Abstract:

Objective  To explore the inhibitory effect of curcumin on the growth of human skin fibroblast (HSF) and possible mechanisms. Methods  HSF were cultured in vitro and treated with different concentrations of curcumin for different time periods. The viability of HSF was detected by MTT, changes of cell cycle were detected by flow cytometry; and mRNA and protein expressions of transforming growth factor-β (TGF-β1), Smad3, and Smad7 were detected by RT-PCR and Western blotting. Results  The viability of HSF treated with curcumin of 40 μmol/L obviously decreased (P<0.001). The curcumin of 40 μmol/L significantly decreased the number of cells in the S phase but increased the number of cells in the G1 phase (P<0.001). Furthermore, mRNA and protein expressions of TGF-β1 and its downstream factor Smad3 were significantly inhibited, while mRNA and protein expressions of Smad7 significantly increased in a concentration dependent manner (P<0.001). Conclusion  Curcumin inhibits the signaling pathway of TGF-β1 and further inhibits the proliferation of HSF by up-regulating the protein expression of Smad7 and down-regulating the protein expression of Smad3, which provides new ideas for clinically improving the wound healing.

Key words: curcumin, transforming growth factor-β1, Smad3, Smad7, skin fibroblast