Oxygen free radicals generated by xanthine oxidase have been implicated in cardiac damage. The activity of xanthine oxidase/reductase in adult rat heart is considerable. Its assay gives controversial results for other species, for example, rabbits and humans. Therefore, we perfused isolated hearts of various species, including explanted human hearts, to measure the conversion of exogenous hypox...

The structure-activity relationship of flavonoids as inhibitors of xanthine oxidase and as scavengers of the superoxide radical, produced by the action of the enzyme xanthine oxidase, was investigated. The hydroxyl groups at C-5 and C-7 and the double bond between C-2 and C-3 were essential for a high inhibitory activity on xanthine oxidase. Flavones showed slightly higher inhibitory activity t...

Xanthine oxidase is a highly versatile and ubiquitous complex molybdoflavoprotein, which controls the rate limiting step of purine catabolism pathway. Microbial xanthine oxidase can be used to address a number of questions presently not feasible with the eukaryotic enzymes. In the present study, a high-throughput microtitre plate-based colorimetric assay for xanthine oxidase producing microorga...

Experiments using purified recombinant human NAD(P)H:quinone oxidoreductase 1 (NQO1) revealed that the auto-oxidation of fully reduced protein resulted in a 1:1 stoichiometry of oxygen consumption to NADH oxidation with the production of hydrogen peroxide. The rate of auto-oxidation of fully reduced NQO1 was markedly accelerated in the presence of superoxide (O(2)(*)(-)), whereas the addition o...

the goal of this study was to investigate the common clinical chemistry and distribution of xanthine oxidase (xo) in selected tissues of a mouse model of menopause. twenty four nmri female mice were divided into three groups: normal control (nc), and ovariectomized (ovx) groups and an estrogen-treated ovariectomized (ovx+e) group which received subcutaneous injection of estradiol benzoate (2 mg...

DNA polymerase beta is required in mammalian cells for the predominant pathway of base excision repair involving single nucleotide gap filling DNA synthesis. Here we examine the relationship between oxidative stress, cellular levels of DNA polymerase beta and base excision repair capacity in vitro , using mouse monocytes and either wild-type mouse fibroblasts or those deleted of the DNA polymer...

the fruit of melia azedarach l. (meliaceae) was extracted with hexane, and its fatty acids methyl ester was analyzed using gc/ms. thirteen components representing 85.1% of the total extract were identified. the major components identified were methyl palmitate (18.8%), methyl linolenate (16.1%) and methyl linoleate (9.8%). the fruits’ extract had a lc50 of 5.5 ppm against the larvae of anophles...

OBJECTIVE Crimean-Congo hemorrhagic fever is an acute viral hemorrhagic fever with a high mortality rate. Despite increasing knowledge about hemorrhagic fever viruses, little is known about the pathogenesis of Crimean-Congo hemorrhagic fever. In this study, we measured serum adenosine deaminase and xanthine oxidase levels in Crimean-Congo hemorrhagic fever patients. METHODS Serum adenosine de...

The molecular basis for the ability of bacteria to live on caffeine as a sole carbon and nitrogen source is unknown. Pseudomonas putida CBB5, which grows on several purine alkaloids, metabolizes caffeine and related methylxanthines via sequential N-demethylation to xanthine. Metabolism of caffeine by CBB5 was previously attributed to one broad-specificity methylxanthine N-demethylase composed o...

Seventeen isoflavonoids from isoflavone, isoflavanone and isoflavan classes are selected from Dalbergia parviflora. The ChEMBL database is representative from these molecules, most of which result highly drug-like. Binary rules appear risky for the selection of compounds with high antioxidant capacity in complementary xanthine/xanthine oxidase, ORAC, and DPPH model assays. Isoflavonoid structur...