Immunomodulatory activity of polysaccharide from Acanthopanax obovatus roots

The effects of the Acanthopanax obovatus polysaccharide (AOPS) as well as its combination with cyclophosphamide (CY) or prednisolone on immune responses were investigated in mice. AOPS (250 mg/kg i.p. x 5) increased the spleen weight and the number of spleen cells, and augmented the phagocytosis of peritoneal macrophages both in normal mice and in immunosuppressed mice. In a haemagglutinin assay AOPS increased the production of specific antibodies and antagonized the suppressive effect of CY. AOPS not only enhanced the degree of in vitro spleen cell-mediated red blood cells (SRBC) hemolysis (quantitative hemolysis of SRBC) but also restored the suppressive effect of CY completely. From these results, AOPS was shown to have an enhancing and a modulating activity on immune responses.