Long-term effects of environmental endocrine disruptors on reproductive physiology and behavior

Sex-specific effects on elements of the social brain neural network in Wistar rats from perinatal exposure to FireMaster 550 or its components

Developmental exposure to chemical flame retardants (FRs) has been linked to a variety of neurodevelopmental disorders and abnormal socioemotional behaviors in human and laboratory animal studies. We have previously shown in Wistar rats that gestational and lactational exposure to the FR mixture Firemaster 550 (FM 550) or its brominated or organophosphate ester (OPFR) components (at 2000 µg, 1000 µg, and 1000 µg oral to the dam respectively (absolute and not by bodyweight)) results in increased anxiety-like behaviors in females and decreased sociality in both sexes. Using their siblings, this study characterized sex and chemical specific targets of disruption in brain regions underlying each behavioral phenotype. Offspring were exposed across gestation and lactation then prepared for either immunohistochemistry or autoradiography at postnatal day 90 to quantify expression of serotonin, estrogen receptor α (ERα), and oxytocin receptor (OTR) in multiple brain regions. No effect of exposure was found in males for any biological target. In females, serotonin innervation was increased in the medial amygdala of FM 550 exposed animals while ERα expression in the bed nucleus of the stria terminalis (BNST) was reduced by FM 550 and OPFR. Evidence of disrupted OTR was observed in males, particularly the BNST but considered an exploratory finding given the small sample size. These results begin to shed light on the mechanisms by which developmental FR exposure alters socioemotional behaviors of relevance to neurodevelopmental disorders.

Environmental risk assessment in the EU regulation of medicines for human use: an analysis of stakeholder perspectives on its current and future role

An environmental risk assessment (ERA) is mandatory for all applications for marketing authorisation of medicines in the European Union (EU). We investigated stakeholder perspectives on the role of the ERA in EU regulation of medicines for human use. We discuss the current position of the ERA and the current conduct and assessment of the ERA, such as the required expertise, data, and studies, its applicability to generic drugs, and its use in regulatory decision-making. We also discuss future perspectives, including extension of the ERA to cover antimicrobial resistance, improved risk mitigation, impact on 'over-the-counter' (OTC) status, and incorporation into reimbursement considerations.

Main factors influencing the perceived health risk of endocrine-disrupting chemicals: A systematic literature review

Endocrine-disrupting chemicals (EDCs) are linked to rising health issues such as infertility, childhood obesity, and asthma. While some research exists on health risk perceptions of EDCs, a comprehensive understanding across different populations and contexts is needed. We performed a systematic literature review, examining 45 articles published between 1985 and 2023, focusing on both the risk perception of EDCs as a whole as well as individual EDCs found in the environment (e.g., pesticides, bisphenol A, and phthalates). We identified four major categories of factors influencing EDC risk perception: sociodemographic factors (with age, gender, race, and education as significant determinants), family-related factors (highlighting increased concerns in households with children), cognitive factors (indicating that increased EDC knowledge generally led to increased risk perception), and psychosocial factors (with trust in institutions, worldviews, and health-related concerns as primary determinants). This review highlights the complex nature of EDC risk perception, shaped by sociodemographic, family, cognitive, and psychosocial factors, essential for policymakers in crafting educational and communication strategies. Future research should expand to cover more EDCs, use representative samples, and explore the influence of psychosocial factors on risk perception more deeply.

Pollution characteristics and risk assessment of endocrine-disrupting chemicals in surface water of national (freshwater) aquatic germplasm resource reserves in Guangdong Province

The distribution, composition, and risk assessment of 8 EDCs in the surface water of 14 national aquatic germplasm resource reserves (freshwater) were investigated during dry and wet seasons. Bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) were the main contributors of the 8 EDCs. The concentrations of phenolic pollutants in surface water during the dry season were higher than those in the wet season. However, no significant seasonal differences were found among the steroid hormones. According to the evaluation of estrogenic activity (EEQ > 1.0), E2 and EE2 were the main contributors to estrogenic activity. EDC mixtures posed a higher risk to crustaceans and fish (RQ > 1.0) and a moderate to high risk to algae (RQ > 0.1). Fish were the most sensitive aquatic organisms. In the study areas, EE2, E1, BPA, NP, and E2 had a higher risk than the other three compounds and should be controlled as a priority.

Phthalate Acid Esters (PAEs) in Indoor Dust from Decoration Material Stores: Occurrence, Sources, and Health Risks

Phthalate acid esters (PAEs) are one of the most widely used plasticizers globally, extensively employed in various decoration materials. However, studies on the impact of these materials on indoor environmental PAE pollution and their effects on human health are limited. In this study, forty dust samples were collected from four types of stores specializing in decoration materials (flooring, furniture boards, wall coverings, and household articles). The levels, sources, exposure doses, and potential health risks of PAEs in dust from decoration material stores were assessed. The total concentrations of Σ9PAE (the sum of nine PAEs) in dust from all decoration-material stores ranged from 46,100 ng/g to 695,000 ng/g, with a median concentration of 146,000 ng/g. DMP, DEP, DBP, and DEHP were identified as the predominant components. Among all stores, furniture board stores exhibited the highest Σ9PAE (159,000 ng/g, median value), while flooring stores exhibited the lowest (95,300 ng/g). Principal component analysis (PCA) showed that decoration materials are important sources of PAEs in the indoor environment. The estimated daily intakes of PAEs through non-dietary dust ingestion and dermal-absorption pathways among staff in various decoration-material stores were 60.0 and 0.470 ng/kg-bw/day (flooring stores), 113 and 0.780 ng/kg-bw/day (furniture board stores), 102 and 0.510 ng/kg-bw/day (wall covering stores), and 114 and 0.710 ng/kg-bw/day (household article stores). Particularly, staff in wall-covering and furniture-board stores exhibited relatively higher exposure doses of DEHP. Risk assessment indicated that although certain PAEs posed potential health risks, the exposure levels for staff in decoration material stores were within acceptable limits. However, staff in wall covering stores exhibited relatively higher risks, necessitating targeted risk-management strategies. This study provides new insights into understanding the risk associated with PAEs in indoor environments.

Lifestyle and Chemicals: Exploring Behavioral Habits Related to Endocrine Disruptor Exposure Among the General Population of Saudi Arabia

BACKGROUND

Endocrine-disrupting chemicals (EDCs) interfere with hormonal systems, potentially causing metabolic, reproductive, and neurological issues, as well as hormone-related cancers. Found in everyday products, EDCs accumulate in body tissues over time, with adverse effects depending on the dose and duration of exposure. This study aims to explore behaviors related to EDC exposure among Saudi citizens to assess the need for further risk reduction interventions.

METHODOLOGY

This cross-sectional study employed a validated, self-administered online questionnaire to assess daily life behaviors associated with EDC exposure. A total of 563 participants were recruited using convenient sampling through online platforms.

RESULTS

The study revealed that a significant majority of participants were aged 18-25 years (48.67%, n=274). On average, participants scored 32.78 out of a maximum of 60 for potential EDC exposure, with scores ranging from 13 to 54 points. The majority (85.26%, n=480) fell into the moderate potential exposure category, while a small minority (4.26%, n=24) exhibited high potential risk based on their reported daily habits, predominantly among male participants (95.83%, n=23). A significant majority (72.65%, n=409) indicated a likelihood of adopting lifestyle changes to reduce exposure to harmful substances.

CONCLUSION

This study reveals diverse behavioral patterns linked to endocrine disruptor exposure among the general population in Saudi Arabia. Interestingly, the participants showed a positive attitude and willingness to change their risky behaviors. These findings underscore the necessity for educational programs and public health campaigns aimed at addressing gaps in knowledge. Encouraging the public to adopt behaviors that reduce exposure is essential to minimizing the potential long-term effects of EDCs.

Prenatal exposure to Di(2-ethylhexyl) phthalate and high-fat diet synergistically disrupts gonadal function in male mice†

Prenatal exposure to Di (2-ethylhexyl) phthalate (DEHP) impairs the reproductive system and causes fertility defects in male offspring. Additionally, high-fat (HF) diet is a risk factor for reproductive disorders in males. In this study, we tested the hypothesis that prenatal exposure to a physiologically relevant dose of DEHP in conjunction with HF diet synergistically impacts reproductive function and fertility in male offspring. Female mice were fed a control or HF diet 7 days prior to mating and until their litters were weaned on postnatal day 21. Pregnant dams were exposed to DEHP or vehicle from gestational day 10.5 until birth. The male offspring's gross phenotype, sperm quality, serum hormonal levels, testicular histopathology, and testicular gene expression pattern were analyzed. Male mice born to dams exposed to DEHP + HF had smaller testes, epididymides, and shorter anogenital distance compared with those exposed to HF or DEHP alone. DEHP + HF mice had lower sperm concentration and motility compared with DEHP mice. Moreover, DEHP + HF mice had more apoptotic germ cells, fewer Leydig cells, and lower serum testosterone levels than DEHP mice. Furthermore, testicular mRNA expression of Dnmt1 and Dnmt3a was two to eight-fold higher than in DEHP mice by qPCR, suggesting that maternal HF diet and prenatal DEHP exposure additively impact gonadal function by altering the degree of DNA methylation in the testis. These results suggest that the combined exposure to DEHP and high-fat synergistically impairs reproductive function in male offspring, greater than exposure to DEHP or HF diet alone.

