Immunostimulating polysaccharides from Panax notoginseng.

OBJECTIVE

The main purpose of this study is to prepare and characterize polysaccharides from Panax notoginseng, investigate their effects on immune system in vitro in order to find new immunostimulants for the prevention and supporting treatment of infection and immunodeficiency related diseases.

METHODS

Polysaccharides were extracted with aqueous solution, separated with column chromatography. Their anticomplementary activities were investigated by using human serum and antibody-sensitized sheep red blood cells. Interferon-gamma and tumor necrosis factor inductive activities were studied by using isolated mouse spleen lymphocytes and peritoneal macrophages, respectively.

RESULTS

Four polysaccharides, homogeneous in gel-filtration chromatography, were prepared and designated PF3111, PF3112, PBGA11, and PBGA12. Component sugar analysis revealed that they are heteroglycans with MWs ranging from 37 kD to 760 kD, composed of glucose, galactose, arabinose, mannose, and xylose in different molar ratios. Fraction PBGA12 has the most anticomplementary activity which is mediated through both alternative and classical pathways. All the polysaccharides except PBGA11 induced the production of interferon-gamma in the presence of concanavalin A. They induced the production of significant amount of TNF-alpha in cell cultures.

CONCLUSIONS

The polysaccharides from P.notoginseng have immunostimulating activities in vitro.