Protective effect of Astragalus polysaccharide on endothelial progenitor cells injured by thrombin.

Several studies have demonstrated that Astragalus polysaccharide (APS) has a protective effect on endothelial cells damaged by various factors. To examine the role of APS in the endothelial inflammatory response, rat bone marrow endothelial progenitor cells (EPCs) were isolated by density gradient centrifugation and identified by immunohistochemistry, then we established a model of inflammatory injury induced by thrombin and measured the effects of APS on EPC viability and proliferation by MTT assays. We also assayed the effect APS had on the inflammatory response, by examining the nuclear factor kappa B (NF-κB) signaling pathway, as well as the expression of intercellular adhesion molecule-1 (ICAM-1), vascular endothelial growth factor (VEGF) and its receptors Flt-1 and KDR. Results demonstrated that EPCs were damaged by thrombin, and APS appeared to inhibit this damage. APS suppressed thrombin-induced ICAM-1 expression by blocking NF-κB signaling in rat bone marrow EPCs, and up-regulating expression of VEGF and its receptors. We believed that APS may be used to treat and prevent EPC injury-related diseases.