Curcumin Induced Decreased Expression of Type I Collagen in Human Skin Fibroblast Through Down-regulation of Smad2/3 Expressions / 대한피부과학회지

ABSTRACT

BACKGROUND: Imbalance among TGF-beta/Smad pathway, MMP-1, and TIMP-1 expressions results in sclerotic skin disease, such as scleroderma, hypertrophic scar, and keloids. Curcumin, a phytochemical extracted from the rhizomes of Curcuma longa, showed an anti-fibrotic effect in an animal study, such as a pulmonary and cholangioductal fibrosis animal model. However, the expressions of type I collagen, MMP-1, Smad2/3, and TIMP-1 in curcumin treated human skin fibroblasts is largely unknown. OBJECTIVE: The purpose of this study was to investigate the expressions of type I collagen, MMP-1, Smad2/3, and TIMP-1 proteins in curcumin-treated human skin fibroblasts. METHODS: Human skin fibroblasts were treated by various concentrations of curcumin (1~40 uM). The expressions of type I collagen, MMP-1, Smad2/3, and TIMP-1 proteins were analyzed by Western blot analysis. In addition, activities of type I collagen promoter were analyzed by the CAT assay. RESULTS: The expression of type I collagen decreased but the expression of MMP-1 and TIMP-1 increased by curcumin treatment in a dose and time dependent manner in Western blot analysis. Type I collagen promoter activities were decreased by curcumin treatment in the CAT assay. Smad2/3 expression decreased by curcumin treatment but TGF-beta1 induced Smad2/3 activation was not decreased by curcumin treatment following Western blot analysis. CONCLUSION: Decrease of type I collagen expression through the inhibition of Smad2/3 and increase of the expression of MMP-1, which is the degradating enzyme of type I collagen, in human skin fibroblasts by curcumin treatment offer expectation of curcumin as antifibrotic agent.