Bisphenol A and Ovarian Reserve among Infertile Women with Polycystic Ovarian Syndrome

Toxicological Impact of Bisphenol A on Females' Reproductive System: Review Based on Experimental and Epidemiological Studies

The study encompassing research papers documented in the last two decades pertaining to the possible influence of bisphenol A (BPA) on the fertility of females are appraised with emphasis on the influence of BPA in reproductive organs (uterus and ovaries) and pregnancy outcomes including discussion on the reproductive process (implantation, estrous cycle, hormone secretion); outcomes reveal a connection amongst BPA and female infertility. Ovary, uterus, and its shape as well as function can alter a person's ability to become pregnant by influencing the hypothalamus-pituitary axis in the ovarian model. Additionally, implantation and the estrous cycle may be affected by BPA. However, more research is warranted to comprehend the underlying action mechanisms and to promptly identify any imminent reproductive harm.

Bisphenol A and polycystic ovary syndrome in human: A systematic review

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrine disorder characterized by anovulation, hyperandrogenism, and polycystic ovarian morphology. Its etiology is uncertain and one of the hypotheses is that environmental factors, such as the bisphenol A (BPA) endocrine disruptor, may be involved.

OBJECTIVE

To investigate the association between exposure to BPA and PCOS.

SEARCH STRATEGY

Research was conducted focusing on studies published in English, Portuguese, and Spanish from January 2001 to March 2023 and available in Embase, Medline/PubMed, Rima, Lilacs, Scielo, Google academic, and SCI databases.

SELECTION CRITERIA

Studies in humans that evaluated the association between exposure to BPA and a diagnosis of PCOS.

DATA COLLECTION AND ANALYSIS

Following PRISMA guidelines, study characteristics and relevant data were extracted.

MAIN RESULTS

Selection of 15 case-control and 7 cross-sectional studies with a total of 1682 PCOS patients. The studies were carried out in China, Poland, Turkey, Japan, Greece, Italy, the USA, Iran, Iraq, Egypt, India, Czechia, and Slovakia. A positive relationship between exposure to BPA and PCOS was described in19 studies (1391 [82.70%] of the PCOS patients). The fluids used in the studies were serum, urine, plasma, and follicular fluid. BPA was measured by ELISA and by chromatography (HPLC, HPLC-MS/MS, GC-MS, and GC-MS/MS). Diagnosis of PCOS used Rotterdam criteria in 15, NIH 1999 in 3, AE&PCOS Society in 2, similar to the Rotterdam criteria in 1, and criteria not informed in 1. Androgens were measured in 16 studies; in 12, hyperandrogenism was positively associated with BPA. BPA level was related to body mass index (BMI) in studies. In 15 studies independently of BMI, women with PCOS had higher BPA levels. Carbohydrate metabolism disorders were evaluated in 12 studies and in 6 a positive correlation was found with BPA levels. Lipid profile was evaluated in seven studies and in only one the correlation between lipid profile and BPA levels was present.

CONCLUSIONS

Exposure to BPA is positively associated with PCOS, mainly with the hyperandrogenism.

Exposure to bisphenol A affects transcriptome-wide N6-methyladenine methylation in ovarian granulosa cells

Bisphenol A (BPA) is an endocrine disruptor of potential reproductive toxicities. Increasingly research elucidated that BPA exposure to the environment would change the epigenetic modifications of transcriptome, but the mechanism by which BPA affects m6A methylation in interfering with female reproductive health remains uncertain. Therefore, this study preliminarily proposed and tested the hypothesis that BPA exposure alters the m6A modification level in transcripts in female ovarian granulosa cells. After BPA was exposed to granulosa cells for 24 h, RNA methylation related regulatory genes (such as METTL3, METTL14, ALKBH5, FTO) and the global m6A levels showed significant differences. Next, we applied MERIP-seq analysis to obtain information on the genome-wide m6A modification changes and identified 1595 differentially methylated mRNA transcripts, and 50 differentially methylated lncRNA transcripts. Further joint analysis of gene common expression showed that 33 genes were hypermethylated and up-regulated, 71 were hypermethylated and down-regulated, 49 were hypomethylated and up-regulated, and 20 were hypomethylated and down-regulated. Enriched Gene Ontology (GO) and biological pathway analysis revealed that these unique genes were mainly enriched in lipid metabolism, cell proliferation, and apoptosis related pathways. Six of these genes (mRNAs IMPA1, MCOLN1, DCTN3, BRCA2, and lncRNAs MALAT1, XIST) were validated using RT-qPCR and IGV software. Through comprehensive analysis of epitranscriptome and protein-protein interaction (PPI) data, lncRNAs MALAT1 and XIST are expected to serve as new markers for BPA interfering with the female reproductive system. In brief, these data show a novel and necessary connection between the damage of BPA exposure on female ovarian granulosa cells and RNA methylation modification.

Rapamycin protects Sertoli cells against BPA-induced autophagy disorders

Bisphenol A (BPA) is a well-known environmental contaminant that can negatively impact reproductive function. Disruption of autophagy is implicated in BPA-induced cell injury, the specific molecular mechanisms through which BPA affects autophagy in Sertoli cells are still unknown. In the present study, TM4 cells were exposed to various doses of BPA (10, 100, and 200 μM), and the results indicated that BPA exposure led to the accumulation of autophagosomes, this change was accompanied by increased expression of p-mTOR and decreased expression of Atg12, a protein involved in regulating autophagy initiation. Additionally, BPA exposure upregulated the expression levels of p62, a protein involved in autophagic degradation. The inhibition of autophagy initiation and autophagic degradation contributes to the accumulation of autophagosomes. Further studies showed that BPA exposure didn't affect the expression of the lysosome protein LAMP1; however, decreased cytoplasmic retention of acridine orange in TM4 cells may explain the disruption of autophagy. The role of rapamycin and chloroquine (CQ), an autophagy inhibitor that impairs lysosomal degradation also confirmed the effect of BPA on autophagy regulation. Specifically, rapamycin can protect Sertoli cells against BPA-induced cell injury by promoting autophagy. These findings contribute to our understanding of the mechanisms underlying reproductive toxicity caused by BPA.

Endocrine disruptors: Unravelling the link between chemical exposure and Women's reproductive health

An Endocrine Disrupting Chemical (EDC) is any compound that disrupts the function of the endocrine system in humans and is ubiquitous in the environment either as a result of natural events or through anthropogenic activities. Bisphenol A, phthalates, parabens, pesticides, triclosan, polychlorinated biphenyls, and heavy metals, which are frequently found in the pharmaceutical, cosmetic, and packaging sectors, are some of the major sources of EDC pollutants. EDCs have been identified to have a deteriorating effect on the female reproductive system, as evidenced by the increasing number of reproductive disorders such as endometriosis, uterine fibroids, polycystic ovary syndrome, premature ovarian failure, menstrual irregularity, menarche, and infertility. Studying EDCs in relation to women's health is essential for understanding the complex interactions between environmental factors and health outcomes. It enables the development of strategies to mitigate risks, protect reproductive and overall health, and inform public policy decisions to safeguard women's well-being. Healthcare professionals must know the possible dangers of EDC exposure and ask about environmental exposures while evaluating patients. This may result in more precise diagnosis and personalized treatment regimens. This review summarises the existing understanding of prevalent EDCs that impact women's health and involvement in female reproductive dysfunction and underscores the need for more research. Further insights on potential mechanisms of action of EDCs on female has been emphasized in the article. We also discuss the role of nutritional intervention in reducing the effect of EDCs on women's reproductive health. EDC pollution can be further reduced by adhering to strict regulations prohibiting the release of estrogenic substances into the environment.

