LAUSR

OBJECTIVE Many endogenous or exogenous factors, isolated or combined, can trigger dry skin disorder, leading to a water/lipids-depleted stratum corneum concomitant with uncomfortable rough and scaly skin surface. In a defensive reaction, the alteration of the skin barrier stimulates the production of cytokines to initiate homeostasis restoration but this can also induce an inflammatory response that further weakens the barrier. The two phenomena intertwining one another lead to the creation of a vicious circle, here called Inflamm'dryness, that maintains dry skin state. It is thus very important to investigate biological mechanisms involved in Inflamm'dryness to better manage dry skin. METHODS A 3D model mimicking dry skin has been developed. Adjustment of tape stripping level allowed to reproduce skin barrier alterations and resulting inflammation involved in dry skin. The effect of Helichrysum stoechas extract on this downward spiral was then investigated to validate the concept. RESULTS Tape-stripping permitted to successively remove the cell layers of the stratum corneum: the barrier function was altered and skin was inflamed creating a vicious circle, mimicking very dry skin prone to Inflamm'Dryness. Helichrysum stoechas extract was not only able to resolve inflammation but also to reverse concurrently adverse tape stripping effects and imparted significant structural and functional recovery of the barrier (e.g. on NMF and ceramides levels, TEWL, tissue organization). CONCLUSION This 3D model reproduces Inflamm'Dryness vicious circle present in dry skin and highlights the importance of breaking this process to improve dry skin conditions. Helichrysum stoechas extract is a promising active ingredient for the management of dry skin.