... largely in the skins of red grapes and root of Polygonum cuspidatum Sieb. an oriental medicine used to treat diseases of ... natural sources are Vitis vinifera, labrusca, and muscadine grapes, Polygonum cuspidatum Sieb.Cardiovascular Effects Many studies suggest that consuming alcohol.may ... than other well-known antioxidants, such as vitamins C and E. On the other hand, it is less effective than ...