Investigation of the absorption of resveratrol oligomers in the Caco-2 cellular model of intestinal absorption

Resveratrol oligomers are biologically active polyphenols found in wine. No information about the bio-availability of these polyphenols is available. In order to discover if the resveratrol oligomers can pass the intestinal barrier, transport of the dimer epsilon-viniferin and the tetramer hopeaphenol was studied in the Caco-2 transwell system. A flux through the cell monolayer could neither be observed for epsilon-viniferin nor for hopeaphenol (apparent permeability coefficient (P-app) < 1 x 10(-6) cm s(-1)). In contrast, resveratrol showed a P-app of 11.9 x 10(-6) cm s(-1). Nevertheless, about 16-30% of the oligomers were found in the lysed cellular fraction. This leads to the conclusion that the intestinal absorption rate of the two resveratrol oligomers, epsilon-viniferin and hopeaphenol, is low and negligible when compared to resveratrol. Therefore, it is unlikely that the oligomers could elicit a systemic biological effect after dietary intake. However, the compounds may act locally on the intestinal epithelium. (C) 2014 Elsevier Ltd. All rights reserved.