Salvurmin A and Salvurmin B, Two Ursane Triterpenoids of Salvia urmiensis Induce Apoptosis and Cell Cycle Arrest in Human Lung Carcinoma Cells

Background: Ursane triterpenoids could be considered as novel multi-target therapeutic anti-cancer agents. Salvurmin A and Salvurmin B are novel cytotoxic ursane triterpenoids isolated from the aerial parts of Salvia urmiensis, an endemic plant species of Iran. Methods: In this study, we assessed cytotoxicity of these compounds against two human cancer cell lines and one human normal cell line and investigated its mechanism via apoptosis and cell cycle arrest. Results: Salvurmin A and B showed the most cytotoxic effect on A549 cells compared to other studied cancer cells. IC50 values for Salvurmin A and B against A549 cells were 35.6 ± 1.5 and 19.2 ± 0.8 µM, respectively. Based on annexin V staining, both of these compounds significantly induced apoptosis in A549 cells. Moreover, these two compounds significantly increased cell accumulation in G2/M and decreased the number of cells in G0/G1 phases in A549 cells in a dose-dependent manner. Conclusion: Based on the results Salvurmin B can be considered as potential candidate for further studies against human lung carcinoma.