SANDRINE DELAUNOIS¹, AMANDINE WERLE¹, BENOIT MIGNARD¹, CAROLINE MAKERRI¹, MARIA CELIA HIBARI REIMBERG², DANIEL SABARA², HANANE CHAJRA¹, MATHILDE FRECHET¹*
*Corresponding author
1. Clariant Active Ingredients, Toulouse, France
2. Beraca, São Paulo, Brazil

Abstract

This scientific paper aims to demonstrate that a new active ingredient ethically and sustainably sourced from a co-product of Brazil nut oil extraction, the Brazil Nut Press Cake Extract (BNPCE) restores the barrier function of compromised skins. Indeed, we demonstrated through transcriptomic and proteomic studies that this cosmetic active ingredient significantly upregulates genes with major functions in the maintenance of stratum corneum cohesion and quality (lipid synthesis and transport, and keratinocytes’ differentiation into corneocytes) and in the maintenance of the epidermis structure and cohesion. By acting on the three main levels responsible for skin barrier function, it efficiently improves skin hydration levels and reduces signs of redness in volunteers presenting signs of compromised skin, as demonstrated through two clinical studies.

INTRODUCTION

Our skin is our primary protection against the aggressors present in our environment, such as allergens, pathogens, irritants, UVs or chemicals. It creates a protective shield called skin barrier that prevents these aggressors from entering into our body. In addition, it prevents our body from losing its water, keeping moisture locked inside. This barrier is composed of three levels that each play a fundamental role. First, the lipid matrix that contributes to hold corneocytes together in the stratum corneum, just like mortar with bricks. The main lipids that compose it are long chain ceramides, free fatty acids and cholesterol, arranged in a lamellar structure that creates a continuous protective structure (1). Then, the corneocytes have an important role in regulating water flux and retention inside the skin as they are rich in natural moisturizing factor (NMF), originating mainly from keratin and the breakdown of filaggrin. Their cornified cell envelope is highly hydrophobic in mature corneocytes and was shown to be crucial for a proper barrier function (2). The renewal of the lipids and corneocytes in the stratum corneum is important in ...