Abstract
Septic cardiomyopathy (SCM) is manifested by impairment of cardiac contractile function with myocardial mitochondrial dysregulation. Natural product, songorine (SGR), a diterpenoid alkaloid derived from the lateral root of Aconitum carmichaeli, has been reported for the treatment of heart failure. Here, the protective role of SGR in heart injury of SCM was investigated and its underlying action of mechanism was explored. Firstly, the mouse and cardiomyocytes (H9C2 cell) SCM model induced by LPS were established to evaluate the therapeutic effect of SGR. The in vivo results exhibited that SGR rescued the survival rate of SCM mice, restored the loss of ejection fraction (EF) and fractional shortening (FS), and reduced left ventricular systolic diameter and left ventricular diastole diameter (LVIDs, LVIDd) by echocardiography. SGR improved the mitochondrial biosynthesis and myocardial fiber structure and arranged them neatly by transmission electron microscope (TEM). Further, SGR inhibited inflammatory targets myeloperoxidase (MPO) and tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and plasminogen activator inhibitor-1 (PAI-1). And SGR activated the mitochondrial biosynthesis-related peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), β-catenin, and matrix metallopeptidase 2 (MMP2) proteins. Meanwhile, the in vitro results showed that SGR promoted the increased the myocardial H9C2 cell viability, and mitochondrial biosynthesis and structure. SGR also blocked the inflammatory factors and reversed PGC-1α, β-catenin, and MMP2 in vitro, while SGR alleviated the myocardial cell apoptosis via flow cytometry. The findings indicate that SGR mitigates sepsis-caused myocardial damage by Wnt/β-catenin signaling pathway-mediated mitochondrial biosynthesis. SGR may be a promising candidate for treatment of SCM.