Binding and Activation of Estrogen-Related Receptor γ: A Novel Molecular Mechanism for the Estrogenic Disruption Effects of DDT and Its Metabolites

A review on enzymatic colorimetric assays for organophosphate and carbamate pesticides detection in water environments

To monitor pesticides, which have grown to be a significant environmental and public health concern, sensitive, selective, and economical analytical tools must be developed. With advantages including high sensitivity, quick processing, and the potential for on-site monitoring, enzymatic colourimetric assays have surfaced as a potential substitute for conventional pesticide detection, particularly for organophosphate (OPPs) and carbamate pesticide detection. The toxicological effects of pesticides on humans and the environment are examined first in this review, followed by examining the concepts and mechanisms behind enzyme activity and colourimetric methods. Besides, single and double-enzyme-mediated colourimetric techniques are also studied to detect OPPs and carbamate pesticides. Furthermore, colourimetric smartphone platforms and paper-based devices have both garnered a lot of attention. These advanced approaches offer many pesticide detection options, from high-sensitivity lab-based procedures to on-site and in-field technologies. The fourth section of this review employs newly published studies to explore the applicability of these approaches for onsite OPPs and carbamate pesticide detection. Lastly, the challenges associated with enzymatic colourimetric assays, such as matrix effects and enzyme stability, and prospects for current and future research are discussed.

Predicting estrogen receptor agonists from plastic additives across various aquatic-related species using machine learning and AlphaFold2

The absence of effective public databases greatly limits high-throughput prediction of hormonal effects mediated by nuclear receptors in aquatic organisms. In this study, we developed novel strategies for multi-species screening of estrogen receptor (ER) agonists in plastic additives using AlphaFold2. Firstly, Deep Forest (DF), artificial neural network (ANN) and conventional machine learning (ML) models were utilized to screen ERα agonists. The DF models using RDKit.Chem.Descriptors and MorganFingerprint achieved a sensitivity = 0.96, specificity > 0.99, and an F1 score > 0.95, identifying 42 plastic additives as ERα agonists. Subsequently, ERα structures for Danio rerio (Dr), Oryzias melastigma (Om), Delphinus delphis (Dd), Physeter catodon (Pc), Mytilus edulis (Me), Xenopus tropicalis (Xt), Nipponia nippon (Nn), and Aptenodytes forsteri (Af) were constructed using AlphaFold2. Except for Me ERα, most species shared two common key amino acid residues responsible for ERα activity: arginine 85 and glutamic acid 44 (aligned serial numbers in the LBD). However, aquatic-related species exhibited other three additional key residues: glycine 212, leucine 216 and phenylalanine 95 (aligned serial numbers in the LBD). The number of compounds with docking energy < -9 kcal/mol for Dr, Om, Dd, Pc, Me, Xt, Nn, and Af were 4, 8, 4, 12, 10, 13, 7, and 9, respectively. The docking energy of estrone in all species was < -9 kcal/mol, while that of bisphenol P varied greatly among different species. The combined application of ML and AlphaFold enables high-throughput evaluation of the ecotoxicity posed by emerging pollutants across multiple aquatic-related species.

Organochlorine pesticides (OCPs) residues in fruit-flavored/regular waterpipe tobacco and their post-consumption waste: estimating release into inhaled smoke

There is limited information regarding organochlorine pesticides (OCPs) residues in tobacco products found in the Iranian market, especially in various types of waterpipe tobacco. The purpose of this research was to evaluate the concentration of OCPs in various waterpipe tobacco-both fruit-flavored and regular-and compare it with cigarette tobacco. Additionally, by analyzing the OCPs levels in fresh tobacco compared to tobacco wastes, an estimate has been made for the quantity of pesticides released into smoke during consumption. Our results indicated that the average detection frequency (DF) of pesticide residues was 46% for fruit-flavored tobacco, 82% for regular tobacco, and 42% for cigarette tobacco. Hexachlorocyclohexane (HCHs) isomers were the predominant pesticides in all three types of tobacco with the mean of 43.11 ± 31.81, 89.63 ± 56.08, and 41.65 ± 35.37 ng/g for fruit-flavored tobacco, regular tobacco, and cigarette tobaccos, respectively. Both the levels and DF of pesticides in post-consumption wastes were significantly reduced compared to that in fresh tobacco (p < 0.05). For all tobacco types-fruit-flavored, regular, and cigarette-notable OCPs residues were released into the gas phase, with cigarette tobacco having the highest rate at approximately ~ 37% because of greater combustion temperatures. The research points out some limitations, particularly the disregard for bowl water and charcoal as elements of waterpipe waste, which could lead to an overestimation of pesticide levels in inhaled smoke. Further studies are needed on the environmental impact of tobacco wastes and promoting for better waste management practices as well as public awareness.

