Research in Pharmaceutical Sciences, June 2019; 14(3): 273-285 School of Pharmacy & Pharmaceutical Sciences Received: November 2018 Isfahan University of Medical Sciences Accepted: April 2019 Original Article *Corresponding authors: G. Chaudhry, Tel: +609-6683810, Fax: +609-6684944 Email: sababiochem@gmail.com TST. Muhammad, Tel: +609-6685184, Fax: +609-6684944 Email: sifzizul@umt.edu.my Vitex rotundifolia fractions induce apoptosis in human breast cancer cell line, MCF-7, via extrinsic and intrinsic pathways Gul-e-Saba Chaudhry*, Rehmat Jan, Habsah Mohamad, and Tengku Sifzizul Tengku Muhammad* Institute of Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia. Abstract Breast cancer is amongst frequently diagnosed cancer type throughout the world. Due to reduced efficacy of current chemotherapeutics, several natural products have been screened for better alternatives. The cytotoxic activity of fractions prepared from leaves extract of Vitex rotundifolia (V. rotundifolia) on human breast cancer cell line, MCF-7 was studied. The fractions F1, F2, F3, and F5 of V. rotundifolia produced concentration-dependent cytotoxic effects on MCF-7 cell line. The relative potential of cytotoxicity of the fractions on MCF-7 cell line was found to be F3 > F2 > F5 > F1. The active fractions induce apoptosis in MCF-7 cell line determined by annexin V base assay. The phosphatidylserine externalization and the presence of DNA fragmentation in treated cells confirms the early and late apoptosis in treated cells. The V. rotundifolia fractions induced apoptosis by both pathways; extrinsic pathways via activation of caspase-8 and intrinsic pathways through enhanced bax/bcl-2 ratio and activation of caspase-3/7 and caspase-9 proapoptotic proteins. Furthermore, chemical profiling indicates various phenolic, flavonoids, and terpenoids compounds in the active fractions. Thus, V. rotundifolia might be a suitable candidate to investigate further and develop molecular targeted cancer therapeutics by understanding the fundamental mechanisms involved in the regulation of cell death in cancer cells. Keywords: Apoptosis; Breast cancer; Caspases; DNA fragmentation, Vitex rotundifolia. INTRODUCTION Cancer is the second leading cause of mortality after heart disease. It accounts for more than 6 million deaths each year worldwide (1-2). Lung cancer, breast cancer, prostate cancer, and colorectal cancer are primary diagnosed cancers. Breast cancer is the most commonly diagnosed cancer type in women. It accounts for 23% of all newly occurring cancer cases and 13.7% of all cancer deaths in men and women (2-3). The estimated numbers of 1,762,450 cancer cases diagnosed in the United States in 2019, which is the equivalent of more than 4,800 new cases each day. Also, there will be approximately 62,930 new cases of female breast carcinoma in situ (4). However, it remains the most frequently diagnosed cancer and a prevalent cause of death in women (5). Although extensive preclinical and clinical studies have been carried out in finding anticancer drugs, the majority of potent agents are still not useable due to the harmful effects these candidates may possess. Currently, the development of plant-derived anticancer drugs has gained much interest since naturally-derived compounds are considered to have less toxic side effects compared to synthetic-based drug treatment (6). Plants are rich sources of biologically active and chemically diverse compounds. The secondary metabolites have found considerable use in the treatment of numerous diseases and have been considered lead molecules itself and also as templates for medicinal chemistry (7-8). Over 3000 plant species have been reported to have anticancer properties, and so far about 30 compounds have been isolated from plants and tested in cancer clinical trials (9).