort from the EPIC study

BACKGROUND

The prevalence of arterial hypertension (AHT), a well-known risk factor for cardiovascular disease, has considerably increased over last decades. Non-persistent environmental pollutants (npEPs) are a group of ubiquitous chemicals, widely used in consumer products such as food packaging and cosmetics, which have been identified as endocrine disrupting chemicals and obesogens. The aim of this study was to assess the potential associations of serum levels of three groups of npEPs with the risk of incident AHT.

METHODS

Cohort study within a sub-cohort of Granada EPIC-Spain center (n = 670). We quantified serum concentrations of three groups of npEPs, i.e., bisphenol A (BPA), four parabens: methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP), and two benzophenones: benzophenone 1 (BP1), benzophenone 3 (BP3), in samples collected at recruitment. Statistical analyses were performed by means of Cox Proportional Hazard Models.

RESULTS

Median follow-up time was 23 years. BPA and MP were found in >80% of the study population. Individuals within the 4th PP quartile (0.53-9.24 ng/ml) showed a statistically significant increased risk of AHT (HR = 1.40, p = 0.015). No associations were found for the rest of pollutants.

CONCLUSIONS

Overall, we evidenced no associations of most npEPs with AHT risk, with the exception of an increased risk in the highest PP percentiles. Considering the limitations of using one spot serum sample for exposure characterization, further research on the potential contribution of npEPs on the development of AHT risk is warranted.

Sex differences in the effects of prenatal bisphenol A exposure on autism-related genes and their relationships with the hippocampus functions

Our recent study has shown that prenatal exposure to bisphenol A (BPA) altered the expression of genes associated with autism spectrum disorder (ASD). In this study, we further investigated the effects of prenatal BPA exposure on ASD-related genes known to regulate neuronal viability, neuritogenesis, and learning/memory, and assessed these functions in the offspring of exposed pregnant rats. We found that prenatal BPA exposure increased neurite length, the number of primary neurites, and the number of neurite branches, but reduced the size of the hippocampal cell body in both sexes of the offspring. However, in utero exposure to BPA decreased the neuronal viability and the neuronal density in the hippocampus and impaired learning/memory only in the male offspring while the females were not affected. Interestingly, the expression of several ASD-related genes (e.g. Mief2, Eif3h, Cux1, and Atp8a1) in the hippocampus were dysregulated and showed a sex-specific correlation with neuronal viability, neuritogenesis, and/or learning/memory. The findings from this study suggest that prenatal BPA exposure disrupts ASD-related genes involved in neuronal viability, neuritogenesis, and learning/memory in a sex-dependent manner, and these genes may play an important role in the risk and the higher prevalence of ASD in males subjected to prenatal BPA exposure.

Endocrine Disruption of the Follicle-Stimulating Hormone Receptor Signaling During the Human Antral Follicle Growth

An increasing number of pollutants with endocrine disrupting potential are accumulating in the environment, increasing the exposure risk for humans. Several of them are known or suspected to interfere with endocrine signals, impairing reproductive functions. Follicle-stimulating hormone (FSH) is a glycoprotein playing an essential role in supporting antral follicle maturation and may be a target of disrupting chemicals (EDs) likely impacting female fertility. EDs may interfere with FSH-mediated signals at different levels, since they may modulate the mRNA or protein levels of both the hormone and its receptor (FSHR), perturb the functioning of partner membrane molecules, modify intracellular signal transduction pathways and gene expression. In vitro studies and animal models provided results helpful to understand ED modes of action and suggest that they could effectively play a role as molecules interfering with the female reproductive system. However, most of these data are potentially subjected to experimental limitations and need to be confirmed by long-term observations in human.

Bisphenol A attenuates testosterone production in Leydig cells via the inhibition of NR1D1 signaling

