Protective effects of salvianolate on microvascular flow in a porcine model of myocardial ischaemia and reperfusion

SummaryBackgroundMicrovascular reflow is crucial for myocyte survival during ischaemia/reperfusion injury.AimsWe aimed to assess if salvianolate, a highly purified aqueous extract from Radix salviae miltiorrhizae, could improve impaired microvascular reflow induced by ischaemia/reperfusion injury, using a porcine closed-chest model.MethodsLeft anterior descending coronary artery ligation was created by balloon occlusion for 2h followed by reperfusion for 14 days. Salvianolate was administrated intravenously for 7 days at low dose (5mg/kg/day), high dose (10mg/kg/day) or high dose combined with one 20mg intracoronary bolus injection just at the beginning of reperfusion. Control-group animals were only given the same volume of saline.ResultsAfter 14 days of reperfusion, animals treated with high-dose salvianolate showed improved myocardial perfusion assessed by real-time myocardial contrast echocardiography and coloured microspheres. The beneficial effect was further supported by increased capillary density and decreased infarct size. All these effects eventually resulted in well-preserved cardiac function detected by echocardiography. Moreover, we also demonstrated that salvianolate administration was associated with elevated superoxide dismutase activity, thioredoxin activity and glutathione concentration, and reduced malondialdehyde concentration, which, in turn, resulted in a significant decrease in terminal deoxynucleotide transferase-mediated dUTP nick end labelling-positive cells and an increased ratio of Bcl-2 to Bax expression.ConclusionIntravenous salvianolate at a dose of 10mg/kg/day for 7 days had significant beneficial effects on myocardial microvascular reflow, which were associated with decreased oxidative stress and apoptosis