PT - JOURNAL ARTICLE AU - Thomas Walle AU - Faye Hsieh AU - Mark H. DeLegge AU - John E. Oatis, Jr. AU - U. Kristina Walle TI - HIGH ABSORPTION BUT VERY LOW BIOAVAILABILITY OF ORAL RESVERATROL IN HUMANS AID - 10.1124/dmd.104.000885 DP - 2004 Dec 01 TA - Drug Metabolism and Disposition PG - 1377--1382 VI - 32 IP - 12 4099 - http://dmd.aspetjournals.org/content/32/12/1377.short 4100 - http://dmd.aspetjournals.org/content/32/12/1377.full SO - Drug Metab Dispos2004 Dec 01; 32 AB - The dietary polyphenol resveratrol has been shown to have chemopreventive activity against cardiovascular disease and a variety of cancers in model systems, but it is not clear whether the drug reaches the proposed sites of action in vivo after oral ingestion, especially in humans. In this study, we examined the absorption, bioavailability, and metabolism of 14C-resveratrol after oral and i.v. doses in six human volunteers. The absorption of a dietary relevant 25-mg oral dose was at least 70%, with peak plasma levels of resveratrol and metabolites of 491 ± 90 ng/ml (about 2 μM) and a plasma half-life of 9.2 ± 0.6 h. However, only trace amounts of unchanged resveratrol (<5 ng/ml) could be detected in plasma. Most of the oral dose was recovered in urine, and liquid chromatography/mass spectrometry analysis identified three metabolic pathways, i.e., sulfate and glucuronic acid conjugation of the phenolic groups and, interestingly, hydrogenation of the aliphatic double bond, the latter likely produced by the intestinal microflora. Extremely rapid sulfate conjugation by the intestine/liver appears to be the rate-limiting step in resveratrol's bioavailability. Although the systemic bioavailability of resveratrol is very low, accumulation of resveratrol in epithelial cells along the aerodigestive tract and potentially active resveratrol metabolites may still produce cancer-preventive and other effects. The American Society for Pharmacology and Experimental Therapeutics