Excess of uric acid is mainly treated with xanthine oxidase (XO) inhibitors, also called uricostatics because they block the conversion of hypoxanthine and xanthine into urate. Normally, accumulation of upstream metabolites is prevented by the hypoxanthine-guanine phosphoribosyltransferase (HPRT) enzyme. The recycling pathway, however, is impaired in the presence of HPRT deficiency, as observed...

the hptlc analysis, antioxidant, and antigout activity of asparagus racemosus, withania somnifera, vitex negundo, plumbago zeylanica, butea monosperma and tephrosia purpurea extracts were investigated. the chemical fingerprinting were carried out by high performance thin layer chromatography (hptlc), antioxidant activity by abts, dpph, frap radical scavenging assays, and antiogout activity by c...

flavonoids could serve as potent inhibitors of xanthine oxidase (xo). in the present study, the effects of ruta graveolens l. extract and its major isolated flavonoids, quercetin and rutin, on guinea pig liver xo have been investigated. the inhibitory effects of r. graveolens, quercetin and its glycoside form, rutin, were assayed spectrophotometrically. r. graveolens extract showed moderate inh...

In 1948 Miller (1) demonstrated that the loss of liver xanthine oxidase activity in the rat greatly exceeded the loss of liver protein during acute inanition. Moreover, xanthine oxidase appeared to be the most labile of the four liver enzymes studied. Westerfeld and Richert (2) observed that increasing the level of protein in the diet tended to bring about an increase in liver xanthine oxidase ...

During the acute phase of myocardial ischemia, adenine nucleotides are degraded to nucleosides and bases, especially inosine and hypoxanthine. Simultaneously, xanthine dehydrogenase is converted to xanthine oxidase, an enzyme that converts hypoxanthine to xanthine, and xanthine to uric acid, producing a superoxide anion for each molecule of hypoxanthine or xanthine oxidized. To determine if fre...

The products of the activity of xanthine oxidase (EC 1.2.3.2) include such reactive substances as H,O,, singlet oxygen and the superoxide and hydroxyl free radicals (KeUogg & Fridovich, 1975), which are currently receiving considerable attention not only because they lead to the formation of lipid hydroperoxides, but also because the latter may promote the formation of prostaglandins (Hemler et...

conclusions this study supports the preventative effects of aminophylline on apnea in extreme premature infants. in other words, the more premature an infant, the greater the preventative effect of aminophylline on the incidence of apnea and bradycardia. background a few studies have been carried on preventive drugs for apnea of preterm neonates. objectives this study aimed to assess the safety...

The oxidation of hypoxanthine to xanthine and of xanthine to uric acid is catalysed by xanthine oxidase (EC 1.2.3.2). This enzyme has been considered to be an oxidase in mammalian organs (De Renzo, 1956), whereas it is a dehydrogenase in the organs of birds, with NAD+ probably being the physiological electron acceptor (Morell, 1955a,b; Fellig & Wiley, 1958). We have reported that in freshly pre...