Effect of Methanol and Ethyl Acetate Leaf Extracts of Osbeckia octandra L. (Heen Bovitiya) on the Apoptosis and Migration of Human Oral Squamous Cell Carcinoma Cell Lines.

Background: Cancer has become a leading disease all over the world, and much attention is paid to prevention and management. Oral cancer is common in South Asian countries. Many therapeutic drugs are tested for the treatment of cancer. Osbeckia octandra is an endemic plant in Sri Lanka that is commonly used by traditional medical practitioners which has shown to possess anticancer properties. Objectives: The study was conducted to examine the anticancer potential of Osbeckia octandra chemical-based leaf extracts using an in vitro cell culture model of human oral squamous cell carcinoma (OSCC) cells and to delineate the possible molecular pathways involved in the process. Methods: Cells were cultured and treated with three concentrations (0.3, 3, and 30 μg/mL) of leaf extracts which were prepared using methanol (OMLE), ethyl acetate (OEALE), and hexane (OHLE) extraction protocols. The cell viability/cytotoxicity and cellular migration potentials were analyzed using standard assays. RNA was extracted from the treated cells and reverse transcribed to synthesize cDNA. Key genes involved in the BCL2 pathway were analyzed. Results: Cell viability was decreased with increasing concentrations in the OMLE and OHLE showing the dose-dependent impact of two extracts on cancer cell viability. 30 µg/mL indicated the lowest (p<0.05) cell viability while 3 µg/ml concentration in the OEALE reported the highest cytotoxicity. Moreover, 3 and 30 μg/mL of OMLE and OEALE significantly impaired the cell migration in the wound healing assay. Moreover, BCL2 gene expression was significantly altered by the 30 μg/mL concentration of the same extracts. Conclusion: The results of this study depict the methanol and ethyl acetate extracts of O. octandra possess anticancer activities on OSCC cells probably via BCL2 pathway. Further in-depth studies are warranted to examine the exact bio-active compounds and the underneath mechanisms.