• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.3
• /
• pp.209-213
• /
• 1991

To evaluate the effect of methanethiol on the activity of xanthine oxidase in both liver and serum, the rats intraperitoneally received methoanethiol. Injection of methoanethiol in rats showed the more decreased xanthine oxidase activity of boty liver and serum than that of the control group. Concomitantly, the xanthine oxidase activity in livers preincubated with methanethiol was decreased in vitro. The xanthine oxidase in livers preincubated with the methoanethiol also showed more increased Km and similar Vmax value than those of the control. These results suggest that the methanethiol may induce a change in substrate binding affinity of xanthine oxidase.

• Korean Journal of Animal Reproduction
• /
• v.25 no.3
• /
• pp.243-250
• /
• 2001

The objectives of the present study were to examine the relationship between catalase (0.1 mg/$m\ell$) and xanthine (5 mM) on in vitro maturation of porcine follicular oocytes. At 48 h after maturation, the proportions of oocytes matured to metaphase-II stage were significantly higher (P＜0.05) in the medium with control (72%), catalase (73%) or catalase plus xanthine (70%) than of oocytes cultured with xanthine (54%). On the other hand, oocytes cultured in medium with catalase and/or xanthine for 30 h were not significantly different in maturation rates (6~l4%). At 36, 42 and 48 h after culture, however, the maturation rates were significantly (P＜0.05) higher in medium with (49~70%) that than without (29~50%) catalase regardless of presence of xanthine. When the oocytes were cultured with periods prolonged in medium with and without xanthine, the maturation rates did increase with high proportions at 72 h of culture. No significant differences, however, were observed in maturation rates between groups with and without catalase. On the other hand, degenerated oocytes were increased with culture periods, the proportions was significantly (P＜0.05) lower in medium with (28%) than without (47%) catalase at 120 h of culture. However, there were no significant difffrences between with and without catalase in medium added xanthine. The parthenogenetic oocytes were observed from 72 h after culture in medium with xanthine, but were no significant differences between with and without catalase. From these results, it is indicated that porcine oocytes nay respond to maturation stimulus by 72 h of culture in medium with catalase and xanthine and that parthenogenesis can be obtained with prolonged culture periods.

• Clinical and Experimental Reproductive Medicine
• /
• v.25 no.3
• /
• pp.315-322
• /
• 1998

The objective of this study was to test the effect of catalase on penetration in vitro by spermatozoa preincubated with xanthine and/or xanthine oxidase. The penetration rates were, significantly (p<0.05) higher in spermatozoa preincubated without (66 and 38%) than with (40 and 15%) catalase for 0 and 30 min. When spermatozoa were preincubated and inseminated in medium with xanthine, the penetration rates were significantly higher (p<0.05) in medium with (68, 70 and 49% for 0, 30 and 60 min) than without (33, 41 and 19% for 0, 30 and 60 min) catalase. However, in oocytes were' inseminated with spermatozoa pre incubated with or without catalase in the presence of xanthine oxidase, no decrease in penetrations rates were observed for up to 60 min of preincubation. In another experiment, the penetration rates were significantly (p<0.00l) higher in medium with (75, 55 and 52%) than without (14, 4 and 8%) catalase when oocytes were inseminated with spermatozoa preincubated for 0, 30 and 60 min in the presence of xanthine plus xanthine oxidase. On the other hand, The rate of polyspermy in oocytes penetrated in medium without catalase in the presence of xanthine or xanthine plus xanthine oxidase decreased with time of spermatozoa preincubation. However, no differences were observed in polyspermy rates in the medium with xanthine oxidase alone despite presence of catalase. These results indicate the advantages of spermatozoa pre incubated with xanthine plus xanthine oxidase in the presence of catalase to increase penetration potential and with suppressed polyspermy in porcine.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.4
• /
• pp.693-697
• /
• 1998

The influence of flavonols from onion skin on xanthine oxidase was investigated. Methanol extract was showed 12.8% of yield, 661.3mg% of flavonoids contents and 88.7% of inhibitory effect on xanthine oxidase F1 and F2 fractions were obtained from the methanol extract by ODS and Sephadex LH-20 chromatography. F1 and F2 fractions flavonols(3-OH free) identified by UV/visible spectroscopy. Inhibitory effect of F1 and F2 on xanthine oxidase were increased with increasing concentration. IC50s of F1 and F2 were 0.95$\mu\textrm{g}$ and 0.67$\mu\textrm{g}$, respectively. To confirm the specificity of F1 and F2 against xanthine oxidase, albumin was added to the reaction mixture. The inhibition of F1 and F2 may be due to specific binding to xanthine oxidase. The modes of their inhibitions were of mixed type with respect to xanthine as a substrate.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.4
• /
• pp.418-422
• /
• 1993

