• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.150-157
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• 2007

Hamcho(Salicorinia herbacea, glasswort), a halophyte, is an annual succulent shrub that grows on coastal wetlands and has been regarded as a functional food for good health. Natural dried red and green Hamcho were extracted with 25% ethanol and water at 70$^{\circ}C$. The antioxidant activities of these four extracts were examined by six different assays, including the measurement of total phenolics, radical scavenging effects on 1,1-diphenyl-2-picrylhydrazyl(DPPH), nitric oxide(NO) and nitrite(NO$_2$) scavenging effects, reducing power, and the inhibitory effect on tyrosinase activity. The total phenolic contents of the four extracts were high at 237 ${\sim}$ 255 mg of gallic acid equivalents per 1 g of dried sample tested. The green Hamcho extracts contained more phenolic compounds than the red Hamcho extracts. When they were compared to tocopherols, the antioxidant activities of the green and red Hamcho powders were significantly higher at the same concentration levels(5 mg and 3 mg, respectively) in a POV test. The inhibition effects of the four extracts at a level of 75 ${\mu}l$ were higher than 98% in the POV test. The red Hamcho 25% ethanol extract showed a high significant effect on DPPH radical scavenging(SC$_{50}$, 90.1 ${\mu}l$). The green Hamcho 25% ethanol extract, however, showed a high significant effect on NO radical scavenging(SC$_{50}$, 6.1 ${\mu}l$). The NO$_2$ radical scavenging effect was assayed at pH 1.2, 4.2 and 6.0, and all the Hamcho extracts scavenged the NO$_2$ radical much more effectively at pH 1.2. The NO$_2$ scavenging effect of the red Hamcho 25% ethanol extract(64%) was as high as that of 5 mM vitamin C at pH 1.2(p<0.05). In the reducing power test, the red Hamcho 25% ethanol extract revealed the highest ferric ion reducing activity among the Hamcho extracts, and its activity was as high as that of 0.33 mg/ml of vitamin C. The four Hamcho extracts showed high tyrosinase inhibition effects of more than 80%, and their activities were higher than 50${\mu}$g of kojic acid. The green and red Hamcho 25% ethanol extracts totally inhibited tyrosinase activity(100%). Therefore, the results suggest that red Hamcho extracts may serve as useful natural antioxidants along with green Hamcho extracts.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.

• Biomedical Science Letters
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• v.14 no.3
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• pp.193-198
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• 2008

In order to evaluate on the effect of kaempferol on the cytotoxicity of oxygen tree radicals, XTT assay was performed to determine the cell viability after skin fibroblasts derived from human (Detroit 51) that were treated with various concentrations of hydrogen peroxide $(H_2O_2)$. And also, the effect of kaempferol on the cytotoxicity induced by H202 that was examined by cell viability, lactate dehydrogenase (LDH) activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in these cultures. $H_2O_2$ decreased cell viability in dose-dependent manner in these cultures and the $XTT_{90}\;and\;XTT_{50}$ values were determined at concentration of $35{\mu}M\;and\;90{\mu}M$ of $H_2O_2$ after skin fibroblasts derived from human were treated with $15{\sim}90{\mu}M$ of $H_2O_2$ for 6 hours, respectively. $H_2O_2$ was highly toxic on cultured skin fibroblasts derived from human by toxic criteria of Brenfreund and Puerner (1984). In the protective effect of kaempferol on $H_2O_2$-induced cytotoxicity, kaempferol increased DPPH radical scavenging activity and significantly decreased LDH activity. From these results, it is suggested that oxygen tree radical, $H_2O_2$, was highly toxic on cultured skin fibroblasts derived from human, and also kaempferol of flavonoid showed the protection on $H_2O_2$-induced cytotoxicity.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.775-783
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• 2005

