Effect of Lithocholic Acid as a Ligand of Vitamin D Receptor on Hair Growth in Alopecia

The study from May 2016 explored the effects of lithocholic acid (LCA), a vitamin D receptor (VDR) ligand, on hair growth in the context of alopecia. It was found that LCA treatment significantly increased the proliferation of human dermal papilla cells (hDPCs) and upregulated hair growth markers including VDR, RXRα, alkaline phosphatase, β-catenin, and dephospho-β-catenin in a dose-dependent manner. Additionally, LCA promoted hair shaft elongation and counteracted the inhibition of cell growth and reduction in alkaline phosphatase expression caused by hair degeneration mediators like IFN-γ or TNF-α. The study also showed that VDR knockout resulted in decreased cyclin D1 and increased p21 WAF1/CIP1 expression, which are key in cell cycle regulation. Conversely, LCA treatment boosted Bcl-2 and cyclin D1 expression while suppressing Bax and p21 WAF1/CIP1 expression in hDPC cells. These findings suggest that LCA, through VDR activation, could be important for hair regeneration in alopecia.