[article]
| Titre : |
detection and identification of free radicals generated by UV and visible light in ex vivo human skin |
| Type de document : |
texte imprimé |
| Auteurs : |
Leonhard Zastrow, Auteur ; Norbert Groth, Auteur ; Frank Klein, Auteur ; Dieter Kockott, Auteur ; Jürgen Lademann, Auteur ; Louis Ferrero, Auteur |
| Année de publication : |
2008 |
| Article en page(s) : |
p. 207-215 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Peau
Peau -- Effet du rayonnement ultraviolet
Peau -- Effets du rayonnement solaire
Radicaux libres (chimie)
Rayonnement ultraviolet -- Effets physiologiques
Résonance paramagnétique électronique
Simulation, Méthode de
|
| Index. décimale : |
668.5 Parfums et cosmétiques |
| Résumé : |
Contrary to the skin biological end points used for determination of the sun protection factor and UVA protection factor, generation of excess free radicals in skin mainly reactive oxygen species is potentially the source of much skin damage and soo represents a more general biophysical answer to the effects of sun exposure of different wavelengths. By applying electron spin resonance spectroscopy to human skin biopsies, we determined in previous work a free radical action spectrum covering the ultraviolet and visible light range. Convolution of the action spectrum with sunlight spectral irradiance (280nm-700nm) showed the importance of visible light in free radical generation. This unexpected finding led us to perform further investigations. Firstly, an existing sun simulator was modified so that its outputtruly mimics the sun's full spectrum, including visible light. Human skin biopsies were irradiated either by this device or a conventional UV source, confirming our previous calculations : half of the free radicals are generated in the 400-700nm visible wavelength range.
Secondly, the visible spectrum of the modified sun simulator was divided into narrow-band lights using different pairs of short and long pass-filters. Human skin biopsies impregnated with specific spin traps were exposed to the different narrow-band lights in order to identify different types of free radicals. Generation of dangerous radical species like O2, OH and CH-R was observed in different parts of the visible range, confirming the relevance of the free racial action spectrum and its ability to predict skin protection. |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3807 |
in IFSCC MAGAZINE > Vol. 11, N° 3 (07-08/2008) . - p. 207-215
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detection and identification of free radicals generated by UV and visible light in ex vivo human skin in IFSCC MAGAZINE, Vol. 11, N° 3 (07-08/2008)
