Preimplantation Exposure to Bisphenol A and Triclosan May Lead to Implantation Failure in Humans

In silico analysis of endocrine-disrupting potential of triclosan, bisphenol A, and their analogs and derivatives

Owning to the increasing body of evidence about the ubiquitous exposure to endocrine disruptors (EDCs), particularly bisphenol A (BPA), and associated health effects, BPA has been gradually substituted with insufficiently tested structural analogs. The unmanaged excessive use of antimicrobial agents such as triclosan (TCS) during the COVID-19 outbreak has also raised concerns about its possible interferences with hormonal functions. The similarity of BPA and estradiol, as well as TCS and non-steroidal estrogens, imply that endocrine-disrupting properties of their analogs could be predicted based on the chemical structure. Hence, this study aimed to evaluate the endocrine-disrupting potential of BPA substitutes as well as TCS derivatives and degradation/biotransformation metabolites, in comparison to BPA and TCS based on their molecular properties, computational predictions of pharmacokinetics and binding affinities to nuclear receptors. Based on the obtained results several under-researched BPA analogs exhibited higher binding affinities for nuclear receptors than BPA. Notable analogs included compounds detected in receipts (DD-70, BTUM-70, TGSA, and BisOPP-A), along with a flame retardant, BDP. The possible health hazards linked to exposure to TCS and its mono-hydroxylated metabolites were also found. Further research is needed in order to elucidate the health impacts of these compounds and promote better regulation practices.

Immune response to foreign materials in spinal fusion surgery

Spinal fusion surgery is a common procedure used to stabilize the spine and treat back pain. The procedure involves the use of foreign materials such as screws, rods, or cages, which can trigger a foreign body reaction, an immune response that involves the activation of immune cells such as macrophages and lymphocytes. The foreign body reaction can impact the success of spinal fusion, as it can interfere with bone growth and fusion. This review article provides an overview of the cellular and molecular events in the foreign body reaction, the impact of the immune response on spinal fusion, and strategies to minimize its impact. By carefully considering the use of foreign materials and optimizing surgical techniques, the impact of the foreign body reaction can be reduced, leading to better outcomes for patients.

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

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

Human Exposure to Bisphenols, Parabens, and Benzophenones, and Its Relationship with the Inflammatory Response: A Systematic Review

Bisphenols, parabens (PBs), and benzophenones (BPs) are widely used environmental chemicals that have been linked to several adverse health effects due to their endocrine disrupting properties. However, the cellular pathways through which these chemicals lead to adverse outcomes in humans are still unclear, suggesting some evidence that inflammation might play a key role. Thus, the aim of this study was to summarize the current evidence on the relationship between human exposure to these chemicals and levels of inflammatory biomarkers. A systematic review of peer-reviewed original research studies published up to February 2023 was conducted using the MEDLINE, Web of Science, and Scopus databases. A total of 20 articles met the inclusion/exclusion criteria. Most of the reviewed studies reported significant associations between any of the selected chemicals (mainly bisphenol A) and some pro-inflammatory biomarkers (including C-reactive protein and interleukin 6, among others). Taken together, this systematic review has identified consistent positive associations between human exposure to some chemicals and levels of pro-inflammatory biomarkers, with very few studies exploring the associations between PBs and/or BPs and inflammation. Therefore, a larger number of studies are required to get a better understanding on the mechanisms of action underlying bisphenols, PBs, and BPs and the critical role that inflammation could play.

Pre-implantation triclosan exposure alters uterine receptivity through affecting tight junction protein†