Hues of risk: investigating genotoxicity and environmental impacts of azo textile dyes

The textile industry, with its extensive use of dyes and chemicals, stands out as a significant source of water pollution. Exposure to certain textile dyes, such as azo dyes and their breakdown products like aromatic amines, has been associated with health concerns like skin sensitization, allergic reactions, and even cancer in humans. Annually, the worldwide production of synthetic dyes approximates 7 × 107 tons, of which the textile industry accounts for over 10,000 tons. Inefficient dyeing procedures result in the discharge of 15-50% of azo dyes, which do not adequately bind to fibers, into wastewater. This review delves into the genotoxic impact of azo dyes, prevalent in the textile industry, on aquatic ecosystems and human health. Examining different families of textile dye which contain azo group in their structure such as Sudan I and Sudan III Sudan IV, Basic Red 51, Basic Violet 14, Disperse Yellow 7, Congo Red, Acid Red 26, and Acid Blue 113 reveals their carcinogenic potential, which may affect both industrial workers and aquatic life. Genotoxic and carcinogenic characteristics, chromosomal abnormalities, induced physiological and neurobehavioral changes, and disruptions to spermatogenesis are evident, underscoring the harmful effects of these dyes. The review calls for comprehensive investigations into the toxic profile of azo dyes, providing essential insights to safeguard the aquatic ecosystem and human well-being. The importance of effective effluent treatment systems is underscored to mitigate adverse impacts on agricultural lands, water resources, and the environment, particularly in regions heavily reliant on wastewater irrigation for food production.

Genistein effect in cultured ovine ovarian granulosa cells

Genistein, an isoflavone has the potential to mimic, augment, or dysregulate the steroid hormone production pathways. We hypothesized that genistein affects the granulosa cell (GCs) functions through a series of biochemical, molecular, and genomic cascades. The present study was conducted to evaluate the impact of genistein exposure on GCs viability, apoptosis, and steroidogenesis. The present study involved 3/5 days of exposure to genistein on GCs collected from abattoir-derived ovine ovaries at doses of 0, 1, 10, 25, 50, and 100 µM. The harvested GCs were used for growth, cytotoxicity, and gene expression studies related to apoptosis, growth, and steroidogenesis. We observed that genistein had both stimulatory at 10 and 25 µM levels as well as inhibitory effects at 50 and 100 µM levels on the growth and proliferation of GCs. Genistein significantly decreased the levels of 17β-estradiol at higher exposure (50 and 100 µM), whereas the progesterone level increased significantly as the genistein exposure increased. Additionally, genistein could also alter the mRNA expression of the steroidogenic receptor, enzymes, proteins, and growth-related genes suggesting that genistein could potentially alter the steroidogenic pathways. We conclude that genistein can interfere with cell survival and steroidogenesis by exhibiting a dose-dependent biphasic response on the viability, growth-related parameters, and the synthesis of 17β-estradiol in the cultured GCs.

Effects of a TAML catalyst on mice exposed during pregnancy and lactation

Tetra-amido macrocyclic ligands (TAMLs) are catalysts designed to mimic endogenous peroxidases that can degrade pollutants. Before TAMLs gain widespread use, it is first important to determine if they have endocrine disrupting properties. In this study, we evaluated the effects of the iron TAML, NT7, on hormone-sensitive outcomes in mice exposed during pregnancy and lactation, and on their litters prior to weaning. We administered NT7 at one of three doses to mice via drinking water prior to and then throughout pregnancy and lactation. Two hormonally active pharmaceuticals, ethinyl estradiol (EE2) and flutamide (FLUT), a known estrogen receptor agonist and androgen receptor antagonist, respectively, were also included. In the females, we measured pre- and post-parturition weight, length of pregnancy, organ weights at necropsy, and morphology of the mammary gland at the end of the lactational period. We also quantified maternal behaviors at three stages of lactation. For the offspring, we measured litter size, litter weights, and the achievement of other developmental milestones. We observed only one statistically significant effect of NT7, a decrease in the percentage of pups with ear opening at postnatal day 5. This contrasts with the numerous effects of EE2 on both the mother and the litter, as well as several modest effects of FLUT. The approach taken in this study could provide guidance for future studies that aim to evaluate novel compounds for endocrine disrupting properties.

Identification of hippocampal area CA2 in hamster and vole brain

Prairie voles (Microtus ochrogaster) and Syrian, or golden, hamsters (Mesocricetus auratus) are closely related to mice (Mus musculus) and are commonly used in studies of social behavior including social interaction, social memory, and aggression. Hippocampal area CA2 is known to play a key role in these behaviors in mice and responds to social stimuli in rats, but CA2 has yet to be characterized in hamsters or voles, which are also used in studies of social behaviors. Here, we used immunofluorescence to determine whether CA2 could be molecularly identified in tissue from voles and hamsters. We found that  staining for many CA2 markers was similar in these three species, with labeling seen in neurons at the distal end of the mossy fibers . In contrast, although perineuronal nets (PNNs) surround CA2 cells in mice, PNN staining differed across species. In voles, both CA2 and CA3 were labeled, whereas in hamsters, labeling was seen primarily in CA3. These results demonstrate that CA2 can be molecularly distinguished from neighboring CA1 and CA3 areas in voles and hamsters with several antibodies commonly used in mice. However, PNN staining is not useful for identifying CA2 in voles or hamsters, suggestive of differing roles for either PNNs or for the hippocampal subregions in social behavior. These findings reveal commonalities across species in the molecular profile of CA2 and should facilitate future studies of CA2 in these species.

Pollution and endometriosis: A deep dive into the environmental impacts on women's health

BACKGROUND

The interaction between pollution and endometriosis is a pressing issue that demands immediate attention. The impact of pollution, particularly air and water pollution, or occupational hazards, on hormonal disruption and the initiation of endometriosis remains a major issue.

OBJECTIVES

This narrative review aims to delve into the intricate connection between pollution and endometriosis, shedding light on how environmental factors contribute to the onset and severity of this disease and, thus, the possible public health policy implications.

DISCUSSION

Endocrine-disrupting chemicals (EDCs) in pollutants dysregulate the hormonal balance, contributing to the progression of this major gynaecological disorder. Air pollution, specifically PM2.5 and PAHs, has been associated with an increased risk of endometriosis by enhancing chronic inflammation, oxidative stress, and hormonal imbalances. Chemical contaminants in water and work exposures, including heavy metals, dioxins, and PCBs, disrupt the hormonal regulation and potentially contribute to endometriosis. Mitigating the environmental impact of pollution is required to safeguard women's reproductive health. This requires a comprehensive approach involving stringent environmental regulations, sustainable practices, responsible waste management, research and innovation, public awareness, and collaboration among stakeholders.

CONCLUSION

Public health policies have a major role in addressing the interaction between pollution and endometriosis in a long-term commitment.

Identification of hippocampal area CA2 in hamster and vole brain

Prairie voles (Microtus ochrogaster) and Syrian, or golden, hamsters (Mesocricetus auratus) are closely related to mice (Mus musculus) and rats (Rattus norvegicus, for example) and are commonly used in studies of social behavior including social interaction, social memory, and aggression. The CA2 region of the hippocampus is known to play a key role in social memory and aggression in mice and responds to social stimuli in rats, likely owing to its high expression of oxytocin and vasopressin 1b receptors. However, CA2 has yet to be identified and characterized in hamsters or voles. In this study, we sought to determine whether CA2 could be identified molecularly in vole and hamster. To do this, we used immunofluorescence with primary antibodies raised against known molecular markers of CA2 in mice and rats to stain hippocampal sections from voles and hamsters in parallel with those from mice. Here, we report that, like in mouse and rat, staining for many CA2 proteins in vole and hamster hippocampus reveals a population of neurons that express regulator of G protein signaling 14 (RGS14), Purkinje cell protein 4 (PCP4) and striatal-enriched protein tyrosine phosphatase (STEP), which together delineate the borders with CA3 and CA1. These cells were located at the distal end of the mossy fiber projections, marked by the presence of Zinc Transporter 3 (ZnT-3) and calbindin in all three species. In addition to staining the mossy fibers, calbindin also labeled a layer of CA1 pyramidal cells in mouse and hamster but not in vole. However, Wolframin ER transmembrane glycoprotein (WFS1) immunofluorescence, which marks all CA1 neurons, was present in all three species and abutted the distal end of CA2, marked by RGS14 immunofluorescence. Staining for two stress hormone receptors-the glucocorticoid (GR) and mineralocorticoid (MR) receptors-was also similar in all three species, with GR staining found primarily in CA1 and MR staining enriched in CA2. Interestingly, although perineuronal nets (PNNs) are known to surround CA2 cells in mouse and rat, we found that staining for PNNs differed across species in that both CA2 and CA3 showed staining in voles and primarily CA3 in hamsters with only some neurons in proximal CA2 showing staining. These results demonstrate that, like in mouse, CA2 in voles and hamsters can be molecularly distinguished from neighboring CA1 and CA3 areas, but PNN staining is less useful for identifying CA2 in the latter two species. These findings reveal commonalities across species in molecular profile of CA2, which will facilitate future studies of CA2 in these species. Yet to be determined is how differences in PNNs might relate to differences in social behavior across species.

