Efficient remediation of di-(2-ethylhexyl) phthalate and plant-growth promotion with the application of a phosphate-solubilizing compound microbial agent

The ecotoxic endocrine-disrupting chemical di-(2-ethylhexyl) phthalate (DEHP) is ubiquitous in agricultural soil, posing a serious threat to human health. Here, we report efficient soil-borne DEHP degradation and plant growth promotion by a microbial organic fertilizer GK-PPB prepared by combining a recycled garden waste-kitchen waste compost product with ternary compound microbial agent PPB-MA, composed of Penicillium oxalic MB08F, Pseudomonas simiae MB751, and Bacillus tequilensis MB05B. The combination of MB08F and MB751 provided synergistic phosphorus solubilization, and MB05B enhanced the DEHP degradation capacity of MB08F via bioemulsification. Under optimal conditions (25.70 °C and pH 7.62), PPB-MA achieved a 96.81 % degradation percentage for 1000 mg L-1 DEHP within 5 days. The degradation curve followed first-order kinetics with a half-life of 18.24 to 24.76 h. A complete mineralization pathway was constructed after identifying the degradation intermediates of 2H-labeled DEHP. Evaluation in Caenorhabditis elegans N2 showed that PPB-MA eliminated the ecological toxicity of DEHP. A pakchoi (Brassica chinensis L.) pot experiment demonstrated that GK-PPB promoted phosphorus solubilization and plant growth, reduced soil DEHP residue, and decreased DEHP accumulation in pakchoi, suggesting its potential practical utility in environmentally responsible and safe cultivation of vegetables.

Environmental bisphenol A disrupts methylation of steroidogenic genes in the ovary of Paradise threadfin Polynemus paradiseus via abnormal DNA methylation: Implications for human exposure and health risk assessment

Bisphenol A, endocrine-disrupting chemicals (EDCs) impacting disease development via epigenetic modifications, is crucial in transcriptional regulation. However, ecotoxicology's limited exploration of epigenetics prompted our study's objective: examining the extended exposure of riverine Bisphenol A (BPA), a potent EDC, on DNA methylation during female paradise threadfin (Polynemus paradiseus) reproductive maturation. Assessing BPA contamination in riverine water, we collected fish samples from two locations with distinct contamination levels. In the highly contaminated region (Hc), we observed elevated DNA methylation in aromatase (7.5-fold), 20β-HSD (3-fold), and FSHR (2-fold) genes. Hormone receptor investigation highlighted an escalating connection between transcriptional hyper-methylation and contamination levels. Additionally, our study revealed a positive correlation between oocyte growth and global DNA methylation, suggesting BPA's potential to modify DNA methylation in female paradise threadfins. This effect likely occurs through changes in hormone receptor expression, persisting throughout oocyte maturation. Notably, our research, the first of its kind in estuarine areas, confirmed BPA contamination in paradise threadfins, raising concerns about potential health risks for humans.

Diisobutyl phthalate (DiBP)-induced male germ cell toxicity and its alleviation approach

Diisobutyl phthalate (DiBP) is a commonly used plasticizer in manufacturing consumer and industrial products to improve flexibility and durability. Despite of the numerous studies, however, the direct mechanism underlying the male reproductive damage of DiBP is poorly understood. In this study, we investigated the male germ cell toxicity of DiBP using GC-1 spermatogonia (spg) cells. Our results indicated that DiBP exposure causes oxidative stress and apoptosis in GC-1 spg cells. In addition, DiBP-derived autophagy activation and down-regulation of phosphoinositide 3-kinase (PI3K)-AKT and extracellular signal-regulated kinase (ERK) pathways further inhibited GC-1 spg cell proliferation, indicating that DiBP can instigate male germ cell toxicity by targeting several pathways. Importantly, a combined treatment of parthenolide, N-acetylcysteine, and 3-methyladenine significantly reduced DiBP-induced male germ cell toxicity and restored proliferation. Taken together, the results of this study can provide valuable information to the existing literature by enhancing the understanding of single phthalate DiBP-derived male germ cell toxicity and the therapeutic interventions that can mitigate DiBP damage.

The mixed effect of Endocrine-Disrupting chemicals on biological age Acceleration: Unveiling the mechanism and potential intervention target

INTRODUCTION

Although previous studies investigated the potential adverse effects of endocrine-disrupting chemicals (EDCs) on biological age acceleration and aging-related diseases, the mixed effect of multiple types of EDCs on biological age acceleration, including its potential underlying mechanism, remains unclear.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) were used to analyze biological age measures, including Klemera-Doubal method biological age (KDM-BA), phenotypic age, and homeostatic dysregulation (HD). Weight quantile sum (WQS) regression was performed to screen biological age-related EDCs (BA-EDCs) and assess the mixed effect of BA-EDCs on biological age acceleration and aging-related disease. Targets of BA-EDCs were obtained from three databases, while heart aging-related genes were obtained from the Aging Anno database. Protein-protein interaction (PPI) network and MCODE algorithm were applied to identify potential interactions between BA-EDC targets and heart aging-related genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed to identify related pathways.

RESULTS

This cross-sectional study included 1,439 participants. A decile increase in BA-EDCs co-exposure was associated with 0.31 years and 0.17 years of KDM-BA and phenotypic age acceleration, respectively. The mixed effect of BA-EDCs was associated with an increased prevalence of atherosclerotic cardiovascular disease (ASCVD). Vitamins C and E demonstrated a significant interaction effect on the association between BA-EDCs and KDM-BA acceleration. PPI network and functional enrichment analysis indicated that the AGE-RAGE signaling pathway in diabetic complications was significantly enriched.

CONCLUSION

Our results showed that the co-exposure effect of BA-EDCs was associated with biological age acceleration and ASCVD, with the AGE-RAGE signaling pathway being the underlying mechanism. Vitamins C and E may also be an actionable target for preventing EDC-induced biological aging.

Pubertal glyphosate-based herbicide exposure aggravates high-fat diet-induced obesity in female mice

Glyphosate-based herbicides (GBH) are the most widely used pesticides globally. Studies have indicated that they may increase the risk of various organic dysfunctions. Herein, we verified whether exposure to GBH during puberty increases the susceptibility of male and female mice to obesity when they are fed a high-fat diet (HFD) in adulthood. From the 4th-7th weeks of age, male and female C57Bl/6 mice received water (CTL group) or 50 mg GBH /kg body weight (BW; GBH group). From the 8th-21st weeks of age, the mice were fed a standard diet or a HFD. It was found that pubertal GBH exposure exacerbated BW gains and hyperphagia induced by HFD, but only in female GBH-HFD mice. These female mice also exhibited high accumulation of perigonadal and subcutaneous fat, as well as reduced lean body mass. Both male and female GBH-HFD displayed hypertrophic white adipocytes. However, only in females, pubertal GBH exposure aggravated HFD-induced fat accumulation in brown adipocytes. Furthermore, GBH increased plasma cortisol levels by 80% in GBH-HFD males, and 180% in GBH-HFD females. In conclusion, pubertal GBH exposure aggravated HFD-induced obesity, particularly in adult female mice. This study provides novel evidence that GBH misprograms lipid metabolism, accelerating the development of obesity when individuals are challenged by a second metabolic stressor, such as an obesogenic diet.

Application of compost assisted by Fe3O4 nanoparticles in di (2-ethylhexyl) phthalate-contaminated soil remediation: Biostimulation strategy, Soil responses, and RSM/CCD Optimization

Globally, contamination of agricultural soils by phthalate esters (PAEs) caused by direct consumption of plastic mulch films has been confirmed. The most widely used plasticizer is di (2-ethylhexyl) phthalate (DEHP), which is a more recalcitrant endocrine-disrupting chemical (EDC). Because of its low solubility and hydrophobicity, it remains in the soil longer, causes bioaccumulation in agricultural products, and has negative repercussions for food safety. In this study, the performance of kitchen organic waste compost assisted by Fe3O4 nanoparticles in DEHP removal efficiency (%) and soil C:N ratio (two responses) was optimized using Response Surface Methodology (RSM) based on Central Composite Design (CCD) in Design-Expert software (11.0.3.0). Under optimum conditions, a DEHP concentration of 10 mg·kg-1 (dw soil), a retention time of 35 days, an NPs dose of 0.99 g·kg-1 (media), a removal efficiency of 91.6 %, and a soil C:N ratio of 10.5 with a desirability of 0.963 were determined. A quadratic model (P-value <0.0001, adjusted R2 = 0.974 (Y1), 0.943 (Y2)) was used to predict the variables and their interactions. The agricultural soil responses in the treatments amended by compost and Fe3O4 NPs (SCN) showed a significant increase in SOM, TC, TN, AP, K, and Fe nutrients when compared to the control (P < 0.05). After 35 days, in the SC1N3 treatment (DEHP concentration = 10 mg·kg-1, NPs dose =1.2 g·kg-1), with higher DEHP removal efficiency (89.57 %), the C:N:P ratio was equal to 100: 9.75:0.69, and the total microbial colony count was 3.6 × 109 CFU/ml at pH 7.45. The study found that compost nutrients and Fe-based nanoparticle micronutrients can enhance DEHP degradation by stimulating the soil's native microflora. As a result, the synergistic potential of compost and Fe3O4 nanoparticles can be considered a promising, cost-effective, and agri-environmentally friendly approach in the "assisted bioremediation" strategy of DEHP-contaminated soils.