Triclosan (TCS) is a broad-spectrum antibacterial agent and widely exists in environmental media and organisms. TCS exposure was reported to have adverse effects on reproduction including embryo implantation disorder. During the embryo implantation window, it is vital that the endometrium develops into a receptive state under the influence of ovarian hormones. However, the effect of TCS on embryo implantation and endometrial receptivity remains unclear. In current study, we found decreased embryo implantation rate, serum estrogen (E2) and progesterone (P4) levels in mice exposed to TCS from gestation day (GD) 0.5 to 5.5. Through RNA-seq, we identified nearly 800 differentially expressed genes (DEGs), which were enriched in pathways including uterus development, inflammatory response and immune system process. Among those enriched pathways, the tight junction pathway is essential for the establishment of receptive state of endometrium. Then, genes involved in tight junction pathway including Cldn7, Cldn10 and Crb3 were validated by RT-qPCR and the results were consistent with the RNA-seq. Through immunofluorescence staining and western blotting, we confirmed that the tight junction protein levels of CLDN7 and CRB3 were increased. All these findings suggest that pre-implantation TCS exposure reduces the rate of embryo implantation through up-regulating the expression of tight junction genes and affecting the receptivity of endometrium. Our data could be used to determine the sensitive time frame for TCS exposure and offer new strategy to prevent implantation failure.

Interventions on Reducing Exposure to Endocrine Disrupting Chemicals in Human Health Care Context: A Scoping Review

Purpose

Inevitability of exposure to endocrine disrupting chemicals (EDCs) in daily lives of modern society is increasing interests in developing and implementing interventions to prevent or reduce harmful health effects of EDCs in various academic areas. This is a scoping review of intervention studies aimed at reducing exposure to EDCs in the text of human health care.

Methods

Scoping review methodology was used to explore the extent, range, and nature of current literature. A comprehensive systematic search of PubMed, CINAHL, Cochrane, PcycINFO, EMBASE, and RISS was performed for studies published to date. The authors followed Arksey and O’Malley’s stages; 1) identification of research questions; 2) identification of relevant studies using a total of six electronic databases; 3) study selection; 4) charting the data; and 5) collation, summarization and reporting of the data.

Results

A total of 2114 articles were retrieved, from which 13 articles were included in the final review. Among the 13 studies, 12 conducted interventions regarding dietary modification or replacement of household or personal goods. The duration of interventions ranged from at least three days to a maximum of six months, including six studies with a period of less than ten days. The participants were all healthy populations, eight of which were for adults, three for children or adolescents, and two for families. Outcome of the interventions were measured through concentration of EDCs in urine or/and house air. The effects of the interventions were inconsistent, with 11 studies showing significant changes of EDC concentration while no significant change was found in two studies.

Conclusion

The results indicate a need for randomized controlled trials, participant-centered studies promoting active participation and practices of subjects, studies specifying subgroups of participants, and studies including families as units in interventions.

The Role of Environmental Toxicant-Induced Oxidative Stress in Male Infertility

Infertility is a serious public health issue affecting around 15% of couples globally. Of the 60-80 million people of reproductive age affected by infertility, 40-50% are due to male factor while 30-40% of cases are still idiopathic. The recent global deterioration in sperm quality raises apprehensions regarding the toxic effects of environmental pollutants on reproductive health of males. Environmental toxicants have shown strong evidences for inducing oxidative stress affecting spermatogenesis severely, thereby leading to reduced sperm motility, count, and DNA damage. Reactive oxygen species (ROS) influences the spermatozoa development and transit process both internally and externally. Low level of ROS is indispensable for critical physiological sperm processes like sperm capacitation, motility, acrosome reaction, hyper-activation, sperm-oocyte interaction, etc., while excessive ROS disrupt antioxidant molecules which is detrimental to normal functioning of the sperm. Hence, identification of potential environmental toxicant may have clinical relevance for early screening and diagnosis of male infertility.

Cosmetic and personal care product use, urinary levels of parabens and benzophenones, and risk of endometriosis: results from the EndEA study

AIM

To explore the relationship of urinary concentrations of different congeners of benzophenones and parabens with the utilization of cosmetics and personal care products (PCPs) and their impact on the risk of endometriosis, and to evaluate the influence of oxidative stress on associations found.

METHODS

This case-control study comprised a subsample of 124 women (35 cases; 89 controls). Endometriosis was confirmed (cases) or ruled out (controls) by laparoscopy, with visual inspection of the pelvis and biopsy of suspected lesions (histological diagnosis). Urinary concentrations of benzophenone-1 (BP-1), benzophenone-3 (BP-3), 4-hydroxibenzophenone (4-OH-BP), methyl- (MeP), ethyl- (EtP), propyl- (PrP), and butyl-paraben (BuP), and biomarkers of oxidative stress [lipid peroxidation (TBARS) and total antioxidant power (TAP)] were quantified. Information was gathered on the frequency of use of cosmetics and PCPs. Associations between the frequency of cosmetics/PCP use, urinary concentrations of benzophenones and parabens, oxidative stress, and endometriosis risk were explored in logistic and linear multivariable regression analyses.

