Role of some antioxidants in protection from the structural damage produced in the stomach and intestinal mucosa of diabetic rats. Histological and histochemical studies

ABSTRACT

Diabetes Mellitus affects the structural and functional integrity of many organ systems. Only a few previous studies have discussed these effects on the stomach and small intestine. In the present study, the effects of Alloxan-induced diabetes as well as the effect of some antioxidants [melatonin, chromium, a-tocopherol, ginseng and green tea] in reducing these effects on the mucosa of both stomach and small intestine were investigated. The morphological examination of the stomach and intestinal mucosa in diabetic rats revealed the presence of marked erosion and necrosis of mucous neck cells and parietal cells, while peptic cells showed vacuolar degeneration. The lining epithelial cells of the villi of the small intestine showed severe degeneration with marked hypertrophy and swelling of goblet cells. The tunica propria showed diffuse inflammatory cellular infiltration. Examination of the mucopolysaccharide content in these specimens using PAS reaction revealed a decrease in the positivity of the reaction in the luminal surface of epithelial cells of diabetic rats as compared with control non-diabetic rats, but an intense reaction in the gastric pit cells. Examination of intestinal mucosa revealed marked increase in goblet cells' reaction. Examination of the protein content in the same specimens using bromophenol blue stain showed vacuolar degeneration which was observed in the epithelial cells of both stomach and small intestine accompanied by decreased protein content. Examination of the stomach and small intestinal mucosa of diabetic rats treated with antioxidants, revealed marked improvement and normalization of the luminal surface of epithelial cells and gastric mucosal cells. There were detectable repair of the villus epithelium of the small intestine and normalization of the PAS positive reaction and protein content in both stomach and intestinal mucosa