Antitumor and immunomodulatory activities of a water-soluble polysaccharide from Chaenomeles speciosa

In this study, a water-soluble polysaccharide (CSP) was successfully purified from Chaenomeles speciosa by DEAE-Sepharose and Sephadex G-100 column chromatography. CSP had a weight-average molecular weight of about 6.3 × 104 Da and was composed of glucose (Glc), galactose (Gal), rhamnose (Rha) and arabinose (Ara) with a relative molar ratio of 4.6:1.3:0.8:0.5. CSP could not only inhibit the growth of S180 tumor transplanted in mice, but also increase the relative spleen index and body weight of tumor bearing mice. Moreover, concanavalin A (ConA) and lipopolysaccharide (LPS) induced splenocyte proliferation and peritoneal macrophage phagocytosis were also enhanced after CSP administration. Furthermore, CSP treatment could improve delayed type hypersensitivity (DTH) and promote the secretion of IL-2, TNF-α and IFN-γ in serum. The overall findings suggest that the antitumor effect of CSP is might be associated with its potent immunostimulatory activity.