Pregnancy-related maternal physiological adaptations and fetal chemical exposure

Prenatal life represents a susceptible window of development during which chemical exposures can permanently alter fetal development, leading to an increased likelihood of disease later in life. Therefore, it is essential to assess exposure in the fetus. However, direct assessment in human fetuses is challenging, so most research measures maternal exposure. Pregnancy induces a range of significant physiological changes in women that may affect chemical metabolism and responses. Moreover, placental function, fetal sex, and pregnancy complications may further modify these exposures. The purpose of this narrative review is to give an overview of major pregnancy-related physiological changes, including placental function and impacts of pregnancy complications, to summarize existing studies assessing chemical exposure in human fetal organs, and to discuss possible interactions between physiological changes and exposures. Our review reveals major knowledge gaps in factors affecting fetal chemical exposure, highlighting the need to develop more sophisticated tools for chemical health risk assessment in fetuses.

Dietary exposure to an environmentally relevant phthalate mixture alters follicle dynamics, hormone levels, ovarian gene expression, and pituitary gene expression in female mice

Phthalates are chemicals ubiquitously used in industry. Individual phthalates have been found to adversely affect female reproduction; however, humans are exposed to a mixture of phthalates daily, primarily through ingestion. Previous studies show that exposure to an environmentally relevant mixture of phthalates (Mix) can affect female reproduction. Little research, however, has been conducted on the effects of short-term (1 month) and long-term (6 months) exposure to Mix on ovarian functions. Thus, this study tested the hypothesis that short-term and long-term exposure to Mix alters ovarian folliculogenesis, serum hormone concentrations, pituitary gene expression, and ovarian expression of genes involved in steroidogenesis, apoptosis, cell cycle regulation, and oxidative stress. Adult CD-1 female mice were exposed to vehicle control (corn oil) or Mix (0.15-1500 ppm) in the chow for 1 or 6 months. Exposure to Mix for 1 month increased the number of atretic follicles (0.15 ppm), altered ovarian gene expression (0.15 ppm, 1500 ppm), and decreased serum testosterone (1.5 ppm) compared to control. Exposure to Mix for 6 months increased serum follicle-stimulating hormone (FSH) (0.15 ppm), decreased serum luteinizing hormone (LH) (0.15 ppm, 1.5 ppm, and 1500 ppm), decreased serum estradiol (1500 ppm), altered pituitary gene expression (1500 ppm), increased the number (1500 ppm) and percentage (1.5 ppm and 1500 ppm) of primordial follicles, and decreased the percentage of preantral (1500 ppm) and antral (1.5 ppm and 1500 ppm) follicles compared to control. These data indicate that exposure to Mix can alter folliculogenesis, steroidogenesis, and gene expression in female mice.

Effects of bisphenol A on murine salivary glands and human tumor cell lines

Bisphenol A (BPA) is an endocrine-disrupting chemical with a potential role in endocrine cancers. However, the effects of BPA on the salivary glands have been barely explored. We investigated the impact of in vivo sub-chronic exposure to BPA and its in vitro effects on human salivary gland mucoepidermoid carcinoma cell lines. Male and female mice were exposed to BPA (30 mg/kg/day). Sublingual and submandibular salivary glands from an estrogen-deficiency model were also analyzed. BPA concentration in salivary glands was evaluated by gas chromatography coupled to ion trap mass spectrometry. Immunohistochemical analysis using anti-p63 and anti-α-SMA antibodies was performed on mouse salivary gland tissues. Gene expression of estrogen receptors alpha and beta, P63 and α-SMA was quantified in mouse salivary gland and/or mucoepidermoid (UM-HMC-1 and UM-HMC-3A) cell lines. Cell viability, p63 and Ki-67 immunostaining were evaluated in vitro. BPA disrupted the tissue architecture of the submandibular and sublingual glands, particularly in female mice, and increased the expression of estrogen receptors and p63, effects that were accompanied by significant BPA accumulation in these tissues. Conversely, ovariectomy slightly impacted BPA-induced morphological changes. In vitro, BPA did not affect the proliferation of neoplastic cells, but augmented the expression of p63 and estrogen receptors. The present data highlight a potential harmful effect of BPA on salivary gland tissues, particularly in female mice, and salivary gland tumor cells. Our findings suggest that estrogen-dependent pathways may orchestrate the effects of BPA in salivary glands.

Bu-Shen-Tian-Jing formulas alleviate the mitochondrial damage induced by oxidative stress in ovarian granulosa cells exposed to DEHP through the HDAC3-HSP90AA pathway

CONTEXT

di-(2-Ethylhexyl) phthalate (DEHP) has potential reproductive toxicity. Bu-Shen-Tian-Jing formulations (BSTJFs) are beneficial for female reproductive capacity. However, BSTJF2 has much lower cytotoxicity than BSTJF1.

OBJECTIVE

To investigate the effects of BSTJFs on ovarian granulosa cells exposed to DEHP and determine the potential molecular mechanisms.

METHODS AND MATERIALS

Human granulosa-like tumor cell line (KGN) cells were divided into control, DEHP, BSTJF1 and BSTJF2 groups. The DEHP group were given 1 μM DEHP for 24 h. They were then given BSTJF1 at 200 μg/mL or BSTJF2 at 100 μg/mL for 24 h. The control group was treated with the same concentration of DMSO (0.1%). Oxidative stress and mitochondrial function were measured. The mRNA and protein expression levels of HDAC3 and HSP90AA were determined. Integrative network pharmacology analysis of BSTJF2 was also performed.

RESULTS

DEHP (1 μM) significantly suppressed the proliferation of KGN cells by 17%, significantly increased ROS levels by 28% and MDA levels by 47%, significantly decreased MMP levels by 22% and mtDNA copy by 30%. DEHP significantly increased protein expression of HDAC3 by 21%and HSP90AA by 64%. All these changes were significantly reversed by BSTJFs. Integrative network pharmacology analysis revealed HSP90AA was a key target (degree = 8). Both RGFP966 and BSTJF2 significantly reversed the increased expression of HDAC3 and HSP90AA, attenuated oxidative stress, and mitochondrial damage which were induced by DEHP.

CONCLUSION

BSTJFs might have therapeutic potential on oxidative stress and mitochondrial damage through the HDAC3/HSP90AA pathway which encourages further clinical trials.

Occurrence, placental transfer, and health risks of emerging endocrine-disrupting chemicals in pregnant women

Previous studies demonstrated that many environmental chemicals can cross the human placental barrier. However, the risk regarding gestational exposure of emerging endocrine-disrupting chemicals (EDCs) is unclear. In this study, the occurrence of 24 EDCs, such as bisphenol A analogs, parabens, triclocarban, and triclosan, was investigated in serum and urine samples from Chinese pregnant women. Some metabolites were determined in matched serum-urine pairs (n = 75) to perform a comprehensive assessment of exposure. The placental transfer efficiency (PTE) of the detected chemicals was determined in matched maternal-cord serum pairs (n = 110). The mean PTEs of the chemicals showed a large variation from 43.1% to 171.0%. The potential effects of physicochemical properties, molecular structures, and biological factors on PTE were investigated using multiple linear regression models and molecular docking. We found that the PTE of methyl paraben, ethyl paraben, and propyl paraben was associated with their increasing alkyl chain lengths. Furthermore, a comprehensive exposure assessment of EDCs showed that 62.7% of pregnant women had a health index > 1, which indicted potential health risks during pregnancy. However, toxicity and the underlying mechanisms of these EDCs remain to be further studied.

Effects of postnatal exposure to phthalate, bisphenol a, triclosan, parabens, and per- and poly-fluoroalkyl substances on maternal postpartum depression and infant neurodevelopment: a korean mother-infant pair cohort study

Exposure to endocrine-disrupting chemicals (EDCs) can promote infant neurodevelopmental impairment and maternal postpartum depression (PPD). However, the associations between lactation exposure to EDCs, maternal PPD, and infant neurodevelopment are unclear. Hence, we investigated these relationships in infants aged 36-42 months. We recruited 221 Korean mothers and analyzed 29 EDCs. The Edinburgh Postnatal Depression Scale (EPDS) was used to assess maternal PPD. Bayley scales of infant development; the Swanson, Nolan, and Pelham rating scale (SNAP); and the Child Behavior Checklist (CBCL) were used to assess neurodevelopment in infants exposed to the top 30% of EDC over three years. Multiple regression analyses were adjusted for maternal age, pre-pregnancy body mass index, education, income, employment, residence, and infant age and sex. The rates of infants with clinically abnormal diagnoses on neurologic developmental tests (Balyey, SNAP, and CBCL scales) ranged from 7.7 to 38.5% in this study, with the motor and hyperactivity/impulsivity areas scoring the highest among 65 boys and girls. Mono-2-ethylhexyl phthalate (MEHP) and mono-isononyl phthalate (MiNP) levels in breast milk significantly correlated with infant inattention and hyperactivity. Perfluorononanoic acid (PFNA) and perfluorooctyl sulfonate (PFOS) levels correlated significantly with motor development of BSID-III and total CBCL score which mean infant might have lower developmental status. EDC concentrations in breast milk were not associated with maternal PPD. Overall, lactational exposure to EDCs during the postpartum period can exert a negative effect on maternal PPD and infant neurodevelopment.

