ABSTRACT This investigation evaluated the impact of different sublethal concentrations of Acid Black‐1 (AB‐1, CI: 20470) on the activity of key enzymes involved in the antioxidant defense system. Glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and glutathione S‐transferase (GST) activities were assessed in the liver, kidney, gill, muscle, and brain of Labeo rohita . The study involved a 150‐day subchronic exposure period followed by a 90‐day recovery phase. Enzyme activities in all tested tissues exhibited dose‐ and duration‐dependent changes during both exposure and recovery. Notably, GR, GPx, and SOD activities were significantly altered in all the tissues, with the most pronounced changes observed in the muscle for a majority of the enzymes. A consistent and marked decline in SOD activity throughout the study strongly suggests that repeated exposure to even minute concentrations of AB‐1 induced significant and prolonged oxidative stress. Further, the molecular docking studies indicated that AB‐1 interacted with different enzymes via either the active site or the binding site, thereby affecting the enzyme activity. Our findings indicate that AB‐1, even at the lowest concentration, elicited clear toxic effects in L. rohita . Based on these subchronic findings, SOD is proposed as a potential biomarker enzyme for AB‐1 toxicity in this fish species.
Singh et al. (Mon,) studied this question.