• Journal of the East Asian Society of Dietary Life
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• v.7 no.1
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• pp.21-27
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• 1997

To evaluate the effect of ethanol pretreatment on the liver and serum xanthine oxidase(XO) activity, the bromobenzene(40mg/kg body wt., i.p.) was orally given 3 times daily to the Sprague-Dawley male rats pretreated with 5% ethanol throughout 2 months. Bromobenzene treated rats pretreated with ethanol showed the more decreased activity of serum and liver XO, and lower value of V than those of only bromobenzene treated rats. Bu the bromobenzene treatment, ethanol pretreated rats showed the more decreased levels of serum alanine aminotransferase activity and liver weight/bo여 weight(%), and decreased degree of liver damage on histopathological observation than the control group.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.318-322
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• 1994

Upon gel filtration, the commercial bovine milk xanthine oxidase preparation was fractionated into two preparations showing enzyme activity. Native polyacrylamide gel electrophoresis showed that one was in a dimeric form and the other was a monomer having molecular weight of 150 kDa. It was also found that this commercial enzyme existed mostly in an active monomeric form without loss of enzyme activity. The rabbit antisera produced against two enzyme preparations cross-reacted well each other. In SDS-polyacrylamide gtel electro-phoresis, however, both enzyme preparations yielded two smaller protein bands below 150 kDa, which appeared to bind with both antisera with high affinity but not to retain enzyme activity. It implies that bovine milk xanthine oxidase can lose its activity when monomeric subunit is further degraded.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.236-240
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• 1998

The effect of thyroid hormones on the hepatic xanthine oxidase activity was studied in rats after the intraperitoneal injections of comthyroid (triiodotyronine:thyroxine=1:4) at 0.3 mg/kg for 3 consecutive days. The aim of this study was to understand the precise mechanism of hyperthyroidism induced by oxidative stress. The concentration of lipid peroxides determined indirectly by the measurement of thiobarbituric acid reactants was increased in comthyroid treated rats. The hepatic glutathione content was decreased in comthyroid injected rat compared to the euthyroid state. It was also observed that the increment of xanthine oxidase activity has a profound role in oxygen radicals generation system in comthyroid treated rat. These findings suggest that the enhanced xanthine oxidase activity and depleting glutathione content in comthyroid treated rats result in pathophysiological oxidative stress including an increment of hepatic lipid peroxidation.

• Archives of Pharmacal Research
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• v.21 no.1
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• pp.1-5
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• 1998

Rebamipide, 2-(4-chlorobenzoylamino)-3-[2(1H)-quinolinone-4-yl]-propionic acid, a novel antipeptic ulcer agent, has been reported to prevent various acute experimental gastric mucosal lesions and to accelerate the healing of chronic ulcers. Therapeutic effect of rebamipide was investigated with regard to the inhibitory effect on xanthine oxidase activity and type conversion of the enzyme which play a profound role in oxygen radicals generation system. Intraperitoneal administration of rebamipide at 60 mg/kg body weight reduced the xanthine oxidase activity, lipid peroxide content in ammonia induced hemorrhagic lesion. These results suggest that the therapeutic effect of rebamipide on gastric mucosal lesion may be in part due to the inhibitory activity of xanthine oxidase and type conversion rate of the enzyme.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.192-204
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• 1996

Cervus elaphus for herb-acupuncture solution (CEHAS) was tested for the effects of free radical generating enzyme and lipid peroxidation in rat's kidney. In vitro, levels of lipid peroxide in tissues of kidney were proportionally decreased to concentration of extracts prepared from CEHAS. They were much more decreased, when lipid peroxidation was induced with ferrous iron (FeII). Also, enzyme activities of xinthine oxidase were decreased. The ratio of type conversion of xanthine oxidase was lowered, two. But, it was not seen changes on enzyme activities of aldehyde oxidase. These results suggest that CEHAS decrease the activities of free radical generating enzymes such as xanthine oxidase which form lipid peroxide.

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.335-337
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• 1992

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.167-180
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• 1999

Cervus elaphus, being known to reinforce Kidney, have tested to study the effects concerning damages of brain tissue induced by lipid peroxidation. In vitro, the level of lipid peroxide in brain tissue was decreased proportinally according to dose by Cervus elaphus extract solution for aqua-acupuncture (CESAA). It was much more decreased, when lipid peroxidation was induced with Fe(II). And, it was seen proportinally decrease according to the dose of CESAA on xanthine oxidase activities and type conversion ratio. However, I can not find special changes about aldehyde oxidase activities. And, I had observed the effects of CESAA on damages of rat's brain following ischemia and reflow. Before ischemia was caused, CESAA was applied 0.2 ml per 250 g through femoral vein in ischemia and reflow group and normal sailine was applied in normal group. Ischemia was caused by cervical artery's clamp for 30 min and reflowed by clamp remove after 15 min. It was increased on the content of lipid peroxidation, activies and type conversion ratio of xanthine oxidase following ischemia and reflow. However, they were decreased when CESAA was pre-appllied. However, it could not seen special changes on aldehyde oxidase activities, either. In conclusion. CESAA recovers the damage of brain due to ischemia and reflow by decreasing the lipid peroxidation through decreasing of xanthine oxidase activies and type conversion ratio.

