RESEARCH ARTICLE Topical Application of Oleuropein Induces Anagen Hair Growth in Telogen Mouse Skin

We observed that oleuropein, the main constituent of the leaves and unprocessed olive drupes ofOlea europaea, protected mice from high-fat diet-induced adiposity by up-regula-tion of genes involved in Wnt10b-mediated signaling in adipose tissue. The activation of Wnt/β-catenin pathway is also well established to positively regulate the anagen phase of hair growth cycle in mice skin. Methodology and Principal Findings Oleuropein promoted cultured human follicle dermal papilla cell proliferation and induced LEF1 and Cyc-D1 mRNA expression and β-catenin protein expression in dermal papilla cells. Nuclear accumulation of β-catenin in dermal papilla cells was observed after oleuro-pein treatment. Topical application of oleuropein (0.4 mg/mouse/day) to C57BL/6N mice ac-celerated the hair-growth induction and increased the size of hair follicles in telogenic mouse skin. The oleuropein-treated mouse skin showed substantial upregulation o