Introduction and Purpose: An increase in the number of defective mitochondria and their persistence can lead to apoptosis and necrosis of cells. Regular physical exercise along with time-restricted eating (TRE) can play an important role in improving mitochondrial damage and function. Therefore, the aim of this study was to investigate the effects of 4 weeks of continuous aerobic exercise and fasting on the expression of some genes involved in mitophagy, including PINK1 and BNIP3, and some factors influencing liver health such as liver enzymes ALT and AST, and the lipid profile in healthy rats.
Materials and methods: his was an experimental study. Thirty healthy male Wistar rats, 18–20 weeks old, with an average body weight of 330.40 ± 25.34 grams, purchased from the Pasteur Institute of Iran, were randomly assigned to six groups of five: Control, Fasting, 3 days of exercise, 5 days of exercise, Fasting + 3 days of exercise, Fasting + 5 days of exercise. The exercise program was performed on a treadmill for 4 weeks, 3 or 5 days per week, for 45–60 minutes per session. Tissue sampling was conducted 24 hours after the last exercise session following a 14-hour fasting period, and blood samples were collected directly from the heart. One-way ANOVA and LSD post-hoc tests were used for data analysis.
Results: Weight, cholesterol, and ALT levels significantly decreased in all experimental groups compared to the control group (P≤0.05). The groups "fasting + 3 days of exercise" and "fasting + 5 days of exercise" showed greater reductions in these indices compared to other groups, but there was no significant difference between the two. Triglyceride levels also significantly decreased in all groups compared to the control group, with no significant differences observed among the other groups. AST levels significantly decreased in all groups compared to the control group (P≤0.05), with greater reductions observed in the "3 days of exercise," "5 days of exercise," "fasting + 3 days of exercise," and "fasting + 5 days of exercise" groups. Again, no significant difference was found among these groups.
The PINK1 marker significantly decreased in the "5 days of exercise," "fasting + 3 days," and "fasting + 5 days of exercise" groups compared to the control and fasting groups (P≤0.05), with no significant difference among the remaining groups. The BNIP3 marker showed a significant increase in the "3 days of exercise," "5 days of exercise," and "fasting + 3 days of exercise" groups compared to the control group (P≤0.05). The "5 days of exercise" group had a greater increase compared to the "fasting + 3 days of exercise" group. No significant differences were observed between the fasting and fasting + 5 days of exercise groups compared to the control.
Discussion and Conclusion: Four weeks of continuous aerobic exercise combined with fasting can positively impact liver health under normal mitophagy conditions by lowering lipid profile markers and increasing BNIP3 gene expression.