Immunostimulating activity of pectic polysaccharide from Bergenia crassifolia (L.) Fritsch

The pectic polysaccharide named bergenan BC was obtained using extraction of the green leaves of Siberian tea Bergenia crassifolia (L.) Fritsch. by an aqueous ammonium oxalate. The polysaccharide obtained was proved to comprise mainly d-galacturonic acid, galactose, rhamnose, arabinose and glucose residues and appeared to be pectin. Delayed type hypersensitivity (DTH) reaction to aggregated ovalbumin (agOVA) was found to increase in mice that received bergenan solution (2 mg/mL) for 3 weeks. Bergenan BC was observed to enhance the uptake capacity of human neutrophils at a concentration 100 microg/mL and to stimulate the generation of oxygen radicals by mouse peritoneal macrophages in vitro. Bergenan BC was found to increase the spontaneous adhesion of peritoneal leukocytes and failed to influence adhesion stimulated by PMA or adhesion of peritoneal leukocytes incubated in the presence of 5 mm EDTA. Bergenan failed to show cytotoxic action. The viability of peritoneal leukocytes was estimated to be equal to 91% +/- 8% and 90% +/- 7%% in the control and in the pectin solution at a concentration of 1 mg/mL.Thus, bergenan was shown to possess immunostimulating activity in relation to DTH response in vivo and phagocytic activity in vitro.