Antioxidants as inhibitors work to inhibit oxidation by reacting with reactive free radicals to form non-reactive free radicals that are relatively stable so that they can protect cells from the harmful effects of reactive oxygen free radicals. Medicinal plants are a precious gift of nature that plays an essential role in the health care system of developing countries and cure various diseases in the world. Red dragon fruit is rich in antioxidants needed by the human body. This study aims to determine the red dragon fruit extract (RDFE) has antioxidant activity. Extraction was carried out using 96% ethanol solvent by the maceration method. Measurement of MDA and SOD levels was carried out once at the end of the study using the spectrophotometer method and histopathological examination. The increased SOD activity in the extract group at a dose of 300 mg/kg BW was significantly higher (p<0.05) than that given maximum physical activity. The 200mg/kg BW rats group increased SOD activity significantly (p<0.05) compared to the negative group. The group of rats with a dose of 300 mg/kg BW had lower MDA activity than 200 mg/kg BW and 100 mg/kg BW in the negative group. The results obtained that red dragon fruit extract has an effect in increasing the activity of SOD levels and reducing MDA and the histological picture of the kidney given maximum physical activity, and the extract undergoes cell necrosis.