• Korean Journal of Oriental Medicine
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• v.5 no.1
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• pp.111-117
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• 1999

Free radicals are thought to be the most important cause of the reperfusion injury subsequent to ischemia. The antioxidant status of the tissue affected by ischemia-reperfusion is of great importance for the primary endogenous defense against the free radical induced injury. Therefore, antioxidant therapy has been shown to be beneficial in neurological disorders such as Alzheimer's disease and cerebral ischemia. In this study, the protective effects of Chungpesagan-tang (CST) was investigated against ischemia/reperfusion-induced cytotoxicity in SK-N-MC neuronal cells It was found out that low concentration of CST was highly effective in protecting neuronal cells against ischemia/reperfusion-induced cytotoxicity. The inhibitory effect of CST on malondialdehyde formation during ischemia/reperfusion-induced oxidative stress in SK-N-MC cells showed obvious dose-dependent responses. Also, CST showed relatively high inhibitory activity to xanthine oxidase induced by ischemia/reperfusion environment Therefore, it is thought that CST has both antioxidant and xanthine oxidase inhibitory effect and can be used for clinical applications for protection of neuronal cells from ischemia-reperfusion injury.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1309-1314
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• 2006

This study analyzed the contents of vitamin C, polyphenol compounds, and evaluated the inhibitory activities against xanthine oxidase and tyrosinase of Lepista nuda extract prepared by the reflux and microwave-assisted methods. The vitamin C content of the fresh L. nude was $9.92{\pm}0.02$ mg/100 g. The content of phenolic compounds in the fresh L. nuda was $1.87{\pm}0.02\;mg/g$. The ethanol extracts prepared by reflux method and microwave-assisted method showed the highest phenol contents of $12.06{\pm}0.12\;mg/g\;and\;11.84{\pm}0.17\;mg/g$, respectively. The inhibitory rates on xanthine oxidase and tyrosinase of ethanol extracts prepared by the microwave assisted method showed the highest value of 99.78% and 30.30% at the concentration of $3,000{\mu}g/mL$. The inhibitory activities on xanthine oxidase and tyrosinase were increased depending on the extract concentration.

• The Korean Journal of Mycology
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• v.43 no.1
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• pp.47-52
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• 2015

Several kinds of yeasts were isolated from wild flowers collected from Muju resort of Deogyu mountain in Korea and identified by comparison of nucleotide sequences of D1/D2 region of 26S rDNA using BLAST. Totally twenty-two strains of eight species were isolated and Cryptococcus magnus (9 strains) and Cryptococcus flavescenes (6 strains) were dominant species. The supernatant and cell-free extracts were prepared and their antioxidant activity, anti-gout xanthine oxidase inhibitory activity and whitening tyrosinase inhibitory activity were investigated. Anti-gout xanthine oxidase inhibitory activities of Sporobolomyces phaffii JS00583 and Rhodotorula graminis JS00581 were 40.4% and 39.1%, respectively and also was 36.1% whitening tyrosinase inhibitory activity in the supernatant of Cryptococcus magnus JS00570.

• Mycobiology
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• v.39 no.1
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• pp.12-19
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• 2011

Cellular damage caused by reactive oxygen species has been implicated in several diseases, thus establishing a significant role for antioxidants in maintaining human health. Acetone, methanol, and hot water extracts of Pleurotus citrinopileatus were evaluated for their antioxidant activities against ${\beta}$-carotene-linoleic acid and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, reducing power, ferrous ion-chelating abilities, and xanthine oxidase inhibitory activities. In addition, the tyrosinase inhibitory effects and phenolic compound contents of the extracts were also analyzed. Methanol and acetone extracts of P. citrinopileatus showed stronger inhibition of ${\beta}$-carotene-linoleic acid compared to the hot water extract. Methanol extract (8 mg/mL) showed a significantly high reducing power of 2.92 compared to the other extracts. The hot water extract was more effective than the acetone and methanole extracts for scavenging DPPH radicals. The strongest chelating effect (92.72%) was obtained with 1.0 mg/mL of acetone extract. High performance liquid chromatography analysis detected eight phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, naringenin, hesperetin, formononetin, and biochanin-A, in an acetonitrile and hydrochloric acid (5 : 1) solvent extract. Xanthine oxidase and tyrosinase inhibitory activities of the acetone, methanol, and hot water extracts increased with increasing concentration. This study suggests that fruiting bodies of P. citrinopileatus can potentially be used as a readily accessible source of natural antioxidants.

• Journal of Integrative Natural Science
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• v.8 no.4
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• pp.258-266
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• 2015

Xanthine Oxidase is an enzyme, which oxidizes hypoxanthine to xanthine, and xanthine to uric acid. It is widely distributed throughout various organs including the liver, gut, lung, kidney, heart, brain and plasma. It is involved in gout pathogenesis. In this study, we have performed Comparative Molecular Field Analysis (CoMFA) on a series of 2-(indol-5-yl) thiazole derivatives as xanthine oxidase (XO) inhibitors to identify the structural variations with their inhibitory activities. Ligand based CoMFA models were generated based on atom-by-atom matching alignment. In atom-by-atom matching, the bioactive conformation of highly active molecule 11 was generated using systematic search. Compounds were aligned using the bioactive conformation and it is used for model generation. Different CoMFA models were generated using different alignments and the best model yielded a cross-validated $q^2$ of 0.698 with five components and non-cross-validated correlation coefficient ($r^2$) of 0.992 with Fisher value as 236.431, and an estimated standard error of 0.068. The predictive ability of the best CoMFA models was found to be $r^2_{pred}$0.653. The CoMFA study revealed that the $R_3$ position of the structure is important in influencing the biological activity of the inhibitors. Electro positive groups and bulkier substituents in this position enhance the biological activity.

