Resveratrol Shows Vasoprotective Effect Reducing O

Authors: Fatma Akar M Bilgehan Pektas Can Tufan Selen Soylemez Aylin Sepici A Tulga Ulus Burcu Gokalp Kamile Ozturk H Selcuk Surucu

Publish Date: 2011/01/12

Volume: 25, Issue: 2, Pages: 119-131

PDF Link

Abstract

Resveratrol has been shown to have vasoprotective effects by upregulating oxidative defense mechanisms in a variety of pathophysiological conditions However the effect of resveratrol on diabetic oxidative stress and vascular and metabolic abnormalities is not completely understood Therefore this study was designed to evaluate whether longterm resveratrol supplementation has a protective effect on vascular function and integrity in association with metabolic parameters and oxidative stress in insulindependent diabetesDiabetes was induced in rabbits with alloxan and maintained for 8 weeks We used a resveratrol dose of 5 mg/L 10 weeks starting 14 days before alloxan injection and 50 mg/L 8 or 10 weeks starting concomitantly or 14 days before alloxan injection in the drinking water of rabbitsRelaxation to acetylcholine was impaired control 756 ± 359 versus diabetic 4223 ± 253 and contractions to phenylephrine increased control 13689 ± 227 versus diabetic 15937 ± 627 in aortas from diabetic animals These changes were associated with increased basal or NADPHinduced superoxide production as well as lipid peroxide and superoxide dismutase SOD levels in the aortic samples The maximal relaxation to acetylcholine improved by 7574 ± 904 in diabetic rabbits treated with resveratrol The increased contractions to phenylephrine were not restored to control values after resveratrol treatments but sensitivity to the contractions tended to decrease Resveratrol increased nitrite/nitrate levels and suppressed basal or NADPHinduced superoxide production and lipid peroxide levels in the aortas Importantly resveratrol increased serum insulin levels without affecting blood glucose and the lipid profile in diabetic rabbits Using electron microscopic examinations resveratrol was found to markedly protect the endothelial integrity from diabetesOverall there was no noticeable difference between resveratrol treatment groups on the recovery from diabetes Our results indicate that resveratrol alleviates type 1 diabetesinduced vasculopathy by decreasing vascular oxidative stress and thereby increasing the bioavailability of nitric oxide without changing metabolic abnormalities

Keywords: