Wogonin inhibits transforming growth factor β1-induced extracellular matrix production via the p38/activator protein 1 signaling pathway in nasal polyp-derived fibroblasts.

BACKGROUND: Wogonin has been shown to have antifibrotic and anti-inflammatory effects in the lower airway. The purpose of this study was to evaluate the effects of wogonin on transforming growth factor (TGF) β1-induced myofibroblast differentiation, extracellular matrix production, migration, and collagen contraction, and to determine the molecular mechanisms of wogonin in nasal polyp-derived fibroblasts (NPDF).

METHODS: NPDFs were isolated from nasal polyps from eight patients. TGF-β1-induced NPDFs were treated with wogonin. Cytotoxicity was evaluated by using a 3-(4,5- dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide assay. Fibroblast migration was evaluated with transwell and scratch migration assays. The expression levels of α-smooth muscle actin, fibronectin, phosphorylated-p38, and c-Fos were determined by Western blot and/or reverse transcription-polymerase chain reaction. The total collagen amount was analyzed with the Sircol collagen assay, and contractile activity was measured by a collagen gel contraction assay.

RESULTS: Wogonin (0-60 μM) had no significant cytotoxic effects on TGF-β1-induced NPDFs. Migration of NPDFs was significantly inhibited by wogonin treatment. The expression levels of α-smooth muscle actin and fibronectin were significantly reduced in wogonin-treated NPDFs. Collagen production and contraction were also significantly decreased by wogonin treatment. Wogonin markedly inhibited activation of the p38/activator protein 1 pathway in TGF-β1-induced NPDFs.

CONCLUSION: These results indicated that wogonin may inhibit TGF-β1-induced myofibroblast differentiation, extracellular matrix production, migration, and collagen contraction through the p38/activator protein-1 pathway in NPDFs.