The Effect of Eight Weeks of Moderate-Intensity Continuous Training and High Intensity Interval Training along with Citrus aurantium L on some Cardiac Mitochondrial Biogenesis Markers in the Heart Tissue of Elderly Rats

Introduction: Death from cardiovascular diseases is one of the leading causes of death in the elderly; Although the role of exercise and herbs in heart health has been reported, their cellular-molecular mechanisms are not yet well understood. Therefore, the aim of the present study was to investigate the effect of eight weeks of continuous exercise with moderate intensity and intense periodicity along with spring orange (Ca) consumption on some markers of mitochondrial biogenesis in the heart tissue of elderly rats. Method: In this experimental study, 49 elderly female rats (18-16 months old, weighing 280-320 g) were randomly assigned to (1) control, (2) sham (orange spring solvent), (3) Orange Spring, (4) Continuous Exercise, (5) Periodic Exercise, (6) Continuous Exercise + Orange Spring and (7) Periodic Exercise + Orange Spring were divided. Periodic exercises were performed with an intensity of 85-110% VO2max and a speed of 31-45 m / min and moderate-intensity continuous training (MICT) exercises with an intensity of 65% VO2max at a speed of 25-25 m / min; Orange spring consumption was 300 mg / kg / day peritoneally. Expression levels of peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α), sirtoin 1 (SIRT1) and sirtoin 3 (SIRT3) were measured in cardiac tissue. One-way analysis of variance with Tukey post hoc test was used to analyze the results (P≤0.05). Results: There was a significant difference in the values of PGC-1α, SIRT1 and SIRT3 in the study groups (P ≤ 0.05). The expression levels of cardiac PGC-1α and SIRT1 in the continuous, intermittent and orange spring exercise groups were not significantly different from the control group. But in the periodic training group, SIRT3 levels were significantly higher than the sham group (P ≤ 0.05). Also, the levels of PGC-1α, SIRT1 and SIRT3 in the groups of continuous training + spring orange and periodic training + spring orange were significantly higher than the control group (P ≤ 0.05). Increased expression of PGC-1α in the combined group of continuous exercise + spring orange was more favorable than the other groups. However, the increase in SIRT3 in exercise groups, especially periodic exercise, was more than other groups (P ≤ 0.05). Conclusion: Periodic and continuous exercise with orange spring extract seems to improve mitochondrial biogenesis in the heart tissue of elderly rats.