The Generation of Hydrogen Peroxide, Superoxide Radical, and Hydroxyl Radical by 6-Hydroxydopamine, Dialuric Acid, and Related Cytotoxic Agents

Hydrogen peroxide, superoxide radical, and hydroxyl radical were all formed during the autoxidation of four cytotoxic agents, namely, 6-hydroxydopamine, 6-aminodopamine, 6,7-dihydroxytryptamine, and dialuric acid. Ascorbic acid and 5-hydroxydopamine, two autoxidizable agents of biological interest but without similar cytotoxic actions, were used as negative controls. The results tend to implicate O2-and ·OH, as well as H2O2, in the molecular mechanisms for cytotoxicity.