The ethanol extract of the peony root (Paeonia Lactiflora Pall, Paeoniaceae) as well as its major active components including gallic acid and methyl gallate were evaluated for their protective effects against free radical generation and lipid peroxidation. In addition, the protective effects against hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line were examined. The ethanol extracts of the peony root (PREs) and its active constituents, gallic acid and methyl gallate, exhibited a significant free radical scavenging effect against 1,1-diphenyl-2-picryl hydrazine (DPPH) radical generation and had an inhibitory effect on lipid peroxidation, as measured by the level of malondialdehyde (MDA) formation. The PREs did not have any pro-oxidant effect. They strongly inhibited the hydrogen peroxide-induced DNA damage from NIH/3T3 fibroblasts, as assessed by single cell gel electrophoresis. Furthermore, the oral administration of 50% PRE (50% ethanol extract of peony root), gallic acid and methyl gallate potently inhibited the formation of micronucleated reticulocytes (MNRET) in the mouse peripheral blood induced by a $KBrO_3$ treatment in vivo. Therefore, PREs containing gallic acid and methyl gallate may be a useful antigenotoxic antioxidant by scavenging free radicals, inhibiting lipid peroxidation and protecting against oxidative DNA damage without exhibiting any pro-oxidant effect.

• Preventive Nutrition and Food Science
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• v.15 no.1
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• pp.44-50
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• 2010

Hawthorn fruit is a conventional medicine used in treating cardiovascular diseases. Its therapeutic effects may relate to its antioxidant compounds. In this study, we evaluated the antioxidant activity of $CH_2Cl_2$, EtOAc, n-butanol and water fractions from 70% methanolic hawthorn fruit extract by total phenolic and flavonoid contents, total antioxidant activity, DPPH free radical scavenging activity, superoxide radical scavenging activity, reducing power assay, lipid peroxidation inhibitory activity and protective effect against hydroxyl-radical-induced DNA damage. Results showed that the EtOAc fraction contained significantly greater antioxidant activities than other fractions, which suggests that the potent EtOAc fraction should be used for further studies to identify the antioxidant compounds.

• The Korea Journal of Herbology
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• v.27 no.3
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• pp.23-29
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• 2012

Objective : Sanguisorbae Radix(SO). that belong to Rosaceae is widely distributed in Asia including Korea, Japan and China. It has been used as traditional medicine from old times as a treatment for anti-inflammatory drugs. This study was designed to investigate the effects of n-BuOH fractions of SO on anti-oxidant effect and anti-microbial effect on $Streptococcus$ $mutans$ ($S.$ $mutans$). Methods : The anti-microbial effect of $n$-BuOH fractions of SO. was assessed by the paper disk diffusion method and anti-oxidant effect was assessed by the DPPH radical scavenging effect, Superoxide anion radical scavenging effect and SOD like ability. Results : DPPH radical scavenging of the $n$-BuOH fraction from SO in 50 ug/mL was shown to be Fr-2 (89.9%), Fr-3 (88.7%), Fr-4 (76.3%), Fr-1 (59.4%), Fr-5 (56.2%). Superoxside anion radical scavenging activity of the n-BuOH fraction from SO. in 50 ug/mL for Fr-3 was shown to be 78%. SOD-like activity of n-BuOH fraction from the SO in 1000 ug/mL for Fr-3 were shown to be 76.1% respectively. The $n$-BuOH fraction from the SO had high anti-microbial effect on $S.$ $mutans$. Conclusion : As a result, the $n$-BuOH fraction from SO. has good anti-microbial and anti-oxidant effects in a concentration-dependent manner.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.548-556
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• 2013

