• Korean Journal of Pharmacognosy
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• v.36 no.2 s.141
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• pp.81-87
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• 2005

The effects of the DWP-04 [DDB:selenium yeast:glutathione (31.1 : 6.8 : 62.1 (w/w%)] on acetaminophen detoxification enzyme system were studied in rats. Treatment with DWP-04 was prevented againt acetaminophen-induiced hepatotoxicity in rat as evidenced by the decreased formation of lipid peroxide. Effect of DWP-04 on the activities of free radical-generating enzymes, free radical scavenging enzymes and glutathione-related enzymes as well as detoxification mechanism of DWP-04 against acetaminophen-treated was investigated in rat. Activities of cytochrome p450, cytochrome b5, aminopyrine demethylase and aniline hydroxylase as free radical-generating enzymes activities were decreased by the treatment with DWP-04 against acetaminophen treated. Although acetaminophen-induced hepatotoxicity results in the significantly decrease in the level of hepatic glutathione and activities of glutathine S-transferase, quinone reductase, glutathione reductase and ${\gamma}-glutamyl-$cysteine synthetase, these decreasing effects were markedly lowered in the DWP-04-treated rat. Therefore, it was concluded that the mechanism for the observed preventive effect of DWP-04 against the acetaminophen-induced hepatotoxicity was associated with the decreased activities in the free radical-generating enzyme system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.937-941
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• 2003

Red mustard leaf (RML) kimchi was prepared with native Brassica juncea czerniak et coss as a major raw material and antioxidative characteristics of crude anthocyanin (CA)/refined anthocyanin (RA) isolated from RML kimchi were studied. Among crude pigment fractions, CA fraction showed a higher inhibition rate of peroxide formation in linoleic acid autoxidation system. These effects seemed to be increased with the increase of CA concentration. CA also was considered to have a role of electron donor by the experiments using DPPH ($\alpha$, $\alpha$＇-diphenyl-$\beta$-picrylhydrazyl) reaction. Furthermore, various RA fractions had a higher antioxidative activity and especially RA-fraction 3 demonstrated the highest score of the antioxidative characteristics in terms of the prevention of lipid peroxidation and scavenging of free radicals.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.2 s.33
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• pp.1-9
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• 2007

Objective : In this study, the ethanol extract from flowers of Lespedeza bicolor was investigated for their dermal bioactive properties related to cosmeceuticals such as depigmentation and radical scavenging effect. Results : The ethanol extract from flowers of Lespedeza bicolor showed considerable radical scavenging activity ($SC_{50}:\;10\;{\mu}g/ml$) and inhibited the production of nitric oxide (NO) in Raw 264.7 macrophages activated with the endotoxin lipopolysaccharide (LPS). Although the proliferation of B16/F10 cells was slightly decreased by the ethanol extract from flowers of Lespedeza bicolor at the concentration of $100\;{\mu}g/ml$, it did not appear necrosis. The ethanol extract from flowers of Lespedeza bicolor down-regulated melanin formation effectively. Methods : The free radical scavenging activity of Lespedeza bicolor was assayed in cell free systems using a stable free radical, 1,l-diphenyl-2-picrylhydrazyl (DPPH). Nitrite accumulated in culture medium was measured as an indicator of NO production using a Griess reaction. Cell viability was measured by MTT assay and melanin content was assessed using the method of Hosei with some modifications. Conclusions : These results suggest that the ethanol extract from flowers of Lespedeza bicolor is a potent depigmetation agent and it may be a candidate for antioxidant and anti-inflammatory agent.

