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

Hypouricemic and antioxidant activities of Allium cepa Lilliaceae and quercetin in normal and hyperuricemic rats

To evaluate the hypouricemic and antioxidant effects of Allium cepa Lilliaceae [Allium cepa L.] and quercetin in normal and hyperuricemic rats. The following study was conducted in the Department of Nutrition and Biochemistry, Tehran University of Medical Science, Iran, between May 2007 and March 2008. A total of 48 male Wistar rats [body weights: 180-200 g] were randomly divided into 8 equal groups including normal; normal + Allium cepa L. [5g/kg]; normal + quercetin [5mg/kg]; normal + allopurinol [5mg/kg]; hyperuricemic; hyperuricemic + Allium cepa L. [5g/kg]; hyperuricemic + quercetin [5mg/kg]; hyperuricemic + allopurinol [5mg/kg] once a day for 14 days. Experimentally, hyperuricemia in rats was induced by intraperitoneal injection of potassium oxonate [250mg/kg]. Allium cepa L. and quercetin treatments for 14 days significantly reduced [p=0.000] the serum uric acid levels of hyperuricemic rats in a time-dependent manner. All treatments significantly inhibited hepatic xanthine oxidase/xanthine dehydrogenase activity. Allium cepa L. and quercetin treatments led also to a significant improvement in biomarkers of oxidative stress in hyperuricemic rats [p=0.000]. Although the hypouricemic effect of allopurinol was much higher than that of Allium cepa L. and quercetin, it could not significantly change oxidative stress biomarkers. These results may be responsible partly for the beneficial effects of Allium cepa L. and its major flavonoid on hyperuricemia and oxidative stress

Efectos del Allopurinol sobre el riñón: su relación con los radicales libres del oxígeno / Effect of allopurinol over the kidney: oxygen free radical relation

Para dilucidar los mecanismos tóxicos responsables de la nefrotoxicidad inducida por el Allopurinol y las respuestas protectoras endógenas, se investigaron las variaciones de la Creatinina plasmática, la peroxidación lipídica renal, los factores de producción de radicales libres del O2: xantina oxidasa y sus sustratos: xantina e hipoxantina y los factores de eliminación de tales radicales: superóxido dismutasa y catalasa. Las ratas recibieron subcutáneamente inyecciones de Allopurinol en dosis de 100 mg/kg de peso, por día y durante tres días. Comparando ratas normales, se observaron los siguientes cambios: a) un aumento en las proporciones de creatinina plasmática y en los niveles tisulares de la catalasa y de la supeóxido dismutasa; c) los valores máximos y mínimos se observaron al tercer día de administración de la droga y posteriormente todos los parámetros se normalizan a sus niveles originales; d) estos resultados sugieren que la nefrotoxicidad del Allopurinol se atribuiría al aumento de la peroxidación lipídica, que por un lado, aumenta la producción de radicales libres del O2, y por otro lado, estarían dismunuidos los mecanismos de su eliminación