Protective Action of Cerium Dioxide Nanoparticles on Human Serum Albumin in a Model of Nitrosative Stress

A protective effect of CeO2 nanoparticles on human serum albumin (HSA) under nitrosative stress induced by peroxynitrite (ONOO–) was demonstrated. The effect of nanodisperse CeO2 and ONOO– on the tryptophan fluorescence of purified HSA, as well as albumin isolated from biological fluids, blood plasma, peritoneal (ascitic), and synovial (joint) fluids, was examined for the first time by fluorescence spectroscopy. ONOO– decreased the intrinsic fluorescence of HSA, whereas preliminary incubation of the protein with a CeO2 sol markedly attenuated this effect. In the presence of nanodisperse CeO2, the degree of oxidative modification of albumin induced by ONOO– decreased by ~20%. The results further indicate the substantial potential of nanodisperse CeO2 for biomedical applications.