Bisphenol A (BPA) is an endocrine-disrupting compound that impairs testosterone synthesis in male mammals. A circadian clock gene deficiency leads to diminished fertility and even infertility in male mice. However, whether circadian clock signaling pathways mediate the suppressive effect of BPA on testosterone synthesis in Leydig cells (LCs) remains unknown. The present study aims to detect the effect of BPA on cellular circadian clock and testosterone synthesis in mouse LCs, and examine the mechanisms underlying NR1D1 signaling. BPA treatment significantly attenuated the transcription levels of Nr1d1 and steroidogenic genes (Hsd3b2 and Hsd17b3) in TM3 cells, but increased other circadian clock gene levels (Per2 and Dbp). BPA treatment also significantly downregulated NR1D1 and StAR protein expression, but upregulated BMAL1 protein expression in TM3 cells. Furthermore, there was a marked decline in testosterone production in BPA-treated TM3 cells. Intraperitoneal injection of BPA profoundly reduced NR1D1 and StAR protein levels and steroidogenic gene transcription levels (Cyp11a1, Hsd3b2, and Hsd17b3), while enhancing BMAL1 protein and other circadian clock gene (Per2 and Dbp) levels in mouse testes. Notably, serum testosterone levels were also drastically reduced in BPA-treated mice. Moreover, SR9009, an NR1D1 agonist, augmented testosterone production in TM3 cells via elevated expression of steroidogenic genes (StAR, Cyp11a1 and Hsd17b3). Conversely, Nr1d1 knockdown inhibited testosterone accumulation and attenuated steroidogenic gene expression. Moreover, treatment with SR9009 partially reversed the BPA effect on the circadian clock and testosterone production. Taken together, our study demonstrates that BPA perturbs testosterone production, at least partially, via inhibiting NR1D1 signaling in LCs.

Uptake of micropollutant-bisphenol A, methylene blue and neutral red onto a novel bagasse-β-cyclodextrin polymer by adsorption process

The presence of emerging micropollutants and dyes in water resource has raised global concern about their intense effects to aquatic environments, ecosystem and human health in general. So far, various adsorbents have been suggested for reducing the levels of bisphenol A, methylene blue and neutral red contamination in wastewaters. However, a number of these adsorbents seemed to have low adsorptive capacities and regeneration performances. In view of these, batch experiment was performed to decontaminate these pollutants from aqueous solutions using an optimized bagasse-β-cyclodextrin polymer (SB-β-CD). Characterization studies of SB-β-CD were performed using FTIR, pH point of zero charge, XRD and BET methods. Adsorption of BPA, MB and NR was favored at lower temperature (298 K) and pH of 7.0, 9.0 and 6.0, respectively. The maximum adsorption capacity of BPA, MB and NR at 298 K was 121, 963 and 685 mg g^-1, respectively. Hydrogen bonding through host-guest inclusion and electrostatic interactions could respectively attribute to uptake of BPA and MB/NR onto SB-β-CD. Adsorption kinetics of three pollutants followed pseudo-second-order model. Langmuir and Freundlich models were fitted to describe the adsorption of BPA and MB/NR, respectively. Thermodynamic parameters confirmed the occurrence of physical adsorption which is spontaneous and exothermic in nature. SB-β-CD loaded with BPA and MB/NR was certainly reused by 75% ethanol and 0.1 mol L^-1 HCl solutions, respectively. Novel SB-β-CD showed better adsorptive capacity and regeneration performances; consequently can offers practical application for removal of BPA, MB and NR from wastewaters.

Evaluation of green tea extract and epigallocatechin gallate effects on bisphenol A-induced vascular toxicity in isolated rat aorta and cytotoxicity in human umbilical vein endothelial cells

This study was designed to assess bisphenol A (BPA)-induced vascular toxicity, the effectiveness of green tea extract and epigallocatechin gallate (EGCG) against BPA toxicity, and possible underlying mechanisms. In isolated rat aorta, contractile and relaxant responses as well as malondialdehyde levels were evaluated. Cell viability and effects on the protein levels of apoptotic (bax, bcl2, and caspase-3), autophagic (LC3), and cell adhesion molecules were calculated using the MTT method and western blotting in human umbilical vein endothelial cells (HUVECs). BPA increased aorta MDA levels (p < .0001) and decreased vascular responses to KCl [20 and 40 mM (p < .0001), 80 mM (p < .001)], phenylephrine [10^-8 , 10^-6 , and 10^-5 M (p < .001), 10^-7 and 10^-4 M (p < .0001)], and acetylcholine [10^-6 M (p < .01), 10^-5 and 10^-4 M (p < .0001)]. In HUVECs, BPA enhanced the levels of LC3A/B, bax/bcl2 ratio, cleaved caspase-3, and vascular cell adhesion molecule-1. Green tea extract, EGCG, and vitamin E co-treatment with BPA diminished the toxic effects of BPA. These findings provide evidence that green tea extract and EGCG possess beneficial effects in preventing BPA-induced vascular toxicity through increasing the antioxidant activities and the regulation of signaling pathways.

