• 제목/요약/키워드: phase II enzyme

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Cellulomonas sp.의 β-글루코시다아제 생성 (β-Glucosidase Formation In Cellulomonas sp.)

  • 최우영
    • 농업과학연구
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    • 제3권2호
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    • pp.225-234
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    • 1976
  • 섬유소 분해균 Cellulomonas sp. CS1-1의 각종 탄소원에서의 ${\beta}$-글루코시다아제 생성을 살피기 위하여 Quickfit FVIL 발효장치를 이용하고, 뉴트리엔트 이스트브로스, 카르복시멜틸셀룰로오스, 아비셀, 셀로비오스 등을 탄소원으로 한 배지에 뱃치로 배양하여 그 배양적 특성과 세포내 또는 세포외 ${\beta}$-글루코시다아제의 분포를 검토한 결과 : i)${\beta}$-글루코시다아제는 공시한 모든 배양 조건하에서 생성되었고 세포내 효소로서 배양여액에서는 검출되지 않았다. ii) 뉴트리엔트 이스트브로스와 카르복시메틸 셀룰로오스를 탄소원으로 할 때 보다 셀로비오스 및 아비셀을 탄소원으로 하는 경우 효소의 비활성도가 높았다. iii) 공시한 모든 기질에서 공히 균의 대수기(對數期)에 극대치의 비활성도를 나타내었다.

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Histone Deacetylase in Carcinogenesis and Its Inhibitors as Anti-cancer Agents

  • Kim, Dong-Hoon;Kim, Min-Jung;Kwon, Ho-Jeong
    • BMB Reports
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    • 제36권1호
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    • pp.110-119
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    • 2003
  • The acetylation state of histone is reversibly regulated by histone acetyltransferase (HAT) and deacetylase (HDAC). An imbalance of this reaction leads to an aberrant behavior of the cells in morphology, cell cycle, differentiation, and carcinogenesis. Recently, these key enzymes in the gene expression were cloned. They revealed a broad use of this modification, not only in histone, but also other proteins that involved transcription, nuclear transport, and cytoskeleton. These results suggest that HAT/HDAC takes charge of multiple-functions in the cell, not just the gene expression. HDAC is especially known to play an important role in carcinogenesis. The enzyme has been considered a target molecule for cancer therapy. The inhibition of HDAC activity by a specific inhibitor induces growth arrest, differentiation, and apoptosis of transformed or several cancer cells. Some of these inhibitors are in a clinical trial at phase I or phase II. The discovery and development of specific HDAC inhibitors are helpful for cancer therapy, and decipher the molecular mode of action for HDAC.

Naturally-Occurring Glucosinolates, Glucoraphanin and Glucoerucin, are Antagonists to Aryl Hydrocarbon Receptor as Their Chemopreventive Potency

  • Razis, Ahmad Faizal Abdull;Noor, Noramaliza Mohd
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권14호
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    • pp.5801-5805
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    • 2015
  • As a cytosolic transcription factor, the aryl hydrocarbon (Ah) receptor is involved in several pathophysiological events leading to immunosuppression and cancer; hence antagonists of the Ah receptor may possess chemoprevention properties. It is known to modulate carcinogen-metabolising enzymes, for instance the CYP1 family of cytochromes P450 and quinone reductase, both important in the biotransformation of many chemical carcinogens via regulating phase I and phase II enzyme systems. Utilising chemically-activated luciferase expression (CALUX) assay it was revealed that intact glucosinolates, glucoraphanin and glucoerucin, isolated from Brassica oleracea L. var. acephala sabellica and Eruca sativa ripe seeds, respectively, are such antagonists. Both glucosinolates were poor ligands for the Ah receptor; however, they effectively antagonised activation of the receptor by the avid ligand benzo[a]pyrene. Indeed, intact glucosinolate glucoraphanin was a more potent antagonist to the receptor than glucoerucin. It can be concluded that both glucosinolates effectively act as antagonists for the Ah receptor, and this may contribute to their established chemoprevention potency.

Potential Induction of Quinone Reductase Activity of Natural Products in Cultured Murine Hepa1c1c7 Cells

  • Heo, Yeon-Hoi;Lee, Sang-Kook
    • Natural Product Sciences
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    • 제7권2호
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    • pp.38-44
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    • 2001
  • NAD(P)H:quinone reductase (QR), known as DT-diaphorase, is a kind of detoxifying phase II metabolic enzyme catalyzing hydroquinone formation by two electron reduction pathway from quinone type compounds, and thus facilitating excretion of quinoids from human body. With the usefulness of QR induction activity assay system for the modulation of toxicants, in the course of searching for cancer chemopreventive agents from natural products, the methanolic extracts of approximately two hundreds of oriental medicines were primarily evaluated using the induction potential of quinone reductase (QR) activity in cultured murine Hepa1c1c7 cells. As a result, several extracts including Hordeum vulgare, Momordica cochinchinensis, Strychnos ignatii, Houttuynia cordata, and Polygala japonica were found to significantly induce QR activity. In addition, the methylene chloride fraction of H. vulgare, one major dietary food source, showed potent induction of QR activity $(CD=6.4{\mu}g/ml)$. Further study for isolation of active principles from these lead extracts is warranted for the discovery of novel cancer chemopreventive agents.

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괴화약침액이 간세포의 Quinone redutase 와 Glutathione S-transferase 활성에 미치는 영향 (Effect of Sophorae Flos Aqua-acupuncture Solution on the Quinone Reductase and Glutathione S-transferase Activities of Hepa 1c1c7 Cells)

  • 이기택;임종국
    • Korean Journal of Acupuncture
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    • 제20권1호
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    • pp.39-43
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    • 2003
  • 괴화약침액이 간세포의 quinone reductase, glutathione S-transferase 와 환원형 glutathione의 활성에 미치는 영향을 살펴 본 결과 괴화약침액은 암예방 효소인 Phase II enzyme을 유의성 있게 증가 시켰다. 따라서 괴화약침액은 암예방에 효과가 있는 것으로 사료된다.

