Endocrine Abstracts

According to the findings from the recent studies, the oxidative stress can be a cause for type 2 diabetes mellitus onset. In that context, the development of drugs with antioxidant effect to be used for prevention and treatment of the disease is of vital importance. The work was initiated to study the oxidative stress in the experimental diabetes and methods of its correction by means of natural antioxidants. In our study we used polyphenols isolated from the seeds of common grape vine (Vitis vinifera) and the leaves of upland cotton (Gossypium hirsutum), as well as the safflower (Carthamus tinctorius L.) extract. The antioxidant activity of the agents was assessed in vitro by ability to inhibit the adrenalin autoxidation; in tissue homogenates it was assessed by measuring concentrations of oxidates and activity of enzymes in the antioxidant system. Intensity of antioxidant activity of the agents above was compared to the one observed in quercetin, a flavonoid used as a reference product. All the agents under study demonstrated antioxidant effects close to the one produced by quercetin. To assess the hypoglycemic effect of the agents, in white outbred rats weighing 230–280 g type 2 diabetes mellitus was induced by three-fold intraperitoneal administration of diabetogenic dose of alloxan. When blood serum glucose was higher than 9–11 mmol/l the agents under study were administered to the experimental animals intragastrically in the doses providing optimal concentrations. Polyphenols isolated from Vitis vinifera and Gossypium hirsutum as well as Carthamus tinctorius L. extract were found to reduce the blood serum glucose in the diabetic animals by 50.0, 45.9% and 41.7%, respectively. Of note, gliclazide (Servier, France), the second generation sulfonylurea derivative, used as an oral hypoglycemic agent, reduced the parameter by 45.9%. The agents under study demonstrated both antioxidant and hypoglycemic effect. The hypoglycemic effect of agents under study observed in the type 2 experimental model could be associated with the antioxidant effect they produced.