Comparison of the structural characterization and biological activity of acidic polysaccharides from Cordyceps militaris cultured with different media.

Two acidic polysaccharide fractions, CM-jd-CPS2 and CM-jd(Y)-CPS2, were isolated from the fruiting bodies of cultured Cordyceps militaris grown on solid rice medium and silkworm pupa, respectively, by hot-water extraction, ethanol precipitation and fractionation using ion-exchange column (DEAE-cellulose-52) and gel-filtration column (Sephadex G-100) chromatography. Their structural characterizations were performed by gas chromatography and fourier-transform infrared spectroscopy. Some differences existed between their structures, which indicated that culture media could influence the structure of polysaccharides of C. militaris. The antioxidant activities of CM-jd-CPS2 and CM-jd(Y)-CPS2 were evaluated by various methods in vitro. They had strong 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity and ferrous ion-chelating capacity, but moderate reducing power. The antioxidant activities of CM-jd(Y)-CPS2 were slightly higher than those of CM-jd-CPS2. These two acidic fractions were evaluated for proliferation of mouse splenocyte activity in vitro. They both possessed does-dependent mitogenic effects on mouse splenocytes, and could synergistically promote murine T- and B-lymphocytes induced by Con A and LPS. CM-jd(Y)-CPS2 exhibited stronger stimulatory activities upon immunomodulation than CM-jd-CPS2. These results are beneficial for the interpretation of the connection between polysaccharide structures and their biological activities.