Researcher Kanagawa Institute of Industrial Science and Technology Kawasaki, Kanagawa, Japan
Abstract: Oxytocin (OXT) is a neuropeptide hormone termed “love hormone” produced and released during childbirth and lactation. It is also produced in response to skin stimulation (e.g., during hugging and massaging), music therapy, and interaction with pet dogs. The effects of OXT on various organs; however, its specific effects on hair follicles remain unclear. Therefore, in this study, we aimed to investigate the hair growth-promoting effects of OXT. Dermal papilla cells control hair growth by providing growth/regression signals to the hair follicles. Gene expression analysis revealed that OXT significantly upregulated expression levels of hair growth-promoting factors, including vascular endothelial growth factor A, in dermal papilla cells. Hair growth-promoting effects of OXT were further tested using an in vitro drug screening model. Recently, we developed a hair follicle organoid (HFO) culture system where hair follicles regenerate efficiently in vitro (approximately 100%; T. Kageyama et al. Science Advances, 8, 42, eadd4603, 2022). Hair growth-promoting drug minoxidil increased the hair peg-like sprout length in HFOs (T. Kageyama et al. Scientific Reports, 13, 4847, 2023). Here, OXT also promoted the hair peg-like sprout growth in HFOs (T. Kageyama et al. Scientific Reports, 13, 15587, 2023). As OXT is an oligopeptide and a relatively large molecule (Mw = 1007), smaller molecular weight alternatives are needed to activate the OXT pathway via topical administration to the skin. Therefore, we examined the effects of OXT receptor activators and agonists as OXT alternatives on hair growth. Cinnamic acid (OXT receptor activator) and LIT001 (OXT receptor agonist) promoted hair sprout elongation in HFOs (T. Kageyama et al. Scientific Reports, 14, 4709, 2024 and T. Kageyama et al. Scientific Reports, 14, 23935, 2024). Collectively, our promising results can be beneficial for the development of novel hair growth products focused on OXT signaling.