2,4-Dichlorophenol Shows Estrogenic Endocrine Disruptor Activity by Altering Male Rat Sexual Behavior

Chlorophenols (CPs) have been extensively used worldwide as a treatment to prevent the growth and proliferation of different microorganisms, mainly in the wood and farm industries. Chlorine has been used for water disinfection, and phenol groups are water contaminants; these two groups can react with each other to form species such as 2,4-dichlorophenol (2,4-DCP). 2,4-DCP is still used as an herbicide in many countries such as Mexico. CPs have been largely analyzed, like bisphenol A, for their probable endocrine-disrupting effects in humans and aquatic animals. We still do not understand whether these endocrine responses can be manifested as an impairment in sexual behavior in rodents. With the present toxicology study, the endocrine-disrupting effects of 2,4-DCP on male sexual behavior were investigated. Sexually naïve male Wistar rats were used to assess the endocrine-disrupting effects of 2,4-DCP. The rats were divided into two groups: one control group and one experimental group that was administered 1.25 mg/day of 2,4-DCP for 45 days. After completing treatment, the male sexual behavior of the rats was evaluated. The results of this investigation demonstrated that 2,4-DCP affected male sexual behavior. A decrease in mount latency, intromission latency, and post ejaculation period compared with the control animals was found.

Environmental endocrine disruptors and pregnane X receptor action: A review

The pregnane X receptor (PXR) is a kind of orphan nuclear receptor activated by a series of ligands. Environmental endocrine disruptors (EEDs) are a wide class of molecules present in the environment that are suspected to have adverse effects on the endocrine system by interfering with the synthesis, transport, degradation, or action of endogenous hormones. Since EEDs may modulate human/rodent PXR, this review aims to summarize EEDs as PXR modulators, including agonists and antagonists. The modular structure of PXR is also described, interestingly, the pharmacology of PXR have been confirmed to vary among different species. Furthermore, PXR play a key role in the regulation of endocrine function. Endocrine disruption of EEDs via PXR and its related pathways are systematically summarized. In brief, this review may provide a way to understand the roles of EEDs in interaction with the nuclear receptors (such as PXR) and the related pathways.

Insight into the Potential Mechanisms of Endocrine Disruption by Dietary Phytoestrogens in the Context of the Etiopathogenesis of Endometriosis

Phytoestrogens (PEs) are estrogen-like nonsteroidal compounds derived from plants (e.g., nuts, seeds, fruits, and vegetables) and fungi that are structurally similar to 17β-estradiol. PEs bind to all types of estrogen receptors, including ERα and ERβ receptors, nuclear receptors, and a membrane-bound estrogen receptor known as the G protein-coupled estrogen receptor (GPER). As endocrine-disrupting chemicals (EDCs) with pro- or antiestrogenic properties, PEs can potentially disrupt the hormonal regulation of homeostasis, resulting in developmental and reproductive abnormalities. However, a lack of PEs in the diet does not result in the development of deficiency symptoms. To properly assess the benefits and risks associated with the use of a PE-rich diet, it is necessary to distinguish between endocrine disruption (endocrine-mediated adverse effects) and nonspecific effects on the endocrine system. Endometriosis is an estrogen-dependent disease of unknown etiopathogenesis, in which tissue similar to the lining of the uterus (the endometrium) grows outside of the uterus with subsequent complications being manifested as a result of local inflammatory reactions. Endometriosis affects 10-15% of women of reproductive age and is associated with chronic pelvic pain, dysmenorrhea, dyspareunia, and infertility. In this review, the endocrine-disruptive actions of PEs are reviewed in the context of endometriosis to determine whether a PE-rich diet has a positive or negative effect on the risk and course of endometriosis.

A robust multi-residue method for the monitoring of 25 endocrine disruptors at ultra-trace levels in surface waters by SPE-LC-MS/MS

Estrogenic endocrine disruptors are one of the biggest ecotoxicological threats in water that pose a significant ecological burden and health-risk for humans due to their high biological activity and proven additive effects. Therefore, we have developed and validated the most comprehensive and ultra-sensitive analytical method published to date, for reliable quantification of 25 high-risk endocrine disruptors at their ecologically relevant concentrations: naturally excreted hormones (estradiol, estrone, estriol, testosterone, corticosterone, and progesterone), synthetic hormones used for contraception and menopausal symptoms (ethinylestradiol, drospirenone, chlormadinone acetate, norgestrel, gestodene, tibolone, norethindrone, dienogest, and cyproterone) and bisphenols (BPS, BPA, BPF, BPE, BPAF, BPB, BPC, and BPZ). It is based on a solid-phase extraction of water samples, followed by a robust dansyl chloride derivatization with detection by liquid chromatography-tandem mass spectrometry with a single sample preparation and two analytical methods using the same analytical column and mobile phases. The achieved limits of quantitation are in the sub-ng L^-1 range, and detection limits as low as 0.02 ng L^-1, meeting the newest proposal for environmental quality standards (EQS) by the EU water framework directive for estradiol and ethinylestradiol. The method was extensively validated and applied to seven representative Slovenian water samples, where we detected 21 out of 25 analytes; 13 were quantified in at least one sample. Estrone and progesterone were quantified in all samples, reaching levels up to 50 ng L^-1; ethinylestradiol was higher than the current EQS (0.035 ng L^-1) in three samples, and estradiol was above its EQS (0.4 ng L^-1) in one sample, proving the method's applicability and the necessity for monitoring these pollutants.

Awareness Regarding Sex Hormone Disruptors in Everyday Products Among Females of Reproductive Age in Al-Jouf, the Kingdom of Saudi Arabia

Background and objective Endocrine-disrupting chemicals (EDCs) are natural or synthetic molecules that can alter and affect the operations of the hormonal system of an organism. These compounds include plastic consumer products and food containers such as phytoestrogen, which is also naturally present in food. EDCs can be found in the cord blood and maternal blood of pregnant women, as well as colostrum. Hence, they may affect not only the mother but also the offspring. In this study, we aimed to evaluate the awareness among females of reproductive age regarding the nature, source, as well as physiological and psychological burden associated with sex hormones disruptors. Methods A descriptive cross-sectional study was conducted among females between the age of 15-45 years in the Al-Jouf region, Saudi Arabia. A self-administrated questionnaire was used as the data collection tool; it consisted of multiple-choice questions to obtain information on the awareness among the females. In this study, females were classified into those with good knowledge and those with poor knowledge based on their level of knowledge by using a scoring system with a total score of 12. IBM SPSS Statistics version 24 (IBM Corp., Armonk, NY) was used to analyze the collected data. Results The study included 491 females; 6.6% of them had been using soya-containing products for a long time, and 32.5% reported using oatmeal for a long time. The majority (86.2%) did not use any other hormonal therapy. There were significant differences in the knowledge about sex hormone disruptors among the participants, and women with poorer knowledge about sex hormone disruptors were significantly less likely to report the long-time usage of soya-containing food when compared to women with greater knowledge (2.2% vs. 4.2%, p<0.001). The results showed that women with poorer knowledge were also significantly less likely to report the usage of hormonal therapies when compared to women with greater knowledge (6.7% vs. 7.2%, p<0.001), indicating that the usage of these chemicals is higher in women with greater knowledge although they are aware of their effects. Conclusion The study showed that females had good knowledge about the nature and usage of EDCs but poor knowledge about their impact. The knowledge of females was associated with their behavior regarding the usage of such products.

