Antioxidant activities of Moringa oleifera leaf extract against pendimethalin-induced oxidative stress and genotoxicity in Nile tilapia, Oreochromis niloticus (L.)

Abstract

To assess the ameliorative effects of Moringa oleifera (MO) leaf extract on haematological and biochemical changes, liver DNA damage and oxidative stress biomarkers in Nile tilapia (Oreochromis niloticus) exposed to a sublethal concentration (0.52 mg/l) of pendimethalin (PM). Tilapia fish were allocated into four equal groups in tri-replicates as follows: first group was the control group, second group was treated with MO (20 ml/30 l water), third group was exposed to 0.52 mg PM/l and fourth group was exposed to 0.52 mg PM/l and treated with MO leaf extract (20 ml/ 30 l water) for 28 days. At the end of this period, blood and liver tissue samples were collected and haematological and biochemical changes, hepatic DNA fragmentation and oxidative stress biomarkers were analysed. Pendimethalin caused significant reduction in haematological profile [White blood cells (WBCs) and red blood cells (RBCs) counts, haemoglobin (Hb) concentration and haematocrit (Ht) level]; meanwhile, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatinine, uric acid, glucose, cortisol, cholesterol and lactate dehydrogenase (LDH) were significantly increased. On the other hand, serum total protein, albumin, globulin and acetylcholinesterase (AChE) were decreased. Significant reduction in hepatic superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC) and glutathione peroxidase (GSH-Px) levels and marked increments of hepatic malondialdehyde (MDA) and DNA fragmentation were observed in PM-exposed fish compared to the control group. The addition of Moringa oleifera leaf extract into the water could overcome the negative impacts of pendimethalin and normalise the examined parameters nearly to the control values. Moringa oleifera was used for the first time to protect tilapia fish against PM-induced toxicity. The present study revealed that Moringa oleifera has potent antioxidant and antigenotoxic actions against pendimethalin toxicity