Matrine induces apoptosis of HepG2 cells. A: Apoptosis rate of HepG2 cells treated with matrine at the concentration of 0.5, 1.0 and 2.0 mg/mL, respectively, were significantly different from that in control group. Furthermore, the percentage of apoptotic cells increased when the concentration of matrine was increased. The data are expressed as mean ± SD (n = 3); B-E: Histograms of HepG2 cells incubated with matrine at the concentration of 0, 0.5, 1.0 and 2.0 mg/mL, respectively. Early apoptotic HepG2 cells were observed after incubated with matrine at the concentration of 0.5 and 1.0 mg/mL, the late apoptotic HepG2 cells were observed after incubated with matrine at the concentration of 2.0 mg/mL. bP < 0.001 vs control group.