title: HPLC analysis of vitamin E isoforms in human epidermis: correlation with minimal erythema dose and free radical scavenging activity.
abstract: The content and composition of different vitamin E isoforms was analyzed in normal human skin. Interestingly the epidermis contained 1% alpha-tocotrienol, 3% gamma-tocotrienol, 87% alpha-tocopherol, and 9% gamma-tocopherol. Although the levels of tocotrienol in human epidermis appear to be considerably lower than reported in the hairless mouse, the presence of significant amounts of tocotrienol levels leads to speculation about the physiological function of tocotrienols in skin. Besides antioxidant activity and photoprotection, tocotrienols may have skin barrier and growth-modulating properties. A good correlation was found for epidermal alpha-tocopherol (r = 0.7909, p <.0003), gamma-tocopherol (r = 0.556, p <.025), and the total vitamin E content (r = 0.831, p <.0001) with the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging in epidermis, as assessed by electron paramagnetic resonance (EPR) spectroscopy. In human epidermis, alpha-tocopherol is quantitatively the most important vitamin E isoform present and comprises the bulk of first line free radical defense in the lipid compartment. Epidermal tocotrienol levels were not correlated with DPPH scavenging activity. The minimal erythema dose (MED), an individual measure for sun sensitivity and a crude indicator for skin cancer susceptibility, did not correlate with the epidermal content of the vitamin E isoforms. Hence it is concluded that vitamin E alone is not a determinant of individual photosensitivity in humans.
authors.affiliation: Department of Dermatology, Medical School, J.W. Goethe University, Frankfurt, Germany. jurgenfuchs@t-online.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Fuchs
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.forename: Maurizio
authors.initials: M
authors.lastname: Podda
authors.forename: Norbert
authors.initials: N
authors.lastname: Groth
authors.forename: Thomas
authors.initials: T
authors.lastname: Herrling
authors.forename: Lester
authors.initials: L
authors.lastname: Packer
authors.forename: Roland
authors.initials: R
authors.lastname: Kaufmann
mesh_terms: D002839:Chromans / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D004817:Epidermis / Q000737:chemistry*; D004890:Erythema / Q000378:metabolism*; D016166:Free Radical Scavengers / Q000378:metabolism*; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D007536:Isomerism; D008826:Microbial Sensitivity Tests; D024508:Tocotrienols; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry; D024502:alpha-Tocopherol / Q000032:analysis; D024504:gamma-Tocopherol / Q000032:analysis
chemical_list: D002839:Chromans; D016166:Free Radical Scavengers; D005609:Free Radicals; D024508:Tocotrienols; D014810:Vitamin E; C013649:plastochromanol 8; D024504:gamma-Tocopherol; C082032:tocotrienol, alpha; D024502:alpha-Tocopherol