Comparative analysis of the oxidative stress and antioxidant status in type II diabetics and nondiabetics: A biochemical study

BACKGROUND: Diabetes mellitus is a metabolic disorder characterized by hyperglycemia along with biochemical alterations of glucose and lipid peroxidation. It produces free radicals that induce lipid peroxidation which acts as an indicator for oxidative stress in the body. The widely used assay for lipid peroxidation involves measurement of malondialdehyde (MDA). Defensive system in the body consists of antioxidant enzymes which help in scavenging free radicals. Two such antioxidant enzymes are reduced glutathione (GSH) and superoxide dismutase (SOD). In this study MDA, GSH and SOD are assessed in serum and saliva of age- and sex-matched 33 diabetics and nondiabetics. OBJECTIVE: (1) To estimate the levels of MDA, GSH and SOD in saliva and serum of both diabetics and nondiabetics. (2) To correlate the levels of MDA, GSH and SOD in saliva and serum of both diabetics and nondiabetics. (3) To find if serum levels of MDA, GSH and SOD can be predicted from values of the same in saliva, in both groups. MATERIALS AND METHODS: Whole unstimulated saliva and venous blood samples obtained after 12 h of overnight fast were transported to the designated laboratory chosen for the study. Supernatants of the centrifuged samples were used for the assays of MDA, GSH and SOD. RESULTS: A significant correlation was obtained between serum and saliva values of MDA and GSH, hence the prediction of serum MDA and GSH was possible from their subsequent saliva values. Although the levels of serum and salivary SOD showed a weak positive correlation, prediction of SOD was not possible. CONCLUSION: Saliva can be used as a diagnostic tool for the estimation of MDA, GSH and SOD.