Environmentally relevant doses of endocrine disrupting chemicals affect male fertility by interfering with sertoli cell glucose metabolism in mice

The growing global deterioration in several aspects of human health has been partly attributed to hazardous effects of endocrine-disrupting chemicals (EDCs) exposure. Therefore, experts and government regulatory agencies have consistently advocated for studies on the combined effects of EDCs that model human exposure to multiple environmental chemicals in real life. Here, we investigated how low concentrations of bisphenol A (BPA), and phthalates compounds affect the Sertoli cell glucose uptake/lactate production in the testis and male fertility. An EDC mixture containing a detected amount of each chemical compound in humans, called daily exposure (DE), and DE increased in magnitude by 25 (DE25), 250 (DE250), and 2500 (DE2500), and corn oil (control) were administered for six weeks to male mice. We found that DE activated estrogen receptor beta (Erβ) and glucose-regulated protein 78 (Grp 78) and disrupted the estradiol (E2) balance. In addition, DE25, DE250, and DE2500 doses of the EDC mixture via binding with Sertoli cells' estrogen receptors (ERs) inhibited the glucose uptake and lactate production processes by downregulating glucose transporters (GLUTs) and glycolytic enzymes. As a result, endoplasmic reticulum stress (ERS), marked by unfolded protein response (UPR) activation, was induced. The accompanying upregulation of activating transcription factor 4 (ATF4), inositol requiring enzyme-1 (IRE1), C/EBP homologous protein (CHOP), and mitogen-activated protein kinase (MAPK) signaling promoted antioxidant depletion, testicular cell apoptosis, abnormal regulation of the blood-testis barrier, and decreased sperm count. Therefore, these findings suggest that human and wildlife exposure to multiple environmental chemicals can produce a wide range of reproductive health complications in male mammals.

Persistent immunosuppressive effects of dibutyl phthalate exposure in adult male mice

Increased exposure to manmade chemicals may be linked to an increase in immune-related diseases in humans and immune system dysfunction in wildlife. Phthalates are a group of endocrine-disrupting chemicals (EDCs) suspected to influence the immune system. The aim of this study was to characterize the persistent effects on leukocytes in the blood and spleen, as well as plasma cytokine and growth factor levels, one week after the end of five weeks of oral treatment with dibutyl phthalate (DBP; 10 or 100 mg/kg/d) in adult male mice. Flow cytometry analysis of the blood revealed that DBP exposure decreased the total leukocyte count, classical monocyte and T helper (Th) populations, whereas it increased the non-classical monocyte population compared to the vehicle control (corn oil). Immunofluorescence analysis of the spleen showed increased CD11b⁺Ly6G⁺ (marker of polymorphonuclear myeloid-derived suppressor cells; PMN-MDSCs), and CD43⁺staining (marker of non-classical monocytes), whereas CD3⁺ (marker of total T cells) and CD4⁺ (marker of Th cells) staining decreased. To investigate the mechanisms of action, levels of plasma cytokines and chemokines were measured using multiplexed immunoassays and other key factors were analyzed using western blotting. The observed increase in M-CSF levels and the activation of STAT3 may promote PMN-MDSC expansion and activity. Increased ARG1, NOX2 (gp91phox), and protein nitrotyrosine levels, as well as GCN2 and phosphor-eIRFα, suggest that oxidative stress and lymphocyte arrest drive the lymphocyte suppression caused by PMN-MDSCs. The plasma levels of IL-21 (promotes the differentiation of Th cells) and MCP-1 (regulates migration and infiltration of monocytes/macrophages) also decreased. These findings show that adult DBP exposure can cause persistent immunosuppressive effects, which may increase susceptibility to infections, cancers, and immune diseases, and decrease vaccine efficacy.

Evaluation of the bisphenol A-induced vascular toxicity on human umbilical artery

Bisphenol A (BPA) is one of the most widely used synthetic compound in the manufacture of polycarbonate plastics and epoxy resins. Worryingly, BPA is an endocrine disrupting chemical (EDC) with an estrogenic, androgenic, or anti-androgenic activities. However, the vascular implications of BPA exposome in pregnancy is unclear. In this sense, the present work proposed to understand how BPA exposure impair the vasculature of the pregnant women. To elucidate this, ex vivo studies were performed using human umbilical arteries to explore the acute and chronic effects of BPA. The mode of action of BPA was also explored by analysing the activity (by ex vivo studies) and expression (in vitro studies) analysis of Ca²⁺ and K⁺-channels and soluble guanyl cyclase. Moreover, in silico docking simulations were performed to unveil the modes of interactions of BPA with the proteins involved in these signalling pathways. Our study showed that the exposure to BPA may modify the vasorelaxant response of HUA, interfering with NO/sGC/cGMP/PKG pathway by modulation of sGC and activation of BKCa channels. Moreover, our findings suggest that BPA can modulate the HUA reactivity, increasing the L-type Ca²⁺ Channels (LTCC) activity, a common vascular response observed in hypertensive disorders of pregnancy.

Investigation of autism-related transcription factors underlying sex differences in the effects of bisphenol A on transcriptome profiles and synaptogenesis in the offspring hippocampus

BACKGROUND

Bisphenol A (BPA) has been linked to susceptibility to autism spectrum disorder (ASD). Our recent studies have shown that prenatal BPA exposure disrupted ASD-related gene expression in the hippocampus, neurological functions, and behaviors associated with ASD in a sex-specific pattern. However, the molecular mechanisms underlying the effects of BPA are still unclear.

METHODS

Transcriptome data mining and molecular docking analyses were performed to identify ASD-related transcription factors (TFs) and their target genes underlying the sex-specific effects of prenatal BPA exposure. Gene ontology analysis was conducted to predict biological functions associated with these genes. The expression levels of ASD-related TFs and targets in the hippocampus of rat pups prenatally exposed to BPA were measured using qRT-PCR analysis. The role of the androgen receptor (AR) in BPA-mediated regulation of ASD candidate genes was investigated using a human neuronal cell line stably transfected with AR-expression or control plasmid. Synaptogenesis, which is a function associated with genes transcriptionally regulated by ASD-related TFs, was assessed using primary hippocampal neurons isolated from male and female rat pups prenatally exposed to BPA.

RESULTS

We found that there was a sex difference in ASD-related TFs underlying the effects of prenatal BPA exposure on the transcriptome profiles of the offspring hippocampus. In addition to the known BPA targets AR and ESR1, BPA could directly interact with novel targets (i.e., KDM5B, SMAD4, and TCF7L2). The targets of these TFs were also associated with ASD. Prenatal BPA exposure disrupted the expression of ASD-related TFs and targets in the offspring hippocampus in a sex-dependent manner. Moreover, AR was involved in the BPA-mediated dysregulation of AUTS2, KMT2C, and SMARCC2. Prenatal BPA exposure altered synaptogenesis by increasing synaptic protein levels in males but not in females, but the number of excitatory synapses was increased in female primary neurons only.

CONCLUSIONS

Our findings suggest that AR and other ASD-related TFs are involved in sex differences in the effects of prenatal BPA exposure on transcriptome profiles and synaptogenesis in the offspring hippocampus. These TFs may play an essential role in an increased ASD susceptibility associated with endocrine-disrupting chemicals, particularly BPA, and the male bias of ASD.

Bisphenol A alters sexual dimorphism and gene expression in marine medaka Oryzias melastigma

Bisphenol A (BPA) is an endocrine disruptor that is present in freshwater and marine environments. However, conclusive evidence for the toxicity of chronic BPA exposure to marine fishes remains lacking. Therefore, we investigated the influence of BPA on male marine medaka (Oryzias melastigma). BPA exposure induced formation of testis-ova at 2610 µg/L, and male-type anal fins became more female type in a concentration-dependent manner. Some males with female-type anal fins had normal testes, indicating that anal fin shape is more sensitive to BPA. Gonadal soma-derived factor (gsdf) expression decreased after BPA exposure in the 746 and 2610 µg/L exposure groups, although the changes were not statistically significant. Additionally, liver vitellogenin (vtg) expression increased in a dose-dependent manner and was significantly higher in all exposure groups. vtg and gsdf are likely to be useful biomarkers for the impact of estrogenic endocrine disrupters in O. melastigma.

