Effectiveness of high-intensity interval training and high-protein diet on TNF-α protein level in colon tissue of obese male rats: The importance of diet modifying

Abstract

High-fat diets (HFDs) are a risk factor for obesity, insulin resistance, non-alcoholic fatty liver disease, hypertension, inflammatory bowel disease, and atherosclerosis. The present study aimed to investigate the effect of high-intensity interval training (HIIT) and high-protein diet (HPD) on interleukin-37 (IL-37) and tumor necrosis factor-alpha (TNF-α) protein levels in the colon tissue of obese male rats fed a high-fat diet (HFD). Forty obese male Wistar rats were randomly assigned into six equal groups: 1) HIIT, 2) HPD, 3) HIIT+ HPD, 4) Obese control 1 with HFD (Ct1), and 5) obese control 2 with breaking a HFD at the start of the study (Ct2). Eight rats were given a standard diet in the normal control group (NCt). Rats were sacrificed 48 h after the last intervention session and colon tissue was removed. The protein level of TNF-α was significantly lower in the HIIT, HPD, HIIT+ HPD, and Ct2 groups compared with the Ct1, with more lowering effects in the HPD and HIIT+ HPD and almost similar effects between the HIIT and Ct2 groups. No significant difference was observed in the IL-37 protein level between experimental groups. These findings suggest that HIIT, HPD, and HIIT+HPD may reduce colon inflammation through lowering of TNF-α inflammatory marker in colon tissue of obese rats receiving HFD. Although, the HPD alone and along with HIIT represent a more reducing effect than HIIT alone. However, breaking the HFD and replacing it with the standard diet was similar to the HIIT for reducing TNF-α. • HIIT, HPD, and HIIT+HPD led to a reduction in TNF-α protein levels in colon tissue of obese rats receiving HFD. • Replacing a HFD with the standard diet and HIIT without cessation of HFD had same effects on decreasing the TNF-α in rat colon. • A HPD alone and along with HIIT was more effective than HIIT without cessation of HFD on reducing the colon levels of TNF-α.