Assessment of ROS-Mediated Genotoxic and Systemic Responses in Fish Exposed to Pesticide Carbendazim Stress

Carbendazim (CBZ) is a widely used pesticide in global agricultural practices, and it may pose a significant risk to nontarget organisms. This study evaluates the concentration and the exposure-mediated harmful effects of CBZ on important food fish Channa striata. The lethal concentration (LC₅₀) value of pesticide CBZ was calculated as 0.330 mg/L for 96 h of exposure. A total of 45 C. striata were divided into three groups. The first group was unexposed; the other two groups were exposed in triplicate to 1/20th (0.165 mg/L) and 1/10th (0.330 mg/L) concentration of the 96-h LC₅₀ of CBZ (50% wettable powder) for 7 and 14 days. A significant increase (p < 0.05) in intracellular ROS, micronuclei frequency, and nuclear abnormalities in blood cells was noted with increasing concentration. A decline (p < 0.05) in RBC, Hb, PCV, and MCHC was observed. Conversely, marked increases (p < 0.05) in WBC, MCV, and MCH were reported in fish exposed to higher concentrations of pesticide. A significant elevation in liver (ALP, ALT, and AST) and kidney (urea, creatinine, and uric acid) biomarkers was also reported in pesticide CBZ-exposed fish. Histopathological examination revealed a dose-dependent degenerative, necrotic, and inflammatory lesion across the gill, hepatic, renal, muscular, and neural architectures. An elevation in the prevalence percentage and histological alteration indices in response to pesticide CBZ was also observed. The order of histopathological alteration indices in exposed fish was as follows: gill > liver > kidney > brain = muscle. The results revealed that the tested concentrations, being environmentally relevant and representative of potential hotspot contamination scenarios, could elicit systemic toxicity in C. striata and therefore pose a serious risk to aquatic organisms.