• Biomedical Science Letters
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• v.27 no.4
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• pp.277-282
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• 2021

Hydrocotyle is a genus of prostrate, perennial aquatic or semi-aquatic plants formerly classified in the family Apiaceae, now in the family Araliaceae. Lipoxygenases (LOX) are present in the human body and play an important role in the stimulation of inflammatory reactions. Ethanolic extracts of five Hydrocotyle species (H. ramiflora, H. maritima, H. nepalensis, H. sibthorpioides, and H. yabei) showed inhibition of 23.5~50.6% at 2.0 mg/mL. Their extracts showed LOX inhibition in half maximal effective concentration (EC₅₀) range 15.1~15.7 ㎍/mL. Hyaluronic acid is a glycosaminoglycan, a major component of the extracellular matrix Five extracts of these species inhibited less than 23.0% of Hyaluronidase (HAase) activity at a concentration of 2.0 mg/mL Xanthine oxidase (XO) is a form of xanthine oxidoreductase, a type of enzyme that generates reactive oxygen species. Five Hydrocotyle species were found to have inhibitory activity of XO at 2.0 mg/ml, with 65% having greater than 50% inhibition. H. ramiflora exhibited the highest activity with an inhibition of 80.0%. The results suggested that Lipoxygenases, Hyaluronidase, and Busan 47340, Republic of Korea from five Hydrocotyle species might be multifunctional and prevent the degradation of allergic reactions and inflammation.

• Natural Product Sciences
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• v.24 no.1
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• pp.59-65
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• 2018

An isoform of NADPH oxidase (NOX), NOX2 is a superoxide-generating enzyme involved in diverse pathophysiological events. Although its potential as a therapeutic target has been validated, there is no clinically available inhibitor. Herein, NOX2-inhibitory activity was screened with the constituents isolated from Schisandra chinensis, which has been reported to have antioxidant and reactive oxygen species (ROS)-scavenging effects. Among the partitions prepared from crude methanolic extract, a chloroform-soluble partition showed the highest NOX2-inhibitory activity in PLB-985 cell-based NOX2 assay. A total of twenty nine compounds (1 - 29) were identified from the chloroform fraction, including two first isolated compounds; dimethyl-malate (25) and 2-(2-hydroxyacetyl) furan (27) from this plants. Of these constituents, two compounds (gomisin T, and pregomisin) exhibited an NOX2-inhibitory effect with the $IC_{50}$ of $9.4{\pm}3.6$, and $62.9{\pm}11.3{\mu}M$, respectively. They are confirmed not to be nonspecific superoxide scavengers in a counter assay using a xanthine-xanthine oxidase system. These findings suggest the potential application of gomisin T (6) and other constituents of S. chinensis to inhibit NOX2.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.593-598
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• 1999

This study was designed to investigate the possible utilization of Zizyphus jujuba leaves as a source of functional ingredients. The physiological activity of different solvent fractions prepared from ethanol extract of Zizyphus jujuba leaves were analyzed. Xanthine oxidase inhibitory effect was very high in all fractions except chloroform fraction. The very high electron donating ability was observed in the ethylacetate fraction and the effect was similar to 0.1% tocopherol. Nitrite scavenging effect of all fractions was more than 40% even at low concentration of 1mg/ml and was increased with increasing concentration. Angiotensin I converting enzyme inhibitory activity was appeared in ethyl acetate and chloroform fractions only at high concentraton.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.195-201
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• 2009

The antioxidative activities of two varieties of egg plant (Chunyang No 2: Dangaji, Jinju Janggaji: Janggaji) extracts were investigated. The total polyphenol contents of Dangaji peel hot water extract and the Janggaji flesh and fruit hot water extracts were higher than those of the other samples. However, the DPPH radical scavenging activities(electron donating activity) of Dangaji flesh-ethanol, peel-cold water, and fruit- ethanol extracts, as well as the Janggaji peel cold water extract, were higher than those of the other samples. Furthermore, the in vitro inhibitory effects of the Dangaji peel cold water and hot water extracts on rat hepatic xanthine oxidase were highest among the samples, and were exhibited in a dose dependant manners. Although there were marked changes in the xanthine oxidase Km values for xanthine as a substrate, the Vmax value changes by the addition of the Dangaji water extracts were minor compared with the control. This result suggests that Dangaji water extracts may regulate the activity of xanthine oxidase-via the inhibition of binding affinity between the enzyme and substrate. The present study provides experimental evidence that constituents of egg plant extracts may ameliorate reactive oxygen species(ROS)-induced oxidative stress via hepatic hepatic xanthine oxidase activity, but further studies to identify the active antioxidants and compounds and inhibitors of xanthine oxidase are required.