Hair growth‐promoting effects of Camellia seed cake extract in human dermal papilla cells and C57BL/6 mice

Camellia seed cake is a by-product of Camellia oleifera Abel seed after oil extraction. Washing hair with Camellia seed cake extract is a traditional Chinese custom that has lasted for over one thousand years. However, the hair growth-promoting effects of Camellia seed cake extract were not investigated so far. This work examined the effects of de-saponinated Camellia seed cake extracts (DS-CSE) on hair growth, using in vitro and in vivo models.The studies on cell proliferation, cell cycle regulation, and K+ channels activation effects of DS-CSE were performed on human dermal papilla cells (DPCs). Relative expression of insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and transforming growth factor-β (TGF-β1) in DPCs was determined by RT-PCR. Relative expression of ERK and AKT was determined by Western blot analysis. Hair growth-promoting effects were also measured in C57BL/6J mice model.DS-CSE treatment significantly proliferated DPCs, relating to the increased proportion of DPCs in S and G2 /M phases, the activation of potassium channels and the promoted phosphorylation of ERK and AKT in DPCs. DS-CSE treatment also significantly upregulated the mRNA levels of HGF, VEGF and IGF-1, and downregulated the mRNA level of TGF-β1. Topical application of DS-CSE promoted hair growth on shaven back mice and also upregulated the expression of VEGF in mice.Our results demonstrated that DS-CSE exerts a hair growth-promoting effect in vitro and in vivo by proliferating DPCs through the ERK and AKT signaling pathways and regulating the expression of growth factors.