Thymoquinone induces apoptosis via targeting the Bax/BAD and Bcl-2 pathway in breast cancer cells

Objective: Nigella sativa, commonly known as the black seed, has been used since ancient times in folk medicine, andits various therapeutic benefits have been mentioned in some ancient medical sources and confirmed by modernscience. Thymoquinone is the major compound and essential active ingredient of Nigella sativa seed oil.Thymoquinone has been reported to have high biological activity and broad therapeutic potential through severalmechanisms that affect cells including anti-oxidant, anti-inflammatory, and anti-tumor properties. Although it hasbeen widely reported that Thymoquinone inhibits cell growth and proliferation and stimulates apoptosis in varioustypes of cancer cells, the mechanisms and signaling pathways are not fully understood. The aim of this study was todetermine the effect of Thymoquinone on apoptosis in both tumor and non-tumor cells.Methods: In this study, breast cancer cell line (MCF-7) was used as tumor cells and Human Embryonic Kidney Cell line(HEK293) was used as non-tumor cells. Cells were treated with Thymoquinone and viability test performed by MTTassay.Gene expression of apoptosis markers such as Bax, BAD, Bcl-2, and p53 was determined by Real-Time PCR.HEK293 cells were used as non-tumor control.Results and Conclusion: Results suggest that Thymoquinone has a strong effect on cell proliferation and vitality.Thymoquinone has increased the expression of BAD, Bax genes which induce apoptosis and decreased the p53 gene inbreast cancer cells. Therefore Thymoquinone promotes apoptosis and enhances anti-cancer efficacy in breast cancercells.