Human placental extract exerts hair growth-promoting effects through the GSK-3β signaling pathway in human dermal papilla cells

Human placental extract (HPE) is widely used in Korea to relieve fatigue. However, its effects on human dermal papilla cells (hDPCs) remain unknown. In the present study, in an effort to develop novel therapies to promote hair growth, we screened HPE. We demonstrate that HPE has hair growth-promoting activities and induces β-catenin expression through the inhibition of glycogen synthase kinase-3β (GSK-3β) by phosphorylation in hDPCs. Treatment with HPE significantly increased the viability of the hDPCs in a concentration-dependent manner, as shown by bromodeoxyuridine (BrdU) assay. HPE also significantly increased the alkaline phosphatase (ALP) expression levels. The increased β-catenin levels and the inhibition of GSK-3β (Ser9) by phosphorylation suggested that HPE promoted the hair-inductive capacity of hDPCs. We compared the effects of treatment with HPE alone and treatment with HPE in conjunction with minoxidil (MXD). We found that HPE plus MXD effectively inhibited GSK-3β by phosphorylation (Ser9) in the hDPCs. Moreover, we demonstrated that HPE was effective in inducing root hair elongation in rat vibrissa hair follicles, and that treatment with HPE led to a delay in catagen progression. Overall, our findings suggest that HPE promotes hair growth and may thus provide the basis of a novel therapeutic strategy for the clinical treatment of hair loss.