Insights into the interactions of bisphenol and phthalate compounds with unamended and carnitine-amended montmorillonite clays

Montmorillonite clays could be promising sorbents to mitigate toxic compound exposures. Bisphenols A (BPA) and S (BPS) as well as phthalates, dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP), are ubiquitous environmental contaminants linked to adverse health effects. Here, we combined computational and experimental methods to investigate the ability of montmorillonite clays to sorb these compounds. Molecular dynamics simulations predicted that parent, unamended, clay has higher binding propensity for BPA and BPS than for DBP and DEHP; carnitine-amended clay improved BPA and BPS binding, through carnitine simultaneously anchoring to the clay through its quaternary ammonium cation and forming hydrogen bonds with BPA and BPS. Experimental isothermal analysis confirmed that carnitine-amended clay has enhanced BPA binding capacity, affinity and enthalpy. Our studies demonstrate how computational and experimental methods, combined, can characterize clay binding and sorption of toxic compounds, paving the way for future investigation of clays to reduce BPA and BPS exposure.

Environmental Impact on Male (In)Fertility via Epigenetic Route

In the last 40 years, male reproductive health-which is very sensitive to both environmental exposure and metabolic status-has deteriorated and the poor sperm quality observed has been suggested to affect offspring development and its health in adult life. In this scenario, evidence now suggests that epigenetics shapes endocrine functions, linking genetics and environment. During fertilization, spermatozoa share with the oocyte their epigenome, along with their haploid genome, in order to orchestrate embryo development. The epigenetic signature of spermatozoa is the result of a dynamic modulation of the epigenetic marks occurring, firstly, in the testis-during germ cell progression-then, along the epididymis, where spermatozoa still receive molecules, conveyed by epididymosomes. Paternal lifestyle, including nutrition and exposure to hazardous substances, alters the phenotype of the next generations, through the remodeling of a sperm epigenetic blueprint that dynamically reacts to a wide range of environmental and lifestyle stressors. With that in mind, this review will summarize and discuss insights into germline epigenetic plasticity caused by environmental stimuli and diet and how spermatozoa may be carriers of induced epimutations across generations through a mechanism known as paternal transgenerational epigenetic inheritance.

A study on the effect of phthalate esters and their metabolites on idiopathic infertile males

Phthalate plasticisers in medical, cosmetic and consumer products might pose serious health implications in humans including infertility. We sought to investigate the correlation, if any, between the phthalates and their metabolites and sperm quality parameters, and male infertility. Phthalate esters (15) and their metabolites (5) were estimated in the blood serum and urine samples from the age-matched 152 infertile and 75 fertile males using gas chromatography (GC) and high-performance liquid chromatography (HPLC). Finally, the data were analysed to correlate phthalate exposure and semen quality parameters in the infertility group. The estimated levels of DEHP, DBP, DIBP, BEHIP, BPBG, DPP, DIOP, DIHP, DMP, DINP, BIOP, DMOP and DICHP were significantly higher in the infertile males compared to the fertile males (p < .05 or p < .01). However, these were not found to be associated with the semen quality parameters (sperm count, motility and sperm morphology). Similarly, HPLC data revealed that the associations between semen parameters (sperm count, sperm motility and sperm morphology) and phthalate metabolite (MEHP and MBP) concentrations in urine samples from the infertile males were mostly unremarkable or statistically nonsignificant. Conclusively, environmental exposure to phthalates and their impacts on male infertility were statistically insignificant in our study groups.

Bisphenol A and Male Fertility: Myths and Realities

Bisphenol A (BPA) represents the main chemical monomer of epoxy resins and polycarbonate plastics. The environmental presence of BPA is widespread, and it can easily be absorbed by the human body through dietary and transdermal routes, so that more than 90% of the population in western countries display detectable BPA levels in the urine. As BPA is qualified as an endocrine disruptor, growing concern is rising for possible harmful effects on human health. This review critically discusses the available literature dealing with the possible impact of BPA on male fertility. In rodent models, the in vivo exposure to BPA negatively interfered with the regulation of spermatogenesis throughout the hypothalamic-pituitary-gonadal axis. Furthermore, in in vitro studies, BPA promoted mitochondrial dysfunction and oxidative/apoptotic damages in spermatozoa from different species, including humans. To date, the claimed clinical adverse effects on male fertility are largely based on the results from studies assessing the relationship between urinary BPA concentration and conventional semen parameters. These studies, however, produced controversial evidence due to heterogeneity in the extent of BPA exposure, type of population, and enrollment setting. Moreover, the cause-effect relationship cannot be established due to the cross-sectional design of the studies as well as the large spontaneous between- and within-subject variability of semen parameters. The best evidence of an adverse effect of BPA on male fertility would be provided by prospective studies on clinically relevant endpoints, including natural or medically assisted pregnancies among men either with different exposure degrees (occupational/environmental) or with different clinical conditions (fertile/subfertile).

