Atractylenolide-III restrains cardiac fibrosis after myocardial infarction via suppression of the RhoA/ROCK1 and ERK1/2 pathway

[Display omitted] •Atractylenolide-III improves cardiac function and reduces ischemia-induced oxidative stress and inflammation.•Atractylenolide-III inhibits TGF-β-induced fibroblast proliferation and collagen I synthesis in vitro.•It modulates RhoA/ROCK1/MRTF-A and ERK1/2 signaling pathways to reduce fibrosis.•Atractylenolide-III plays a key role in anti-fibrotic processes after myocardial infarction. Cardiac fibrosis, a critical factor in myocardial remodeling post-myocardial infarction (MI), can advance heart failure progression. Atractylenolide III (ATL-III), derived from Atractylodes lancea, has recognized antioxidant and anti-inflammatory effects; however, its influence on cardiac fibrosis remains unclear. MI was induced in mice by permanent ligation of the left anterior descending (LAD) coronary artery, followed by 2 weeks of ATL-III or dimethyl sulfoxide (DMSO) treatment. Cardiac fibrosis was assessed by echocardiography, tissue histology, and serum biomarkers of myocardial injury. In vitro, the effects of ATL-III on cardiac fibroblast (CF) proliferation and collagen deposition were evaluated using immunofluorescence, 5-Ethynyl-2′-deoxyuridine (EdU), and western blot techniques. Network pharmacology and molecular docking identified potential ATL-III targets. ATL-III treatment significantly improved cardiac function, as evidenced by increased ejection fraction (EF) and fractional shortening (FS) and reduced left ventricular dilation. Histological analysis revealed decreased fibrotic areas in ATL-III-treated mice, along with reduced expression of fibrosis markers α-SMA and Collagen I. ATL-III also alleviated oxidative stress by reducing reactive oxygen species (ROS) and malondialdehyde (MDA) levels while increasing superoxide dismutase (SOD) activity. Furthermore, ATL-III suppressed inflammation, decreasing TNF-α, IL-6, and IL-1β protein and mRNA levels. In vitro, ATL-III inhibited TGF-β1-induced CF proliferation, migration, and differentiation, reducing the expression of fibrotic markers. Mechanistically, ATL-III suppressed the RhoA/ROCK1 and ERK1/2 signaling pathways, as confirmed by molecular docking and pathway analysis. ATL-III demonstrates therapeutic potential in mitigating post-MI cardiac fibrosis by reducing oxidative stress, inflammation, and CF activation. These findings highlight ATL-III as a promising candidate for the treatment of cardiac fibrosis and associated heart failure.