Cytotoxic and Antitumor Activity of the Extract of Clerodendron infortunatum: A Mechanistic Study

Objective: To investigate the molecular mechanism of anti tumor activity of Clerodendron infortunatum extract (CIE) under in vitro condition. Materials and Methods: The cytotoxic activity of CIE extract was tested on murine tumor cells (Dalton’s lymphoma ascites cells - DLA) and normal mouse cells (splenocytes) by trypan blue dye exclusion assay. The ability of the extract to induce apoptosis was measured via acridine orange and propidium iodide dual staining method. Apoptosis induction was confirmed by the analysis of level of expression of various apoptotic genes like bax, bcl-2, caspase 8 and caspase 9. Results: The extract showed a dose dependent anti-proliferative activity on DLA cells whereas mouse splenocytes were found to be not affected. Treatment of DLA cells with CIE increased the number of apoptotic events in DLA cells. Increase in the bax/bcl-2 ratio along with an escalation in the expression of caspase 9 by almost 60 fold confirmed the induction of intrinsic pathway of apoptosis. Conclusions: CIE showed effective anti-proliferative activity on DLA cells by the induction of intrinsic pathway of apoptosis