Effect of Helicteres isora bark extracts on brain antioxidant status and lipid peroxidation in streptozotocin diabetic rats

Abstract

The current study investigated the effect of the aqueous extract of Helicteres isora L (Sterculiaceae) bark on oxidative stress in the brains of rats during diabetes. The aqueous extract of H. isora bark was administered orally (100, 200 mg/kg b.w.) and the effect of the extract on blood glucose, plasma insulin, and the levels of thiobarbituric acid reactive substances (TBARS), hydroperoxides, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and reduced glutathione (GSH) were estimated in streptozotocin (STZ) diabetic rats. Tolbutamide was used as the standard reference drug. A significant increase in the activities of plasma insulin, SOD, CAT, GPx, GST, and GSH were observed in the brain on treatment with 100 and 200 mg/kg b.w. of H. isora bark extract (HIBe) and tolbutamide for 5 weeks. Both treated groups (bark extract and drug) showed a significant decrease in TBARS and hydroperoxides formation in brain, suggesting its role in protection against lipid peroxidation-induced membrane damage. These findings suggest a possible antiperoxidative role of H. isora bark extract that may be used for therapeutic purposes. © 2007 Informa Healthcare USA, Inc.