Synergistic proliferating effects of electrical stimulation and minoxidil on human dermal papilla cells

Background: Previous published clinical studies have demonstrated the positive effects of electrical stimulation (ES) on hair growth. Minoxidil (MXD) enhances hair growth by prolonging the anagen phase of hair follicles. MXD is used to promote hair growth in androgenetic alopecia. Objective: To investigate the combined effect of ES and MXD on cultured human dermal papilla cells (hDPCs). Methods: hDPCs were electrically stimulated with different parameter settings of alternating current. Electrically stimulated hDPCs were incubated in an MXD medium, after which cell proliferation was measured using an MTT assay. Ki-67 and β-catenin expressions were measured by immunofluorescence assay. In addition, Wnt/β-catenin pathway-related gene expressions were measured by real time-PCR, and phosphorylated ERK and AKT protein levels were measured by western blot assay. Results: The combination of 8 V-1 MHz ES and MXD treatment promoted hDPC proliferation effectively, compared with that in the control, ES alone, or MXD alone treatment groups. The immunofluorescence assay showed that the expression of Ki-67 and β-catenin significantly increased in the combined treatment group. Most of the Wnt/β-catenin pathway-related gene expressions increased more with combined treatment than with the control, ES alone, or MXD alone treatments. However, there were no significant differences in the expression levels of phosphorylated ERK and AKT among the treatment groups. Conclusion: ES combined with MXD treatment had a synergistic effect on the proliferation of hDPCs. This might be through the synergistic activation of the Wnt/β-catenin pathway.