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)

Picroliv, the active principle of Picrorhiza kurrooa, and its main components which are a mixture of the iridoid glycosides, picroside-I and kutkoside, were studied in vitro as potential scavengers of oxygen free radicals. The superoxide (O2-) anions generated in a xanthine-xanthine oxidase system, as measured in terms of uric acid formed and the reduction of nitroblue tetrazolium were shown to be suppressed by picroliv, picroside-I and kutkoside. Picroliv as well as both glycosides inhibited the non-enzymic generation of O2- anions in a phenazine methosulphate NADH system. Malonaldehyde (MDA) generation in rat liver microsomes as stimulated by both the ascorbate-Fe2+ and NADPH-ADP-Fe2+ systems was shown to be inhibited by the Picroliv glycosides. Known antioxidants tocopherol (vitamin E) and butylated hydroxyanisole (BHA) were also compared with regard to their antioxidant actions in the above system. It was found that BHA afforded protection against ascorbate-Fe(2+)-induced MDA formation in microsomes but did not interfere with enzymic or non-enzymic O2- anion generation; and tocopherol inhibited lipid peroxidation in microsomes by both prooxidant systems and the generation of O2- anions in the non-enzymic system but did not interfere with xanthine oxidase activity. The present study shows that picroliv, picroside-I and kutkoside possess the properties of antioxidants which appear to be mediated through activity like that of superoxide dismutase, metal ion chelators and xanthine oxidase inhibitors.
 ...
PMID:Picroliv, picroside-I and kutkoside from Picrorhiza kurrooa are scavengers of superoxide anions. 132 26

Involvement of free radicals and their scavenging enzymes in mice pulmonary thromboembolism, induced by intravenous infusion of collagen and adrenaline, has been studied. Malonaldehyde (MDA) and activities of xanthine oxidase (XO), catalase (CAT) and superoxide dismutase (SOD) were estimated in platelets, heart and lung homogenates. MDA increased in all the tissues sharply, while animals showed 70-80% thrombocytopenia. Xanthine oxidase activity in these animals increase significantly in heart. However, increased SOD activity and decreased catalase activity was observed in platelets. Intravenous administration of superoxide dismutase (5 mg/kg), catalase (5 mg/kg) and mannitol (200 mg/kg) protected the mice against pulmonary thromboembolism. The importance of free radicals in mice pulmonary thromboembolism has been demonstrated.
 ...
PMID:Role of free radicals in pulmonary thromboembolism in mice. 251 Mar 58

Xanthine (X) and xanthine oxidase (XO) were injected intratracheally (IT) in hamsters at Day 0 (38 mg X, 100 micrograms XO) and Day 5 (38 mg X, 250 micrograms XO). Control hamsters received saline or X (38 mg) plus boiled XO (100, 250 micrograms). Cytoplasmic superoxide dismutase (SOD) activity increased from control of 286 to 337 and 335 units/lung at Days 12 and 19, respectively, but decreased to 228 units/lung at Day 33; mitochondrial SOD activity increased at Day 12 from control of 57 to 71 units/lung and then decreased at Days 26 and 33 to 42 and 33 units/lung, respectively. Glutathione peroxidase (GP) and glutathione reductase (GR) activities rose from their control values of 1161 and 1151 to 1561 and 2287 units/lung at Day 12, respectively; thereafter, GR activity decreased to 512 and 462 units/lung at Days 19 and 26, respectively. Glutathione transferase declined at Day 12 but increased at Day 26 after initial treatment. Glucose-6-phosphate dehydrogenase activity declined from control of 1071 to 693 units/lung at Day 2 and returned to control thereafter. Catalase activity remained unaffected. Hydroxyproline was increased from 903 micrograms/lung in control to 1080, 1301, 1195, and 1148 micrograms/lung at Days 12, 19, 26, and 33, respectively. Malonaldehyde increased from 40 nmole/lung in control to 70 and 113 nmole/lung at Days 12 and 33, respectively. The ratio of right ventricle to left ventricle and septum increased significantly from control of 0.277 to 0.318 at Day 33. Histopathology at Days 2 and 4 revealed peribronchiolar and arteriolar inflammation, and diffuse alveolitis. By Day 12 there were thickened alveolar septa and foci of fibrotic consolidation.
 ...
PMID:Effects of intratracheal administration of xanthine plus xanthine oxidase on lung antioxidant enzymes, lipid peroxidation, and collagen in hamsters. 319 17