We next analyzed cell cycle progression in PANC-1 and SW1990 cells after treatment with PA-MSHA by flow cytometry. After 24 hours of PA-MSHA treatment, the population of pancreatic cancer cells in both the G0/G1 and G2/M phases was significantly lower than in the control group, while the population of cells in in S phase was significantly higher (p < 0.01) (Figure 5). These data indicated that PA-MSHA caused cell cycle arrest in S phase and induction of apoptosis.