Synthesis and discovery of new compounds bearing coumarin scaffold for the treatment of pulmonary fibrosis.

Idiopathic pulmonary fibrosis, characterized by excess accumulation of extracellular matrix, involved in many chronic diseases or injuries, threatens human health greatly. We have reported a series of compounds bearing coumarin scaffold which potently inhibited TGF-β-induced total collagen accumulation in NRK-49F cell line and migration of macrophages. Compound 9d also suppressed the TGF-β-induced protein expression of COL1A1, α-SMA, and p-Smad3 in vitro. Meanwhile, 9d at a dose of 100 mg/kg/day through oral administrations for 4 weeks effectively alleviated infiltration of inflammatory cells in lung tissue and fibrotic degree in bleomycin-induced pulmonary fibrosis model, which may related to its inhibition of TGF-β/Smad3 pathway and anti-inflammation efficacy. In addition, 9d demonstrated decent bioavailability (F = 39.88%) and suitable eliminated half-life time (T1/2 = 13.09 h), suggesting that 9d could be a potential drug candidate for the treatment of fibrotic diseases.