Oxyradical scavenging effects of dehydroascorbate.

Dehydroascorbate (DHA) has been shown to possess vitamin C like activities as well as to protect the lens against oxidative stress and cataract formation. The results presented here suggest that some of the beneficial effects of DHA can be attributed to its property of undergoing peroxidative decarboxylation and of O2-. scavenging. Incubation of 1-14C-DHA with peroxide at physiological pH has been found to liberate 14CO2 in quantitative yields, with recovery of 79-94%. The recovery increases with the increase in the amount of DHA used. Its O2-. scavenging activity was apparent by inhibition of O2-. dependent reduction of ferricytochrome c and nitroblue tetrazolium. The authenticity of the latter mechanism was proved by inhibition of the O2-. dependent reactions also by superoxide dismutase.