Trans-resveratrol metabolites

Zamora-Ros et al [2006] carried out the first work that assessed the bioavailability of resveratrol (provided by different wines) in a regular intervention during 28 day. The analyses were performed by LC-MS/MS. In the first study, 10 healthy males were recruited to consume 300 mL/day of sparkling wine (1.19 mg resveratrol/1). After 28 day of supplementation, urinary trans-and m-resveratrol-3-O-glucuronides were 75 and 38 nmol/g creatinine, respectively. In the second study, 10 healthy females were selected to consume 200 mL of white wine (1.99 mg resveratrol/L) or 200 mL of red wine (12.8 mg resveratrol/L) in a crossover clinical trial. Likewise after 28 days only resveratrol metabolites were detected in morning urine, trans- (205 and 473 nmol/g creatinine) and ra-resveratrol-3-O-glucuronidcs (58 and 140 nmol/g creatinine) were found after white and red wine intake, respectively. Those studies showed that urinary excretion was dose dependent. Furthermore, slight amounts of resveratrol metabolites were also detected at baseline periods. No free resveratrol or piceid were detected in any of the studies. 

The effective half-life of resveratrol is reported to be relatively short. Recent work by Soleas et al. [27] indicates that, following oral administration, the concen tration of trans-resveratrol in blood and serum peaked very rapidly in rats. However, its metabolites appear to be more slowly metabolized, and 50-75% of total trarrs-resveratrol seemed to be absorbed in vivo [27]. Another group showed that plasma levels of resveratrol in rabbits, rats, and mice peaked within minutes following intravenous or oral administration (20 mg/kg) [33]. Vascular tissue levels followed plasma levels but were low. Most of the resveratrol measured was found in the trans form and was rapidly metabolized by hepatocytes [33]. In contrast, the pharmacokinetics of the aglycone and glucuronide forms of tra/rs-resveratrol were studied following intravenous or oral administration to rats. As was observed by others, plasma concentrations of resveratrol peaked and then declined rapidly however, a second increase in plasma concentration... 

Quantification of free and protein-bound polyphenol trans-resveratrol (t-RES) metabolites and identification of traws-resveratrol-C/O-conjugated dighicuronides, two novel resveratrol metabolites in human plasma (Figure 9.3), were reported [34]. 

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