title: Combined in vitro assay for photohaemolysis and haemoglobin oxidation as part of a phototoxicity test system assessed with various phototoxic substances.
abstract: 12 well-known phototoxicants used in the EC/COLIPA (The European Cosmetic, Toiletry and Perfumery Association) interlaboratory validation trial on 'Photoirritation in vitro' have been analysed in view of their ability to induce photohaemolysis. As well as, or instead of, this effect, oxidative reactions involving oxyhaemoglobin have been monitored, by assessing intra- and extracellular methaemoglobin formation, as an additional parameter in the screening of deleterious photoeffects on the cellular protein of red blood cells. A combination of both photohaemolysis and photo-oxidation of haemoglobin is proposed for the investigation of light-induced toxicity in an in vitro test system. Piroxicam and 8-methoxypsoralen did not produce any marked phototoxic alterations in this system. Rose bengal and amiodarone demonstrated predominantly membrane effects, whereas the antibiotics tetra- and doxycycline damaged exclusively the intracellular haemoglobin. All other phototoxins caused both photohaemolysis and photo-oxidation of haemoglobin.
authors.affiliation: Beiersdorf AG, PGU-Research Center-Cosmed Division, 4232 Dept. Biocompatibility, Unnastrasse 48, D-20245 Hamburg, Germany.
authors.forename: W J
authors.initials: WJ
authors.lastname: Pape
authors.forename: M
authors.initials: M
authors.lastname: Brandt
authors.forename: U
authors.initials: U
authors.lastname: Pfannenbecker