Protein carbonyl content as a stable oxidative stress marker in type ii diabetes

Introduction: Carbonyl groups result from protein oxidation and their level in tissues and plasma is relatively a stable marker of oxidative damage. Proteincarbonyls in cells and tissues have beenobserved during oxidative stress.Increasein oxidative stressduring altered homeostasis of oxidants and antioxidants leads to deleterious effect on cellular components through oxidative damages to proteins, lipids, nucleic acids. Objectives:The present study is to evaluate the levels of protein carbonyls as a stable oxidative stress marker in type 2 diabetes without complications in comparison to the healthy controls. Methods: Three ml ofEDTA bloodwasused for estimations of HbA1c by HPLC, plasma glucose by Glucose oxidase peroxidase, plasma insulin by Chemiluminescence, and plasmaprotein carbonyl by Levine et al using 2,4-dinitrophenylhydrazine.A total of 60 diabetic patients and equal number of healthy individuals as controls were recruited in the study. Results: The Mean ± SD values of total protein carbonyl content was 0.70 ± 0.34nmol/ml, fasting plasma glucose 79.12 ± 11.74mg/dl, HbA1c 5.79±0.66%and plasma insulin 9.58±3.93mcu/ml in control group and the values in the diabetic group respectively were 1.68 ± 0.47nmol/ml, 182.58 ± 102.42 mg/dl, 8.86 ± 2.24%, 10.89 ± 5.37mcu/ml. The levels of protein carbonyl content, fasting blood glucose and Glycated hemoglobin were significantly increased in diabetic group compared to the controls. A positive correlation was observed between Protein carbonyls and glycemic status in controls and type 2 diabetes. Conclusion: Increased oxidative stress, indiabetic group, is doubtlessly induced by hyperglycemia. The present study indicatesthat an increased level of protein carbonyls wasobserved in generalized hyperglycemia. Since protein carbonyl formation was known to later the functional integrity of proteins, it could lead to the development of complicationsin uncontrolled diabetes and the carbonyls could acts as a stable oxidative stress marker in type 2 diabetes.