Novel functional polysaccharides from Radix Polygoni Multiflori water extracted residue: Preliminary characterization and immunomodulatory activity.

The alkali-extractable polysaccharides (APMPs) were isolated from the water extracted residues of Radix Polygoni Multiflori, and further purified by DEAE-52 cellulose and Sephadex G-100 column chromatography to obtain a homogeneous polysaccharide (APMP-2) with molecular weights of 7724.8 Da. HPLC chromatography analysis identified that APMP-2 was a heteropolysaccharides and mainly composed of Galactose and Xylose with a molar ratio of 4.31: 1.06. It was shown that both APMP and APMP-2 were of activation effects on splenocytes and peritoneal macrophages, and also significantly restore the proliferation rate, phagocytic index and cytokine (IL-2 and TNF-α) production level of 5-FU-treated splenocytes/peritoneal macrophages in a dosage-dependent manner. The results suggested that polysaccharides presented in Radix Polygoni Multiflori water-extracted residues possessed immunomodulatory activity and could be used as potential immunomodulators, and this finding could be a reference for the utilization of Radix Polygoni Multiflori water extracted residues.