Anti-androgenetic alopecia effect of policosanol from Chinese wax by regulating abnormal hormone levels to suppress premature hair follicle entry into the regression phase.

Previously, we have demonstrated that policosanol from Chinese wax suppressed testosterone(T)-induced alopecia in mice. However, the underlying mechanism remained to be determined. Herein, we investigated the mechanism of policosanol against androgenetic alopecia (AGA). AGA was induced in Kunming mice by subcutaneous administration of testosterone propionate for 60 d. Policosanol (0.5 %, 1% or 2%) was applied topically on the back of mice. Finasteride (2%) was applied topically as a positive control. The serum T and estradiol (E2) concentrations were determined by ELISA after 28 and 60 days of treatment. The cutaneous expression or activity of key mediators of hair growth, such as alkaline phosphatase (ALP), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF), was measured. MTS assay was performed to evaluate cell proliferation in cultured human dermal papilla cells (DPCs) treated with dihydrotestosterone (DHT). Western blotting was performed to evaluate the protein expression of Bax, Bcl2, TGF-ß2, caspase-9, and caspase-3. We found lower T and T/E2 ratio in mice treated with policosanol than in the model group. Policosanol suppressed premature hair follicle entry into the regression phase, as shown by improving VEGF and EGF expression and ALP activity. The MTS assay showed that policosanol markedly inhibited the apoptosis of DHT-treated DPCs. Western blotting showed that policosanol significantly reduced the protein expression of TGF-ß2, cleaved caspese-9, cleaved caspase-3, and Bax, and increased that of Bcl2. The optimal effect was obtained with 12.50 g/mL policosanol. In conclusion, policosanol prevents androgenetic alopecia by regulating hormone levels and suppressing premature hair follicle entry into the regression phase.

Hair growth promoting effect of white wax and policosanol from white wax on the mouse model of testosterone-induced hair loss.

White wax (WW) has been traditionally used to treat hair loss in China. However there has been no reporter WW and its extract responsible for hair growth-promoting effect on androgenetic alopecia. In this paper, we examined the hair growth-promoting effects of WW and policosanol of white wax (WWP) on model animal of androgenetic alopecia and the potential target cell of WW and WWP. WW (1, 10 and 20%) and WWP (0.5, 1 and 2%) were applied topically to the backs of mice. Finasteride (2%) was applied topically as a positive control. MTS assays were performed to evaluate cell proliferation in culture human follicle dermal papilla cells (HFDPCs). The inhibition of WW and WWP for 5α- reductase were tested in Vitro. Results showed more lost hairs were clearly seen in mice treated with TP only and TP plus vehicle. Mice which received TP plus WW and WWP showed less hair loss. WW and WWP showed an outstanding hair growth-promoting activity as reflected by the follicular length, follicular density, A/T ratio, and hair bulb diameter. The optimal treatment effect was observed at 10% WW and 1% WWP, which were better than 2% finasteride treatment. MTS assay results suggested that WW and WWP remarkably increased the proliferation of HFDPCs. Inhibitor assay of 5α- reductase showed that WW and WWP inhibited significantly the conversion of testosterone to dihydrotesterone, and the IC50 values of WW and WWP were higher than that of finasteride. In Conclusion, WW and WWP could act against testosterone-induced alopecia in mice, and they promoted hair growth by inhibiting 5α-reductase activity and HFDPCs proliferation. DPCs is the target cell of WW and WWP.