• Biomedical Science Letters
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• v.15 no.4
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• pp.355-362
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• 2009

I evaluated the protective effect of N-methyl-D-aspartate (NMDA)/glycine receptor antagonist, 7-chlorokinurenic acid (CKA) on cultured mouse astrocytes damaged by ischemia-like condition (ILC). The protective effect of CKA was assessed by cell viability, lactate dehydrogenase (LDH) activity, superoxide dismutase (SOD)-like activity and lipid peroxidation. To examine the effect of CKA on the cell apoptosis, the expression and the activity of caspase 3 were assessed by Western blotting. CKA increased the cell viability decreased by ILC. CKA also decreased the LDH activity and antioxidative effects such as SOD-like activity and inhibitory activity of lipid peroxidation. In addition, CKA suppressed the expression of caspase 3 associated with apoptosis, and increased the cell viability by the decrease of caspase 3 activity as like the caspase 3 inhibitor, Av-DVED-MED. From these results, these results suggest that ILS induces cell cytotoxicity in cultured astrocytes and CKA, NMDA/glycine receptor antagonist, is effective on the prevention of the cytotoxicity due to ILS by the antioxidative effect and the inhibition of apoptosis.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1386-1391
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• 2009

Crude polysaccharides from rapeseed meal (PRM) were extracted with 0.3% NaOH aqueous solution, followed by further purifications and 2 fractions, namely PRM1 and PRM2, were separated with a DEAE-cellulose DE-52 column. Their primary compositions were analysed and antioxidant activity was determined, including scavenging activity toward superoxide anion radicals, hydroxyl radicals, and nitric oxide radicals, reducing power, and inhibitory effects against the microsomal lipid peroxidation, compared to that of L-ascorbic acid. The results indicated that PRM1 and PRM2 exhibited not only good reducing power and inhibitory effects on the microsomal lipid peroxidation, but also strong scavenging activity toward superoxide anion radicals, nitric oxide radicals, and hydroxyl radicals. In addition, positive correlations were also observed between the superoxide anion radical scavenging activity and the protein contents of the polysaccharides, and the reducing power and the sulfate contents. These findings thus clearly suggest the polysaccharides possess direct and potent antioxidant activity.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.600-608
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• 2019

The aim was to determine the physiological activity and antioxidant activity by lipid peroxidation inhibitory action of turmeric (Curcuma longa L.). Bioactive compound of total carotenoid $1.581{\pm}0.005mg$ ${\beta}$-carotene equivalents (BCE)/g dry weight. Total phenol content was the highest in the ethyl acetate (EA) extract, followed by chloroform:methanol (CM, 2:1, v/v) and 70% methanol extracts. Antioxidant effects (nitrogen oxide radical scavenging activity, nitrite scavenging activity, ${\beta}$-carotene bleaching assay, and lipid peroxidation inhibition action) of 70% methanol, CM, and EA extract of turmeric. Turmeric extracts yield were 70% methanol 16.54%, CM 5.64%, and EA 4.14%, respectively. Antioxidant activity of the samples exhibited a dose-dependent increase. However, in the current study, none of the samples evaluated showed activity as strong as the BHA (butylated hydroxyanisole) and trolox. Further, nitrite scavenging activity was the highest for the EA extract. As a result of this experiment, indicating their commercial value and potential applications in food and nutraceuticals.

• Preventive Nutrition and Food Science
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• v.15 no.1
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• pp.30-35
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• 2010

The potential biological activities of methanol extract and 5 fractions (hexane, $CH_2Cl_2$, EtOAc, BuOH and water) from roots of Astragalus membranaceus were examined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, hydroxyl radical (${\cdot}OH$) scavenging activity, reducing power assays, lipid peroxidation inhibitory activity, $\alpha$-amylase and $\alpha$-glucosidase inhibition assays. The EtOAc fraction showed high DPPH free radical scavenging activity ($EC_{50}=170.34\;{\mu}g/mL$), hydroxyl radical scavenging activity ($EC_{50}=32.14\;{\mu}g/mL$), lipid peroxidation inhibitory activity ($EC_{50}=52.46\;{\mu}g/mL$) and a concentration dependence, with OD value ranging from 0.234 to 0.345 (0.1 to 0.5 mg/mL), for reducing power. The EtOAc fraction has the highest total phenolic content ($142.13\;Gal\;{\mu}g/mg$) and the $CH_2Cl_2$ fraction has the highest flavonoid content ($71.63\;Que\;{\mu}g/mg$). Meanwhile, hexane and EtOAc showed certain $\alpha$-amylase and $\alpha$-glucosidase inhibition activities. These results suggest that the methanol extract and fractions from Astragalus membranaceus root have significant antioxidant and anti-diabetes activities, which could be used as a potential source of pharmaceutical materials.

