Ganoderma leucocontextum ethanol extract alleviates silica-induced pulmonary injury via TGF-β1/RUNX3/SMADs pathway

Ganoderma leucocontextum, a distinctive fungal species native to the Qinghai-Tibet Plateau, has been incorporated into the Tibetan pharmacopoeia for medicinal applications targeting inflammation reduction and lung protection. However, its therapeutic potential and underlying mechanisms against silicosis remain largely unexplored.

To explore the therapeutic capabilities of Ganoderma leucocontextum ethanol extract (GLE) in treating silicosis and uncover its molecular mechanisms.

Ultra-performance liquid chromatography Q-Exactive mass spectrometry (UPLC-QE-MS) was employed to identified the main components of GLE. The experimental silicosis model was established through intratracheal silica administration, with subsequent daily treatment using GLE via gastric gavage. Pathological evaluation was assessed through hematoxylin-eosin (H&E), Masson's trichrome staining and immunohistochemistry (IHC) staining. Inflammatory cytokines (TNF-α, TGF-β1, IL-1β, IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Integrated transcriptomics and network pharmacology analyses identified pivotal regulatory pathways. TGF-β1-induced lung epithelia (BEAS-2B) and fibroblasts (NIH/3T3 and HPF) were used to investigate GLE's effects on epithelial-mesenchymal transition (EMT), cell migration, extracellular matrix (ECM) deposition in vitro. Integrated qRT-PCR, western blotting and IHC were utilized to validate molecular mechanism.

UPLC-QE-MS identified 76 compounds in GLE, 36 of which exhibited potential bioactive properties. GLE significantly attenuated silica-induced pulmonary injury, suppressing inflammatory cytokines (TNF-α, TGF-β1, IL1β and IL-6) and collagen deposition. Multi-omics integration revealed that the TGF-β1/RUNX3/SMADs pathway serves as a key mechanism underlying the therapeutic efficacy of GLE in silicosis. Molecular analyses confirmed that GLE alleviates silica-induced pulmonary injury by inhibiting TGF-β1/RUNX3/SMADs signaling, suppressing ECM deposition and EMT. In vitro experiments demonstrated that GLE effectively alleviated TGF-β1-induced epithelial-mesenchymal transition. Furthermore, GLE suppressed fibroblast activation, as evidenced by inhibited cell migration and ECM deposition, through targeting the TGF-β1/RUNX3/SMADs pathway.

GLE mitigates silica-induced pulmonary injury by suppressing TGF-β1/RUNX3/SMADs pathway, highlighting its potential as a candidate for silicosis treatment.