The influence of environmental factors on premature ovarian insufficiency and ovarian aging

Premature ovarian insufficiency and ovarian aging are complex conditions that affect women's reproductive health and overall well-being. They are both characterized by hypergonadotropic hypogonadism and infertility, and together affect about 1 in 100 women by the age of 40. This review explores the influence of environmental factors on the development and progression of premature ovarian insufficiency and ovarian aging. When referring to environmental factors, we include a wide range of external agents and conditions, including chemicals, socioeconomic factors and lifestyle choices. Through a review of the literature, we attempt to highlight the link between environmental factors and ovarian health. We examine the impact of endocrine-disrupting chemicals, such as bisphenol A and phthalates, on ovarian function and investigate the mechanisms by which these chemicals can disrupt hormone signaling pathways, leading to alterations in ovarian reserve, oocyte quality, and folliculogenesis. Moreover, we explore lifestyle factors like obesity, stress, smoking and alcohol in relation to their effects on ovarian aging. Epigenetic changes may play a crucial role in the prevalence of premature ovarian insufficiency. Understanding the impact of environmental factors on premature ovarian insufficiency and ovarian aging is very important in public and clinical health contexts. By identifying risk factors, healthcare providers can develop targeted and strategic prevention and intervention plans. Furthermore, this knowledge can promote reproductive health and minimize exposure to harmful environmental agents.

Invisible Hand behind Female Reproductive Disorders: Bisphenols, Recent Evidence and Future Perspectives

Reproductive disorders are considered a global health problem influenced by physiological, genetic, environmental, and lifestyle factors. The increased exposure to bisphenols, a chemical used in large quantities for the production of polycarbonate plastics, has raised concerns regarding health risks in humans, particularly their endocrine-disrupting effects on female reproductive health. To provide a basis for future research on environmental interference and reproductive health, we reviewed relevant studies on the exposure patterns and levels of bisphenols in environmental matrices and humans (including susceptible populations such as pregnant women and children). In addition, we focused on in vivo, in vitro, and epidemiological studies evaluating the effects of bisphenols on the female reproductive system (the uterus, ovaries, fallopian tubes, and vagina). The results indicate that bisphenols cause structural and functional damage to the female reproductive system by interfering with hormones; activating receptors; inducing oxidative stress, DNA damage, and carcinogenesis; and triggering epigenetic changes, with the damaging effects being intergenerational. Epidemiological studies support the association between bisphenols and diseases such as cancer of the female reproductive system, reproductive dysfunction, and miscarriage, which may negatively affect the establishment and maintenance of pregnancy. Altogether, this review provides a reference for assessing the adverse effects of bisphenols on female reproductive health.

Does bisphenol A (BPA) participates in the pathogenesis of Polycystic Ovary Syndrome (PCOS)?

PCOS is an endocrine disorder characterized by chronic anovulation, hyperandrogenism, and polycystic ovaries. Its etiology is uncertain. It is debated whether BPA would be a component of the environmental factor in the etiology of PCOS. Contamination by BPA can occur from food packaging (exposure during the diet) and through skin absorption and/or inhalation. It can be transferred to the fetus via the placenta or to the infant via breast milk, and it can be found in follicular fluid, fetal serum, and amniotic fluid. The phenolic structure of BPA allows it to interact with Estrogen Receptors (ERs) through genomic signaling, in which BPA binds to nuclear ERα or Erβ, or through nongenomic signaling by binding to membrane ERs, prompting a rapid and intense response. With daily and constant exposure, BPA's tendency to bioaccumulate and its ability to activate nongenomic signaling pathways can alter women's metabolic and reproductive function, leading to hyperandrogenism, insulin resistance, obesity, atherogenic dyslipidemia, chronic inflammatory state, and anovulation and favoring PCOS. The harmful changes caused by BPA can be passed on to future generations without the need for additional exposure because of epigenetic modifications. Not only high BPA levels can produce harmful effects, but at low levels, BPA may be harmful when exposure occurs during the most vulnerable periods, such as the fetal and neonatal periods, as well as during the prepubertal age causing an early accumulation of BPA in the body. Learning how BPA participates in the pathogenesis of PCOS poses a challenge and further studies should be conducted.

Endocrine disrupting chemicals and male fertility: from physiological to molecular effects

The deleterious effects of chemical or non-chemical endocrine disruptors (EDs) on male fertility potential is well documented but still not fully elucidated. For example, the detection of industrial chemicals' metabolites in seminal plasma and follicular fluid can affect efficiency of the gametogenesis, the maturation and competency of gametes and has guided scientists to hypothesize that endocrine disrupting chemicals (EDCs) may disrupt hormonal homoeostasis by leading to a wide range of hormonal control impairments. The effects of EDCs exposure on reproductive health are highly dependent on factors including the type of EDCs, the duration of exposure, individual susceptibility, and the presence of other co-factors. Research and scientists continue to study these complex interactions. The aim of this review is to summarize the literature to better understand the potential reproductive health risks of EDCs in France.

The PCOS-NAFLD Multidisease Phenotype Occurred in Medaka Fish Four Generations after the Removal of Bisphenol A Exposure

As a heterogeneous reproductive disorder, polycystic ovary syndrome (PCOS) can be caused by genetic, diet, and environmental factors. Bisphenol A (BPA) can induce PCOS and nonalcoholic fatty liver disease (NAFLD) due to direct exposure; however, whether these phenotypes persist in future unexposed generations is not currently understood. In a previous study, we observed that transgenerational NAFLD persisted in female medaka for five generations (F4) after exposure to an environmentally relevant concentration (10 μg/L) of BPA. Here, we demonstrate PCOS in the same F4 generation female medaka that developed NAFLD. The ovaries contained immature follicles, restricted follicular progression, and degenerated follicles, which are characteristics of PCOS. Untargeted metabolomic analysis revealed 17 biomarkers in the ovary of BPA lineage fish, whereas transcriptomic analysis revealed 292 genes abnormally expressed, which were similar to human patients with PCOS. Metabolomic-transcriptomic joint pathway analysis revealed activation of the cancerous pathway, arginine-proline metabolism, insulin signaling, AMPK, and HOTAIR regulatory pathways, as well as upstream regulators esr1 and tgf signaling in the ovary. The present results suggest that ancestral BPA exposure can lead to PCOS phenotypes in the subsequent unexposed generations and warrant further investigations into potential health risks in future generations caused by initial exposure to EDCs.

Serum Organophosphate Flame retardants and plasticizers in Chinese females of childbearing age: Association with serum reproductive and thyroid hormones

Organophosphate flame retardants (OPFRs) are extensively used as flame retardants and plasticizers, but their endocrine disrupting potentials have raised concerns. However, the impacts of OPFR exposures on reproductive and thyroid hormones in females remains unclear. In this study, serum concentrations of OPFRs were investigated, and levels of reproductive and thyroid hormones, including follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, anti-Müllerian hormone, prolactin (PRL), testosterone (T), and thyroid stimulating hormone, were analyzed in childbearing-age females undergoing in-vitro fertilization treatment from Tianjin, a coastal city in China (n = 319). Tris (2-chloroethyl) phosphate (TCEP) was the predominant OPFR, with a median concentration of 0.33 ng/mL and a detection frequency of 96.6%. In the whole population, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP) were positively associated with T (p < 0.05), while triethyl phosphate (TEP) was negatively associated with LH (p < 0.05) and LH/FSH (p < 0.01). Particularly, TCIPP was negatively associated with PRL in the younger subgroup (age≤30, p < 0.05). Moreover, TCIPP was negatively associated with diagnostic antral follicle counting (AFC) in the mediation analysis by a dominating direct effect (p < 0.01). In conclusion, serum levels of OPFRs were significantly associated with reproductive and thyroid hormone levels and a risk of decreased ovarian reserve in childbearing-age females, with age and body mass index being significant influencing factors.

