ABSTRACT This study aimed to evaluate the effect of Ilex paraguariensis infusion on redox state of Wistar rats submitted to high-fat and standard diet. Glutathione determination and lipid peroxidation in the hippocampus tissues and liver was performed, as well as the analysis of gene expression of superoxide dismutase, catalase and glutathione peroxidase by real-time polymerase chain reaction. The results from hippocampus showed that the groups fed with standard diet exhibited significant reduction of lipid peroxidation when supplemented with Ilex paraguariensis. The analysis from glutathione determination in the hippocampus showed a significant increase in glutathione activity in the group treated with high-fat diet and Ilex paraguariensis. In the liver, results showed no significant difference in both glutatione and lipid peroxidation analisys. Gene expression of superoxide dismutase, catalase and glutathione peroxidase showed that there was significant difference in the groups treated with high-fat diet and Ilex paraguariensis. In summary, the Ilex paraguariensis showed substantial potential for antioxidant activities.