Strobilanthes crispus Extract Induces Apoptosis Through Enhanced Caspases Activities in Cervical Cancer Cells

Abstract

Strobilanthes crispus extract was found to exert cytotoxicity on several cancer cell lines and able to reduce chemically-induced hepatocarcinogenesis in rats. In this study, the cytotoxicity of S. crispus extracts that isolated from leaves and stem by hexane, chloroform, ethyl acetate, methanol and water solvent was determined and its possible underlying apoptotic mechanism was further investigated in HeLa cell line. MTT analysis demonstrated that only hexane-stem extract portrayed cytotoxic effects on HeLa cells with IC 50 of 160 μg/ml. Chloform extract showed possible cell inhibition trend while other extracts showed little or no cytotoxic effects. Hexane-stem extract was further analysed in this study where it was found to induce apoptosis, which was confirmed with obvious morphological changes in HeLa cells accompanied by sub-G 1 peak detection in cell cycle analysis by flow cytometry. Hexane-stem extract did not induce cell cycle arrest at any phases based on data shown. High level of caspase-3/7 activity detected indicated the involvement of caspase-3/7 activation in the apoptogenic effect induced by hexane-stem extract. Activity of caspase-8 and caspase-9 were found not significant in this study. More studies could be carried out to further elucidate the apoptotic mechanism clearly. Overall findings showed that S. crispus acted as apoptotic inducer which could be used as potential anticancer agent in the future.