UV-B filter octylmethoxycinnamate-induced vascular endothelial disruption on rat aorta: In silico and in vitro approach

Throughout human life, an extensive and varied range of emerging environmental contaminants, called endocrine disruptors (EDCs), cause adverse health effects, including in the cardiovascular (CV) system. Cardiovascular diseases (CVD) are worryingly one of the leading causes of all mortality and mobility worldwide. The UV-B filter octylmethoxycinnamate (also designated octinoxate, or ethylhexyl methoxycinnamate (CAS number: 5466-77-3)) is an EDC widely present in all personal care products. However, to date, there are no studies evaluating the OMC-induced effects on vasculature using animal models to improve human cardiovascular health. This work analysed the effects of OMC on rat aorta vasculature and explored the modes of action implicated in these effects. Our results indicated that OMC relaxes the rat aorta by endothelium-dependent mechanisms through the signaling pathways of cyclic nucleotides and by endothelium-independent mechanisms involving inhibition of L-Type voltage-operated Ca²⁺ channels (L-Type VOCC). Overall, OMC toxicity on rat aorta may produce hypotension via vasodilation due to excessive NO release and blockade of L-Type VOCC. Moreover, the OMC-induced endothelial dysfunction may also occur by promoting the endothelial release of endothelin-1. Therefore, our findings demonstrate that exposure to OMC alters the reactivity of the rat aorta and highlight that long-term OMC exposure may increase the risk of human CV diseases.

Long-term exposure to bisphenol A and its analogues alters the behavior of marine medaka (Oryzias melastigma) and causes hepatic injury

Bisphenols (BPA, BPF, and BPAF) are widely present in the aquatic environment and have various adverse effects on aquatic organisms. However, their hepatic toxicity in marine fish is not fully understood. Hence, we examined the growth parameters, histological features, antioxidant defense mechanisms, and gene expression profiles in the livers of marine medaka after exposure to single and combined bisphenols for 70 days. The final body weight and final body length of males exposed to BPAF were significantly higher than those in the control group, and the survival rate was significantly lower. Bisphenol exposure led to vacuolization and local lesions in the liver, especially in the BPAF group, and altered antioxidant enzyme activity in the liver, leading to oxidative stress. In addition, after bisphenol exposure, marine medaka showed anxiolytic effects and a significant reduction in swimming distance compared with that in the control group. As determined by RNA-seq, bisphenol exposure altered multiple biological pathways in the liver, such as fatty acid biosynthesis, fatty acid metabolism, and ribosome biogenesis pathways, with significant changes in gene expression levels. In particular, chgs and vtgs were significantly up-regulated after BPAF exposure, suggesting an estrogenic effect. Overall, bisphenols can adversely affect the growth and metabolism of marine medaka. BPF and BPAF may not be ideal substitutes for BPA.

Adsorptive removal of synthetic plastic components bisphenol-A and solvent black-3 dye from single and binary solutions using pristine pinecone biochar

The existing study deals with adsorptive removal of the endocrine-disrupting chemical bisphenol-A and toxic azo dye solvent black-3 from single and binary solutions. These two chemicals are commonly used as an additive in the synthetic plastic industries. Among the tested twenty pristine and modified biochars, the pristine pinecone biochar produced at 750 °C revealed greater bisphenol-A removal. Simulation of the experimental data obtained for bisphenol-A and dye removal from the single-component solution offered a best-fit to Elovich (R² > 0.98) and pseudo-second-order (R² > 0.99) kinetic models, respectively. Whereas for the bisphenol-A + dye removal from binary solution, the values for bisphenol-A adsorption were best suited to Elovich (R² > 0.98), while pseudo-second-order (R² > 0.99) for dye removal. Similarly, the two-compartment model also demonstrated better values (R² > 0.92) for bisphenol-A and dye removal from single and binary solutions with greater F_fast values (except for bisphenol-A in binary solution). The Langmuir isotherm model demonstrated the highest regression coefficient values (R² > 0.99) for bisphenol-A and dye removal with the highest adsorption capacity of 38.387 mg g^-1 and 346.856 mg g^-1, correspondingly. Besides, the co-existence of humic acid revealed a positive impact on bisphenol-A removal, while the dye removal rate was slightly hindered in presence of humic acid. The absorption process showed monolayer coverage of biochar surface with contaminants using a chemisorption mechanism with fast reactions between functional groups on the adsorbate and adsorbent. Whereas the adsorption mechanism was primarily controlled by hydrogen bonding, hydrophobic and π-π electron-donor-acceptor interactions as confirmed by FTIR, XPS, and pH investigations.

Endocrine-disrupting chemicals and the risk of gestational diabetes mellitus: a systematic review and meta-analysis

OBJECTIVE

To conduct a comprehensive systematic review and meta-analysis to estimate the relationship between endocrine-disrupting chemicals (EDCs), including polychlorinated biphenyls (PCBs), poly-brominated diphenyl ethers (PBDEs), phthalates (PAEs), and per- and polyfluoroalkyl substances (PFAS) exposure and risk of gestational diabetes mellitus (GDM).

METHODS

Relevant studies from their inception to November 2021 were identified by searching EMBASE, PubMed, and Web of Science. The cohort and case-control studies that reported effect size with 95% confidence intervals (CIs) of EDC exposure and GDM were selected. The heterogeneity among the included studies was quantified by I² statistic. Publication bias was evaluated through the Begg and Egger tests.

RESULTS

Twenty-five articles with a total of 23,796 participants were found. Results indicated that exposure to PCBs has a significant influence on the incidence of GDM (OR = 1.14; 95% CI = 1.00--1.31; n = 8). The risk of GDM was found to be associated with PBDE exposure (OR = 1.32; 95% CI = 1.15-1.53; n = 4). PAEs and PFASs exposure were also positively associated with the risk of GDM, with summary ORs of 1.10 (95% CI = 1.03-1.16; n = 7 for PAEs) and 1.09 (95% CI = 1.02-1.16; n = 11 for PFASs), respectively. When only cohort studies were considered, the summary OR between PCBs exposure and the risk of GDM was 0.99 (95% CI = 0.91-1.09; n = 5). Meanwhile, the summary ORs from cohort studies for PBDEs, PAEs, and PFASs exposure were 1.12 (95% CI = 1.00-1.26; n = 2), 1.08 (95% CI = 1.02-1.15; n = 5), and 1.06 (95% CI = 1.00-1.12; n = 8), respectively. The Beggs and Egger tests did not show publication bias, and the sensitivity analyses did not change the results in this meta-analysis.

CONCLUSION

These results support that exposure to certain EDCs, including PCBs, PBDEs, PAEs, and PFAS, increase the risk of GDM. Further large-sample epidemiologic researches and mechanistic studies are needed to verify the potential relationship and biological mechanisms. These results are of public health significance because the daily EDC exposure is expected to increase the risk of GDM development.

Biomonitoring of bisphenol A, 4-nonylphenol, and 4-t-octylphenol in Turkish population: exposure and risk assessment

Biomonitoring studies are important tools to understand the effects of endocrine-disrupting compounds on human health. Up to now, there have been no biomonitoring and risk assessment studies conducted in Turkish population in which urinary bisphenol A (BPA), 4-nonylphenol (4-NP), and 4-t-octylphenol (4-t-OP) levels were measured simultaneously. The aim of this study is to measure urinary BPA, 4-NP, and 4-t-OP on Turkish population and conduct a risk assessment using urinary levels of chemicals of interest. During the study, liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used to measure urinary levels of above-mentioned chemicals, and human biomonitoring was used as a risk assessment tool in 103 volunteers, living in Mersin Region, Turkey. Urinary BPA, 4-NP, and 4-t-OP were founded as 0.0079 μg/g creatinine, 0.0177 μg/g creatinine, and 0.0114 μg/g creatinine, respectively. The obtained estimated daily intakes (EDIs) were calculated as 0.095 μg/kg bw/day, 0.041 μg/kg bw/day, and 0.091 μg/kg bw/day, for BPA, 4-NP, and 4-t-OP, respectively. In conclusion, although no potential health risk due to BPA and 4-NP exposure was observed, there might be health risks associated with 4-t-OP exposure in the Turkish population.

Regulatory and academic studies to derive reference values for human health: The case of bisphenol S

The close structural analogy of bisphenol (BP) S with BPA, a recognized endocrine-disrupting chemical and a substance of very high concern in the European Union, highlights the need to assess the extent of similarities between the two compounds and carefully scrutinize BPS potential toxicity for human health. This analysis aimed to investigate human health toxicity data regarding BPS, to find a point of departure for the derivation of human guidance values. A systematic and transparent methodology was applied to determine whether European or international reference values have been established for BPS. In the absence of such values, the scientific literature on human health effects was evaluated by focusing on human epidemiological and animal experimental studies. The results were analyzed by target organ/system: male and female reproduction, mammary gland, neurobehavior, and metabolism/obesity. Academic experimental studies were analyzed and compared to regulatory data including subchronic studies and an extended one-generation and reproduction study. In contrast to the regulatory studies, which were performed at dose levels in the mg/kg bw/day range, the academic dataset on specific target organs or systems showed adverse effects for BPS at much lower doses (0.5-10 μg/kg bw/day). A large disparity between the lowest-observed-adverse-effect levels (LOAELs) derived from regulatory and academic studies was observed for BPS, as for BPA. Toxicokinetic data on BPS from animal and human studies were also analyzed and showed a 100-fold higher oral bioavailability compared to BPA in a pig model. The similarities and differences between the two bisphenols, in particular the higher bioavailability of BPS in its active (non-conjugated) form and its potential impact on human health, are discussed. Based on the available experimental data, and for a better human protection, we propose to derive human reference values for exposure to BPS from the N(L)OAELs determined in academic studies.

