Background and Objective: the aim was to investigate the effects of 12 weeks of High Intensity Interval Training (HIIT) and curcumin supplementation on expression levels of FSTL1 and Smad7 and also Type I, III and IV collagens in rat model with myocardial infraction (MI). Methodology: 48 male rats were randomized into five groups of Reference, HIIT, Curcumin, Concomitant (HIIT+ Curcumin) and Control, following isoproterenol induced myocardial infarction. After Reference group execution in order to conform the MI, curcumin was administrated through oral gavage 15 mg/kg.day. HIIT sessions were conducted for five days per week, each session for 60 minutes, consisted of 10 bouts (each for 4 min) of running repetitions at 85-90% of v VO2 peak separated by 2 min active rest intervals between running periods. Left ventricular FSTL1, Smad7 and also type I, III and IV collagens expression level was detected by western blotting. Results: In all three intervention groups of HIIT, Curcumin and Concomitant, the cardiac weight was significantly higher (p=0.001, p=0.018 and p=0.001 respectively), while type IV collagen expression level was significantly lower (p=0.001 in any circumstances) than Control group. However, only in the Concomitant group, a significantly lower type III collagen (p=0.033) expression level as well as higher FSTL1 (P=0.001) and Smad7 (P=0.008) expressions were recorded, compared to the Control group. Conclusion: A diminished cardiac type IV collagen expression level in accompany with a zero mortality rate in all three interventions could likely imply on the safety of HIIT as well as curcumin supplementation to suppress post infraction myocardial fibrosis. However, only concomitant intervention could decrease infracted left ventricular type III collagen expression level, with an elevated FSTL1 and Smad7 expressions, which outlines their synergistic prescription to achieve better results. However, more researches remains to be done because of the lack of evidence and study limitations.
