title: The effect of camphorquinone (CQ) and CQ-related photosensitizers on the generation of reactive oxygen species and the production of oxidative DNA damage.
abstract: Recent evidence suggests that following visible-light (VL) irradiation, CQ and the CQ-related photosensitizers benzil (BZ), benzophenone (BP), and 9-fluorenone (9-F) generate initiating radicals that may indiscriminately react with molecular oxygen forming reactive oxygen species (ROS). The purpose of this investigation was to determine whether VL-irradiated CQ, BZ, BP, and 9-F cause DNA damage due to the generation of ROS in vitro. ROS formation by CQ and CQ-related photosensitizers+/-dimethyl-p-toluidine (DMT) was investigated in a cell-free system with VL irradiation. DNA damage was determined using PhiX-174 RF I supercoiled double-stranded plasmid DNA and ROS quantified with 4-((9-acridinecarbonyl)amino)-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO-9-AC), a fluorogenic ROS-sensitive probe. VL-irradiated CQ, BZ, BP, and 9-F (+/-DMT) produced significant DNA damage at 0.1, 0.5, and 1.0 mM and in a concentration-dependent manner (p<0.05). TEMPO-9-AC revealed that all investigated VL-irradiated photosensitizers produced significant amounts of ROS with BZ in the presence of DMT generating the most ROS after 30, 60, and 90 min. VL-irradiated CQ, BZ, BP, and 9-F +/-DMT continued to generate significant amounts of ROS 90 min after VL irradiation. As a result, future investigations should evaluate the effect of VL-irradiated photosensitizers in cells and possible protective effects provided by antioxidants.
authors.affiliation: Department of Restorative Dentistry, University of Washington, D-770, Health Science Building, Box 357456, Seattle, WA 98195-7456, USA.
authors.forename: Dustin
authors.initials: D
authors.lastname: Pagoria
authors.forename: Abert
authors.initials: A
authors.lastname: Lee
authors.forename: Werner
authors.initials: W
authors.lastname: Geurtsen
mesh_terms: D001577:Benzophenones / Q000737:chemistry* / Q000528:radiation effects; D001672:Biocompatible Materials / Q000737:chemistry / Q000528:radiation effects; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D004249:DNA Damage; D005449:Fluorenes / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D008422:Materials Testing; D010084:Oxidation-Reduction; D010658:Phenylglyoxal / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000528:radiation effects; D017319:Photosensitizing Agents / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000138:chemical synthesis*; D013729:Terpenes / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D001577:Benzophenones; D001672:Biocompatible Materials; D005449:Fluorenes; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D013729:Terpenes; C048339:camphoroquinone; C047723:benzophenone; D004247:DNA; C028401:9-fluorenone; D010658:Phenylglyoxal; C006697:benzil