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

Effects of nibbling and gorging on lipid profiles, blood glucose and insulin levels in healthy subjects

Although there is some evidence indicative of some beneficial effects of an increased meal frequency on the lipid profiles, the results published are controversial. The aim of the present study is to investigate the effects of feeding frequency on blood lipids, glucose and insulin. The subjects of this study were 15 healthy non-smoker males aged 27.2 +/- 6.4 years. All subjects were placed on 2 identical diets in which they consumed the same food either as 3 meals at 7-hours intervals [gorging diet] or as 9 snacks at 2 hours intervals [nibbling diet]. Each diet was of 2 week's duration and was separated from each other by a period of 3 weeks. At the end of both diets, the plasma was obtained from fasting blood samples and its lipid levels were determined. The study was carried out in Tabriz University of Medical Sciences, Tabriz, Iran between 30 October 1998 and 19 December 1998. The nibbling diet was associated with an increased level of glucose [p<0.01] and a decreased level of insulin [p<0.05]. The plasma levels of total cholesterol, triglyceride, low-density lipoprotein, and lipoprotein [a] were found to be lower in the end of nibbling diet compared with the gorging diet, however, only for the last parameter this reduction was significant [p<0.02]. The nibbling diet resulted in an insignificant increase in the high-density lipoprotein concentration. Taking into account, the difficulty in following the nibbling diet with a fear of weight gain, there would be no advantages in recommending the nibbling dietary pattern for normal free-living subjects, although its metabolic benefits in obese people could be the subject for further studies