An immunostimulatory polysaccharide (SCP-IIa) from the fruit of Schisandra chinensis (Turcz.) Baill.

A water-soluble polysaccharide named SCP-IIa was isolated from the water extract of the fruit of Schisandra chinensis (Turcz.) Baill by means of ethanol precipitation, deproteination, anion-exchange and gel-permeation chromatography. The molecular weight of SCP-IIa was ascertained via HPLC, and immuno-modulating effect was evaluated using the immunosuppressed model induced by cyclophosphamide. SCP-IIa was a homogeneous form of polysaccharide, with an average molecular weight of approximately 7700 Da. The detected parameters showed that SCP-IIa increased the thymus and spleen indices, as well as the pinocytic activity of the peritoneal macrophages in immunosuppressed mice. The splenocyte proliferation assay showed that SCP-IIa, in combination with Con A or LPS, positively affected splenocyte proliferation. Moreover, the polysaccharide promoted hemolysin formation. The results suggested that SCP-IIa was involved in immunomodulatory effects leading to the exploration for SCP-IIa as a potential immunostimulant.