Astragalus polysaccharides downregulates apoptosis in HepG2 cell through Wnt/β-catenin signaling pathway / 中草药

ABSTRACT

Objective To investigate the effects of Astragalus polysaccharides (APS) on HepG2 cell proliferation and apoptosis through Wnt/β-catenin signaling pathway. Methods Cell proliferation ability and cell viability was measured by MTT assay. Annexin V-FITC/PI stain and Caspase-3 activity assay were used to detect cell apoptosis. The changes of Wnt/β-catenin signaling pathway activity after treated by APS (100 and 200 mg/L) was measured by luciferase assay. The expression levels of β-catenin, c-myc, and Cyclin D1 were detected by qRT-PCR and Western blotting. Results As the concentration of APS increases, the cell viability of HepG2 cells decreased significantly (P < 0.05). Compared with control group, the cells apoptosis rates of in APS 100 and 200 mg/L groups were increased remarkably (P < 0.05); The relative activities of Caspase-3 in APS 100 and 200 mg/L groups increased significantly (P < 0.05); Meanwhile, the activity of luciferase in APS 100 and 200 mg/L groups decreased significantly (P < 0.05). The expression level of cleaved Caspase-3 was increased significantly. The mRNA 1evel of β-catenin, Cyclin D1, and c-myc in APS 100 and 200 mg/L groups were decreased significantly (P < 0.05), and the expression levels of Bcl-2, β-catenin, c-myc, and Cyclin D1 protein in APS 100 and 200 mg/L groups were decreased significantly (P < 0.05, 0.01). Conclusion APS promote the apoptosis of HepG2 cells through the down-regulation of Wnt/β-catenin signaling pathway, which leads to the inhibition of apoptosis-related gene Bcl-2 expression.