• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.6-10
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• 2005

Free radical-scavenging activities of Korean Bulro Kugi (Lycium chinense Mill) fruit, leaf, and root were evaluated. Total phenolic contents of fruit, leaf, and root were $1,078.4{\pm}61.0$, $939.9{\pm}19.8$, and $3,792.2{\pm}106.6mg/L$, and their flavonoids were $396.7{\pm}15.2$, $1,952.9{\pm}21.3$, and $425.3{\pm}13.5mg/L$, respectively (p<0.001). HPLC revealed main polyphenolic compounds in fruit were p-coumaric and syringic acids in fruit, p-coumaric, syringic, and procatechuic acids in leaf, and p-coumaric, syringic, caffeic, and procatechuic acids in root. Highest radical-scavenging activities of superoxide anion and hydroxyl were found in leaf and root, respectively (p<0.001).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4434-4442
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• 2011

Reactive oxygen species (ROS) are reactive and potentially harmful to cells, causing oxidation of lipids, proteins, and DNA. In humans, the deleterious effects of ROS have been linked with aging, carcinogenesis, and atherosclerosis. In order to investigate an antioxidant activity of wood vinegar by bioconversion, we preferentially analyzed the total acidity, acetic acid, pH, and contents of total polyphenols and flavonoids, respectively. Also, we evaluated the scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide anion radicals, hydrogen peroxide radicals, and nitric oxide radicals. The total acidity and amount of acetic acid of wood vinegar after bioconversion were lower than those of wood vinegar before bioconversion, but the pH was higher than that of wood vinegar before bioconversion. The contents of total polyphenols and flavonoids of wood vinegar after bioconversion were 11.17 mg/$m{\ell}$ and 0.42 mg/$m{\ell}$, respectively. The $SC_{50}$ values were in order of superoxide anion radical scavenging activity < DPPH radical scavenging activity < hydrogen peroxide radical scavenging activity < nitric oxide radical scavenging activity. Therefore, these results suggest that wood vinegar by bioconversion can be useful as primary antioxidants for medicines and cosmetics.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.761-767
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• 2018

Degenerative diseases are commonly associated with excess free radicals. Acer okamotoanum, a plant endemic to Korea, is reported to have anti-oxidant, anti-cancer, and anti-viral activities. We previously isolated flavonoids from the ethyl acetate fraction of A. okamotoanum such as quercitrin (QU), isoquercitrin (IQ), and afzelin (AF). In the present study, the in vitro antioxidant activity of flavonoids such as QU, IQ, and AF isolated from the ethyl acetate fraction of A. okamotoanum were investigated by measuring the free radical scavenging activity including 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\cdot}OH$), and superoxide anion ($O_2{^-}$). The flavonoids (QU, IQ, and AF) concentration-dependently showed a DPPH radical scavenging activity. In particular, QU and IQ showed a higher DPPH radical scavenging activity than that of AF. In addition, the flavonoids (QU, IQ, and AF) at $10{\mu}g/mL$ showed over an 80% scavenging effect against $^{\cdot}OH$ radical production. Furthermore, the $O_2{^-}$ radical scavenging activity of the flavonoids, QU, IQ, and AF increased in a dose-dependent manner. Particularly, IQ exerted the strongest scavenging activities against $^{\cdot}OH$ and $O_2{^-}$ radicals among the other flavonoids. These results indicate that the flavonoids from A. okamotoanum, in particular IQ, would have a protective activity against oxidative stress induced by free radicals, and potentially be considered as a natural antioxidant agent.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.157-163
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• 2012

Oxidative stress has been reported to be one of causes of neuritis. This study examined antioxidative activities of methanol extracts of six amphibian species known to be medicinal animals (Rana catesbeiana, R. coreana, R. rugosa, R. dybowskii, R. nigromaculata, and Hyla japonica) and investigated their effects of inhibiting nitric oxide (NO) production and cytotoxicity on the murine macrophage RAW264.7 cells. As inflammation is closely associated with reactive oxygen species, assays on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, xanthine oxidase inhibitory activity, superoxide anion radical scavenging activity and NO scavenging activity of the extracts of the six species were performed to investigate their antioxidative activity. The results obtained were as follows; All extracts showed antioxidative activity, and the activity of R. dybowskii was the highest in comparison among those. Anti-inflammatory effects of the extracts were also examined, the five extracts except that of R. rugosa did not show cytotoxicity for RAW264.7 cells at the maximal concentration ($1,000{\mu}g\;mL^{-1}$). Selectivity index, meaning NO scavenging activity compared to cytotoxicity, showed the highest level in the extract of R. dybowskii. These results will be very useful basic data for future studies on prevention and treatment of human diseases to understand the biological roles of amphibian extracts throughout the antioxidative or anti-inflammatory pathways.

• Biomedical Science Letters
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• v.14 no.1
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• pp.1-6
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• 2008

This investigation was performed to study the antioxidant activities and the antimicrobial effect of plum (Santarosa, Oishiwase) extracts. Plums were extracted by ultrasound-assisted method and boiling method. All extracts of plums showed concentration-dependent inhibitory effects on the DPPH free radical scavenging activity. In the superoxide anion radical scavenging method, all the plum extracts showed lower activity than BHT. But in case of sonicate extract of Oishwase exhibited the highest activity in plum extracts. The antimicrobial effect of plums used for human skin- or oral cavity-presented strains; Bacillus cereus (KCTC 1012) and Staphylococcus aureus (KCTC 1927). Addition of plum extracts was used by autoclaved and filtrated. Each extract solution was added into culture media with several concentration and then the bacteria cell growth was investigated for 72 hours. The effect of antimicrobial activities showed in a higher Staphylococcus aureus than Bacillus cereus. Results indicate that the autoclaved sample showed a higher antimicrobial activity than did the filtrated sample.

