Determination of antioxidant, anticancerogenic and apoptotic effect of some plant extracts on cancer cell lines

Thesis Type: Postgraduate

Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2014

Thesis Language: Turkish


Principal Supervisor (For Co-Supervisor Theses): Belma Aslım

Co-Supervisor: Seniha Selcen Babaoğlu Aydaş


Cancer is a serious health problem growing rapidly all over the world. Epidemiological evidences confirm that plants are accepted as primary sources because of their great effect on decreasing the incidence of cancer, prevention of cancer deaths and their usage for drug improvement. In this study, water and methanol extracts of endemic Tanacetum albipannosum Hub.-Mor. & Grierson and Achillea sp. nova and common Centaurea depressa Bieb. were evaluated. We investigated the antiproliferative effect of 100, 250 and 500 μg/ml extract concentrations on colorectal adenocarcinoma cell lines HT-29, Caco-2 and cervical cancer cell line HeLa and their cytotoxic effects on healthy gingivial fibroblast cell line HGF-1. With increased concentration of plant extracts, antiproliferative effects have been found to increase. None of the plant extracts has cytotoxic effects on HGF-1 cells. The best antiproliferative effect was found on HeLa cells with the C. depressa methanol (500 μg/mL) and on HT-29 cells with the C. depressa water extract (500 μg/mL) (p<0.05). Total antioxidant capacity and superoxide dismutase (SOD) activity of the methanol and water extracts (250 and 500 μg/mL) on HT-29, Caco-2 and HeLa cells were also investigated. According to the data obtained from three cancer cells; plants showed high total antioxidant effect in parallel with the increasing doses just on HT-29 cells (p<0,05) A. sp. nova' s methanol extract (500 μg/mL) showed the highest antioxidant effect on HT-29 cells. C. depressa and T. albipannosum extracts didn't show any antioxidant effect on HeLa and Caco-2 cells. All plant extracts showed SOD activity on HeLa, and HT-29 cells as compared to the control but no effect on Caco-2 cells. High SOD activities were; A. sp. nova's water extract (500 μg/mL) on HeLa cells, and T. albipannosum' s water extract (500 μg/mL) on HT-29 cells (p<0.05). Antigenotoxic and genotoxic effects of methanol and water extracts (500 μg/mL) on lymphocytes were examined with comet assay. Extracts showed no genotoxic effect on lymphocytes. The best antigenotoxic effect was obtained with C. depressa water extract (p<0.05). Apoptotic effect of plant extracts on cancer cells was investigated. Water extract (500 μg/mL) of A. sp. nova showed the highest apoptotic effect on HT - 29 cells (p<0,05). Plants were scanned in terms of their flavonoids; apigenin, luteolin, biochanin A, rutine, quercetin, kaempferol, genistein and catechin. High values were obtained as compared with the literature; rutine, quercetin, kaempferol and apigenin. In conclusion we used the common C. depressa and endemic A. sp. nova and T. albipannosum species for the first time in terms of their anticancerogenic effects. This makes the research unique because of the benefits of finding a new anticancer agent. In addition the proof of these plant extracts with their anticancer effects and the mechanism underlying will provide the improvement of more effective, target focused, preventive and therapeutic medicine formulations. In this way it would be possible to increase the usage rate and efficiency of an agent whose mechanism of action is fully elucidated as a medicament.