Oxidative stress, biochemical, lipid peroxidation, and antioxidant responses in Clarias gariepinus exposed to acute concentrations of ivermectin

The short-term effects of ivermectin (IVMT) on the oxidative stress and biochemical parameters of Clarias gariepinus juvenile was assessed under semi-static conditions at concentrations of 9 to 25 mu g L-1 for up to 4 days. Juveniles were highly sensitive to ivermectin, with an LC50 of 15 mu g L-1.The antioxidant enzyme profile assessed included glutathione reductase (GR), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). General stress biomarkers such as serum glucose, protein, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were also determined at 24-h, 48-h, 72-h, and 96-h exposure durations. Lipid peroxidation showed significant (p < 0.05) decreases in higher concentrations (21 mu g L(-1)and 25 mu g L-1) and durations of exposure (72 h and 96 h). Significant concentration-dependent increases (p < 0.05) were recorded in the liver function enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) when compared to the control. GPx decreased significantly (p < 0.05) in higher concentrations (21 mu g L(-1)and 25 mu g L-1) and durations of exposure (48-96 h). Protein showed significant concentration-dependent decreases, while glucose recorded a mixed trend. The changes in the hepatic antioxidant enzyme activities and serum metabolites were indicative of oxidative stress induced by IVMT. This showed that IVMT is toxic to fish and should be used with utmost caution.