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 S. chinensis (Turcz.) Baill. ► SCP-IIa increased the thymus and spleen indices, as well as the pinocytic activity of the peritoneal macrophages in immunosuppressed mice. ► Moreover SCP-IIa promoted splenocyte proliferation and hemolysin formation.