Antihyperuricemic and diuretic effects of procyanidins extracted from Crataegus monogyna

Data indicated that procyanidins extracted from grape seeds has uric acid lowering effects in mice, however the hypouricaemic effect of procyanidins was accompanied with changes in enzymatic activities of xanthine dehydrogenase and xanthine oxidase. This study was designed to investigate the effect of procyanidins extracted from Crataegus monogyna on serum uric acid, adenosine deaminase [ADA], 5-nucleotidase, xanthine oxidase, and renal function on normal and potassium oxonate induced hyperuricemic rats. Thirty female albino rats were divided into three groups. The first group included 18 rats pretreated with the uricase inhibitor potassium oxonate [250 mg/kg, i.p.], served as an animal model for hyperuricemia. The rat models were divided into three subgroups, each subgroup having six rats. The first subgroup served as a normal control. Subgroup 2 received a single daily dose [100 mg/kg p.o] of procyanidins for 7 days. The third subgroup received daily dose [50 mg/kg p.o] of allopurinol for 7 days as positive control. The second group included six rats received only water as a vehicle. The serum uric acid, xanthine oxidase, adenosine deaminase [ADA] and 5-nucleotidase levels were measured and com-pared to those in normal untreated control group. The Third group included six normal rats received a single dose of Procyanidins [50 mg/kg body weight; i.v.] to study the renal ef-fects of procyanidins.. A single daily dose [100 mg/kg PO] of procyanidins for 7 days significantly reduced serum levels of uric acid, ADA and 5'-nucleotidase, without detectable effects on the level of xanthine oxidase in hyperuricemic rats. Intravenous infusion of a single dose of procyanidins [50 mg/kg i.v] produced marked increases in urinary Na+excretion [4.8 folds] and urine flow [2.6 folds] accompanied by insignificant change of potassium excretion in the rats. The reduction in serum uric acid most probably is due to inhibiting enzymes, ADA and 5-nucleotidase. The antihyperuricemic and diuretic effects of procyanidins recommended it as a good drug for the treatment of gout and renal uric acid calculi

Effects of Supplementation with a Selective COX-2 Inhibitor and Vitamin C on Glomerular TGF-beta, COX-2, and Antioxidant Activity in Rats with Passive Heymann Nephritis / 대한신장학회지

PURPOSE: In the passive Heymann nephritis (PHN) rat model of membranous nephropathy, complement induces glomerular epithelial cell injury and proteinuria, which is partially mediated by reactive oxygen species (ROS), TGF-beta, and COX-2. In the current study, we determined the effect of a selective COX-2 inhibitor (celecoxib) and vitamin C on the enzyme system associated with ROS, TGF-beta, and COX-2 in PHN. METHODS: Four groups of rats with PHN were dosed with polyethylene glycol vehicle (P; n=4), celecoxib (COXi; n=8), vitamin C (VC; n=8), or celecoxib and vitamin C (COXi+VC; n=8) from days 7-21. Each group was then divided into 2 subgroups reflecting the day of the experiment (day-14 and -21 subgroups). RESULTS: The urine protein was significantly reduced in the VC and COXi+VC groups (subgroup day- 14) compared to the P group (p<0.05). The glomerular TGF-beta expression was reduced in the COXi+ VC group (subgroup day-21) compared to the P group (p<0.05). Glomerular COX-2 expression was increased in the COXi, VC, and COXi+VC groups compared to the P group (p<0.05). The COXi, VC, and COXi+VC groups (subgroup day-21) had decreased activity of lipid peroxide and xanthine oxidase and increased activity of xanthine dehydrogenase, superoxide dismutase, GSH-Px, and catalase. This antioxidant activity was highest in the COXi+VC group (p<0.05). CONCLUSION: Selective COX-2 inhibitors possess antioxidant effects. The combination of a COX-2 inhibitor and vitamin C was more effective than COX-2 inhibitor or vitamin C alone in increasing antioxidant activity and decreasing TGF-beta.

Anti-xanthine oxidase antibodies in sera and synovial fluid of patients with rheumatoid arthritis and other joint inflammations

