Transport behavior of ellagic acid of pomegranate leaf tannins and its correlation with total cholesterol alteration in HepG2 cells

The aim of this study was to investigate whether ellagic acid in pomegranate leaf tannins could be transported into HepG2 cells and its transport behavior. High-performance liquid chromatography coupled with a 996 photodiode array detector at 254 nm was applied. The mobile phase was an acetonitrile–water solution (containing 0.1% triethylamine, pH 3.0; 16:64, v/v, for determining ellagic acid in cells). The flow rate was 0.8 mL/min. Cells were incubated with pomegranate leaf tannins with 100 and 50 µg/mL (containing 1.71 and 0.85 µg/mL of ellagic acid, respectively) for a specific time, then lysed and sonicated in methanol to extract intracellular ellagic acid. A 10 µL aliquot of sample was injected into the HPLC system to determine ellagic acid concentration. The results showed that ellagic acid in pomegranate leaf tannins could be transported into the cells, which was in correlation with total cholesterol alteration in the cells. This is the first time that the transport behavior of ellagic acid through HepG2 cells in vitro has been comprehensively demonstrated. Copyright © 2008 John Wiley & Sons, Ltd.