The Effect of Aerobic Exercise and Bitter Orange Peel Extract on Oxidative Biomarkers and the Nrf2-Keap1 Signaling Pathway in the Quadriceps Tissue of Male Rats Fed a High-Fat Diet

Background: There appears to be a relationship between high-fat diet (HFD), inactivity, obesity, and many diseases. The effects of aerobic exercise (AE) on the improvement of oxidative stress have been confirmed, and the antioxidant effects of bitter orange peel (BOP) have been identified. Objectives: This study aimed to explore the synergistic effects of 4 weeks of AE and BOP extract consumption on oxidative biomarkers and the Nrf2-Keap1 signaling pathway in the quadriceps tissue of male rats fed an HFD. Methods: In this experimental trial, 30 male rats were randomly divided into 5 groups: (1) control-normal diet (CO-ND), (2) CO-HFD, (3) AE, (4) BOP, and (5) interaction of AE and BOP (AE-BOP). The BOP group received 60 mg (per kg of body weight) of BOP extract daily during the intervention period. The AE program with moderate intensity was implemented for 4 weeks, 5 days a week. Results: The nuclear factor erythroid 2 (NRF2) gene expression was significantly increased in the AE and AE-BOP groups, but this increase was not significant in the BOP group. The decrease in the KEAP1 gene expression in the studied groups was not significant. A significant decrease in MDA and a significant increase in the activity of superoxide dismutase (SOD) and catalase (CAT) enzymes and the glutathione peroxidase (GPX) gene expression were observed in the studied groups. Conclusions: Aerobic exercise and BOP reduced the oxidative stress caused by HFD by regulating the NRF2-KEAP1 signaling pathway. Therefore, these two interventions are recommended in the conditions of HFD.