• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.78-83
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• 2005

Recently, much attention has been focused on plant antioxidants, because they are expected to protect against oxidative damage, possibly preserving biological functions of cells. Antioxidant compounds were isolated from Angelica keiskei through extraction with 80% EtOH, and fractionations were carried out sequentially with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Two active compounds were isolated from ethyl acetate fraction by silica gel column chromatography, and were identified as isoquercitrin ($quercetin-3-O-{\beta}-D-glucose$) and hyperoside ($quercetin-3-O-{\beta}-D-glucose$). Isoquercitrin and hyperoside showed strong antioxidative potency, as revealed by evaluation of their ABTS, DPPH, OH, and $H_{2}O_{2}$ radical-scavenging activities, and ex vivo DNA damage-protecting effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.695-701
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• 2015

This study was conducted to evaluate the effects of drying and extraction methods on antioxidant activity and total phenol content of Gnaphalium affine D. DON (GA). Hot-air, shade-drying, and freeze-drying were used for drying, after which magnetic stirring and ultrasonification were applied. Extracting solvents were water, 80% ethanol, and 80% methanol. Total phenol content was highest in 80% ethanol extract of freeze-dried and stirred GA. Total flavonoid content was highest in 80% methanol extract of freeze-dried and stirred GA. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was higher in 80% methanol and 80% ethanol extracts than in water extract. 2,2-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was highest in 80% ethanol extract of shade-dried and ultrasonicated GA. Reducing power was generally higher in 80% methanol extract than in 80% ethanol and water extracts of GA. Total phenol and total flavonoid contents were highly correlated with DPPH radical scavenging activity and reducing power, respectively. This result implies that the antioxidant activity of GA can be attributed to phenol compounds such as flavonoids. Conclusively, phenol compounds such as flavonoids are responsible for the antioxidant activity of GA, and there was no significant effect of drying and stirring conditions on antioxidant activity of 80% ethanol. Meanwhile, DPPH radical scavenging activity of water extract and reducing power of 80% methanol extract were higher in hot-air and shade-dried GAs than in freeze-dried GA.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.539-546
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• 2016

The aim of this study was to analyze antioxidant activity, total phenolics, and vitamin C content in unripe and ripe jujube cultivar and to investigate correlation between antioxidant and chemical constituents including total phenolics and vitamin C. The antioxidant activity was measured by the DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power. Although, the weight, diameter and soluble solids of Zyziphus jujuba fruit were increased with the progress of ripening, antioxidant activity and total phenolics were decrease during ripening. The highest free-radical scavenging activity (at 2.5 ㎎/㎖) and reducing power (at 1 ㎎/㎖) in fruit were 81.75% (Bokjo, unripe) and 0.80 (Mudeung, unripe), respectively. The highest total phenolic content in unripe fruit of Mudeung was 62.50 ㎍/g. A linear correlation (r=0.911) was shown between DPPH radical scavenging activity and total phenolic content.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.510-515
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• 2018

In the present study, we investigated the anti-oxidant activities of selenium-treated Spinacia oleracea L. by utilizing experiments in vitro assays. The selenium content of non-treated spinach in this study was noted at $61.19{\mu}g/kg$, whereby the selenium-treated spinach which was treated by a 2000 mg/kg selenium was 1000-fold diluted, and was reported to be about 4 times higher than that of non-treated spinach. In this case, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in the concentration of selenium-treated spinach, 0.1~1.0 mg/mL was measured as stronger than that of the identified non-treated spinach. By the same token, the DPPH radical activity of non-treated spinach and selenium-treated spinach was recorded as 46.05~52.75% and 49.52~59.09% respectively. It is emphasized that the 2,2'-azino-di-2-ethyl-benzthiazoline-sulphonate (ABTS) radical scavenging activity as revealed in the concentration of selenium-treated spinach, 0.1~1.0 mg/mL was noted as being stronger than that of non-treated spinach. The ABTS radical activity of non-treated spinach and selenium-treated spinach was 11.85~52.01% and 27.14~53.59% respectively. In this respect, the nitric oxide (NO) radical scavenging activity and reducing power activity in the concentration of selenium-treated spinach, 0.1~1.0 mg/mL was identified and noted as stronger than that of non-treated spinach. These results suggest that selenium-treated spinach could possibly be more useful as a potential antioxidant to improve human health outcomes, than the non-treated spinach.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.286-290
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• 2003

Effects of Ramaria botrytis methanol extract on hepatotoxicity in $benzo({\alpha})pyrene(B({\alpha})P)-treated$ mice were investigated. R. botrytis methanol extract was intraperitioneally injected once a day for successive 5 days, followed by treatment with $B({\alpha})P$ on the fifth day. Antioxidant activities of R. botrytis methanol extract were examined by measuring the free radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. In DPPH method, R. botrytis methanol extract showed strong antioxidative activies. The increased activities of superoxide dismutase, catalase, and glutathione peroxidase after $B({\alpha})P-treatment$ were decreased by treatment of R. botrytis methanol extract. Glutathione content and glutathione S-transferase activity depleted by $B({\alpha})P$ were significantly increased, but elevation of lipid peroxide content induced by $B({\alpha})P$ was decreased by R. botrytis methanol extract. These results suggest that R. botrytis methanol extract is believe to be a possible protective effect against $B(\alpha)P-induced$ hepatotoxicity in mice.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1320-1326
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• 2018

