PHOTOTOXIC POTENTIALITIES OF TARTRAZINE: SCREENING TESTS

Abstract Tartrazine (TRT) a cosmetics, food and drug additive, was tested with respect to phototoxic potentialities. Although, using the cholesterol technique, TRT did not appear to produce any ¹O₂ upon visible light irradiation, the EPR spin trapping experiments with 5,5-dimethyl-1-pyrroline-N-oxide, as spin trap, were in favour of activated oxygen species (O₂^˙, OH^˙) and hydrated electron production by photoexcited TRT.
Irradiation of TRT with complementary biological systems (nucleic acids, bacteria, biological membranes) showed that few of them can be damaged by this photosensitizer. Tartrazine could induce a weak deoxyribose degradation but did not produce any DNA strand breaks on isolated φXRFI DNA. Tartrazine was detected as mutagen in the Salmonella microsome (Ames) assay, only in conjunction with visible light. In the presence of photoexcited TRT, erythrocyte membranes were damaged by covalently cross-linking proteins.
The tests developed here seem thus to be suitable for detecting any unwanted phototoxic activity associated with potential photosensitizers.