• Journal of Photoscience
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• v.9 no.2
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• pp.424-426
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• 2002

Recently, much attention has been paid to the physiological functions of flavonoids associated with their antioxidant properties. However, there was a lack of information on the molecular mechanism at which flavonoids play the antioxidative role. We have already studied on the oxidation of quercetin with hydrogen peroxide and sodium hypochlorite in alcoholic aqueous solution and determined the oxidation products. Through the structural analysis of the oxidation products, it was clarified that the hydroxyl group at C-3 in the C ring plays the important role in the antioxidative action of quercetin. Successively, rutin and (+)-catechin were oxidized with sodium hypochlorite and their mono- and di-chlorinated derivatives were obtained. These facts indicate that these flavonoids can directly scavenge hypochlorous acid and the active site in this scavenging reaction is not the hydroxyl group at C-3.

• Korean Journal of Acupuncture
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• v.27 no.2
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• pp.13-24
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• 2010

Objectives : Ulcerative colitis is a chronic relapsing inflammatory disease in the gastrointestinal tract. We investigated whether Aurantii fructus immaturus (AFI) pharmacopuncture has antioxidative and anti-inflammatory effects. Methods : in vitro experiments, 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging activity, superoxide dismutase (SOD) activity, prevention on $H_2O_2$-induced cell death in RAW264.7 cell line, DNA fragmentation, and cyclooxygenase-2 mRNA expression induced by lipopolysaccharide (LPS), were analyzed to investigate antioxidative and anti-inflammatory effect of AFI pharmacopuncture. in vivo experiment, a murine model of dextran sulfate sodium (DSS)-induced colitis was used to examine the effect of AFI pharmacopuncture on CV12 at different doses of 5 ${\mu}l$, 0.5 ${\mu}l$, 0.05 ${\mu}l$ for 10 days. Body weight, colon length and macroscopic features were investigated. Results : AFI pharmacopuncture showed DPPH free radical scavenging and SOD active effects in a dose-dependent manner. AFI pharmacopuncture showed a protective effect against $H_2O_2$-induced cell injury and also attenuated LPS-induced COX-2 mRNA expression. In a DSS- induced colitis murine model, however, AFI pharmacopuncture at CV12 had no anti-inflammatory effects. Conclusions : The present results suggest that AFI pharmacopuncture extract may have anti- inflammatory and antioxidative effects in vivo test, but further research on the underlying mechanism is required.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.49-50
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• 2003

• Biomedical Science Letters
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• v.20 no.2
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• pp.56-61
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• 2014

This study attempted to confirm the antioxidative potential of luteolin against tert-butyl hydroperoxide (t-BHP) induced oxidative damage and to investigate its molecular mechanism related to glutathione (GSH)-dependent enzymes in HepG2 cells. Treatment with luteolin resulted in attenuation of t-BHP induced generation of reactive oxygen species (ROS) and oxidative stress-mediated cell death. In addition, accelerated expression of GSH-dependent antioxidative enzymes, glutathione peroxidase (GPx) and glutathione reductase (GR), and heme oxygenase (HO)-1, as well as strengthened GSH content was induced by treatment with luteolin, which was in accordance with increased nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), a transcription factor for phase 2 enzymes, in a dose-dependent manner. These results suggest that the cytoprotective potential of luteolin against oxidative damage can be attributed to fortified GSH-mediated antioxidative pathway and HO-1 expression through regulation of Nrf2 in HepG2 cells.

• Journal of Life Science
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• v.6 no.1
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• pp.48-55
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• 1996

Oxygen free radicals are highly reactive molecules with unpaired electrons, which are produced with in aerobic cells in the course of normal metabolic events. Normally, aerobic cells are protected from the damage of free radicals by antioxidative enzymes such as superoxide dismutase (SOD), catalase, glutathione (GSH) peroxidase, GSH S-transferase and GSH reductase which scabvenge free radicals as well as nonenzymatic antioxidants such as ceruloplasmin, albumin and nontioxidants in order to elucidate antioxidative mechanisms of red ginseng. The treatment with total saponin of red ginseng significantly devreased the contents of malondialdehyde and total free radicals in the liver. On the other hand, total saponin of red ginseng significantly increased the activities of SOD, catalase and GSH reductase and nonprotein-SH level. These results suggest that total saponin of red ginseng exerts an antioxidative effect by increasing endogenous antioxidants.

