Comparative studies of some antioxidants on the enhanced pancreatic insulin content in alloxan diabetic rats

ABSTRACT

Diabetes mellitus is a major endocrine disorder affecting nearly 10% of the population all over the world. Inspite of the introduction of hypoglycemic agents, diabetes and the related complications continue to be a major medical problem. Several studies in human and animal models have shown alterations in the antioxidant status in diabetes. Insulin is synthesized in the B-cells of the pancreatic islets and regulates the glucose levels. Hence, the present study was concerned with the evaluation of the effect of some antioxidants on the pancreatic insulin -immunoreactive cells intensity correlated with the number of B-cells and the area of islets. Experimental diabetes was induced by injection intraperitoneal of alloxan monohydrate [120mg/kg b. wt.]. After induction of diabetes, the islet B-cells of pancreatic tissue showed vacuolar degeneration, pyknotic nuclei and necrosis. In addition to disturbance of acinar pattern, there were also inflammatory cells in between the acini and the dilated ducts and congested blood vessels. The number of B-cells and the islets area were decreased compared with control animals. The quantitative immunohistochemical studies demonstrated significant decrease in the intensities of B-cells anti-insulin antibody reaction. On the other hand, the results illustrated that concomitant administration of garlic, green tea or zinc chloride, apparently reduced the B-cells damage. The number of B-cells and the area of islets were increased. Significant increase in the intensity of anti-insulin antibody positive reaction was noticed compared with control diabetic animals. Thus, garlic green tea or zinc administration were effective in protecting pancreatic tissue against diabetes in animal model, where they reduced remarkably the degree of B-cell damage and increased the insulin secretion