Pharmacokinetics of resveratrol metabolic profile in healthy humans after moderate consumption of red wine and grape extract tablets.

A pharmacokinetic study of the metabolic profile of resveratrol has been performed in healthy men after moderate red wine (RW) consumption. The bioavailability of resveratrol is highly influenced by several factors such as the food matrix and, therefore, this study has been compared with a pilot study in which men ingested grape extract (GE) tablets as a nutraceutical, containing similar total amounts of resveratrol than RW. Blood and urine samples were taken before and at several time points after intervention and then analyzed by SPE and LC-ESI-MS/MS. Up to 17 resveratrol and piceid derivatives were identified, including those formed by the intestinal microbiota. Resveratrol glucosides were found in plasma as intact forms and reached the lowest maximum concentrations 1h after both interventions. Higher plasma concentrations and longer times (t(max)) were observed for resveratrol glucuronides due to phase II metabolism and even higher values for conjugates derived from microbiota, such as dihydroresveratrol-glucuronides. The same trend was observed for total excreted amounts in urine samples. When both treatments were compared, statistically significant differences for some metabolites were obtained, which may be due to the different composition of resveratrol and piceid in both sources. However, GE formulation seems to delay resveratrol absorption, staying longer in the gut where could be metabolized to a greater degree, since 2.1-3.6-fold higher urinary concentrations of microbial metabolites were observed after GE intervention at 12-24h urinary fraction. Therefore, supplement intake could be also a way to bring resveratrol benefits to human health.