• 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.

• Preventive Nutrition and Food Science
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• v.11 no.3
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• pp.198-203
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• 2006

The flowers of Chrysanthemum morifolium (Compositae) were investigated for their biofunctional components. Antioxidant compounds were identified from the flower of Chrysanthemum morifolium, through activity-guided fractionation and repeated column chromatographic separations. The structures of the isolated compounds were characterized as chlorogenic acid (1), luteolin (2) and quercitrin (3) by the analysis of physico-chemical and spectral data. Their antioxidant effects were evaluated by assaying for 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity and inhibition of xanthine/xanthine oxidase activity.

• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.31-39
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• 2003

The antioxidative activities and biological properties in the EtOAc extracts and purified extracts of Orostachys japonicus were measured by assay of DPPH, xanthine/xanthine oxidase and mammalian cells(2-12). Scavenging of DPPH radical and inhibition of xanthine/xanthine oxidase of EtOAc extracts were showed the highest activity in the arable land and in September. The S-4 fraction showed the highest activity among the silica-gel column chromatography fractions. LH-4 fraction showed higher activity than the other fractionsins in assay of DPPH and xanthine/xanthine oxidase. Fatty acids and phenolic compounds were identified by GC/MS and main compounds were 1,2,3-benzenetriol, alpha-androsta-7,14-diene in LH-4 fraction. The activities of POD and SOD in samples havested on different habitats were high such as arable land> intermountain> seashore. That of POD and SOD in crude extracts of late stage were higher than early stage. Isozyme bands of crude extracts samplinged in all habitats and all growing stages showed two bands and the signal intensity showed strongly according to passage of growing stage. The purified extracts of LH-4 fraction showed excellent inhibition effect in proliferation of HL-60 cells and markedly suppressed colony formation in mouse fibroblast cells. Dose response between partially purified extracts(400ppm) and negative control did not produced statistically significant reduction in colony formation.

• Journal of Life Science
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• v.13 no.1
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• pp.1-8
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• 2003

Antioxidant activity and biological properties in the MeOH extracts from different plant parts of Euonymus alatus (THNUB.) were measured by DPPH free radical scavenging ability and inhibition ability against xanthine/xanthine oxidase and proliferation in HL-60 cells. DPPH free radical scavenging activities in extracts of plant parts were high such as leaf, wing, root, seed and stem, respectively. The EtOAc fractions of plant parts were purified through LH-20 column chromatography and identified by GC/MS. LH-4 fraction and LH-5 fraction of leaf, stem and root showed stronger activities than other fractions in the inhibitor activity of DPPH and xanthine/ xanthine oxidase. $IC_{50}$ values of LH-4 fraction eluted from stem extracts showed such as 2.38 and 5.32 in DPPH and xanthine/ xanthine oxidase assay. Polyphenolic compounds were identified in purified LH-20 fractions showed highest $IC_{50}$ value in DPPH and xanthine/xanthine oxidase assay The activity of POD according to sampling time was high in root harvested in May and leaf harvested in September, respectively. The activity of SOD showed only in the extracts of stem in plant parts. SOD and POD in leaf were similar in the patterns of isozyme to those of stem. The purified extracts from Euonymus alatus (THNUB.) exerted inhibition ability of proliferation in HL-60 cells.

• The Journal of Korean Medicine
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• v.20 no.4
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• pp.3-10
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• 2000

In order to elucidate the toxic mechanism of neurotoxical damage and neuroprotective effect of Jangwon-hwan(Zhuangyuan-wan) water extract, this experiment was performed. Neurotoxic effects of xanthine oxidase/hypoxanthine(XO/HX) were examined by MTT and NR assay, neuroprotective effects of Jangwon-hwan(Zhuangyuan-wan) water extract were examined by neurofilament enzymeimmuno assay(EIA). XO/HX induced an increase in cell viability, and a decrease in the amount of neurofilament on cultured mouse cerebral cortical neurons in dose-dependent manner. In neuroprotective effect of herb medicine, Jangwon-hwan(Zhuangyuan-wan) water extract increased the amount of neurofilament on cultured mouse cerebral cortical neurons damaged by XO/HX. From the results, it is suggested that XO/HX showed toxic effect in cultured mouse cerebral cortical Neurons and Jangwon-hwan(Zhuangyuan-wan) water extract is very effective in the prevention of neurotoxicity induced by XO/HX.

