• Title/Summary/Keyword: phase II enzyme

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

  • Choi, Woo-Young
    • Korean Journal of Agricultural Science
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    • v.3 no.2
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    • pp.225-234
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    • 1976
  • To elucidate ${\beta}$-glucosidase formation on various carbon scurces by cellulolytic bact-eia, Cellulomonas sp. CS1-1, the strain was grown on Nutrient Yeast Broth, carboxymethyl cellulose, avicel and cellobiose using a Ouickfit FVIL fermentor operated in batch, and the growth characteristics on those substrates and ${\beta}$-glucosidase distribution of extra and intracellular enzyme components were studied. The results were: 1) ${\beta}$-glucosidase was always intracellular, and was formed under all growth conditions tested, ii) but levels of relative activities were higher when the culture was grown on cellobiose and on avicel, iii) the relative activities were always maximum during the growth phase of the organism irrespective of the substrate used.

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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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    • v.7 no.2
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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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Effect of Sophorae Flos Aqua-acupuncture Solution on the Quinone Reductase and Glutathione S-transferase Activities of Hepa 1c1c7 Cells (괴화약침액이 간세포의 Quinone redutase 와 Glutathione S-transferase 활성에 미치는 영향)

  • Lee Ki-Taek;Lim Jong-Kook
    • Korean Journal of Acupuncture
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    • v.20 no.1
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    • pp.39-43
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    • 2003
  • Sophorae Flos aqua-acupuncture solution(SFAS) was prepared and tested for the induction of quinone reductase and glutathione S-transferase activities and glutathione. SFAS significantly induced QR activity at the concentrations of $0.5{\times},\;1{\times}\;and\;3{\times}$ in cell culture. However, GST activity in murine Hepa 1c1c7 cells was slightly increased with SFAS. SFAS increased GSH levels.

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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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    • v.40 no.4
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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
    • Proceedings of the PSK Conference
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    • 2003.04a
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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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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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    • v.36 no.1
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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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    • v.16 no.14
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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.

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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    • v.17
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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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    • v.14 no.5
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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.