SC-III3 induced HepG2 cell cycle arrest. (A, B) The cells were treated with SC-III3 for 24 h, and the cell cycle was tested by flow cytometry after staining with propidium iodide. Cells in G0/G1, S, and G2/M phases were quantified and presented. (C, D) The cells were treated with SC-III3 for 48 h. (E) HepG2 cells were treated with SC-III3 for 24 h. The protein levels of Cyclin A, Cyclin B, Cyclin E and Cdk2 were analyzed with western blotting. Data were presented as means ± SEM of three separate experiments. The difference were significant at *p < 0.05, **p < 0.01 vs. control.