Topical tacrolimus suppresses the expression of vascular endothelial growth factor and insulin-like growth factor-1 in late anagen

Tacrolimus has shown promising results in the treatment of various dermatological diseases, including hair loss. The direct effect of tacrolimus on hair follicles and its underlying mechanisms have rarely been investigated. In this study, we investigated the effects of topical tacrolimus on anagen in the hair cycle and on the expression of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) mRNAs in mouse skin. Topical tacrolimus 0.1% ointment was applied to one side of the skin of depilated C57BL/6 mice. Skin samples from both sides were taken during the study. Vegf and Igf-1 mRNA were determined by quantitative RT-PCR. No obvious difference in skin colour, hair cycling or histological features was found between the treated and untreated skin, but the levels of Vegf mRNA and Igf-1 mRNA were markedly decreased in the treated skin in late anagen, compared with those in untreated skin.