ABSTRACT
Objective: To investigate the effect and mechanism of lycorine apoptosis in the human Liver cancer cell line HepG-2. Methods: The inhibitory effect of Lycorine on HepG-2 cell growth was evaluated by the dimethylthiazol tetrazolium assay. Morphological apoptotic changes were characterized using an inverted microscope, Hoechst 33258 fluorescence staining and cell ultrastructure. The rate of cell apoptosis was determined by flow cytometry. Mitochondrial membrane potential and intracellular fluorescent intensity of MMP were detected using laser scanning confocal fluorescence microscopy. Expression of the proteins Bcl-2, Bax, cytochrome C, and Caspase-9 was assessed by western blotting. The activity of Caspase-3 protein was quantified using a Caspase-3 activity kit. Results: Lycorine inhibited the growth of HepG-2 cell line with an IC50 of 5.73 μmol/L. After 48 h lycoris radiata alkali treatment, morphological observation indicated that, the density of growth cell became thin, cell shrinkage and cell growth form an irregular shape, tend to appear apoptotic body. Moreover, with the drug concentration increases, the apoptotic body also gradually increased; Typical apoptosis characteristics of visible cells were observed under transmission electron microscopy. Compared with control group, with the increase of concentration of lycoris radiata alkali dosage, cell apoptosis rate increased, mitochondrial membrane potential decreased and MPTP membrane was open. After 48 h treatment of lycorine, relative activity of Caspase-3 increased in the HepG-2 cells, the expression of cytochrome C, Caspase-9 and Bax on the protein level were upregulated, and the expression of Bcl-2 protein was downregulated, and respectively into concentration dependence relationship, with statistical significance. Conclusion: Lycorine radiata had growth inhibition effect on human liver HepG-2 cells, and induced apoptosis of HepG-2 cells through mitochondrial pathway.