Structure-dependent membrane interaction and bioactivity of flavonoids with lipid bilayers

Flavonoids are naturally-occuring compounds, commonly found in teas, wine, and grapes. They have been reported to be biologically active through their interactions with cell membranes. They are widely known to be beneficial to the body due to their anti-oxidant, anti-proliferation and anti-inflammatory effects. Although changes in fluidity of the lipid bilayer had been reported to change in the presence of the flavonoids and association of the flavonoids with the bilayer has been reported, the detailed mechanism of interaction of flavonoids with lipid membranes is not yet well elucidated. Here, we report on the interactions between three flavonoids belonging to flavan-3-ol and thearubigins and stilbenes: a tea catechin (-)-epigallocatechin gallate (EGCg) and its oxidative derivative theaflavin which is found in black tea and piceid which is a resveratrol derivative found in grape juice. Our results show vesicular transformation in the presence of the flavonoids, and there were clear differences between the three flavonoids. We are yet to confirm or refute the presence of flavonoids in those aggregates. As far as we are aware, this is the first time such an experiment has been done.