Urinary bisphenol A and S are associated with diminished ovarian reserve in women from an infertility clinic in Northern China

Bisphenol A (BPA) has been demonstrated to cause ovarian toxicity including disruption of steroidogenesis and inhibition of follicle growth. Still, human evidence is lacking on its analogs such as bisphenol F (BPF) and bisphenol S (BPS). In this study, we aimed to investigate the associations between exposure to BPA, BPF, and BPS with ovarian reserve in women of childbearing age. We recruited 111 women from an infertility clinic in Shenyang, North China between September 2020 and February 2021. Anti-müllerian hormone (AMH), follicle-stimulating hormone (FSH), and estradiol (E2) were measured as indicators of ovarian reserve. Urinary BPA, BPF, and BPS concentrations were quantified by ultra-high-performance liquid chromatography-triple quadruple mass spectrometry (UHPLC-MS/MS). Linear and logistic regression models were applied to assess the associations between urinary BPA, BPF, and BPS levels and indicators of ovarian reserve and DOR, respectively. Restricted cubic spline (RCS) models were further utilized to explore potential non-linear associations. Our results showed that urinary BPS concentrations were negatively associated with AMH (β = - 0.287, 95 %CI: - 0.505, - 0.070, P = 0.010) and this inverse relationship was further confirmed in the RCS model. In addition, higher levels of BPA and BPS exposure were associated with increased DOR risk (BPA: OR = 7.112, 95 %CI: 1.247, 40.588, P = 0.027; BPS: OR = 6.851, 95 %CI: 1.241, 37.818, P = 0.027). No significant associations of BPF exposure with ovarian reserve. Our findings implied that higher BPA and BPS exposure may be related to decreased ovarian reserve.

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.

Acetate circumvents impaired metabolic switch in skeletal muscle of letrozole-induced PCOS rat model by suppression of PDK4/NLRP3

OBJECTIVES

Endocrine disorders in women of childbearing age, including polycystic ovarian syndrome (PCOS), have been linked to skeletal muscle insulin resistance with multiple post-receptor intracellular defects, disrupting metabolic flexibility. Short-chain fatty acids, such as acetate have been suggested as a metabolic modulator. However, the effects of acetate on aberrant metabolic switch in skeletal muscle of individuals with PCOS are unknown. This study therefore hypothesized that acetate would circumvent impaired metabolic switch in the skeletal muscle of a letrozole-induced PCOS rat model, probably by suppression of PDK4/NLRP3.

METHODS

Eight-wk-old female Wistar rats were assigned into three groups (n = 6), which received vehicle, letrozole (1 mg/kg), and letrozole plus acetate (200 mg/kg), respectively. The administrations were done by oral gavage for 21 d. .

RESULTS

Animals with PCOS had insulin resistance, increased testosterone, and leptin, as well as decreased adiponectin level. Additionally, the skeletal muscle was also characterized with increased lipid deposition, malondialdehyde, inflammatory mediators (nuclear factor-κB and tumor necrosis factor-α), lactate dehydrogenase, lactate/pyruvate ratio, HDAC and PDK 4 with corresponding decrease in glycogen synthesis, glutathione and NrF2. Besides, immunohistochemical evaluation showed severe expression of inflammasome and apoptosis in PCOS animals. Nonetheless, supplementation with acetate significantly attenuated these perturbations.

CONCLUSIONS

The present results demonstrate aberrant metabolic switch in the skeletal muscle of PCOS animals, which is accompanied by excessive inflammation, oxidative stress and elevated levels of histone deacetylase and PDK4. The results suggested that histone deacetylase inhibitor, acetate circumvents impaired metabolic switch in the skeletal muscle of PCOS rats by suppression of PDK4/NLRP3 inflammasome.

Interactions of Bisphenol A with Artemia franciscana and the ameliorative effect of probiotics

In the present study, the bidirectional interactions of Artemia franciscana with BPA, administered either alone or following treatment with the probiotics Bacillus subtilis, Lactococcus lactis or Lactobacillus plantarum, were evaluated. A 24 h exposure to BPA below LC₅₀ induced oxidative stress to Artemia, indicated by diminished activity of superoxide dismutase, glutathione reductase, glutathione transferase and phenoloxidase, increased lipid peroxidation and decreased survival. Probiotic treatment prior to BPA exposure, led to increased survival, reduced lipid peroxidation and increased enzyme activities. BPA quantification in Artemia and its culture medium, showed a time dependent reduction in its levels, more evident in probiotic series, indicating its biotransformation. ESI-MS analysis confirmed the presence of the tentative BPA metabolites hydroquinone and BPA-sulfate, while BPA-disulfate formation was confirmed in only in the probiotic series. Our results provide evidence that probiotics alleviate the oxidative stress response induced by BPA, by enhancing the BPA biotransformation ability of Artemia.

The Emerging Role of Epigenetics in Metabolism and Endocrinology

Each cell in a multicellular organism has its own phenotype despite sharing the same genome. Epigenetics is a somatic, heritable pattern of gene expression or cellular phenotype mediated by structural changes in chromatin that occur without altering the DNA sequence. Epigenetic modification is an important factor in determining the level and timing of gene expression in response to endogenous and exogenous stimuli. There is also growing evidence concerning the interaction between epigenetics and metabolism. Accordingly, several enzymes that consume vital metabolites as substrates or cofactors are used during the catalysis of epigenetic modification. Therefore, altered metabolism might lead to diseases and pathogenesis, including endocrine disorders and cancer. In addition, it has been demonstrated that epigenetic modification influences the endocrine system and immune response-related pathways. In this regard, epigenetic modification may impact the levels of hormones that are important in regulating growth, development, reproduction, energy balance, and metabolism. Altering the function of the endocrine system has negative health consequences. Furthermore, endocrine disruptors (EDC) have a significant impact on the endocrine system, causing the abnormal functioning of hormones and their receptors, resulting in various diseases and disorders. Overall, this review focuses on the impact of epigenetics on the endocrine system and its interaction with metabolism.

Polycystic Ovary Syndrome and Endocrine Disruptors (Bisphenols, Parabens, and Triclosan)-A Systematic Review

Exposure to endocrine disrupting chemicals (EDCs) can result in alterations of the female reproductive system, including polycystic ovary syndrome (PCOS). The aim of this review was to summarize the knowledge about the association of EDCs (bisphenols, parabens, and triclosan) with PCOS. We conducted an electronic literature search using PubMed for studies published between January 2007 and October 2022 on EDCs related to PCOS, and evaluated the association of PCOS with bisphenols, parabens and triclosan in 15 articles. Most studies revealed significantly higher plasma, urinary or follicular fluid levels of bisphenol A (BPA) in women with PCOS, and some showed a positive correlation of BPA with insulin resistance, polycystic morphology on ultrasound, hepatic steatosis, bilirubin levels, as well as free androgen index, androstenedione and testosterone serum levels, and markers of low-grade chronic inflammation. There was a negative correlation of BPA with markers of ovarian reserve, sex hormone binding globulin and vitamin D-binding protein. Parabens and triclosan have been studied in only one study each, with no significant associations with PCOS observed. Our review revealed an association of BPA with PCOS and negative effects of BPA on human ovaries; more research is needed to assess the potential associations of parabens and triclosan with PCOS.

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.

Endocrine Disrupting Chemicals in Polycystic Ovary Syndrome: The Relevant Role of the Theca and Granulosa Cells in the Pathogenesis of the Ovarian Dysfunction

Polycystic ovary syndrome (PCOS) is the most common heterogeneous endocrine disorder among women of reproductive age. The pathogenesis of PCOS remains elusive; however, there is evidence suggesting the potential contribution of genetic interactions or predispositions combined with environmental factors. Among these, endocrine disrupting chemicals (EDCs) have been proposed to potentially contribute to the etiology of PCOS. Granulosa and theca cells are known to cooperate to maintain ovarian function, and any disturbance can lead to endocrine disorders, such as PCOS. This article provides a review of the recent knowledge on PCOS pathophysiology, the role of granulosa and theca cells in PCOS pathogenesis, and the evidence linking exposure to EDCs with reproductive disorders such as PCOS.

