title: DNA dosimetry assessment for sunscreen genotoxic photoprotection.
abstract: BACKGROUND
  Due to the increase of solar ultraviolet radiation (UV) incidence over the last few decades, the use of sunscreen has been widely adopted for skin protection. However, considering the high efficiency of sunlight-induced DNA lesions, it is critical to improve upon the current approaches that are used to evaluate protection factors. An alternative approach to evaluate the photoprotection provided by sunscreens against daily UV radiation-induced DNA damage is provided by the systematic use of a DNA dosimeter.
  
  
  RESULTS
  The Sun Protection Factor for DNA (DNA-SPF) is calculated by using specific DNA repair enzymes, and it is defined as the capacity for inhibiting the generation of cyclobutane pyrimidine dimers (CPD) and oxidised DNA bases compared with unprotected control samples. Five different commercial brands of sunscreen were initially evaluated, and further studies extended the analysis to include 17 other products representing various formulations and Sun Protection Factors (SPF). Overall, all of the commercial brands of SPF 30 sunscreens provided sufficient protection against simulated sunlight genotoxicity. In addition, this DNA biosensor was useful for rapidly screening the biological protection properties of the various sunscreen formulations.
  
  
  CONCLUSIONS
  The application of the DNA dosimeter is demonstrated as an alternative, complementary, and reliable method for the quantification of sunscreen photoprotection at the level of DNA damage.
authors: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors: André Passaglia
authors: AP
authors: Schuch
authors: Juliana Carvalhães
authors: JC
authors: Lago
authors: Teiti
authors: T
authors: Yagura
authors: Carlos Frederico Martins
authors: CF
authors: Menck
mesh_terms: D000704:Analysis of Variance; D004247:DNA / Q000378:metabolism*; D004249:DNA Damage; D006801:Humans; D009153:Mutagens / Q000633:toxicity*; D011874:Radiometry; D059405:Sun Protection Factor; D013472:Sunlight; D013473:Sunscreening Agents / Q000494:pharmacology*
chemical_list: D009153:Mutagens; D013473:Sunscreening Agents; D004247:DNA