Personal air pollutant exposure monitoring in South African children in the VHEMBE birth cohort

The burden of disease associated with environmental exposures disproportionately impacts residents of low- and middle-income countries. Children living in rural regions of these countries may experience higher exposure to insecticides from indoor residual spraying used for malaria control and household air pollution. This study evaluated environmental exposures of children living in a rural region of South Africa. Quantifying exposure levels and identifying characteristics that are associated with exposure in this geographic region has been challenging due to limitations with available monitoring techniques. Wearable passive samplers have recently been shown to be a convenient and reliable tool for assessing personal exposures. In this study, a passive sampler wristband, known as Fresh Air wristband, was worn by 49 children (five-years of age) residing in the Limpopo province of South Africa. The study leveraged ongoing research within the Venda Health Examination of Mothers, Babies, and their Environment (VHEMBE) birth cohort. A wide range of chemicals (35 in total) were detected using the wristbands, including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, phthalates, and organophosphate esters (OPEs) flame retardants. Higher concentrations of PAHs were observed among children from households that fell below the food poverty threshold, did not have access to electric cookstoves/burners, or reported longer times of cooking or burning materials during the sampling period. Concentrations of p,p'-DDD and p,p'-DDT were also found to be elevated for children from households falling below the food poverty threshold as well as for children whose households were sprayed for malaria control within the previous 1.5 years. This study demonstrates the feasibility of using passive sampler wristbands as a non-invasive method for personal exposure assessment of children in rural regions of South Africa to complex mixtures environmental contaminants derived from a combination of sources. Future studies are needed to further identify and understand the effects of airborne environmental contaminants on childhood development and strategies to mitigate exposures.

Xeno-Estrogenic Pesticides and the Risk of Related Human Cancers

In recent decades, "environmental xenobiotic-mediated endocrine disruption", especially by xeno-estrogens, has gained a lot of interest from toxicologists and environmental researchers. These estrogen-mimicking chemicals are known to cause various human disorders. Pesticides are the most heavily used harmful xenobiotic chemicals around the world. The estrogen-mimicking potential of the most widely used organochlorine pesticides is well established. However, their effect is not as clearly understood among the plethora of effects these persistent xenobiotics are known to pose on our physiological system. Estrogens are one of the principal risk modifiers of various disorders, including cancer, not only in women but in men as well. Despite the ban on these xenobiotics in some parts of the world, humans are still at apparent risk of exposure to these harmful chemicals as they are still widely persistent and likely to stay in our environment for a long time owing to their high chemical stability. The present work intends to understand how these harmful chemicals may affect the risk of the development of estrogen-mediated human cancer.

UV-Cured Green Polymers for Biosensorics: Correlation of Operational Parameters of Highly Sensitive Biosensors with Nano-Volumes and Adsorption Properties

The investigated polymeric matrixes consisted of epoxidized linseed oil (ELO), acrylated epoxidized soybean oil (AESO), trimethylolpropane triglycidyl ether (RD1), vanillin dimethacrylate (VDM), triarylsulfonium hexafluorophosphate salts (PI), and 2,2-dimethoxy-2-phenylacetophenone (DMPA). Linseed oil-based (ELO/PI, ELO/10RD1/PI) and soybean oil-based (AESO/VDM, AESO/VDM/DMPA) polymers were obtained by cationic and radical photopolymerization reactions, respectively. In order to improve the cross-linking density of the resulting polymers, 10 mol.% of RD1 was used as a reactive diluent in the cationic photopolymerization of ELO. In parallel, VDM was used as a plasticizer in AESO radical photopolymerization reactions. Positron annihilation lifetime spectroscopy (PALS) was used to characterize vegetable oil-based UV-cured polymers regarding their structural stability in a wide range of temperatures (120-320 K) and humidity. The polymers were used as laccase immobilization matrixes for the construction of amperometric biosensors. A direct dependence of the main operational parameters of the biosensors and microscopical characteristics of polymer matrixes (mostly on the size of free volumes and water content) was established. The biosensors are intended for the detection of trace water pollution with xenobiotics, carcinogenic substances with a very negative impact on human health. These findings will allow better predictions for novel polymers as immobilization matrixes for biosensing or biotechnology applications.

Impacts of Gestational FireMaster 550 Exposure on the Neonatal Cortex Are Sex Specific and Largely Attributable to the Organophosphate Esters

INTRODUCTION

Flame retardants (FRs) are common bodily and environmental pollutants, creating concern about their potential toxicity. We and others have found that the commercial mixture FireMaster® 550 (FM 550) or its individual brominated (BFR) and organophosphate ester (OPFR) components are potential developmental neurotoxicants. Using Wistar rats, we previously reported that developmental exposure to FM 550 or its component classes produced sex- and compound-specific effects on adult socioemotional behaviors. The underlying mechanisms driving the behavioral phenotypes are unknown.

METHODS

To further mechanistic understanding, here we conducted transcriptomics in parallel with a novel lipidomics approach using cortical tissues from newborn siblings of the rats in the published behavioral study. Inclusion of lipid composition is significant because it is rarely examined in developmental neurotoxicity studies. Pups were gestationally exposed via oral dosing to the dam to FM 550 or the BFR or OPFR components at environmentally relevant doses.

RESULTS

The neonatal cortex was highly sexually dimorphic in lipid and transcriptome composition, and males were more significantly impacted by FR exposure. Multiple adverse modes of action for the BFRs and OPFRs on neurodevelopment were identified, with the OPFRs being more disruptive than the BFRs via multiple mechanisms including dysregulation of mitochondrial function and disruption of cholinergic and glutamatergic systems. Disrupted mitochondrial function by environmental factors has been linked to a higher risk of autism spectrum disorders and neurodegenerative disorders. Impacted lipid classes included ceramides, sphingomyelins, and triacylglycerides. Robust ceramide upregulation in the OPFR females could suggest a heightened risk of brain metabolic disease.

CONCLUSIONS

This study reveals multiple mechanisms by which the components of a common FR mixture are developmentally neurotoxic and that the OPFRs may be the compounds of greatest concern.

Early programming of reproductive health and fertility: novel neuroendocrine mechanisms and implications in reproductive medicine

BACKGROUND

According to the Developmental Origins of Health and Disease (DOHaD) hypothesis, environmental changes taking place during early maturational periods may alter normal development and predispose to the occurrence of diverse pathologies later in life. Indeed, adverse conditions during these critical developmental windows of high plasticity have been reported to alter the offspring developmental trajectory, causing permanent functional and structural perturbations that in the long term may enhance disease susceptibility. However, while solid evidence has documented that fluctuations in environmental factors, ranging from nutrient availability to chemicals, in early developmental stages (including the peri-conceptional period) have discernible programming effects that increase vulnerability to develop metabolic perturbations, the impact and eventual mechanisms involved, of such developmental alterations on the reproductive phenotype of offspring have received less attention.

OBJECTIVE AND RATIONALE

This review will summarize recent advances in basic and clinical research that support the concept of DOHaD in the context of the impact of nutritional and hormonal perturbations, occurring during the periconceptional, fetal and early postnatal stages, on different aspects of reproductive function in both sexes. Special emphasis will be given to the effects of early nutritional stress on the timing of puberty and adult gonadotropic function, and to address the underlying neuroendocrine pathways, with particular attention to involvement of the Kiss1 system in these reproductive perturbations. The implications of such phenomena in terms of reproductive medicine will also be considered.

SEARCH METHODS

A comprehensive MEDLINE search, using PubMed as main interface, of research articles and reviews, published mainly between 2006 and 2021, has been carried out. Search was implemented using multiple terms, focusing on clinical and preclinical data from DOHaD studies, addressing periconceptional, gestational and perinatal programming of reproduction. Selected studies addressing early programming of metabolic function have also been considered, when relevant.

OUTCOMES

A solid body of evidence, from clinical and preclinical studies, has documented the impact of nutritional and hormonal fluctuations during the periconceptional, prenatal and early postnatal periods on pubertal maturation, as well as adult gonadotropic function and fertility. Furthermore, exposure to environmental chemicals, such as bisphenol A, and maternal stress has been shown to negatively influence pubertal development and gonadotropic function in adulthood. The underlying neuroendocrine pathways and mechanisms involved have been also addressed, mainly by preclinical studies, which have identified an, as yet incomplete, array of molecular and neurohormonal effectors. These include, prominently, epigenetic regulatory mechanisms and the hypothalamic Kiss1 system, which likely contribute to the generation of reproductive alterations in conditions of early nutritional and/or metabolic stress. In addition to the Kiss1 system, other major hypothalamic regulators of GnRH neurosecretion, such as γ-aminobutyric acid and glutamate, may be targets of developmental programming.

WIDER IMPLICATIONS

This review addresses an underdeveloped area of reproductive biology and medicine that may help to improve our understanding of human reproductive disorders and stresses the importance, and eventual pathogenic impact, of early determinants of puberty, adult reproductive function and fertility.

