Analysis of the inhibitory effect of safflower polysaccharide on HT29 colorectal cancer cell proliferation and its relevant mechanism

Objective: To explore the inhibitory effect of safflower polysaccharide on HT29 colorectal cancer cell proliferation and its relevant mechanism. Method: MTT assay was used to detect the inhibitory effect of safflower polysaccharide on HT29 colorectal cancer cell proliferation. Morphology of colorectal cancer cell apoptosis was observed. Cell cycle and apoptosis was assayed using Annexin V and PI double staining flow cytometry. Caspase-3 protein expression was detected by Western blot. Results: The inhibitory rate in every experimental group with different concentration was significantly higher than that in control group (p<0.05). The inhibitory rate was more significant along with the increasing concentration of the drug dose-dependently. IC50=201.908 mg/L. The concentration to HT29 cells was respectively 160 mg/L, 320 mg/L and 640 mg/L in experimental group. The HT29 cell cycle was affected. The main block was in HT29 cells G2/M phase, S phase. The apoptosis rate in experimental group with 160 mg/L, 320 mg/L and 640 mg/L was significantly higher than control group dosedependently (p<0.05). Caspase-3 protein expression in experimental group with 160 mg/L, 320 mg/L and 640 mg/L was significantly higher than control group (p<0.05). The expression increased along with the increasing concentration. This demonstrated that safflower polysaccharide could significantly upregulate Caspase-3 protein. Conclusion: Safflower polysaccharide could significantly inhibit HT29 colorectal cancer cell. The mechanism of it inducing HT29 cell apoptosis might have correlation with blocking cells in G2/M phase, S phase, and up-regulating Caspases-3 protein expression.