Beneficial effects of a polysaccharide from Salvia miltiorrhiza on myocardial ischemia–reperfusion injury in rats

In the present study, one water-soluble polysaccharide (SMP1) was isolated from the roots of Salvia miltiorrhiza. The cardio-protective potential of SMP1 was studied in the ischemia–reperfusion (I/R) model of rats in vivo. Results showed that 30 min of left anterior descending coronary artery occlusion (LAD) followed by 4 h of reperfusion markedly decreased myocardial superoxide dismutase (SOD), Na+–K+-ATPase and Ca2+–Mg2+-ATPase activities and increased myocardial malondialdehyde (MDA) level and serum activities of creatine kinase (CK) and lactate dehydrogenase (LDH) in I/R rats. An increase in infarct size and high apoptosis index of cardiac cell were also observed in IR rats. Administration of SMP1 400 and 800 mg/kg significantly reversed these biochemical parameters in the I/R rats to the normal levels in sham control rats. The infarct sizes and the percent of TUNEL-positive cells were found significantly decreased in SMP1-treated groups compared to I/R rats. Taken together, the present study clearly suggests SMP1 has a protective effect against myocardial I/R injury in rats by ameliorating oxidative stress and inhibiting myocardial apoptosis.