Resveratrol and piceid in grapes, peanuts and processed products

H. Schmandke, Bergholz-Rebrücke

Trans-resveratrol is synthesized as stress metabolite (phytoalexin) in medicinal plants (e.g. knotgrass, lilly, cassia) and vegetable food (e.g. grapes and peanuts). Grapes also contain the corresponding 3-O-ß-D-glucoside (piceid or polydatin) which is produced in the skins.

The concentrations of resveratrol and piceid in grape juice and wine depend on the extraction time of the skins. Red wine, because of longer extraction times during fermentation, contain higher concentrations then grape juice and white wine. Moreover, during fermentation the cis-isomers of both compounds are formed. In peanuts, the highest levels of trans-resveratrol are found in the hulls. Roasting reduces the trans-resveratrol content. In peanut butter trans-resveratrol accumulates.

After intake, trans- and cis-resveratrol are quickly absorbed by glucuronidation at the 4‘-hydroxyl group, stored mainly in liver and kidney and excreted with the urine. Resveratrol and, though to less extent, also piceid show antioxidant activity in vitro. Cis-isomers are less active. The same applies to estrogen action.

Resveratrol and piceid reduce the cholesterol level and inhibit LDL peroxidation and platelet aggregation. They reduce the arachidonic acid metabolism by inhibition of lipoxygenase and cyclooxygenase and lower NO-production, by inhibition of nitric oxide synthase, and cytochrome P450 activity.

Resveratrol and piceid, therefore, are assumed to have a preventive and therapeutic potential in cardiovascular diseases and cancer. These assumptions have not been confirmed in humans, however. EU09/02

Keywords: Resveratrol / piceid / grapes / peanuts

Sie finden den Artikel in deutscher Sprache in Ernährungs-Umschau 09/02 ab Seite 349.