Celastrol-Ligustrazine compound proven to be a novel drug candidate for idiopathic pulmonary fibrosis by intervening in the TGF-β1 mediated pathways-an experimental in vitro and vivo study.

Idiopathic Pulmonary Fibrosis (IPF) is a disease characterized by pulmonary interstitial fibrosis and collagen proliferation, currently lacking effective therapeutic options. The combined use of Celastrol and Ligustrazine has been proved to synergistically improve the pathological processes of inflammation and fibrosis. In earlier studies, we designed and synthesized a Celastrol-Ligustrazine compound CL-001, though its role in IPF remains unclear. Here, the effects and mechanisms of CL-001 in bleomycin (BLM)-induced IPF were investigated. In vivo, CL-001 significantly improved lung function, reduced pulmonary inflammation, and decreased collagen deposition, thereby preventing the progression of IPF. In vitro, CL-001 concurrently inhibited both Smad-dependent and Smad-independent pathways, thereby suppressing TGF-β1-induced epithelial-mesenchymal transition (EMT) and epithelial cell migration. This inhibitory effect was superior to that of Celastrol or Ligustrazine administered alone. Additionally, CL-001 significantly increased the level of apoptosis and promoted the expression of apoptosis-related proteins (Caspase-8 and PARP), ultimately leading to widespread apoptosis in activated lung epithelial cells. In summary, CL-001 exhibits excellent anti-IPF effects both in vitro and in vivo, suggesting its potential as a novel candidate drug for IPF, warranting further development.