INHIBITORY EFFECT OF (-)-EPICATECHIN 4-BENZYLTHIOETHER ON THE GROWTH OF GLIOMA-CELLS IN CULTURE

The effect of (-)-epicatechin 4-benzylthioether (EC-BE) on the growth of cultured rat glioma cells was investigated, EC-BE was found to prod uce a concentration-dependent inhibitory effect on the growth of gliom a cells, Inhibition was also observed in samples treated with (-)-epic atechin acetoxymethyl ester (EC-AM), The original compound(-)-epicatec hin, which gave rise to EC-AM and EC-BE, failed to produce a similar r esult, Because both EC-BE and EC-AM are membrane permeable, while (-)- epicatechin is not, the results indicated that the (-)-epicatechin and its derivatives need to be intracellular in order to produce an effec t, Moreover, it is demonstrated that EC-BE inhibited the incorporation of [H-3]thymidine into DNA while the uptake of extracellular [H-3]thy midine by glioma cells was not affected, The activities of redox enzym es such as glutathione peroxidase and glutathione reductase were atten uated in cells treated with EC-BE, These data suggest that EC-BE can i nhibit the growth of glioma cells by affecting a redox pathway related to the formation of DNA.