ABC | Volume 112, Nº2, February 2019

Original Article Arq Bras Cardiol. 2019; 112(2):154-162 Naderi et al Garlic and exercise increase cardiac angiogenesis Table 2 – Serum lipid profile in different groups after 6 weeks (Mean ± SEM, n = 7) Variants Control Diabetes Diabetes+ Garlic Diabetes+ Exercise Diabetes+Garlic +Exercise TG (mg/dl) 21.3 ± 2.9 87.8 ± 14.3 *** 42 ± 2.9 $$ 50.1 ± 9.3 $ 44.8 ± 3.7 $$ LDL(mg/dl) 41 ± 1.69 48.87 ± 1.21 *** 38.66 ± 0.61 $$$ 39 ± 0.81 $$$ 38.33 ± 0.76 $$$ HDL(mg/dl) 28.8 ± 1.07 18.25 ± 0.83 *** 28.16 ± 1.22 $$$ 26.66 ± 1.47 $$$ 27 ± 1.46 $$$ HDL/LDL 0.7 ± 0.03 0.36 ± 0.01 *** 0.72 ± 0.03 $$$ 0.67 ± 0.03 $$$ 0.7 ± 0.04 $$$ *** p < 0.001 vs control group and $$$ p < 0.001 vs diabetes group. Triglycerides (TG), High-density lipoprotein (HDL), Low-density lipoprotein (LDL) Little information is available about the expression of miR in the myocardium of diabetic rats in response to voluntary exercise. Interestingly, in the present study, we observed that garlic, voluntary exercise and a combination thereof increased the levels of miR-126 expression and angiogenesis in the myocardium. Cardioprotective effects of garlic have been reported in some studies related to improvement of antioxidant activities, 8 AMPK-mediated AKT/GSK-3 β /HIF-1 α activation, 27 and Akt-eNOS signaling pathways. 28 Moreover, in line with our results, da Silva et al. 6 showed that aerobic training in healthy rats increased cardiac miR-126 expression, which was possibly related to exercise-induced cardiac angiogenesis. 6 Furthermore, studies have demonstrated that exercise enhances angiogenesis in the heart both under healthy 29 and pathological conditions, 5,7 which highlights the positive effect of physical activity as a non-pharmacological tool in the treatment of cardiovascular disorders. Considering the increased expression of miR-126 following voluntary exercise, cardiac angiogenesis is possibly related to exercise-induced miR-126 expression and VEGF modulation, which upregulates angiogenic pathways such as MAPK and PI3K/Akt/eNOS. 6 An important hypoxia-induced miR, miR-210 is stimulated following hypoxia and HIF activation. 30 The elevation of miR-210 gene expression is evidence of hypoxic conditions in the cardiac muscle, in which hypoxia stimulates a number of physiological responses such as angiogenesis through HIF‑1 α -induced miR-210 expression. 31 MiR-210 upregulation is a major element of endothelial cell response to hypoxia, which leads to angiogenesis via its target gene Ephrin-A3. 17 The upregulation of miR-210 and VEGF has been shown to enhance myocardium angiogenesis in acute myocardial infarction in response to Huoxue Anxin Recipe. 32 Greco et al. 33 described that, in addition to hypoxia, hyperglycemia is another stimulator that upregulates miR-210 expression, which is observed in diabetes. 33 Osipova et al. 1 showed that miR-210 level was upregulated in plasma and urine of type 1 diabetic children, 1 as well as in cardiomyocytes and endothelial cells in diabetic patients. 33 In line with these studies, we showed that the induction of diabetes increased myocardial miR‑210 level, which was reduced by both garlic, voluntary exercise and a combination of both. Similarly, a recent study demonstrated that plasma miR-210 levels decreased in chronic kidney disease after acute exercise. 34 On the contrary, some studies have shown that miR-210 was not responsive during acute, exhaustive exercise, sustained aerobic exercise 11 and swimming 35 in the heart tissue. Furthermore, both garlic and exercise have been shown to be involved in providing good glycemic control and prevention against long-term diabetic complications. 3,8,19 Therefore, in the present study, the decrease of miR-210 expression back to normal levels seems to stem from glycemic control. Additionally, garlic extract-mediated angiogenesis probably occurs through the upregulation of the neovasculogenic c-kit protein expression and the activation of the PI3-K/Akt/NF- κ B signaling pathways, 36 which regulates e-NOS activation and NO production. 11 Hyperglycemia is currently considered to be primarily responsible for the alteration of lipid profile. In general, dyslipidemia is well confirmed in diabetes mellitus; it is known as a criterion for the diagnosis of type I diabetes and potential beta-cell lipotoxin. 37 It is worth noting that dyslipidemia is related to atherosclerosis and a risk of heart disease. 37 Dyslipidemia is possibly mediated by the alteration of LXR α expression in the liver and intestine, the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase pathways, and the consequent inhibition of eNOS activity, causing impaired angiogenesis. 15,38 In addition, dyslipidemia is related to decreased levels of circulating miR-126. 13 Riedel et al. 39 showed that exercise in patients with chronic heart failure significantly improved HDL-induced miR-126 expression. 39 In this study, treatment with garlic and voluntary exercise alone and together ameliorated lipid profile in the serum of diabetic rats, which is in agreement with previous studies. 6,9,40 Therefore, garlic and exercise have possibly modulated angiogenesis in the myocardium of the diabetic animals by modulating serum lipid profile and the expression of pro-angiogenic miRs. With regard to the limitations of this study, we did not measure other factors involved in angiogenesis. Further studies are necessary to clarify the pathophysiological mechanisms of garlic and voluntary exercise in the treatment of diabetic complications. Conclusion This study showed that garlic and voluntary exercise modulated serum lipid profile and the expression of miR‑126, miR-210, thus increasing angiogenesis inmyocardiumof diabetic rats. These findings suggest that garlic and voluntary exercise alone and combined may hold benefits in the treatment of diabetes. Author contributions Conception and design of the research, analysis and interpretation of the data and statistical analysis: Naderi R, Mohaddes G, Mohammadi M; acquisition of data: Naderi R, Ghaznavi R, Ghyasi R; obtaining funding, writing of the manuscript and critical revision of the manuscript for intellectual contente: Naderi R; Histological finding and 159