• Korean Journal of Plant Resources
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• v.10 no.3
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• pp.227-230
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• 1997

The authors isolated four olefinic catechols, commonly referred to as urushiol, from the sap of Korean lacquer tree(Rhus vernicifera STOKES) with stronger antioxidative activities than $\alpha-tocopherol$. The hexane extract with a free radical scavenging activity was purified by silica and ODS gel column chromatography. The active compounds were identified by MS and $^1H-NMR$ as 3-[8'(Z),11'(Z),14'-pentadecatrienyl]catechol, 3-[8'(Z),11'(Z)-pentadecadienyl]catechol, 3-[8'(Z)-pentadecenyl] catechol, and 3-pentadecylcatechol. All of these compounds showed strong free radical scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, in which 3-pentadecylacatechol exhibited the highest activity ($IC_{50}$: $1.2{\mu}g/ml$). They also showed a significant inhibitory activity on lipid peroxidation ($IC_{50}$: 2.1 - 3.5 ${\mu}g/ml$). The antioxidative activity of 3-pentadecylcatechol on DPPH radical and lipid peroxidation is approximately two times greater than that of $\alpha$-tocopherol. The results suggest that the urushiol derivatices may contribute to the preservative characteristics effective against oxidative stress and could be a good source for industrial applications including a coating material.

• International Journal of Oral Biology
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• v.30 no.3
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• pp.77-84
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• 2005

EGCG[(-)-epigallocatechin gallate], is a major component of green tea has been considered as a major antioxidant constituent. It has been considered as potential chemopreventive and chemotherapeutic agents. However, very little is known about the cellular actions by which EGCG mediates its therapeutic effects. Various aspects of antioxidant activity of EGCG were evaluated in this study. EGCG itself did not show significant cytotoxicity. Significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was observed in all ranges of concentration ($0.8-100{\mu}g/ml$) used in this study. Protective effect of EGCG against hydrogen peroxide induced cell death was observed. Relatively high lipid peroxidation inhibitory activity were detected ($IC_{50}$ was about $20{\mu}g/ml$). EGCG also dose-dependently enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in V79-4 cells. In concentrations of $100{\mu}g/ml$ of EGCG, activities of SOD, CAT and GPX were measured as 36.9 U/mg of protein, 22.9 U/mg of protein and 17.8 U/mg of protein, respectively. When these values were compared with those of the control groups (24.9 U/mg of protein, 14.9 U/mg of protein and 11.7 U/mg of protein), the relative increases were calculated as 48, 54 and 52%, respectively. Taken together, our findings suggest that EGCG can act as an antioxidant by scavenging radicals and enhancing antioxidant enzyme activities.

• 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.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.377.2-377.2
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• 2002

The MeOH extract of the twig of Marus alba L. (Moraceae) inhibited strong lipid peroxidation activity. Five antioxidative compounds were isolated through activity-guided fractionation. and identified as 6-geranylapigenin (1). 6-geranylnorartocarpetin(2). resveratrol (3). oxyresveratrol (4). quercetin (5) by physicochemical and spectrometric methods. In order to evaluate the antioxidant effect of these compounds. the lipid peroxidation inhibitory activity test were performed. Compounds 1-5 showed greater activity than tocopherol. (omitted)

• Korean Journal of Acupuncture
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• v.25 no.4
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• pp.89-104
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• 2008

Objectives : This study was undertaken to determine the in vitro antioxidant activity of the extract of Chilgitang herb-acupuncture solution (CHAS). Methods : The radical scavenging capacity was tested by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), hypoxanthine-xanthine oxidase system, DCFH-DA assay, nitric oxide and peroxynitrite generating system. In addition, antioxidant activity on copper and AAPH mediated human low-density lipoprotein (LDL) oxidation was measured by using TBARS assay and relative electrophoretic mobility assay. The amount of total phenolic compounds was assayed by the Folin-Ciocalteu method. Results : CHAS revealed a potent scavenging activity on DPPH radical(82%), superoxide anions(73%), hydroxyl radical(63%), nitric oxide (99%) and peroxynitrite (99%). Moreover, CHAS showed a strong inhibitory effect (59%) on $FeCl_2$-ascorbic acid induced lipid peroxidation of rat liver homogenate. CHAS also markedly inhibited copper(81%) and AAPH(56%)-mediated LDL oxidation, and effectively suppressed the electrophoretic mobility during exposure of human LDL to copper ions. CHAS (82 mg/g) contained higher concentration of total phenolic compounds than that of water extract (45 mg/g) obtained from Chilgitang. Conclusions : These results indicate that CHAS may protect against ROS- or RNS involved diseases, including cardiovascular diseases.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.137-141
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• 2008

The present study reports the protective properties of a total methanol extract of B. platyphylla var. japonica against ultraviolet (UV)-C irradiation. Pretreatment of Chinese hamster fibroblast (V79-4) cells with a total methanol extract significantly increased cell survival following $300\;J/m^2$ of UV-C irradiation. The total methanol extract was further fractionated into 5 fractions: n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these fractions, B. platyphylla var. japonica ethylacetate, butanol and water fractions showed significant protective effects against the cellular damage induced by UV-C irradiation. In order to elucidate the mechanism underlying this protective effect, DPPH (Editor note: abbreviations should be spelled out at first use.) radical scavenging and lipid peroxidation inhibitory activity were measured. Significant radical scavenging and lipid peroxidation inhibitory activities were observed for the ethylacetate fraction. In summary, the present data demonstrate that an extract of B. platyphylla var. japonica has a significant protective effect against UV-C irradiation. The underlying mechanism of this protective effect may involve radical scavenging and inhibition of lipid peroxidation by the B. platyphylla var. japonica extract.