Effects of the oil palm (Elaeis guineensis Jacq.) on lipid oxidation in streptozotocin-induced diabetic rats

Abstract

Antioxidant properties of the phytonutrient-rich oil palm (Elaies guineensis Jacq.) were evaluated in normal and streptozotocin (STZ)-induced diabetic rats. Thirty adult male Sprague-Daley rats were divided into 4 groups: 1) untreated-control rats, 2) only palm oil (PO) (10 ml/kg body wt., orally, for 3 weeks) treated rats, 3) STZ-induced diabetic rats (65 mg/kg intraperitoneally); 4) STZ-induced diabetic rats supplemented with PO (10 ml/kg body wt.,orally) for 3 weeks prior to the STZ-induction. After one week, body weights of the STZ-induced diabetic rats decreased compared to control, whereas thiobarbituric acid reactants (TBARS) levels - an indirect measurement of lipid peroxidation product - were significantly (p=0.001) increased by diabetes but remained unaffected by PO supplement to diabetic rats. No increase in ferric reducing ability of plasma (FRAP) was observed in palm oil treated diabetic rats compared to diabetic control rats. On the contrary, the FRAP level of PO-treated rats was about 20- fold higher (p < 0.05) compared to that of untreated-control group, whilst, a slightly increase in the TBARS level of about 17% was detected in the PO-treated rats. In conclusion, the supplementation of palm oil as an antioxidant to a certain extent reduced lipid oxidation in healthy rats, but worsened or not significantly inhibited in diabetic rats.