Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Biochemistry

The purpose of this study was to examine the effect of Amygdalin with and without zinc on HepG2 cell line ,to study the possible mechanism of action of amygdalin as a natural anti-cancer agent and to study the effect of natural milk thistle seed extract and the commercial silymarin drug (Legalon) on HepG2 cell line. The MTT method was used to evaluate the cytotoxicity of Amygdalin without zinc, Amygdalin with 20omol Zinc, Amygdalin with 800omol Zinc, M.T extract and Silymarin(Legalon) on HepG2 cell lines. Furthermore, the cell cycle distribution assay was determined by flow cytometry.Apoptosis was confirmed by Annexin V/PI double staining. Moreover, we evaluated the mean level of cytochrome c oxidase, P53, Bcl2, Bax, cytochrome c and caspase 3 level in all treated and untreated HepG2 cells. Amygdalin without zinc showed anti-HepG2 activity. Furthermore ,HepG2 cell line treatment with Amygdalin with 20omol Zinc and Amygdalin with 800omol Zinc showed a highly significant apoptotic effect than the apoptotic effect of Amygdalin without zinc. The cell cycle arrst at G2/M increased by increasing the concentration of zinc and M.T extract showed more cell cycle arrest at G2/M than Legalon. The percentage of early and late apoptosis increased by increasing the zinc concentration while Milk thistle showed more early and late apoptosis than legalon.All treated HepG2 cells showed significant increase in the mean levels of P53,Bax, cytochrome c and caspase 3 . while it decreased the mean level of Bcl2 and cytrochrome c oxidase. Both M.T extract and Silymarin showed a significant apoptotic effect on HepG2 via mitochondrion-dependent pathway

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