Comparison of in-vitro anti-fibrotic effects of pirfenidone and nintedanib

Abstract

Background: Idiopathic pulmonary fibrosis is incurable and has no effective treatment. The marketed drugs are only pirfenidone and nintedanib. By evaluating the inhibition effects of pirfenidone and nintedanib on the proliferation, migration and activation of human lung fibroblasts (HFL1), the anti-fibrotic mechanism of two drugs was tested and compared to provide reference for accurate clinical medication. Methods: HFL1 cells were divided into control group, TGF-β1/ PDGF-stimulate-model group, and drug-add group. The effect of pirfenidone and nintedanib on the proliferation and migration of HFL1 were evaluated by MTT assay and scratch test, respectively. Anti-pulmonary fibrosis effects of pirfenidone and nintedanib were evaluated by detecting the inhibitory activity of each drug on the expression of fibroblasts activation markers. The inhibitory effects of pirfenidone and nintedanib on TGF-β/Smad3 signaling pathway were evaluated by Western Blotting. Results: The results of MTT assays showed that both pirfenidone and nintedanib could inhibit TGF-β-induced proliferation of fibroblasts. In addition, both pirfenidone and nintedanib inhibited the migration of HFL1; Both pirfenidone and nintedanib can inhibit the expression of fibroblast activation markers, and they can inhibit the activation of TGF-β/Smad3 protein signaling pathway by inhibiting the phosphorylation of Smad3. The inhibition rate of Smad3 phosphorylation by nintedanib was 51%, and the inhibition rate of pirfenidone on Smad3 phosphorylation was 13%. Conclusion: Both pirfenidone and nintedanib could inhibit the proliferation, migration and activation of myofibroblasts, And all of them can exert anti-pulmonary fibrosis through TGF-β signaling pathway.