Dietary glucosylceramide is absorbed into the lymph and increases levels of epidermal sphingolipids

Abstract

The positive effects of dietary glucosylceramide (GlcCer) are well-known. In previous experiments, the efficacy was demonstrated in increasing skin moisture of human subjects [ [1] Asai S. Miyachi H. Evaluation of skin-moisturizing effects of oral or percutaneous use of plant ceramides. Rinsho Byori. 2007; 55: 209-215 PubMed Google Scholar ], in repairing disrupted skin barrier functions of mice [ [2] Tsuji K. Mitsutake S. Ishikawa J. Takagi Y. Akiyama M. Shimizu H. et al. Dietary glucosylceramide improves skin barrier function in hairless mice. J Dermatol Sci. 2006; 44: 101-107 Abstract Full Text Full Text PDF PubMed Scopus (89) Google Scholar ], and in relieving allergic skin symptoms of atopic patients [ 3 Kimata H. Improvement of atopic dermatitis and reduction of skin allergic responses by oral intake of konjac ceramide. Pediatr Dermatol. 2006; 23: 386-389 Crossref PubMed Scopus (30) Google Scholar , 4 Miyanishi K. Shiono N. Shirai H. Dombo M. Kimata H. Reduction of transepidermal water loss by oral intake of glucosylceramides in patients with atopic eczema. Allergy. 2005; 60: 1454-1455 Crossref PubMed Scopus (26) Google Scholar ], but the underlying mechanism is incompletely defined. Our study was performed (1) to confirm whether or not dietary GlcCer increases the epidermal ceramide (Cer) levels and (2) to identify Cer metabolites in thoracic lymph fluid in animal models. All procedures performed in this study were approved by the Ethical Committee of Kao Corporation and conform to the guidelines for the animal experimentation.