On the bioavailability of flavanols and anthocyanins: Flavanol–anthocyanin dimers

The bioavailability of flavanols, anthocyanins and anthocyanin-derived pigments like flavanol–anthocyanin dimers already reported to occur in food products is a major unsolved issue. The absorption of the flavanol–anthocyanin dimer (+)-catechin-(4,8)-malvidin-3-O-glucoside (Cat–Mv3glc) through Caco-2 cells was assessed by performing transepithelial transport assays. The ability of Cat–Mv3glc to cross Caco-2 cells was compared with that of malvidin-3-glucoside (Mv3glc), (+)-catechin (Cat) and procyanidin B3 (Cat–Cat), in order to evaluate the influence of some structural features on the transport efficiency. The flavanol–anthocyanin dimer was absorbed in this intestinal model although with a lower efficiency than the monomers Cat and Mv3glc. On the other hand, Cat–Mv3glc was found to cross the intestinal barrier model more significantly than Cat–Cat. This feature may be related to the presence of the glucose moiety in its structure. Overall, this study brings more insights into the bioavailability of anthocyanins and flavanols and represents the first report on the bioavailability of flavanol–anthocyanins.