Abstract
Introduction: Ocimum Sanctum which is known as 'Tulsi ' in most of the local Indian languages is used for treating many of the day today illnesses in Ayurvedic Medicine. Recent evidence suggested Tulsi's usefulness as an antioxidant and anticancer agent and has been demonstrated on various cancer cell lines. However its antioxidant and cytotoxic activity has not been studied on KB cell lines. Hence an in-vitro study was designed with the aim to investigate the effects of Ethanolic extract of Ocimum Sanctum leaf (EEOS) on commercially available KB cell lines for its anticancer and antioxidant activity.
Material and Methods: O. Sanctum leaves were obtained and authenticated followed by which the leaves were shade dried, ethanolic extract was prepared and dry powder was stored in air tight container. Commercially available KB cell lines and L292 cell lines were procured and further cultured to use for anticancer and antioxidant assays. To check the anticancer activity, cytotoxic assays like MTT and neutral red assay using various concentration of extract was performed. For apoptosis, DAPI and double staining were performed. To determine the antioxidant property Phosphomolybdenum Assay (PMA), 2,2, Diphenyl-1 picryl hydrozyl radical scavenging activity assay (DPPH) and Ferric Ion reducing antioxidant power assay (FRAP) were carried out using various concentration of extract.
Results: EEOS demonstrated good anticancer and antioxidant activity on KB cell lines, and was compared with L292 cell lines. Cytotoxic activity increased in a time and dose dependent manner. With increase in concentration, cytotoxic effect was also increased and the effect was comparable with standard drug. Similar observation was made for antioxidant property of the extract in KB cell lines. There was decrease in cell viability and increase in apoptosis in KB cell lines when treated with extract.
Conclusion: EEOS showed good anticancer and antioxidant property . EEOS demonstrated decrease in cell viability and also apoptosis of KB cell lines suggesting its role in chemoprevention. Various phytochemicals present in Tulsi demonstrated antioxidant property. Further in vitro studies are to be done at molecular level to understand the effect on KB cell line, so that in future it can be used as a novel drug in prevention and treatment of oral cancer.

Key words: Ocimum Sanctum, Ethanolic extract, KB cell lines, Anticancer, Antioxidant, Oral Cancer.