Nitroxide radicals inhibit lipid peroxidation in the heart tissue in doxorubicin treated rats

The antioxidative effect of structurally related piperidine nitroxides Tempo and Tempol on oxidative damage induced by doxorubicin (DOX) in vivo in rat heart was examined. A twofold increase in MDA content as compared to control was observed in rats injected with DOX. Tempo was found to be toxic for the heart myocytes and to increase the MDA level while Tempol did not influence lipid peroxidation. Both nitroxides in combination with DOX showed effective antioxidant and cardioprotective effect on heart myocytes and significantly reduced level of lipid peroxidation induced by DOX. Tempo was more cardioprotective against DOX than Tempol. In animals injected simultaneously with Tempo and DOX almost complete inhibition of lipid peroxidation was observed (MDA level was similar to the level of this product in control animals).