Journal of Xenobiotics

A significant and persistent issue in assisted reproduction is recurrent implantation failure (RIF), which is often observed even after the transfer of embryos of high morphological and/or genetic quality. Accumulating data suggest that exposure to chemicals with endocrine-disrupting effects (EDCs) may be associated with adverse implantation outcomes. Many environmentally widespread substances have the potential to interfere with the regulation of the endocrine system, affecting critical mechanisms involved in implantation, such as endometrial receptivity, steroid hormone receptor signaling, immune tolerance at the maternal–fetal interface, and the epigenetic regulation of genes that are essential for successful implantation. Experimental studies have shown that exposure to EDCs can alter gene expression in the endometrium, inflammatory pathways, and the dynamics of early embryonic development, while clinical and epidemiological data have associated increased levels of EDCs in the body with lower implantation rates in assisted reproductive technology (ART) cycles. This narrative review examines the implications of these findings in reproductive medicine, summarizes recent experimental and clinical data, and highlights the molecular mechanisms linking exposure to endocrine disruptors with recurrent implantation failure. Recognizing environmental chemical exposure as a potentially modifiable risk factor may offer new perspectives for the prevention of RIF and the development of more personalized therapeutic strategies.

Oxidative and nitrosative stress are central mechanisms in the pathogenesis of neurodegenerative diseases, where excessive production of reactive oxygen and nitrogen species (ROS/RNS) leads to mitochondrial dysfunction, membrane damage, and neuronal death. In this study, we established and compared short-term (2 h) and long-term (20 h) exposure paradigms to sodium nitroprusside (SNP), used as a xenobiotic nitric oxide donor, in two neuronal cell lines (mHippoE-18 and PC12) and zebrafish larvae, aiming to provide a preclinical framework for neurodegenerative drug discovery. In vitro, SNP exposure caused concentration-dependent reductions in viability and alterations in oxidative balance, with mHippoE-18 cells exhibiting higher susceptibility than PC12 cells. In the short-term exposure paradigm, cytotoxicity was primarily associated with membrane disruption at higher concentrations, whereas oxidative stress contributed more strongly at intermediate doses. In the long-term exposure, mHippoE-18 cells showed strong integrated correlations between ROS, LDH release, and viability loss, highlighting their increased vulnerability to nitrosative stress. In zebrafish, SNP exposure impaired metabolic activity and swimming behavior in both paradigms. Long-term exposure led to consistent dose-dependent increases in ROS, accompanied by locomotor deficits tightly linked to energy metabolism. Overall, the higher sensitivity of mHippoE-18 cells compared with PC12 cells, together with the dose-dependent metabolic and behavioral impairments observed in zebrafish, indicates that cellular responses partially mirror in vivo outcomes. This integrative approach underscores the value of combining neuronal cell lines with zebrafish larvae to capture complementary aspects of SNP-induced neurotoxicity and to strengthen preclinical evaluation of candidate compounds with protective or therapeutic potential. These findings support the use of SNP as a xenobiotic model to probe nitrosative stress-driven neurotoxicity across cellular and organismal systems.

Genetic polymorphisms can modulate susceptibility to mercury (Hg) toxicity by altering metabolic and detoxification pathways. This review evaluated the association between genetic variants, Hg exposure, and obstetric outcomes. A systematic search of Scopus, PubMed and ScienceDirect through May 2025 identified 12 eligible studies (n = 4995), conducted in accordance with PRISMA guidelines, with methodological quality assessed using the Newcastle–Ottawa Scale. Meta-analysis was selectively performed only for genetically and methodologically comparable studies. The most frequently examined genes were GSTP1, GCLC, GCLM, GPX1, MT1A, ALAD, and APOE. Meta-analysis of GSTP1 rs1695, showed no statistically significant association between the Val105 allele and hair mercury concentrations (MD = −0.08 µg/g; 95% CI: −0.18 to 0.02; p = 0.13), although the direction of effect suggested a potential protective trend. Polymorphisms in other glutathione-related genes (GCLC, GCLM, and GPX1) were consistently associated with increased risks of small-for-gestational-age infants, preeclampsia, and impaired neurodevelopmental outcomes in offspring. In contrast, the APOE ε4 allele appeared to be associated with reduced fetal mercury burden, whereas polymorphisms in ALAD and MT1A were linked to higher mercury levels and adverse pregnancy-related outcomes. By integrating epidemiological evidence with mechanistic insights within a gene–environment interaction framework, this review helps to address important gaps in the existing literature. These findings underscore the importance of incorporating genetic susceptibility into Hg risk assessment and precision-based prenatal interventions.