• Title/Summary/Keyword: oxygen inhibition

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Antioxidant and Acetylcholinesterase Inhibition Activity of Mulberry Fruit Extracts

  • Lee, Young-Ju;Lee, Ka-Hwa;Ahn, Chang-Bum;Chun, Soon-Sil;Je, Jae-Young
    • Food Science and Biotechnology
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    • 제18권6호
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    • pp.1532-1536
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    • 2009
  • The objective of this study was to evaluate the antioxidant effects and acetylcholinesterase (AChE) inhibition activity of mulberry fruit extracts prepared by hot water (MFH) and 80% ethanol (MFE). Total polyphenolic contents of MFH and MFE were $195{\pm}3.4\;mg$ gallic acid equivalents/g MFH and $185{\pm}2.8\;mg$ gallic acid equivalents/g MFE. MFH and MFE significantly quenched 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide dose-dependently, and showed high chelating ability and reducing power in non-cellular systems. MFH and MFE also inhibited the formation of intracellular reactive oxygen species and lipid peroxidation, and elevated intracellular glutathione (GSH) levels in RAW264.7 cells. In addition, MFH and MFE also dose-dependently suppressed AChE activity.

천연물로부터 알코올 탈수소효소 저해제 검색 (Screening of Alcohol Dehydrogenase Inhibitors from Natural Products)

  • 이현주;이강만
    • 약학회지
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    • 제43권4호
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    • pp.481-486
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    • 1999
  • Excessive or long term ingestion of alcohol may cause hepatitis, cirrhosis, hepatic tumor and so on. Aldehyde and active form of free oxygen that are metabolites of alcohol in liver are the cause of liver cell damage. The main system of alcohol metabolism is composed of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and cytochrome P450. In connection with in vivo alcohol metabolism, more than one hundred natural products were screened for inhibition or activation of alcohol dehydrogenase. As a results, we found significant inhibition ($IC_50$) of ADH by methanolic extracts of Puerariae Radix ($61.2{\;}\mu\textrm{g}/ml$), Glycyrrhizae Radix ($105.0{\;}\mu\textrm{g}/ml$), Cinnamomi Ramulus ($7.0{\;}\mu\textrm{g}/ml$), Rhei Rhizoma ($36.7{\;}\mu\textrm{g}/ml$), Mori Cortex Radicis ($106.2{\;}\mu\textrm{g}/ml$), Chrysanthemi Flos ($112.2{\;}\mu\textrm{g}/ml$), Erycibes Caulis ($36.7{\;}\mu\textrm{g}/ml$), and Scutellariae Radix ($122.5{\;}\mu\textrm{g}/ml$)

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자궁경부암 세포주에서 활성산소종의 영향애 의한 Apoptosis를 통하여 세포성장을 억제하는 Cisplatin과 Berberine의 상승효과 (Synergistic Effect of Cisplatin and Berberine on Inhibition of Cell Growth and Induction of Apoptosis involving Oxidative Stress in HeLa Cells)

  • 조해중
    • 동의생리병리학회지
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    • 제21권4호
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    • pp.992-997
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    • 2007
  • Cisplatin is a chemotherapeutic drug which is widely used for cancer therapy including cervical cancer. The purpose of this study is to elucidate synergistic effect of Cisplatin and Berberine on the apoptosis of HeLa cells and to determine whether oxidants are formed as part of apoptotic process. Apoptotic death of HeLa cells by cisplatin and berberine was confirmed by chromatin condensation of HeLa cells and flow cytometric analysis of intracellular ROS(reactive oxygen species) production. In MTT assay, Cell viability was decreased and enhanced ROS generation in combination of cisplatin and berberine significantly, as compared with cisplatin only. Synergistic effect of Cisplatin and Berberine on the inhibition of cell growth by apoptosis was clearly observed and ROS may play an important role in apoptosis. This effect suggest the possibility lowering the concentration of chemotherapeutic drugs, which alleviate the side effect of drugs.

Methyl Linoleate Oxidation via Electron Transfer in Competition with $^1O_2$ Formation Photosensitized N-Acetyl-L-Tryptophan 3-Methyl Indole

  • Yoon, Min-Joong;Song, Moon-Young;Cho, Dae-Won
    • Bulletin of the Korean Chemical Society
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    • 제6권5호
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    • pp.291-295
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    • 1985
  • The efficiency of photosensitization of methyl linoleate (ML) oxidation by N-acetyl-L-trypophan(NAT) and 3-methyl indole(scatole) was markedly enhanced by increased concentration of ML in ethanol solution. The fluorescence intensities of sensitizers were observed to be quenched by ML, indicating that ML interacts with the indole excited singlet state. The inhibition of photosensitization by azide demonstrated a possible role of singlet oxygen in the photosensitization. The steady state kinetic treatment of azide inhibition of photosensitization was expected to show linear increase of reciprocal yield of ML oxidation product vs. reciprocal ML concentration at constant azide concentration, but the actual slope was nonlinear. This indicates another competing reaction involved in the photosensitization, As a possible competing reaction, electron transfer from ML to the excited sensitizer was proposed, since the measured fluorescence quenching rate constant closely resembled electron transfer rate constant determined from ML concentration dependence of oxidation product formation.