Bisphenol A and Male Infertility: Role of Oxidative Stress

Bisphenol A (BPA) is an endocrine-disrupting chemical that is capable of mimicking, antagonizing, and interfering with the normal biological functioning of the endocrine system. BPA is used in diverse industries, hence its vast sources of exposure. Although the half-life of BPA is relatively short (<24 hours), studies have reported its detection in the urine of different populations. It, therefore, became important to investigate its effect on general health, including male reproductive health. The adverse effects of BPA on male fertility have been evaluated and reported from both in vivo and in vitro studies. Up to date, reports from randomized controlled trials remain controversial, as some revealed decreased sperm quality, sperm concentration, and total sperm count, while others reported that no adverse effect was seen after exposure. Findings from animal model studies and in vitro experiments have shown that exposure to BPA led to a reduction in sperm quality and increased sperm DNA fragmentation, and some even revealed altered expression of the gene that encodes gonadotropin-releasing hormone. This shows that BPA not only may adversely affect male fertility by acting as an endocrine disruptor but also can potentially impact male fertility via its possible contribution to oxidative stress. Therefore, this book chapter aims to identify and elucidate the effect of BPA exposure on male fertility, and to as well illustrate the mechanisms through which this occurs, while emphasizing the role of oxidative stress as a potential pathway.

UV-filter pollution: current concerns and future prospects

UV-filters are widely used in cosmetics and personal care products to protect users' skin from redamage caused by ultraviolet (UV) radiation from the sun. Globally, an estimated 16,000 to 25,000 tonnes of products containing UV-filters were used in 2014 with modern consumption likely to be much higher. Beyond this use in cosmetics and personal care products, UV-filters are also widely used to provide UV-stability in industrial products such as paints and plastics. This review discusses the main routes by which UV-filters enter aquatic environments and summarises the conclusions of studies from the past 10 years that have investigated the effects of UV-filters on environmentally relevant species including corals, microalgae, fish, and marine mammals. Safety data regarding the potential impact of UV-filters on human health are also discussed. Finally, we explore the challenges surrounding UV-filter removal and research on more environmentally friendly alternatives to current UV-filters.

Transcriptomic analysis reveals ligninolytic enzymes of white-rot fungus Phanerochaete sordida YK-624 participating in bisphenol F biodegradation under ligninolytic conditions

Bisphenol F (BPF) is widely used in the plastic manufacturing industry as a replacement for bisphenol A (BPA) because BPF and BPA have similar structures and comparable properties. However, BPF is ubiquitously present in the environment and has higher toxicity to humans. This study is the first to report BPF degradation using the white-rot fungus Phanerochaete sordida YK-624 under ligninolytic conditions (pH=4.5, 30 °C). P. sordida YK-624 almost completely degraded BPF within 4 days. Moreover, functional genes involved in BPF degradation were detected by RNA-Seq. Metabolic processes and peroxidases were enriched by GO analysis, and the metabolic pathway was enriched according to the KEGG pathway analysis. These results suggested that P. sordida YK-624 could secrete higher levels of ligninolytic enzymes lignin peroxidase (LiP) and manganese peroxidase (MnP) for BPF degradation. The results indicated that LiPs and MnPs are important for BPF degradation and cytochrome P450s play a small role. Furthermore, reliability of the RNA-Seq results was validated by qRT-PCR.

Methacrylic functionalized hybrid carbon nanomaterial for the selective adsorption and detection of progesterone in wastewater

Progesterone, an endocrine-disrupting chemical, has been frequently detected in wastewater for decades, posing a serious threat to ecological and human health. However, it is still a challenge to achieve the effective detection of progesterone in complex matrices water samples. In this study, a novel adsorbent CNT@CS/P(MAA) was prepared by grafting methacrylic polymers on the surface of modified carbon nanomaterials. Compared with other reported materials, the hybrid carbon nanomaterial could selectively identify the progesterone in the complex industrial pharmaceutical wastewater, and its adsorption performance is almost independent of the pH and environmental temperature. In addition, this nanomaterial could be reused with a good recovery rate. The prepared nanomaterials were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, nitrogen adsorption and desorption experiments, and thermogravimetric analysis. The results confirmed that the methacrylic polymers and chitosan layer were successfully grafted on the surface of carbon nanotubes. Adsorption isotherms, adsorption kinetics, and selectivity tests showed that CNT@CS/P(MAA) had a high adsorption capacity (44.45 mg·g-1), a fast adsorption rate and a satisfied selectivity for progesterone. Then, CNT@CS/P(MAA) was used as solid phase extraction sorbent and combined with HPLC to enrich progesterone from the wastewater samples. Under the optimum conditions, a good linearity was obtained with the correlation coefficient was 0.9998, and the limit of detection was 0.003 ng·mL-1. Therefore, this method could be used for the selective and effective detection of progesterone in industrial wastewater with complex substrates and provided a new method for the detection of progesterone in other environmental waters.

The endocrine disruptor 17β-trenbolone alters the relationship between pre- and post-copulatory sexual traits in male mosquitofish (Gambusia holbrooki)

It is now well-established that reproduction in wildlife can be disrupted by anthropogenic environmental changes, such as chemical pollution. However, very little is known about how these pollutants might affect the interplay between pre- and post-copulatory mechanisms of sexual selection. Here, we investigated the impacts of 21-day exposure of male eastern mosquitofish (Gambusia holbrooki) to a field-realistic level (average measured concentration: 11 ng/L) of the endocrine-disrupting chemical 17β-trenbolone (17β-TB) on pre- and post-copulatory reproductive traits. We examined male reproductive behaviour by testing the time spent near a female behind a partition, as well as the number of copulation attempts made, and the time spent chasing a female in a free-swimming context. Sperm traits were also assayed for all males. We found that exposure of male fish to 17β-TB altered the relationship between key pre- and post-copulatory reproductive traits. Furthermore, 17β-TB-exposed males had, on average, a higher percentage of motile sperm, and performed fewer copulation attempts than unexposed males. However, there was no overall effect of 17β-TB exposure on either the time males spent associating with or chasing females. Taken together, our findings demonstrate the potential for chemical pollutants to affect both pre- and post-copulatory sexual traits, and the interplay between these mechanisms of sexual selection in contaminated wildlife.

In Silico Analysis to Identify Molecular Targets for Chemicals of Concern: The Case Study of Flocoumafen, an Anticoagulant Pesticide

Rodenticides are pesticides used worldwide, with little information available regarding health consequences in wildlife and humans. The aim of the present study was to use virtual screening to identify potential targets for flocoumafen, a superwarfarin rodenticide. Blind docking of more than 841 human proteins was carried out employing AutoDock Vina. The strength of the ligand interaction with the proteins was quantified based on the binding affinity score (kcal/mol). Results indicate that flocoumafen could be a promiscuous ligand for diversity of cellular protein targets. The best complexes were obtained for prostaglandin F synthase (-14.2 kcal/mol) and serum albumin (-14.0 kcal/mol) followed by glucocorticoid receptor 2, matrix metalloproteinase-9, nuclear receptor ROR-alpha, and activin receptor type-1, all with values equal or better than -13.5 kcal/mol. Docking method validation based on the root-mean-square deviation showed that flocoumafen had good capability to predict corresponding co-crystallized poses; and molecular dynamics simulations suggested the complex with greater binding affinity was thermodynamically stable. Protein-protein interaction networks built with main protein targets revealed that protein kinase B (AKT1), ribosomal protein S6 kinase B1 (RPS6KB1), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), retinoid X receptor alpha (RXRA), and protein phosphatase 2 catalytic subunit alpha (PPP2CA) were major hub proteins, whereas the gene ontology analysis reported that cellular response to endogenous stimulus, protein binding, and the TOR complex were the biological processes, molecular function, and cell component enrichments, respectively. These results should motivate more ecotoxicity testing for flocoumafen and other superwarfarins, as well as precautionary legislation to minimize exposure to these highly toxic chemicals. Environ Toxicol Chem 2021;40:2034-2043. © 2021 SETAC.

Inappropriately sweet: Environmental endocrine-disrupting chemicals and the diabetes pandemic

Afflicting hundreds of millions of individuals globally, diabetes mellitus is a chronic disorder of energy metabolism characterized by hyperglycemia and other metabolic derangements that result in significant individual morbidity and mortality as well as substantial healthcare costs. Importantly, the impact of diabetes in the United States is not uniform across the population; rather, communities of color and those with low income are disproportionately affected. While excessive caloric intake, physical inactivity, and genetic susceptibility are undoubted contributors to diabetes risk, these factors alone fail to fully explain the rapid global rise in diabetes rates. Recently, environmental contaminants acting as endocrine-disrupting chemicals (EDCs) have been implicated in the pathogenesis of diabetes. Indeed, burgeoning data from cell-based, animal, population, and even clinical studies now indicate that a variety of structurally distinct EDCs of both natural and synthetic origin have the capacity to alter insulin secretion and action as well as global glucose homeostasis. This chapter reviews the evidence linking EDCs to diabetes risk across this spectrum of evidence. It is hoped that improving our understanding of the environmental drivers of diabetes development will illuminate novel individual-level and policy interventions to mitigate the impact of this devastating condition on vulnerable communities and the population at large.

