Many neuroleptics (phenothiazines) and antidepressant drugs are known to induce skin photosensitization after exposure to sunlight. Of them, three phenothiazines (perphenazine, thioridazine and fluphenazine) and three antidepressant drugs (fluvoxamine, amitriptiline and imipramine) were considered in terms of phototoxicity and photostability properties. A panel of ‘in vitro’ tests have been performed in order to assess their phototoxicity. They included: light absorption properties, reactive oxygen species generation, mouse erythrocyte hemolysis, linoleic acid peroxidation, isolated membrane protein cross-link, plasmid DNA cleavage and cell viability, under UVA (365 nm) irradiation. With the aid of various quenchers and scavengers the different species involved (free radicals, superoxide anion or singlet oxygen) were investigated. Phenothiazines have demonstrated the highest photosensitizing potential ‘in vitro’, mainly acting by Type I mechanism (radical generation). Photochemical degradation (in aqueous solution) under UVA light has also been studied. The main photoproducts have been isolated by HPLC and characterized by NMR and mass spectrometry. Preirradiated solutions of phenothiazines were able to hemolyze RBC in the dark, thus showing that photoproducts play a role in phototoxicity.

Photostability and photosensitizing properties of some CNS drugs

MIOLO, GIORGIA
;
VEDALDI, DANIELA ESTER;CAFFIERI, SERGIO;Viola G;DALL'ACQUA, FRANCESCO
1999

Abstract

Many neuroleptics (phenothiazines) and antidepressant drugs are known to induce skin photosensitization after exposure to sunlight. Of them, three phenothiazines (perphenazine, thioridazine and fluphenazine) and three antidepressant drugs (fluvoxamine, amitriptiline and imipramine) were considered in terms of phototoxicity and photostability properties. A panel of ‘in vitro’ tests have been performed in order to assess their phototoxicity. They included: light absorption properties, reactive oxygen species generation, mouse erythrocyte hemolysis, linoleic acid peroxidation, isolated membrane protein cross-link, plasmid DNA cleavage and cell viability, under UVA (365 nm) irradiation. With the aid of various quenchers and scavengers the different species involved (free radicals, superoxide anion or singlet oxygen) were investigated. Phenothiazines have demonstrated the highest photosensitizing potential ‘in vitro’, mainly acting by Type I mechanism (radical generation). Photochemical degradation (in aqueous solution) under UVA light has also been studied. The main photoproducts have been isolated by HPLC and characterized by NMR and mass spectrometry. Preirradiated solutions of phenothiazines were able to hemolyze RBC in the dark, thus showing that photoproducts play a role in phototoxicity.
1999
Book of Abstracts of the AMER SOC PHOTOBIOLOGY
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2501216
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