• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1997년도 학술발표회
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• pp.15-15
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• 1997

Recent studies indicate that hydrogen peroxide (H$_2$O$_2$), which is one of the reactive oxygen species involved in the oxidative stress, is an intracellular secondary messenger in the signal transduction. A novel family of thiol specific antioxidant (TSA) enzymes with a peroxidase activity shows no sequence homology to previously known antioxidant enzymes.(omitted)

• Toxicological Research
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• 제17권
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• pp.299-304
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• 2001

Xenobiotics and their reactive intermediates bind to cellular macromolecules and/or generate oxidative stress. which provoke deleterious effects on the cell function. Induction of xenobiotic-biotrans-forming enzymes and antioxidant molecules is an important defense mechanism against such insults. A group of genes involved in the defense mechanism. e.g. genes encoding glutathione S-transferases. NAD(P)H: quinone oxidoreductase, UDP-glucuronosyltransferase (UDP-GT) and ${\gamma}$-glutamylcysteine synthetase (GGCS). have a common regulatory sequence, Antioxidant or Electrophile Responsive Element (ARE/EpRE). Recently. Nrf2. discovered as a homologue of erythroid transcription factor p45 NF-E2, was shown to bind ARE/EpRE and induce the expression of these defense genes. Mice that lack Nrf2 show low basal levels of expression and/or impaired induction of these genes. which makes the animals highly sensitive to xenobiotic toxicity. Indeed. we show here that nrf2-deficient mice had a higher mortality than did the wild-type mice when exposed to acetaminophen (APAP). Detailed analyses of APAP hepatotoxicity in the nrf2 knockout mice indicate that a large amount of reactive APAP metabolites was generated in the livers due to the impaired basal expression of two detoxifying enzyme genes, UDP-GT (Ugt1a6) and GGCS. while the cytochrome P450 content was unchanged. Thus. the studies using the nrf2 knockout mice clearly demonstrate significance of the expression of Nrf2-regulated enzymes in protection against xenobiotic toxicity.

• Journal of Applied Biological Chemistry
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• 제57권1호
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• pp.17-22
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• 2014

Nardostachys chinensis (N. chinensis) has been used in traditional medicine as a sedative and analgesic. It has been reported that N. chinensis extract has an antioxidant activity. However, the mechanism has not been elucidated. In this study, we showed that FOXO3a was activated by N. chinensis extract. FOXO3a is a transcriptional factor that involved in cell cycle arrest, DNA repair, apoptosis, and detoxification of reactive oxygen spices (ROS). Protein level of FOXO3a was increased by N. chinensis extract whereas phospho-FOXO3a (Thr 32) was not changed. Promoter activities of target genes of FOXO3a such as MnSOD, p27, and GADD45 were increased by N. chinensis extract. Among target genes, protein level of MnSOD was increased by N. chinensis extract, and this leads to removal of ROS level in human embryonic fibroblast (HEF) cells. These results suggested that N. chinensis extract has an antioxidant activity by upregulation of MnSOD through FOXO3a activation.

• Natural Product Sciences
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• 제19권1호
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• pp.49-53
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• 2013

Paeonia lactiflora Pall (PL) has been used as a traditional herbal medicine in China, Korea, and Japan for more 1,200 years. PL has reported to have antioxidant activity and protective effect of cells from oxidative stress, although the mechanism has not been verified. FOXO3a is a transcription factor that binds to its target gene's consensus FOXO binding site. FOXO3a protein modulates the various biological functions including cell cycle control, apoptosis, DNA repair, and ROS detoxification. Therefore, FOXO3a activity is associated with cancer, aging, diabetes, infertility, neurodegeneration, and immune system dysfunction. Here we found that FOXO3a was activated by PL extract. Transcriptional target genes such as MnSOD, p27, and GADD45 were activated by PL extract. Protein levels of MnSOD and catalase were increased, consequently, ROS level was reduced in HEF cells by PL extract. These findings suggest that PL extract has an antioxidant activity through FOXO activation and thereby activation of FOXO target genes, MnSOD and catalase.

• 한국약용작물학회지
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• 제21권2호
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• pp.136-141
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• 2013

Chelidonium majus (CM) contains several isoquinoline alkaloids that have been reported to have various biological activities such as anti-inflammatory, antimicrobial, antioxidant, immune-modulatory, and antitumoral. It has been reported that the extract of CM had an antioxidant potential, however the mechanism has not been verified. In this study, we found that CM extract activated FOXO3a. FOXO3a is a transcription factor that involved in various biological processes such as cell cycle arrest, apoptosis, DNA repair, and ROS detoxification. Transcriptional activities of FOXO3a were regulated by post-translational modifications including phosphorylation, acetylation, and ubiquitination. Protein level of FOXO3a was increased by CM extract. Promoter activities of FOXO-transcriptional target genes such as MnSOD, p27 and GADD45 were activated by CM extract in a dose dependent manner. In addition, protein level of MnSOD, major antioxidant enzyme, was increased by CM extract. Thereby ROS level was decreased by CM in old HEF cells. These results suggest that CM extract has an antioxidant activity through FOXO activation.

