• Title/Summary/Keyword: Radical mechanism

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Peroxiredoxins and the Regulation of Cell Death

  • Hampton, Mark B.;O'Connor, Karina M.
    • Molecules and Cells
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    • v.39 no.1
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    • pp.72-76
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    • 2016
  • Cell death pathways such as apoptosis can be activated in response to oxidative stress, enabling the disposal of damaged cells. In contrast, controlled intracellular redox events are proposed to be a significant event during apoptosis signaling, regardless of the initiating stimulus. In this scenario oxidants act as second messengers, mediating the post-translational modification of specific regulatory proteins. The exact mechanism of this signaling is unclear, but increased understanding offers the potential to promote or inhibit apoptosis through modulating the redox environment of cells. Peroxiredoxins are thiol peroxidases that remove hydroperoxides, and are also emerging as important players in cellular redox signaling. This review discusses the potential role of peroxiredoxins in the regulation of apoptosis, and also their ability to act as biomarkers of redox changes during the initiation and progression of cell death.

Effects of Nitrofurantoin on Lipid Peroxidation and Reactive Oxygen Radical Generation in Porcine Lung Microsome (Nitrofurantion이 폐장 미크로솜 지질과산화와 반응성 산소 라디칼 생성에 미치는 영향)

  • Paick, Jae-Seung;Kim, Si-Whang;Kim, Hae-Won;Chung, Myung-Hee;Kim, Myung-Suk
    • The Korean Journal of Pharmacology
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    • v.21 no.1
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    • pp.34-48
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    • 1985
  • In vitro effects of nitrofurantoin, an antimicrobial agent for acute and chronic urinary tract infection, on the lung microsomal lipid peroxidation and the generation of reactive oxygen radicals were investigated to elucidate the biochemical mechanisms of its in vivopulmonary toxicity. The interaction of nitrofurantoin with porcine lung microsome resulted in significant lipid peroxidation. In addition, nitrofurantoin stimulated the generation of reactive oxygen radicals, $O^{-}_{2}{\cdot},\;H_2O_2$ as well as a highly reactive secondary oxygen species, $OH{\cdot}$. The stimulation of lipid peroxidation was inhibited not only by superoxide dismutase and catalase, but also by hydroxyl radical scavengers, mannitol and thiourea. Neither singlet oxygen $({^1}O_{2})$ was detected during the incubation of microsome with nitrofurantoin, nor lipid peroxidation was inhibited by singlet oxygen scavengers. When incubated anaerobically under the nitrogen atmosphere, the ability of nitrofurantoin to stimulatle lipid peroxidation was abolished. It appears that NADPH-dependent metaboliam of nitrofurantoin in pulmonary microsome under aerobic condition is accompanied by the stimulation of lipid peroxidation through the mediation of reactive oxygen radicals, particularly hydroxyl radical. It is strongly suggested from these results that the stimulation of pulmonary microsomal lipid peroxidation by the reactive oxygen radical may be a in vivo mechanism of pulmonary toxicity caused by nitrofurantoin.

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Elementary Student's and Teacher's Views on Life Phenomenon (초등학교 학생과 교사의 생명 현상을 보는 관점)

  • Lee, So-Hee;Shin, Young-Joon
    • Journal of Korean Elementary Science Education
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    • v.26 no.1
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    • pp.108-116
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    • 2007
  • The purpose of this study was to examine the views of elementary students and teachers in relation to life phenomenon. Students seemed to strongly agree with the notion of vitalism as well as with organicism. However they clearly disagreed with the notion of mechanism. Contrary to our supposition, their viewpoints on lift phenomenon were highly affected by their relative levels of academic achievement in science subject areas, rather than by their religious affiliations. One possible explanation for this outcome is that elementary schoolers have not firmly established religious views, though they might indeed have a religious affiliation. High-achieving children in science subject areas seemed to agree with both vitalism and organicism (p<.01), and it is suggested that those students must have had more opportunities to encounter related cases in modem science or life ethics. Teachers agreed with all three views, showing the highest rate of approval in organicism. Though they appeared to agree with mechanism, they were strongly opposed to radical mechanism generally arguing that 'organism and machines were essentially the same'. Student responses indicated that TV had a bigger influence on their viewpoint on life phenomenon than teachers did. This means that children held certain views about the relative significance and influences of teachers vis-a-vis TV in daily life, and is also reflective of a perception amongst students that teachers do not how the significance of viewpoints on lift phenomenon.

