Antioxidant therapy attenuates oxidative stress in chronic cardiopathy associated with Chagas' disease.

Oxidative stress is common in inflammatory processes of many diseases, including the Chagas' disease, which is characterized by chronic inflammation. The present study is a sequence of a related publication [Oliveira TB, Pedrosa RC, Wilhelm Filho D. Oxidative stress in chronic cardiopathy associated with Chagas' disease. Int J Cardiol in press.] on the same subjects, which showed an increase in oxidative stress associated with the progression of the severity of the disease. Components of the antioxidant system and oxidative biomarkers present in the blood were measured in the same chronic chagasic patients (n=40), before and after vitamin E (800 IU/day) and vitamin C (500 mg/day) supplementation for 6 months. Antioxidant enzymes and contents of reduced glutathione in erythrocytes and plasma TBARS contents were analyzed in four groups of patients in different stages of chronic Chagas heart disease (n=10 each group, groups I, II, III, and IV) according to the Los Andes classification. After the combined vitamin supplementation, TBARS and protein carbonyl levels were decreased in plasma, whilst red cell GSH contents were increased in group I. The vitamin E contents found in the plasma were inversely related to the severity of the disease. No differences in gamma-glutamiltransferase activities were detected but the myeloperoxidase levels were decreased in patients at the initial stages, whilst seric nitric oxide levels were increased in groups II and III. After the antioxidant supplementation, CAT activity was increased in group II, GPx activity was increased in group I, GR activity was increased in groups I and II, whilst the GST activity was decreased in groups II, III and IV. The results clearly indicate that the antioxidant supplementation was able to counteract the progressive oxidative stress associated with the disease. New perspectives for the treatment of Chagas' disease might include an antioxidant therapy in order to attenuate the consequences of oxidative insult related to this disease.