Effects of a polysaccharide fraction from the roots of Bupleurum falcatum L. on experimental gastric ulcer models in rats and mice.

Effects of an acidic polysaccharide fraction, BR-2, from the roots of Bupleurum falcatum L., on HCl-ethanol, ethanol and water immersion stress-induced gastric lesions in mice and pylorus-ligated ulcers in rats have been studied. Oral administration of BR-2 at doses of 50 to 200 mg kg-1 inhibited the formation of the gastric lesions induced by necrotizing agents such as HCl-ethanol and ethanol, in a dose dependent manner. This protective effect was observed after oral, intraperitoneal, and subcutaneous administration of BR-2 (25-100 mg kg-1). BR-2 also inhibited the formation of gastric ulcers which were induced by water immersion stress or pylorus-ligation. Prostaglandin E2 in gastric juice from rats and in gastric mucosa from mice was not influenced by oral administration of BR-2. The protective action of BR-2 against HCl-ethanol-induced gastric lesions was not abolished by pretreatment with indomethacin (20 mg kg-1, i.p.). The amount of alcian blue binding to mucosa also increased after administration of BR-2 (100 mg kg-1, p.o.); however, the amount of hexosamine and N-acetylneuraminic acid in mucosa did not change significantly.