To study anti-bovine milk xanthine oxidoreductase XOR antibody levels in synovial fluid as well as in serum of patients suffering from rheumatoid affections to assess a possible correlation between antibody titres and severity of disease. Sera and synovial fluids were collected from volunteer donors at Setif University Hospital, Setif, Algeria from 2001-2007 with the consent of patients. Human IgG and IgM levels of free and bound anti-bovine milk XOR antibodies were determined using bovine XOR as antigen, with enzyme-linked immunosorbent assay ELISA. Serum IgG anti-bovine milk XOR titres in 30 healthy normal subjects 2.74 +/- 2.31 microgram/mL are in agreement with that reported in the literature. Immunoglobulin G and IgM anti-bovine milk XOR antibody titres were found to be significantly higher in serum from patients with rheumatoid arthritis RA, and latex positives subjects. Synovial IgM antibody titres to bovine XOR were found to be significantly higher in rheumatoid arthritis patients compared to patients with other joint inflammations. In rheumatoid arthritis patients, high concentrations of antibodies against XOR were noticed. These antibodies may play a major role in RA by inhibiting both xanthine and NADH oxidase activities of XOR. They may also play a key role in eliminating XOR from serum and synovial fluid positive role but unfortunately, immune complex formation could also activate complement and participate in self maintenance of inflammation

Change of Plasma Xanthine Oxidase Activity by Intermittent Hepatic Ischemia-Reperfusion / 대한마취과학회지

BACKGROUND: The pringle maneuver (PM), hepatic inflow occlusion, during hepatic surgery reduces intraoperative bleeding and blood transfusion requirement, but hepatic ischemia/reperfusion injury is inevitable. During ischemia, xanthine oxidoreductase is converted to xanthine oxidase (XO), which can serve as a critical source of reactive oxygen species (reduces O2 to O2 .-) that contribute to inflammatory signaling, ischemia-reperfusion injury, and an impaired vascular function. The purpose of the present study was to follow changes of XO activity and O2 .- production during hepatic surgery under PM. METHODS: Eleven patients that underwent hepatectomy under intermittent PM were studied. Blood was withdrawn before PM, and 10 and 20 minutes after final reperfusion. Plasma XO activity was measured using a spectrophotometer after incubating plasma with/without xanthine for one-hour. Superoxide (O2 -) production was followed by measuring by cytochrome c reduction by plasma XO. RESULTS: After final reperfusion, plasma XO activity had increased four-fold (0.36 +/- 0.06 to 1.25 +/- 0.25 mU/ml) with a concomitant increase in O2 .- production (0.66 +/- 0.29 to 1.66 +/- 0.40microM/min). CONCLUSIONS: Significantly more XO is released into the systemic circulation after intermittent PM, with subsequently increased O2 .- production. The significant contribution of XO to hepatic surgery under PM might be beneficially managed using an anesthetic with a known antioxidative effect.

Post-irradiation free radical generation: evidence from the conversion of xanthine dehydrogenase into xanthine oxidase.

The xanthine oxidoreductase (XOR) system which consists of xanthine dehydrogenase (XDH) and xathine oxidase (XO), is one of the major sources of free radicals in biological systems. The XOR system is pre-dominantly present as XDH in normal tissues and converts into the free radical generating XO-form in the damaged tissue. Therefore, the XO-form of the XOR system is expected to be mainly found in radiolytically damaged tissues. In such an event, XO may catalyze the generation of free radicals and potentiate radiation effects in the post-irradiation period. Recent findings on the effect of ionizing radiation on the XOR system in the liver of mice, peroxidative damage and lactate dehydrogenase support this possibility. From these results it has been hypothesized that free radical generating systems could be activated in the radiolytically damaged cell and in turn contribute to the cause and complications of late effects and their persistence in post-irradiation period. This aspect may have great significance in the understanding of radiation-induced damages. It may also have serious implication in various fields like radiation therapy, health physics, carcinogenesis, space travelling radiation exposures and post nuclear accident care. Further, it is suggested that efforts need to be made to search more system(s) which could be activated particularly at lower doses of radiation to generate free radicals in the post-exposure period.

Modulation by aspartate of ischemia/reperfusion-induced oxidative stress in rat liver

Ischemia-reperfusion injury is related with oxygen free radicals; a reason which has been suggested for this is the conversion of xanthine dehydrogenase (XDH) into xanthine oxidase (XO). In the present study, metabolic control of the enzymic conversion by modulating the cellular redox potential was attempted. An amino acid, aspartate, was tested as a possible candidate on the assumption that as a participant in the malate/aspartate shuttle, it might modify the cellular NADH/NAD+ balance. Its effect was studied by measuring the level of lipid peroxidation as a thiobarbituric acid-reactive substance (TEARS) and the conversion ratio of XDH to XO in the perfused-rat livers. The experimental animals, male Sprague Dawley rats were divided into three groups: control, ischemia and ischemia/reoxygenation. To each group, aspartate was infused at 2 mM level. ischemia alone did not affect the level of TEARS or the conversion ratio of the enzyme, regardless of aspartate infusion. In contrast, reoxygenation of previously ischemia liver significantly elevated the level of TEARS and decreased the ratio of XDH to XO; both this level and this ratio were ameliorated by aspartate. The protective role of aspartate against oxidative stress induced by ischemia/reoxygenation can be explained by the fact that aspartate may correct the increased NADH/NAD ratio by facilitating NAD regeneration from NADH through the coupled aspartate aminotransferase/malate dehydrogenase reaction and the malate-aspartate shuttle. Aspartate application may thus contribute to the development of a preventive strategy against ischemia/reperfusion-induced oxidative damages.