This study investigated the antioxidant and neuronal cell protective effects of activity of water and 70% ethanol extracts from Stachys sieboldii Miq. according to different drying method(hot air drying and freeze-drying). The total flavonoid and total polyphenol content in water extracts was significantly higher after freeze-drying compared to hot air drying(p<0.05). DPPH and ABTS radical scavenging were increased in a dose-dependent manner. The DPPH and ABTS radical scavenging activity of water extract were significantly higher after free-drying compared to hot air drying(p<0.05). In a cell viability using MTT, the water extract according to hot air drying and freeze-drying of Stachys sieboldii Miq. showed protective effect against H2O2-induced nurotoxicity. The results suggest that the water extracts of Stachys sieboldii Miq. after freeze-drying has antioxidant activities and may be useful for neurodegenerative disorders.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.566-570
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• 2013

Vaccinium oldhamii Miq. is a Korean native tree, which is deciduous and shrub tree with broad leaf. To develop superior cultivars for edible or medicinal purposes, we evaluated total phenolic content and antioxidant activity. Total phenolic content was measured by folin-denis method and antioxidant activity was measured by DPPH free radical scavenging activity (DPPH method) and reducing power (potassium ferricyanide method). Total phenolic content, DPPH free radical scavenging activity (at 400 ppm) and reducing power (at 700 ppm) were 15.8~19.9 mg/g, 69.1~91.4% and 0.56~0.96, respectively. A linear correlation was shown between DPPH-radical scavenging activity and reducing power (r=0969).

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.719-730
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• 2014

The hot water extract from Artemisia capillaris fermented with Hericium erinaceum mycelium (AC-HE) were assessed for the protection against oxidative modification of biological macromolecules and cell death. Antioxidant activity of AC-HE evaluated using 2,2-diphenyl-1-picrylhydrazyl radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical and peroxyl radical scavenging assays. AC-HE showed 61.73% DPPH radical scavenging activity at $500{\mu}g/mL$, 97.39% ABTS radical scavenging activity at $250{\mu}g/mL$, and 44.18% peroxyl radical scavenging activity at $100{\mu}g/mL$. AC-HE were shown to significantly inhibited DNA strand breakage induced by peroxyl radical. AC-HE also prevented peroxyl radical-mediated human serum albumin modification. AC-HE effectively inhibited $H_2O_2$ induced cell death and significantly increased of the 11.47% cell survival at $100{\mu}g/mL$. AC-HE also decreased intracellular reactive oxygen species (ROS) levels in $H_2O_2$-treated cells. The results suggested that AC-HE can contribute to antioxidant and protected cells from oxidative stress-induced cell injury.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.295-301
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• 2015

Biological compounds such as crude saponin and total polyphenol were determined in Allium hookeri roots and leaves. In addition, activities of DPPH radical scavenging activity, hydroxyl radical scavenging activity, ${\alpha}$-amylase inhibition activity and nitrite scavenging were detected in concentrates of 70% ethanol extracts of Allium hookeri roots and leaves. The crude saponin content of the roots and leaves were 4.28 mg/g, and 4.17 mg/g, respectively. Total polyphenol and total flavonoid content was higher in leaves than roots. Furthermore the DPPH radical scavenging activity and hydroxyl radical scavenging activities of leaves was higher than roots. For ${\alpha}$-glucosidase inhibitory activity, 70% ethanol extracts of Allium hookeri roots and leaves showed 60% activity inhibition at a 10 mg/mL concentration. Nitrite scavenging abilities under acidic conditions were most effective for Allium hookeri leaves extracts. These results suggested that Allium hookeri leaves might be used as the components of health functional food.

• Food Science and Preservation
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• v.17 no.2
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• pp.267-274
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• 2010

To obtain basic information on the potential use of Camellia japonica leaf as a raw material in functional food, leaf antioxidant and anticancer activities were investigated. The radical-scavenging activity of various solvent fractions from the leaf, as shown by the DPPH radical test, increased in a dose-dependent manner, with the water fraction showing the highest activity. The reducing power of various solvent fractions from the leaf was also dose-dependent, and, again, the water fraction showed the highest reducing power. The water fraction showed strong antioxidant activity in the linoleic acid test and was also capable of scavenging nitrite in a dose-dependent manner. Proportions of 92.15% and 95.61% of available nitrite were scavenged by the water and butanol fractions, respectively, at levels of $1,000{\mu}g/mL$. Both butanol and water fractions exhibited strong inhibitory effects on the growth of human lung and colon cancer cells. The total phenolic contents of the butanol and water fractions were 216.26 mg/g and 220.68 mg/g, respectively. High-performance liquid chromatography (HPLC) showed that quercetin and epicatechin were the predominant phenolic compounds in the water fraction. The activities of this fraction are attributable to the presence of these phenolic compounds, particularly quercetin and epicatechin.