Role of curcumin in cancer therapy.

A lthough our knowledge of cancer biology has advanced a great deal, neither the incidence of cancer nor the rate of death due to cancer has changed in the last 50 years. Most drugs currently available for the treatment of cancer have limited potential because they are very toxic, highly inefficient in treating cancer, or highly expensive and thus beyond the reach of the majority. Treatments without these disadvantages are needed. Curcumin is one such agent; derived from turmeric (Curcumin longa), it has been used for thousands of years in the Orient as a healing agent for variety of illnesses. Research over the last few decades has shown that curcumin is a potent antiinflammatory agent with strong therapeutic potential against a variety of cancers. Curcumin has been shown to suppress transformation, proliferation, and metastasis of tumors. These effects are mediated through its regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. It also inhibits proliferation of cancer cells by arresting them in various phases of the cell cycle and by inducing apoptosis. Moreover, curcumin has the ability to inhibit carcinogen bioactivation via suppression of specific cytochrome P450 isozymes, and to induce the activity or expression of phase II carcinogen detoxifying enzymes, which may account for its cancer chemopreventive effects. Curcumin has been shown to have protective and therapeutic effects against cancers of the blood, skin, oral cavity, lung, pancreas, and intestinal tract, and to suppress angiogenesis and metastasis in rodents. The current review focuses on the molecular mechanisms by which curcumin mediates its effects against various cancers. Curcumin is the most active component of turmeric, a botanical agent derived from the dried rhizome of the turmeric plant (Curcuma longa), a perennial herb belonging to the ginger family that is cultivated extensively in south and southeast tropical Asia. The rhizome, or root, is processed into turmeric powder, which is 2% to 5% curcumin. Turmeric is widely consumed in 1 the Indian subcontinent, south Asia, and Japan. It has a variety of uses;