The effect of N-acetyl-glucosamine on stratum corneum desquamation and water content in human skin

J. Cosmet. Sci., 60, 423–428 (July/August 2009) Synopsis Alpha-hydroxy acids have been used topically to treat skin for both dermatological and cosmetic problems for many years. Though there are many known benefits of the use of α-hydroxy acids on skin, there have been recent reports that topical treatments with α-hydroxy acids increase skin damage resulting from UVB. Additionally, high concentrations of α-hydroxy acids by themselves have also been found to cause skin irritation. In order to find alternatives to α-hydroxy acids, we investigated a variety of amino sugar compounds that were previously reported to inhibit the reaggregation of dissociated corneocytes by modulating cellular adhesion. In vivo, we observed that topical treatments with a formulation containing N-acetyl-glucosamine (NAG) led to an increase in skin moisturization, a decrease in skin flakiness, and the normalization of stratum corneum exfoliation. In vitro, we observed an upregulation of differentiation markers, keratin 10 and involucrin, in keratinocytes treated with NAG. CD44 is a lectin cell adhesion molecule that is also expressed in keratinocytes. Amino sugars such as NAG may competitively bind to CD44, modulating keratinocyte cellular adhesion. We hypothesize that these amino sugars modulate keratinocyte cellular adhesion and differentiation, leading to the normalization of stratum corneum exfoliation. We propose the use of amino sugars such as NAG as alternative compounds to replace the use of α-hydroxy acids in skin care.