Correlation between oxidative stress and redox-active metals in type I diabetes

Abstract

Redox-active metals such as copper, iron, zinc and manganese are known to play an important role either as pro- or anti-oxidants in the phenomenon of oxidative stress. In performing their anti-oxidant roles, these metals specifically participate actively via interaction with specific amino acid residues, on the active sites of the antioxidant enzymes superoxide dismutase and catalase. The aim was to explore the nature of the relationship between these metals and oxidative stress levels in type I diabetics. In this work, the serum levels of malondialdehyde (MDA) and the serum concentration of four redox-active metals, zinc, copper, iron and manganese in type I diabetic patients and an in age-matched control group were assayed. The results revealed that MDA concentration was significantly elevated (p<0.05) in the diabetic group compared to their control counterparts. Serum iron was also significantly elevated in type I diabetics compared to its level in the control group. Both copper and manganese marginally decreased in type I diabetes relative to the control values. Zinc also decreased in type I diabetic patients compared to the concentration in the control. The Pearson’s Product Moment Correlation Coefficient (r) between oxidative stress (MDA) and metals concentrations revealed non-significant linear relationships. This study conclude that these metals do not act individually, but rather in synergy with other cellular factors such as the nature of the amino acids at the active sites of antioxidant metalloenzymes and their protein-bound stores in modulating the oxidative stress level in both normal individuals and Type I diabetes.