β-Elemene Inhibits Cell Proliferation by Regulating the Expression and Activity of Topoisomerases I and IIα in Human Hepatocarcinoma HepG-2 Cells

Figure 4

β-ELE induces cell cycle arrest and apoptosis in HepG-2 cells. (a) The effect of β-ELE (β-Elemene) on the cell cycle of HepG-2 cells after 24 h. (a1) Control group (without β-ELE). (a2) Experimental group (β-ELE 20 μg/mL). (a3) Experimental group (β-ELE 40 μg/mL). (a4) Experimental group (β-ELE 60 μg/mL). After treatment with different concentrations of β-ELE (0, 20, 40, and 60 μg/mL) for 24 h, a significant S phase arrest in HepG-2 cells was observed. The percentage of cells in S phase was %, %, and % at 24 h when treated with β-ELE at 20, 40, and 60 μg/mL, respectively. These values were apparently higher than that of the control group after 24 h (%, ). (b) The effect of β-ELE (β-Elemene) on the cell cycle of HepG-2 cells after 48 h. (b1) Control group (without β-ELE). (b2) Experimental group (β-ELE 20 μg/mL). (b3) Experimental group (β-ELE 40 μg/mL). (b4) Experimental group (β-ELE 60 μg/mL). After treatment with different concentrations of β-ELE (1, 20, 40, and 60 μg/mL) for 48 h, a significant S phase arrest in HepG-2 cells was observed. The percentage of cells in S phase was %, %, and % after 48 h when treated with β-ELE at 20 μg/mL, 40 μg/mL, and 60 μg/mL, respectively. These values were apparently higher than that of the control group at 48 h (%, ). (c) β-Elemene induces human hepatocarcinoma HepG-2 cell arrest at S phase. After treatment with different concentrations of β-ELE (0, 20, 40, and 60 μg/mL) for 24 h and 48 h, a significant S phase arrest in HepG-2 cells was observed. The percentage of cells in S phase was %, %, and % after 24 h and %, %, and % after 48 h when treated with β-ELE at 20, 40, and 60 μg/mL, respectively. These values were apparently higher than those of the control group at 24 h (%, ) (Figure 4) and 48 h (%, ) (Figure 5), which suggests that β-ELE treatment leads to an accumulation of HepG-2 cells in S phase (). (d) The effect of β-ELE (β-Elemene) on the apoptosis of human hepatocarcinoma HepG-2 cells. After treatment with different concentrations of β-ELE (20, 40, and 60 μg/mL) for 24 h and 48 h, the percentage of apoptosis cells was %, %, and % after 24 h and %, %, and % after 48 h. These values were significantly higher than those of the control group at 24 h (%, ) and 48 h (%, ) and showed dose and time dependence ().

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