• Journal of Life Science
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• v.13 no.5
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• pp.658-667
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• 2003

Antioxidative enzymes (superoxide dismutase; SOD, ascorbate peroxidase; APX, glutathione reductase; GR) play major roles in scavenging mechanism of reactive oxygen species which were involved in various stress conditions including salt. In order to investigate the relation between their growth responses (dry weight) and the changes of antioxidative enzymes activity, salt-tolerant spinach beet having 15cm of shoot length were treated with various salt levels (0, 50, 200, 1000 mM NaCl) for 24 hours. Spinach beet exhibited an increase in the activity of antioxidative enzymes by salt, the maximal activity at 200 mM NaCl and the lowest activity at 50 mM NaCl in 2 hrs. after treatments. As a result of PAGE, it has been confirmed that spinach beet contained 3 isoforms (Fe-SOD, CuZn-SOD and Mn-SOD) of SOD and main isoform was CuZn- SOD form. In case of APX, isoforms of the low molecular weight(No. 7, 8) were showed strong expression especially at 200 and 400 mM NaCl treatment. Meanwhile, GR did not show specific pattern of isoforms among the salt treatments. Especially, in case of 50 mM treatment, plant showed the lowest activity of SOD with the best growth, a low enzyme activity was induced by inactivation of the Mn-SOD. Therefore, we suggested that the decrease of SOD activity at a low salt level (50 mM NaCl) or the increase of enzyme activity at a high salt level (200 mM NaCl) may be related to expression of the Mn-SOD isoform. These antioxidative enzymes showed the increase of activity in a short time by salt addition. So, it is considered that spinach beet copes effectively with a stressful condition such as salt by operating effective antioxidative defense mechanism rapidly under high salt level.

• Biomedical Science Letters
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• v.24 no.4
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• pp.357-364
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• 2018

Manganese (Mn) is used as main materials in various chemical processes of industry, but it suggested that Mn brings about its toxicant by fume or dust through respiratory system and skin barrier. Mn toxicant induces the loss of mental health and life quality by cerebrovascular and skin diseases. Nevertheless, it lefts much unknown on the mechanism and the effectively therapeutic methods about Mn toxicant. Therefore, this study was evaluated the cytotoxicity induced by manganese dioxide ($MnO_2$) in cultured NIH3T3 fibroblasts, and also, the correlation between $MnO_2$-induced cytotoxicity and oxidative stress was examined. While, the effect of Eclipta prostrata L. (EP) extract belong to Compositae was assessed against $MnO_2$-induced cytotoxicity in the view of antioxidative effect for searching the natural resources mitigating or preventing the $MnO_2$-induced cytotoxicity. In this study, $MnO_2$-induced cytotoxicity was revealed as mid-toxic by Borenfreud and Puerner's toxic criteria, and catalase (CAT), an antioxidant prevented $MnO_2$-induced cytotoxicity by the remarkable increase of cell viability in these cultures. While, in the protective effect of EP extract on $MnO_2$-induced cytotoxicity, EP extract effectively prevented the cytotoxicity induced by $MnO_2$ via antioxidative effects such as xanthine oxidase (XO) inhibitory ability and DPPH-radical scavenging ability. From the above results, EP extract showed the effective prevention against $MnO_2$-induced cytotoxicity correlated with oxidative stress by antioxidative effects. Conclusively, this study may be useful to research or development the alternatively therapeutic agent from natural resources like EP extract for the treatment of diseases resulted in oxidative stress.

