629 The third brain: When skins well-being struggles against stressful lifestyles

Abstract

We previously showed that topical application of hexoses such as fructose accelerates stratum corneum barrier recovery after barrier disruption. We also showed that various hexoses and polyols interact with phospholipids and decrease the phase transition temperature from the liquid crystal to the crystal phase; i.e., they stabilize the fluid phase of lipids at low temperature. In the present study, we confirmed that topical application of xylitol aqueous solution on human skin after tape stripping accelerated barrier recovery. We next examined changes of lipid fluidity in an epidermal-equivalent model after the application of water and aqueous solutions of xylitol and fructose. For this purpose, we used Laurdan, an environmentally sensitive fluorescence dye, as an indicator of lipid fluidity and observed its emission spectrum with a two-photon microscope. Application of xylitol and/or fructose aqueous solution increased the lipid fluidity of the stratum granulosum layer compared to water application. These results indicate that topical application of certain hexoses or polyols increases the lipid fluidity at the uppermost layer of the stratum granulosum, accelerates the release of lipid from the stratum granular layer, and improves epidermal barrier homeostasis. 627Fluctuation of Caspase 14 caused by temperature and humidity unbalances the NMF production pathway and the process of keratinocyte enucleation