The use of suction blisters to measure sunscreen protection against UVR-induced DNA damage.

Abstract

The formation of DNA photoproducts caused by solar UVR exposure needs to be investigated in-vivo and in particular in order to assess sunscreens' level of protection against solar genotoxicity. The study's purposes were: i) to evaluate if the roof of suction blisters is an appropriate sampling method for measuring photoproducts, and ii) to measure in-vivo sunscreen protection against cyclobutane pyrimidine dimers. Skin areas on the interior forearms of eight healthy volunteers were exposed in-vivo to 2 MED of simulated solar radiation (SSR) and to 15 MED on a sunscreen protected area. After irradiation, six suction blisters were induced and the blister roofs were collected. Analysis of SSR-induced CPDs was performed by two independent methods: a chromatography coupled to mass spectroscopy (HPLC-MS/MS) approach and a 3D-imaging of CPD immunostaining by multiphoton microscopy on floating epidermal sheets. HPLC-MS/MS analyses showed that SSR-unexposed skin presented no CPD dimers, whereas 2 MED SSR-exposed skin showed a significant number of TT-CPD. The sunscreen covered skin exposed to 15 MED appeared highly protected from DNA damage, as the amount of CPD-dimers remained below the detection limit. The multiphoton-immunostaining analysis consistently showed that no CPD staining was observed on the non-SSR-exposed skin. A significant increase of CPD staining intensity and number of CPD-positive cells were observed on the 2 MED SSR-exposed skin. Sunscreen protected skin presented a very low staining intensity and the number of CPD-positive cells remained very close to non-SSR-exposed skin. This study showed that suction blister samples are very appropriate for measuring CPD dimers in-vivo, and that sunscreens provide high protection against UVR-induced DNA damage.

• Authors: Gwendal Josse, Thierry Douki, Jimmy Le Digabel, Eleonore Gravier, Emmanuel Questel
• Journal: Journal of photochemistry and photobiology. B, Biology (J Photochem Photobiol B) Vol. 179 Pg. 1-6 (Feb 2018) ISSN: 1873-2682 [Electronic] Switzerland
• PMID: 29289926 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical References

• Pyrimidine Dimers
• Sunscreening Agents

Topics

• Adult
• Blister (genetics, metabolism, pathology)
• Chromatography, High Pressure Liquid
• DNA Damage (drug effects, radiation effects)
• Female
• Humans
• Male
• Pyrimidine Dimers (analysis)
• Skin (drug effects, radiation effects)
• Sun Protection Factor
• Sunscreening Agents (pharmacology)
• Tandem Mass Spectrometry
• Ultraviolet Rays
• Young Adult