Alternations of salivary antioxidant enzymes in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with chronic systemic inflammation. Oxidative stress may play a role in the pathogenesis of SLE. An increase in free radicals or an impaired antioxidant defense system in SLE causes oxidative stress. Therefore, oxidative damage plays an important role in the pathogenesis of SLE. Variations in antioxidant activity have been previously studied in serum of patients with this disease. However, salivary factors have not been evaluated. Considering that saliva, the noninvasive biological fluid, could be a reflection of the state of health, the purpose of this study was evaluation of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) activity in the saliva of patients with SLE. During the course of the practical part of the project, 30 patients with SLE and 30 healthy controls were selected to donate their saliva samples. After centrifugation of un-stimulated saliva, biological activity of POD, CAT and SOD were evaluated on their appropriate substrates using spectrophotometric methods and the results were statistically analyzed. The results showed that activities of antioxidant enzymes SOD and CAT were significantly reduced in saliva of SLE patients as compared to controls. The results suggest that antioxidant status was impaired in the saliva of SLE patients, and antioxidant status of saliva could be one of the non-invasive markers for SLE.