• The Journal of Korean Medicine
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• v.21 no.1
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• pp.29-39
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• 2000

In order to elucidate the toxic mechanism of oxygen radicals in cultured mouse spinal sensory neurons, cytotoxic effect of oxygen radicals was evaluated by M1T assay and NR assay. In addition, protective effect of Sopunghwalhyultang(SPHHT) water extract on oxidant-induced neurotoxicity was investigated on these cultures. Spinal sensory neurons derived from mice were cultured in mediums containing various concentrations of Xanthine Oxidase / Hypoxanthine(XO/HX). Cell viability was measured by MTT assay and NR assay. XO/HX-mediated oxygen radicals remarkably decreased cell viability of cultured spinal sensory neurons in a dose-and time-dependent manner. And also, SPHHT blocked XO/HX-induced neurotoxicity in these cultures. These results suggest that oxygen radicals are toxic and SPHHT are effective in blocking against the oxidant-induced neurotoxicity in cultures of spinal sensory neurons of mice.

• Natural Product Sciences
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• v.5 no.4
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• pp.165-171
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• 1999

Since reactive oxygen species (ROS) play an important role in carcinogenesis and other several human diseases, antioxidants present in consumable fruits, vegetables, and beverages have received considerable attention as cancer chemopreventive agents. Thus, in order to identify antioxidants in plant extracts, potential activity was assessed by determining with inhibition of a xanthine/xanthine oxidase assay system. Approximately 170 plant extracts of Korean herbal medicines were primarily evaluated for the potential of antioxidant activity. As a result, 13 plant extracts were found to be active $(IC_{50}$<$100\;{\mu}g/ml)$. Especially, Juncus effusus, Selaginella tamariscina, Pueraria thunbergiana and Sedum albroseum showed strong inhibitory activity in this process. Further studies for the identification of active principles from these active lead plant extracts might be warranted.

• Herbal Formula Science
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• v.8 no.1
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• pp.319-328
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• 2000

To evaluate the effect of Baepungtang(BPT) water extract on cultured mouse spinal sensory neuron which was inhibited by xanthine oxidase(XO) and hypoxanthine(HX)-induced oxigen radicals, MTT assay, NR assay, Neurofilament enzymeimmuno assay and LDH activity assay were carried out after the cultured mouse spinal sensory neuron were preincubated with various concentrations of BPT water extract for 3 hours prior to exposure of XO/HX. The results obtained were as follows: 1. XO/HX, a oxigen radical, decreased the survival rate of the cultured mouse spinal sensory neuron cell on NR assay and MTT assay. 2. $MTT_{50}$ value and $NR_{50}$ value of XO/HX were 30 mU/ml XO/O.2 mM HX. 3. BPT water extract have efficacy of increasing neurofilament. 4. BPT water extract have efficacy of increasing LDH activity. From above the results, It is concluded that BPT has marked efficacy as a treatment for the damages caused in the XO/HX-mediated oxidative process.

• 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.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.208-214
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• 2012

Chaff-vinegar is known for having a variety of useful purposes in the fields of health and lifestyles. In a previous study we isolated and identified the active fractions of the polyphenol compound 7 species as a potential biomaterial for cosmeceuticals. To further test for its potential use as a functional material, we carried out an MTT assay, collagenase inhibition assay, elastase inhibition assay, tyrosinase inhibition assay, DPPH free radical scavenging assay, SOD-like activity assay and a xanthine oxidase inhibition assay. Chaff-vinegar exhibited potent collagenase and elastase inhibitory activities in a concentration dependent manner, indicating that the agent has the potential to alleviate the skin wrinkling process. Chaff-vinegar also showed 80% tyrosinase inhibition at a concentration of $100{\mu}L/mL$. DPPH radical scavenging, xanthine oxidase inhibition, and SOD-like activity results for each activity were 80%, 80%, and 100%, respectively. Taken together, the present study suggests that chaff-vinegar is a good candidate for use as an anti-wrinkling and/or whitening agent.