Astaxanthin Inhibits Autophagic Cell Death Induced by Environmental Hormones in Human Dermal Fibroblasts

  • Lim, Seong-Ryeong;Lee, Sei-Jung
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2020년도 정기학술대회 발표논문집
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    • pp.218-218
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    • 2020
  • Astaxanthin, a natural antioxidant carotenoid, has been thought to provide health benefits by decreasing the risk of oxidative stress?related diseases. In the present study, we investigated the effect of an astaxanthin during the autophagic cell death induced by bisphenol A (BPA) which is known major environmental pollutants. We found that astaxanthin significantly blocked the autophagic cell death via inhibition of intracellular Reactive Oxygen Species (ROS) in normal human dermal fibroblasts. Astaxanthin significantly inhibited the phosphorylation mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) responsible for the expression of LC3-II and Beclin-1 in BPA-treated normal human dermal fibroblasts. We suggest that astaxanthin blocks autophagic cell death induced by BPA via the inhibition of ROS-mediated signaling events in human dermal fibroblasts.

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식물세포 미토콘드리아막에서 일어나는 청색광 Photosensitization (Blue Light Photosensitization in Mitochondrial Membrane of Plant Cells)

  • 김경현;김종평;정진
    • 한국환경농학회지
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    • 제6권2호
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    • pp.94-100
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    • 1987
  • 미토콘드리아는 가시광선의 조사에 의해 그 고유한 생화학적 기능에 저해를 받게 되며 그것은 주로 파장 영역 $350{\sim}500nm$의 청색광이 유발하는 광역학적 작용(photodynamic action)의 결과라는 가정을 입증하는 자료를 수집하였다. 미토콘드리아막에 결합되어 있는 전자전달계효소들 중에서 NADH dehydrogenase, succinate dehydrogenase, 및 cytochrome c oxidase의 광저해(photoinhibition)를 조사하였던 바, 모든 효소들이 청색광에 의해 상대적으로 심한 활성상실을 보였다. NADH dehydrogenase의 FMN과 cytochrome c oxidase의 heme group은 산소가 관여하는 photosensitizer(photodynamic sensitizer)임에 반해, succinate dehydrogenase의 FAD는 sensitizer로서의 기능을 보이지 않는 대신 Fe-S center가 산소와 무관한 photosensitizer일 것이라고 해석되었다. heme group에 들어 있는 Fe도 역시 산소와 무관한 광화학반응에 어느 정도 기여하리라고 추정되는 결과도 얻었다. 미토콘드리아 전체로 볼 때 생리적 활성저해에 가장 크게 기여하는 가시광은 산소존재 조건하의 청색광이였고, 그 저해기작에는 active oxygens가 관여되어 있다는 것을 $O_2$의 분석을 통해 확인하였다. 한편 active oxygens의 생성은 미토콘드리아막의 과산화를 초래하였으며, 역시 청색광/$O_2$조건에서 그 정도가 가장 심하였다.

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U937을 이용한 활성산소 유도와 염증관련 아라키돈산 유리에 있어 은행잎 엑스의 억제 효과 (Effect of Inhibitions of Ginkgo biloba Extracts on Induction of Reactive Oxygen Species and Release of Inflammation Mediator Arachidonic Acid from U937)

  • 강상모
    • 한국식품과학회지
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    • 제32권5호
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    • pp.1198-1205
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    • 2000
  • 은행잎 엑스 3종류를 이용하여 활성산소와 염중관련 아라키돈산 유리의 억제능을 보았다. 은행잎 엑스, Ginkgolide A, Ginkgolide B의 3종류 모두 pyrogallol 자동산화에서는 항산화능을 발휘하지 못하였으나, DPPH법의 전자공여능에서는 환원력을 나타내었다. 10 ${\mu}M$ 과산화수소($IC_{50}=10\;{\mu}M$)로 U937의 지질과산화 유도 시 은행잎 엑스 3종류 모두 400 ${\mu}g/mL$이상에서는 보호하였으나, 은행잎 엑스가 가장 좋았다. 단백질 분해실험에서는 Ginkgolide A만이 효과가 좋아 50 ${\mu}g/mL$에서도 거의 억제하였다. TPA와 calcimycin을 U937에 첨가하여 염중 유도의 중요 물질인 아라키돈산 유리를 유도하였다. 이 아라키돈산 유리 유도 시 은행잎 엑스 3종류 모두 10 ${\mu}g/mL$에서도 뛰어난 억제능을 보였으며, 특히 Ginkgolide B는 유도 시에 비하여 11배 억제하였으며, 비유도시인 대조군보다도 약 4배의 억제능을 보였다. 따라서 은행잎 엑스가 항산화능에 의해 아라키돈산 유리를 억제하는 것이 아니라 아라키돈산 유리의 전 단계의 어느 부분을 강하게 억제하여 아라키돈산 유리가 저해되는 것으로 생각된다.

