Ameliorative effects of dietary caloric restriction on oxidative stress and inflammation in the brain of streptozotocin-induced diabetic rats

Background: There is a strong association between oxidative stress and inflammation in the pathologies of diabetes. Recent evidence suggests that these phenomena could impair brain function. We investigated the potential role of dietary caloric restriction in ameliorating the effects of both oxidative stress and inflammation in the brain of streptozotocin-induced type 2 diabetic rats. Methods: Forty male Wistar rats were subjected to 30% caloric restriction (20 animals) and ad libitum feeding (20 animals) for 9 weeks before the induction of diabetes in 20 animals (10 from each group) by intraperitoneal injection of 35 mg/kg body weight streptozotocin. Results: Caloric restriction was able to significantly (p > 0.05) reduce triglyceride, ROS, IL6, TNF-alpha and body weights in diabetic rats. However, no significant differences were obtained in the antioxidant enzyme (SOD, CAT and GPx) activities except in GPx where caloric restriction increased the levels in both non-diabetic and diabetic rats. Conclusion: Caloric restriction was found to ameliorate the oxidative and inflammatory effects of diabetes in the brain. Non-diabetic rats feeding ad libitum were found to have increased levels of oxidative stress and inflammatory biomarkers and these could, in part, be due to their increased body weights. (c) 2006 Elsevier B.V. All rights reserved.