Flavones hydroxylated at 5, 7, 3′ and 4′ ameliorate skin fibrosis via inhibiting activin receptor-like kinase 5 kinase activity

Flavones with no less than four hydroxyls induce significant inhibition on Col1a2 and Col3a1 expression compared with vehicle in a 109 candidate flavones and b 39 positive compounds. c The frequency of hydroxy substitutions in 39 positive compounds. d The effectiveness of flavones with different hydroxy substitutions in 39 positive compounds. Flavones containing 5, 7, 3′, 4′ hydroxy substitution exhibits significantly stronger inhibition on collagen expression compared with flavones with other structures in e 109 candidate flavones and f 39 positive compounds. Data are the mean？±？SD (three independent experiments); **P？<？0.01, ***P？<？0.00