Possible amelioration of oxidative stress damage via cyclo-oxygenase pathway by aqueous extract of Terminalia catappa leaves in alloxan induced diabetic rats

Cellular damage due to oxidative stress had been implicated in the pathogenesis of many diseases including diabetes mellitus. This study was to investigate possible amelioration of oxidative stress in diabetes mellitus by aqueous leaf extract of Terminalia catappa. Wistar rats weighing 200 -250g was divided into nine groups with 6 rats per group. The main test group has 5 groups while the group for assessing possible mechanism had 4 groups. Group 1 (control) and group 2(non-diabetic) received orally per kg body weight; 0.5ml distilled water and 130mg of Terminalia catappa respectively. Group 3 (diabetic), group 4 (diabetic + extract) and group 5 (diabetic + insulin) also respectively received 0.5ml distilled water, 130mg Terminalia. catappa extract and 0.75UI insulin subcutaneously. Groups 6, 7, 8 and 9 administered orally with aspirin; 30mg/kg, meloxicam; 2mg/kg and combination of extract with aspirin and meloxicam respectively. The experiment lasted for 14 days and glucose level ≥ 200mg/dl was considered diabetic following intraperitoneal injection of 150mg/kg body weight of alloxan. Results showed significant (p<0.05) increase in serum low density lipoprotein cholesterol (LDL-c), malondialdehyde (MDA) and a significant (p<0.05) decrease in superoxide dismutase (SOD) in diabetic group compared with control. The LDL and MDA were significantly (p<0.05) reduced while SOD increased significantly (p<0.05) when compared with diabetic group and the control following administration of Terminalia catappa, aspirin, meloxicam and insulin. The leaf extract of Terminalia catappa possess possible ameliorating potential on oxidative stress induced damages by impeding lipid peroxidation but improved on antioxidant enzyme in diabetic condition.