Fig. 4. Luteolin, quercetin or myricetin suppresses the activation and contractile behavior of dermal fibroblast.

Representative images and quantitative analysis of fibrosing tissues from in vivo models (a bleomycin-induced model; b mechanical load-induced model) stained for α-SMA show significant suppression induced by luteolin, quercetin or myricetin on fibroblast activation. c Immunofluorescence staining for α-SMA and F-actin in cultured human dermal fibroblasts (HDFs) after incubation with TGF-β1 (5 ng/ml) and DMSO or drugs for 48 or 72 h. α-SMA is shown by red fluorescence and F-actin by green fluorescence. d Representative images and quantitative results of collagen gel contraction assay show that luteolin, quercetin or myricetin significantly inhibited HDF-mediated gel contraction with exogenous TGF-β1 (5 ng/ml) treatment. Data are the mean ± SD (three independent experiments); **P < 0.01, ***P < 0.001