Exogenous phosphatidylethanolamine induces apoptosis of human hepatoma HepG2 cells via the bcl-2/bax pathway

Figure 1 Effect of exogenous PE on the growth and apoptosis of human hepatoma HepG2 cells. A: Control group; B: 0.25 mmol/L PE; C: 0.5 mmol/L PE; D: 1 mmol/L PE; E: 48 h after treatment, inhibition of cell growth shown by MTT assay; F: Cell cycle in human hepatoma HepG2 cells shown by PI staining 24 h after PE treatment, with data showing the cell percentages at G1/G0, S and G2 phases; G: Apoptosis of human hepatoma HepG2 cells shown by annexin-V/PI staining 24 h after PE treatment, with data showing the percentages of non-affected, early and late apoptotic cells and necrosis. The results are given as mean ± SD from three experiments.

Figure 2 Effects of exogenous PE on the δΨm of human hepatoma HepG2 cells. A: Control group; B, C, D: Groups treated with 0.25, 0.5 and 1 mmol/L PE at 24 h; E: Flow cytometry analysis of cells with δΨm collapse in human hepatoma HepG2 cells shown by rhodamine staining at 24 h. The results are given as mean ± SD from three repeat experiments. ^bP < 0.01 vs control group.

Figure 3 Inhibitory effect of exogenous PE on bcl-2 expression in human hepatoma HepG2. A: Cells in control group; B: 0.25 mmol/L PE; C: 0.5 mmol/L PE; D: 1 mmol/L PE; E: Fluorescence intensity; F: 48 h after treatment and Western blotting. The results are presented as mean ± SD. Lane 1: Control group; lanes 2-4: 0.25, 0.5 and 1 mmol/L PE treatment groups. ^aP < 0.05, ^bP < 0.01 vs control group.

Figure 4 Inhibitory effects of exogenous PE on bax expression in human hepatoma HepG2 cells. A: Control group; B: 0.25 mmol/L PE; C: 0.5 mmol/L PE; D: 1 mmol/L PE; E: Fluorescence intensity, F: 48 h after treatment and Western blotting. The results are presented as mean ± SD. Lane 1: Control group; lanes 2-4: 0.25, 0.5 and 1 mmol/L PE treatment groups. ^aP < 0.05, ^bP < 0.01 vs control group.

Figure 5 Inhibitory effect of exogenous PE on caspase-3 expression in human hepatoma HepG2 cells. A: control group; B: 0.25 mmol/L PE; C: 0.5 mmol/L PE; D: 1 mmol/L PE; E: Fluorescence intensity, F: 48 h after treatment and Western blotting. The results are presented as mean ± SD. Lane 1: Control group; lanes 2-4: 0.25, 0.5 and 1 mmol/L PE treatment groups. ^aP < 0.05, ^bP < 0.01 vs control group.