Effect of Astragalus Polysaccharides on Chronic Atrophic Gastritis Induced by N-methyl-N′-nitro-N-nitrosoguanidine in Rats

This study investigated the effect and mechanism of Astragalus polysaccharides (APS) on chronic atrophic gastritis (CAG) induced by N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) in rats. Histomorphological, hormone-level, and immunohistochemistry experiments were used to investigate the gastric mucosal injury. Pathological changes were readily found in CAG rats. Compared to the control rats, the CAG rats showed significantly decreased plasma levels of gastrin and somatostatin while their motilin levels increased. Moreover, PGE2 in gastric tissue increased and serum sIgA decreased significantly, while the GSH/GSSG ratio showed no change. Immunohistochemical detection showed that the expression of EGFR, COX-2, and MMP-2 was higher in the gastric tissue of CAG rats. After APS treatment, the gastric morphology of CAG rats improved. APS increased plasma gastrin and somatostatin levels significantly but had no significant effect on the motilin level. APS also decreased tissue PGE2 and increased serum sIgA in CAG rats without affecting the GSH/GSSH ratio. This study suggested that APS had a beneficial effect on CAG rats by deregulating EGFR at its downstream effectors COX-2 and MMP-2.