Effect of bisphenol A on craniofacial cartilage development in zebrafish (Danio rerio) embryos: A morphological study

Bisphenol A (BPA), an endocrine-disrupting chemical, is present in everyday-used consumables and common household products. Although the side effects of BPA have been sufficiently explored, little is known the effects of environmentally relevant low levels of BPA on chondrogenesis in skeletal development. Here we used a morphological approach to investigate whether exposure to BPA (0, 0.0038, 0.05, 0.1, 1.0 μM) could affect craniofacial cartilage development of zebrafish embryo. Furthermore, we sought to determine receptor-mediated BPA induced chondrogenesis toxicity by co-exposing developing embryos to BPA and various inhibitors. Low-dose BPA affected heart rate and induced body and head elongation of larvae. Quantitative morphometric and histopathological analysis revealed that BPA exposure changed the angle and length of craniofacial cartilage elements and disrupted chondrocytes. BPA induced pharyngeal cartilage defects via multiple cellular pathways, including estrogen receptor, androgen receptor, and estrogen-related receptors. Our findings demonstrate that BPA alters the normal development of cartilage and craniofacial structures in zebrafish embryos. Furthermore, in this study we find multiple cellular pathways mediating the effects of BPA-induced craniofacial chondrogenesis toxicity. Further experiments will allow for establishing a connection between BPA and increased risk of congenital malformation of the facial cranium in BPA-exposed populations.

Prolonged atrazine exposure beginning in utero and adult uterine morphology in mice

Through drinking water, humans are commonly exposed to atrazine, a herbicide that acts as an endocrine and metabolic disruptor. It interferes with steroidogenesis, including promoting oestrogen production and altering cell metabolism. However, its precise impact on uterine development remains unknown. This study aimed to determine the effect of prolonged atrazine exposure on the uterus. Pregnant mice (n = 5/group) received 5 mg/kg body weight/day atrazine or DMSO in drinking water from gestational day 9.5 until weaning. Offspring continued to be exposed until 3 or 6 months of age (n = 5-9/group), when uteri were collected for morphological and molecular analyses and steroid quantification. Endometrial hyperplasia and leiomyoma were evident in the uteri of atrazine-exposed mice. Uterine oestrogen concentration, oestrogen receptor expression, and localisation were similar between groups, at both ages (P > 0.1). The expression and localisation of key epithelial-to-mesenchymal transition (EMT) genes and proteins, critical for tumourigenesis, remained unchanged between treatments, at both ages (P > 0.1). Hence, oestrogen-mediated changes to established EMT markers do not appear to underlie abnormal uterine morphology evident in atrazine exposure mice. This is the first report of abnormal uterine morphology following prolonged atrazine exposure starting in utero, it is likely that the abnormalities identified would negatively affect female fertility, although mechanisms remain unknown and require further study.

The endocrine disrupting effects of sodium arsenite in the rat testis is not mediated through macrophage activation

Arsenic (As) is an endocrine disrupting chemical that can disturb the male reproductive system. In a previous study, it was suggested that testicular macrophages could display a role in endocrine disruption induced by As exposure. This work aimed to evaluate the effects of chronic As exposure in the testis function of Wistar rats and examine the participation of macrophage activation and inflammatory response in these processes. We examined gene expression of steroidogenic machinery and immunological markers by RT-QPCR, plasma testosterone concentrations, sperm count and morphology, and histomorphometrical parameters after 60-days exposure to 1 or 5 mg.kg^-1.day^-1 of sodium arsenite, combined or not with 50 μg.kg^-1 of LPS administered one day before euthanasia. We have demonstrated that As exposure reduced the weight of androgen-dependent organs and induced changes in spermatogenesis, in particular at the highest dose. LPS and As co-exposure promoted a decrease in testosterone synthesis, but did not increase the overexpression of markers of macrophage activation seen in LPS-only rats. Our results suggest that As does not alter the testicular macrophage function, but under immunological challenges LPS and As can display a complex interaction, which could lead to endocrine disruption.

Disruption of fertility, placenta, pregnancy outcome, and multigenerational inheritance of hepatic steatosis by organotin exposure from contaminated seafood in rats

Early life exposure to endocrine-disrupting chemicals (EDCs) is an emerging risk factor for development of complications later in life and in subsequent generations. We previously demonstrated that exposure to the EDC organotin (OT), which is present in contaminated seafood, resulted in reproductive abnormalities in female rats. However, few studies have explored the effect of OT accumulation in seafood on pregnancy outcomes. This led us to consider the potential effects of the OT present in seafood on fertility, pregnancy, the placenta, and the offspring. In this investigation, we assessed whether exposure to the OT in contaminated seafood resulted in abnormal fertility and pregnancy features and offspring complications. OT in contaminated seafood (LNI) was administered to female rats, and their fertility, pregnancy outcomes, and fetal liver morphology were assessed. LNI caused abnormal fertility, a reduction in the total number of pups, and an increase in serum testosterone levels compared to controls. Furthermore, LNI exposure caused irregular uterine morphology with inflammation and fibrosis and led to a reduction in embryonic implantation. In pregnant rats, LNI caused abnormal lipid profiles and livers with steatosis features. LNI exposure also causes placental morpho-physiology disruption, a high presence of glycogen and inflammatory cells, and irregular lipid profiles. In addition, LNI exposure caused an increase in large amounts of carbohydrate and lipid delivery to the fetus via an increase in placental nutrient sensor protein expressions (GLUT1, IRβ/mTOR and Akt). In both genders of offspring, LNI exposure led to an increase in body weights, liver megakaryocytes, lipid accumulation, and oxidative stress (OS) levels. Collectively, these data suggest that OT exposure from contaminated seafood in female rats leads to reduced fertility, uterine implantation failure, pregnancy and placental metabolic outcome irregularities, offspring adiposity, liver steatosis, and an increase in OS. Furthermore, some of the effects of OT may be the result of obesogenic and multigenerational effects of OT in adult female rats.

Prepubertal acrylamide exposure causes dose-response decreases in spermatic production and functionality with modulation of genes involved in the spermatogenesis in rats

The increase in human infertility prevalence due to male reproductive disorders has been associated with extensive endocrine-disrupting chemical (EDC) exposure. Acrylamide (AA) is a compound formed spontaneously during heat processing of some foods that are mainly consumed by children and adolescents. In this study, we evaluated the prepubertal AA exposure effects on male adult reproductive physiology using a prepubertal experimental model to analyze the pubertal development, spermatogenesis hormones levels and genes expression involved in male reproductive function. This study is the first one to use the validated protocol to correlate the AA exposure with puberty development, as well as the AA-induced endocrine disrupting effects on reproductive axis. AA did not affect the age at puberty, the reproductive organ's weight and serum hormonal levels. AA reduces spermatogenesis, induces morphological and functional defects on sperm and alters transcript expression of sexual hormone receptors (Ar and Esr2), the transcript expression of Tnf, Egr2, Rhcg and Lrrc34. These findings suggest that excessive AA consumption may impair their reproductive capacity at adulthood, despite no changes in hormonal profile being observed.

Docking-based inverse virtual screening strategy for identification of novel protein targets for triclosan

Triclosan (TCS) is chemically designated as 5-chloro-2-(2,4-dichlorophenoxy) phenol and is considered as endocrine-disrupting chemical (EDC). The various diseases found due to exposure of TCS, have been linked with modulation of the human enoyl-acyl carrier protein-reductase (hER). However, the new protein targets for TCS other than hER, which are responsible for various diseases, are still unknown. In the present study, a bioinformatics approach was used to identify new possible targets for TCS. A text mining study was initially performed to understand the association of TCS in various biochemical processes. Discovery studio software 4.1 was used to carry out inverse virtual screening for 226 numbers of pathway proteins by docking study using CHARMm based docking tool, and twenty proteins were screened. CDOCKER energy values lower than -12.65 kcal/mol was considered for the screening of selected proteins. Three new proteins; Receptor-interacting protein 1 (RIP1), Apoptosis signal-regulating kinase 1 (ASK1) and B-cell lymphoma 2 (Bcl-2) from Apoptosis Signaling Pathway revealed best CDOCKER energy with triclosan which was -26.88, -23.34 and -22.96 kcal/mol respectively. The interaction of TCS with RIP1 and ASK1 were mostly hydrophobic; however, hydrogen bond type interaction was found in TCS/Bcl2 complex. Therefore, docking-based inverse virtual screening study suggests that TCS has other targets rather than hER, which can modulate various biochemical processes. The docking protocol was validated through evaluation of root-mean-square deviation (RMSD), key interaction score system (KISS) and the relationship between the docking energy and toxicity data available in ToxCast database. Low RMSD value (0.55 ˚A) and high KISS score (0.66) along with higher correlation (R² = 0.9798) between docking affinity and toxicity indicated that docking protocol can be used to optimize the binding energetics.

