Exploration of antioxidant and anticancer potential of essential oil of salvia plebeia RBR
Cancer is one of the major problems that accounts for millions of death worldwide per year. Breast cancer is the most commonly encountered cancer in the females. Chemotherapy and radiotherapy are the standard methods used in the treatment of cancer but these have various side effects also. Other complementary treatments based on plants and its products are used to lessen the side effects. Some essential oils are the potent source of the novel molecules and have been reported to have anticancer effect. In the present study, essential oil from Salvia plebeia has been screened for cytotoxic activity in vitro using MTT assay and has been observed to show inhibitory effect on the cancer cells with the increase in concentration against breast cancer cell lines, MCF-7 and MDAMB-231. The essential oil was observed to show IC50 at concentration 30?g/ml for MCF-7 cells and in MDAMB-231, IC50 was calculated to be 65?g/ml for 24 hours treatment. Essential oil was found to be effective against highly metatstatic MDAMB-231cells Exposure time effect was studied to know whether it has sustained effect or not and it was observed that essential oil had sustained effect at higher concentrations and longer exposure time was required to show sustained effect. Single cell gel electrophoresis (Comet assay) was used to find out its mode of action and it was observed to induce DNA damage in the cancer cells that might have resulted in cell death at various concentrations. Essential oil was observed to have antioxidant activity, which was studied using DPPH and hydroxyl radical scavenging assay. Various compounds like cayophyllene, alpha-humulene and cayophllene oxide were determined by GC-MS analysis. Cayophyllene was the major compound (46%). Some of the constituents might be responsible for anticancer activity of the oil. It has been concluded from the study that novel essential oil is very effective against breast cancer cells. This oil can be screened further against other cell lines and can be used as nutritional supplement.