Onion (Allium Cepa) contains high levels of flavonoids. Although there are many studies indicating the inhibitory effects of flavonoids on xanthine oxidase, there is no report on the effect of onion on this enzyme. Therefore, in the present study, the inhibitory effects of onion on xanthine oxidase are investigated. Fresh filtered juice of onion was prepared and its inhibitory effect on guine...

In liver cells isolated from fed female rats, glucagon (290nM) increased adenosine 3':5'-monophosphate (cyclic AMP) content and decreased cyclic AMP binding 30 s after addition of hormones. Both returned to control values after 10 min. Glucagon also stimulated cyclic AMP-independent protein kinase activity at 30 s and decreased protein kinase activity assayed in the presence of 2 muM cyclic AMP...

complex reacted rapidly with 02-. in a catalytic manner. The rate constant for O,-* dismutation was determined by competition of the iron porphyrin with Nitro Blue Tetrazolium in a xanthine/xanthine oxidase system at pH 10.1 ; a value of 3 x ~O'M-' .s-' at 20°C was obtained. The iron porphyrin had no effect on xanthine oxidase activity. Under our reaction conditions, at least 14 molecules of Oz...

Using oxygen uptake as an index of the physiological response of isolated parietal cells, the interactions between histamine and gastrin and between histamine and carbamylcholine and the effects of atropine and metiamide on these interactions have been studied. Parietal cells were isolated from canine fundic mucosa by sequential exposure of separated mucosa to collagenase and EDTA. In previous ...

Xanthine oxidase has been hypothesized to be an important source of biological free radical generation. The enzyme generates the superoxide radical, .O2- and has been widely applied as a .O2- generating system; however, the enzyme may also generate other forms of reduced oxygen. We have applied electron paramagnetic resonance (EPR) spectroscopy using the spin trap 5,5'-dimethyl-1-pyrroline-N-ox...

Fennel, Foeniculum vulgare Mill. (Apiaceae) is an aromatic plant, with medicinal and culinary applications, widely naturalized worldwide, especially near the see coasts and riversides. Fennel has long been used in Iran as a traditional remedy against gout. The objective of our study was to uncover the scientific basis of this traditional gout therapy. Different plant parts were extracted by met...

A quantitative determination method using HPLC with fluorescence detection for the xanthine derivative 3-methyl-8-(piperazin-1-yl)-7-(thietan-3-yl)-1-ethyl-1H-purine-2,6(3H,7H)-dione hydrochloride (Angipur drug substance) in donor blood plasma was developed and validated. The optimal conditions of Angipur substance were KH2PO4 buffer (50 mM, pH 6.5); aqueous-to-organic phase ratio 55:45 v/v; ad...

onion (allium cepa) contains high levels of flavonoids. although there are many studies indicating the inhibitory effects of flavonoids on xanthine oxidase, there is no report on the effect of onion on this enzyme. therefore, in the present study, the inhibitory effects of onion on xanthine oxidase are investigated. fresh filtered juice of onion was prepared and its inhibitory effect on guinea ...

1. Extracts prepared from tea leaves with Polyclar AT (insoluble polyvinylpyrrolidine) contained two methyltransferase activities catalysing the transfer of methyl groups from S-adenosylmethionine to 7-methylxanthine, producing theobromine, and to theobromine, producing caffeine. 2. The methyltransferases exhibited the same pH optimum (8.4) and a similar pattern of effects by metal ions, thiol ...