Effects of perinatal exposure to endocrine-disrupting chemicals on the reproductive system of F3 generation male rodents: a meta-analysis

To explore the relationship between perinatal exposure to endocrine-disrupting chemicals and the male reproductive system of F3 generation, and to evaluate the toxicological effects of endocrine-disrupting chemicals on the reproductive system of F3 generation male rodents. PubMed and Web of Science databases were searched to obtain the studies; overall risk ratios (RRs) with 95% confidence intervals (95% CIs) were used to evaluate the relationship between exposure to endocrine-disrupting chemicals and reproductive system damage in F3 generation male rodents. Nine studies were included for analysis. Endocrine-disrupting chemicals are significantly associated with the reproductive system of male rodents of F3 generation, especially the testis (RR = 3.13, 95% CI: 2.05, 4.76), prostate (RR = 2.26, 95% CI: 1.27, 4.00), and kidney (RR = 2.83, 95% CI: 1.77, 4.52), but the current analysis does not prove that EDCs are the adverse factors for puberty abnormalities. The results indicated that the overall associations between atrazine (RR = 3.06, 95% CI: 1.10, 8.51, P = 0.032), DDT (RR = 6.26, 95% CI: 1.56, 25.08, P = 0.010), pesticide and insect repellent mixture (permethrin and DEET) (RR = 2.23, 95% CI: 1.34, 3.69, P = 0.002), and vinclozolin (RR = 4.71, 95% CI: 2.74, 8.10, P = 0.000) and reproductive system damage in F3 generation male rodents were statistically significant. Our study indicated that EDCs have an atavistic effect on the male reproductive system, and we should pay attention to the long-term effects of environmental exposure to endocrine disruptors in future generations.

Microplastics and Their Impact on Reproduction-Can we Learn From the C. elegans Model?

Biologically active environmental pollutants have significant impact on ecosystems, wildlife, and human health. Microplastic (MP) and nanoplastic (NP) particles are pollutants that are present in the terrestrial and aquatic ecosystems at virtually every level of the food chain. Moreover, recently, airborne microplastic particles have been shown to reach and potentially damage respiratory systems. Microplastics and nanoplastics have been shown to cause increased oxidative stress, inflammation, altered metabolism leading to cellular damage, which ultimately affects tissue and organismal homeostasis in numerous animal species and human cells. However, the full impact of these plastic particles on living organisms is not completely understood. The ability of MPs/NPs to carry contaminants, toxic chemicals, pesticides, and bioactive compounds, such as endocrine disrupting chemicals, present an additional risk to animal and human health. This review will discusses the current knowledge on pathways by which microplastic and nanoplastic particles impact reproduction and reproductive behaviors from the level of the whole organism down to plastics-induced cellular defects, while also identifying gaps in current knowledge regarding mechanisms of action. Furthermore, we suggest that the nematode Caenorhabditis elegans provides an advantageous high-throughput model system for determining the effect of plastic particles on animal reproduction, using reproductive behavioral end points and cellular readouts.

Altered uterine angiogenesis in rats treated with a glyphosate-based herbicide

Glyphosate-based herbicides (GBHs) are the agrochemicals most used around the globe. However, they might have adverse effects on human and animal health. Previously, we showed that female rats neonatally exposed to GBHs exhibit altered expression of morphogenetic molecules and biomarkers of uterine development. We also observed a reduction in the size of implantation sites, altered expression of decidualization-related molecules, and increased post-implantation losses. Since decidualization comprises morphogenetic, biochemical and vascular changes, here we investigated the effects of neonatal GBH exposure on uterine angiogenesis in neonatal and pregnant rats. To achieve this, Wistar female rats were exposed to saline solution or GBH (2 mg glyphosate/kg-bw/day) on post-natal days (PND) 1, 3, 5 and 7. On PND8, uterine samples were collected for developmental studies. On PND90, the remaining females were mated and in the morning of gestational day (GD) 9, the implantation sites were collected. Angiogenesis-related molecules and cells involved in this process were identified and/or measured by immunohistochemistry or RT-PCR. On PND8, GBH-treated rats showed increased vascular endothelial growth factor (VEGF) expression and decreased Notch1, inducible nitric oxide synthase (iNOS) and Angiopoietin-2 (Ang2) mRNA levels. Vascular area, vessel diameter, endothelial cell proliferation, VEGF and Nestin protein expression, and VEGF, Notch1, iNOS and cyclooxygenase-2 (Cox-2) genes were downregulated in implantation sites of exposed females, while Ang2, VEGF receptor 1 and interleukin-10 (IL-10) were increased. Mast cells and macrophages were increased on PND8 and GD9 of treated rats. The increased Transforming growth factor-beta expression in the antimesometrial zone and IL-10 mRNA expression suggest that the M2 type is the predominant population of macrophages on implantation sites. In conclusion, neonatal GBH exposure alters the expression of angiogenesis-related molecules at neonatal uterine development and decidual reaction, suggesting altered vascular support. These alterations might contribute to the increased post-implantation losses observed in GBH-treated rats.

EDCs trigger immune-neurotransmitter related gene expression, and cause histological damage in sensitive mud crab Macrophthalmus japonicus gills and hepatopancreas

Endocrine-disrupting chemicals (EDCs), distributed at various concentrations in freshwater and marine ecosystems, affect the survival, reproduction, and behavior of wide ranges organisms. Most toxicology studies on EDCs have focused on the endocrine system of invertebrates, and research on invertebrate neurotransmitters is limited. In the present study, we investigated the expression of Macrophthalmus japonicus genes encoding γ-aminobutyric acid transporter subtype 2 (GAT-2) and glutamine synthetase (GS), which play important roles as neurotransmitters at synapses. We observed differences in the mRNA expression levels of GAT-2 and GS as well as histological changes in various tissues after exposure to bisphenol-A (BPA) and di-(2-ethylhexyl) phthalate (DEHP). The amino acid sequences of M. japonicus GAT-2 and GS formed separate branches in crustaceans, fish, insects, and mammals. M. japonicus GAT-2 and GS expression levels were highest in the gills, hepatopancreas, and stomach, and showed different between DEHP or BPA treatments. In particular, hepatopancreas GS expression on Day 1, the first step in the presynaptic process, was upregulated after BPA and DEHP exposure, while GAT-2, sequential step in the presynaptic process, was significantly elevated only in DEHP. After BPA treatments, gill GS expression was increased at all concentrations, whereas GAT-2 expression was overall down regulations. In contrast, in DEHP treatment groups hepatopancreatic GS and GAT-2 expression at Day 1 was only significantly higher and all groups including gill GS and GAT-2 expression were downregulation. Histological changes in the gills and hepatopancreas were observed in a concentration-dependent manner. Accordingly, BPA and DEHP exposure in crabs could be stimulate neurotransmitter gene expression and alter the morphological structure of gill and hepatopancreas.

Neighborhood deprivation increases the risk of Post-induction cesarean delivery

OBJECTIVE

The purpose of this study was to measure the association between neighborhood deprivation and cesarean delivery following labor induction among people delivering at term (≥37 weeks of gestation).

MATERIALS AND METHODS

We conducted a retrospective cohort study of people ≥37 weeks of gestation, with a live, singleton gestation, who underwent labor induction from 2010 to 2017 at Penn Medicine. We excluded people with a prior cesarean delivery and those with missing geocoding information. Our primary exposure was a nationally validated Area Deprivation Index with scores ranging from 1 to 100 (least to most deprived). We used a generalized linear mixed model to calculate the odds of postinduction cesarean delivery among people in 4 equally-spaced levels of neighborhood deprivation. We also conducted a sensitivity analysis with residential mobility.

RESULTS

Our cohort contained 8672 people receiving an induction at Penn Medicine. After adjustment for confounders, we found that people living in the most deprived neighborhoods were at a 29% increased risk of post-induction cesarean delivery (adjusted odds ratio = 1.29, 95% confidence interval, 1.05-1.57) compared to the least deprived. In a sensitivity analysis, including residential mobility seemed to magnify the effect sizes of the association between neighborhood deprivation and postinduction cesarean delivery, but this information was only available for a subset of people.

CONCLUSIONS

People living in neighborhoods with higher deprivation had higher odds of postinduction cesarean delivery compared to people living in less deprived neighborhoods. This work represents an important first step in understanding the impact of disadvantaged neighborhoods on adverse delivery outcomes.

Analysis and Quantification of Alkyl (C12-22) Trimethyl Ammonium Chloride Content in Cosmetics: Regulatory Compliance Gap Analysis

Background: Exceeding the recommended Alkyl (C12-22) trimethyl ammonium bromide and chloride levels in cosmetics and personal care products is a serious health threat. Objectives: To quantify and investigate Cetrimonium chloride and Behentrimonium chloride in cosmetics and personal care products in the UAE market to gauge whether or not they adhered to requirements for safety and health. Methods: A total of 164 cosmetics products were collected and analyzed in this study. The gas chromatography–mass spectrometry (GC–MS) method was developed and validated for the determination of Cetrimonium chloride and Behentrimonium chloride surfactants in cosmetics products. With each product, Cetrimonium chloride and Behentrimonium chloride (%) were calculated. To test cross-group differences in Cetrimonium chloride and Behentrimonium chloride (%), Kruskal–Wallis test was applied. Results: Of the 125 tested cosmetics and personal care products, five (4%) exceeded the recommended Cetrimonium chloride level in rinse-off hair products (2.5%), 10 (8%) exceeded the recommended Cetrimonium chloride level in leave-on hair products (1%), and 24 (61.5%) exceeded the recommended Cetrimonium chloride level used as a preservative in cosmetics products. Moreover, of the 125 tested cosmetics and personal care products, 21 (53.8%) exceeded the recommended Behentrimonium chloride level used as preservatives in cosmetics products. Conclusions: Although several structures for cosmetics quality and control across the globe are fairly comprehensive and intricate, there is a need to make them more rigorous to apply compliance with GMP and ensure regulatory control. Doing so would help enhance the inspection and regulation of cosmetics containing Behentrimonium chloride/Cetrimonium chloride preservatives. Furthermore, there is a dire need to establish a unified cosmetovigilance worldwide.