RESULTS

The frequency of utilization of certain cosmetics and PCPs was significantly associated with urinary concentrations of benzophenones and parabens. After adjustment for potential confounders, the risk of endometriosis was increased in women in the second versus first terciles of MeP (OR = 5.63; p-value<0.001), BP-1 (OR = 5.12; p-value = 0.011), BP-3 (OR = 4.98; p-value = 0.008), and ƩBPs (OR = 3.34; p-value = 0.032). A close-to-significant relationship was observed between TBARS concentrations and increased endometriosis risk (OR = 1.60, p-value = 0.070) and an inverse association between TAP concentrations and this risk (OR = 0.15; p-value = 0.048). Oxidative stress results did not modify associations observed between benzophenone/paraben exposure and endometriosis risk.

CONCLUSIONS

Our findings indicate that the frequency of cosmetics and PCP utilization is a strong predictor of exposure to certain benzophenone and paraben congeners. These compounds may increase the risk of endometriosis in an oxidative stress-independent manner. Further studies are warranted to corroborate these findings.

Chronic exposure of adult male Wistar rats to bisphenol A causes testicular oxidative stress: Role of gallic acid

OBJECTIVES

Bisphenol A (BPA) has been reported that among other male reproductive dys-functions, it can cause marked estrogenic effects including alteration in serum hormones as well as testicular lesions in exposed animals. This work sought to study the role of gallic acid (GA), a known antioxidant, on the BPA-induced testicular oxidative stress in adult male Wistar rats using serum hormone analysis, histopathology, and biochemical assays.

METHODS

Adult male rats were divided into four groups (n=10) including control (0.2 ml of corn oil), GA (20 mg/kg/day), BPA (10 mg/kg/day), BPA+GA (BPA, 10 mg/kg/day + GA, 20 mg/kg/day). All medications were given by oral gavage for 45 consecutive days. The body and testicular weights were measured. Blood and organ samples were collected for the serum hormonal assay: testosterone (T), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL), and tissue biochemistry analysis: superoxide dismutase (SOD), reduced glutathione (GSH), glutathione-S-transferase (GST), malondialdehyde (MDA), hydrogen peroxide (H2O2), respectively.

RESULTS

The BPA-treated rats showed significant reduction in the gonadosomatic index. BPA also caused significant decrease in the levels of the serum testosterone and prolactin. Furthermore, BPA induced testicular oxidative stress by decreasing the activities of antioxidant enzymes and increasing reactive oxygen species. However, co-treatment with GA protected against these alterations.

CONCLUSION

Findings from the present study confirmed the previously reported data and show that the ability of GA, as a potent antioxidant, may protect against BPA-induced alterations in the male reproductive function. Hence, GA protects against testicular oxidative stress in adult male Wistar rats following chronic exposure to BPA.

Triclosan exposure and in vitro fertilization treatment outcomes in women undergoing in vitro fertilization

Triclosan (TCS) is a widespread environmental endocrine-disrupting chemical. Animal and in vitro studies suggested that triclosan may affect homesostasis of sex and thyroid hormones and impact on reproduction. Due to limited data derived from human epidemiological studies, this study was performed to examine the association between urinary concentration of triclosan and in vitro reproductive outcomes (methaphase II (MII) oocyte yield, top quality embryo, fertilization rate, implantation rate, and clinical pregnancy) among women from infertility clinic. The study participants were enrolled in an Infertility Center in Poland. A total of 450 women aged 25-45 (n = 674 IVF cycles) provided urine samples. The urinary concentrations of triclosan were evaluated using validated gas chromatography ion-tap mass spectrometry method. Clinical outcomes of IVF treatment were abstracted from patients electronic chart records. Triclosan was detected in urine of 82% of women with geometric mean 2.56 ± 6.13 ng/mL. Urinary concentrations of triclosan were associated with decrease implantation rate (p = 0.03). There were no association between other examined IVF outcomes: MII oocytes, embryo quality, fertilization rate, and exposure to triclosan. As this is one of the first study on this topic, studies among larger and more diverse population are needed to confirm the results.