Bisphenol-A and Female Fertility: An Update of Existing Epidemiological Studies

Humans interfere with a variety of endocrine disruptors on a daily basis, which may result in adverse health effects. Among them, Bisphenol-A (BPA) is the most debated endocrine disruptor, despite being widely studied, regarding its effects on fertility. The aim of this review was to investigate the interrelation of BPA and female fertility. PubMed (Medline) was searched from 2013 until 2022 to identify epidemiological studies that report the association of BPA with fertility parameters, in vitro fertilization (IVF) outcomes, polycystic ovarian syndrome (PCOS) and endometriosis. Regarding general fertility, most studies report an inverse association between BPA and ovarian reserve markers, namely antral follicle count (AFC) and anti-Müllerian hormone (AMH). The BPA and estradiol (E2) levels did not correlate significantly in the majority of studies. No definite conclusions can be reached regarding BPA and IVF endpoints or endometriosis. Lastly, most studies report higher prevalence of PCOS in women with higher BPA concentrations, although no casualty has been proven. Although most studies fail to reach definite conclusion regarding the impact of BPA on fertility, there is accumulating evidence suggesting a negative role of BPA in female reproductive health.

Association between co-exposure to phenols and phthalates mixture and infertility risk in women

BACKGROUND

Exposure to phenols and phthalates has been separately linked to increased risks of infertility in women of reproductive age. However, the combined effect of phenols and phthalates exposure on infertility has not been explored.

METHODS

Data from the National Health and Nutrition Examination Surveys (NHANES) were used. A total of 857 women of reproductive age (18-45 years) with available information on urinary phenol and phthalate metabolites, reproductive questionnaires, and covariates were included in the present study. The definition of infertility was based on self-reports. Multivariable logistic regression, principal component analysis (PCA), and Bayesian kernel machine regression (BKMR) with stratified variable selection were applied to determine what associations were found between combined exposure to these mixtures and risk of infertility among women of reproductive age.

RESULTS

After adjusting for potential confounders, bisphenol A (BPA), mono(3-carboxypropyl) phthalate (MCPP) and four di(2-ethylhexyl) phthalate (DEHP) metabolites [mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP)] were positively associated with infertility. PCA revealed that the DEHP-BPA factor's PC score was significantly positively related to the likelihood of infertility [adjusted odds ratio (aOR) = 1.45; 1.08, 1.82]. The DEHP-BPA component consistently had the highest group posterior inclusion probability (PIP) in BKMR models. The BKMR model also found that MEOHP, MEHHP, and BPA were positively associated with infertility risk when the remaining combination concentrations were held at their median values. In addition, we observed that the probability of infertility increased dramatically as the quantiles of total mixture concentration increased.

CONCLUSION

Our findings indicate that a combination of phenol and phthalate metabolites is linked to infertility among reproductive-age women. BPA and DEHP, in particular, are significantly related to the risk of infertility.

Effect of bisphenol F on sexual performance and quality of offspring in Male Wistar rats

This study investigated the effect of BPF on male sexual performance and the quality of the offspring. Eighty (80) Male Wistar rats (n = 10 per group) were randomised into normal saline-treated control and control recovery, BPF varied doses (low, medium, and high), and BPF varied doses recovery (low, medium, and high) groups. The study was terminated after 28 days of BPF oral administration. The animals were sacrificed after 24 h from the last dose, while those in the recovery groups were allowed to recover for another 28 days before being sacrificed. BPF administration was found to impair sexual performance, as shown by a significant decrease in frequencies (mount, intromission, and ejaculation frequencies) and an increase in latencies (mount, intromission, and ejaculation latencies). This was accompanied by a significant decrease in plasma LH, FSH, testosterone, dopamine, acetylcholinesterase, nitric oxide, and penile cyclic guanosine monophosphate (cGMP) level. The level of plasma oestrogen and prolactin were significantly increased following BPF administration. BPF also reduced the sperm count, morphology, viability, and motility. Furthermore, BPF reduced fertility success and index, litter size, litter weight, and offspring survival rate. These toxic effects of BPF were dose-dependent and were not reversed by withdrawal following 28 days of recovery. This study concluded that BPF disrupts sexual competence and offspring quality by suppressing the hypothalamic-pituitary-gonadal axis and mediating oestrogen-induced hyperprolactinemia. These events were associated with reduced fertility index and success, poor semen quality, and reduced offspring survival rate. The observed toxic effects of BPF were dose-dependent and not reversed by cessation of BPF exposure.

Comparison of efficacies between ultrasound-guided curettage combined with hysteroscopic electro-resection after injection of pituitrin and hysteroscopic electro-resection after methotrexate chemotherapy in the treatment of cesarean scar pregnancy

To compare the efficacies between ultrasound-guided curettage combined with hysteroscopic electro-resection after injection of pituitrin and hysteroscopic electro-resection after methotrexate chemotherapy in the treatment of caesarean scar pregnancy (CSP). 60 patients with CSP admitted to our hospital were selected as the study subjects, and divided into observation group (n = 35) and control group (n = 25) in accordance with the therapeutic options. The observation group was treated with ultrasound-guided curettage combined with hysteroscopic electro-resection after injection of pituitrin, while the control group was treated with hysteroscopic electro-resection after methotrexate chemotherapy. The observation group was superior to the control group in the amount of intraoperative haemorrhage, in-hospital costs, and postoperative time to control vaginal haemorrhage, time to return to a normal serum human chorionic gonadotropin (HCG) level. The observation group had a lower incidence rate of adverse reactions (5.71% vs. 28.00%, p < .05) and a higher first-attempt success rate for treatment (85.71% vs. 84.00%, p > .05) compared with the control group. Ultrasound-guided curettage combined with hysteroscopic electro-resection after injection of pituitrin, exhibiting a higher efficacy, can more effectively shorten the postoperative recovery, reduce adverse reactions, and improve the postoperative quality of life in patients with CSP. IMPACT STATEMENTWhat is already known on this subject? Caesarean scar pregnancy (CSP), a rare form of ectopic pregnancy where the fertilised egg is implanted in the muscle or fibrous tissue of the scar after a previous caesarean section (CS), is a long-term complication of CS that may be life-threatening for parturients. Some therapies have been used to treat CSP, such as uterine artery embolisation and uterine artery embolisation chemotherapy combined with curettage, but the potential adverse effects may affect the ovarian reserve and even affecting the fertility of patients.What do the results of this study add? This study showed that ultrasound-guided curettage combined with hysteroscopic electro-resection after injection of pituitrin, exhibiting a higher efficacy, can more effectively shorten the postoperative recovery, reduce adverse reactions, and improve the postoperative quality of life in patients with CSP.What are the implications of these findings for clinical practice and/or further research? The findings of this study may provide some references for the clinical practitioners and further research and may contribute to the treatment of CSP.

Implications of endocrine-disrupting chemicals on polycystic ovarian syndrome: A comprehensive review

Polycystic ovarian syndrome (PCOS) is a complex multifactorial disorder of unknown pathogenesis in which genetic and environmental factors contribute synergistically to its phenotypic expressions. Endocrine-disrupting chemicals (EDCs), a group of widespread pollutants freely available in the environment and consumer products, can interfere with normal endocrine signals. Extensive evidence has shown that EDCs, environmental contributors to PCOS, can frequently induce ovarian and metabolic abnormalities at low doses. The current research on environmental EDCs suggests that there may be link between EDC exposure and PCOS, which calls for more human bio-monitoring of EDCs using highly sophisticated analytical techniques for the identification and quantification and to discover the underlying pathophysiology of the disease. This review briefly elaborated on the general etiology of PCOS and listed various epidemiological and experimental data from human and animal studies correlating EDCs and PCOS. This review also provides insights into various analytical tools and sample preparation techniques for biomonitoring studies for PCOS risk assessment. Furthermore, we highlight the role of metabolomics in disease-specific biomarker discovery and its use in clinical practice. It also suggests the way forward to integrate biomonitoring studies and metabolomics to underpin the role of EDCs in PCOS pathophysiology.

Royal Jelly as a Nutraceutical Natural Product with a Focus on Its Antibacterial Activity

Royal jelly (RJ) is one of the most valued natural products and is known for its health-promoting properties. Due to its therapeutic effects, it has been used in medicine since antiquity. Nowadays, several studies indicate that RJ acts as a powerful antimicrobial agent. Indeed, researchers shed light on its antioxidant and anticancer activity. RJ’s biological properties are related to its bioactive compounds, such as proteins, peptides, phenolic, and fatty acids. The aim of this review is to highlight recent findings on RJ’s main bioactive compounds correlated with its health-promoting properties. The available literature suggests that these bioactive compounds can be used as an alternative approach in order to enhance human health. Moreover, throughout this paper, we underline the prominent antibacterial effect of RJ against several target bacterial strains. In addition, we briefly discuss other therapeutic activities, such as antioxidative and anticancer effects, of this outstanding natural product.

