Structural characterization and in vivo antitumor evaluation of a hydro soluble polysaccharide from Flos Sophorae

This research was aimed to extract and purify a neutral high-molecular-weight polysaccharide, termed FSP, from Sophora japonica. This was followed by an investigation into its in vivo structural characteristics and antitumor activity. The chemical composition analysis and HPGPC results indicated that the total sugar content in FSP was 93.47 %, indicating a homogeneous molecular weight distribution. Ion chromatography analysis revealed that FSP was a neutral polysaccharide, primarily constituted by rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid and glucuronic acid, with a small amount of fucose. Methylation and NMR analysis showed that FSPs had α and β isomeric units, likely forming a complex arabinogalactan structure. In addition, SEM, AFM, XRD results showed that FSP was scattered and irregular, and the distribution was intertwined in disc and rod shapes. In this study, the effectiveness of FSP against tumors was evaluated using a mouse model implanted with H22 tumors. The results demonstrated that FSP induced apoptosis in tumor cells and disrupted the S phase of the cell cycle. Furthermore, immunohistochemical and qPCR analyses indicate that FSP's anti-tumor effects are due to Wnt signaling pathway inhibition and enhanced immunosuppressive activity. These findings suggest that FSPs can play a therapeutic and protective role in the cancer treatment.