• Journal of the Korean Home Economics Association
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• v.42 no.5
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• pp.193-203
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• 2004

This study examined the changes in the chemical components and antioxidant activity of Ecklonia cava according to the drying methods. As chemical components, the concentrations of minerals(K, Ca, Na, Mg, Fe, Cu, Mn and Zn), vitamins(vitamin C, ${\beta}$-carotene and ${\alpha}$-tocopherol) and the total polyphenols were analyzed. In additions, the antioxidant activity was determined by measuring the free radical(DPPH radical, superoxide anion radical, hydroxyl radical and hydrogen peroxide) scavenging activity and the linoleic acid peroxidation inhibitory activity. The mineral content was not affected by the drying methods. However, more vitamins were lost and the total polyphenol concentration was reduced as a result of sun-drying than by the other drying methods used. More of the total polyphenol was preserved by freezing-drying than by any of the other drying methods, which meant that there was a higher antioxidant activity after freeze drying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.9
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• pp.1109-1113
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• 2008

The purpose of this study was to investigate the antioxidative and antiallergic effects of aronia extract. The aronia extract was tested for various antioxidative potentials (scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide anion radical) and inhibitory effect of 5-lipoxygenase (5-LO) and cyclooxygenase (COX). In aronia extract, polyphenol content was $81.6{\pm}3.3\;mg/g$ and flavonoid content was $5.15{\pm}0.16\;mg/g$. DPPH radical-scavenging activity ($SC_{50}$) of aronia extract was $6.15{\pm}0.343\;ppm$. $SC_{50}$ value of aronia extract against superoxide anion radical was $6.99{\pm}1.28\;ppm$. In addition, $IC\_{50}$ values of aronia extract against 5-LO, COX-1, and COX-2 were $42.07{\pm}0.15\;ppm$, $24{\pm}4.29\;ppm$, and $24.3{\pm}3.5\;ppm$, respectively. These results suggest that aronia extract may be useful for the prevention or treatment of allergic disease.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.804-809
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• 2005

The EtOAc-soluble fraction from a methanolic extract of Hovenia dulcis Thunb. exhibited neuroprotective activity against glutamate-induced neurotoxicity in mouse hippocampal HT22 cells. The neuroprotective activity-guided isolation resulted in 8 phenolic compounds (1-8), such as vanillic acid (1), ferulic acid (2), 3,5-dihydroxystilbene (3), (+)-aromadendrin (4), methyl vanillate (5), (-)-catechin (6), 2,3,4-trihydrobenzoic acid (7), and (+)-afzelechin (8). Among these, compounds 6 and 8 had a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells. Furthermore, compound 6 had a DPPH free radical scavenging effect with an $IC_{50}$ value of $57.7{\mu}M$, and a superoxide anion radical scavenging effect with an $IC_{50}$ value of $8.0{\mu}M$. Both compounds 6 and 8 had ABTS cation radical scavenging effects with $IC_{50}$ values of $7.8{\mu}M\;and\;23.7${\mu}M$, respectively. These results suggest that compounds 6 and 8 could be neuroprotectants owing to their free radical scavenging activities.

• The Journal of Korean Medicine
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• v.30 no.2
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• pp.88-103
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• 2009

Objectives: There is currently increased interest in the identification of natural antioxidant compounds derived from various plants. Peony Root (PR) is used worldwide for the treatment of many types of cardiovascular disease including atherosclerosis and hypertension. It has been used in Korean traditional medicine for the treatment of glycosuria, hypertension and cancer. However, to date, no studies concerning the antioxidant properties of PR have been conducted. Therefore, this study was conducted to evaluate the in vitro scavenging activity, inhibitory effect of LDL oxidation of pro-oxidant reactive species and anti-thrombosis effect in response to treatment with PR using various screening methods including biological and non-biological oxidants. Methods: In this study, the antioxidant activity of extract from PR was studied with in vitro methods by measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) [superoxide anion, hydroxyl radical] and on reactive nitrogen species (RNS) [nitric oxide and peroxynitrite] as well as measuring the inhibitory effect on $Cu^{2+}$-induced human LDL oxidation and the inhibitory effect on collagen-induced platelet aggregation. Results: The PR extracts were found to have a potent scavenging activity of oxidative stress [DPPH, superoxide anion, hydroxyl radical, nitric oxide and peroxynitrite, etc.] as well as an inhibitory effect on LDL oxidation and on platelet aggregation. Conclusions: The PR extracts have anti-oxidative and anti-atherosclerotic effects in vitro system, which can be used for developing pharmaceutical drugs against oxidative stress and atherosclerosis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.500-505
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• 2017

The nucleotides and their related compounds, including ATP (adenosine triphosphate), ADP (adenosine diphosphate), AMP (adenosine monophosphate), IMP (inosine monophosphate), HxR (inosine) and Hx (hypoxanthine), were nearly identical in oysters Crassostrea gigas from the two culture methods. The K-value was lower than the threshold value such as 11.2-12.1. Although oysters have low amount of IMP, it was detected in this experiment. DPPH radical scavenging activity did not vary significantly with sample amounts (100, 300, and $500{\mu}g/mL$). DPPH (1,1-diphenyl-2-picryl-hydrazyl) radical scavenging activity was 76.0-80.7% compare with the ascorbic acid standard. Superoxide anion scavenging activity reached 49.3% in the rack-and-bag culture sample at $500{\mu}g/mL$. However, the reducing power and $Fe^{2+}$ chelating activity were very low compared with their respective standard. The oyster culture methods did not affect oyster quality in terms of antioxidant activities.