Synergistic effect of rice bran extract and extremely low‐frequency electromagnetic fields on dermal papilla/melanocytes in melanogenesis

Melanocytes in hair are located around dermal papilla cells at the tip of the hair follicle. In this study, we examined the melanogenesis of a three‐dimensional (3D) hair dermal papilla model treated with natural extracts and electromagnetic fields (EMFs). The 3D model involved dermal papilla‐like tissue (DPLT), an aggregation of a mixture of dermal papilla cells, and melanocytes in microwells. Rice bran extract (RBE), an EMF, and RBE/EMF were applied to different DPLT groups. The LDH assay indicated no cell stress in all experimental groups, and detection of tyrosinase activity demonstrated high activity in the RBE/EMF group. Western blot analysis of the RBE, EMF, and RBE/EMF groups revealed increased MITF, TRP‐1, and tyrosinase expression. In addition, the mRNA expression of ET‐1, laminin, bFGF, β‐catenin, MITF, and tyrosinase was increased in the RBE/EMF group, as demonstrated by RT‐qPCR analysis. HMB45 and Fontana–Masson immunostaining showed that the RBE/EMF group had the highest melanin content. Therefore, RBE and EMF may be used as a material and therapy, respectively, for the treatment of vitiligo and white hair, through activation of melanogenesis in melanocytes. Bioelectromagnetics. 39:595–603, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc..