Background: This study investigated the effects of aerobic exercise on cardiac SIRT3 and FOXO3 expression and inflammatory cytokines in rats with obesity induced by a high-fat, high-fructose diet.

Methods: The rats were assigned to three groups: control, high-fat/high-fructose diet (HFFD), and HFFD plus aerobic exercise (HFFD+Ex). Obesity was induced by 8 weeks of HFFD, followed by a 6-week progressive moderate-intensity aerobic treadmill training program (10-18 m/min, 10-30 min/day, 5 days/week; approximately 42-75% of individual Vmax) in the exercise group. Cardiac mRNA expression of SIRT3 and FOXO3 was determined by quantitative real-time PCR, while TNF-α, IL-1β, and IL-10 concentrations were measured using ELISA.

Results: HFFD induced obesity, dyslipidemia, and significant reductions in cardiac SIRT3 and FOXO3 expression compared with the control group. The exercised group showed significantly higher SIRT3 expression compared with the HFFD group, reaching levels comparable to controls, with a very large effect size (6.10). FOXO3 expression showed a 40% increase in the exercised group compared with the HFFD group, but this difference did not reach statistical significance (0.795), potentially due to limited statistical power with the sample size employed (62%). The exercised group also exhibited significantly lower circulating TNF-α and IL-1β concentrations and higher IL-10 levels compared with the HFFD group, indicating a systemic anti-inflammatory effect.

Conclusion: The findings show that aerobic exercise was associated with reduced cardiac inflammation and higher SIRT3 expression in the obese heart, suggesting a potential role for exercise in mitochondrial protection in the obese heart.