Anti-Tumor Activity of Oleanolic, Ursolic and Glycyrrhetinic Acid

Over last few years, there has been great interest on the anti-tumor properties of the triterpenoids, oleanolic, ur- solic and glycyrrhetinic acid in presence of many plants such as Olea europeae L., Actostaphylos uva-ursi and Glycyr- rhiza uralensis. The three acids and their derivatives show potential anti-tumor promoting and cytotoxic activities, inhibit- ing proliferation, inducing apotosis and preventing invasion, which suggested that they could be developed as anti-cancer and cancer chemopreventive agents. The mechanisms of the anti-tumor effects by triterpenoids need further investigation. A brief review is attempted here for their anti-tumor activities and chemical modification research.