Antioxidant effect of ethanol extract of powdered grape skin in C57BL/6J mice fed high‐fat diet

Abstract

Grape seeds and skins are good sources of phytochemicals such as gallic acid, catechin, and epicatechin and are suitable raw materials for the production of antioxidative dietary supplements. And grape skins were a much more potent source than either grape pulp, juice or seeds. This study investigated the effect of ethanol extract of powdered grape skin antioxidant metabolism in high fat fed C57BL/6J mice. Five‐week‐old male C57BL/6J mice were randomly divided into two groups and fed high‐fat diet (HF control, 20%fat(w/w)) and with ethanol extract of powdered grape skin(GS) for 9 weeks. The plasma total cholesterol concentration was significantly higher in the HF group. Hepatic glutathione reductase, erythrocyte superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase activities were significantly higher in the GS group than in the HF group. Erythrocyte thiobarbituric reactive substances (TBARS) level was tended to be lower in the GS group than in the HF group. Therefore, we suggest that grape skin is effective material on improvement of antioxidant metabolsim because GS supplementation induced the elevation of hepatic antioxidant enzyme activities, the reduction of erythrocyte lipid peroxide levels and hypocholesterolemic effects in high‐fat‐fed mice.