Physalis Calyx seu Fructus inhibited pulmonary fibrosis through regulating Wnt/β-catenin signaling pathway

Pulmonary fibrosis is a chronic and advancing interstitial lung disease, and there is an urgent need for novel agents for its therapy. Physalis Calyx seu Fructus (PCF) has been utilized in traditional Chinese medicine to treat respiratory disorders with a long history, however, the therapeutic effect and mechanism of PCF against pulmonary fibrosis are still unclear. To assess therapeutic efficacy and underlying mechanism of 75% ethanol extract of PCF (PCF-EtOH) against pulmonary fibrosis, as well as to discover active constituents in PCF. A bleomycin-stimulated mice model was established to assess potential therapy of PCF-EtOH against pulmonary fibrosis in vivo. A lipopolysaccharide-induced inflammatory model in RAW 264.7 cells and a transforming growth factor β1-induced fibrosis model in MRC-5 cells were established to assess potential therapy and mechanisms of purified constituents in PCF-EtOH. UPLC-MS/MS analysis was adopted to ascertain the constituents of PCF-EtOH. Network pharmacology was employed to forecast targets of PCF against pulmonary fibrosis. PCF-EtOH ameliorated bleomycin-induced pulmonary fibrosis through repressing inflammatory response and extracellular matrix deposition. Meanwhile, PCF-EtOH inhibited Wnt/β-catenin pathway through decreasing β-catenin nuclear accumulation and promoting phosphorylation. Furthermore, withanolides and flavonoids were presumed to be main active compounds of PCF against pulmonary fibrosis based on the network pharmacology. Importantly, we found an extensive presence of withanolides in PCF-EtOH. Physapubescin, a typical withanolide in PCF-EtOH, inhibited the inflammatory response, extracellular matrix deposition, and Wnt/β-catenin pathway. Notably, physapubescin demonstrated a more potent antifibrotic effect than pirfenidone, a clinically approved antifibrotic drug, in the tested model. Withanolides and flavonoids are responsible for the inhibitory effect of PCF-EtOH against pulmonary fibrosis. Withanolides may represent a class of promising therapeutic agents against pulmonary fibrosis, and an in-depth exploration is warranted to validate this proposition.