Dietary curcumin inhibits chemotherapy-induced apoptosis in models of human breast cancer.
Curcumin, the major component of the spice turmeric, is used as a coloring and flavoring additive in many foods and has attracted interest because of its anti-inflammatory and chemopreventive activities. However, this agent also inhibits the generation of reactive oxygen species (ROS) and the c-Jun NH(2)-terminal kinase (JNK) pathway, and because many chemotherapeutic drugs generate ROS and activate JNK in the course of inducing apoptosis, we considered the possibility that curcumin might antagonize their antitumor efficacy. Studies in tissue culture revealed that curcumin inhibited camptothecin-, mechlorethamine-, and doxorubicin-induced apoptosis of MCF-7, MDA-MB-231, and BT-474 human breast cancer cells by up to 70%. Inhibition of programmed cell death was time and concentration dependent, but occurred after relatively brief 3-h exposures, or at curcumin concentrations of 1 microM that have been documented in Phase I chemoprevention trials. Under these conditions, curcumin exhibited antioxidant properties and inhibited both JNK activation and mitochondrial release of cytochrome c in a concentration-dependent manner. Using an in vivo model of human breast cancer, dietary supplementation with curcumin was found to significantly inhibit cyclophosphamide-induced tumor regression. Such dietary supplementation was accompanied by a decrease in the activation of apoptosis by cyclophosphamide, as well as decreased JNK activation. These findings support the hypothesis that dietary curcumin can inhibit chemotherapy-induced apoptosis through inhibition of ROS generation and blockade of JNK function, and suggest that additional studies are needed to determine whether breast cancer patients undergoing chemotherapy should avoid curcumin supplementation, and possibly even limit their exposure to curcumin-containing foods.
Somasundaram
Sivagurunathan
S
The Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7295, USA.
Edmund
Natalie A
NA
Moore
Dominic T
DT
Small
George W
GW
Shi
Yue Y
YY
Orlowski
Robert Z
RZ
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D018906:Antineoplastic Agents, Alkylating / Q000037:antagonists & inhibitors / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002166:Camptothecin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003474:Curcumin / Q000009:adverse effects*; D003520:Cyclophosphamide / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D004032:Diet; D004347:Drug Interactions; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D051379:Mice; D008819:Mice, Nude; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D018906:Antineoplastic Agents, Alkylating; D003574:Cytochrome c Group; D017382:Reactive Oxygen Species; D003520:Cyclophosphamide; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D003474:Curcumin; D002166:Camptothecin