Protective Effect Of Icariin On Myocardial Ischemia - Reperfusion Injury And Its Mechanism

Purpose: The aim of this study was to determine whether icariin could potentially protect against myocardial ischemia reperfusion injury in rats and its mechanism.Material and method:Adult male Wistar rats(200-250 g) were used to prepare myocardial I/R model. Animals were kept at a constant temperature(22 ± 2 °C), humidity(40 ± 10 %), and a light/dark(12/12 h) cycle. Food and water were available ad libitum until the beginning of the experiment. Every effort was made to reduce the number of animals and their suffering.Myocardial I/R operations were prepared according to a previous procedure. Animals were randomly allocated into four groups(10 rats in each). Group A is sham operation group receiving normal saline without I/R, Group B is model group with I/R induced via ligation of LAD coronary artery for 30 min followed by 2 h reperfusion, while Group C received icariin(10 mg/kg, Melone pharma, Dalian, China) before reperfusion and Group D received icariin, 10 mg/kg with LY294002(0.3 mg/kg, Beyotime, Shanghai, China) before reperfusion. Briefly, the rats were anesthetized with Chloral hydrate 3 mg/kg(i.m.), and artificial respiration was immediately started with room air(volume 2.0 ml/100 g, rate 80 strokes/min). The chest was opened by middle thoracotomy. After pericardiotomy, a 4.0 black silk ligature was placed under the left aortic descending coronary artery, and the ends of the tie was threaded through a small vinyl tube to form a snare for reversible left aortic descending coronary artery occlusion. Before the reperfusion procedures, rats received an i.p. injection of icariin or LY294002 or vehicle(normal sterile saline). The myocardium was reperfused by loosening the snare for 2 h. Following termination of the experiment, serum was collected for LDH measurement. Hearts of the other six rats of each group were collected, washed with ice cold saline, immersed immediatelyin liquid nitrogen, and kept at-80 °C.CK, IMA and LDH Determination in Serum.Determination of Cardiac Infarct Size.Statistical Analysis Histopathological scores between groups were compared using sum of ranks test. Quantitative data from experimentswere expressed as mean ± SD, significance was determined by one-way analysis of AVONA followed by Dunnett’s test. P < 0.05 was considered statistically significant.Results: 1. Effect of Icariin Myocardial Infarct Volume in I/R Rats. 2. Effect of Icariin on LDH, and CK IMA. 3. Effect of Icariin Treatment Inhibited Apoptosis of Myocardial Cells After I/R. 4.Effect of Icariin on PI3K/AKT/e NOS Pathway.Conclusion: 1. Icariin Reduced Myocardial Infarct Volume in I/R Rats. 2. Icariin Reduces LDH, LDH, and CK Release. 3. Icariin Treatment Inhibited Apoptosis of Myocardial Cells After I/R. 4. Icariin could affect the PI3K/Akt/e NOS pathway contributing to the protective effect of myocardial cell.