Inhibitory effect of green tea on injury to a cultured renal epithelial cell line, LLC-PK1

When cells from a cultured renal epithelial cell line, LLC-PK1, were cultured under hypoxic conditions (oxygen concentration of 2% or less) before reoxygenation was applied (95% air, 5% CO2), the leakage of lactate dehydrogenase (LDH) into the medium increased, This phenomenon was inhibited in the presence of dimethyl sulfoxide, a hydroxyl radical scavenger, suggesting the involvement of free radicals, Such oxidative stress was significantly inhibited by a green tea er;tract, and more potently by a tannin mixture, On the other hand, under ordinary culture conditions (95% air, 5% CO2), there was cell injury, although the LDH leakage was less than that under hypoxia/reoxygenation, and such injury was inhibited by the green tea extract and the tannin mixture.