Perfluorobutanoic acid: A short-chain perfluoroalkyl substance exhibiting estrogenic effects through the estrogen-related receptor γ pathways

Perfluorobutanoic acid (PFBA) is an emerging contaminant that was demonstrated to exhibit estrogen effects via action on classic estrogen receptors (ERs) in a low-activity manner. The purpose of the present study is to reveal the estrogen disruption effect and mechanism of PFBA via estrogen-related receptor γ (ERRγ) pathways. In vivo experiment indicated that PFBA accumulated in zebrafish ovary and caused ovarian injury, with disturbing sex hormone levels and interfering gene expression related to estrogen synthesis and follicle regulation. In vitro, with cell proliferation assay, PFBA could promote estrogen-sensitive endometrial cancer cell Ishikawa proliferation at lowest observed effective concentrations (LOEC) 10 nM, which was close to human exposure levels. And cell proliferation was inhibited by ERRγ antagonist GSK5182. By fluorescence competitive binding assay, molecular docking and luciferase reporter gene assays, it demonstrated that PFBA could directly bind with ERRγ and activate ERRγ transcriptional activities with a LOEC of 10 nM. Furthermore, PFBA up-regulated the proliferation-related factors downstream of ERRγ and inhibited by PI3K/Akt inhibitor LY294002, which also suppressed the cell proliferation induced by PFBA. Taken together, the results revealed that PFBA had estrogen effects at the human-related exposure concentration, and demonstrated a new estrogen effects mechanism of PFBA via ERRγ pathway.

Reproductive toxicity of bisphenol A and nitro-bisphenol A in male zebrafish at environmentally relevant concentrations

Bisphenol A (BPA) is a well-known endocrine-disrupting pollutant that poses significant environmental challenges globally. However, the toxicity of nitro-BPA (NBPA), the primary transformation product of BPA, remains poorly understood. This study employs a multi-omics approach, integrating in silico and bioinformatics analyses, to investigate and compare the male reproductive toxicity of BPA and NBPA in male zebrafish exposed to environmentally relevant concentrations. After 21 days of exposure, we observed a significant increase in cumulative egg production over five days in the NBPA 200 nM group compared to pre-exposure levels. Conversely, the gonadosomatic index of NBPA 200 nM group was significantly reduced by approximately 41.65 %. Our findings indicate that the activation of ESRRγ and inhibition of NR5A2 are critical molecular initiating events linked to male reproductive toxicity. Additionally, both BPA and NBPA were found to disrupt several key events within the steroid hormone biosynthesis pathway. This disruption includes the downregulation of genes encoding cytochrome P450 (CYP450) and hydroxysteroid dehydrogenase enzymes, as well as alterations in the levels of steroid hormones such as cholesterol and 25-hydroxycholesterol. Our study identifies biomolecular targets of BPA and NBPA at environmentally relevant concentrations that induce reproductive toxicity, enhancing our understanding of NBPA toxicity and are anticipated to inform the development of effective mitigation strategies.

The role of epigenetics in women's reproductive health: the impact of environmental factors

This paper explores the significant role of epigenetics in women's reproductive health, focusing on the impact of environmental factors. It highlights the crucial link between epigenetic modifications-such as DNA methylation and histones post-translational modifications-and reproductive health issues, including infertility and pregnancy complications. The paper reviews the influence of pollutants like PM2.5, heavy metals, and endocrine disruptors on gene expression through epigenetic mechanisms, emphasizing the need for understanding how dietary, lifestyle choices, and exposure to chemicals affect gene expression and reproductive health. Future research directions include deeper investigation into epigenetics in female reproductive health and leveraging gene editing to mitigate epigenetic changes for improving IVF success rates and managing reproductive disorders.

A new insight into the mechanism of dichlorodiphenyltrichloroethane-induced hepatotoxicity based on GSDME-mediated pyroptosis

There have been persistent concerns about the safety risks associated with DDT residues in the environment. Studies have shown that exposure to DDT or its metabolites can cause various liver diseases. However, the mechanisms of liver toxicity haven't been well studied. In our current investigation, we observed that DDT triggers pyroptosis in human liver cells (HL-7702), representing a novel form of programmed cell death. Our results delineated DDT (0-100 μM) induced pyroptosis in HL-7702 cells, which was confirmed through morphological changes, lactate dehydrogenase (LDH) release, gasdermin E (GSDME) cleavage and Annexin-V/PI staining. Knockdown of GSDME reduced cell death and transferred the mode of cell death from pyroptosis to apoptosis. Notably, DDT exposure markedly increased reactive oxygen species (ROS) production, concurrent with c-Jun N-terminal kinase (JNK) phosphorylation. Intervention with a ROS inhibitor or JNK inhibitor SP600125 restored cell viability and hindered GSDME-mediated pyroptosis. Our results firstly demonstrate that DDT suppresses HL-7702 cells growth by inducing pyroptosis mainly through the ROS/JNK/GSDME pathway. These findings not only contribute to an in-depth understanding of DDT toxicity but also open avenues for gaining valuable insights into potential mitigation strategies and therapeutic interventions.

