Impacts of Voliam Flexi on Antioxidant Responses, Oxidative Stress, and Histopathological Changes in Juvenile African Catfish (Clarias gariepinus)

Abstract

This study investigated the toxicological impact of Voliam Flexi (containing chlorantraniliprole and thiamethoxam) on juvenile African catfish (Clarias gariepinus), a species commonly exposed to pesticides in rice cultivation regions. This study investigated the toxic effects of Voliam Flexi on juvenile African catfish, focusing on oxidative stress, antioxidant enzyme disruption, and tissue damage at environmentally relevant concentrations. Over a 15-day period, fish were exposed to environmentally relevant pesticide concentrations commonly applied in Egyptian rice fields, specifically 43.5, 87.5, and 175 mg/L. Antioxidant defense mechanisms, including GST (glutathione S-transferase), SOD (superoxide dismutase), CAT (catalase), and TAC (total antioxidant capacity), were measured alongside oxidative damage indicators such as lipid peroxidation (LPX) and DNA fragmentation. A dose-dependent reduction in antioxidant enzyme activity and an increase in oxidative damage were observed, with higher pesticide concentrations leading to elevated LPX levels and DNA fragmentation. Histopathological evaluations of the kidney and spleen revealed significant degenerative changes, such as tubular damage, edema, and pyknotic nuclei, particularly at higher concentrations. These findings suggest that Voliam Flexi poses considerable risks to aquatic organisms, disrupting cellular functions, and leading to tissue damage. The study highlights the potential threat of pesticide runoff to aquatic biodiversity and calls for stricter environmental regulations to mitigate these risks.