FireMaster® 550 (FM 550) exposure during the perinatal period impacts partner preference behavior and nucleus accumbens core medium spiny neuron electrophysiology in adult male and female prairie voles, Microtus ochrogaster

One of the most widely used flame retardant (FR) mixtures in household products is Firemaster 550 (FM 550). FM 550 leaches from items such as foam-based furniture and infant products, resulting in contamination of the household environment and biota. Previous studies indicate sex-specific behavioral deficits in rodents and zebrafish in response to developmental FM 550 exposure. These deficits include impacts on social and attachment behaviors in a prosocial rodent: the prairie vole (Microtus ochrogaster). The prairie vole is a laboratory-acclimated rodent that exhibits spontaneous attachment behaviors including pair bonding. Here we extend previous work by addressing how developmental exposure to FM 550 impacts pair bonding strength via an extended-time partner preference test, as well as neuron electrophysiological properties in a region implicated in pair bond behavior, the nucleus accumbens (NAcc) core. Dams were exposed to vehicle or 1000 μg of FM 550 via subcutaneous injections throughout gestation, and female and male pups were directly exposed beginning the day after birth until weaning. Pair bond behavior of adult female and male offspring was assessed using a three hour-long partner preference test. Afterwards, acute brain slices of the NAcc core were produced and medium spiny neuron electrophysiological attributes recorded via whole cell patch-clamp. Behavioral impacts were sex-specific. Partner preference behavior was increased in exposed females but decreased in exposed males. Electrophysiological impacts were similar between sexes and specific to attributes related to input resistance. Input resistance was decreased in neurons recorded from both sexes exposed to FM 550 compared to vehicle. This study supports the hypothesis that developmental exposure to FM 550 impacts attachment behaviors and demonstrates a novel FM 550 effect on neural electrophysiology.

Impacts of brewing time, brewing temperature and brands on the leaching of phthalates and bisphenol A in dry tea

Although tea is often considered a healthy drink, there is the possibility for it to contain bisphenol A and phthalates. This project was designed to quantitate the amount of these compounds when tea was prepared in a variety of conditions, and with a variety of different brands and flavours. BPA and phthalates were extracted using solid phase extraction and quantitated using gas chromatography - mass spectrometry. The leaching concentration of di-n-butyl phthalate, a major phthalate in dry tea samples, increased with respect to both brewing time and temperature at rates of 5.9 ng/g/min and 2.3 ng/g/°C, respectively. Loose leaf green teas showed lower concentrations of contaminants than bagged teas. The highest concentrations found of all compounds were for benzylbutyl phthalate in both Brand2 English breakfast and Brand2 green teas with concentrations of 244 ± 76 ng/g and 197 ± 9 ng/g, respectively. Di-n-butyl phthalate, benzylbutyl phthalate and bis-2-ethylhexyl phthalate were all present in concentrations of 50 ng/g or more in 3 or more samples.

Endocrine disrupting chemicals (EDCs) and the neuroendocrine system: Beyond estrogen, androgen, and thyroid

Hundreds of anthropogenic chemicals occupy our bodies, a situation that threatens the health of present and future generations. This chapter focuses on endocrine disrupting compounds (EDCs), both naturally occurring and man-made, that affect the neuroendocrine system to adversely impact health, with an emphasis on reproductive and metabolic pathways. The neuroendocrine system is highly sexually dimorphic and essential for maintaining homeostasis and appropriately responding to the environment. Comprising both neural and endocrine components, the neuroendocrine system is hormone sensitive throughout life and touches every organ system in the body. The integrative nature of the neuroendocrine system means that EDCs can have multi-system effects. Additionally, because gonadal hormones are essential for the sex-specific organization of numerous neuroendocrine pathways, endocrine disruption of this programming can lead to permanent deficits. Included in this review is a brief history of the neuroendocrine disruption field and a thorough discussion of the most common and less well understood neuroendocrine disruption modes of action. Also provided are extensive examples of how EDCs are likely contributing to neuroendocrine disorders such as obesity, and evidence that they have the potential for multi-generational effects.

Post-Translational Modifications in Oocyte Maturation and Embryo Development

Mammalian oocyte maturation and embryo development are unique biological processes regulated by various modifications. Since de novo mRNA transcription is absent during oocyte meiosis, protein-level regulation, especially post-translational modification (PTM), is crucial. It is known that PTM plays key roles in diverse cellular events such as DNA damage response, chromosome condensation, and cytoskeletal organization during oocyte maturation and embryo development. However, most previous reviews on PTM in oocytes and embryos have only focused on studies of Xenopus laevis or Caenorhabditis elegans eggs. In this review, we will discuss the latest discoveries regarding PTM in mammalian oocytes maturation and embryo development, focusing on phosphorylation, ubiquitination, SUMOylation and Poly(ADP-ribosyl)ation (PARylation). Phosphorylation functions in chromosome condensation and spindle alignment by regulating histone H3, mitogen-activated protein kinases, and some other pathways during mammalian oocyte maturation. Ubiquitination is a three-step enzymatic cascade that facilitates the degradation of proteins, and numerous E3 ubiquitin ligases are involved in modifying substrates and thus regulating oocyte maturation, oocyte-sperm binding, and early embryo development. Through the reversible addition and removal of SUMO (small ubiquitin-related modifier) on lysine residues, SUMOylation affects the cell cycle and DNA damage response in oocytes. As an emerging PTM, PARlation has been shown to not only participate in DNA damage repair, but also mediate asymmetric division of oocyte meiosis. Each of these PTMs and external environments is versatile and contributes to distinct phases during oocyte maturation and embryo development.

Endocrine disrupting chemicals: strategies to protect present and future generations

Introduction: Endocrine-disrupting chemicals (EDCs) are chemicals that alter the actions of hormones. In the 21^st Century, numerous expert groups of clinicians, scientists, and environmental activists have called for action to protect present and future generations from the harm induced by EDC exposures. These demands for regulatory responses come because of the strong weight of the evidence from epidemiology, wildlife, and controlled laboratory studies.Areas covered: In this review, we examine the conclusions drawn by experts from different scientific and medical disciplines. We also address several areas where recent findings or work has changed the landscape of EDC work including new approaches to identify and evaluate the evidence for EDCs using a key characteristics approach, the need to expand our understanding of vulnerable periods of development, and the increasing concern that traditional methods used to evaluate toxicity of environmental chemicals are insufficient for EDCs and how collaborative science could help to address these gaps.Expert opinion: The science is clear: there is more than enough evidence to demonstrate that EDCs affect the health of humans and wildlife. Waiting to act is a decision that puts the health of current and future generations at risk.

Maternal Exposure to Dibutyl Phthalate (DBP) or Diethylstilbestrol (DES) Leads to Long-Term Changes in Hypothalamic Gene Expression and Sexual Behavior

Xenobiotic exposure during pregnancy and lactation has been linked to perinatal changes in male reproductive outcomes and other endocrine parameters. This pilot study wished to assess whether brief maternal exposure of rats to xenobiotics dibutyl phthalate (DBP) or diethylstilbestrol (DES) might also cause long-term changes in hypothalamic gene expression or in reproductive behavior of the resulting offspring. Time-mated female Sprague Dawley rats were given either DBP (500 mg/kg body weight, every second day from GD14.5 to PND6), DES (125 µg/kg body weight at GD14.5 and GD16.5 only), or vehicle (n = 8–12 per group) and mild endocrine disruption was confirmed by monitoring postnatal anogenital distance. Hypothalamic RNA from male and female offspring at PND10, PND24 and PND90 was analyzed by qRT-PCR for expression of aromatase, oxytocin, vasopressin, ER-alpha, ER-beta, kisspeptin, and GnRH genes. Reproductive behavior was monitored in male and female offspring from PND60 to PND90. Particularly, DES treatment led to significant changes in hypothalamic gene expression, which for the oxytocin gene was still evident at PND90, as well as in sexual behavior. In conclusion, maternal xenobiotic exposure may not only alter endocrine systems in offspring but, by impacting on brain development at a critical time, can have long-term effects on male or female sexual behavior.

