Pharmacokinetics Integrated With Network Pharmacology to Investigate the Potential Mechanism of Lu‐Jiao Fang Inhibited Endothelial‐to‐Mesenchymal Transition in Pressure Overload–Induced Cardiac Fibrosis

ABSTRACT The aim of this study was to investigate the potential mechanism of Lu‐Jiao Fang (LJF) inhibiting endothelial‐to‐mesenchymal transition (EndMT) in pressure overload‐induced cardiac fibrosis. Pharmacokinetic behaviors of the ingredients of LJF were evaluated by LC‐MS/MS analysis. Then putative pathways by which LJF regulates EndMT were analyzed by network pharmacology and verified in transverse aortic constriction–induced cardiac fibrosis rats. Loganin, morroniside, salidroside, isopsoralen, and psoralen showed higher plasma, left and right ventricular C max and AUC 0–t values than hesperidin, specnuezhenide, and icariside II. Twenty‐four potential targets related to EndMT were identified, which were mainly involved in relaxin signaling pathway. AKT1, TP53, MMP9, HIF1A, Snail1, and MMP2 were key therapeutic targets in protein–protein interaction network. LJF reversed cardiac dysfunction, left ventricular dilation, and fibrosis and significantly downregulated collagen type I and III and EndMT regulators (Snail1 and Twist1) mRNA expression. In relaxin signaling pathway, the RXFP1 protein expression increased by 22.52%, and the protein phosphorylation of Smad2 and Smad3 decreased by 33.52% and 12.79%, in response to the treatment with LJF. This study initially revealed the EndMT inhibition effects and molecular mechanisms of LJF in cardiac fibrosis, providing a reference basis for the promotion of LJF in the clinic.