Qiliqiangxin capsule improves cardiac remodeling in rats with DOCA-salt-induced diastolic dysfunction.

The aim of this study was to investigate the protective effect and mechanism of action (MOA) of Qiliqiangxin capsule (QL) in the deoxycorticosterone acetate (DOCA) salt-induced rat heart failure with preserved ejection fraction (HFpEF) model.Nono-nephrectomy sixty Sprague Dawley (SD) rats received DOCA salt injection and 1% saline in drinking water for 4 weeks and were randomly divided into four groups on average: Model group (n=15), Sac/Val group (Sacubitril Valsartan 0.02 g/kg, n=15), QL-L group (Qiliqiangxin 0.25 g/kg, n=15) and QL-H group (Qiliqiangxin 1 g/kg, n=15). Another Normal group was set (n=15). Blood pressure, N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac index, echocardiography, and hemodynamics were measured to evaluate heart function. Masson and Wheat germ agglutinin (WGA) staining was performed to observe the fibrosis deposition and the cross-sectional area (CSA) of cardiomyocytes. The concentration levels of the serum cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-2, IL-6, and IL-10 inflammatory factors, were detected by ELISA; matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), transforming growth factor-β1 (TGF-β1), nuclear factor-κB (NF-κB), Smad homologue 2 (Smad2) and Smad homologue 3 (Smad3) expression were detected by Western-blot.Compared with the Model group, QL treatment significantly ameliorated the heart function in DOCA salt-induced rat HFpEF model, showing a decrease in cardiac index, an increase of the EF and E/A ratio, a reduction in the left ventricular anterior/posterior wall (LVAW/LVPW), in the time contraction of isovolumic diastolic time (IVRT), -dP/dt Max, and Tau, and the decrease of serum NT-ProBNP. Masson and WGA staining indicated that QL inhibited the fibrosis deposition and the myocardial hypertrophy compared with the Model group, which was consistent in reducing the protein expression levels of cardiac remodeling such as TGF-β1, MMP2, MMP9, Smad2, and Smad3. Moreover, QL treatment inhibited the expression of NF-κB in the heart tissues and decreased the serum concentration of pro-inflammatory cytokines TNF-α and IL-2, instead, increasing the IL-10 concentration.QL improved the cardiac function and inhibited the myocardial fibrosis in DOCA salt-induced rat HFpEF by improving diastolic dysfunction, preventing left ventricular hypertrophy, and ameliorating the inflammatory responses model in DOCA salt-induced rat HFpEF model.