Background and Aims:
In the current work, we studied the effects of exercise and stevia
rebaudiana (R) extracts on diabetic cardiomyopathy (DCM) in type 2 diabetic rats and their possible
underlying mechanisms.
Methods:
: Thirty-two male Sprague Dawley rats were randomly allocated into 4 equal groups; a) normal
control group, b) DM group, type 2 diabetic rats received 2 ml oral saline daily for 4 weeks, c)
DM+ Exercise, type 2 diabetic rats were treated with exercise for 4 weeks and d) DM+ stevia R extracts:
type 2 diabetic rats received methanolic stevia R extracts. By the end of the experiment, serum
blood glucose, HOMA-IR, insulin and cardiac enzymes (LDH, CK-MB), cardiac histopathology, oxidative
stress markers (MDA, GSH and CAT), myocardial fibrosis by Masson trichrome, the expression
of p53, caspase-3, α-SMA and tyrosine hydroxylase (TH) by immunostaining in myocardial tissues
were measured.
Results:
T2DM caused a significant increase in blood glucose, HOMA-IR index, serum CK-MB and
LDH, myocardial damage and fibrosis, myocardial MDA, myocardial α-SMA, p53, caspase-3, Nrf2
and TH density with a significant decrease in serum insulin and myocardial GSH and CAT (p< 0.05).
On the other hand, treatment with either exercise or stevia R extracts significantly improved all studied
parameters (p< 0.05). Moreover, the effects of stevia R was more significant than exercise (p< 0.05).
Conclusion:
Both exercise and methanolic stevia R extracts showed cardioprotective effects against
DCM and Stevia R offered more cardioprotective than exercise. This cardioprotective effect of these
lines of treatment might be due to attenuation of oxidative stress, apoptosis, sympathetic nerve density
and fibrosis and upregulation of the antioxidant transcription factor, Nrf2.
Long-term moderate intensity exercise alleviates myocardial fibrosis in type 2 diabetic rats via inhibitions of oxidative stress and TGF-β1/Smad pathway
