Etoxazole Exposure Triggers Sublethal Metabolic Responses in Earthworms (Eisenia fetida): An NMR-Based Metabolomics Study

As a highly effective acaricide, etoxazole is widely used in agricultural production, but its toxicological effects on soil organisms remain unclear. Based on nuclear magnetic resonance (NMR) metabolomics technology, in this study, we systematically investigated the sublethal responses of earthworms (<i>Eisenia fetida</i>) to etoxazole. The results showed that etoxazole exposure significantly altered the endogenous metabolic profiles in earthworms, with 19 and 20 metabolites significantly changed after 2 and 14 d of exposure, respectively. Trimethylamine N-oxide exhibited specific changes, indicating that it may be a potential biomarker for exposure to etoxazole. KEGG pathway analysis revealed that five metabolic pathways were notably affected after 2 and 14 days of etoxazole exposure. These pathways were primarily associated with energy conversion, protein and amino acid synthesis and metabolism, carbohydrate metabolism, and nucleic acid and DNA synthesis. Overall, etoxazole exposure notably altered the endogenous metabolic profiles of earthworms. This study was of great significance for comprehensively understanding the potential hazards that etoxazole poses to soil ecosystems and provides important information for environmental monitoring and ecological risk assessment.