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A Study on the Effect and Mechanism of Gamikyejakjimogawusul-tang Herbal Acupuncture on Induced Rheumatoid Arthritis model of DBA/1 mice (계작지모가우슬탕(桂芍知母加牛膝湯) 약침이 류마티스 관절염 생쥐에 미치는 영향)

  • Jung, Soon Hyun;Cho, Chong kwan;Kim, So Yun;Kim, Young Il
    • Journal of Haehwa Medicine
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    • v.24 no.2
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    • pp.35-57
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    • 2016
  • Objectives : The purpose of this study is to prove the effect and mechanism of Gamikyejakjimogawusul-tang(GKHA) herbal acupuncture on induced rheumatoid arthritis model of DBA/1 mice. Methods : We check effect of GKHA extract on the AST, ALT, Creatinine, BUN of serum and cell viability of GK extract in RAW 264.7 cells to test the stability of this study. In vitro, we measure total phenol contents, total flavonoid contents, DPPH free radical scavenging activity, ABTS cation radical scavenging activity of Gamikyejakjimogawusul-tang, effect of GK extract on ROS(Reactive Ooxygen Species) production to estimate a anti-oxidant capacity, and we also measure effect of GK extract on NO (Nitric Oxid), IL-$1{\beta}$, IL-6, IL-17, IL-21, TNF-${\alpha}$, MCP-1, GM-CSF production in RAW 264.7 cells to estimate a anti-inflammatory efficacy. In vivo, we compare a rheumatoid arthritis manifestation between control and experimental group and estimate a AI. Then we check effect of GKHA on the level of WBC, neutrophil, lympocyte, monocyte in the blood to see the effect of immune cells in blood. In addition we measure effect of GKHA on the level of hs-CRP, IgM, IgG, IL-$1{\beta}$, IL-6, IL-17, IL-21, TNF-${\alpha}$, MCP-1, GM-CSF in serum. We observe effects of GKHA on imaging of cartilage degeneration using micro CT-arthrography in paw hind. And we calculate effects of GKHA that reduced BV ratio, BS/BV ratio using 3D Micro-CT. Lastly we observe effects of GKHA histopathologic examination analysis. Results : 1. The toxicity on liver and kidney was disregardable and the cytotoxicity against RAW 264.7 cells was also disregardable. 1. Total phenol contents and total flavonoid contents in GK extract were in high level. 2. DPPH free radical scavenging activity and ABTS cation radical scavenging activity were increased according to concentration of GK extract 3. ROS production was significantly decreased in GK extract (at 10, $100{\mu}g/ml$). 4. NO, IL-6, TNF-${\alpha}$, MCP-1 production were significantly decreased in GK extract(at 10, $100{\mu}g/ml$). IL-17, GM-CSF production were significantly decreased in GK extract(at 1, 10, $100{\mu}g/ml$). IL-$1{\beta}$, IL-21 production were also decreased but there was no statistical significance. 5. 25x observation after H&E and M-T staining, infiltration of immune cells and subsidence of the cartilage and damage to the synovial cells were decreased. Conclusions : This study showed that GKHA extract had anti-oxidant capacity, anti-inflammatory efficacy. GKHA extract also had inhibiting effect on the process of rheumatoid arthritis and can protect joint and cartilage. So we expect that GKHA extract can be a meaningful treatment to rheumatoid arthritis patients.

L-lysine and L-arginine inhibit the oxidation of lipids and proteins of emulsion sausage by chelating iron ion and scavenging radical

  • Xu, Peng;Zheng, Yadong;Zhu, Xiaoxu;Li, Shiyi;Zhou, Cunliu
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.6
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    • pp.905-913
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    • 2018
  • Objective: To evaluate the effects of L-lysine (Lys)/L-arginine (Arg) on lipid and protein oxidation of emulsion sausage during storage and its possible mechanism. Methods: Four samples were prepared based on the presence or absence of additional sodium isoascorbate, Lys, or Arg: sample A (control), sample B (0.05 g of sodium isoascorbate), sample C (0.4 g of Lys), and sample D (0.4 g of Arg). Peroxide value (POV), thiobarbituric reactive substances (TBARS), protein carbonyls and thiols were measured. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical-scavenging, ferrous ion-chelating ability were also measured. Results: Compared with the control, the sample treated with sodium isoascorbate, Lys or Arg had significantly lower POV during the initial 20 days, TBARS during the initial 15 days. Protein carbonyls were significantly lower compared Sample B, C, and D with A during the later storage (10 to 25 days); basically, protein thiols became lower during storage when the samples were treated with sodium isoascorbate, Lys, or Arg. Both Lys and Arg had weak reducing power but strong ferrous ion-chelating activity and DPPH radical- and hydroxyl radical-scavenging activity. Conclusion: Both Lys and Arg effectively inhibited the oxidation of lipids and proteins in emulsion sausage by scavenging free radicals and chelating ferrous ions. The results obtained may be favorable for the prevention of lipid and protein oxidation during processing and storage of meat products.

