C18 Phytoceramide (t18:0 18:0) (Cer(t18:0 18:0)) is a bioactive sphingolipid found in S. cerevisiae, wheat grains, and the stratum corneum layer of mammalian epidermis. Cer(t18:0 18:0) is composed of a phytosphingosine backbone amine-linked to a C18 fatty acid chain. Cer(t18:0 18:0) has a role in regulation of apoptosis, cell differentiation, proliferation of smooth muscle cells, and inhibition of the mitochondrial respiratory chain. It also inhibits expression of the allergic cytokines IL-4, TNF-α, and transcription factors c-Jun and NF-κB in histone-stimulated murine skin tissue. Formulations containing cer(t18:0 18:0) have been used used in cosmetics as a skin protectants as they reduce water loss to prevent epidermal dehydration and irritation.
C2 Phytoceramide is a bioactive semisynthetic sphingolipid that inhibits formyl peptide-induced oxidant release (IC50 = 0.38 μM) in suspended polymorphonuclear cells. It increases COX-2 protein levels 15-fold through ERK signaling. It induces death of keratinocytes (20% viability) with an ED50 value of 30 μM, the same concentration at which 35% of cells in a TUNEL assay are apoptotic. C2 Phytoceramide also has antiproliferative effects in CHO cells, with greater than 80% cytotoxicity achieved at a concentration of 20 μM, and induces internucleosomal DNA fragmentation. In addition, it inhibits the activation of phospholipase D (PLD) mediated by muscarinic acetylcholine receptors in vitro.
C16 Phytoceramide (t18:0/16:0) is a phytoceramide, which is a family of sphingolipids found in the intestine, kidney, and extracellular spaces of the stratum corneum of the mammalian epidermis. C16 Phytoceramide (t18:0/16:0) is composed of a phytosphingosine backbone amine-linked to a C16 fatty acid chain. The levels of C16 phytoceramide (t18:0/16:0) increase following heat stress in S. cerevisiae. It has been used with other ceramides to create stratum corneum substitutes to study percutaneous penetration and psoriasis in vitro.
C24 Phytosphingosine (t18:0/24:0) is a phytoceramide, which is a family of sphingolipids found in the intestine, kidney, and extracellular spaces of the stratum corneum of the mammalian epidermis. C24 Phytosphingosine (t18:0/24:0) is composed of a phytosphingosine backbone amine-linked to a C24 fatty acid chain. It has been used with other ceramides to create stratum corneum substitutes to study percutaneous penetration and psoriasis in vitro. In a stratum corneum model of healthy skin, the incorporation of long-chain-containing phytoceramides, such as C24 phytosphingosine (t18:0/24:0), increases permeability of the membrane in comparison with incorporation of dihydroceramides.