RT Journal Article
SR Electronic
T1 Elevated Plasma Levels of Bilirubin in Patients with Neurotrauma Reflect its Pathophysiological Role in Free Radical Scavenging
JF In Vivo
JO In Vivo
FD International Institute of Anticancer Research
SP 855
OP 860
VO 19
IS 5
A1 KENJI DOHI
A1 KAZUE SATOH
A1 HIROKAZU OHTAKI
A1 SEIJI SHIODA
A1 YASUFUMI MIYAKE
A1 MASATERU SHINDO
A1 TOHRU ARUGA
YR 2005
UL http://iv.iiarjournals.org/content/19/5/855.abstract
AB Bilirubin, a powerful endogenous antioxidant, is one of the catabolites of heme oxygenases (HOs). In this study, the plasma bilirubin concentration was measured to establish bilirubin kinesis after traumatic brain injury (TBI). Furthermore, in in vitro studies, the free radical scavenging activity and antioxidant potency of bilirubin was also investigated at various concentrations, including physiological ones. Indirect plasma bilirubin was measured in 25 patients on days 1, 2, 3 and 4 after presentation with TBI. The ability of bilirubin to scavenge the hydroxyl (OH.) and 1,1-diphenyl-2-picrylhyrazyl (DPPH) radicals, and its antioxidant potency, were also analyzed using electron spin resonance (ESR) and the bioantioxidant power (BAP) methods, respectively. Plasma bilirubin levels were significantly higher on days 2, 3 and 4 than on patient admission (day 1; p<0.05). ESR and BAP results revealed that bilirubin has direct OH. and DPPH radical scavenging activities and potent antioxidant effects in vitro at physiological concentrations. These data indicate that physiological concentrations of bilirubin have antioxidant properties and that it constitutes one of the biological defense mechanisms in neurotrauma patients. Copyright © 2005 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved