Original Paper

Epidermal Ceramidase Activity Regulates Epidermal Desquamation via Stratum Corneum Acidification
E. Houben^a, J.P. Hachem^b, K. De Paepe^a, V. Rogiers<sup>a

a</sup>Department of Toxicology, Dermatocosmetology and Pharmacognosy, Vrije Universiteit Brussel, and
^bDepartment of Dermatology, Universitair Ziekenhuis Brussel, Brussels, Belgium

Address of Corresponding Author

Skin Pharmacol Physiol 2008;21:111-118 (DOI: 10.1159/000114872)

  Key Words

• Ceramidase
• Epidermis
• Desquamation
• pH

  Abstract

The acidic pH of the outer surface of the mammalian skin plays several important roles in the epidermal barrier function. The 2 endogenous pathways that are currently known to elicit this acidic pH are the generation of free fatty acids from phospholipids and the exchange of protons for sodium ions by non-energy-dependent sodium-proton exchangers. In this study, we propose a third endogenous pathway, i.e. epidermal ceramidase activity, generating free fatty acids from ceramides. By topical application of N-oleylethanolamine, a well-known ceramidase inhibitor, we could demonstrate a significant increase in the stratum corneum pH and a corresponding decrease in the epidermal free fatty acid content. Moreover, we could show that the resulting change in the apparent skin pH also provoked a delay in early barrier recovery and an increased epidermal desquamation, corresponding to earlier observations made for the already known endogenous mechanisms.

Copyright © 2008 S. Karger AG, Basel

  Author Contacts

E. Houben
Department of Toxicology, Dermatocosmetology and Pharmacognosy
Vrije Universiteit Brussel
Laarbeeklaan 103, BE-1090 Brussels (Belgium)
Tel. +32 2 477 45 96, Fax +32 2 477 45 82, E-Mail evi.houben@telenet.be

  Article Information

Received: August 21, 2007
Accepted: November 14, 2007
Published online: February 5, 2008
Number of Print Pages : 8
Number of Figures : 6, Number of Tables : 1, Number of References : 45