Modulation of Human Sperm Mitochondrial Respiration Efficiency by Plant Polyphenols

Plant bioactives, such as polyphenols, can differentially affect (positively or negatively) sperm quality, depending on their concentration. These molecules have been proposed as natural scavengers of reactive oxygen species (ROS) for male infertility treatment. However, few data are available about their effects on the molecular mechanisms related to sperm quality and, in particular, to sperm mitochondrial function. We investigated the effects of quercetin, naringenin, genistein, apigenin, luteolin, and resveratrol at the concentration of 0.1-1000 nM on mitochondrial respiration efficiency. Upon chemical exposure, spermatozoa were swollen in a hypotonic solution and used for polarographic assays of mitochondrial respiration. All tested compounds, except for apigenin, caused a significant increase in the mitochondrial respiration efficiency at the concentration of 0.1 nM, and a significant decrease starting from concentrations of 10 nM. The analysis of oxygen consumption rate in the active and in the resting state of mitochondrial respiration suggested different mechanisms by which the tested compounds modulate mitochondrial function. Therefore, by virtue of their ability to stimulate the respiration active state, quercetin, genistein, and luteolin were found to improve mitochondrial function in asthenozoospermic samples. Our results are relevant to the debate on the promises and perils of natural antioxidants in nutraceutical supplementation.

Cellular and molecular features of EDC exposure: consequences for the GnRH network

The onset of puberty and the female ovulatory cycle are important developmental milestones of the reproductive system. These processes are controlled by a tightly organized network of neurotransmitters and neuropeptides, as well as genetic, epigenetic and hormonal factors, which ultimately drive the pulsatile secretion of gonadotropin-releasing hormone. They also strongly depend on organizational processes that take place during fetal and early postnatal life. Therefore, exposure to environmental pollutants such as endocrine-disrupting chemicals (EDCs) during critical periods of development can result in altered brain development, delayed or advanced puberty and long-term reproductive consequences, such as impaired fertility. The gonads and peripheral organs are targets of EDCs, and research from the past few years suggests that the organization of the neuroendocrine control of reproduction is also sensitive to environmental cues and disruption. Among other mechanisms, EDCs interfere with the action of steroidal and non-steroidal receptors, and alter enzymatic, metabolic and epigenetic pathways during development. In this Review, we discuss the cellular and molecular consequences of perinatal exposure (mostly in rodents) to representative EDCs with a focus on the neuroendocrine control of reproduction, pubertal timing and the female ovulatory cycle.

Cross-species physiological interactions of endocrine disrupting chemicals with the circadian clock

Endocrine disrupting chemicals (EDCs) are endocrine-active chemical pollutants that disrupt reproductive, neuroendocrine, cardiovascular and metabolic health across species. The circadian clock is a transcriptional oscillator responsible for entraining 24-hour rhythms of physiology, behavior and metabolism. Extensive bidirectional cross talk exists between circadian and endocrine systems and circadian rhythmicity is present at all levels of endocrine control, from synthesis and release of hormones, to sensitivity of target tissues to hormone action. In mammals, a range of hormones directly alter clock gene expression and circadian physiology via nuclear receptor (NR) binding and subsequent genomic action, modulating physiological processes such as nutrient and energy metabolism, stress response, reproductive physiology and circadian behavioral rhythms. The potential for EDCs to perturb circadian clocks or circadian-driven physiology is not well characterized. For this reason, we explore evidence for parallel endocrine and circadian disruption following EDC exposure across species. In the reviewed studies, EDCs dysregulated core clock and circadian rhythm network gene expression in brain and peripheral organs, and altered circadian reproductive, behavioral and metabolic rhythms. Circadian impacts occurred in parallel to endocrine and metabolic alterations such as impaired fertility and dysregulated metabolic and energetic homeostasis. Further research is warranted to understand the nature of interaction between circadian and endocrine systems in mediating physiological effects of EDC exposure at environmental levels.

Perinatal exposure to FireMaster® 550 (FM550), brominated or organophosphate flame retardants produces sex and compound specific effects on adult Wistar rat socioemotional behavior

Firemaster 550 (FM550) is a flame retardant (FR) mixture that has become one of the most commonly used FRs in household items such as foam-based furniture and baby products. Because this mixture readily leaches from products, contamination of the environment and human tissues is widespread. Prior work by us and others has reported sex-specific behavioral deficits in rodents and zebrafish following early life exposure. In an effort to understand the mechanisms by which these behavioral effects occur, here we explored the effects of its constituents on behavioral outcomes previously shown to be altered by developmental FM550 exposure. The FM550 commercial mixture is composed of two brominated compounds (BFR) and two organophosphate compounds (OPFRs) at almost equivalent proportions. Both the BFR and the OPFR components are differentially metabolized and structurally distinct, but similar to known neurotoxicants. Here we examined adult Wistar rat offspring socioemotional behaviors following perinatal exposure (oral, to the dam) to vehicle, 2000 μg/day FM550, 1000 μg/day BFR or 1000 μg/day OPFR from gestation day 0 to weaning. Beginning on postnatal day 65 offspring from all groups were subjected to a series of behavioral tasks including open field, elevated plus maze, marble burying, social interaction tests, and running wheel. Effects were exposure-, sex- and task-specific, with BFR exposure resulting in the most consistent behavioral deficits. Overall, exposed females showed more deficits compared to males across all dose groups and tasks. These findings help elucidate how different classes of flame retardants, independently and as a mixture, contribute to sex-specific behavioral effects of exposure.

Global trends in pesticides: A looming threat and viable alternatives

Pesticides are widely used chemical compounds in agriculture to destroy insects, pests and weeds. In modern era, they form an indispensable part of agricultural and health practices. Globally, nearly 3 billion kg of pesticides are used every year with a budget of ~40 billion USD. This extensive usage has increased the crop yield as well as led to significant reduction in harvest losses and thereby, enhanced food availability. On the other hand, indiscriminate usage of these chemicals has led to several environmental implications and caused adverse effects on human health. Epidemiological evidences have revealed the harmful effects of pesticides exposure on various organs including liver, brain, lungs and colon. Recent investigations have shown that pesticides can also lead to fatal consequences such as cancer among individuals. These chemicals enter ecosystem, thus hampering the sensitive environmental equilibrium through bio-accumulation. Due to their non-biodegradable nature, they can persist in nature for years and are regarded as potent biohazard. Worldwide, very few surveillance methods have been considered, which can bring awareness among the individuals, therefore the present review is an attempt to delineate consequences induced by various types of pesticide exposure on the environment. Further, the prospective of biopesticides use could facilitate the increase of crop production without compromising human health.

Occurrence and distribution of microplastics-sorbed phthalic acid esters (PAEs) in coastal psammitic sediments of tropical Atlantic Ocean, Gulf of Guinea

Baseline microplastic pollution and the occurrence, spatial distribution and ecological risk of microplastic-sorbed phthalate esters (PAEs) in littoral sandflat sediments of the Gulf of Guinea were investigated. A total of 150 sediment samples were collected using a 0.5 × 0.5 × 0.2 m quadrant placed along designated high, drift and current waterlines at five (5) beaches. Analysis for 6 PAEs-sorbed to microplastics (MPs) was carried out using gas chromatography - mass spectrometry (GC-MS). Microplastic particles (1-5 mm) were identified visually and FTIR spectroscopy was also used for identification. The MPs distribution was variably heterogenous with a total of 3424 particles per m² found within the drift and high waterlines across all sites. Results indicated fragments as the dominant microplastic type compared to pellets and fibres. Polyethylene terephthalate was the major polymer type and accounted for a weighted average of 41% of the total plastics, followed by polystyrene (28%), and polypropylene (21%). The ∑₆PAEs concentration ranged from BDL to 164.09 mg/kg dw, dominated by di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DnBP), and dimethyl phthalate. The preliminary ecological risk assessment of PAEs in the microplastic fraction, RQ_mp, showed DEHP and DnBP may present medium to high biological risks to marine organisms, suggesting that future study of PAEs in total sediment versus the MP fraction might be useful to refine ecological risk assessments. Land-based anthropogenic activities are primary sources of MPs, whereas oceanographic peculiarities of the area constitute the major distribution driving force.

