Inhibitory effects of crude drug components on the proliferation of cultured human mesangial cells.

The effects of a component of an Oriental medicine and green tea plants utilized for the traditional beverage on the proliferation of mesangial cells were determined in terms of the 3H-thymidine uptake. When magnesium lithospermate B was added to the medium of the mesangial cell culture, it suppressed the proliferation of mesangial cells at a concentration of 50 micrograms/ml. The 3H-thymidine uptake began to display an inhibitory action from the 6.25 micrograms/ml (-)-epicatechin 3-O-gallate, (-)-epigallocatechin 3-O-gallate or green tea tannin mixture, showing a more conspicuous inhibition at 50 micrograms/ml that did the magnesium lithospermate B at the corresponding concentration. In particular, (-)-epigallocatechin 3-O-gallate, the predominant component of the green tea tannin mixture, exerted an inhibitory effect at a relatively low concentration.