Anthracyclinones cardiotoxicity

Avery important mechanism of use-limiting anthracycline cardiotoxicity involves the formation of cytotoxic free radicals. A free radical is a highly reactive species with an unpaired electron. Of particular importance to the antineoplastic action of these drugs is the formation of the superoxide radical anion ( O2 ) and the hydroxyl radical ( OH), both of which are formed via reduction of the anthracyclinone quinone (ring C) to hydroquinone by NADPH/CYP450 reductase. The mechanism by which cytotoxic free radicals are generated is shown in Figure 42.18. 

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