149 Dermo-cosmetic formulations containing Rhealba® oat sap improve fragile skin barrier function and protect against pollution

Abstract

The skin provides a major interface between the body and the environment and offers a biological barrier against air pollutants. Recent epidemiological studies suggest that pollutants negatively affect human skin and exacerbates preexistent skin diseases. Fragile skins show impairment of the epithelial barrier function with a lower resistance to aggressions. The aim of this study was to evaluate the efficacy of formulations, containing Rhealba® oat sap, to provide a “shield effect” against pollution and reinforce fragile skin barrier function. The “shield effect” was evaluated on skin explants, by the quantification of a radiolabeled outdoor pollutants (B(a)P and Urban Dust PM10) mix penetration. Reconstructed human epidermis (RHE) were treated with SDS then formulations were topically applied before an outdoor pollutant stress to mimic fragile skin exposed to environmental pollution. The out-in barrier function was quantified by measuring the penetration of the fluorescent dye Lucifer Yellow (LY) through the stratum corneum (SC) and SC lipid synthesis was quantified by HTPLC/UV. After application of the formulations, the penetration of pollutants through the skin is reduced significantly up to 50%, demonstrating their “shield effect”. Treatment of RHE with the rich cream showed a significant inhibition of LY penetration into the SC by 67% vs stressed control, indicating a fragile skin barrier function strengthening. Moreover, we observed the decrease of the pollutant penetration in this model. Finally, formulation dedicated to xerosis increased specific ceramide synthesis up to 50% for esterified ceramides. In conclusion, dermo- cosmetic formulations, containing Rhealba® oat sap, present a “shield effect” against pollution and reinforce skin barrier function.