Abstract: Background and Objective: Breast cancer are a frequently diagnosed cancer in a female with a high mortality. This cell line study was planned to investigate the chemo protective efficiency of obovatol (OBO) in MCF-7 human breast adenocarcinoma cells. Materials and Methods: The MCF-7 cell treated with various concentrations of OBO (10, 25, 50 and 100 μM) to evaluate the anti-proliferative/ cytotoxicity study by MTT assay, pro-apoptotic activity by assessing caspase-3/9 (apoptotic markers) and protein expression of Bcl2 and Bax as well as cell cycle arresting property (cycle phases) by flow cytometry. Results: The MCF-7 cells supplemented with increased concentration of OBO displayed significant cytotoxicity/anti-proliferative activity with increased DNA fragmentation. Whereas, cell cycle phase analysis revealed considerable cell arrest after the addition of OBO by improving G0/G1and S phase. Moreover, the activities of caspase-3 and 9 were notably increased after treatment with OBO as well as the protein expression of Bax (pro-apoptotic protein) were markedly upregulated with a suppressed protein expression of Bcl2 (anti-apoptotic protein) were noted in MCF-7 administered with OBO in a dose-dependent manner. Conclusion: Overall, OBO showed potent chemopreventive activity by demonstrating its anti-proliferative, apoptosis and cell cycle arrest properties in a concentration-dependent fashion.