Review on bisphenol A and the risk of polycystic ovarian syndrome: an insight from endocrine and gene expression

Bisphenol A (BPA) is one of the most widely studied endocrine disrupting chemicals because of its structural similarity to 17-β estradiol; its ability to bind as an agonist/antagonist to estrogen receptors elicits adverse effects on the functioning of the metabolic and endocrinal system. Therefore, BPA has been thoroughly scrutinized concerning its disruption of pathways like lipid metabolism, steroidogenesis, insulin signaling, and inflammation. This has resulted in reports of its correlation with various aspects of cardiovascular diseases, obesity, diabetes, male and female reproductive disorders, and dysfunctions. Among these, the occurrence of the polycystic ovarian syndrome (PCOS) in premenopausal women is of great concern. PCOS is a highly prevalent disorder affecting women in their reproductive age and is clinically characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology, along with metabolism-related dysfunctions like hyperinsulinemia, obesity, and insulin resistance. In this review, we analyzed certain researched effects of BPA, while focusing on its ability to alter the expression of various significant genes like GnRH, AdipoQ, ESR1, StAR, CYP11A1, CYP19A1, and many more involved in the pathways and endocrine regulation, whose disruption is commonly associated with the clinical manifestations of PCOS.

Killing two birds with one stone: Pregnancy is a sensitive window for endocrine effects on both the mother and the fetus

Pregnancy is a complex process requiring tremendous physiological changes in the mother in order to fulfill the needs of the growing fetus, and to give birth, expel the placenta and nurse the newborn. These physiological modifications are accompanied with psychological changes, as well as with variations in habits and behaviors. As a result, this period of life is considered as a sensitive window as impaired functional and physiological changes in the mother can have short- and long-term impacts on her health. In addition, dysregulation of the placenta and of mechanisms governing placentation have been linked to chronic diseases later-on in life for the fetus, in a concept known as the Developmental Origin of Health and Diseases (DOHaD). This concept stipulates that any change in the environment during the pre-conception and perinatal (in utero life and neonatal) period to puberty, can be "imprinted" in the organism, thereby impacting the health and risk of chronic diseases later in life. Pregnancy is a succession of events that is regulated, in large part, by hormones and growth factors. Therefore, small changes in hormonal balance can have important effects on both the mother and the developing fetus. An increasing number of studies demonstrate that exposure to endocrine disrupting compounds (EDCs) affect both the mother and the fetus giving rise to growing concerns surrounding these exposures. This review will give an overview of changes that happen during pregnancy with respect to the mother, the placenta, and the fetus, and of the current literature regarding the effects of EDCs during this specific sensitive window of exposure.

Endocrine disruptors, obesity, and cytokines - how relevant are they to PCOS?

As environmental and genetic components contribute to the PCOS expression, we compared levels of endocrine disruptors, steroid hormones, cytokines, and metabolic parameters in twenty healthy, nine normal-weight PCOS women, and ten obese PCOS women. Steroid hormones, bisphenols (BPA, BPS, BPF, BPAF) and parabens (methyl-, ethyl-, propyl-, butyl-, benzyl-parabens) were measured by liquid chromatography-tandem mass spectrometry. Differences between the groups were assessed using the Mann-Whitney U test. Spearman correlation coefficients were calculated for the individual parameters relationship. Significantly higher levels of BPA, anti-Müllerain hormone, lutropine, lutropine/folitropine ratio, testosterone, androstenedione, 7beta-OH-epiandrosterone, and cytokines (IL-6, VEGF, PDGF-bb), were found in normal-weight PCOS women compared to controls. Between normal-weight and obese PCOS women, there were no differences in hormonal, but in metabolic parameters. Obese PCOS women had significantly higher insulin resistance, fatty-liver index, triglycerides, cytokines (IL-2, IL-13, IFN-gamma). In healthy, but not in PCOS, women, there was a positive correlation of BPA with testosterone, SHBG with lutropine, and folitropine, while testosterone negatively correlated with SHBG. In obese women with PCOS, insulin resistance negatively correlated with SHBG and estradiol. No differences were observed in the paraben exposure. Levels of BPA were higher in PCOS women, indicating its role in the etiology. Obesity significantly worsens the symptoms.

Urinary Bisphenol A Concentrations and Parameters of Ovarian Reserve among Women from a Fertility Clinic

Background: Human exposure to environmentally widespread endocrine disruptors, especially bisphenol A (BPA), has been suggested to affect reproductive health. Animal studies indicate that BPA may play a role in the process of reproduction and impact on maturing oocytes, meiotic cell division or fertilization rate. Nevertheless, data regarding the effects of exposure to BPA on women’s ovarian function are still limited. Therefore, the aim of the current study is to assess the effects of environmental exposure to BPA on ovarian reserve. Methods: The study participants consisted of 511 women in reproductive age (25–39 years) who attended an infertility clinic for diagnosis, due to the couples’ infertility. BPA urinary concentrations were assessed by the validated gas chromatography ion-trap mass spectrometry method. The ovarian reserve was assessed using ovarian reserve parameters: Hormones concentrations: E2 (estradiol), FSH (follicle stimulating hormone), AMH (anti-Müllerian hormone), and AFC (antral follicle count). Results: In the present study, the negative association between BPA urinary concentrations and AMH (p = 0.02) and AFC (p = 0.03) levels was found. Exposure to BPA was not related to other examined parameters of ovarian reserve (FSH, E2). Conclusions: Our results suggest that BPA exposure may affect women ovarian reserve parameters and reduce ovarian reserve. As this is one of the first studies of its kind, the findings need confirmation in a further investigation.

Endocrine-Disrupting Compounds: An Overview on Their Occurrence in the Aquatic Environment and Human Exposure

Endocrine-disrupting compounds (EDCs) as emerging contaminants have accumulated in the aquatic environment at concentration levels that have been determined to be significant to humans and animals. Several compounds belong to this family, from natural substances (hormones such as estrone, 17-estradiol, and estriol) to synthetic chemicals, especially pesticides, pharmaceuticals, and plastic-derived compounds (phthalates, bisphenol A). In this review, we discuss recent works regarding EDC occurrence in the aquatic compartment, strengths and limitations of current analytical methods used for their detection, treatment technologies for their removal from water, and the health issues that they can trigger in humans. Nowadays, many EDCs have been identified in significant amounts in different water matrices including drinking water, thus increasing the possibility of entering the food chain. Several studies correlate human exposure to high concentrations of EDCs with serious effects such as infertility, thyroid dysfunction, early puberty, endometriosis, diabetes, and obesity. Although our intention is not to explain all disorders related to EDCs exposure, this review aims to guide future research towards a deeper knowledge of EDCs’ contamination and accumulation in water, highlighting their toxicity and exposure risks to humans.

Endocrine disrupting chemical Bisphenol A and its potential effects on female health

BACKGROUND AND AIM

A large number of chemical compounds with endocrine-disrupting activity have been documented. These chemicals are ubiquitous and widely used in many products of our daily lives. Bisphenol A (BPA) is among the most common Endocrine Disrupting Chemical (EDC) that has been used for many years in the manufacture of polycarbonate plastics and epoxy resins. There is growing evidence that exposure to these EDCs poses a possible health risk. This review focuses on the effect of EDCs, in particular, BPA on female reproduction and Polycystic Ovary Syndrome (PCOS), which is the most prevalent endocrine disorder of reproductively aged women.

METHODS

A relevant literature survey was conducted with Google scholar and Pubmed using several appropriate keywords to select the most relevant studies evaluating the role of endocrine disrupting-chemicals in female reproduction.

