Diammonium Glycyrrhizinate Alleviated Myocardial Fibrosis Induced by Isoprenaline Via Modulation of STAT/Smad3 Pathway

Myocardial fibrosis (MF) severely impairs the heart structure and function post-myocardial infarction. The study investigated the effectiveness and mechanism of diammonium glycyrrhizinate (DG) on ISO-induced MF. ISO-stimulated mouse cardiac fibroblasts (CFs) were treated with DG to assess the proliferation, inflammation, and fibrosis markers (α-SMA, collagen, TGF-β1, Smad3). The MF model was induced in mice by administering ISO, followed by a 4-week treatment with DG (60 mg/kg/day). Cardiac function was measured using echocardiography, and histology and molecular analyses were performed. DG significantly suppressed the CF proliferation and reduced the expression of fibrotic markers. In ISO-treated mice, DG improved the cardiac function and attenuated the upregulated fibrosis markers. Molecular analysis revealed DG suppressed the TGF-β1/Smad3 pathway activation. The antifibrotic effect was enhanced when combined with STAT3 inhibition. DG effectively alleviates ISO-induced myocardial fibrosis dysfunction by inhibiting the STAT3/Smad3 signaling pathway, demonstrating its potential as a treatment for cardiac fibrosis. Graphical abstract