Anticancer activity of crude acetone and water extracts of Tulbaghia violacea on human oral cancer cells

Objective: To evaluate the anticancer activity of crude acetone and water leaf extracts of Tulbaghia violacea on a human oral cancer cell line(KB).Methods: The antioxidant activity of the leaf extracts was evaluated by using the DPPH assay while the anti-proliferative activity was assessed by using the MTT assay.The morphological characteristics of apoptotic cells were examined by using the dual acridine orange/ethidium bromide staining.Flow cytometry was used to evaluate the induction of multi-caspase activity and changes in the cell cycle.Results: The acetone and water extracts exhibited antioxidant activity in a concentration dependent manner.The extracts inhibited the growth of the KB cell line with IC_(50) values of 0.2 mg/mL and 1 mg/mL, respectively for acetone and water.Morphological changes such as cell shrinkage, rounding and formation of membrane blebs were observed in the treated cells.In acridine orange/ethidium bromide staining, the number of apoptotic cells increased as the concentration of the extracts increased.The activation of multi-caspase activity in KB cells treated with Tulbaghia violacea extracts was concentration dependent, leading to cell death by apoptosis and cell cycle arrest at the G_2/M phase.Conclusions: The acetone and water extracts of Tulbaghia violacea appear to have anti-cancer activity against human oral cancer cells and need to be investigated further.