Pesticides: An alarming detrimental to health and environment

Pesticides are chemical substances of natural or synthetic origin that are used to eradicate pests and insects. These are indispensable in the agricultural processes for better crop production. Pesticide use aims to promote crop yield and protect the crops from diseases and damage. Pesticides must be handled carefully and disposed of appropriately because they are dangerous to people and other species by default. Environmental pollution occurs when pesticide contamination spreads away from the intended plants. Older pesticides such as lindane and dichlorodiphenyltrichloroethane (DDT) may remain in water and soil for a longer time. These accumulate in various parts of the food chain and cause damage to the ecosystem. Biological techniques in the management of pest control such as importation, augmentation, and conservation, and the accompanying procedures are more efficient, less expensive, and ecologically sound than other ways. This review mainly focuses on the consequences on the targeted and non-targeted organisms including the health and well-being of humans by the use of pesticides and their toxicity. The side effects that occur when a pesticide's LD50 exceeds the accepted limit through oral or skin penetration due to their binding to various receptors such as estrogen receptors, GABA, EGFR, and others. These pesticide classes include carbamates, pyrethroids, organochlorides, organophosphorus, and others. The current study seeks to highlight the urgent requirement for a novel agricultural concept that includes a major reduction in the use of chemical pesticides.

Comparative in vitro and in silico study on the estrogenic effects of 2,2-bis(4-chlorophenyl)ethanol, 4,4'-dichlorobenzophenone and DDT analogs

DDT and its transformation products (DDTs) are frequently detected in environmental and biological media. Research suggests that DDT and its primary metabolites (DDD and DDE) could induce estrogenic effects by disturbing estrogen receptor (ER) pathways. However, the estrogenic effects of DDT high-order transformation products, and the exact mechanisms underlying the differences of responses in DDT and its metabolites (or transformation products) still remain unknown. Here, besides DDT, DDD and DDE, we selected two DDT high-order transformation products, 2,2-bis(4-chlorophenyl) ethanol (p,p'-DDOH) and 4,4'-dichlorobenzophenone (p,p'-DCBP). We aim to explore and reveal the relation between DDTs activity and their estrogenic effects by receptor binding, transcriptional activity, and ER-mediated pathways. Fluorescence assays showed that the tested 8 DDTs bound to the two isoforms (ERα and ERβ) of ER directly. Among them, p,p'-DDOH exhibited the highest binding affinity, with IC₅₀ values of 0.43 μM and 0.97 μM to ERα and ERβ, respectively. Eight DDTs showed different agonistic activity toward ER pathways, with p,p'-DDOH exhibiting the strongest potency. In silico studies revealed that the eight DDTs bound to either ERα or ERβ in a similar manner to 17β-estradiol, in which specific polar and non-polar interactions and water-mediated hydrogen bonds were involved. Furthermore, we found that 8 DDTs (0.0008-5 μM) showed distinct pro-proliferative effects on MCF-7 cells in an ER-dependent manner. Overall, our results revealed not only for the first time the estrogenic effects of two DDT high-order transformation products by acting on ER-mediated pathways, but also the molecular basis for differential activity of 8 DDTs.

Endocrine Disruptor Compounds in Environment: Focus on Women’s Reproductive Health and Endometriosis

Endometriosis is an estrogen-dependent gynecologic illness that has long-term effects on a woman’s fertility, physical health, and overall quality of life. Growing evidence suggests that endocrine-disrupting chemicals (EDCs) may be etiologically involved in the development and severity of the disease. We consider the available human evidence on EDCs and endometriosis, limiting ourselves to studies that have individually assessed chemical amounts in women. Dioxins, BPA, Phthalates, and other endocrine disruptors, like DDT, are among the evidence indicating an environmental etiology for endometriosis. Collectively, this review describes how environmental toxins are linked to lower fertility in women, as well as a number of reproductive diseases, focusing on the pathology of endometriosis and its treatments. Importantly, this review can be used to investigate techniques for preventing the negative effects of EDC exposure.