title: Study of compounds suppressing free radical generation from UV-exposed ketoprofen.
abstract: Ketoprofen [(RS)-2-(3-benzoylphenyl)propanoic acid] is widely used for the treatment of inflammatory diseases and musculoskeletal injury. However, there is concern regarding its potential for photosensitization as a side effect. Free radicals and active oxygen species generated from ketoprofen on exposure to ultraviolet (UV) light have been implicated in phototoxicity and photosensitization. In this study, we examined the suppressing ability of some compounds for the free radicals and active oxygen species generated by the photodynamic reaction of ketoprofen, to determine a new resist of photosensitization by ketoprofen. Eight compounds, including six known free radical scavengers were individually mixed with ketoprofen, and the mixtures were exposed to UV. Then, the free radicals and the active oxygen species were determined by the electron spin resonance spectrometry to estimate suppressing and scavenging ability of compounds. The compounds that show promise in suppressing superoxide anion generation from UV-exposed ketoprofen were further evaluated using the on-line photo-irradiated superoxide anion detection system. It was confirmed that quercetin, a flavonoid, strongly suppresses the generation of free radicals and active oxygen species from UV-exposed ketoprofen. The experiments using the experimental formulation of an adhesive skin patch of ketoprofen containing quercetine and the Chemiluminescence analyzer (CLA) indicated that quercetin has high potential for use as an excipient in ketoprofen ointments to suppress phototoxicity and photosensitization by ketoprofen.
authors.affiliation: Department of Analytical Chemistry, Hoshi University, Tokyo, Japan. nakajimaa@nissanchem.co.jp
authors.forename: Ayako
authors.initials: A
authors.lastname: Nakajima
authors.forename: Maiko
authors.initials: M
authors.lastname: Tahara
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakazawa
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D004817:Epidermis / Q000528:radiation effects*; D016166:Free Radical Scavengers / Q000378:metabolism; D005609:Free Radicals / Q000032:analysis* / Q000378:metabolism; D007660:Ketoprofen / Q000494:pharmacology*; D010545:Peroxides / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016166:Free Radical Scavengers; D005609:Free Radicals; D010545:Peroxides; D017382:Reactive Oxygen Species; D007660:Ketoprofen