Abstract
Previous studies have shown that the mixture of extracts of grape pomace and omija (GO) improved oxidative stress and obesity in mice. This study first investigated the dose-response effects of GO on oxidative stress and fat-pad mass. Male C57BL/KsJ-db/db mice were fed the following three experimental diets for 7 weeks: a normal control, high-dose grape pomace plus omija (HGO; 0.5% grape pomace plus 0.05% omija fruit, w/w), and low-dose grape pomace plus omija (LGO; 0.3% grape pomace plus 0.05% omija fruit, w/w). The LGO significantly decreased white adipose tissues weights, as well as ameliorated the plasma lipid profiles. The antioxidant effects of LGO led to a significant decrease in the erythrocytic H(2)O(2) and thiobarbituric acid-reactive substance levels, while LGO increased erythrocytic antioxidant activities. These results suggest that LGO is more effective than HGO in lowering oxidative stress and body fat mass in db/db mice.