• The Korea Journal of Herbology
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• v.23 no.4
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• pp.121-134
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• 2008

Objectives: Melia toosendan(MT) has been used as a traditional Korean herbal medicine, and today it is used as a medication for colic, side aches, heartache and other disorders of liver. The aim of this study was to determine whether fractionated extracts of MT inhibit free radical generation such as DPPH radical, superoxide radical and nitric oxide, production of nitrite, an index of NO, PGE2, iNOS, COX-2 and proinflammatory cytokines in lipopolysaccharide(LPS)-treated RAW 264.7 macrophages. Methods: MT extract prepared with methanol, and then fractionated with hexane, dichloromethane, ethylacetate, n-butanol and water. Inhibitory effect of MT onto free radical generation was determined by measuring DPPH, superoxide anions and nitric oxide scavenging activities in vitro. Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt(MTS) assay. Intracelluar oxidation was analysed by DCF-DA assay. The nitric oxide(NO) production was measured by Griess reagent system. The levels of iNOS and COX-2 expression were confirmed by western blot. And pro inflammatory cytokines were measured by ELISA kit. Results: Our results indicated that fractionated extracts, especially dichloromethane and ethyl acetate extracts, significantly inhibited free radical generation, the LPS-induced $H_2O_2$, NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-1${\beta}$ and IL-6 formation in macrophages. Conclusions: These results indicate that dichloromethane and ethyl acetate extracts of MT have potential as an agent of chronic inflammatory diseases.

• Biomolecules & Therapeutics
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• v.11 no.3
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• pp.196-199
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• 2003

The methanol extracts from 60 plant extracts were prepared and evaluated for their antioxidative activity. Arctium lappa, Diospyros kaki, Eugenia caryophyllata, Melia azedarach and Forsythia suspensa showed the inhibitory activity against lipid peroxidation. Caesalpinia sappan, Crataegus pinnatifida, Eugenia caryophyllata, Gleditsia japonica, Osmunda japonica, Rhus javanica and Sanguisorba officinalis showed the highest inhibitory activity against DPPH radical formation. In particular, Eugenia caryophyllata demonstrated strong inhibitory activity on the lipid peroxidation and free radicals. The results suggested that selected plant extracts have a potential as natural antioxidant.

• Molecules and Cells
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• v.22 no.2
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• pp.220-227
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• 2006

Oxidative alteration of mitochondrial cytochrome c has been linked to disease and is one of the causes of proapoptotic events. We have investigated the modification of cytochrome c by $H_2O_2$. When cytochrome c was incubated with $H_2O_2$, oligomerization of the protein increased and the formation of carbonyl derivatives and dityrosine was stimulated. Radical scavengers prevented these effects suggesting that free radicals are implicated in the $H_2O_2$-mediated oligomerization. Oligomerization was significantly inhibited by the iron chelator, deferoxamine. During incubation of deoxyribose with cytochrome c and $H_2O_2$, damage to the deoxyribose occurred in parallel with the release of iron from cytochrome c. When cytochrome c that had been exposed to $H_2O_2$ was analyzed by amino acid analysis, the tyrosine, histidine and methionine residues proved to be particularly sensitive. These results suggest that $H_2O_2$-mediated cytochrome c oligomerization is due to oxidative damage resulting from free radicals generated by a combination of the peroxidase activity of cytochrome c and the Fenton reaction of free iron released from the oxidatively-damaged protein.

• Toxicological Research
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• v.21 no.2
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• pp.115-119
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• 2005

In the present study, we evaluated the free radical scavenging and xanthine oxidase inhibitory activities exhibited by extracts obtained from the dried stems (and leaves) of Lespedeza bicolor We also assessed its potential irritation activities with regard to cosmetic use. When the DPPH radical scavenging activities of L. bicolor were assessed at six different concentrations (0, 50, 100, 250, 500 and 1000 ${\mu}g/ml$), the concentration of L. bicolor required to inhibit DPPH radical formation by $50\%$ was found to be $164.90{\mu}g/ml$. The effects of L. bicolor on the inhibition of xanthine oxidase were determined at seven different concentrations. The $50\%$ effective concentration was found to be $282.75{\mu}g/ml$. In the skin irritation test, all animals survived for the duration of the study, and all exhibited normal gains in body weight. The control sites exhibited no response to the control procedures. No edema, erythema, or eschar formation was observed in any of the tested rabbits. In the ocular irritation study, all of the rabbit eyes remained normal. In summary, L. bicolor extracts were considered to be non-irritating to the skin and eye.

