Abstract:

Objective To discuss the effect of ligustilide on the cardiac function and angiogenesis in the rats with heart failure，and to clarify its regulatory effect on protein kinase D1 （PKD1）/hypoxia-inducible factor-1α（HIF-1α）/vascular endothelial growth factor （VEGF） pathway. Methods The SD rats were randomly divided into sham operation group， model group， ligustilide group， PKD1/HIF-1α/VEGF signaling pathway inhibitor CID755673 （CID） group， and ligustilide+CID group. The heart failure rat model was established by ligation of the left anterior descending coronary artery. The rats in ligustilide group were injected intravenously with 20 mg·kg^－1 ligustilide， the rats in CID group were injected intraperitoneally with 50 mg·kg^－1 CID， and the rats in ligustilide+CID group were injected intraperitoneally with 50 mg·kg^－1 CID followed by intravenous injection of 20 mg·kg^－1 ligustilide， once per day for 4 consecutive weeks.The cardiac function indexes of the rats in various groups were detected by echocardiography；the percentages of myocardial infarction areas of the rats in various groups were detected by 2，3，5-triphenyltetrazolium chloride （TTC） staining； the pathomorphology of myocardium tissue of the rats in various groups was observed by HE staining； the expression levels of PKD1， HIF-1α， CD31， and VEGF mRNA and proteins in ischemic area of myocardium tissue of the rats in various groups were detected by real-time fluorescence quantitative PCR （RT-qPCR） and Western blotting methods. Results Compared with sham operation group， the rats in model group and CID group had altered myocardial cell morphology， increased intercellular gaps， disorganized arrangement， visible muscle fiber breaks and inflammatory cell infiltration； the rats in ligustilide group and ligustilide+CID group had relatively orderly myocardial fiber arrangement， fewer myocardial fiber breaks and decreased number of inflammatory cells. Compared with sham operation group， the left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （LVFS） of the rats in model group were decreased （P<0.05）， the left ventricular end-systolic diameter （LVESD） and left ventricular end-diastolic diameter （LVEDD） were increased （P<0.05）， and the expression levels of PKD1， HIF-1α， CD31，and VEGF mRNA and proteins in myocardium tissue were decreased （P<0.05）. Compared with model group， the LVEF and LVFS of the rats in ligustilide group were increased （P<0.05）， the LVESD and LVEDD were decreased （P<0.05），the percentage of myocardium infarction area was decreased （P<0.05）， and the expression levels of PKD1， HIF-1α，CD31， and VEGF mRNA and proteins in myocardium tissue were increased （P<0.05）； compared with model group，the LVEF and LVFS of the rats in CID group were decreased （P<0.05）， the LVESD and LVEDD were increased （P<0.05）， the percentage of myocardium infarction area was increased （P<0.05）， and the expression levels of PKD1， HIF-1α， CD31， and VEGF mRNA and proteins in myocardium tissue were decreased （P<0.05）； compared with ligustilide group， the LVEF and LVFS of the rats in ligustilide+CID group were decreased （P<0.05）， the LVESD and LVEDD were increased （P<0.05）， the percentage of myocardium infarction area was increased （P<0.05）， and the expression levels of PKD1， HIF-1α， CD31， and VEGF mRNA and proteins in myocardium tissue were decreased （P<0.05）；compared with CID group， the LVEF and LVFS of the rats in ligustilide+CID group were increased （P<0.05）， the LVESD and LVEDD were decreased （P<0.05）， the percentage of myocardium infarction area was decreased（P<0.05）， and the expression levels of PKD1， HIF-1α， CD31， and VEGF mRNA and proteins in myocardium tissue were increased （P<0.05）. Conclusion Ligustilide can promote the angiogenesis， reduce the myocardium infarction area， and improve the cardiac function in the rats with heart failure；it works through activation of the PKD1/HIF-1α/VEGF pathway.

Key words: Heart failure, Vascular regeneration, Ligustilide, Protein kinase D1, Hhypoxia induced factor-1α, Vascular endothelial growth factor