Antifibrotic effects of lilii bulbus extract in a mouse model of bleomycin-induced pulmonary fibrosis

Objectives: Lilii Bulbus (LB), a lung-moistening herbal medicine, has been used to treat the symptoms of pulmonary fibrosis, including dry cough and dyspnea. In this study, we investigated whether LB water extract (LIB) has antifibrotic effects in a mouse model of bleomycin-induced pulmonary fibrosis. Materials and Methods: The effects of LIB and its mechanisms of action were investigated in a mouse model of bleomycin-induced (2 mg/kg, intratracheal) pulmonary fibrosis. LIB (30, 100, and 300 mg/kg) was administered orally twice daily for 10 days after induction. Changes in body weight, lung histology, inflammatory cells in bronchoalveolar lavage fluid (BALF), and the levels of transforming growth factor (TGF)-β, α-smooth muscle actin (α-SMA), and proinflammatory cytokines were evaluated. Results: LIB treatment decreased histological fibrotic change according to Ashcroft score, inflammatory cells, including total cells, macrophages, inflammatory cytokines (tumor necrosis factor-α and interleukin-6) in BALF, and TGF-β and α-SMA production in lung tissue. Conclusion: LIB exerted antifibrotic effects in a mouse model of bleomycin-induced pulmonary fibrosis by inhibiting inflammatory reactions and fibrotic mediators including TGF-β and α-SMA.