Abstract: Objective To evaluate the effects of （-）-epigallocatechin-3-gallate （EGCG） on the growth of human hair follicles and proliferation of cultured human dermal papilla cells （DPCs） in vitro. Methods Isolated hair follicles were cultured in 0.5 ml Williams Medium E with EGCG at 10 different concentrations （0, 0.01, 0.1, 1, 10,15.6, 31.25, 62.5, 125, 250 mg/L）. The growth of hair follicles was observed and recorded on day 1 and 10 during the culture. Human DPCs were isolated by two-step method from hair follicles, and cultured with various concentrations （0 - 500 mg/L） of EGCG. After 48 hours of culture, MTT assay was used to detect the proliferating rates of cultured DPCs, flow cytometry to analyze the cell cycle. Results Compard with the untreated controls, the growth of human hair follicles EGCG was stimulated at the concentrations of 0.1 and 1 mg/L （P < 0.05）, and the proliferation of cultured human DPCs was accelerated by the treatment with EGCG at the concentrations from 15.6 to 62.5 mg/L（P < 0.05）. An increase of cell proportion in S, G2 /M phases and decrease in G1 phase were observed in DPCs treated with EGCG at the concen- trations between 7.8 and 62.5 mg/L （P < 0.05）. Proliferation index of DPCs was increased from 5.25％ to 5.64％, 14.61％, 32.51％, 37.35％ by EGCG of 7.8, 15.6, 31.2 and 62.5 mg/L, respectively; and the increasing effect was positively correlated with the concentration of EGCG （r = 0.933）. Conclusion EGCG of given concentrations can accelerate the growth of human hair follicles and proliferation of cultured human DPCs.

Key words: human hair follicles, human dermal papilla cells(DPCs), EGCG, cell proliferation, cell cycle