HYDROXYL RADICAL-SCAVENGING ACTIVITY OF CARNOSINE - A SPIN TRAPPING STUDY

Carnosine (beta-alanyl-L-histidine) was described as an effective protector of biological membranes against lipid peroxidation, probably because of its scavenging properties, found recently in some biological systems. To understand better the protective function of this, natural histidine-containing dipeptide, its interaction with hydroxyl radical has been studied with the use of spin traps, alpha-phenyl-N-tert-butyl nitrone (PBN) and 5,5-dimethylpyrroline-1-oxide (DMPO). Carnosine decreases significantly the amount of PBN/.OH and DMPO/.OH radical adducts formed in aqueous solution of H2O2 after UV-irradiation or during the Fenton reaction induced by FeCl2. In addition, carnosine decreases drastically the life-time of DMPO/.OH in H2O2 solution. It is concluded that carnosine is an efficient scavenger of hydroxyl radical and interacts also with the radical adducts of the spin traps used.