• Herbal Formula Science
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• v.6 no.1
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• pp.215-226
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• 1998

Geagibokrounghwan (桂技茯笭湯) has long been used to cure human diseases such as vascular and blood disorders. However, it is still unkown on its action mechanism, physiolosical and biochemical meaning. Thus, many attempts were tried to show the scientific background covering the above mentioned mechanism. The effect of Geagibokrounghwan, which was known to date, as follow; effective circulation of body blood system, proliferation of leucocytes and antioxidative action. In this study, we have applied the Geagibokrounghwan administration and feed to mouse, to see effects on the expression of superoxide dismutase(SOD) mRNA as antioxidative agent and oxygen radical scavenger. Total RNAs includingmRNA have been isolated from liver and white blood cells after mice were fed with cholesterol in high dose. Also, in a separate group, the cholesterol-administrated mice were fed with Geagibokrounghwan to see the effects on SOD transcription. and then reverse transcriptase-polymerase chain reaction (RT-PCR) usion each primer set (SOD-F;GATGAAAGCGGTGT-3'; SOD-R; 5'-CCTGTGGAGTGATT-3') were performed to trace theamounts of mRNA. SOD mRNA was specifically expressed in Geagibokrounghwan-fed mice at 2 weeks after treatment, however, gradually reduced after 4 weeks. These results indicate that Geagibokrounghwan is highly applicable in treatment of the above mentioned human diseases.

• Natural Product Sciences
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• v.10 no.4
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• pp.182-189
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• 2004

To find the action mechanism of the MeOH extract (LFS) of Ligularia fischeri var. spiciformis herbs (Compositae) and its active component, 3,4-dicaffeoylquinic acid (DCQA) on antihepatotoxicity, the effect was investigated on hepatic lipid perxodation and drug-metabolizing enzyme activities in acetaminophen-treated rat. Pretreatment with 250 mg/kg LFS (p.o.) and 10 mg/kg DCQA (p.o.) significantly decreased hepatic lipid peroxidation caused by acetaminophen injection. Further, LFS and DCQA inhibited hepatic microsomal enzyme activation such as hepatic P-450 cytochrome $b_5$, aniline hydroxylase and aminopyrine N-demethylase, suggesting that the two substances might effectively prevent the metabolic activation or scavenge electrophilic intermediates capable of causing hepatotoxicity. Both LFS and DCQA increased hepatic glutathione content and glutathione reductase activity, indicating that both resultantly prevented hepatotoxicity via antioxidative mechanism. Therefore, it was found that LFS had antihepatotoxicity based on the antioxidative action of DCQA.

• Archives of Pharmacal Research
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• v.29 no.2
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• pp.165-171
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• 2006

Osteoarthritis is thought to be induced by the ageing-related loss of homeostatic balance between degeneration and repair mechanism around cartilage tissue in which inflammatory mediators such as reactive oxygen species, cytokines and prostaglandins are prone to overproduction under undesirable physiological conditions. Phlorotannins are unique polyphenolic compounds bearing dibenzo-1,4-dioxin skeleton which are not found in terrestrial plants but found only in some brown algal species such as Ecklonia and Eisenia families. Phlorotanninrich extracts of Ecklonia cava including LAD103 showed significant antioxidant activities such as DPPH radical scavenging, ferric ion reduction, peroxynitrite scavenging, and inhibition of LDL oxidation, indicating their possible antioxidative interference both in onset and downstream consequences of osteoarthritis. LAD103 also showed significant down regulation of $PGE_2$ generation in LPS-treated RAW 246.7 cells, and significant inhibition of human recombinant interleukin-$1{\alpha}$-induced proteoglycan degradation, indicating its beneficial involvement in pathophysiological consequences of osteoarthritis, the mechanism of which needs further investigation. Since LAD103 showed strong therapeutic potentials in arthritic treatment through several in vitro experiments, it is highly encouraged to perform further mechanistic and efficacy studies.