Abstract
Cancer immunotherapy is quickly growing and can now be viewed as the "fifth column" of cancer treatment. In addition, cancer immunotherapy has shown promising results with different kinds of cancers and may be used as a complementary therapy with various types of treatments. Thus, "immuno-oncology" is showing astounding advantages. However, one of the main challenges that face this type of therapy is that cancer cells can evade immune system elimination through different mechanisms. Many studies were done to overcome this issue including adding immune stimulants to generate synergistic effects or by genetically modifying NK cells themselves to be stronger and more resistant. Nigella sativa, also known as black cumin, is a well-known example of a widely applicable herbal medicine. It can effectively treat a variety of diseases, such as hypertension, diabetes, bronchitis, gastrointestinal upset, and cancer. The anticancer qualities of Nigella sativa appear to be mediated by an immune-modulatory effect that stimulates human natural killer (NK) cells. These are a type of lymphocyte and first line of defense against pathogens. Objectives. In this study, we investigated the therapeutic effect of thymoquinone, a major component of Nigella sativa, on the cytotoxic pathways of NK cells. Methods. NK cells were cultured with breast cancer cell line Michigan Cancer Foundation-7 (MCF-7); and were treated with Thymoquinone. The cytotoxicity of NK cells on cancer cells was measured. The cultured media were then collected and measured via enzyme-linked immunosorbent assay (ELISA) for concentrations of perforin, granzyme B and interferon-alpha (IFN-alpha). Results. The cytotoxic effect of NK cells on tumor cells was increased in the presence of thymoquinone, with an increased release of perforin, granzyme B, and IFN-alpha. Conclusion. Thymoquinone promotes the cytotoxic activity of NK cells against breast cancer MCF-7 cells.