Perinatal exposure to glyphosate or a glyphosate-based formulation disrupts hormonal and uterine milieu during the receptive state in rats

We investigated the effects of perinatal exposure to a glyphosate-based herbicide (GBH) or glyphosate alone (Gly) on female fertility and the hormonal and uterine milieu during the preimplantation period. F0 pregnant rats orally received a GBH or Gly in a dose of 2 mg of glyphosate/kg/day from gestational day (GD) 9 until weaning. F1 females were evaluated to determine the reproductive performance on GD19; and the sex steroid serum levels, the expression of estrogen receptor alpha (ERα), progesterone receptor (PR) and implantation-related genes on GD5 (preimplantation period). GBH and Gly induced preimplantation losses in F1 rats. GBH and Gly groups exhibited higher 17β-estradiol serum levels, without changes in progesterone. Both compounds increased the uterine ERα protein expression, with no differences at transcript level; and only Gly decreased PR mRNA expression. Also, GBH and Gly downregulated Hoxa10 and Lif genes, with no difference in Muc1 and Areg expression. To conclude, perinatal exposure to a GBH or Gly disrupted critical hormonal and uterine molecular targets during the receptive state, possibly associated with the implantation failures. Overall, similar results were found in GBH- and Gly-exposed rats, suggesting that the active principle might be the main responsible for the deleterious effects.

Effect of Triclosan Exposure on Developmental Competence in Parthenogenetic Porcine Embryo during Preimplantation

Triclosan (TCS) is included in various healthcare products because of its antimicrobial activity; therefore, many humans are exposed to TCS daily. While detrimental effects of TCS exposure have been reported in various species and cell types, the effects of TCS exposure on early embryonic development are largely unknown. The aim of this study was to determine if TCS exerts toxic effects during early embryonic development using porcine parthenogenetic embryos in vitro. Porcine parthenogenetic embryos were cultured in in vitro culture medium with 50 or 100 µM TCS for 6 days. Developmental parameters including cleavage and blastocyst formation rates, developmental kinetics, and the number of blastomeres were assessed. To determine the toxic effects of TCS, apoptosis, oxidative stress, and mitochondrial dysfunction were assessed. TCS exposure resulted in a significant decrease in 2-cell rate and blastocyst formation rate, as well as number of blastomeres, but not in the cleavage rate. TCS also increased the number of apoptotic blastomeres and the production of reactive oxygen species. Finally, TCS treatment resulted in a diffuse distribution of mitochondria and decreased the mitochondrial membrane potential. Our results showed that TCS exposure impaired porcine early embryonic development by inducing DNA damage, oxidative stress, and mitochondrial dysfunction.

Exposure of Triclosan in Porcine Oocyte Leads to Superoxide Production and Mitochondrial-Mediated Apoptosis During In Vitro Maturation

While triclosan (TCS) exerts detrimental effects on female reproduction, the effect of TCS-derived toxins on porcine oocytes during in vitro maturation (IVM) is unclear. This study investigated the effects of TCS on mitochondrion-derived reactive oxygen species (ROS) production and apoptosis pathways during porcine oocyte maturation. Porcine oocytes were treated with TCS (1, 10, and 100 μM) and triphenylphosphonium chloride (Mito-TEMPO; 0.1 μM), and matured cumulus oocyte complexes (COCs) were stained with orcein, dichlorofluorescein diacetate (DCF-DA), and Mito-SOX. Proteins and mRNA levels of factors related to cumulus expansion and mitochondrion-mediated apoptosis and antioxidant enzymes were analyzed by western blotting and reverse-transcription polymerase chain reaction (RT-PCR), respectively. Meiotic maturation and cumulus cell expansion significantly decreased for COCs after TCS treatment along with an increase in mitochondrial superoxide levels at 44 h of IVM. Further, mitochondrion-related antioxidant enzymes and apoptosis markers were significantly elevated in porcine COCs following TCS-mediated oxidative damage. The protective effect of Mito-TEMPO as a specific superoxide scavenger from TCS toxin improved the maturation capacity of porcine COCs. Mito-TEMPO downregulated the mitochondrial apoptosis of TCS-exposed porcine COCs by reducing superoxide level. In conclusion, our data demonstrate that TCS mediates toxicity during porcine oocyte maturation through superoxide production and mitochondrion-mediated apoptosis.

