The endogenous reactive oxygen species ("ROS") formation is associated with many pathologic states such as inflammatory diseases, neurodegenerative diseases, brain and heart ischemic injuries, cancer, and aging. The purpose of this study was to investigate the endogenous sources for "ROS" formation in intact isolated rat hepatocytes, in particular, peroxisomal oxidases, monoamine oxidase, xanth...

Anacardic acid C15:3 and cardol C15:3 sigmoidally suppressed superoxide anion (O2-) generation using xanthine oxidase. To study this suppression activity, anacardic acids, cardanols and cardols having different numbers of double bonds in alk(en)yl chains were prepared. The O2- scavenging activity and H2O2 formation from O2- using PMS-NADH were examined. Anacardic acids and cardols indicated sig...

Various dietary flavonoids were evaluated in vitro for their inhibitory effect on xanthine oxidase, which has been implicated in oxidative injury to tissue by ischemia-reperfusion. Xanthine oxidase activity was determined by directly measuring uric acid formation by HPLC. The structure-activity relationship revealed that the planar flavones and flavonols with a 7-hydroxyl group such as chrysin,...

Some medicinal plants from Papua have been used traditionally as hyperuricemia and antioxidant agents for many ethnic in Islands. The present study aims to evaluate inhibitory xanthine oxidase, antioxidative activities, total phenolic, flavonoid of five selected plants, Myrmecodia beccarii , Villebrunea rubescens Breynia cernua Bridelia spp. Dodonaea viscosa . Preliminary phytochemical screenin...

The endogenous reactive oxygen species ("ROS") formation is associated with many pathologic states such as inflammatory diseases, neurodegenerative diseases, brain and heart ischemic injuries, cancer, and aging. The purpose of this study was to investigate the endogenous sources for "ROS" formation in intact isolated rat hepatocytes, in particular, peroxisomal oxidases, monoamine oxidase, xanth...

The xanthine oxidase activity of mouse regenerating liver has been shown to be elevated during the period of rapid liver growth and proliferation. This increase is evident when the enzyme activity is expressed per unit wet tissue weight, per unit nitrogen, or per cell. The adrenal cortex probably plays only a minor role in implementing this phenomenon. Further augmentation of the xanthine oxida...

An optimum way of immobilizing xanthine oxidase on graphite was found where a redox transformation of the enzyme was observed. The nature of the redox maxima was hypothesized on the basis of the dependence of the half-wave potential (Ep/2) on the pH of the solution. The enzymatic activity of xanthine oxidase adsorbed on two kinds of soot was studied by the oxidation of xanthine. The kinetic and...

Inhibition of xanthine oxidase by folic acid was reexamined after complete removal of the contaminant which was responsible for time-dependent inactivation (Lewis, A. S., Murphy, L., Mcalla, C., Fleary, M., and Purcell, S. (1984) J. Biol. Chem. 259, 12-15; Spector, T., and Ferone, R. (1984) J. Biol. Chem. 259, 10784-10786). From turnover experiments using stopped flow equipment with a limited a...

The enzyme, xanthine oxidase, has been implicated as a major source of destructive free radicals in ischemia-reperfusion injury associated with a range of pathological states [l]. Enzymic activity has been detected in many mammalian tissues [4] by using, variously, spectrophotometric [51, radiometric[6] and fluorimetric [71 assays. Apart from bovine milk fat globule membrane, which has long pro...