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of cucumber grown greenhouse. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging, nitrite scavenging ability activity and ABTS radical scavenging ability. The DPPH free radical scavenging activity of Jangjukcheongjang was the highest in most of the growth stage. The Nitrite scavenging ability at pH 1.2 was more than 40% in all cultivars and growth stages. The ABTS radical scavenging ability of Jangjukcheongjang and Nulpureuncheongjang showed relatively little higher than Janghyeongnakhap and Sinjoeunbaekdadagi. The SOD activity showed higher activity than 95% in all cultivars and growth stages. The activity of CAT was highest in the Nulpureuncheongjang of 2 (12~16cm) growth stage, and the APX activity of Nulpureuncheongjang and Janghyeongnakhap showed a relatively high activity. The POX activity showed distinctly different trends depending on the growth stage, and that is, the activity at harvest stage was significantly reduced. These results suggest that the cucumber had the potent biological activities, and that in the future, the availability of cucumber will be increase in the field of high-value cosmetic and food products.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.713-719
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• 2011

The antioxidant activities of the ethanol extract of Arctium lappa were assessed by measuring the 1,1-diphenyl-2-picrylhydrazyl( DPPH) radical scavenging effect, inhibition of $Fe^{2+}$-induced lipid peroxidation, inhibition of malondialdehyde(MDA)-bovine serum albumin(BSA) conjugation reaction and antimutagenic capacities using the Ames test. The DPPH radical scavenging activity and inhibition of $Fe^{2+}$-induced lipid peroxidation of the $Arctium$ $lappa$ ethanol extract significantly increased in a dose-dependent manner. In the radical scavenging assay using DPPH, the $IC_{50}$ of the Arctium lappa extract was 296 ${\mu}g$/assay(1.29 mg of dry sample). In addition, the $IC_{50}$ in the inhibition of $Fe^{2+}$-induced lipid peroxidation was 1,759 ${\mu}g$/assay(7.65 mg of dry sample). This extract also significantly inhibited the MDA-BSA conjugation reaction with an $IC_{50}$ of 57.58 mg/assay(250 mg of dry sample). However, no inhibitory effects against the direct and indirect mutagenicities in $Salmonella$ Typhimurium TA98 and TA100 were observed. Based on these results, the ethanol extract of $Arctium$ $lappa$ was shown to display considerable antioxidative activities.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.614-620
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• 2005

The antioxidative effect of Ecklonia cava, a brown marine alga, was investigated on radical scavenging, including 1,1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl and alkyl radicals, using an electron spin resonance (ESR) technique, and on the inhibition of $H_2O_2$-induced DNA damage using comet assay. E. cava was enzymatically hydrolyzed with five food industrial proteases (Alcalase, Flavourzyme, Kojizyme, Neutrase and Protamex) to prepare water-soluble extracts. All the proteolytic hydrolysates exhibited strong dose-dependent radical scavenging activities (above 80%) at a concentration of $2.5\;{\mu}g/mL$. Kojizyme extract (obtained by proteolytic hydrolysation of E. cava with Kojizyme) showed the highest hydroxyl radical scavenging activity of around 98%. In addition, the $H_2O_2$-induced DNA damage was determined using a comet assay, which was quantified by measuring the tail length. Reduction of DNA damage increased with increasing concentrations of Kojizyme extract from E. cava. These results indicated that E. cava has a potential as a valuable natural antioxidative source.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.401-404
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• 2008

Seolitae Chungkukjang added with different ratios of green tea was prepared to increase the antioxidative activity of Chungkukjang. The physicochemical properties and the radical scavenging effect under in vitro were evaluated. The addition of green tea to Seolitae Chungkukjang (SC) revealed lower pH, green color and decrease in levels of NH3-N. Among the Chungkukjang group with Seolitae or green tea, SC with green tea 5.0% (SCG 5.0) showed the strongest scavenging activity against 1,1-diphenyl-2-picrylhydrazyl with $IC_{50}$ value of $82.1{\mu}g$/mL. In addition, SCG 5.0 exerted the most effective ${\cdot}OH$ scavenging activity. Moreover, SCG 5.0 showed the similar sensory preference to control soybean Chungkukjang. The present study suggests that SC exerts radical scavenging effect, and that the addition of green tea to SC leads to the increase in the antioxidative effect of Chunkukjang.