Oxidative stress and the role of antioxidative treatment in diabetes mellitus

It is well known that increased free radical (FR) production or decreased activity of antioxidative system (AOS) lead to an imbalance between pro-oxidants and antioxidants called oxidative stress (OxS). Oxidative stress is involved in numerous diseases including diabetes mellitus (DM). Elevated blood glucose level and other biochemical disorders accompanied with an inappropriate insulin secretion or improper insulin action are known features of DM. The antioxidative enzyme catalase (CAT) diminishes the production of hydrogen peroxide which is highly toxic for pancreatic cells. The increased activity of this enzyme found in DM type 1 (DMT1) patients signifies the importance of OxS in the pathogenesis of this autoimmune disease with excessive OxS. Additionally, hyperglycemia induces the generation of highly reactive FR and leads to the development of OxS which accelerates the development of DM and its complications associated to the decreased activity of AOS. It is important to point out that high doses of antioxidant agents could paradoxically have pro-oxidant effect. In this article, we present literature data related to relationship between OxS and DM with focus on non-enzymatic antioxidants as a potential novel therapeutical approach in treatment of DM. Dietary supplementation with antioxidant nutritional factors such as micronutrients and vitamins could be used as a novel strategy in both prevention and control of DM type 2 (DMT2).