RESULTS

The female menstrual cycle and fertility are very sensitive to hormonal imbalance and alteration in endocrine function during critical times and different stages of lifecycle owing to EDC exposure results in many abnormalities like menstrual irregularities, impaired fertility, PCOS, and Endometriosis among others. BPA is the most extensively studied EDC worldwide and has been strongly associated with female reproductive health.

CONCLUSION

EDCs lead to deleterious effects on human health including reproductive health which are of global concern. Exposure to EDCs in early life can elicit disease in adult life and maybe even transgenerational. There is an immediate need to minimize the ill effect of EDCs which can be tackled through the collection of more data to clarify the clinical implications of EDCs.

Effects of bisphenol A on cardiovascular disease: An epidemiological study using National Health and Nutrition Examination Survey 2003-2016 and meta-analysis

As the most widely consumed endocrine-disrupting chemical, bisphenol A (BPA) has been linked to reproductive dysfunction, diabetes mellitus, and obesity. However, the evidence for an association between BPA and cardiovascular disease (CVD) remains insufficient. In the present study, we aimed to identify the association between BPA and CVD, using data from the 2003-2016 National Health and Nutrition Examination Surveys (NHANES). We estimated urine BPA concentration after adjustments for creatinine (ng/mg) and normalized the asymmetrical distribution using natural logarithmic transformation (ln-BPA/Cr). A multivariate logistic regression was performed to evaluate the odds ratio (OR) and 95% confidence interval (CI) for CVD, with ln-BPA/Cr concentration as predictor. We then performed a Mantel-Haenszel meta-analysis with five eligible studies and NHANES 2003-2016 data. Our subjects were 11,857 adults from the NHANES data. After adjusting for age, sex, race/ethnicity, body mass index (BMI), cigarette smoking, diabetes status, hypertension, and dyslipidemia, OR between ln-BPA/Cr and CVD was 1.13 (95% CI: 1.02-1.24). After propensity-score-matching with age, sex, race/ethnicity, BMI, cigarette smoking, diabetes, hypertension, and dyslipidemia, OR continued to be significant for the association between ln-BPA/Cr and CVD (OR: 1.18, 95% CI: 1.04-1.33). A restricted cubic spline plot of this relationship revealed a dose-dependent increase in OR. However, untransformed BPA had a linear relationship with CVD only at low concentrations, whereas the OR of BPA plateaued at high concentrations. In a meta-analysis with 22,878 subjects, after adjusting for age, sex, and various cardiometabolic risk factors, OR was 1.13 (95% CI, 1.03-1.23). In conclusion, our study provides additional epidemiological evidence supporting an association between BPA and CVD.

Bisphenol A promotes autophagy in ovarian granulosa cells by inducing AMPK/mTOR/ULK1 signalling pathway

BACKGROUND

Bisphenol A (BPA) is a widespread endocrine-disrupting chemical with estrogen like effects, which could interfere with the human reproductive system by disrupting the normal function of granulosa cells (GCs) leading to abnormal ovarian function. However, the mechanism of its toxicity on human GCs has not been clearly described thus far.

METHODS

106 normogonadotropic infertile women undergoing their first in-vitro fertilization-embryo transfer (IVF-ET) cycle were recruited. Urinary BPA level and the early outcomes of IVF-ET were analysed. Patients were divided to low and high BPA exposure groups using the median urinary BPA concentration as the cut-off value. In-vivo and in-vitro studies were conducted using mice and human granulosa cell line (KGN cells). Female Kunming mice approximately 6-8 weeks of age were poisoned with BPA at different dosages (1, 10 or 100 μg/kg) by oral gavage once daily for 2 weeks, while KGN cells were exposed to BPA at the concentration of 1, 10 or 100 nM for 24 h, 48 h or 72 h. BPA-induced ovarian morphologic changes were analysed by histopathology investigation. Cell viability and apoptosis were evaluated using CCK-8, TUNEL and flowcytometric, respectively. Hormone levels were determined using ELISA and the molecular mechanism studies were conducted using immunofluorescence, RT-PCR and western blots.

RESULTS

The oocyte retrieval rate, maturation rate and embryo implantation rate significantly decreased with the higher level of urinary BPA concentration. Peak E2 level was lower in high BPA group, but no statistical significance could be observed. In BPA treated mice, cystic dilation of the follicles with a decreased number of GCs could be observed histopathologically. Decreased E2, P4 and AMH level and GCs autophagy could be detected both in-vivo and in-vitro with the activation of AMPK/mTOR/ULK1 signalling pathway. As being confirmed in KGN cells, phosphorylated AMPK and ULK1 increased while phosphorylated mTOR decreased, and by inhibition autophagy using knockdown of AMPK or 3-MA, adverse effects of BPA exposure in-vitro could be reversed.

CONCLUSION

BPA exposure might abnormally influence human ovarian functions leading to abnormal folliculogenesis by activation of autophagy in GCs through AMPK/mTOR/ULK1 pathway.

The Association of Ovarian Reserve with Exposure to Bisphenol A and Phthalate in Reproductive-aged Women

BACKGROUND

Exposure to endocrine disrupting chemicals (EDCs) that influence the hormonal and homeostatic systems is known to be associated with gynecologic health risks in many countries. In this study, we evaluated exposure to EDCs associated with diminished ovarian reserve (DOR) and gynecologic health risks.

METHODS

This cross-sectional study was performed from September 2014 to November 2014 and included 307 Korean reproductive-aged women. Anthropometric measurements, laboratory tests with urine and blood sampling and pelvic ultrasound examinations were performed.

RESULTS

Urinary bisphenol A (BLA) level was significantly higher in the DOR group with anti-Müllerian hormone lower than 25 percentile (1.89 ± 2.17 ug/g and 1.58 ± 1.08 ug/g, P < 0.05). Urinary mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate and mono-N-butyl phthalate, and substrates of phthalate were evaluated and no significant difference was observed between the DOR group and non-DOR group. Logistic regression analysis suggested an increase in infertility in high BPA exposure group and the odds ratio (OR, 4.248) was statistically significant after adjustment for age, birth control pills, and the age of menarche, parity, and waist circumference. High phthalate exposure was associated with endometrial polyp after adjustment (OR, 2.742).

CONCLUSION

BPA exposure might be associated with DOR and infertility. Meanwhile, endometrial polyp is increased in women with high phthalate exposure. Therefore, the risk of exposures to EDCs for reproduction should be a matter of concern in reproductive-aged women.

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 and polycystic ovary syndrome: a review of the literature

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age with reproductive, metabolic and endocrine implications. While the exact pathophysiological mechanisms of the syndrome are unknown, its heterogeneity suggests a multifactorial causal background. In the last two decades, numerous environmental chemicals, including Bisphenol-A (BPA) that is used in the synthesis of polycarbonate plastics, have been proposed as potential contributors to the aetiology of PCOS. This review provides a holistic overview of the available data regarding the possible relation of PCOS with BPA exposure. We have included a total number of 24 studies. Eleven human case-control and 13 animal studies provided data regarding this potential relation. Accumulating evidence suggests that a correlation between high levels of BPA and the presence of PCOS may exist. Contradicting results from human and animal studies, however, render it difficult to conclude on the exact role of BPA in the pathogenesis of PCOS. BPA may constitute a consequence of the syndrome rather than a cause, but further research is still needed to clarify this. Continued efforts to study the early origins of PCOS, using prospective-designed studies, are required to identify the exact effect of BPA on women with PCOS.

Bisphenol A decreases progesterone synthesis in human ovarian granulosa cells

Evidences indicate that the decline of female fertility is becoming a common problem over the past few decades. Environmental exposure of Bisphenol A (BPA) has been considered as an endocrine-disrupting chemical deleteriously affecting human reproductions. To better understand the effect of BPA exposure on human ovarian granulosa cells, we treated human ovarian granulosa cell line (KGN) with increasing concentrations (0.1, 1, 10, and 100 μM) of BPA for 24 hr. About 0.1, 1, and 10 μM BPA did not significantly affect the viability of KGN while 100 μM of BPA caused a statistically significant decrease in the viability of KGN. Treatment KGN with 10 μM BPA resulted in a significant decrease in progesterone biosynthesis. The treatment also significantly increased the expression of ATP binding cassette subfamily A member 1 (ABCA1) and steroidogenic acute regulatory protein (STAR). In the current study, exposure to BPA could lead to decreased progesterone production probably through the upregulation of ABCA1 in human granulosa cells.

