Effects of thiol compounds versus the cytotoxicity of valepotriates on cultured hepatoma cells.

The antagonistic activity of various thiol compounds versus the cytotoxic effects of valtrate and didrovaltrate has been evaluated on cultured hepatoma cells. Compounds with free SH groups like cysteine, mercaptoethanol, dithioerythritol, and glutathione were able to suppress the cytotoxicity of the valepotriates in a dose-dependent way, whereas compounds with blocked SH groups did not antagonize these toxic effects. The possible interactions between the valepotriates and thiol compounds are discussed.