In vitro Cytotoxic Activity of Nigella sativa L. on Human Malignant Melanoma Cell Lines

Nigella is a medicinal plant that has various pharmacological properties. It is widely used in folk medicine to treat many diseases in the world. It was aimed to investigate the essential oils Nigella sativa L. on two human melanoma cells (A-375 and A-2058 cell lines). In this study, two different cancer cell lines (A-375and A-2058 cell lines) and one normal cell culture (vero cells) were used. Firstly, the non-toxic concentrations the essential oils of Nigella sativa L. were determined on normal cells (Vero cell line). And then, the cytotoxicity test were applied at these non-toxic concentrations. The cytotoxic activity of the essential oils of Nigella sativa L. on the cell lines was measured by MTT and Trypan blue assays. The chemical components analyses of the Nigella sativa L. oils were carried out by GC-MS. Medically important various components of Nigella sativa L. were determined in the GC-MS analysis. Some of these components are as follows; anethole (22.97%), thymoquinone (21.36%), α-thujene (6.22%), longifolene (5.76%), trans-isoeugenol (3.55%), carvacrol (2.23%). A total of 24 compounds were identified. The essential oils of Nigella sativa L. were found to inhibit the cell proliferation of human malignant melanoma cells. The IC50 values of the essential oils of Nigella sativa L. It were investigated as compared with a standard drug (methotrexate). Statistically significant decrease on the cell proliferations was found in the cells treated with the essential oils of Nigella sativa L. It was found to be non-toxic on normal cells (on Vero cell line) at the effective concentrations of the essential oils. While the non-toxic concentrations of essential oils on Vero cell line were found to be 12.5 µg/ml, the effective concentrations for A-375 and A-2058 cell lines were as 1.56 µg/ml and 3.12 µg/ml, respectively. In conclusion, the essential oils of Nigella sativa L. were found to be significantly inhibited the cell proliferation on the human melanoma cells. The effect may arise from the components situated in the structure of Nigella sativa L. such asanethole, thymoquinone, α-thujene, longifolene, trans-isoeugenol and carvacrol. These components of this plant have been found promising in the treatment for human melanomas. But further studies, especially further animal studies should be needed to explain the action mechanisms of these components.