Phytoceramides
Phytosphingosine is a long-chain
sphingoid base that has important cellular functions such as signaling,
cytoskeletal structure, cellular cycle, and heat stress response. It is found
largely in mammals, plants, and yeast. Phytosphingosine has seen much use in
cosmetics due to its effects on the skin such as reducing inflammation by
inhibiting the expression of the
allergic cytokines IL-4 and TNF-α and
the activation of the transcription factors NF-jB and c-jun in
histamine-stimulated skin tissues.1 Phytosphingosine can lead to
apoptosis via two distinct pathways and has been investigated as a possible
cancer therapeutic treatment.2 Phytoceramides (fatty acids acylated to phytosphingosines) are distributed
at the microvillous membrane of the epithelial cells of the small intestine.
Crypt cells and the adjacent epithelial cells produce phytosphingoglycolipids
in much greater quantities than more differentiated epithelial cells.3
The kidney and skin contain phytosphingoglycolipids although in much lower
concentrations than in the small intestine. Phytoceramides also form part of
the water barrier lipids of the skin.
References:
- K. Ryu et al. “Anti-scratching Behavioral Effects of N-Stearoylphytosphingosine and 4-Hydroxysphinganine in Mice” Lipids, Vol. 45 pp. 615-618, 2010
- M. Park et al. “Suppression of Extracellular Signal-related Kinase and Activation of p38 MAPK Are Two Critical Events Leading to Caspase-8- and Mitochondria-mediated Cell Death in Phytosphingosine-treated Human Cancer Cells” Journal of Biological Chemistry, Vol. 278, pp. 50624-50634, 2003
- F. Omae et al. “DES2 protein is responsible for phytoceramide biosynthesis in the mouse small intestine” Journal of Biochemistry, vol. 379 pp. 687-695, 2004