Effect of a Simple Sugar-based Ingredient on Skin Moisturization: Biological Mode of Action and Clinical Effects

Purpose: The study aimed to investigate the effects of a sugar-based structure, i.e. XAX (Xylitylglucoside-Anhydroxylitol-Xylitol) on skin barrier function and moisturization, both in vitro and in vivo, and to compare its efficacy with that of glycerin.Methods: Expression of genes was investigated by RT-qPCR analysis on topically-treated human reconstructed epidermis. Ceramide neosynthesis was measured by chromatography in topically-treated human skin explants. Production of essential proteins was monitored in primary cell cultures: Chondroitin sulfate and hyaluronic acid in fibroblasts, using chromatography; hyaluronic acid in keratinocytes, using ELISA. In vivo, epidermal microrelief, skin capacitance and transepidermal water loss (TEWL) were measured on 25 female volunteers with dry skin. Skin capacitance and TEWL were also measured, on hands, comparing hydroalcoholic gels.Results: XAX increased the expression of key moisturizing-related genes, such as enzymes, structural components or regulators of inter-keratinocytes junctions, cornified layer, desquamation process, as well as skin barrier function and hydration. It also increased the contents of ceramides, hyaluronic acid and chondroitin sulfate. In vivo, XAX treatment at 3% decreased TEWL and increased skin capacitance, skin microrelief and desquamation. The combination of XAX+glycerin (1.5%+1.5%) showed interesting effects compared to glycerin alone.Conclusion: XAX promoted effects on the biological pathways involved in skin barrier function; epidermal and dermal water reserves; and epidermal water circulation. Its effectiveness, confirmed in vivo, alone and in combination with glycerin, makes it an interesting alternative to basic emollients, humectants and occlusives.