Abstract:

Objective To investigate the protective effect of ginsenoside Rg1 on cardiac injury in the rats with severe acute pancreatitis （SAP）， and to elucidate the related molecular mechanisms. Methods The SD rats were randomly divided into control group， model group and Rg1 treatment group，with 6 rats in each group. The abdominal cavity of the rats in control group was closed after laparotomy； the rats in model group were retrogradely injected with 5% sodium taurocholate （0.15 μL·kg^－1） into the biliopancreatic duct to induce SAP after laparotomy； the rats in Rg1 treatment group were injected with Rg1 （4 mg·kg^－1） via the tail vein 30 min before operation of preparing the SAP model； the rats in control group and model group were injected with normal saline 30 min before operation. Enzyme linked immunosorbent assay（ELISA） method was used to detect the levels of serum tumor necrosis factor-α （TNF-α）， endotoxin， endothelin 1 （ET-1）， interleukin-1β （IL-1β） and the activities of serum creatine kinase-MB （CK-MB）， cardiac troponin I （cTnI） and mylase of rats in various groups. Ultrasound imaging system was used to detect the heart rate（HR），left ventricular end-systolic diameter （LVDs） and left ventricular end-diastolic diameter （LVDd） of rats in various groups and calculate the fractional shortening （FS）.Western blotting method was used to detect the expression levels of NADPH oxidase （NOX） 2 and NOX4， phosphorylated p38（p-p38），phosphorylated extracellular regulated protein kinase 1/2（p-ERK1/2） and phosphorylated c-Jun N-terminal kinase（p-JNK） proteins in myocardium tissue of rats in various groups. Results Compared with control group， the levels of TNF-α， endotoxin，IL-1β and ET-1 in serum of the rats in model group were significantly increased （P<0.05）； the activities of CK-MB，cTnI，and amylase were significantly increased （P<0.05）. Compared with model group， the levels of TNF-α， endotoxin，IL-1β and ET-1 in serum of the rats in Rg1 treatment group were decreased （P<0.05），and the activities of CK-MB，cTnI，and amylase were decreased （P<0.05）. Compared with control group， the HR and LVDs of the rats in model group were significantly increased （P<0.05），the LVDd had no significant difference（P>0.05），and the FS was significantly decreased（P<0.05）； compared with model group， the LVDs of the rats in Rg1 treatment group were significantly decreased （P<0.05），the LVDd had no significant difference（P>0.05），and the FS was significantly increased （P<0.05）.The Western blotting results showed that compared with control group， the expression levels of NOX2，NOX4，p-p38， p-ERK1/2 and p-JNK proteins in myocardium tissue of the rats in model group were significantly increased （P<0.05 or P<0.01）； compared with model group， the expression levels of NOX2，NOX4，p-p38， p-ERK1/2 and p-JNK proteins in myocardium tissue of the rats in Rg1 treatment group were significantly decreased （P<0.05）. Conclusion Rg1 has a protective effect on cardiac injury in the SAP rats，and its mechanism may be related to reducing myocardial tissue oxidative stress by inhibiring MAPK signaling pathway.

Key words: Ginsenoside Rg1, Severe acute pancreatitis heart injury, NADPH oxidase, Mitogen-activated protein kinase signaling pathway