Protective effect of a polysaccharide from Salvia miltiorrhiza on isoproterenol (ISO)-induced myocardial injury in rats

In this study, we investigated the cardioprotective effect of one purified polysaccharide (SMP1) from Salvia miltiorrhiza on isoproterenol (ISO)-induced myocardial infarction (MI) in rats. ISO-treated rats showed severe myocardial damage and high lipid peroxidation level, as well as decreased endogenous myocardial antioxidant function. Pretreatment with SMP1 (100 and 400 mg/kg) for 30 days significantly increased the body weight, decreased the heart weight, attenuated the serum levels of creatine kinase (CK), creatine phospokinase-MB (CK-MB), dehydrogenase (LDH), alkaline phosphate (ALP), aspartate transaminase (AST), alanine transaminase (ALT), total cholesterol, triglyceride, and LDL-cholesterol (LDL-C), along with the increased concentration of HDL-cholesterol (HDL-C). In addition, SMP1 also enhanced myocardial superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities and elevated myocardial reduced glutathione (GSH) level, along with a decrease in thiobarbituric acid reactive substances (TBARS) concentration. Collectively, our results indicated that long-term oral administration of SMP1 offered significant protection against the damage induced by ISO in rat heart through enhancement of endogenous antioxidants and antihyperlipidemic activity.