TY - JOUR
T1 - Free radical scavenging, DNA protection, and inhibition of lipid peroxidation mediated by uric acid
AU - Stinefelt, Beth
AU - Leonard, Stephen S.
AU - Blemings, Kenneth P.
AU - Shi, Xianglin
AU - Klandorf, Hillar
PY - 2005/12
Y1 - 2005/12
N2 - Uric acid (UA) has been proposed to be the dominant antioxidant in birds. The objective of this study was to investigate the quenching effect of varying concentrations of UA, including those found in avian plasma, on specific reactive oxygen species (ROS) and to determine the ability of UA to protect DNA and cellular membranes from ROS-mediated damage. Hydroxyl (asterisk inside a circle signOH) and superoxide (O2asterisk inside a circle sign -) radicals were detected by electron spin resonance (ESR) and their presence was reduced following addition of UA (p <0.05) in a concentration-dependent manner. UA inhibited hydroxyl-mediated DNA damage, indicated by the presence of more precise, dense bands of λ Hind III DNA after agarose gel electrophoresis and ethidium bromide staining (p <0.05). Lipid peroxidation of silica-exposed RAW 264.7 cell membranes was diminished (p <0.02) after addition of UA to the cell incubation mixture. These studies demonstrate that UA scavenges hydroxyl and superoxide radicals and protects against DNA damage and lipid peroxidation. These results indicate specific antioxidant protection that UA may afford birds against ROS-mediated damage.
AB - Uric acid (UA) has been proposed to be the dominant antioxidant in birds. The objective of this study was to investigate the quenching effect of varying concentrations of UA, including those found in avian plasma, on specific reactive oxygen species (ROS) and to determine the ability of UA to protect DNA and cellular membranes from ROS-mediated damage. Hydroxyl (asterisk inside a circle signOH) and superoxide (O2asterisk inside a circle sign -) radicals were detected by electron spin resonance (ESR) and their presence was reduced following addition of UA (p <0.05) in a concentration-dependent manner. UA inhibited hydroxyl-mediated DNA damage, indicated by the presence of more precise, dense bands of λ Hind III DNA after agarose gel electrophoresis and ethidium bromide staining (p <0.05). Lipid peroxidation of silica-exposed RAW 264.7 cell membranes was diminished (p <0.02) after addition of UA to the cell incubation mixture. These studies demonstrate that UA scavenges hydroxyl and superoxide radicals and protects against DNA damage and lipid peroxidation. These results indicate specific antioxidant protection that UA may afford birds against ROS-mediated damage.
KW - DNA oxidation
KW - Electron spin resonance
KW - Lipid peroxidation
KW - Oxidative stress
KW - Uric acid
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M3 - Article
C2 - 15830708
AN - SCOPUS:15444371172
SN - 0091-7370
VL - 35
SP - 37
EP - 45
JO - Annals of Clinical and Laboratory Science
JF - Annals of Clinical and Laboratory Science
IS - 1
ER -