Twelve weeks of treadmill exercise training with green tea extract reduces myocardial oxidative stress and alleviates cardiomyocyte apoptosis in aging rat: The emerging role of BNIP3 and HIF‐1α/IGFBP3 pathway

In this study, we consider the effect of treadmill exercise training, green tea extract, and combination of exercise training with green tea extract, in aging rat cardiac myocytes apoptosis markers (i.e., HIF-1α, BNIP3, Bax, IGFBP3, Bcl-2, caspase-3, MDA, GPx, Bax/Bcl-2 ratio, and hematoxylin and eosin). Twenty-four rats (male, Wistar) were divided into four groups: (I) control (n = 6), (II) green tea extract (n = 6), (III) exercise (n = 6), and (IV) exercise + green tea extract (n = 6). Exercise groups performed 12 weeks of running on a rodent treadmill at 17-27 m.min^-1 (60-75% vo2peak) for 5 days per week. Green tea extract involved 300 mg.kg^-1 , 5 days per week for 12 weeks. After being euthanized, the blood and heart were collected for glutathione peroxidase (GPx) activity, malondialdehyde (MDA), HIF-1α, BNIP3, insulin-like growth factor-binding protein-3 (IGFBP3), Bax, Bcl-2, caspase-3, Bax/Bcl-2 ratio, and hematoxylin and eosin level measurements. Compared to control, the ANOVA demonstrated significant effects of green tea extract (F = 14.646 to 32.453, p = .009 to .001, η = 0.295 to 0.715) and exercise training (F = 9.213 to 133.828, p = .007 to .001, η = 0.315 to η = 0.870) on HIF-1a, BNIP3, Bax, IGFBP3, Bcl-2, caspase-3, MDA, GPx, and Bax/Bcl-2 ratio. However, the combination of green tea extract and exercise had no effect on the aforementioned apoptosis markers when compared to isolated green tea extract or isolated exercise (F = 0.002 to 4.068, p = .057 to .968, and η = 0.001 to 0.169). PRACTICAL APPLICATIONS: Isolated exercise training and green tea extract may provide a cardioprotective effect on aging-induced apoptosis through the downregulation of HIF-1α, BNIP3, and IGFBP3 in the heart muscle. However, further research is needed to clarify the effects of combining exercise and green tea.