For the purpose of utilizing tannins in the functional foods and crude drugs the xanthine oxidase inhibition of tannins isolated from Korean green tea was determined. Acetone extract from Korean green tea showed inhibitory effect against the xanthine oxidase. The galloyl tannins showed higher inhibitory activity against xanthine oxidase than the nongalloyl tannins. In terms of stereo isomers, (-)-epicatechins had higher inhibitory activity than the (+)-catechins. The synergistic activity was also observed. Tannins isolated from Korean green tea appeared to be incompetitive inhibitor against the xanthine oxidase.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.6
• /
• pp.1069-1073
• /
• 1996

Inhibition of xanthine oxidase by seaweed extracts obtained from Undaria pinnatifida, Ecklonia stolonifera, Ecklonia cava, Laminaria japonica, Sargassum, Codiumfragile, Enteromorpha compressa and Porphyra tenera were investigated. Extracts of E. stolonifera and E. mua remarkably inhibited xanthine oxidase activity compared to those of other seaweed. The xanthine oxidase inhibitory activity of E. cava was higher than that of E. stolonifera. Diethyl ether extract from E. cava was more effective in the inhibition of xanthine oxidase than other solvent extracts. Two xanthine oxidase inhibitors(A-1 and A-2) from diethyl ether extract were isolated and purified by silica gel column chromatography, thin layer chromatography and high performance liquid chromatography. Xanthine oxidase inhibitory activities of these compounds were 27.8 and 48.1% per 0.4mg, respectively. The active compound A-2 had absorption peak at 420nm, 456nm and 467nm, which can be considered as siphonaxanthine.

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

• The Korean Journal of Food And Nutrition
• /
• v.14 no.2
• /
• pp.120-125
• /
• 2001

The inhibitory effects of xanthine oxidase by the methanol extract and the solvent fractions obtained from persimmon leaves were investigated. The inhibition ratio of xanthine oxidase was 78% by addition of 2.0mg/ml of the methanol extract. Among the solvent fractions, the ethylacetate fraction showed the strongest inhibitory effect against the xanthine oxidase, followed by the hexane fraction. The effect increased with addition of the ethylacetate fraction. At a concentration of 2.0mg/ml of the ethylacetate fraction, 65% of the enzyme activity decreased within 1.0 min of incubation with xanthine oxidase. But the activity of xanthine oxidise did not decrease significantly by the length of the incubation time.

• Applied Biological Chemistry
• /
• v.21 no.2
• /
• pp.112-118
• /
• 1978

Xanthine oxidase from bovine thyroid glands was purified to apparent homogeneity when judged by analytical disc gel electrophoresis. The purification procedures include pancreatin digestion, butanol extraction, ammonium sulfate precipitation, calcium phosphate gel adsorption, ultrafiltration, calcium phosphate gel-cellulose column chromatography, gel filtration, preparative Sephadex G-25 column electrophoresis, and preparative polyacrylamide gel electrophoresis. The enzyme was enriched 1,000-fold. However, its specific activity was markedly low as compared with highly purified milk enzyme. Thyroidal xanthine oxidase exhibited a low specificity for substrates and electron acceptors. The kinetic properties of thyroid xanthine oxidase were found to be similar to those of the milk enzyme on the basis of Michaelis constants for common substrates.

• Journal of Applied Biological Chemistry
• /
• v.62 no.3
• /
• pp.275-280
• /
• 2019

This study was performed to certify the inhibitory effect of aqueous extracts from sixty-seven medicinal plants on the activity of xanthine oxidase in vitro. Among the sixty-seven medicinal plants, Scutellaria baicalensis Georgi, Citrus aurantium L., Polygonum multiflorum Thunb., Pueraria thunbergiana (Sieb. et Zucc.) Benth., Citrus unshiu Marcor., Rubus coreanus Miquel, Camellia sinensis L., and Poncirus trifoliata Raf. were regarded as effective anti-gout sources. The active substances of P. multiflorum root extract were very stable at pH 2.0 and high temperatures. Xanthine oxidase activity was proportionally inhibited when concentrations of P. multiflorum extract increased. The aqueous extract from P. multiflorum root at a concentration of 2.0 mg/0.1 mL inhibited xanthine oxidase by 73.8%.