A fluorescent amplification strategy for high-sensitive detection of 17 β-estradiol based on EXPAR and HCR

Environmental endocrine disruptors in the environment and food, especially 17 β-estradiol (E2), are important factors affecting the growth and development of organisms. In this research, we constructed a fluorescence strategy for two-step amplification that combined two currently popular methods, exponential amplification reaction (EXPAR) and hybridization chain reaction (HCR). E2 competed with the complementary DNA (cDNA) to bind the aptamer modified on the magnetic beads. The free complementary strand in the supernatant was used as a trigger sequence to activate EXPAR, producing a large amount of short single-stranded DNA (ssDNA). The amplified ssDNA can trigger the second HCR amplification, producing many long double-stranded DNA (dsDNA) analogues. According to the principle of fluorescence resonance energy transfer, the carboxyfluorescein (FAM) signals in H1 and H2 hairpins were quenched by black hole quencher (BHQ-1). After the addition of E2 and initiation of amplification, the initially quenched fluorescent signal would be restored. This strategy with a detection limit of 0.37 pg mL^-1 (S/N = 3) showed a good linear relationship in the range of 0.4-800 pg mL^-1. In addition, the recovery rates of the method for milk and water samples were 98.55%-116.95% and 92.32%-107.00%, respectively. This is the first report of the combined detection of EXPAR and HCR, providing a reference for rapid and highly sensitive detection using multiple isothermal amplification methods.

Microwave-assisted rapid degradation of DDT using nanohybrids of PANI with SnO2 derived from Psidium Guajava extract

The present work reports microwave-assisted synthesis of SnO₂ nanoparticles via green route using Psidium Guajava extract. For the enhancement of catalytic activity, nanohybrids of SnO₂ were formulated using different ratios of polyaniline (PANI) via ultrasound-assisted chemical polymerization. Formation of nanohybrids was confirmed via IR and XPS studies. The UV-vis DRS spectra of PANI/SnO₂ revealed significant reduction in the optical band gap upon nanohybrid formation. Microwave-assisted catalytic efficiency of pure SnO₂, PANI, PANI/SnO₂ nanohybrids was investigated using DDT as a model persistent organic pollutant. The degradation efficiency of PANI/SnO₂ was found to increase with the increase in the loading of PANI. Around 87% of DDT degradation was achieved within a very short period of 12 min under microwave irradiation using PANI/SnO₂-50/50 as catalyst. The effect of DDT concentration was explored and the degradation efficiency of PANI/SnO₂-50/50 catalyst was noticed to be as high as 82% in presence of 100 mg/L of DDT. The effect of microwave power on the degradation efficiency revealed 79% degradation using the same nanohybrid when exposed to microwave irradiation for 5 min under 1110 W microwave power. Scavenging studies confirmed the generation of OH, O₂^- radicals. The fragments with m/z values as low as 86 and 70 were confirmed by LCMS analysis. Recyclability tests showed that PANI/SnO₂-50/50 nanohybrid exhibited 81% degradation of DDT (500 mg/L) even after the third cycle, which reflected high catalytic efficiency as well as remarkable stability of the catalyst. This green nanohybrid could therefore be effectively utilized for the rapid degradation of persistent organic pollutants.

Development of A Novel High Throughput Photo-catalyst Screening Procedure: UV-A Degradation of 17α-Ethinylestradiol with Doped TiO2-Based Photo-catalysts

The rising pollution of surface water by endocrine disruptive chemicals (EDCS) could lead to the persistent harm of aquatic wildlife. Addressing this concern, advanced waste water treatment techniques should be established in addition to the present sewage treatment. Therefore, the promising advanced oxidation process of photocatalysis is discussed. With the aim of establishing a novel high throughput screening approach for photocatalysts, a workflow resting upon the use of a self-constructed 60-fold parallel stirring UV-A LED photoreactor, followed by parallel sample extraction by SPE and sequential automated analysis by GC-MS, was developed, and is presented in this article. With the described system, TiO₂-based photocatalysts, doped with different amounts of zinc, and synthesised by a sol-gel-route, were tested regarding their activity in the photocatalytic degradation of the synthetic estrogen 17α-ethinylestradiol. Thereby, the functional behavior of the photoreactor system and its applicability in a high throughput process could be evaluated. As a result of the catalyst screening, TiO₂ catalysts with low amounts of zinc were found with a significantly higher activity, compared to undoped TiO₂. In conclusion, the presented system provides an easily accessible high throughput method for a variety of photocatalytic experiments.

Prenatal exposure to the pesticide metam sodium induces sensorimotor and neurobehavioral abnormalities in mice offspring

The present study has investigated developmental neurotoxicity of Metam sodium (MS), from gestational day 6 and throughout the gestation period until delivery. Therefore, mated female mice were orally exposed on a daily basis to 0 (control), 50, 100 or 150 mg of MS/kg of body weight and their standard fertility and reproductive parameters were assessed. The offspring were examined for their sensorimotor development, depression and cognitive performance. Our results showed that MS exposure during pregnancy led to one case of mortality, two cases of abortion and disturbed fertility and reproductive parameters in pregnant dams. In offspring, MS induced an overall delay in innate reflexes and sensorimotor performances. Furthermore, all prenatally treated animals showed an increased level of depression-like behavior as well as a pronounced cognitive impairment in adulthood. These results demonstrated that prenatal exposure to MS causes a long-lasting developmental neurotoxicity and alters a wide range of behavioral functions in mice.

Postnatal genistein administration selectively abolishes sexual dimorphism in specific hypothalamic dopaminergic system in mice

As demonstrated in previous studies, early postnatal genistein (GEN) administration to mice pups of both sexes, at doses similar to that of infant soy-based formulas, may affect the development of some steroid-sensitive neuronal circuits (i.e. nitrergic and vasopressinergic systems), causing irreversible alterations in adults. Here, we investigated the hypothalamic and mesencephalic dopaminergic system (identified with tyrosine hydroxylase immunohistochemistry). GEN administration (50 mg/kg) to mice of both sexes during the first week of postnatal life specifically affected tyrosine hydroxylase immunohistochemistry in the hypothalamic subpopulation of neurons, abolishing their sexual dimorphism. On the contrary, we did not observe any effects in the mesencephalic groups. Due to the large involvement of dopamine in circuits controlling rodent sexual behavior and food intake, these results clearly indicate that the early postnatal administration of GEN may irreversibly alter the control of reproduction, of energetic metabolism, and other behaviors. These results suggest the need for a careful evaluation of the use of soy products in both human and animal newborns.

Bisphenol-A (BPA) in Foods commonly consumed in Southwest Nigeria and its Human Health Risk

Bisphenol-A (BPA) is a synthetic chemical ubiquitous in the environment and listed as an endocrine disruptor. It has the tendency of migrating into food stored in materials containing it. This study, therefore, determines the concentrations of BPA in foods commonly consumed in Southwest Nigeria by the adult population and also estimates the risk associated with human exposure. Eight different food categories were selected for this study. Standard QuEChERS protocol was used for sample extraction and analysed using gas chromatography-mass spectrometry (GC-MS). Vegetable oil had the highest BPA concentration (28.4 ng/g). This was followed by aquatic canned fish (26.3 ng/g), canned beef (21.3 ng/g) and crayfish (17.5 ng/g). These concentrations were below the 600 ng/g limit of the European Commission for BPA in foods. Bisphenol-A was not detected in raw beef, chicken, cheese, apple, tomatoes, beans and rice; and chicken eggs. The adult population had an average dietary intake of 30.4 ng/kg bw/day. There is no likely occurrence of harmful health effects of BPA in the selected foods with respect to the current concentrations found therein. However, routine monitoring is recommended to prevent human exposure to BPA.

Sex-specific effects of perinatal FireMaster® 550 (FM 550) exposure on socioemotional behavior in prairie voles

The rapidly rising incidence of neurodevelopmental disorders with social deficits is raising concern that developmental exposure to environmental contaminants may be contributory. Firemaster 550 (FM 550) is one of the most prevalent flame-retardant (FR) mixtures used in foam-based furniture and baby products and contains both brominated and organophosphate components. We and others have published evidence of developmental neurotoxicity and sex specific effects of FM 550 on anxiety-like and exploratory behaviors. Using a prosocial animal model, we investigated the impact of perinatal FM 550 exposure on a range of socioemotional behaviors including anxiety, attachment, and memory. Virtually unknown to toxicologists, but widely used in the behavioral neurosciences, the prairie vole (Microtus ochrogaster) is a uniquely valuable model organism for examining environmental factors on sociality because this species is spontaneously prosocial, biparental, and displays attachment behaviors including pair bonding. Dams were exposed to 0, 500, 1000, or 2000 μg of FM 550 via subcutaneous (sc) injections throughout gestation, and pups were directly exposed beginning the day after birth until weaning. Adult offspring of both sexes were then subjected to multiple tasks including open field, novel object recognition, and partner preference. Effects were dose responsive and sex-specific, with females more greatly affected. Exposure-related outcomes in females included elevated anxiety, decreased social interaction, decreased exploratory motivation, and aversion to novelty. Exposed males also had social deficits, with males in all three dose groups failing to show a partner preference. Our studies demonstrate the utility of the prairie vole for investigating the impact of chemical exposures on social behavior and support the hypothesis that developmental FR exposure impacts the social brain. Future studies will probe the possible mechanisms by which these effects arise.