Abstract
By means of a sensitive chemiluminescence's method, toxicity of fenofibric acid was demonstrated on respiratory burst of UVA-irradiated peripheral blood polymorphonuclear cells (PMNs). Through this method, it was possible detect such phototoxic effect at a minor concentration of fenofibric acid as compared with those previously reported in photohemolysis test. This effect was not related with losses of cell viability because PMNs did not lose its capabilities for excluding the trypan blue dye, when irradiated in presence of drug. In order to explain the results obtained in presence of scavengers of different reactive oxygen species, it was proposed a singlet oxygen-mediated (type II) mechanism of photosensitization and/or through formation of toxic photoproducts.