Effects of vitamin E on phospholipase A(2) activity and oxidative damage to the liver in streptozotocin-induced diabetic rats

Background: The purpose of the present study was to investigate the effects of vitamin E on oxidative stress and cell membrane fluidity in the liver of streptozotocin (STZ)- induced diabetic rats. Methods: Sprague-Dawley male rats weighing 100 +/- 10 g were fed a vitamin E- free diet (the DM-0E group), a 40 mg vitamin E/kg diet ( the DM-40E group), or a 400 mg vitamin E/ kg diet (the DM-400E group). Result: Dietary vitamin E reduced the increased concentration of lipid peroxides in the liver tissues of diabetic rats through decreasing their increased phospholipase A(2) (PLA(2)) activity and phosphatidylethanolamine hydrolysis. However, vitamin E reduced the accumulation of superoxide radical and decreased the generation of oxidative damage substances, such as the carbonyl value, increased membrane fluidity and lowered oxidative damage. Conclusions: Vitamin E was found to be excellent for regulating the activity of PLA(2), reducing the generation of reactive oxygen species and damaging oxidative substances, and maintaining cell membrane fluidity in the liver of diabetic rats. Copyright (c) 2005 S. Karger AG, Basel.