Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.17.3.2 (xanthine oxidase)
 8,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vitro potency of neopterin (NP) as an antioxidant and its in vivo activity to suppress alloxan-induced diabetes were investigated. The reduced form of neopterin, 5,6,7,8-tetrahydroneopterin (NPH-4), showed an extremely high superoxide anion radical scavenging activity in two assay systems, i.e. xanthine/xanthine oxidase- and macrophage/phorbol myristate acetate (PMA)-reaction systems. NPH-4 also inhibited the oxidation of linoleic acid about as effectively as uric acid. Furthermore, NPH-4 and NP effectively suppressed alloxan-induced mouse diabetes. These results suggest that pteridines play an important role as endogenous antioxidants.
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PMID:Neopterin as an endogenous antioxidant. 131 24

The oxygen free radical scavenging activity of the reduced form of neopterin, 5,6,7,8-tetrahydroneopterin (NPH-4), was investigated in vitro using electron paramagnetic resonance spectroscopy. In the hypoxanthine-xanthine oxidase (HPX-XOD) reaction system, NPH-4 suppressed the production of the superoxide spin adduct, but enhanced that of the hydroxyl radical spin adduct. The hydroxyl radical spin adduct was also observed in the solution containing NPH-4 and XOD but excluding HPX. These results indicate that NPH-4 is readily oxidized to some intermediates before the reaction with oxygen free radicals and that the substance which actually serves as an antioxidant in vivo is not NPH-4 but its metabolites.
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PMID:Does the reduced form of neopterin serve as an antioxidant? 895 38