title: Further investigations on the role of ascorbic acid in stratum corneum lipid models after UV exposure.
abstract: This study is the continuation of our research into vitamin C and its possible effects on human skin after topical administration. The effects of ascorbic acid, iron ions and UV irradiation on stratum corneum lipid models were investigated. The lipid models used were: a simple system (linolenic acid dispersion), a complex system (liposomes consisting of dipalmitoylphosphatidylcholine, cholesterol and linolenic acid) and complex systems with additionally incorporated ceramides (types III and IV). The lipid peroxidation was quantified by the thiobarbituric acid assay. A human adult low-calcium high-temperature (HaCaT) keratinocytes cell culture was used as a second in-vitro model. The amount of intracellular peroxides was determined by measuring the fluorescence intensity using the dihydrorhodamine 123 assay. Electron paramagnetic resonance spectroscopy was used to study the influence of ascorbic acid and iron ions on the signal intensity of 5-doxylstearic acid during UV exposure. Ascorbic acid showed prooxidative properties in the thiobarbituric acid assay whereas cell protection was measured in the HaCaT keratinocytes experiments. Electron paramagnetic resonance investigations revealed different extents of free radical production generated by iron ions, ascorbic acid and UV irradiation. In evaluating the results from this study new aspects of the mechanism of lipid damage caused by these three factors were suggested, transcending the simple redox behaviour of ascorbic acid.
authors.affiliation: Martin-Luther-University Halle-Wittenberg, School of Pharmacy, Institute of Pharmaceutics and Biopharmaceutics, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle (Saale), Germany. trommer@pharmazie.uni-halle.de
authors.forename: Hagen
authors.initials: H
authors.lastname: Trommer
authors.forename: Rolf
authors.initials: R
authors.lastname: Böttcher
authors.forename: Christoph
authors.initials: C
authors.lastname: Huschka
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wohlrab
authors.forename: Reinhard H H
authors.initials: RH
authors.lastname: Neubert
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology*; D002460:Cell Line; D002518:Ceramides / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D004578:Electron Spin Resonance Spectroscopy; D005296:Ferrous Compounds; D006801:Humans; D015603:Keratinocytes; D019787:Linoleic Acid / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D015227:Lipid Peroxidation; D008081:Liposomes; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012235:Rhodamines; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D002518:Ceramides; D005296:Ferrous Compounds; D008081:Liposomes; D008563:Membrane Lipids; D017382:Reactive Oxygen Species; D012235:Rhodamines; C058319:dihydrorhodamine 123; C020748:ferrous sulfate; D002784:Cholesterol; D019787:Linoleic Acid; D001205:Ascorbic Acid