Immune-stimulating properties of polysaccharides from Phellodendri cortex (Hwangbek)

Heteropolysaccarides were isolated from the Korean medicinal plant, Phellod endri cortex (Hwangbek), by hot water and alkali extractions. The extracted polysaccharides were fractionated into eight fractions and they are mainly composed of D-N-acetylglucosamine, D-galactose, D-mannose, and D-glucose. Among the polysaccharide fractions, Fr.-2 showed a potent B-lymphocyte-stim ulating activity in a system using polyclonal antibody forming cells in C57 BL/6XC3H mice at dosages of 2-10 mg. On the basis of their solubility in aq ueous ethanol, four fractions of Fr.-2-1 to Fr.-2-4 were further obtained f rom the Fr.-2, and Fr.-2-3 was divided into Fr.-2-3-1, 2, 3, and 4 by DEAE cellulose chromatography. The main activity was found in Fr.-2-3-2, which c ontained 100% (w/w) of carbohydrates and further purified to Fr.-2-3-2-2 by gel filtration chromatography using TSK Gel HW50S. Fr.-2-3-2-2, having a m olecular weight of about 230 kDa, showed the highest B-cell-stimulating act ivity and the half-maximal concentration for B-lymphocyte-stimulating activ ity was ca. 2.2 mu g/ml.