The role of gallic acid in the protection of haematological and biochemical stress induced by malathion for 96 hrs. in freshwater fish Clarias batrachus

Pesticide contamination poses a serious threat to aquatic ecosystems, particularly through organophosphate compounds that disrupt physiological functions in non-target species. This study evaluated the acute toxic effects of malathion (0.1 ppm) on the haematological and biochemical parameters of Clarias batrachus and assessed the protective potential of gallic acid as a natural antioxidant. Fish were divided into five groups: control (G1), malathion-treated (G2), and malathion combined with gallic acid at 50, 100, and 150 mg/L (G3– G5). After 96 hours of exposure, significant haematological alterations were observed in the malathion-treated group, including increased haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC), alongside decreased red blood cell (RBC), total leukocyte count (TLC), and platelet levels. Biochemical analysis revealed reduced albumin, transaminases (SGOT, SGPT, AST), uric acid, and glucose levels, with elevated bilirubin, urea, creatinine, and total lipids, indicating hepatic dysfunction, renal stress, and metabolic imbalance. Gallic acid supplementation significantly ameliorated these alterations in a dose-dependent manner, with the highest recovery observed at 150 mg/L (G5). The findings demonstrate that malathion induces acute systemic toxicity in Clarias batrachus, while gallic acid confers substantial protective effects, likely through its antioxidant properties. This study highlights the potential application of natural antioxidants in mitigating pesticide-induced toxicity in aquaculture and emphasises the ecological risks associated with organophosphate contamination in aquatic environments