Environmental Endocrine-Disrupting Chemical Exposure: Role in Non-Communicable Diseases

The exponential growth of pollutant discharges into the environment due to increasing industrial and agricultural activities is a rising threat for human health and a biggest concern for environmental health globally. Several synthetic chemicals, categorized as potential environmental endocrine-disrupting chemicals (EDCs), are evident to affect the health of not only livestock and wildlife but also humankind. In recent years, human exposure to environmental EDCs has received increased awareness due to their association with altered human health as documented by several epidemiological and experimental studies. EDCs are associated with deleterious effects on male and female reproductive health; causes diabetes, obesity, metabolic disorders, thyroid homeostasis and increase the risk of hormone-sensitive cancers. Sewage effluents are a major source of several EDCs, which eventually reach large water bodies and potentially contaminate the drinking water supply. Similarly, water storage material such as different types of plastics also leaches out EDCs in drinking Water. Domestic wastewater containing pharmaceutical ingredients, metals, pesticides and personal care product additives also influences endocrine activity. These EDCs act via various receptors through a variety of known and unknown mechanisms including epigenetic modification. They differ from classic toxins in several ways such as low-dose effect, non-monotonic dose and trans-generational effects. This review aims to highlight the hidden burden of EDCs on human health and discusses the non-classical toxic properties of EDCs in an attempt to understand the magnitude of the exposome on human health. Present data on the environmental EDCs advocate that there may be associations between human exposure to EDCs and several undesirable health outcomes that warrants further human bio-monitoring of EDCs.

Urinary bisphenol A concentrations and in vitro fertilization outcomes among women from a fertility clinic

Bisphenol A (BPA) is a widespread environmental endocrine disrupting chemical. Although many animals and in vitro studies reported that BPA may affect female fertility through the effect on maturing oocytes and meiotic cell division, but the data from human studies are limited and inconclusive. The study was conducted to examine the association between urinary BPA concentration and in vitro reproductive outcomes (metaphase II (MII) oocyte yield, top quality embryo, fertilization rate, implantation rate and clinical pregnancy) among women from an infertility clinic. The study participants were enrolled in the Infertility Center in Poland. 450 women aged 24-44 (n = 674 IVF cycles) provided urine samples. The urinary concentrations of BPA were evaluated using validated gas chromatography ion-tap mass spectrometry method. Clinical outcomes of IVF treatment were abstracted from patients electronic chart records. To assess the relationship between urinary BPA concentrations early examined reproductive outcomes generalized linear mixed models were used. The detection rate of BPA in urine samples was 98% and the geometric mean 1.59 ± 2.15 ng/ml. A significant decrease was observed between urinary concentration of BPA and implantation (p = 0.04) and decreased MII oocyte count (p = 0.03). There was no association between other examined IVF outcomes: embryo quality, fertilization rate and clinical pregnancy and BPA exposure. Exposure to BPA may have a negative effect during the early stages of human development. The studies among the larger and more diverse population are needed to confirm the results.

The association of bisphenol A exposure with premature ovarian insufficiency: a case-control study

BACKGROUND

A few epidemiological investigations and animal studies have demonstrated that bisphenol A (BPA) may affect female reproductive health. However, no epidemiologic study has investigated the relationship between BPA exposure and the risk of premature ovarian insufficiency (POI).

METHODS

In this case-control study, urinary concentrations of BPA and serum levels of reproductive hormone were measured. Associations between BPA concentrations and the risk of POI and POI-related hormone levels were estimated.

RESULTS

Among BPA quartiles, no obvious association was found between BPA levels and the risk of POI (p = 0.603). Although the adjusted odds ratio (OR) of POI was slightly increased for participants in the highest BPA concentration quartile, the association was not statistically significant (OR = 1.282, 95% confidence interval [CI] 0.615-2.049 for the highest vs. lowest quartile, p = 0.508). Although follicle stimulating hormone (FSH) and anti-Mullerian hormone (AMH) levels showed no tendency of an association with BPA (p = 0.941 and p = 0.876 for FSH and AMH, respectively), the highest quartile of luteinizing hormone was significantly positively associated with BPA levels (OR = 1.333, 95% CI 0.986-1.803, p = 0.042).

CONCLUSIONS

The urinary concentrations of BPA determined in this study were consistent with the range of exposure currently observed in Chinese women. However, BPA exposure at a relatively low level is not associated with POI in Chinese women. Further epidemiological studies are needed to confirm our findings.

The Impact of Di-2-Ethylhexyl Phthalate on Sperm Fertility

A growing number of studies point to reduced fertility upon chronic exposure to endocrine-disrupting chemicals (EDCs) such as phthalates and plasticizers. These toxins are ubiquitous and are often found in food and beverage containers, medical devices, as well as in common household and personal care items. Animal studies with EDCs, such as phthalates and bisphenol A have shown a dose-dependent decrease in fertility and embryo toxicity upon chronic exposure. However, limited research has been conducted on the acute effects of these EDCs on male fertility. Here we used a murine model to test the acute effects of four ubiquitous environmental toxins: bisphenol A (BPA), di-2-ethylhexyl phthalate (DEHP), diethyl phthalate (DEP), and dimethyl phthalate (DMP) on sperm fertilizing ability and pre-implantation embryo development. The most potent of these toxins, di-2-ethylhexyl phthalate (DEHP), was further evaluated for its effect on sperm ion channel activity, capacitation status, acrosome reaction and generation of reactive oxygen species (ROS). DEHP demonstrated a profound hazardous effect on sperm fertility by producing an altered capacitation profile, impairing the acrosome reaction, and, interestingly, also increasing ROS production. These results indicate that in addition to its known chronic impact on reproductive potential, DEHP also imposes acute and profound damage to spermatozoa, and thus, represents a significant risk to male fertility.

Impact of Bisphenol A on Gonadotropic Hormone Levels in Children with Autism Spectrum Disorders

Early developmental exposures to endocrine disruptors including bisphenol A (BPA) may affects the body's endocrine system producing adverse neurologic, reproductive, cardiovascular, metabolic, and immune effects in humans. Many studies show the effect of BPA on human reproduction at lower concentrations than that of the safety limit recommendations. However, limited studies have been associated between environmental exposure of BPA and gonadotropic hormone levels in children with autism spectrum disorders (ASDs). This study was done to evaluate association between the serum levels of hormones; follicle-stimulating (FSH), inhibin B (INHB), and estradiol (E2) and BPA in 49 ASD children compared with 40 healthy control children. Serum levels of FSH, INHB, and E2 were lower in ASD group than that of control. Correlations between BPA and FSH, INHB, and E2 within autistic children were not significant. The observed results revealed that BPA may cause endocrine dysfunction in ASD children.

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.

Lifestyle and environmental contributions to ovulatory dysfunction in women of polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common reason of anovulatory infertility. Environmental factor is one of the main causes of PCOS, but its contribution to ovulatory dysfunction in PCOS remains unknown.

METHODS

A total of 2217 infertile women diagnosed as PCOS according to Rotterdam criteria were recruited, including 1979 women with oligo-anovulation (OA group) and 238 women with normal -anovulation (non OA group). Besides, 279 healthy control women of reproductive age were enrolled as controls.

RESULTS

Frequencies of snoring (PCOS-OA group, PCOS-non-OA group, control group: 29.30% vs 18.10% vs 11.50%, P < 0.01), smoking (37.70% vs 28.10% vs 12.20%, P < 0.01), plastic tableware usage (38.30% vs 28.10% vs 25.40%, P < 0.01) and indoor decoration (32.10% vs 24.80% vs 16.80%, P < 0.01) were highest in PCOS-OA group. After adjusted for multivariable, difference remained significant between PCOS-OA group and the other two groups. PCOS-OA women preferred a meat favorable diet compared to PCOS-non-OA group (54.60% vs 41.30%, P < 0.01). There was no difference between three groups in exercise, frequency of insomnia, and alcohol consumption.

