Treatment With Cyclohexyl Salicylate, an Olfactory Receptor 2A4/7 Agonist, Promotes Human Hair Follicle Growth and Bulge Stem Cell Progeny Expansion

The study explored the effects of the olfactory receptor (OR) 2A4/7 agonist, cyclohexyl salicylate (CHS), on human hair growth. OR2A4/7 was found to be expressed in the hair follicle epithelium, specifically the outer root sheath (ORS) and hair matrix (HM). In scalp hair follicle organ culture, CHS delayed catagen (hair follicle regression phase) development and increased HM proliferation. While CHS did not seem to affect K15+ bulge stem cells, it significantly increased the percentage of CD34+ cells (immediate progeny of K15+ stem cells) in the suprabulbar ORS, as well as the percentage of CD71+ transit amplifying cells in the HM and suprabulbar ORS. These findings suggest that CHS promotes hair growth and expands the progeny of K15+ stem cells, making it a potential treatment for hair loss disorders characterized by premature catagen development and a reduced capacity of K15+ stem cells to generate progeny, such as androgenetic alopecia.