In vitro effect of diammonium glycyrrhizinate on the growth of human hair follicles and Wnt/β-catenin signaling pathway

Abstract

Objective To evaluate the effect of diammonium glycyrrhizinate extracted from the Chinese traditional medicine licorice root on the growth of human hair follicles cultured in vitro, and to detect the expression of wnt/β-catenin signaling pathway-related molecules. Methods Isolated hair follicles were cultured with diammonium glycyrrhizinate at different concentrations of 0.1, 0.01, 0.001 and 0.000 1 μmol/L for 10 days, and the hair follicles cultured in Williams′ E medium without diammonium glycyrrhizinate served as a control group. The length of hair follicles was measured under a microscope every day, the morphologic changes of hair follicles were observed, and photos were taken. Immunofluorescence assay was performed to assess the proliferation of hair matrix cells, as well as to determine the expression of β-catenin, glycogen synthase kinase 3β (GSK3β) , phosphorylated GSK3β (p-GSK3β) and lymphoid enhancer factor-1 (Lef1) in the Wnt/β-catenin signaling pathway. Statistical analysis was carried out by repeated-measures analysis of variance and one-way analysis of variance. Results As repeated-measures analysis of variance showed, only 0.01 μmol/L diammonium glycyrrhetate showed significantly promotive effect on the growth of hair follicles compared with the medium alone (P 0.05) . Least significant difference (LSD) -t test revealed that the expre-ssion of β-catenin, p-GSK3β and Lef1 in the hair matrix cells was significantly higher in the 0.1-, 0.01-, 0.001-μmol/L diammonium glycyrrhizinate groups than in the control group (all P 0.05) . Conclusion Diammonium glycyrrhetate at the concentration of 0.01 μmol/L shows markedly promotive effect on the in vitro growth of hair follicles, and can increase the proliferative activity of hair matrix cells and delay the transition to the catagen phase, which may be associated with the activation of Wnt/β-catenin signaling pathway. Key words: Hair follicle; Organ culture techniques; Wnt signaling pathway; Fluoroimmunoassay; Diammonium glycyrrhizinate