• Applied Biological Chemistry
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• v.38 no.6
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• pp.590-595
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• 1995

To examine the characteristics of antioxidative compounds from Capsella bursa-pastoris, ethanol extracts were separated into five organic solvent fractions; hexane(Fr.H), diethyl ether (Fr.E), ethyl acetate(Fr.EA), butanol (Fr.B), and water(Fr.D) fractions. Fr.B showed the greatest electron donating ability and inhibitory effect on lipid peroxidation. Whereas Fr.E had the most excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. The inhibitory effect of each fraction on xanthine oxidase was also measured. Fr.E had the strongest inhibitory effect on xanthine oxidase and $IC_{50}$ was $5.65\;{\mu}g$. The results indicate that the superoxide radical scavenging activity of Fr.E is caused by the inhibitory effect on radical generating system of xanthine oxidase. Also the order of inhibitory effect on xanthine oxidase was Fr.B

• YAKHAK HOEJI
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• v.38 no.2
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• pp.211-217
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• 1994

Copper intoxication and disturbance of copper metabolism induced various oxygen-derived free radicals related damages. The effect of copper ion on xanthine oxidase activity and type conversion of the enzyme which is concerned to generation of reactive oxygen species, was investigated, It was observed that xanthine oxidase activity was increased by addition of copper ion in the reaction mixture in proportional to the concentration of the metal ion until $60\;{\mu}M$, while the enzyme activity was inhibited in higher concentration of copper treatment. On the other hand, xanthine dehydrogenase activity was inhibited by copper ion addition with concentration dependently. Preincubation of enzyme source with $30\;{\mu}M$ of copper ion, which concentration marked increased the xanthine oxidase activity, unchanged the enzyme activity and type conversion compare to control in vitro system. It was also observed that copper induced xanthine oxidase activity and the enzyme type conversion was protected by dithiothreitol and penicillamine. These results indicate that the increment of the type conversion of xanthine oxidase necessarilly need the presence of copper ion in enzyme assay system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.527-537
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• 1991

To evaluate an effect of liver xanthine oxidase on the induction of liver damage, carbon tetrachloride (CCl4) was intraperitoneally injected twice at 0.1ml/100g body weight to the rate fed a low (LP)or high protein diet(HP) while the control group fed LP or HP received only olive oil. The changing rate of liver xanthine oxidas activity was compared with that of a free radical generating enzyme, liver aniline hydroxylase and a scavenging enzyme, glutathions S-transferase activity between the rate fed a LP and those fed HP, and the two groups treated with CCl4. Concomitantly, the degree of liver damage which could be considered as the paramete for CCl4 metabolism in case of CCl4-intoxicated animal was observed in the present experimental conditions and the effect of allopurinol, xanthine oxidase inhibitor, on the CCl4-toxicity of rate liver was alos demostrated. On the other hand, the comparative effect of actinomycin D on the liver and serum xanthine oxidase of CCl4-treated rats fed HP with that of those fed LP and the kinetics of purifed liver enzyme from the liver of CCl4-treated rats fed HP was also compared with that of those fed LP to clarify the differences of xanthine oxidase activity between two groups. The increasing rate of liver weigth/body wt, serum levels of ALT and the decreasing rate of hepatic ALT activity and protein contents to each control group were higher in CCl4-treated rats fed HP than those fed LP. Under the animal models as indentified by the present data herein, the liver xanthine oxidase activity was higher in CCl4-treated rats fed HP than those fed LP, and the control group fed HP also showed the much higher activity xanthine oxidase than that fed LP, whereas there were no differences in the activity of hepatic aniline hydroxylase and glutathions S-transferase between the two group treated with CCl4. Although the hepatic aniline hydroxylase activity was somewhat higher in the rats fed HP than those fed LP, the increasing rate of liver xanthine oxidase to the rats fed LP was higher in those fed HP than that of liver aniline hydroxylase. The degree of liver damage identified such as liver weight and serum ALT activity was less in the CCl4-treated rats pretreated with allopurinol. These results suggest that even a system at which xanthine oxidase acts as well as the drug metabolizing enzyme may influence the acelatin of CCl4 metabolism. In addition, the purified liver xanthine oxidase from CCl4-treated rats fed HP showed decreased Km value when compared to its control group. The Km value of liver xanthine oxidase of CCl4-treated rats fed LP showed a similar Km value with its control group. Furthermore, the decreasing rate of liver and serum xanthine oxidase acitivity in CCl4-treated rats pretreated with actinomycin D to the CCl4-treated rats was higher in rats fed HP than in those fed LP. These results suggest that the inductino of xanthine oxidase in CCl4-treated rats fed HP may be greater than in those fed LP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.411-416
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• 1997

