title: Comet assay combined with p53 detection as a sensitive approach for DNA photoprotection assessment in vitro.
abstract: A simple in vitro approach where sun formulations are spread on a quartz slide and placed over human skin cells in culture is proposed as a convenient test for photoprotection assessment at the DNA level. Using the comet assay, DNA strand breaks and oxidative DNA damage were detected. Then, accumulation of p53 protein was studied as a marker for UV-induced genotoxic stress. Such a method was used to compare formulations with different photostability. Spectroradiometry showed that a photo-unstable formulation lost its effectiveness in UVA screening when pre-irradiated by simulated sunlight. As a consequence, such a formulation was not as protective as a photostable one at the genomic level.
authors.affiliation: Genotoxicity Group, L'Oréal Research, 1 avenue E. Schueller, 96300 Aulnay-sous-Bois, France. lmarrot@recherche.loreal.com
authors.forename: Laurent
authors.initials: L
authors.lastname: Marrot
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Belaïdi
authors.forename: Jean-Roch
authors.initials: JR
authors.lastname: Meunier
mesh_terms: D002478:Cells, Cultured; D020552:Comet Assay; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D006801:Humans; D012867:Skin / Q000166:cytology; D012879:Skin Physiological Phenomena / Q000187:drug effects* / Q000528:radiation effects*; D013473:Sunscreening Agents / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D013473:Sunscreening Agents; D016159:Tumor Suppressor Protein p53; D004247:DNA