• The Korean Journal of Pain
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• 제36권1호
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• pp.72-83
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• 2023

Background: Globally, spinal cord injury (SCI) results in a big burden, including 90% suffering permanent disability, and 60%-69% experiencing neuropathic pain. The main causes are oxidative stress, inflammation, and degeneration. The efficacy of the stem cell secretome is promising, but the role of human neural stem cell (HNSC)-secretome in neuropathic pain is unclear. This study evaluated how the mechanism of HNSC-secretome improves neuropathic pain and locomotor function in SCI rat models through antioxidant, anti-inflammatory, anti-matrix degradation, and neurotrophic activities. Methods: A proper experimental study investigated 15 Rattus norvegicus divided into normal, control, and treatment groups (30 µL HNSC-secretome, intrathecal in the level of T10, three days post-traumatic SCI). Twenty-eight days post-injury, specimens were collected, and matrix metalloproteinase (MMP)-9, F2-Isoprostanes, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, and brain derived neurotrophic factor (BDNF) were analyzed. Locomotor recovery was evaluated via Basso, Beattie, and Bresnahan scores. Neuropathic pain was evaluated using the Rat Grimace Scale. Results: The HNSC-secretome could improve locomotor recovery and neuropathic pain, decrease F2-Isoprostane (antioxidant), decrease MMP-9 and TNF-α (anti-inflammatory), as well as modulate TGF-β and BDNF (neurotrophic factor). Moreover, HNSC-secretomes maintain the extracellular matrix of SCI by reducing the matrix degradation effect of MMP-9 and increasing the collagen formation effect of TGF-β as a resistor of glial scar formation. Conclusions: The present study demonstrated the mechanism of HNSC-secretome in improving neuropathic pain and locomotor function in SCI through antioxidant, anti-inflammatory, anti-matrix degradation, and neurotrophic activities.

• 한국산학기술학회논문지
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• 제6권4호
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• pp.285-290
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• 2005

고무제품의 기계적 특성은 혼합물 성분, 경화 상태 공정 및 충진제 같은 많은 요소에 기인된다. 우리 연구의 목적은 N-isopropyl-N'-chloro-P-phenylene diamine, 항산화제의 영향을 열적 상태에서 노화 및 오존 균열에 관해 조사하였다. 이 연구에서 항미생물 고무매트의 퇴화가 연구되었는데, 항산화제 함유 및 항산화제가 함유되지 않은 항균매트에 관한 열적 상태의 노화 및 오존 균열을 조사하였다.

• 한국자원식물학회지
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• 제19권6호
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• pp.670-676
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• 2006

Tea polysaccharide had high antioxidant activity and it could be used to cure diabetes. Antioxidant activity of tea poly-saccharide (TPS) from three kinds of tea (green tea, oolong tea and black tea) were compared, the result indicated that oolong tea polysaccharide (OTPS) had the highest antioxidant activity. In order to explicate the mechanism of antioxidant and hypoglycemic activity, the streptozotocin (STZ)-induced diabetes mice model (DM) was established. The influence of OTPS on blood-glucose, content of MDA and NO, and activities of GSH-PX, SOD, NOS in serum, kidney and liver were investigated. The result showed that after four weeks injection of OTPS to DM mice, the blood-glucose of three treatment group reduced by 14.5%,21.5% and 33.3%, respectively, comparing to the model control. The reduction effect of OTPS increased with the rise of dose. The activity of SOD and GSH-PX elevated significantly, while the activity of NOS decreased. The content of MDA and NO reduced significantly. The above results imply that antioxidant activity was enhanced. Comparing to XKW treatment, the effect of a dose of 300mg/(kg. bw) OTPS was much better. The research showed that the OTPS had a significant effect on reducing blood glucose, and could enhance the antioxidant activity of DM mice.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1633-1638
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• 2014

[6]-Gingerol is known as the major bioactive constituent of ginger. In the study, it was observed to effectively protect against ${\bullet}OH$-induced DNA damage ($IC_{50}$ $328.60{\pm}24.41{\mu}M$). Antioxidant assays indicated that [6]-gingerol could efficiently scavenge various free radicals, including ${\bullet}OH$ radical ($IC_{50}$ $70.39{\pm}1.23{\mu}M$), ${\bullet}O_2{^-}$ radical ($IC_{50}$ $228.40{\pm}9.20{\mu}M$), $DPPH{\bullet}$radical ($IC_{50}$ $27.35{\pm}1.44{\mu}M$), and $ABTS{^+}{\bullet}$radical ($IC_{50}$ $2.53{\pm}0.070{\mu}M$), and reduce $Cu^{2+}$ ion ($IC_{50}$ $11.97{\pm}0.68{\mu}M$). In order to investigate the possible mechanism, the reaction product of [6]-gingerol and $DPPH{\bullet}$ radical was further measured using HPLC combined mass spectrometry. The product showed a molecular ion peak at m/z 316 $[M+Na]^+$, and diagnostic fragment loss (m/z 28) for quinone. On this basis, it can be concluded that: (i) [6]-gingerol can effectively protect against ${\bullet}OH$-induced DNA damage; (ii) a possible mechanism for [6]-gingerol to protect against oxidative damage is ${\bullet}OH$ radical scavenging; (iii) [6]-gingerol scavenges ${\bullet}OH$ radical through hydrogen atom ($H{\bullet}$) transfer (HAT) and sequential electron (e) proton transfer (SEPT) mechanisms; and (iv) both mechanisms make [6]-gingerol be oxidized to semi-quinone or quinone forms.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.345-350
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• 2011

Antioxidant agent, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane were prepared and investigated the antioxidant activity on recycled rubber mat manufactured with waste tire powder. Mechanical properties of rubber mat are influenced by many factor such as compounding ingredients and state of cure, process of rubber, and fillers. Our study aim is to investigate influence of antioxidant activities on ozone cracking and the thermal aging time. In this work, the degradation of recycled rubber mat was studied and suggested mechanism to involve two-type of degradation, thermal aging and cracking both of which can be contained antioxidant or non-antioxidant agent.