Flavonoid-procyanidin interaction

Interaction of Flavonoids and Procyanidins at Membrane Water-Lipid Interfaces... 

The finding that water-soluble flavonoids could exert their beneficial properties at the hydrophobic portion of the membrane was also observed in in vivo studies and in cells in culture. For example, erythrocytes obtained from animals fed a flavanol- and procyanidin-rich meal showed reduced susceptibility to free-radical-mediated hemolysis [Zhu et al., 2002]. Consistently, we demonstrated that procyanidin hexamers, which interact with membranes but would not be internalized, protected Caco-2 cells from AMVN- and bile-induced oxidation [Erlejman et al., 2006]. When liposomes were preincubated with a series of flavonoids with diverse hydrophobicity, not only hydrophobic flavonoids prevented AMVN-mediated lipid oxidation but also the more hydrophilic ones [Erlejman et al., 2004]. Similarly to what was previously found in liposomes, the protective effects of flavonoids against AMVN-supported oxidation was strongly associated with their capacity to prevent membrane disruption by detergents, supporting the hypothesis of a physical protection of membranes by preventing oxidants to reach fatty acids. 

Procyanidins have been considered antinutritional compounds because they can interact with proteins, starch, essential amino acids, and carbohydrates and inhibit certain enzymes [121-123]. This binding depends on the degree of polymerization the larger molecules tend to bind more efficiently [7]. However, at the dose present in cocoa no adverse effect has been observed [124, 125]. In addition, the level of flavonoids required to induce mutations and cytotoxicity may not be physiologically achievable through dietary sources however the use of flavonoid supplements could result in... 

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