Curcumin as a cancer chemotherapy sensitizing agent

The development of cancer chemotherapy made a significant progress in cancer treatment. However, most chemotherapeutic drugs are challenged by drug resistance and druginduced toxicity. Combination therapy has been suggested as an effective strategy to avoid drug resistance and reduce toxicity derived from drug, thereby enhancing clinical treatment of cancer. Many food-derived bioactive compounds have exhibited anticancer activity and can be good candidates for combination therapy with existing chemotherapeutic drugs. Curcumin is one of compounds that present anticancer activity in many types of cancer and has been extensively studied for its anticancer mechanisms including inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. Combinational treatment of curcumin enhanced therapeutic efficacy of traditional chemotherapeutic drugs, cisplatin, doxorubicin, 5-fluorouracil, and gemcitabine. NF-κB is a major downstream effector that leads to chemoresistance of many therapeutic drugs. Down-regulation of NF-κB by curcumin is an effective mechanism to sensitize chemotherapeutic drugs and increase therapeutic efficacy. Therefore, combination use of curcumin and available anticancer drugs has great potential to enhance chemotherapy efficacy and improve clinical treatment of cancer. More studies will be required to elucidate cause effect relationship of curcumin-induced suppression of cell survival pathways and enhancement of drug efficacy by curcumin.