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Differential Inhibition of $MPP^+$- or 6-Hydroxydopamine-induced Cell Viability Loss in PC12 Cells by Trifluoperazine and W-7

  • Lee, Chung-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • 제9권4호
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    • pp.247-253
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    • 2005
  • The present study assessed the effect of calmodulin antagonists trifluoperazine and W-7 against the cytotoxicity of $MPP^+$ and 6-bydroxydoparnine (6-OHDA) in relation to the mitochondrial dysfunction and cell death in PC12 cells. Trifluoperazine (an inhibitor of the mitochondrial permeability transition and calmodulin antagonist) and W-7 (a specific calmodulin antagonist) significantly attenuated the $MPP^+-induced$ cell viability loss in PC12 cells with a maximum inhibition at $0.5{\sim}1{\mu}M$; beyond these concentrations the inhibitory effect declined. Both compounds at this concentration range did not cause cell death significantly. In contrast to $MPP^+$, the trifluoperazine and W-7 did not depress the cytotoxic effect of 6-OHDA. Addition of trifluoperazine and W-7 inhibited the cytosolic accumulation of cytochrome c and caspase-3 activation in PC12 cells treated with $MPP^+$ and attenuated the formation of reactive oxygen species and the depletion of GSH, whereas both compounds did not reduce the effect of 6-OHDA. The results show that trifluoperazine and W-7 may attenuate the cytotoxicity of $MPP^+$ by inhibition of the mitochondrial permeability transition and calmodulin. Meanwhile, the cytotoxic effect of 6-OHDA seems to be mediated by the actions, which are different from $MPP^+$.

Molecular mechanisms of luteolin-7-O-glucoside-induced growth inhibition on human liver cancer cells: G2/M cell cycle arrest and caspase-independent apoptotic signaling pathways

  • Hwang, Yu-Jin;Lee, Eun-Ju;Kim, Haeng-Ran;Hwang, Kyung-A
    • BMB Reports
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    • 제46권12호
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    • pp.611-616
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    • 2013
  • Luteolin-7-O-glucoside (LUT7G), a flavone subclass of flavonoids, has been found to increase anti-oxidant and anti-inflammatory activity, as well as cytotoxic effects. However, the mechanism of how LUT7G induces apoptosis and regulates cell cycles remains poorly understood. In this study, we examined the effects of LUT7G on the growth inhibition of tumors, cell cycle arrest, induction of ROS generation, and the involved signaling pathway in human hepatocarcinoma HepG2 cells. The proliferation of HepG2 cells was decreased by LUT7G in a dose-dependent manner. The growth inhibition was due primarily to the G2/M phase arrest and ROS generation. Moreover, the phosphorylation of JNK was increased by LUT7G. These results suggest that the anti-proliferative effect of LUT7G on HepG2 is associated with G2/M phase cell cycle arrest by JNK activation.

엽록체의 전자전달과 광음향 신호에 미치는 Simetryne의 영향 (Effect of Simetryne on Chloroplast-Mediated Electron Transport and Photoacoustic Signal)

  • 김현식
    • Journal of Plant Biology
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    • 제31권3호
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    • pp.205-215
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    • 1988
  • The effects of simetryne on light induced electron transport and phosphorylation in isolated spinach (Spinacia oleracea L.) chloroplasts were investigated in comparison with sencor and DCMU. Simetryne, like sencor and DCMU, completely, inhibited PSII electron transport and phosphoryltion with 10-6 M treatment but did not inhibit PSI electron transport. Interference with the electron transport pathway was evidenced by the greater sensitivity of oxygen evolution and uptake than phosphorylation. The following order of decreasing inhibitory effectiveness was exihibited; DCMU>simetryne>sencor. The photoacoustic technique was also used to monitor the relative photosynthetic activity in the leaves treated with the herbicides (simetryne, sencor or DCMU) in vivo and in vitro. Photoacoustic measurements on intact leaves provide quantitative information on two related aspects of the photosynthetic process, namely, photochemical energy storage and oxygen evolution. The relative photoacoustic signal of leaves treated with the herbicides showed low level in 21 Hz, but high level in 380 Hz and on isolated chloroplasts (both 21 Hz and 380 Hz) in comparison with that of the untreated leaves. These results suggest that some of photochemical energy is converted into the heat owing to the inhibition of electorn transport pathway by the herbicides.

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