The findings from this in Vitro study suggest that theaflavins
inhibit cholesterol incorporation in soluble micelles with a
specific role for theaflavin-3-gallate as the most active theaflavin
on micelle formation. Also, tea extracts from green and black
tea reduced the incorporation of cholesterol into mixed micelles,
which suggests that extracted compounds (e.g., catechins,
theaflavins, flavonols, and thearubigins) from both teas reduce
the incorporation of cholesterol into mixed micelles. The results
also suggest that only the incorporation of cholesterol and not
two other micellar lipids, glycocholic acid and oleic acid, was
affected by theaflavins. Similar in Vitro effects on decreased
cholesterol incorporation in mixed micelles were reported by
Ikeda et al. (10, 17), Raederstorff et al. (11), and others for
green tea catechins, especially epigallocatechin-gallate (EGCg).
In the production of black tea, EGCg is converted by the
polyphenol oxidase (PPO)-induced enzymatic “fermentation”
together with epicatechin into the most active theaflavin-3-
gallate (18). The presence of a gallate moiety in tea polyphenols
seems to play a major inhibitory role in the formation of mixed
micelles.