Influence of anthocyanins and derivative pigments from blueberry (Vaccinium myrtillus) extracts on MPP+ intestinal uptake:: A structure-activity approach

The aim of the present study was to investigate the influence of an anthocyanin extract (extract I), and two other derivative extracts (extracts II and II), which are being developed aiming to be further applied in the food industry, on intestinal uptake of organic cations. For this purpose, the effect of these compounds on H-3-MPP+ uptake was evaluated in Caco-2 cells (an enterocyte-like cell line derived from a human colonic adenocarcinoma). Extracts I and III did not present any effect on H-3-MPP+ uptake. Extract II, an anthocyanin-pyruvic acid adduct extract, decreased organic cation uptake. Some phenolic molecules were also tested, aiming to study possible structural features responsible for these effects. The results are compatible with the hypothesis of phenolic molecules bearing a carboxylic group with extended electronic conjugation being the responsible feature for the inhibitory effect on H-3-MPP+ uptake. The use of these compounds in foodstuffs must be carefully assessed since interactions with organic cations present in the diet, as nutrients or xenobiotics, may affect their absorption and bioavailability. Type and complexity of the ingested compounds are important factors in this regard, and should be taken into consideration. (C) 2008 Elsevier Ltd. All rights reserved.