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Ultrastructural localization of 28 kDa glutathione S-transferase in adult Clonorchis sinensis

  • Hong, Sung-Jong;Yu, Jae-Ran;Kang, Shin-Yong
    • Parasites, Hosts and Diseases
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    • 제40권4호
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    • pp.173-176
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    • 2002
  • Glutathione S-transferase (28GST) with molecular mass of 28 kDa is an anti-oxidant enzyme abundant in Clonorchis sinensis. In adult C. sinensis, 28GST was localized in tegumental syncytium, cytons, parenchyma, and sperm tails examined by immunoelectron microscopy. C. sinensis 28GST was earlier found to neutralize bio-reactive compounds and to be rich in eggs. Accordingly. it is suggested that 28GST plays important roles in phase II defense system and physiological roles in worm fecundity of C. sinensis.

Induction of Quinone Reductase by Obtusafuran from Dalbergiae Lignum

  • Yin, Hu-Quan;Oh, Seon-Hee;Kim, Youn-Chul;Sohn, Dong-Hwan;Lee, Byung-Hoon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.161.1-161.1
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    • 2003
  • NAD(P)H:quinone oxidoreductase (quinone reductase: QR: EC1.6.99.2), a cytosolic FAD-containing flavoprotein, form one of the important component of the phase II drug-metabolizing enzyme systems. It is found in all mammalian species tested and is expressed in many organs including the liver. QR catalyses two-electron reduction of qui nones to hydroquinones thereby suppresses the formation of superoxide anion radical. (omitted)

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Role of PI3-kinase and MAP Kinases in the ARE-mediated Glutathione S-Transferase Induction by Phytochemicals: Comparison with the Oxidative Stress Caused by Decreased Glutathione

  • Kim, Sang-Geon;Kang, Keon-Wook
    • Toxicological Research
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    • 제17권
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    • pp.251-256
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    • 2001
  • The expression of phase II detoxifying enzymes is affected by a variety of compounds and the induction of the enzymes plays an essential role in chemoprevention. A variety of phytochemicals such as sulfur-containing chemoprotective agents (SCC) may trigger cellular signals and activate phase II gene expression through ARE activation. see induces glutathione S-transferases. Studies were conducted to investigate the role of mitogen-activated protein (MAP) kinase and phosphatidylinositol 3-kinase (PI3-kinase) in the induction of GST (e.g. rGSTA2) by sec. We also studied the MAP kinase pathway responsible for the GST expression by see and compared that with the pathway activated by oxidative stress as a result of sulfur amino acids deprivation (SAAD). see inhibited phosphorylation of ERK1/2 although the effect of see on JNK and p38 MAP kinase was minimal. Wortmannin and LY294002. PI3-kinase inhibitors. abolished the increases in rGSTA2 mRNA and protein levels by SCC. Deprivation of cystine and methionine caused oxidative stress in H4IIE cells. as evidenced by a decrease in the reduced glutathione and an increase in prooxidant production. Electrophoretic mobility shift assay revealed that the ARE complex consisting of Nrf-1/2 and Maf proteins was activated 12~48 h. The rGSTA2 mRNA and protein levels were increased by SAAD. Activation of ARE and induction of rGSTA2 were both completely inhibited by PI3-kinase inhibitors. Inhibition of p38 MAP kinase by SB203580 prevented the ARE-mediated rGSTA2 induction. The results of this study showed that PI3-kinase might play an essential role in the ARE-mediated rGSTA2 induction by see or SAAD and that the dual MAP kinase pathways were responsible for the enzyme induction.

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Fermented Prunus mume with Probiotics Inhibits 7,12-Dimethylbenz[a]anthracene and 12-O-Tetradecanoyl phorbol-13-acetate Induced Skin Carcinogenesis through Alleviation of Oxidative Stress

  • Lee, Jin-A;Ko, Jae-Hyung;Jung, Bock-Gie;Kim, Tae-Hoon;Hong, Ji-In;Park, Young-Seok;Lee, Bong-Joo
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권5호
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    • pp.2973-2978
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    • 2013
  • Maesil (Prunus mume Siebold & Zucc.), a member of the genus Rosaceae, has been reported to have antioxidative effects, as well as anticancer influence in many cancer lines. Thus, this present study was designed to investigate the inhibitory effect of fermented Maesil with probiotics against 7,12-dimethylbenz[a]anthracene (DMBA), 12-O-tetradecanoyl phorbol 13-acetate (TPA)-induced mouse skin carcinogenesis via its antioxidative potential. Mice were fed a diet containing fermented Maesil, containing either 1% (1% FM fed group) or 2% (2% FM fed group) along with probiotics following DMBA and TPA exposure. Continuous ingestion of the experimental feed markedly inhibited skin carcinogenesis, as evidenced by a marked decrease in papilloma numbers and epidermal hyperplasia as well as cellular proliferation and the percentage of proliferating-cell nuclear antigen positive cells. Also, the FM fed group showed an increase of total antioxidant capacity as well as an increased level of phase II detoxifying enzymes such as superoxide dismutase, concurrent with a decreased lipid peroxidation activity level. Taken together, these results suggest that fermented Maesil has the ability to suppress the development of DMBA-TPA induced skin carcinogenesis, via the reduction of lipid peroxidation, enhancing total antioxidant capacity and phase II detoxifying enzyme.