A Study for Oxidants Generation on Oxygen-plasma Discharging Process Discharging System (산소-플라즈마 공정에서 산화제의 생성에 대한 연구)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.22 no.12
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    • pp.1561-1569
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    • 2013
  • This study carried out a laboratory scale plasma reactor about the characteristics of chemically oxidative species (${\cdot}OH$, $H_2O_2$ and $O_3$) produced in dielectric barrier discharge plasma. It was studied the influence of various parameters such as gas type, $1^{st}$ voltage, oxygen flow rate, electric conductivity and pH of solution for the generation of the oxidant. $H_2O_2$ and $O_3$.) $H_2O_2$ and $O_3$ was measured by direct assay using absorption spectrophotometry. OH radical was measured indirectly by measuring the degradation of the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical). The experimental results showed that the effect of influent gases on RNO degradation was ranked in the following order: oxygen > air >> argon. The optimum $1^{st}$ voltage for RNO degradation were 90 V. As the increased of $1^{st}$ voltage, generated $H_2O_2$ and $O_3$ concentration were increased. The intensity of the UV light emitted from oxygen-plasma discharge was lower than that of the sun light. The generated hydrogen peroxide concentration and ozone concentration was not high. Therefore it is suggested that the main mechanism of oxidation of the oxygen-plasma process is OH radical. The conductivity of the solution did not affected the generation of oxidative species. The higher pH, the lower $H_2O_2$ and $O_3$ generation were observed. However, RNO degradation was not varied with the change of the solution pH.

Study on the Effect of Gamisihotang(GSHT) on Glutamate Receptor, Free Radical and Brain Damage in Rats Subjected to Brain Ischemia (가미시호탕이 뇌허혈시 Glutamate receptor, free radical 및 뇌손상 보호에 미치는 영향)

  • Oh Byung-Yul;Kim Min-Sang;Yu Byeong-Chan;Choi Young;Seol In-Chan
    • The Journal of Korean Medicine
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    • v.25 no.3
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    • pp.32-44
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    • 2004
  • Objectives : This study was undertaken to prove the effect of GSHT on the glutamate receptor, free radical and brain damage in rats subjected to brain ischemia Methods : Levels of cultured cortical neuron death caused by toxic chemicals were measured by LDH release assay. Neuroprotective effects of GSHT on brain tissues were examined in vivo by ischemic model of middle cerebral artery (MCA) occlusion. Results : GSHT showed significant inhibitory effect on LDH release induced by NMDA-kinate-Fe/sup 2+/. GSHT remarkably decreased coma duration time in a nonfatal dose of KCN and showed higher survival rate in a fatal dose. GSHT remarkably decreased ischemic area and edema induced by the MCA blood flow block. GSHT showed high improvement of forelimb and hind limb test after MCA occlusion in neurological examination. GSHT showed no significant change after MCA occlusion in pathological observation of the normal group. Conclusions : These results indicate that GSHT can be used to treat the brain damage caused by brain ischemia. Further study will be needed about the functional mechanism, etc.

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Protective Effect of Rehmannia Radix Preparata Extract on the Cisplatin-induced Cytotoxicity of HEI-OC1 Cells via Scavenging of Free Radicals (숙지황 추출물이 Cisplatin으로 손상된 HEI-OC1 세포보호와 유리라디칼 소거능에 미치는 영향)

