Antioxidant effect of grapevine leaf extract on the oxidative stress induced by a high-fat diet in rats

This study was conducted to investigate the effect of grapevine leaf extract (GLE) on the oxidative stress of rats fed a high-fat diet. Rats were divided into six groups: a normal diet with 0% (NC), 1.0% (NG1.0), and 1.5% GLE (NG1.5); and a high-fat diet with 0% (HFC), 1.0% (HFG1.0), and 1.5% GLE (HFG1.5). Treatment with GLE to the high-fat diet reduced lipid peroxide concentrations in plasma and liver compared to those of HFC rats. Total glutathione and GSH/GSSG of the groups with GLE were higher than those of untreated groups. Hepatic glutathione peroxidase, glutathione- S -transferase, and glutathione reductase activities along with catalase and glutathione peroxidase activities in erythrocytes increased after GLE treatment to high-fat diet compared with HFC rats. Hepatic retinol and tocopherol increased in HFG1.5 group compared to those of HFC group. These results indicate that GLE can protect against oxidative stress induced by a high-fat diet in rats.