Comparison of the cytotoxicity of different hydroperoxides to V79 cells.

We compared the cytotoxicity of hydrogen peroxide (H2O2), tertiary butyl hydroperoxide (t-BHP) and methyl linoleate hydroperoxide (MLHP) to V79 cells, using a colony formation assay. In all cases L-buthionine-(S,R)-sulphoximine enhanced the cytotoxicity, and Quin 2 inhibited it. Nordihydroguaiaretic acid (NDGA) and o-phenanthroline suppressed the cytotoxicity of H2O2 and t-BHP, but they had no effect on the cytotoxicity of MLHP. These results suggest that the biological effects of t-BHP are similar to those of H2O2 and not to those of lipid hydroperoxides. In the course of the experiments, we found that NDGA, an antioxidant and food additive, was a potent inhibitor of cytotoxicity of H2O2.