Modulation of Restraint Induced Gastric Oxidative Changes in Rats by Tocotrienol and Tocopherol

The present study compares the effect of tocotrienol mixture and (alpha)-tocopherol on gastric malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), reduced and oxidized glutathione (GSH and GSSG) content and prostaglandin E2 1evel in rats exposed to restraint stress. Twenty-four male Sprague dawley rats were randomly assigned into 4 equal sized groups; two control groups and two treated groups which were supplemented with either tocotrienol (IT) or (alpha)-tocopherol (TF) orally at a dose of 60 mg kg^-1 body weight. After 28 days of treatment, one control group, the TT and TF groups were subjected to restraint stress, 2 h daily for 4 consecutive days. After the last exposure to stress, the stomach was excised for the evaluation of the parameters. Present findings showed that TT was better in preventing the formation of gastric lesion compared to TF while both TT and TF significantly reduces the gastric MDA content compared to stress control. We also found that both TT and TF have the ability to reduce prostaglandin E2 loss which was apparent with stress exposure. The endogenous content of antioxidant enzyme GPx activity and GSH content was maintained towards the normal levels in rats receiving TT but not in the TF treated group. The SOD level however was not altered in stressed rats. As a conclusion, tocotrienol posses a better protective effect against stress-induced gastric lesions compared to (alpha)-tocopherol. The protective effect was associated with decreased lipid peroxidation, increased prostaglandin E2 (PGE2) and restoration of GPx activity and GSH content which was altered by stress.