Cardioprotection of salvianolic acid B and ginsenoside Rg1 combination on subacute myocardial infarction and the underlying mechanism

Following myocardial infarction (MI), a series of structural and functional changes evolves in the myocardium, collectively defined as cardiac remodeling. The aim of present study was to investigate the cardioprotection of salvianolicacid B (SalB) and ginsenoside Rg1 (Rg1) combination against cardiac remodeling in a rat model at the subacute phase of MI and further elucidate the underlying mechanism. Rat heart was exposed via a left thoracotomy at the fourth intercostal space and MI was induced by a ligature below the left descending coronary artery. Hemodynamic assay was conducted using a Mikro-tipped SPR-320 catheter which was inserted through the right carotid artery into left ventricle.Myocardial infarct size was detected using 3,5-triphenyltetrazolium chloride (TTC) staining. Haematoxylin and eosin (HE) stain and picric sirius red stain were conducted for histopathological detection. Immunohistochemistry was used to detect the expression of α-smooth muscle actin (α-SMA) and gelatin zymography was used to evaluate the activities of matrix metalloproteinase-9 (MMP-9). Comparing with MI rats, 30 mg/kg SalB-Rg1 improved cardiac function verified by maximum rate of pressure development for contraction (+dp/dtmax, p