Interactive Effects of Swimming Training and Cinnamon Supplementation on Changing Cardiac miR-133a and miR-21 in the Streptozotocin-Induced Diabetic Rats

This study aimed to review the synergistic effects of swimming training (ST) and cinnamon supplementation (Cin) on changing cardiac miR-133a and miR-21 in streptozotocin-induced diabetic rats.  A total of 32 diabetic rats were selected as 1) ST+ Cin, 2) Cin, 3) ST and 4) diabetic control (DC) groups, and eight healthy rats were selected as the HC group. Groups 1 and 3 swam three sessions per week and 2-22 minutes each session for eight weeks. Groups 1 and 2 received 200mg/kg/day of aqueous Cin extract. qReal Time PCR method was used to measure the miR-21 and miR-133a gene expression in heart tissue.  MiR-133a and miR-21 gene expression in Cin, ST, and ST+Cin groups increased compared to the DC group (P=0.001), and miR-133a gene expression in the ST+Cin group enhanced compared to Cin and ST groups (P=0.001). MiR-21 gene expression in ST and ST+Cin groups increased compared to the Cin group. In addition, miR-21 gene expression in the ST+Cin group raised compared to the ST group (P=0.001).  Although exercises lead to cardiac adaptations by creating oxidative stress, cinnamon can increase miR-133a as a cardio-protective agent and modulate miR-21 as a marker of cardiac damage. Therefore, cinnamon should be used along with exercises in cases of diabetes and heart disease.