Beneficial effects of curcumin on antitumor activity and adverse reactions of doxorubicin.

Many medicines used in cancer chemotherapy decrease the quality of life (QOL). It is believed that an increase in food intake during cancer chemotherapy may produce an improvement in QOL. Curcumin is widely used as a coloring and flavoring agent in food. The effects of curcumin in relation to the chemotherapeutic drug doxorubicin (DOX) were examined. While DOX alone did not decrease tumor weight, the combination of DOX and curcumin significantly reduced tumor weight to 56.5% (p<0.05) of that of the control group. The combined curcumin enhanced apoptosis by DOX and decreased cell viability. The curcumin-DOX combination also suppressed activation of caspase-3, -8, and -9 compared to DOX alone. It is presumed that combining curcumin increased DOX-induced antitumor activity by suppressing the main caspase pathway and activating the main caspase independent pathway. The combination of curcumin and DOX suppressed the reduction of glutathione peroxidase activity and increased lipid peroxide levels in the heart. Therefore, it is expected that curcumin may reduce the adverse reactions associated with DOX. Our results suggest that curcumin can be used as a modulator to enhance the therapeutic index of cancer patients and improve their QOL.