Maternal exposure to environmentally relevant doses of bisphenol A causes reproductive dysfunction in F1 adult male rats: protective role of melatonin

This study investigated the protective effects of melatonin (MLT), a potent antioxidant, in male Wistar rats exposed to environmentally relevant doses of bisphenol A (BPA) in utero. Pregnant Wistar rats were randomly assigned into five groups. Group 1 (control) received 0.2 mL 1% dimethyl sulfoxide (DMSO)/99% canola oil as vehicle; group 2 received BPA at 25 μg/kg/day; group 3 received BPA at 250 μg/kg/day; group 4 received BPA at 25 μg/kg/day with concurrent MLT 1 mg/kg/day while group 5 received BPA at 250 μg/kg/day with concurrent MLT 1 mg/kg/day. Treatments were by gavage from gestational day (GD) 10-21. The BPA-treated rats showed dose-dependent significant reduction in body weight, gonosomatic index, sperm motility, livability and count. Also, BPA caused significant reduction in the levels of serum testosterone and luteinizing hormone while it caused significant increases in the levels of follicle stimulating hormone as well as estradiol. Furthermore, BPA induced testicular oxidative stress including significant decreases in the activities of testicular SOD, GSH and GPx as well as GST, increasing the levels of testicular MDA and H2O2. It further induced interstitial necrosis and germinal cell degeneration in the testis with a subsequent diminution of the tubular and luminal diameter. However, co-treatment with MLT offered protection against testicular damage induced by BPA. Melatonin is likely to protect against alterations of the male reproductive system caused by BPA through a direct action on the mechanism of anti-oxidants as well as through the inhibition of necrosis.

Urinary concentration of personal care products and polycystic ovary syndrome: A case-control study

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorder among females of reproductive age. Many emerging contaminants in personal care products have been confirmed with endocrine disruptive effects. We performed a case-control study to explore the association between the concentrations of certain emerging contaminants (organic UV filters, bisphenol A, and triclosan) and the risk of PCOS. Urine samples were collected from 40 women with PCOS (case group) and 83 healthy women (control group). No significant differences were found in detection rate or total concentrations of analytes in women with PCOS and controls (p > 0.05). In addition, no association was found between certain emerging contaminants and PCOS either in an unadjusted binary logistic regression model or in a model adjusted for potential confounders. However, with stratification according to body mass index, one organic UV filter - octocrylene(OC) was significantly associated with PCOS in women with BMI ≥ 24 (adjusted OR = 1.512, 95% CI: 1.043, 2.191). It's the first time to investigate the association between exposure of organic UV filters and PCOS risk. We conclude that there is positive association between OC and PCOS risk in obese and overweight women.

Lycopene reduces in utero bisphenol A exposure-induced mortality, benefits hormones, and development of reproductive organs in offspring mice

This study was conducted to investigate the protective effect of lycopene on reproductive toxicity induced by in utero exposure to bisphenol A (BPA) in offspring mice. Pregnant mice in the BPA model group were given orally 500 mg/kg/day BPA from pregnant day (PD)8 to PD14. Mice of lycopene group were gavaged with 20 mg/kg/day lycopene from PD1 to PD7 and then given 500 mg/kg/day BPA from PD8 to PD14. Results showed that lycopene reduced the elevated mortality in offspring mice of the mother exposed to BPA. BPA lowered the levels of testosterone, luteinizing hormone, and follicle-stimulating hormone while lycopene treatment increased the levels significantly. BPA elevated estradiol while lycopene lowered estradiol in the offspring. BPA caused testicular damage as shown by less Leydig cells and ovarian injury as shown by less corpus granules in adult offspring, while lycopene decreased the damages. Maternal exposure to BPA increased Bax and decreased Bcl-2 in testicular and ovary tissues in the offspring mice. Lycopene decreased Bax in testis and ovary and increased Bcl-2 in ovary tissues in the offspring mice. These findings suggest lycopene has protective effects on in utero BPA exposure-induced reproductive toxicity in offspring mice.