Environmental neglect: endocrine disruptors as underappreciated but potentially modifiable diabetes risk factors

Type 2 diabetes prevalence is increasing dramatically across the globe, imposing a tremendous toll on individuals and healthcare systems. Reversing these trends requires comprehensive approaches to address both classical and emerging diabetes risk factors. Recently, environmental toxicants acting as endocrine-disrupting chemicals (EDCs) have emerged as novel metabolic disease risk factors. EDCs implicated in diabetes pathogenesis include various inorganic and organic molecules of both natural and synthetic origin, including arsenic, bisphenol A, phthalates, polychlorinated biphenyls and organochlorine pesticides. Indeed, evidence implicates EDC exposures across the lifespan in metabolic dysfunction; moreover, specific developmental windows exhibit enhanced sensitivity to EDC-induced metabolic disruption, with potential impacts across generations. Importantly, differential exposures to diabetogenic EDCs likely also contribute to racial/ethnic and economic disparities. Despite these emerging links, clinical practice guidelines fail to address this underappreciated diabetes risk factor. Comprehensive approaches to stem the tide of diabetes must include efforts to address its environmental drivers.

Relationship between triclosan exposure and thyroid hormones: the Second Korean National Environmental Health Survey (2012-2014)

Background

5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan) is used as an antiseptic and is a potential endocrine-disrupting chemical that can affect thyroid hormone levels. This study evaluated the relationship between triclosan exposure and thyroid hormones.

Methods

Data from the second Korean National Environmental Health Survey (2012-2014) were analyzed. Triclosan exposure was evaluated using urinary triclosan concentrations and classified into 2 groups: 'below detection (< limit of detection [LOD])' vs. 'detected (≥ LOD).' Multiple linear regression analysis was conducted to determine the relationship between triclosan exposure and the serum thyroid hormone concentrations, adjusting for age, body mass index, urinary creatinine, and smoking status.

Results

When grouped by sex, triclosan exposure was positively associated with the serum thyroid-stimulating hormone (TSH) concentrations in females with marginal significance (β = 0.066, p = 0.058). However, no significant association was identified between triclosan exposure and serum total triiodothyronine and thyroxine in both males and females, and TSH in males.

Conclusions

This study is the first human study to evaluate the relationship between triclosan exposure and serum thyroid hormone concentrations in the Korean population. There was suggestive positive association between triclosan exposure and the serum TSH in females. Further studies need to evaluate the relationship between long-term exposure to low-dose triclosan and thyroid hormones.

Exposure to bisphenol A and diabetes risk in Mexican women

Bisphenol A (BPA) is an endocrine-disrupting chemical widely used in the production of polycarbonate plastics and epoxy resins, which has been previously linked to diabetes among non-Hispanic populations. As part of a case control study for breast cancer, only controls with BPA information were included in this report. The final sample size comprises 70 self-reported diabetics and 334 non-diabetics. Urinary free bisphenol A (BPA-F) (μg/L) was determined by solid-phase extraction and HPLC/FLD analysis. Logistic regression models were used to evaluate the association between BPA-F and self-reported diabetes. After adjusting by age, urinary BPA-F (4.06-224.53 μg/g creatinine) was associated with diabetes exposure (OR = 1.85; 95% CI 1.04, 3.28) compared with women in the reference category (0.67-4.05 μg/g creatinine). BPA may be an environmental cofactor of diabetes. More studies are needed to confirm this result, especially in Hispanic populations.

The endocrine disruptor, 17α-ethinyl estradiol, alters male mate choice in a freshwater fish

Among the handful of studies on the behavioural effects of endocrine disrupting chemicals (EDCs), only a few have set out to disentangle the mechanisms underpinning behavioural changes. In fish, previous studies have shown that both visual and chemical cues play an important role in mate choice. As such, contaminant-induced changes in either transmission or perception of mate choice cues could have direct implications for individual's fitness. One widespread contaminant of environmental concern is 17α-ethinyl estradiol (EE2), a synthetic estrogen used in the contraceptive pill. Here, we investigated the impacts of EE2 exposure (28 days; measured concentration 14 ng/L) on visual and chemical communication in wild guppies (Poecilia reticulata). Using a standard dichotomous mate choice assay, we first gave individual males (either control or EE2-exposed) the opportunity to court two size-matched females (one control and one EE2-exposed) using only visual cues. We then introduced chemical cues of females (control and EE2-exposed) to the trial tank. We found that there was no significant effect of EE2-treatment on total time males spent associating with the females, when given only visual cues. There was, however, a significant effect on male courtship behaviour, with both control and EE2-exposed males spending more time performing 'sigmoid' displays towards the visual cues of control females compared to EE2-exposed females. When males were presented with both visual and chemical female cues simultaneously, we found that males spent more time courting control females that were paired with EE2-chemical cues. Not only does our study uncover a previously unknown behavioural impact of EE2-exposure on chemical cues, but demonstrates that EE2-exposure can exert complex effects on visual and chemical communication in a mate choice context. Finally, we contribute to the discussion of intraspecific variability by providing data on the potential trade-offs underpinning contaminant-induced behavioural changes.

Vertical profiles and distributions of aqueous endocrine-disrupting chemicals in different matrices from the Pearl River Delta and the influence of environmental factors

The occurrence and distributions of selected endocrine-disrupting chemicals (EDCs), along with related environmental factors, were investigated in two rivers and six reservoirs in the Pearl River Delta. The vertical profiles of aqueous 4-tert-octylphenol (OP), 4-nonylphenol (NP), and estrone (E1) were constant, with little change in concentration between the surface and the river bottom, while higher aqueous concentrations of bisphenol A (BPA) were found in the bottom layers of the rivers. OP and NP in suspended particulate matter (SPM) were transferred from the surface to the bed layer, ultimately accumulating in the sediment. However, the particulate profiles of BPA and E1 both featured increases from the surface to the bottom layers and attenuation in the river bed. Dissolved oxygen (DO), water temperature, and pH were negatively correlated with the EDC concentrations, and negative relationships between DO and distribution coefficient (K_d) values for OP and NP were found as well. This indicated that these environmental parameters were primarily responsible for the EDC vertical distribution and SPM-water partitioning in the rivers. Positive relationships were observed between chlorophyll a and EDCs in the particulate phase, and the algae/water K_d values for EDCs in reservoirs were comparable to the SPM/water and sediment/water K_d values from the rivers. These results suggest that algae played an important role in regulating the distribution of EDCs in surface waters. Moreover, relationships between UV absorbance and EDCs revealed that π-π interactions were among the dissolved organic carbon (DOC)-EDC binding mechanisms and that DOC fractions with higher degrees of aromaticity and humification possessed higher affinities towards EDCs.

Maternal bisphenol A exposure disrupts spermatogenesis in adult rat offspring

Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC) that is widely used in the manufacturing of plastics and inner linings of food cans. Previously, it was reported that BPA disturbed the sexual dimorphic nucleus of the hypothalamus and delaying the onset of puberty attributed to an estrogenic action. In addition, BPA during the perinatal period increased LH serum concentrations in male offspring of dams at doses below the reproductive NOAEL (No Observable Adverse Effect Level) based upon World Health Organization guidelines. Based upon these findings, the objective of this study was to (1) determine the effects of perinatal treatment with low doses of BPA on regulation of spermatogenesis in adult offspring and (2) elucidate molecular mechanisms involved in the pathogenesis of gonadal dysfunction. The expression of genes related to spermatogenesis was disrupted with adverse consequences on sperm production, reserves, and function. Both BPA treated groups exhibited reduction in sperm production and epithelial height of seminiferous tubules, accompanied by diminished integrity of the acrosome and plasma membrane, decreased mitochondrial activity and increased incidence of morphological abnormalities. The sperm transit time was also slower. However, only in the group receiving the higher BPA dose was transcript expression of genes affected (reduced Ar and increased Esr1). It is of interest that serum testosterone levels were elevated in the same group where Ar was decreased. Data suggest that exposure to low BPA doses during hypothalamic sexual differentiation period produces permanent deleterious effects on spermatogenesis in adulthood.

Soil ecotoxicity study of DEHP with respect to multiple soil species

Di (2-ethylhexyl) phthalate or DEHP is classified as an endocrine-disrupting chemical. It is used as a plasticizer and pesticide additive. Moreover, it has a half-life of about 150-300 days. Thus, it is present in the soil environment and soil risk assessments for DEHP are needed. However, a number of studies have focused on the effects of DEHP in a single soil species. In this study, we conducted acute and chronic toxicity testing for DEHP using varied soil species, including plants, earthworms, soil algae, Collembola, and soil nematodes. In the plant toxicity test, no effect was observed at very high concentration except at some endpoints, and no effect was observed in the earthworm toxicity test. However, there were adverse effects on soil algae, Collembola, and nematodes. Notably, in the Collembola assays, the survival of adults decreased significantly at very high concentrations, whereas reproduction was hindered at low concentrations. Similar inhibition of reproduction was noted in the soil nematode assay. This suggests that DEHP has a greater influence on fertility than survival in the adult test species. However, besides hindered reproduction, no effect was observed on soil species at environmentally relevant concentrations.

