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Contribution of oxidation reactions to photo-induced damage to cellular DNA.
- Source :
-
Photochemistry and photobiology [Photochem Photobiol] 2024 Sep-Oct; Vol. 100 (5), pp. 1157-1185. Date of Electronic Publication: 2024 Jul 05. - Publication Year :
- 2024
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Abstract
- This review article is aimed at providing updated information on the contribution of immediate and delayed oxidative reactions to the photo-induced damage to cellular DNA/skin under exposure to UVB/UVA radiations and visible light. Low-intensity UVC and UVB radiations that operate predominantly through direct excitation of the nucleobases are very poor oxidizing agents giving rise to very low amounts of 8-oxo-7,8-dihydroguanine and DNA strand breaks with respect to the overwhelming bipyrimidine dimeric photoproducts. The importance of these two classes of oxidatively generated damage to DNA significantly increases together with a smaller contribution of oxidized pyrimidine bases upon UVA irradiation. This is rationalized in terms of sensitized photooxidation reactions predominantly mediated by singlet oxygen together with a small contribution of hydroxyl radical that appear to also be implicated in the photodynamic effects of the blue light component of visible light. Chemiexcitation-mediated formation of "dark" cyclobutane pyrimidine dimers in UVA-irradiated melanocytes is a recent major discovery that implicates in the initial stage, a delayed generation of reactive oxygen and nitrogen species giving rise to triplet excited carbonyl intermediate and possibly singlet oxygen. High-intensity UVC nanosecond laser radiation constitutes a suitable source of light to generate pyrimidine and purine radical cations in cellular DNA via efficient biphotonic ionization.<br /> (© 2024 American Society for Photobiology.)
Details
- Language :
- English
- ISSN :
- 1751-1097
- Volume :
- 100
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Photochemistry and photobiology
- Publication Type :
- Academic Journal
- Accession number :
- 38970297
- Full Text :
- https://doi.org/10.1111/php.13990