Effects of Bisphenol A and 4-tert-Octylphenol on Embryo Implantation Failure in Mouse

Miscarriage due to blastocyst implantation failure occurs in up to two-thirds of all human miscarriage cases. Calcium ion has been shown to be involved in many cellular signal transduction pathways as well as in the regulation of cell adhesion, which is necessary for the embryo implantation process. Exposure to endocrine-disrupting chemicals (EDs) during early gestation results in disruption of intrauterine implantation and uterine reception, leading to implantation failure. In this study, ovarian estrogen (E2), bisphenol A (BPA), or 4-tert-octylphenol (OP), with or without ICI 182,780 (ICI) were injected subcutaneously from gestation day 1 to gestation day 3 post-coitus. The expression levels of the calcium transport genes were assessed in maternal uteri and implantation sites. The number of implantation sites was significantly low in the OP group, and implantation sites were absent in the E2, ICI and EDs + ICI groups. There were different calcium transient transport channel expression levels in uterus and implantation site samples. The levels of TRPV5 and TRPV6 gene expression were significantly increased by EDs with/without ICI treatment in utero. Meanwhile, TRPV5 and TRPV6 gene expression were significantly lower in implantation sites samples. NCX1 and PMCA1 mRNA levels were significantly decreased by OP and BPA in the implantation site samples. Compared to vehicle treatment in the uterus, both the MUC1 mRNA and protein levels were markedly high in all but the BPA group. Taken together, these results suggest that both BPA and OP can impair embryo implantation through alteration of calcium transport gene expressions and by affecting uterine receptivity.

Vulnerability of marsh frog Pelophylax ridibundus to the typical wastewater effluents ibuprofen, triclosan and estrone, detected by multi-biomarker approach

Pharmaceutical and personal care products (PPCPs) are the environmental pollutants of growing concern. The aim of this study was to indicate the effects of typical PPCPs on the marsh frog Pelophylax ridibundus. We treated male frogs with waterborne ibuprofen (IBU, 250ng·L^-1), triclosan (TCS, 500ng·L^-1), or estrone (E1, 100ng·L^-1) for 14days. Common vulnerability of the frogs was detected from dramatic decrease of Zn, total and metalated metallothionein (MT) concentrations, Zn/Cu ratio, the elevation of activity of glutathione-S-transferase, cathepsin D and DNA instability in the liver, the depletion of cholinesterase in the brain and cortisol in the blood plasma in all exposures. Nevertheless, lipofuscin concentration in the liver was always decreased. The groups were best distinguished by cytochrome P450 (CYP450) activity determined by ELISA. The exposure to IBU caused lesser damage, but elevated the levels of oxyradicals and glutathione (GSH and GSSG) and lysosomal membrane instability. Exposures to TCS and E1 provoked the endocrine disturbance (increased levels of vitellogenin and thyrotropin in blood plasma), decreased lactate dehydrogenase activity and increased level of pyruvate in the liver. TCS caused the increase of GSSG by 7.3 times and lactate levels. Only E1 lead to decrease of deiodinase activity in the liver, activation of CYP450 and caspase-3 and efflux of cathepsin D from lysosomes. Spectrophotometric and ELISA assays of MTs and CYP450 gave distinct results in E1-group. Broad disruption of the hormonal pathways caused by E1 could be of concern for the health status of frogs in their habitats.