• Animal cells and systems
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• v.9 no.2
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• pp.79-85
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• 2005

Oxidized abasic residues arise as a major class of DNA damage by a variety of agents involving free radical attack and oxidation of deoxyribose sugar components. 2-deoxyribonolactone (dL) is a C1'-oxidized abasic lesion implicated in DNA strand scission, mutagenesis, and covalent DNA-protein cross-link (DPC). We show here that mammalian cell-free extract give rise to stable DPC formation that is specifically mediated by dL residue. When a duplex DNA containing dL at the site-specific position was incubated with cell-free extracts of Po ${\beta}-proficient$ and -deficient mouse embryonic fibroblast cells, the formation of major dL-mediated DPC was dependent on the presence of DNA polymerase (Pol) ${\beta}$. Formation of dL-specific DPC was also observed with histones and FEN1 nuclease, although the reactivity in forming dL-mediated DPC was significantly higher with Pol ${\beta}$ than with histones or FEN1. DNA repair assay with a defined DPC revealed that the dL lesion once cross-linked with Pol ${\beta}$ was resistant to nucleotide excision repair activity of cell-free extract. Analysis of nucleotide excision repair utilizing a model DNA substrate containing a (6-4) photoproduct suggested that excision process for DPC was inhibited because of DNA single-strand incision at 5' of the lesion. Consequently DPC mediated by dL lesion may not be readily repaired by DNA excision repair pathway but instead function as unusual DNA damage causing a prolonged DNA strand break and trapping of the major base excision repair enzyme.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.327-334
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• 2020

Oxidative stress is common cause of neurodegenerative diseases. The purpose of this study is to investigate the in vitro free radical scavenging activity and protective effect of three Glycyrrhiza species including Glycyrrhiza uralensis, G. glabra, and a new variety of Glycyrrihza (Shinwongam, SW) against hydrogen peroxide-induced oxidative stress in C6 glial cells. In vitro assays, radical scavenging activities of G. uralensis, G. glabra, and SW against 2,2-diphenyl-1-picrylhydrazyl, ·OH, and O2- increased as concentration-dependent manner. In addition, the SW was found to contain the highest polyphenol and flavonoid contents. The treatment of H2O2 to C6 glial cell induced oxidative stress, whereas G. uralensis, G. glabra, and SW significantly increased the cell viability as dose-dependent manner. In particular, SW exerted stronger protective effect on H2O2-induced cytotoxicity, than G. uralensis and G. glabra. Furthermore, reactive oxygen species (ROS) formation was significantly elevated by H2O2 in C6 glial cells. However, treatments of G. uralensis, G. glabra, and SW decreased ROS formation. In addition, SW decreased pro-inflammatory related protein expression levels such as inducible nitric oxide synthase and cyclooxygenase-2, compared to H2O2-treated control group. These results indicated that G. uralensis and G. glavra, especially SW, may be useful for preventing from oxidative stress-induced neuronal damage by regulating inflammatory reaction.

• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.150-155
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• 2004

The free radical scavenging activities and the protective effects of Rhus javanica extracts against oxidative damage induced by reactive oxygen species (ROS) were investigated. n-Hexane, ethyl acetate and water fractions were prepared from a methanol extract. DPPH radical, superoxide anion and hydroxyl radical scavenging activities were estimated. Intracellular ROS formation was quantified using fluorescent probes, 2', 7'-dichlorofluorescin diacetate (DCFH-DA) for hydroxyl radical and dihydroethidium (DHE) for superoxide anion. The oxidative DNA damage was investigated by the comet assay in HepG$_2$ cells exposed either to $H_2O$$_2$ or to menadione. The highest $IC_{50}$/ values for DPPH radical scavenging activity was found in the ethyl acetate fraction with a value of 5.38 $\mu\textrm{g}$/mL. Cells pretreated with $\geq$ 1 $\mu\textrm{g}$/mL of the ethyl acetate extract had significantly increased cell viability compared to control cells, which were not pretreated with the extract. Intracellular ROS formation and DNA damage in HepG$_2$ cells, which were pretreated with the various concentrations of Rhus javanica ethyl acetate extract and then incubated either with $H_2O$$_2$ or with menadione, reduced in a dose-dependent manner. These findings suggest that Rhus javanica might have biologically active components which have strong protective effects against ROS induced oxidative damages to the biomolecules, such as cell membranes and DNA.