Integrated Biomarker Assessment of Bifenthrin, Chlorpyrifos and Endosulfan Toxicity in Indigenous Carps ( Catla catla and Labeo rohita ): Oxidative Stress, Genotoxicity and Nuclear Alterations

BACKGROUND: The extensive use of pesticides in agriculture has increased their runoff into aquatic ecosystems, posing serious risks to non-target organisms. Fish are recognized as sensitive bioindicators and are widely used to evaluate the ecological impacts of pesticide contamination. OBJECTIVE: This study investigated the acute toxic effects of bifenthrin + chlorpyrifos (B + C) and bifenthrin + endosulfan (B + E) mixtures on antioxidant enzyme activities, DNA damage and nuclear abnormalities (NAs) in Catla catla and Labeo rohita. METHODS: concentrations for 4 days, with sampling at 24-h intervals. Antioxidant enzymes, including superoxide dismutase (SOD), glutathione S-transferase (GST), peroxidase (POx) and catalase (CAT), were evaluated in different organs. Genotoxic effects were assessed through micronucleus (MN), NAs, damaged nuclei and genomic damage index (GDI) analyses. RESULTS: for C. catla and L. rohita, respectively. C. catla exhibited greater sensitivity to both mixtures. SOD and GST activities increased significantly (p < 0.05) in all organs with increasing exposure duration. POx activity generally increased with exposure time, while CAT activity increased in gills, liver and kidney but declined in brain, heart and muscle tissues. Micronuclei and other NAs increased significantly with exposure duration in both species. Genomic damage indices showed significant positive dependence on exposure duration in L. rohita. CONCLUSION: Combined exposure to bifenthrin-chlorpyrifos and bifenthrin-endosulfan mixtures induces pronounced oxidative stress and genotoxic damage in C. catla and L. rohita, highlighting the usefulness of antioxidant and DNA damage biomarkers for monitoring pesticide contamination in aquatic environments.