Anti-complement activity of polysaccharide B3-PS2 purified from Herba Scutellariae Barbatae

The polysaccharide B3-PS2 was extracted and purified from Herba Scutellariae Barbatae through chromatography of DEAE-cellulose and Sephacryl S-300 column.  Average molecular weight of B3-PS2 was about 1 100 kD.  It was composed of Glc, Gal and Ara in the ratio of 2.7∶2.7∶1.0, along with trace of Man, Rha, Fuc and Xyl.  B3-PS2 inhibited complement activation on the classic pathways with CH₅₀ value of (0.23 ± 0.03) mg·mL⁻¹.  The targets of B3-PS2 upon the complement system were C1r, C1s, C3 and C4.  These results suggested that anti-complementary activity of B3-PS2 was closed to its positive control heparin.  It strongly suggested that the polysaccharide B3-PS2 from Herba Scutellariae Barbatae could be a potential candidate in treating those complement-associated diseases.