ABSTRACT
Objective To explore the protective effect of ginsenoside Rb1 on the myocardial ischemia / reperfusion (I / R) injury in rats in vitro. Methods Totally 60 adult male SD rats were randomly divided into 6 groups:sham group,I / R group,ginsenosde Rb1 pretreatment groups(at the doses of 1 μmol / L,5 μmol / L,10 μmol / L and 20 μmol / L,respectively), 10 in each group. The Langendorff perfusion system was used to establish I / R model. The Lab Chart electrophysiological system was used to monitor real-time heart function by monitoring heart rate (HR), left ventricular development pressure (LVDP) and left ventricular development pressure (± dp / dtmax). TTC staining method was used to measure myocardial infarct size. The Western blotting were used to assay Beclin 1, LC3, p62 and Lamp 2 expression, respectively. The immunohistochemistry were used to assay Beclin 1 expression. Results Ginsenoside Rbl of all the four different concent rations improved the decrease of LVDP and ± dp / dtmax arising from myocardial I / R injury. Meanwhile, ginsenoside Rbl significantly decreased the area of cardial infarction. Ginsenoside Rb1 (10 μmol / L) precondition group protected the heart most significantly (P<0. 05). The expression of Beclin 1 with I / R increased significantly in the cytoplasm of cardiomyocytes. Moreover, Beclin 1 expression decreased after addition pretreatment with ginsenoside Rb1 (10 μmol / L) (P < 0. 05). Compared with sham group, we found that the autophagic flux was impaired in I / R group which the expression of Beclin 1, LC3 and p62 increased significantly, as well as the expression of Lamp 2 decreased significantly. On the other hand, pretreatment with ginsenoside Rb1 (10 μmol / L) could reverse impaired autophagic flux (P < 0. 05). Conclusion Ginsenoside Rbl demonstrates pharmacological preconditioning effect and protects against myocardial I / R injury by improving damaged-autophagy flux, the dose of 10 μmol / L precondition protectes the heart most significantly.