Abstract

Oxidative stress is an imbalance between endogenous antioxidants and oxidizing molecules, the latter having an unpaired electron in their last valence layer, with those derived from oxygen and nitrogen being the most important. Resveratrol is a natural polyphenol with antioxidant properties that reduce oxidative stress. However, the bioavailability of resveratrol is low due to its rapid excretion and extensive metabolism. Polyphenols improve their bioavailability in the presence of ethanol, a popular substance present in alcoholic beverages, which is used as a vehicle in the pharmaceutical industry. The objective of this work was to determine the optimal concentration of ethanol for the administration of resveratrol at a concentration of 10 mg/kg/day. Fifty-four Wistar male rats were randomly allocated to nine groups: control (water), four vehicle groups (2.5%, 5%, 7.5%, and 10% ethanol v/v), and four resveratrol + vehicle groups (10 mg/kg/day + ethanol concentrations 2.5%–10%) (ResVitále®, Polygonum cuspidatum, USA). Posterior to administration, the hippocampus of Wistar rats was analyzed for oxidative stress and enzyme activity. Nitric oxide levels and lipid peroxidation products were significantly lower with 7.5% ethanol, compared to 10% ethanol. Resveratrol modulated CAT and SOD activity at certain ethanol concentrations, with a limited overall effect. In conclusion, 7.5% ethanol is the most optimal vehicle concentration for enhancing the antioxidant effects of resveratrol.