Effect of Chijongdan on sub G1 population in A549 cells. A549 cells were treated with 50, 100, 200 and 400 μg/ml of Chijongdan for 24 h and stained with propidium iodide (50 μg/ml) for 30 min at room temperature in dark. (A) The DNA contents of the stained cells were analyzed by the FACSCalibur flow cytometry. (B) Bar graphs represent percentages of apoptotic portion. All data were expressed as means ± standard deviation (SD). ***p < 0.001 vs. untreated control.