Tiempo mínimo para detectar calidad proteica usando indicadores del catabolismo proteico en pollos / Minimal time for detecting protein quality using indicators of protein catabolism in chickens

Previous studies shown that in chickens the hepatic activities of the purine enzymes Xanthine Dehydrogenase and Nucleoside Phosphorylase and the uric acid excretion can predict the quality of the protein consumed in a very short time. In these studies even though the experimental time was short, the time used for the conditioning of the chickens was long and included five days with six chickens per cage and then five to six days for progressively changing the chickens to individual cages in order to avoid the stress associated with the isolation of the animals. Thus the purpose of this study was to determine the minimal time required to detect differences in these parameters after feeding a soy-met and a gelatin diet and eliminating completely the time required for the isolation of the chickens. Thus, 76 one day old Warren male chickens were placed in groups of six on a soy-met powdered diet during five days and on day six all the chicken were placed in individual cages and one halve was offered the same diet while the rest received a gelatin diet. Then on day 1, 2, 3, 5, 7, 10 and 15 after the diet change five chickens on each diet were sacrificed and the activity of the liver purine enzymes as well as the uric acid excreted were determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Interrelation of xanthine oxidase and dehydrogenase and L-gulonolactone oxidase in animal tissues.

There is a correlation between phylogeny and the activities of L-gulonolactone oxidase (LGO), the key enzyme responsible for ascorbic acid (AH2) synthesis in animals and total xanthine oxidase and dehydrogenase [XOD(D/O)], the enzyme responsible for the production of endogenous superoxide radical (O2-.). LGO appears in the kidneys of amphibians and reptiles but livers of mammals. XOD(D/O) also is present mainly in the kidneys of amphibians and reptiles and livers of mammals. AH2 is a potential scavenger of O2-. and it appears that tissue specific expression of LGO takes place to counteract the endogenous O2-. toxicity. The interrelation of XOD(D/O) and LGO was also observed in the liver of rats during prenatal to postnatal development.

Comparaçäo dos parâmetros cinéticos da xantina desidrogenase em neoplasia experimental / Comparation of the behavior kinetcs of the xanthine dehydrogenase in experimental neoplasms

O objetivo do presente trabalho foi de comparar os parâmetros cinéticos da xantina desidrogenase (SD) do soro de ratos normais e de ratos portadores de sarcoma induzido por 20-metilcolantreno. Foi verificado que a XD decresce no soro dos animais portadores. A afinidade da XD para com a xantina foi semelhante no soro normal e no soro de animais com sarcoma. A inativaçäo a 70C é, aparentemente, de primeira ordem em relaçäo à concentraçäo de enzima. A atividade XD foi linear durante 60 minutos de incubaçäo e a enzima do soro de aniamis com sarcoma foi mais sensível à açäo de diferentes inibidores. Concluiu-se näo haver diferença significante na estrutura de ambas as XD e que o decréscimo da atividade XD no soro de portadores de câncer indica uma baixa na concentraçäo de enzima no soro sanguíneo.

Efect of cold environment on the rat serum xanthine dehydrigenase in carbon tetrachloride poisoning

Cold acclimatization (2-5-C) not less than 20 days increases the blood serum xanthine dehydrogenase in normal as in CCl4 poisoned rats. The enzyme of the liver remains unchanged

Açäo de sais de cobre sobre a xantina desidrogenase na carcinogênese hepática de ratas / Action of copper salts on xanthine dehydrogenase in hepatic carcinogenesis of rats

Estudou-se a inibiçäo da atividade de xantina desidrogenase (XD) do soro de ratas pelo acetado de cobre (AcCu). Verificou-se também a relaçäo entre a atividade XD e a degeneraçäo hepática e carcinogênese pela D-L-etionina. Experiências mostraram que a AcCu é um potente inibidor da XD e que esta inibiçäo é näo-competitiva quando se mantém constante a concentraçäo do receptor de eletrons, e do tipo competitivo quando esta concentraçäo varia permanecendo constante a concentraçäo de substrato. Comparando-se estes estudos com os resultados da dosagem da atividade de xantina oxidase (oxigênio como receptor de eletrons) sugere-se que radicais estariam, envolvidos na açäo citotóxica do complexo AcCu-etionina com provável necessidade de ocorrência de uma reaçäo de reduçäo