Bisphenol A: an emerging threat to female fertility

Bisphenol-A (BPA) has been reported to be associated to female infertility. Indeed, BPA has been found to be more frequently detected in infertile women thus leading to hypothesize a possible effect of BPA on natural conception and spontaneous fecundity. In addition, in procedures of medically assisted reproduction BPA exposure has been found to be negatively associated with peak serum estradiol levels during gonadotropin stimulation, number of retrieved oocytes, number of normally fertilized oocytes and implantation. BPA deleterious effects are more critical during perinatal exposure, causing dysregulation of hypothalamic-pituitary-ovarian axis in pups and adults, with a precocious maturation of the axis through a damage of GnRH pulsatility, gonadotropin signaling and sex steroid hormone production. Further, BPA exposure during early lifestage may have a transgenerational effect predisposing the subsequent generations to the risk of developing BPA related disease. Experimental studies suggested that prenatal, perinatal and postnatal exposure to BPA can impair several steps of ovarian development, induce ovarian morphology rearrangement and impair ovarian function, particularly folliculogenesis, as well as can impair uterus morphology and function, in female adult animal and offspring. Finally, studies carried out in animal models have been reported the occurrence of endometriosis-like lesions after BPA exposure. Moreover, BPA exposure has been described to encourage the genesis of PCOS-like abnormalities through the impairment of the secretion of sex hormones affecting ovarian morphology and functions, particularly folliculogenesis. The current manuscript summarizes the evidence regarding the association between BPA exposure and female infertility, reviewing both clinical and preclinical studies.

Metabonomics reveals bisphenol A affects fatty acid and glucose metabolism through activation of LXR in the liver of male mice

Bisphenol-A (BPA) is a representative environmental endocrine disrupting chemical that is widely used in the production of polycarbonate plastics and epoxy resins. Many studies have confirmed BPA to be closely associated with metabolic diseases, reproductive system diseases, and sex hormone-dependent cancers. In this study, we aimed to systematically elucidate the molecular action of BPA on liver fatty acid and glucose metabolism and the reasons for BPA-induced hypoglycemia through a metabonomics approach. C57BL/6 mice were orally treated with BPA (1, 10, 50, 250 μg/kg) for 35 days and the liver metabonomics and histopathology, molecular docking, mRNA expression levels and activities of enzymes were analyzed. Based on the high-resolution mass spectrometry (MS) for metabonomics and on various software and bioinformatic analysis methods, we found that BPA could affect fatty acid and glucose metabolism, block the TCA cycle, and BPA also regulated the nuclear receptor LXR caused hypoglycemia, thereby affecting the normal metabolic functions of the liver.

Experimental Approaches for Characterizing the Endocrine-Disrupting Effects of Environmental Chemicals in Fish

Increasing industrial and agricultural activities have led to a disturbing increase of pollutant discharges into the environment. Most of these pollutants can induce short-term, sustained or delayed impacts on developmental, physiological, and behavioral processes that are often regulated by the endocrine system in vertebrates, including fish, thus they are termed endocrine-disrupting chemicals (EDCs). Physiological impacts resulting from the exposure of these vertebrates to EDCs include abnormalities in growth and reproductive development, as many of the prevalent chemicals are capable of binding the receptors to sex steroid hormones. The approaches employed to investigate the action and impact of EDCs is largely dependent on the specific life history and habitat of each species, and the type of chemical that organisms are exposed to. Aquatic vertebrates, such as fish, are among the first organisms to be affected by waterborne EDCs, an attribute that has justified their wide-spread use as sentinel species. Many fish species are exposed to these chemicals in the wild, for either short or prolonged periods as larvae, adults, or both, thus, studies are typically designed to focus on either acute or chronic exposure at distinct developmental stages. The aim of this review is to provide an overview of the approaches and experimental methods commonly used to characterize the effects of some of the environmentally prevalent and emerging EDCs, including 17 α-ethinylestradiol, nonylphenol, BPA, phthalates, and arsenic; and the pervasive and potential carriers of EDCs, microplastics, on reproduction and growth. In vivo and in vitro studies are designed and employed to elucidate the direct effects of EDCs at the organismal and cellular levels, respectively. In silico approaches, on the other hand, comprise computational methods that have been more recently applied with the potential to replace extensive in vitro screening of EDCs. These approaches are discussed in light of model species, age and duration of EDC exposure.