Nifuroxazide Ameliorates Pulmonary Fibrosis By Blocking Myofibroblast Genesis And Stat3 Activation: A Drug Repurposing Study
Abstract Background: Idiopathic pulmonary fibrosis (IPF) is a lung disease with complex pathogenesis, high mortality. The development of new drugs is time-consuming and laborious, and the research on new use of old drugs can save time and clinical costs and even avoid serious side effects. Nifuroxazide (NIF) was originally used to treat diarrhoea, but in recent years it has been found to have other pharmacological effects such as anti-tumor and inhibiting inflammatory diseases related to diabetic nephropathy. However, there are no reports about its role in pulmonary fibrosis.Methods: The therapeutic effect of NIF on bleomycin (BLM)-induced pulmonary fibrosis in vivo was measured by ELISA, hydroxyproline content, H&E and Masson staining, IHC and Western blot. The content of immune cells in lung tissue was analyzed by flow cytometry. NIF cytotoxicity were evaluated in NIH/3T3, Human pulmonary fibroblasts (HPF), A549 and Rat primary lung fibroblasts (RPLF) using MTT assay. Finally, a cell model induced by transforming growth factor-β1 (TGF-β1) stimulation and different in vitro experiments (Immunofluorescence, Western blot, Wound migration assay) were conducted to determine the effect of NIF on the activation of fibroblasts and the epithelial-mesenchymal transition (EMT) and migration of epithelial cells.Results: In vivo, intraperitoneal injection of NIF relieved and reversed pulmonary fibrosis caused by BLM bronchial instillation. In addition, nifuroxazide inhibited the expression of a variety of cellular inflammatory factors and immune cells. Furthermore, nifuroxazide suppressed the activation of fibroblasts and the EMT of epithelial cells induced by TGF-β1. Most importantly, we used an analytical docking experiment and thermal shift assay to further verify that nifuroxazide worked in conjunction with Stat3. Moreover, nifuroxazide decreased the expression of p-Stat3 in vitro and in vivo.Conclusion: These results suggest that NIF inhibits and reverses pulmonary fibrosis and support NIF as a viable treatment option that may bring benefits to patients with IPF.