To examine the free radical scavenging activities from buckwheat, Suwon No. 5 was extracted with various solvents. The seed of Suwon No. 5 had a high contents of carbohydrate, but the vegetable of that had a 31.4% of protein, 28.6% of ash and 25.7% carbohydrate as moisture free basis. Phenols contents of vegetable extracts had higher than those of seed extracts. Acetone extract of vegetable showed the greatest electron donating ability. Butanol and acetone extracts of vegetable showed high inhibitory effect on lipid peroxidation. Acetone extract of vegetable has also excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. The inhibitory effects of extracts on xanthine oxidase were measured. Acetone extract had the strongest inhibitory effect on xanthine oxidase and $IC_{50}$ was 2.2$\mu\textrm{g}$.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.74-74
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• 2002

This study was undertaken to evaluate the effects of β-mercaptoethanol on lipid peroxidation and fertilization ability in vitro by xanthine (X)-xanthine oxidase (XO) system in boar spermatozoa frozen-thawed. When spermatozoa were inseminated in medium with X and/or XO, the penetration rates in all conditions were higher in medium with that than without β-mercaptoethanol. However, significant differences were not observed between medium with and without β-mercaptoethanol. The lipid peroxidation of sperm was evaluated on the basis of malondialdehyde (MDA) production. (omitted)

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.69-77
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• 1993

In the present study, the comparison of liver damage in carbon tetrachloride (CCl$_4$)-treated rats with that those pretreated with ethanol and an effect of liver injury on the serum and liver xanthine oxidase (XOD) activity were evaluated. The increasing rate of liver weight per body wt., the levels of serum alanine aminotransferase, and the decreasing rate of hepatic glucose-6-phosphatase activity and the protein contents in the liver cell were higher in carbon tetrachloride-treated animals pretreated with ethanol than the carbon tetrachloride-treated group. Especially, the histopathological findings also showed more severe liver damage in the ethanol-pretreated rats than the rats treated with carbon tetrachloride only. In such a experimental condition the xanthine oxidase activity of serum and liver both of carbon tetrachloride-treated rats and those pretreated with ethanol were higher than that of each control group. And the increasing rate of xanthine oxidase enzyme activity to the control group was higher in carbon tetrachloride-treated group pretreated with ethanol than those treated with CCl$_4$. In addition, the heptic uricase activity and the serum levels of uric acid were more increased in carbon tetrachloride-treated group pretreated with ethanol than those in the CCl$_4$-treated rats. On the other hand, there were no statistical differences in hepatic catalase and glutathione S-transferase activities between the CCl$_4$-treated rats and those pretreated with ethanol. In conclusion, it is assumed that the more severe liver damage in ethanol pretreated rats would be due to oxygen free radical produced by the xanthine oxidase system.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.254-258
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• 1997

To examine the characteristics of the antioxidative property of Buckwheat components, acetone extracts from a buckwheat, Suwon 5, was fractionated using five solvents. Hexane, ethylacetate, ether, butanol and water fractions were obtained. Butanol fraction showed the greatest electron donating ability and inhibitory effect on lipid peroxidation. It also showed the most excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. Spectrophotogram of butanol fraction was similar to that of rutin. Superoxide radical scavenging activity was related to the contents of rutin. Inhibitory effect of each fraction on xanthine oxidase was also measured. Butanol fraction had the strongest inhibitory effect on xanthine oxidase and $IC_{50}\;was\;3.1\;{\mu}g$. The inhibition type of butanol fraction on xanthine oxidase turned out to be a mixture of the uncompetitive and non-competitive modes.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.678-684
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• 1993

To evaluate the role of xanthine oxidase in liver damage by CCl4, a group of rats were fed tungstate for a month, which suppressed the activities of xanthine oxidase in serum and liver. Control group of rats were fed standard diet without tungstate. Liver damage was induced both in tungstate fed and control groups by two intraperitoneal injections of CCl4 at the level of 0.1ml/100g body weight at intervals of 24 hours. Increases in the levels of serum alanine aminotransferase by CCl4 were significantly smaller in tungstate fed rats than in control rats. Concomitantly, histopathologic changes were less in tungstate fed rats than in control ones. In rats either treated with CCl4 or not, hepatic type O xanthine oxidase activities were remarkably reduced by tungstate feeding. Hepatic aniline hydroxylase activities were higher in rats fed tungstate than control rats when animals were not treated with CCl4, but the enzyme activities were lower in tungstate fed rats than control when they were treated with CCl4. Neither tungstate feeding nor CCl4 treatment caused any significant changes in hepatic glutathione contents, and activities of hepatic glutathione S-transferase, glutathione peroxidase and superoxide dismutase. It is concluded xanthine oxidase reaction augment CCl4 induced liver damage via oxygen free radical system.