Effect of activated carbon on removal of four phenolic endocrine-disrupting compounds, bisphenol A, bisphenol F, bisphenol S, and 4-tert-butylphenol in constructed wetlands

We investigated the effects of activated carbon, used as constructed wetlands (CWs) medium, on its ability to remove four emerging endocrine-disrupting chemicals (EDCs): bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS) and 4-tert-butylphenol (4-tert-BP). Two types of CWs planted with common reed were constructed, one with pumice rock called normal CW and the other was amended with activated carbon (AC) called AC-CW. EDCs contaminated synthetic wastewater (5 mg/L of each) was treated by CWs for 8 weeks. AC-CW completely and sustainably removed all four EDCs (98-100%) starting immediately and continuing throughout the experiment. Removal performances of all EDCs by AC-CW were significantly higher than those by normal CW. After experiment, no BPA and BPF and very small amounts of BPS and 4-tert-BP were detected in AC. In AC-CW, final elimination step of EDCs might be biodegradation. In addition, bacterial populations on AC component of AC-CW were one-two orders higher than those on the pumice rock of normal CW. Therefore, in AC-CW, EDCs were initially adsorbed onto AC, where they could be effectively degraded by high bacterial population.

Effect of endocrine disruptors on the ratio of X and Y chromosome-bearing live spermatozoa

Although equal numbers of X and Y spermatozoa are produced during spermatogenesis, the sex chromosome ratio in ejaculated spermatozoa can be altered by exposure to endocrine-disrupting chemicals (EDCs), which can be reflected by altered sex ratios at birth. Here, we hypothesized EDCs affect sperm functions and viability of X and Y chromosome-bearing human spermatozoa. After exposure to genistein (Gen), bisphenol A (BPA), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), dibromochloropropane (DBCP), and diazinon (Diaz), we evaluated motility, viability, capacitation, and differential viability of X and Y spermatozoa. All EDCs tested altered sperm viability, motility, and capacitation. Interestingly, the Y/X ratio of live spermatozoa was significantly lower in sperm treated with TCDD, DBCP, and Diaz than control spermatozoa. Our results suggest that some of EDCs have larger effects on the viability of Y spermatozoa than X spermatozoa, implicating that a reduction in Y sperm viability may result in a female-biased sex ratio of offspring at birth.

Hypothalamic-pituitary-ovarian axis perturbation in the basis of bisphenol A (BPA) reproductive toxicity in female zebrafish (Danio rerio)

Thousands of safety-related studies have been published on bisphenol A (BPA), an ubiquitous environmental pollutant with estrogenic activity and many other potential biological effects. In recent years, BPA exposure has been shown to cause anovulation and infertility through irreversible alteration of the hypothalamic-pituitary-gonadal axis in several organisms, including fish and mammals. Recently, the European Chemical Agency classified BPA as a "substance of very high concern" because of its endocrine-disrupting properties, which have serious effects on human health. Given the risk of exposure to BPA as a pollutant in the environment, food, and drinking water, the objective of our study was to assess the effects of this compound on the adeno-hypophysis by means of a histopathological and morphometric study of the gonadotroph cells. In addition, using quantitative real-time PCR (qRT-PCR) assays, we analyzed the changes in the expression of Cyp19b (an aromatase gene). Zebrafish were randomly distributed into five groups: a control group and 4 treated groups which were exposed to different BPA concentrations (1, 10, 100 and 1000 µg/L). The effects of the different doses on Cyp19b mRNA molecules followed a non-monotonic curve, with the 1 and 1000 µg/L doses causing dramatic decreases in the number of Cyp19b transcripts while the doses of 10 and 100 µg/L caused important increases. The consequences might be deregulation of gonadotropic hormones causing degeneration of gonadotropic cells, as observed in BPA treated animals. This is the first study in which the gonadotroph cells have been evaluated using histomorphological endpoints after BPA exposure in zebrafish.

An endocrine-disrupting agricultural contaminant impacts sequential female mate choice in fish

The environmental impact of endocrine-disrupting chemicals (EDCs)-compounds that interfere with endocrine system function at minute concentrations-is now well established. In recent years, concern has been mounting over a group of endocrine disruptors known as hormonal growth promotants (HGPs), which are natural and synthetic chemicals used to promote growth in livestock by targeting the endocrine system. One of the most potent compounds to enter the environment as a result of HGP use is 17β-trenbolone, which has repeatedly been detected in aquatic habitats. Although recent research has revealed that 17β-trenbolone can interfere with mechanisms of sexual selection, its potential to impact sequential female mate choice remains unknown, as is true for all EDCs. To address this, we exposed female guppies (Poecilia reticulata) to 17β-trenbolone at an environmentally relevant level (average measured concentration: 2 ng/L) for 21 days using a flow-through system. We then compared the response of unexposed and exposed females to sequentially presented stimulus (i.e., unexposed) males that varied in their relative body area of orange pigmentation, as female guppies have a known preference for orange colouration in males. We found that, regardless of male orange pigmentation, both unexposed and exposed females associated with males indiscriminately during their first male encounter. However, during the second male presentation, unexposed females significantly reduced the amount of time they spent associating with low-orange males if they had previously encountered a high-orange male. Conversely, 17β-trenbolone-exposed females associated with males indiscriminately (i.e., regardless of orange colouration) during both their first and second male encounter, and, overall, associated with males significantly less than did unexposed females during both presentations. This is the first study to demonstrate altered sequential female mate choice resulting from exposure to an endocrine disruptor, highlighting the need for a greater understanding of how EDCs may impact complex mechanisms of sexual selection.

Underutilized and Under Threat: Environmental Policy as a Tool to Address Diabetes Risk

PURPOSE OF REVIEW

Diabetes is a burgeoning threat to public health in the USA. Importantly, the burden of diabetes is not equally borne across society with marked disparities based on geography, race/ethnicity, and income. The etiology of global and population-specific diabetes risk remains incompletely understood; however, evidence linking environmental toxicants acting as endocrine-disrupting chemicals (EDCs), such as particulate matter and arsenic, with diabetes suggests that environmental policies could play an important role in diabetes risk reduction.

RECENT FINDINGS

Evidence suggests that disproportionate exposures to EDCs may contribute to subgroup-specific diabetes risk; however, no federal policies regulate EDCs linked to diabetes based upon diabetogenic potential. Nevertheless, analyses of European Union data indicate that such regulation could reduce diabetes-associated costs and disease burden. Federal laws only regulate EDCs indirectly. The accumulating evidence linking these chemicals with diabetes risk should encourage policymakers to adopt stricter environmental standards that consider both health and economic impacts.

Determination of the soil hazardous concentrations of bisphenol A using the species sensitivity approach

This study describes the determination of the species sensitivity distribution (SSD)-based soil hazardous contamination of bisphenol A for environmental risk assessment. We conducted a battery of bioassays, including acute assays using eight species from six different taxonomic groups and chronic assays using five species from four different taxonomic groups. We determined that our dataset satisfied Australia & New Zealand's guidelines for applying the SSD methodology. Finally, the chronic soil HC₅ and HC₅₀ values for bisphenol A were estimated to be 13.7 and 74.7mg/kg soil, respectively, for soil ecosystem protection against chronic exposure using the data generated from this and previous studies. Because the soil standard values of bisphenol A for protection of the soil ecosystem are not currently available, the HC values of bisphenol A that we suggested based on the SSD approach would be applied as fundamental data to establish soil standards of bisphenol A for soil ecosystem protection. To our knowledge, this is the first study reporting the soil hazardous concentration of bisphenol A for environmental risk assessment.

Applying adverse outcome pathways and species sensitivity-weighted distribution to predicted-no-effect concentration derivation and quantitative ecological risk assessment for bisphenol A and 4-nonylphenol in aquatic environments: A case study on Tianjin City, China

Adverse outcome pathways (AOPs) are a novel concept that effectively considers the toxic modes of action and guides the ecological risk assessment of chemicals. To better use toxicity data including biochemical or molecular responses and mechanistic data, we further developed a species sensitivity-weighted distribution (SSWD) method for bisphenol A and 4-nonylphenol. Their aquatic predicted-no-effect concentrations (PNECs) were derived using the log-normal statistical extrapolation method. We calculated aquatic PNECs of bisphenol A and 4-nonylphenol with values of 4.01 and 0.721 µg/L, respectively. The ecological risk of each chemical in different aquatic environments near Tianjin, China, a coastal municipality along the Bohai Sea, was characterized by hazard quotient and probabilistic risk quotient assessment techniques. Hazard quotients of 7.02 and 5.99 at 2 municipal sewage sites using all of the endpoints were observed for 4-nonylphenol, which indicated high ecological risks posed by 4-nonylphenol to aquatic organisms, especially endocrine-disrupting effects. Moreover, a high ecological risk of 4-nonylphenol was indicated based on the probabilistic risk quotient method. The present results show that combining the SSWD method and the AOP concept could better protect aquatic organisms from adverse effects such as endocrine disruption and could decrease uncertainty in ecological risk assessment. Environ Toxicol Chem 2018;37:551-562. © 2017 SETAC.