Functional properties and effective phytochemicals of yam (Dioscorea spp.)

Yams are perennial trailing rhizome plants of the ?Dioscorea? species and a staple food around the world. Yams contain many nutrients and exhibit hypoglycemic, antioxidative, antitumor, antibacterial, antimutagenic, and antineoplastic activities. Saponins (furostanol and spirostanol glycosides), phytosterols (sitosterol, stigmasterol and campesterol), glycans (dioscorans), dioscoretine, diosbulins, (+)-?-eudesmol and paeonol are the active phytochemicals in yams. The aim of this study is to review the biological activities and relevant components of yam.