ESL attenuates BLM-induced IPF in mice: Dual mediation of the TLR4/NF-κB and TGF-β1/PI3K/Akt/FOXO3a pathways

• Published in: Phytomedicine (Stuttgart) 2024-09, Vol.132, p.155545, Article 155545
• Main Authors: Jia, Canchao, Yang, Minjuan, Xiao, Guanlin, Zeng, Zhihao, Li, Lingjie, Li, Yangxue, Jiang, Jieyi, Xu, Aili, Qiu, Jinyan, Tang, Ruiyin, Li, Dongmei, Jia, Dezheng, Xie, Canhui, Wu, Guangying, Cai, Dake, Bi, Xiaoli
• Format: Article
• Language: English
• Subjects: Animals; Anti-EMT process; Anti-inflammatory; Aqueous extract; Bleomycin; Disease Models, Animal; Drugs, Chinese Herbal - chemistry; Drugs, Chinese Herbal - pharmacology; Elephantopus scaber Linn; Epithelial-Mesenchymal Transition - drug effects; Forkhead Box Protein O3 - metabolism; Idiopathic pulmonary fibrosis (IPF); Idiopathic Pulmonary Fibrosis - chemically induced; Idiopathic Pulmonary Fibrosis - drug therapy; Immune mediate; Male; Mice; Mice, Inbred C57BL; Molecular Docking Simulation; Network Pharmacology; NF-kappa B - metabolism; Phosphatidylinositol 3-Kinases - metabolism; Proto-Oncogene Proteins c-akt - metabolism; Signal Transduction - drug effects; Toll-Like Receptor 4 - metabolism; Transforming Growth Factor beta1 - metabolism
• ISSN: 0944-7113; 1618-095X; 1618-095X
• DOI: 10.1016/j.phymed.2024.155545

Idiopathic pulmonary fibrosis (IPF) is a persistent and advanced pulmonary ailment. The roles of innate immunity and adaptive immunity are pivotal in the evolution of IPF. An ill-adjusted interaction between epithelial cells and immune cells is responsible for initiating the epithelial–mesenchymal transition (EMT) process and sustaining chronic inflammation, thereby fostering fibrosis progression. The intricacy of IPF pathogenesis has hindered the availability of efficacious agents. Elephantopus scaber Linn. (ESL) is a canonical Chinese medicine with significant immunoregulatory effects, and its aqueous extract has been proven to attenuate IPF symptoms in bleomycin (BLM)-induced mice. However, the underlying mechanism through which ESL relieves IPF remains unclear. To validate whether ESL reverses IPF by mediating the immune response and EMT. : Ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and UPLC were used to identify the components and determine the concentrations of the specific compounds in the ESL. Network pharmacology and molecular docking were applied to predict the potential mechanism underlying the anti-IPF effect of ESL. BLM-induced IPF mice were used to validate the anti-IPF effect of ESL, and lung tissue was collected to test putative pathways involved in inflammation and EMT via immunohistochemistry (ICH), real-time quantitative polymerase chain reaction (RT–qPCR) and Western blotting. Sixty-one compounds were identified, and thirteen main ingredients were quantified in the ESL. In silico experiments predicted that the IPF-mediated reversal of adverse effects by ESL would be related to interruption of the Toll-like receptor 4 (TLR4)/nuclear factor-k-gene binding (NF-ĸB) inflammatory pathway and the transforming growth factor-beta l (TGF-β1)/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/forkhead box O3 (FOXO3a) fibrosis pathway. In vivo experiments showed that ESL alleviates BLM-induced lung inflammation and fibrosis by reducing neutrophil aggregation and fibroblast foci, similar to the effects of the positive control drug pirfenidone (PFD). ESL markedly inhibited the transcription of TNF-α, IL-1β, and IL-6, which are downstream genes of the NF-κB signaling pathway. Furthermore, the protein levels of TLR4 and p-NF-κB were correspondingly inhibited in response to ESL treatment. Additionally, ESL reverses BLM-induced changes in the expression of EMT-related biological charac