Screening Of Anti-hypertrophic Scar Agents And The Mechanism Research

Objectives Hypertrophic scar(HPS)is characterized by excessive fibrosis associated with aberrant function of fibroblasts.Yet no satisfactory treatment has been developed.In this study,we screened anti-hypertrophic scar agents and investigate its underlying mechanisms.Methods We screened 903 natural small compounds for anti-hypertrophic scar agents via four steps and identified 5,7,4',5' contained flavonoids as novel agents for treatment of HPS.5,7,4',5' contained flavonoids were topical applicated(10 ?M dissolved in 100 ?L sterile saline plus 10% dimethyl sulfoxide)to mechanical load-induced scars in mice once a day for 14 days.Histology and immunohistochemistry study were performed to evaluate scar hypertrophy and the function of fibroblasts.Human hypertrophic scar-derived fibroblasts(HSFs)were determined by immunofluorescence study and collagen gel contraction assay.Also,protein expression of transforming growth factor signaling pathway was detected using Western blotting.Lastly,molecular docking study and kinase binding assay were conducted in search of the potential interaction between 5,7,4',5' contained flavonoids and activin receptor-like kinase 5(ALK5).Results These compounds treatment significantly attenuated HPS formation and collagen deposition in a mechanical load-induced mouse model.5,7,4',5' contained flavonoids also inhibited the proliferation and activation of fibroblasts in vitro and in vivo.Besides,5,7,4',5' contained flavonoids could impair the contractile ability of HSFs.Protein expression investigation revealed that these compounds had inhibitory effect on TGF-?/Smad2/3 signaling.Such bioactivity of 5,7,4',5' contained flavonoids may result from theirs selective binding to the ATP-binding pocket of ALK5 as suggested by molecular docking study and kinase binding assay.Conclusions 5,7,4',5' contained flavonoids could serve as promising agents for treatment of HPS and selective ALK5 inhibitors.