ELECTRON-PARAMAGNETIC-RESONANCE EVIDENCE OF THE GENERATION OF SUPEROXIDE (O-2(CENTER-DOT-)) AND HYDROXYL ((OH)-O-CENTER-DOT) RADICALS BY IRRADIATION OF A NEW PHOTODYNAMIC THERAPY PHOTOSENSITIZER, VICTORIA-BLUE-BO

Citation
A. Viola et al., ELECTRON-PARAMAGNETIC-RESONANCE EVIDENCE OF THE GENERATION OF SUPEROXIDE (O-2(CENTER-DOT-)) AND HYDROXYL ((OH)-O-CENTER-DOT) RADICALS BY IRRADIATION OF A NEW PHOTODYNAMIC THERAPY PHOTOSENSITIZER, VICTORIA-BLUE-BO, Journal of photochemistry and photobiology.B, Biology, 32(1-2), 1996, pp. 49-58
Citations number
48
Categorie Soggetti
Biophysics,Biology
ISSN journal
10111344
Volume
32
Issue
1-2
Year of publication
1996
Pages
49 - 58
Database
ISI
SICI code
1011-1344(1996)32:1-2<49:EEOTGO>2.0.ZU;2-P
Abstract
Electron paramagnetic resonance (EPR) experiments were performed on Vi ctoria Blue BO, a cationic dye whose photocytotoxicity has been studie d against the human leukaemic cell lines K-562 and TF-1. EPR experimen ts with 2,2,6,6-tetramethyl-4-piperidone and spin trapping with 5,5-di methyl-1-pyrroline-N-oxide showed that, on illumination in aerated aqu eous solution or DL-alpha-dipalmitoylphosphatidylcholine liposomes, ph otoexcited Victoria Blue BO is unable to generate O-1(2), whereas O-2( .-) and (OH)-O-. are trapped by 5,5-dimethyl-1-pyrroline-N-oxide in th e presence or absence of electron donors. The O-2(.-) formed probably leads to the (OH)-O-. radical, with an efficiency which is increased b y electron donors such as Fe2+.