Revisiting the Role of Melatonin in Human Melanocyte Physiology: A Skin Context Perspective

Melatonin, a hormone primarily known for its role in sleep regulation, also plays a significant role in human melanocyte physiology, which is responsible for skin and hair pigmentation. Melatonin and its metabolites inhibit melanogenesis (melanin production) and melanocyte proliferation, potentially through various signaling pathways. They also have antioxidant properties, protecting melanocytes from oxidative damage and maintaining mitochondrial homeostasis, which is crucial for skin health and aging. Topical melatonin significantly increased hair density and hair shaft diameter in men with androgenetic alopecia. However, the effects of melatonin are variable, depending on factors like dose and tissue type. The document emphasizes the need for further research, particularly ex vivo and in vivo studies, to clarify the role of melatonin in human melanocyte physiology and its potential therapeutic use in pigmentary disorders.