The Effect of High-Intensity Interval Training and Coenzyme Q10 on the Expression of Hepatic IRS-2 and SREBP1 Proteins in Obese Male Rats

Background: Obesity contributes to the development of non-alcoholic fatty liver disease and insulin resistance (IR). In contrast, exercise and coenzyme Q10 (CoQ10) have been recommended to assist glucose control and IR. Objectives: This study aimed to investigate the effect of high-intensity interval training (HIIT) and COQ10 supplementation on hepatic IRS-2 and SREBP1 proteins in obese male rats. Methods: Forty-eight male Wistar rats after an obesity induction period were randomly assigned to six groups, including non-obese control (NOC), baseline obese control (BOC), CoQ10, HIIT, HIIT + CoQ10, and control. NOC and BOC groups were sacrificed at the beginning of the study period. After 12 weeks of intervention consisting of HIIT program (2 min running at 85% - 90% speed max interspersed with 2 min running at 45% - 50% speed max, 5 sessions per week) and/or CoQ10 supplementation (gavage-fed 500 mg.kg-1) protein content of hepatic SREBP1 and IRS-2 were measured by western blot analysis. Data were analyzed using independent t-test and two-way ANOVA at P < 0.05. Results: Comparison between non-obese and obese control groups indicated a significant difference in weight and Lee index (P < 0.001). Obesity induction elevated hepatic SREBP1c, while reduced IRS-2 protein content (P = 0.0001). Moreover, HIIT decreased hepatic SREBP1 level (P = 0.007), whereas increased IRS-2 content (P = 0.0001). However, CoQ10 supplementation had no significant effect on SREBP1 and IRS-2 (P > 0.05), and no interaction between treatments (HIIT×CoQ10) was observed (P > 0.05). Conclusions: HIIT positively regulates hepatic proteins involved in hepatic IR. However, CoQ10 has no effect on proteins involved in hepatic IR implication that its effect on glucose regulation and IR does not seem to be mediated by SREBP1 and IRS-2 proteins.