• Advances in Traditional Medicine
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• v.7 no.5
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• pp.477-484
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• 2008

The present study was aimed at investigating the hypouricemic and xanthine oxidase inhibitory activities of the various fractions of the hydromethanolic extract of the leaves of Coccinia grandis L. Voigt (Cucurbitaceae). The leaves of this species was used in traditional medicinal system for the treatment of gout, rheumatism, jaundice, bronchitis, fever, skin eruptions, wounds, etc. The degree of xanthine oxidase inhibition was determined in vitro by measuring the increase in absorbance at 295 nm associated with uric acid formation. Among the fractions tested, the chloroform fraction exhibited highest potency ($IC_{50}$ $17.8\;{\mu}g/ml$). This was followed by the pet-ether ($IC_{50}$ $29.7\;{\mu}g/ml$), ethyl acetate ($IC_{50}$ $41.2\;{\mu}g/ml$) and residual ($IC_{50}$ $47\;{\mu}g/ml$) fractions. The $IC_{50}$ value of allopurinol was $6.1\;{\mu}g/ml$. In addition, the hypouricemic and hepatic xanthine oxidase (XO)/xanthine dehydrogenase (XDH) inhibitory activities of the fractions were examined in vivo using oxonate (280 mg/kg, i.p.) induced hyperuricemic mice. At a dose of 200 mg/kg orally for 7 days, the pet-ether, chloroform and ethyl acetate fractions produced a significant (P < 0.01) reduction in serum urate level and also inhibited hepatic XO/XDH activities when compared to hyperuricemic mice. These inhibitory effects were weaker than that observed for the standard drug, allopurinol (10 mg/kg, p.o.). Lineweaver-Burk analysis of the enzyme kinetics indicated that the mode of inhibition was of a mixed type. These results suggest that the use of Coccinia grandis leaves for the treatment of gout could be attributed to its XO inhibitory activity.

• Analytical Science and Technology
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• v.36 no.1
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• pp.44-52
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• 2023

This protocol clarifies a simple and precise method for measuring the activity of xanthine oxidase (XO) enzyme inhibitor. XO enzyme, which accelerates oxidative stress-related disorders through its capacity to generate hydrogen peroxide and superoxide anion radicals (O₂^•-), has been found to be inhibited by several plant extracts. Enzyme samples were incubated with a suitable buffer containing adequate amounts of xanthine as a substrate to determine XO activity. The method depends on direct measurements of uric acid and hydrogen peroxide production to test XO with and without interference. The CUPRAC reagent (Cu(Nc)₂²⁺) was used to inhibit enzyme reaction after incubation was complete. The generated urate and peroxide reduced the Cu(II)-neocuproine complex (Cu(Nc)₂²⁺) to a brightly colored Cu(I)-neocuproine complex (Cu(Nc)₂⁺), which was assessed with a spectrophotometer at 450 nm. XO activity was found to be directly related to the increased absorbance of the colored Cu(I)-neocuproine complex (Cu(Nc)₂⁺). To eliminate catalase enzyme interference, the proposed method used sodium azide and was validated against XO activity using the UV method in matched samples with t-test analysis. The proposed assay can determine XO activity with high precision, as indicated by the correlation coefficient (R² = 0.9935) from comparison with the reference protocol.

• Journal of Environmental Health Sciences
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• v.16 no.1
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• pp.67-74
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• 1990

An effect of carbon tetrachloride (CCl$_{4}$) was studied on the xanthine oxidase(XOD)activity of small intestine in male rats. Concomitantly a cause of increasing small intestine XOD was focused on an effect of actinomycin D and the kinetics of partial purified XOD frdm small intestine in CCl$_{4}$ intoxicated rats. An injection of CCl$_{4}$ to the rats showed an increase of small intestine XOD. In the pretreatment of actinomycin D before injection of CCl$_{4}$ to the rats, the XOD activities of small intestine were significantly decreased. In the partial purified enzyme preparation, the small intestine XOD in CCl$_{4}$ intoxicated rats showed the more increased Km and Vmax value with xanthine as substrate than that of control group.