Protection of DNA and cellular membranes from reactive oxygen species mediated damage by uric acid.
Leonard-SS; Blemings-KP; Shi-X; Klandorf-H
FASEB J 2003 Mar; 17(5)(Part 2):A1257
The objective of the present study was to investigate the quenching effect of uric acid on specific ROS and determine the ability of UA to protect DNA and cellular membranes from ROS mediated damage. Hydroxyl (OH) and superoxide (O2) radicals were detected with electron spin resonance (ESR). OH radicals generated via the Fenton reaction and O2 radicals were created using xanthine and xanthine oxidase. Hydroxyl and superoxide radical ESR signals were both reduced by addition of uric acid in a concentration dependent manner (P < .05). The ability of uric acid to protect DNA from hydroxyl damage was determined by exposure of gamma Hind III DNA fragments to the Fenton reaction. Uric acid inhibited hydroxyl mediated DNA damage, indicated by the presence of intact bands of gamma Hind III DNA after agarose gel electrophoresis and ethidium bromide staining. Lipid peroxidation, a marker of cellular injury by ROS, was induced in RAW 264.7 cells by exposure to Minn-U-Sil, a silica based stimulant of ROS production. Peroxidation of cellular membranes, detected using spectroscopy, was less (P < .015) with addition of 1mM uric acid to the cell incubation mixture. The results of these studies demonstrate uric acidís ability to scavenge hydroxyl and superoxide radicals, thus protecting against both DNA damage and lipid peroxidation.
Cell-biology; Cell-function; DNA-damage; Cellular-reactions; Lipid-peroxidation; Lipids
Abstract; Conference/Symposia Proceedings
The FASEB Journal, Experimental Biology 2003, San Diego, California, April 11-15, 2003