Effect of vitamin E supplementation on the colon diabetic rats with special emphasis on the myenteric plexus: an immunohistochemical and scanning electron microscopic study

ABSTRACT

Diabetes mellitus is a metabolic disorder characterized by the development of microvascular pathologies, of which neuropathy is the most common. There are many reports on upper gastrointestinal symptoms; however, few studies on the mechanism underlying colonic symptoms were conducted. The aim of the study was to evaluate the effect of vitamin E supplementation on the colon of diabetic rats with special emphasis on the myenteric plexus. A total of 30 male albino rats were divided into two groups group I [control] and group II [experimental]. Diabetes was induced in group II rats using streptozotocin [35 mg/kg]. After 2 days, rats in group II were randomly classified into two subgroups subgroup IIa [diabetic rats] and subgroup IIb [diabetic rats treated with vitamin E supplementation [2%] added to rodent chow]. Twelve weeks after induction of diabetes, specimens from the proximal colon were collected and processed for light and scanning electron microscopic examination. Specimens for light microscopy were stained with H and E and antiglial fibrillar acidic protein [anti-GFAP] immunostain and then studied morphometrically. Subgroup IIa showed ulceration of the mucosa, disturbed shape and depth of crypts, reduction in thickness of the musculosa and surface area of the myenteric plexus as well as a highly significant decrease in the mean number of myenteric nerve cells and enteric glial cells. Vitamin E supplementation [group IIb] showed significant improvement in these changes. Vitamin E supplementation in rats with chronic diabetes mellitus has a protective effect on myenteric nerve cells and enteric glial cells and could improve the abnormal histological and morphometric changes in the colon wall of diabetic rats