Investigation of cytotoxic, antimetastatic and antiangiogenic effects of ethanol extract of kohlrabi (Brassica oleraceae L. var. gongylodes L.) plant tuber on HepG2 cells

Cancer is a disease that results from the uncontrolled proliferation of cells that occurs with disruptions in the cell cycle. Over the years, due to the increasing incidence of cancer in humans, it has become more important to find a cure for this disease. It is clear that the various treatment methods used today have quite a lot of side effects for patients. This challenging treatment process leads scientists to find new treatments or new chemotherapeutic components. The use of plants as a therapeutic in diseases dates back to ancient times. Today, the interest in natural ingredients is increasing. There are many examples of cancer drugs whose active ingredient is derived from herbal sources. Brassicaceae vegetables, which are frequently found on our tables, also have important anticancer effects thanks to the various metabolites they contain. Based on this, it is aimed to obtain data that can contribute to the fight against cancer, taking into account the high content of anthocyanin, isothiocyanate, glucosinolate and phenolic component of the kohlrabi plant, which is a brassica vegetable. In this thesis, the cytotoxic, antimetastatic and antiangiogenic properties of ethanol extract obtained from the tubers of kohlrabi (Brassica oleraceae L. var. gongylodes L.) species were investigated. The obtained extract was applied to two different cell lines. The cytotoxic activity on the cells was examined by applying the WST-8 kit, the antimetastatic activity by the MMP-9 kit, and the antiangiogenic activity by applying the VEGF kit. The amount of caspase-3, an apoptotic marker, was analyzed using the caspase-3 kit. The results showed that the extract has a cytotoxic effect depending on the cell type, time and concentration. The extract is cytotoxic to HepG2 cells. According to the experimental results obtained, the IC50 value was calculated as 25.97 µg/mL for 24 hours, 23.39 µg/mL for 48 hours and 14.52 µg/mL for 72 hours as a result of the application of purple kohlrabi extracts on HepG2 liver cancer cell line. The IC50 value for 293T was not determined for 24 and 48 hours, but this value was determined as 25.73 µg/mL for 72 hours. The extract did not cause a statistically significant change on the amounts of VEGF and MMP-9. It was observed that the amount of caspase-3 increased. The results indicate that the kohlrabi extract has an apoptotic effect, but not an antiangiogenic and antimetastatic effect.