Urinary triclosan concentrations and early outcomes of in vitro fertilization-embryo transfer

Triclosan (TCS) exists ubiquitously in the environment. Several in vitro and in vivo studies have demonstrated that TCS exerts endocrine disruptive effects on reproduction, but data from human populations are limited and conflicting. The objective of our study was to investigate whether high urinary TCS concentration is adversely associated with early reproductive outcomes in women undergoing in vitro fertilization-embryo transfer (IVF-ET). This prospective cohort study was conducted from September 2015 to June 2016, including 156 infertile women undergoing their first IVF-ET cycle. Two spot urine samples were collected prior to oocyte retrieval for TCS detection using solid-phase extraction (SPE) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Linear regression model and binary logistic regression model were used to evaluate the association between urinary TCS concentrations and IVF outcomes. The intake of aquaculture food may have positive influences on urinary TCS concentrations. After adjustment for age, body mass index (BMI), baseline follicle-stimulating hormone (FSH), antral follicle count (AFC) and smoking status, a significant decrease of top quality embryo formation and implantation rate was observed in patients with urinary TCS concentration greater than or equal to the median level (0.045 μmol/mol Cr). We concluded that TCS exposure may exert negative effects during early stages of human reproduction.

Health behaviors related to endocrine-disrupting chemicals and the associated factors of adolescent Korean girls

In this cross-sectional study, we examined the relationships among knowledge about endocrine-disrupting chemicals (EDCs), recognition of EDCs-related female reproductive illnesses, concern for the environment, perceived susceptibility to EDCs-related diseases, self- appraisal of exposure to EDCs, and health behaviors related to EDCs in adolescent Korean girls. A convenience sample of 218 girls was recruited during July and August 2015 from middle and high schools located in a city in Korea. The self-administered questionnaire incorporated four characteristics of the participants, five related factors, and a dependent variable of health behaviors. Four of the factors explained 20.4 percent of variance in health behaviors, and after controlling covariates, concern for the environment and self-appraisal of exposure to EDCs were still significant factors explaining 29.0 percent of the variance in health behaviors. However, for one factor, knowledge about EDCs, no independent contribution to health behaviors was observed. The findings indicated that education for young women should focus on enhancing their interests in the environment and awareness of environmental hazards. Further, clear and reliable guidelines to protect young women from the exposure to EDCs should be provided to adolescent girls.

Environmental Contaminants Affecting Fertility and Somatic Health

This review article summarizes the epidemiological findings published between 2011 and 2016 concerning bisphenol A (BPA), phthalates, dioxins, pesticides, air pollution, fracking chemicals, triclosan, and parabens and fertility parameters in men (i.e., semen volume, sperm concentration, sperm motility, and sperm morphology) as well as fertility parameters in women (i.e., cyclicity, fertility treatment outcomes), pregnancy outcomes (i.e., preterm birth, miscarriage), and reproductive disorders (i.e., polycystic ovary syndrome, endometriosis, and uterine fibroids). Overall, this review indicates that several environmental toxicants are significantly associated with reduced fertility parameters in men and women as well as several reproductive disorders in women. Although many studies reported that the selected exposures are associated with adverse fertility outcomes, several studies reported null associations. Thus, future studies are still needed to better elucidate the associations and potential mechanisms between these environmental chemicals and fertility outcomes in men and women.

Bisphenol A Exposure during Pregnancy Alters the Mortality and Levels of Reproductive Hormones and Genes in Offspring Mice

The present study investigated the reproductive toxicity of bisphenol A (BPA) exposure to the mother on the offspring mice. BPA was given to pregnant mice at 50 mg/kg, 500 mg/kg, and 2500 mg/kg BW BPA daily by gavage during the whole gestation period. The offspring mice were sacrificed at 8 weeks of age. Results showed that exposure of BPA to the mother increased the mortality (P < 0.05). Maternal exposure of BPA reduced the levels of T (♂) and FSH (♀) (P < 0.01) and elevated E₂ (♀) level in the adult offspring (P < 0.01). BPA exposure caused testicular damage as shown by less Leydig cells and ovarian injury as shown by more vacuoles and less corpus granules in the adult offspring mice. Immunohistochemistry revealed that maternal exposure of BPA increased Bax and decreased Bcl-2 at the protein levels in testicular and ovary tissues in the offspring mice. BPA significantly reduced the expression of StAR in male offspring (P < 0.05). Interestingly, the mRNA levels of Cyp11a were significantly decreased in 50 mg/kg groups and were increased in 500 mg/kg group in the males. Reduced Kitlg and elevated Amh at the mRNA levels were detected in the female offspring.