CONCLUSIONS

Smoking, snoring, hyper-caloric diet, plastic tableware usage and indoor decoration were found to be associated with an increased risk for ovulatory dysfunction in women suffering from PCOS.

Urinary bisphenol A concentration is correlated with poorer oocyte retrieval and embryo implantation outcomes in patients with tubal factor infertility undergoing in vitro fertilisation

Bisphenol A (BPA) is a substance ubiquitously present in the environment, and its toxicity on reproductive function has been well characterised in animal models. However, it is still controversy about the effects of BPA exposure on human female reproduction. Therefore, in the present study, the associations of urinary BPA concentration with the outcomes of in vitro fertilisation (IVF) and embryo transfer from fresh and frozen cycles were analysed in the same cohort. 351 women who underwent IVF treatment from September 2013 to October 2016, at the Centre of Reproductive Medicine in the Women's Hospital School of Medicine at Zhejiang University were recruited. Single-spot urine samples were collected on the day of oocyte retrieval to detect BPA using solid-phase extraction and liquid chromatography coupled with tandem mass spectrometry. A multivariable generalised linear mixed model was used to evaluate the association between the urinary BPA concentration and IVF outcomes. After adjustment for age, body mass index, baseline follicle-stimulating hormone level, baseline oestradiol level, and antral follicle count, a significant decrease in the number of retrieved oocytes and in the rates of clinical pregnancy and implantation was observed in the patients with a high urinary BPA concentration. We concluded that BPA exposure exert negative effects on oocyte retrieval and embryo implantation in women undergoing IVF.

Effects of Bisphenol A Exposure during Pregnancy and lactation on Hippocampal Function in Newborn Rats

Bisphenol A (BPA) is widely used in industrial production. It is closely related to the growth and development of the nervous system, and can enter the fetal circulation through the placental barrier, and can be secreted through breast milk. The development of nervous system is very important in fetus and neonatal period. The purpose of this study is to investigate the effects of different doses of BPA on learning and memory function of nervous system in rats. Pregnant rats were randomly divided into three treatment groups (control group, 5 mg/kg/d, 50 mg/kg/d). All animals received BPA from the discovery of pregnancy to 21 days after birth. Results had shown that after high concentration BPA exposure, the increase of PS amplitude and f-EPSP slope in hippocampal CA1 area of male offspring was lower than that of control group. High concentration of BPA could inhibit Nestin, Cyclin D1, bcl-2 and Rac1 in male offspring rats and the expression of bax and RhoA was promoted by BPA. In summary, our study indicated that BPA exposure during pregnancy and lactation could impair the hippocampal function of male offspring by affecting the growth and apoptosis of hippocampal neurons, which might be due to the abnormal regulation of RhoA and Rac1.

Emerging Topics in Cardiometabolic and Psychologic Sequelae, Pathogenesis, and Treatment of Polycystic Ovarian Syndrome: A Review

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder, affecting 6–10% of reproductive age women and influences the reproductive, metabolic, dermatologic, and psychiatric health of affected girls and women. Despite its prevalence, the pathogenesis of the disease is largely unknown, and treatment options are limited. Thus, PCOS has been a ripe area for research in recent years, and novel etiologic pathways, diagnostic parameters, and treatment options are being explored. This review focuses on recent data suggesting pathogenic and therapeutic considerations, as well as the psychiatric and metabolic sequelae of PCOS.

Perfluoroalkyl substances exposure and risk of polycystic ovarian syndrome related infertility in Chinese women

Perfluoroalkyl substances (PFASs) are a family of synthetic, fluorinated organic compounds. They have been widely used in industrial applications and consumer products and widespread in the environment, wildlife and human. Experimental and epidemiologic evidence suggested that PFASs are capable of interfering with endocrine processes and have potential reproductive and developmental toxicities. Polycystic ovarian syndrome (PCOS), one of the main reasons of female infertility, is a common endocrine disorder in reproductive age women. We performed a case-control study to evaluate associations between PCOS-related infertility and PFASs concentrations in plasma. A total of 180 infertile PCOS-cases and 187 healthy controls were recruited from the Center for Reproductive Medicine of Shandong University. Blood specimens were collected at enrollment and analyzed for ten PFASs using liquid chromatography-tandem mass spectrometry. Multivariable logistic regression procedure was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for each PFAS. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were the dominant PFASs in the plasma of participants, with the median concentration of 5.07 ng/mL and 4.05 ng/mL, respectively. The median levels of individual PFAS were not significantly different between PCOS-cases and controls. While adjusted for the potential confounders (age, BMI, household income, education level, employment status, age at menarche, menstrual volume), the plasma concentration of perfluorododecanoic acid (PFDoA), a 12 carbons lengths of perfluorocarboxylic acids, was associated with a significantly increased risk of PCOS-related infertility (medium vs low tertile: OR = 2.36, 95% CI: 1.12, 4.99, P = 0.02; high vs low tertile: OR = 3.04, 95% CI: 1.19, 7.67, P = 0.02), with the P trend 0.01. No significant relationship was observed between PCOS-related infertility and other PFAS analytes in the adjusted model, despite perfluoroundecanoic acid showed a negative association (P trend 0.03). The potential reproductive health effects of PFASs and the underlying mechanisms merit further investigation in the future.

The Impact of Bisphenol A on Fertility, Reproductive System, and Development: A Review of the Literature

Bisphenol A (BPA) has been used since the 1950s, in food packaging, industrial materials, dental sealants, and personal hygiene products. Everyone is exposed to BPA through skin, inhalation, and digestive system. BPA disrupts endocrine pathways, because it has weak estrogenic, antiandrogenic, and antithyroid activities. Despite the rapid metabolism, BPA can accumulate in different tissues. Many researchers proved the impact of BPA on human development, metabolism, and finally reproductive system. There is increasing evidence that BPA has impact on human fertility and is responsible for the reproductive pathologies, e.g., testicular dysgenesis syndrome, cryptorchidism, cancers, and decreased fertility in male and follicle loss in female.

Associations of female exposure to bisphenol A with fecundability: Evidence from a preconception cohort study

BACKGROUND

Human exposure to bisphenol A (BPA) is common. The reproductive toxicity of BPA has been well characterized. However, the impact of BPA exposure on fecundability in healthy women is less clear, and evidence from eastern countries is lacking.

OBJECTIVES

We aimed to prospectively assess the associations of BPA with female fecundability, as measured by time to pregnancy (TTP).

METHODS

From 2013 to 2015, we included 700 Chinese couples attempting pregnancy in two preconception care clinics and followed for 12 months or until a pregnancy occurred. The concentrations of BPA were determined in preconception urine samples of female partners. Cox's proportional models for discrete survival time were used to estimate fecundability odds ratios (FORs). Odds ratios (ORs) for infertility (TTP > 12 months) were estimated using logistic regression models.

RESULTS

After adjusting for potential confounders, each ln-unit increase in urinary concentrations of BPA was associated with a 13% reduction in fecundability (FOR = 0.87; 95% CI: 0.78, 0.98) and a 23% increase in odds of infertility (OR = 1.23; 95% CI: 1.00, 1.50). Women in the highest quartile of urinary BPA had a 30% reduction in fecundability (FOR = 0.70, 95% CI: 0.51, 0.96) and a 64% increase in odds of infertility when compared to those in the lowest quartile (OR = 1.64, 95% CI: 0.90, 2.98). The associations of urinary BPA concentrations with fecundability (FOR = 0.80, 95% CI: 0.67, 0.95) and infertility (OR = 1.43, 95% CI: 1.05, 1.93) were strengthened among women over 30 years of age.

CONCLUSIONS

Our results suggest that preconception concentrations of BPA in female urine were associated with decreased fecundability, particularly among women at older ages. These findings should be confirmed in future human studies.