Antidiabetic and Immunomodulatory Effects of Oleuropein and Vitamin C in Diabetic Male Rats

The present work was designed to study the antidiabetic and immunomodulatory effects of olive leaf polyphenol (Oleuropein) and vitamin C in diabetic male rats. Diabetes was induced by a single i.p. dose of STZ (40 mg/kg b.w.). Pure oleuropein compound (5 mg/kg b.w.) and vit. C (150 mg/kg b.w.) were orally administered once per a day for 15 days after diabetes induction. Oleuropein and vitamin C showed a significant role in attenuating the blood glucose, insulin, pancreatic amylase, and hexokinase alterations and caused an elevation of antioxidant enzymes in diabetic rats. Oleuropein and vitamin C showed a hematopoetic action as documented by the increase in RBC, Hb, Hct, PLt, decrease in WBC and improved RBC structure. Oleuropein and vitamin C significantly attenuated the oxidative status of diabetic rats. Oleuropein and vitamin C improved the different changes in some cytokines and interlukines and decreases the gene expression of TNF-, COX2, and caspase3 involved in apoptosis and inflammation. The immunohistochemical sections of pancreas in the diabetic rats treated with oleuropein and vitamin C showed a high intensity of insulin in -cells. Oleuropein as a natural active compound has antioxidant activity more or less like vitamin C to attenuate the effect of STZ-induced diabetes.