PHOTOSENSITIZING ACTION OF NONSTEROIDAL ANTIINFLAMMATORY DRUGS ON CELL-MEMBRANES AND DESIGN OF PROTECTIVE SYSTEMS

The pathways of photoreactivity of some nonsteroidal antiinflammatory drugs (NSAID), i.e. propionic acid derivatives indicated in a clinical picture as phototoxic and/or photoallergic, are discussed in a genera l oversimplified scheme. The NSAID photosensitizing activity, estimate d from the ability to induce red blood cell lysis, was found to be dep endent on the quantum yield of decarboxylation, which in turn determin es the superoxide anion formation, on free radical reactivity and 6n s inglet oxygen production efficiency. An investigation into the NSAID p hotoinduced cell damage in erythrocytes from various mammalian species , erythrocyte ghosts and unilamellar liposomes, evidenced the role pla yed by membrane proteins and phospholipids. To inhibit phototoxic effe cts, some systems, including beta-cyclodextrin and cupric, ion and its complexes with bio-functionalized ligands, were considered for their ability in protecting cell membranes from the damage, which is photoin duced by superoxide anion, free radicals and singlet oxygen.