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.

SummaryGlucosone (D-arabino-hexos-2-ulose), a typical enediol prod uct formed both in the Maillard reaction and Tradiolysis of sugars, decreased survival of Chinese hamster lung V79 cells, which were in cubated under MEM for 4h. Inhibition of the decrease in cell servival by catalase and SOD suggests the role of active oxygen species, namely H2O2 and O2-, in the biological effects of glucosone. H2O2 was formed in the medium during oxidative degradation of glucosone. Inhibition of the formation of H2O2 by SOD indicates that the formation of H2O2 and the consequent decrease of the cell survival was enhanced by O2-. These results suggest that the mechanisms of the effects of glucosone on the mammalian cells in the absence of Cu2+ are different from those in the presence of Cu2+.

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