Topic
Xanthine
About: Xanthine is a research topic. Over the lifetime, 4046 publications have been published within this topic receiving 129820 citations. The topic is also known as: Xanthine.
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TL;DR: It is concluded that chrysoeriol exhibits potent antioxidant activity and is a more efficient scavenger of DPPH radicals and a better inhibitor of xanthine/xanthine oxidase than the aglycone.
83 citations
TL;DR: It is suggested that caffeine may suppress LPS-induced inflammatory responses in RAW264.7 cells by regulating NF-κB activation and MAPK phosphorylation.
83 citations
TL;DR: The results suggest that superoxide is the primary damaging species and a potential role of xanthine oxidase-generated superoxide in oxidative damage to vascular smooth muscle during a number of pathophysiological conditions.
Abstract: Effects of reactive oxygen intermediates generated by hypoxanthine plus xanthine oxidase on the Ca(2+)-adenosinetriphosphatase (ATPase) of sarcoplasmic reticulum from bovine aortic smooth muscle were studied. Exogenous hypoxanthine (0.1-100 microM) plus xanthine oxidase (10 mU/ml) produced an hypoxanthine concentration-dependent inhibition of the Ca(2+)-ATPase. The inhibition could be completely blocked by superoxide dismutase (100 U/ml) but not by either mannitol (20 mM) or deferoxamine (100 microM). Direct addition of hydrogen peroxide in the micromolar range did not cause significant inhibition. These results suggest that superoxide is the primary damaging species. Cysteine blocked this inhibition, suggesting possible involvement of sulfhydryl groups in the inhibition mechanism. Additionally, 1.16 +/- 0.17 mU/g wet wt of xanthine oxidase activity was detected in the postnuclear supernatant of bovine aortic smooth muscle, suggesting the existence of a possible intracellular source of superoxide. This value was calculated to be approximately 5 mU/ml by using a usual value of vascular smooth muscle cellular volume. Thus the level of endogenous xanthine oxidase in vascular smooth muscle is comparable with the level of exogenous xanthine oxidase used in the present study. These findings suggest a potential role of xanthine oxidase-generated superoxide in oxidative damage to vascular smooth muscle during a number of pathophysiological conditions.
83 citations
TL;DR: The aim of this study was the electrochemical detection of the adenosine-3-phosphate degradation product, xanthine, using a newxanthine biosensor based on a hybrid bio-nanocomposite platform which has been successfully employed in the evaluation of meat freshness.
83 citations
TL;DR: The successful expression of recombinant P. falciparum HGXPRT in Escherichia coli has now been achieved and the enzyme purified to homogeneity in mg quantities, and a method to stabilise the activity and to reactivate inactive samples has been developed.
83 citations