Pancreatic tissue protective nature of D-Pinitol studied in streptozotocin-mediated oxidative stress in experimental diabetic rats

The present study was aimed to investigate the possible pancreatic tissue protective nature of D-Pinitol, a cyclitol present in soybean, against free radical-mediated oxidative stress in streptozotocin-induced diabetic rats by assaying the activity of pancreatic enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione-S-transferase (GST) and the levels of plasma nonenzymatic antioxidants such as vitamin E, vitamin C, ceruloplasmin and reduced glutathione (GSH). To assess the extent of oxidative stress, the levels of lipid peroxidation (LPO) and hydroperoxides in both plasma and pancreatic tissues were also measured. A significant increase in the levels of both lipid peroxides and hydroperoxides with a concomitant decrease in antioxidant status was observed in the diabetic rats when compared to control rats. Oral administration of D-Pinitol (50 mg/kg b.w./day for 30 days), a major cyclitol present in soybean, ameliorates the free radical-mediated alterations to near normalcy. The pancreatic tissue protective nature of D-Pinitol was further evidenced by histological observations. The results were statistically comparable with glyclazide, a standard hypoglycemic drug. Thus, the results of the present study suggest that D-Pinitol protects the pancreatic tissue from free radical-mediated oxidative stress in addition to its antidiabetic property. (C) 2009 Elsevier B.V. All rights reserved.