  • Yu Hyeon-Hee;Seo Se-Jeong;Kim Yeon-Hwa;Park Rae-Kil;So Hong-Seob;Jeon Byung-Hun;Shin Mee-Kyung;Jung Su-Young;Kim Ki-Young;You Yong-Ouk
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.5
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    • pp.1349-1355
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    • 2005
  • The steamed root of Rehmannia glutinosa has been used for treatment of inner ear diseases, such as tinnitus and hearing loss in traditional Oriental Medicine. In the present study, we investigated the effect of ethanol extract of steamed root R. glutinosa (SRG) on cisplatin cytotoxicity of HEI-OC1 auditory cells. In addition, to investigate the mechanism of SRG on cisplatin cytotoxicity, the effects of SRG on lipid peroxidation as well as scavenging activities against various free radicals were measured in cisplatin-treated cells. Treatment of SRG protected cells from cisplatin and reduced lipid peroxidation in a dose-dependent manner. Furthermore, SRG demonstrated significant scavenging activity against various free radicals, including superoxide radical, hydroxyl radical, hydrogen peroxide, and DPPH radical. These results indicate that SRG protects cisplatin-induced damages of HEI-OC1 cells through inhibition of lipid peroxidation and augmenting scavenging activities against free radials.

Protective Effect of Pueraria Radix Extract on the Cisplatin-induced Cytotoxicity of HEI-OC1 Cells Via Scavenging of Free Radicals (갈근 추출물이 Cisplatin으로 손상된 HEI-OC1 청각세포보호와 유리라디칼 소거능에 미치는 영향)

  • Yu, Hyeon-Hee;Seo, Se-Jeong;Moon, Hae-Dalma;Park, Rae-Kil;So, Hong-Seob;Jeon, Byung-Hun;Jung, Su-Young
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.2
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    • pp.462-467
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    • 2007
  • The radix of Pueraria thunbergiana BENTHAM (Leguminosae) is traditionally prescribed to attenuate the clinical manifestations of inner ear dysfunction and various clinical situations including fever, gastrointestinal disorders, skin problems, migraine headaches, lowering cholesterol and treating chronic alcoholism in Oriental Medicine. In the present study, we examined the effect of ethanol extract of P. thunbergiana radix (EPR) on cisplatin-mediated HEI-OC1 auditory cell death. In addition, to investingate the protection mechanism of EPR on free radicals. Treatment of EPR protected cells from cisplatin and reduced lipid peroxidation in a dose-dependent manner. Furthermore, EPR demonstrated significant scavenging activity against various free radicals, including superoxide radical, hydroxyl radical, hydrogen peroxide, and DPPH radical. These results indicate that EPR protects cisplatin-induced damages of HEI-OC1 cells through inhibition of lipid peroxidation and augmenting scavenging activities against free radials.

Antioxidant and Whitening Effects of Agrimonia pilosa Ledeb Water Extract (짚신나물 물 추출물의 항산화 활성 및 미백효과에 관한 연구)

  • Kim, Tae-Hyuk;Kim, Jeong-Mi;Baek, Jong-Mi;Kim, Tae-Woo;Kim, Dae-Jung;Park, Jeong-Hae;Choe, Myeon
    • Korean Journal of Medicinal Crop Science
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    • v.19 no.3
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    • pp.177-184
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    • 2011
  • This study was performed to assess the antioxidant activities and whitening effects of Agrimonia pilosa Ledeb on melanin synthesis. The whitening effects of Agrimonia pilosa Ledeb water extracts were examined by in vitro mushroom tyrosinase assay and B16BL6 melanoma cells. We assessed inhibitory effect of Agrimonia pilosa Ledeb water extract on expression of melanogenic enzyme proteins including tyrosinase, tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2 (TRP-2) in B16BL6 cells. Inhibitory effect of Agrimonia pilosa Ledeb onto free radical generation was determined by measuring DPPH and hydroxyl radical scavenging activitie. Our results indicated that Agrimonia pilosa Ledeb water extract effectively inhibited free radical generation. In DPPH and hydroxy radical scavenging activity, Agrimonia pilosa Ledeb water extract had a potent anti-oxidant activity in a dose-dependent manner. They significantly inhibited tyrosinase activity in vitro and in B16BL6 melanoma cells. Also, Agrimonia pilosa Ledeb suppressed the expression of tyrosinase in B16BL6 melanoma cells. These results show that Agrimonia pilosa Ledeb inhibited melanin production on the melanogenesis. The underlying mechanism of Agrimonia pilosa Ledeb on whitening activity may be due to the inhibition of tyrosinase activity. We suggest that Agrimonia pilosa Ledeb may be useful as new natural active ingredients for antioxidant and whitening cosmetics.