American Journal of Phytomedicine and Clinical Therapeutics www.ajpct.org Original Article Cytotoxic and Antitumor Activity of the Extract of Clerodendron infortunatum: A Mechanistic Study Tiju Chacko 1 , Aditya Menon 1 , Shivaprabha V Nair 1 , Entissar Sulaiman AlSuhailbani 2 and Cherupally Krishnan Krishnan Nair* 1 1 Pushpagiri Institute of Medical Sciences and Research Centre, Thiruvalla - 689101, Kerala, India 2 King Saud University, College of Science, Saudi Arabia ABSTRACT 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. Keywords: Clerodendron infortunatum, Dalton’s lymphoma ascites cells, Apoptosis, bax/bcl-2 ratio. INTRODUCTION Cancer is the second largest common disease and a major Global health burden 1,2 . It was estimated that, worldwide there were 10.9 million new cancer cases, 6.7 million deaths due to cancer, and 24.6 million persons living with cancer in 2012 3-5 . Development of cancer is a multistage process due to the accumulation of mutagenic alterations occurring over a span of years resulting in uncontrolled cell growth and division. These genetic Address for Correspondence Pushpagiri Institute of Medical Sciences and Research Centre, Thiruvalla - 689101, Kerala, India. E-mail: ckknair@yahoo.com