Modulation in NF-κB-p65/NLRP3, TXNIP-mediated signaling using an ethanolic fruit extract of Withania coagulans mitigates silica-induced pulmonary fibrosis in rats

Withania coagulans encompasses many active phytoconstituents, which have been used to treat many ailments. Prior research has shown that fruit extract of Withania coagulans has anti-inflammatory properties and effectively reduces oxidative stress in various diseases. Nevertheless, its effects are not obscured in the silica (SiO₂) induced pulmonary fibrosis (PF). In the current study, an ethanolic fruit extract of Withania coagulans (WCE) was prepared, and its effects and underlying mechanisms on SiO₂-induced PF in rats were elucidated. LC-MS/MS analysis identified various bioactive phytoconstituents, secondary plant metabolites, and flavonoids in the WCE. In vitro, results showed that the WCE exhibited no toxicity towards A549 cells, reduced the production of reactive oxygen species, and inhibited cell migration. Further, WCE abrogated alveolar wall thickening, reduced inflammatory cell infiltration, and maintained lung architecture. It also suppresses collagen accumulation and mucus production, abrogating inflammation by downregulating nuclear factor kappa B (NF-κB-p65)/ NOD-like receptor protein 3 (NLRP3) and cytokine levels. It suppresses oxidative and endoplasmic reticulum stress induced by SiO₂ by downregulating thioredoxin-interacting protein (TXNIP), activating transcription factor 6 (ATF6), and C/EBP Homologous Protein (CHOP) proteins. Additionally, WCE, by suppressing EMT and transforming growth factor beta 1 (TGF-β1)/Suppressor of Mothers against Decapentaplegic (Smad) pathway, mitigated PF in rats. Taken together, WCE via anti-inflammatory and anti-oxidative properties inhibited SiO₂-induced PF, and therefore, it can be envisaged as an effective antifibrotic agent to treat PF.