Terpenoids from Curcumae Rhizoma: Their anticancer effects and clinical uses on combination and versus drug therapies

Cancer is a fatal disease with high mortality and low survival rate worldwide. At present, there is still no known cure for most cancers. Traditional Chinese medicine (TCM) represents a noteworthy reservoir for anticancer agents in drug discovery and development. Curcumae Rhizoma (called Ezhu in Chinese) is widely prescribed in TCM for anticancer therapy owing to its broad-spectrum antineoplastic activities. Especially, the terpenoids isolated from the essential oil of Curcumae Rhizoma form an integral part of cancer research and are well established as a potential anticancer agent. For example, β-elemene has been developed into a new drug for the treatment of solid tumors in China, and is currently undergoing clinical trials in the United States. The review aims to systematically summarize the recent advances on the anticancer effects and related molecular mechanisms of Curcumae Rhizoma, and its terpenoids (β-elemene, Furanodiene, Furanodienone, Germacrone, Curcumol, Curdione). In addition, we evaluated and compared the anticancer efficacy and clinical use of the terpenoids with combination therapies and traditional therapies. Therefore, this review provides sufficient evidence for the anticancer therapeutic potential of Curcumae Rhizoma and its terpenoids, and will contribute to the development of potential anticancer drugs.