Antitumor and antiangiogenic activity of Schisandra chinensis polysaccharide in a renal cell carcinoma model

The aim of this study was to determine the antitumor and antiangiogenic effects of the Schisandra chinensis polysaccharides (SCP) in selected renal cell carcinoma (RCC) cells and evaluate its potential mechanism of action. In vitro, endothelial growth factor (VEGF) secretion by Caki-1 was blockaded in response to SCP treatment for 48 h. In vivo, a significant tumor growth inhibition effect was observed after SCP administration for 4 weeks. Moreover, SCP treatment decreased the level of VEGF, CD31 and CD34 in RCC tumor tissues. Further analysis of the tumor inhibition mechanism indicated that the number of apoptotic tumor cells increased significantly; the expression of Bax and p53 increased; and the expression of Bcl-2 decreased dramatically in transplanted tumor tissues following SCP administration. These results indicated that the potential mechanisms involved by which SCP exerted its antitumor and antiangiogenic activity might be associated with the up-regulation of Bax and p53, downregulation of Bcl-2, as well as the reduction of VEGF, CD31 and CD34 in xenografted tumors. These findings demonstrated that the SCP is a potential antitumor agent for RCC treatment.