The effect of vernonia anthelmintica flavone on melanogenesis of human melanocytes in vitro
MA Hui-jun1,ZI Shao-xia2,LI You1,LIU Wen1,WANG Yi-xia1,ZHAO Guang1 (1.Department of Dermatology,the Airforce General Hospital of Chinese PLA,Beijing 100036,China;2.Department of Dermatology and venerology,Xuanwu Hospital of Capital Medical University,Beijing 100053)
Objective To investigate the effect of vernonia anthelmintica flavone (VAF) on melanogenesis and tyrosinase activity of human epidermal melanocytes, and initially discuss their related mechanism. Methods Cell proliferation was observed by MTT method. Three different concentrations of VAF were incubated with human melanocytes for 72h and then melanin content, tyrosinase activity were respectively measured. The protein expression of melanogenesis key enzymes was investigated by western blot. Results The proliferation of melanocytes was most inhibited by VAF at high dose (≥100μg/ml). In the range of experimental dose, VAF increased the activity of the tyrosinase and melanin content significantly in a dose-dependent manner. The increasing protein expression of TRP1 was also observed in a dose-dependent manner. No effect was observed on protein expression of TYR and TRP2. Conclusion VAF may stimulate melanogenesis directly on human epidermal melanocytes, which may be induced by increasing expression of TPR1 and post-translational modification of TYR.