Aim: Previous studies have reported that Phlomis russeliana shows cytotoxic effects against several cancer cell lines; however, its anti cancer activity on HCT-116 cancer cells has not yet been investigated. Therefore, the present study is designed to explore anti-cancer properties of Phlomis russeliana against HCT-116 human colon cancer cell line and HUVEC normal cell line.
 Material and Methods: HCT-116 cells and HUVECs treated with different concentrations of Phlomis russeliana (2, 4, 6, 8 and 10 mg/ml) and cell viability evaluated by the MTT assay. Anti-migratory and anti-colonigenic effects of Phlomis russeliana were assessed with wound healing and colony formation assays respectively. Quantitative determination of total antioxidant status (TAS), total oxidant status (TOS) and caspase-3 activation were performed with colorimetric Elisa kits.
 Results: Phlomis russeliana significantly decreased cell viability of HCT-116 cells in a concentration dependent and showed weaker toxicity against normal HUVECs. Pholomis russeliana significantly inhibited migration and colony formation potential of HCT-116 cells. A significant increase in caspase-3 activation was observed after treatment with Phlomis russeliana. Phlomis russeliana did not significantly affect the TAS and TOS level in HCT-116 cells.
 Conclusion: These results revealed that Phlomis russeliana showed anti-cancer activity in human colon cancer cells, through the suppression of colony formation, inhibition of migration and induction of caspase-3 activation. Phlomis russeliana, could be a promising source for the development of new anti-cancer agents against cancer.