Melatonin-Mediated Circadian Rhythm Signaling Exhibits Bidirectional Regulatory Effects on the State of Hair Follicle Stem Cells

The study explores the bidirectional regulatory effects of melatonin on hair follicle stem cells (HFSCs) in rats, mediated through the Rorα and Foxc1 genes. Melatonin downregulates Rorα, affecting Foxc1 expression, which is crucial for HFSC viability. Low doses of melatonin enhance HFSC viability and promote hair follicle reconstruction, while high doses inhibit it, preserving the stem cell pool. This suggests melatonin's circadian signaling could be a therapeutic target for hair loss conditions like alopecia. The study highlights the potential of melatonin in hair regeneration by modulating pathways such as Wnt/β-catenin, although further research is needed to understand the molecular mechanisms involved.