• Title/Summary/Keyword: phase II enzyme

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Impact of Tobacco on Glutathione S Transferase Gene Loci of Indian Ethnics

  • Senthilkumar, K.P.;Thirumurugan, Ramasamy
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.5037-5042
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    • 2012
  • Background: Tobacco contains agents which generate various potent DNA adducts that can cause gene mutations. Production of DNA adducts may be neutralized by glutathione S transferase (GST) along with other phase I and phase II enzyme systems. The existence of null type of GST among the population increases the susceptibility to various disorders and diseases. The present study focuses on the impact of high tobacco usage and possible null type mutation in GST loci. Methods: Genotypes of GST were detected by multiplex polymerase chain reaction in unrelated 504 volunteers of high tobacco using natives of Gujarat. Allelic frequencies were calculated using Statistical Package for Social Studies-16 software. Hardy Weinberg Equilibrium (HWE) was calculated using Chi square test. Two sided Fisher's significance test was used to compare allelic frequencies of different populations. Results: The frequency of homozygous null genotype of GSTM1 and GSTT1 were 20% (95% CI 16.7-23.9) and 35.5% (95% CI 31.4-39.9) respectively. The GSTM1 and GSTT1 null allele frequency distribution in the Gujarat population was significantly deviating from HWE. GSTT1 null frequency of Gujaratians was significantly higher and different to all reported low tobacco using Indian ethnics, while GSTM1 was not differing significantly. Conclusion: Tobacco usage significantly influences the rate of mutation and frequency of GSTT1 and M1 null types among the habituates. The rate of mutation in GSTT1 loci was an undeviating response to the dose of tobacco usage among the population. This mutational impact of tobacco on GSTT1 postulates the possible gene - environment interaction and selection of null genotype among the subjects to prone them under susceptible status for various cancers and even worst to cure the population with GSTT1 dependent drugs.

GENETIC POLYMORPHISMS OF THE GLUTATHIONE S-TRANSFERASE AND CYP1A1 GENES IN KOREAN ORAL SQUAMOUS CELL CARCINOMA (한국인 구강 편평세포암에서 Glutathione S-transferase와 CYP1A1 유전자의 다형성)

  • Cha, In-Ho;Kwon, Jong-Jin;Park, Kwang-Kyun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.28 no.5
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    • pp.364-371
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    • 2002
  • Many chemical compopunds are converted into reactive electrophilic metabolites by the oxidative(Phase I) enzymes, which are mainly cytochrome P-450 enzyme(CYPs). Phase II conjugating enzymes, such as glutathione S-transferase(GST), usually act as inactivation of enzymes. Genetic polymorphisms have been found to be associated with increased susceptibility to cancer of the lung, bladder, breast and colorectal. Many of the polymorphic genes of carcinogen metabolism show considerably different type of cancer among different ethnic groups as well as individuals within the same group. The aim of this study is (1) to establish the frequencies of genetic polymorphisms of GSTM1 and CYP1A1 in Korean oral squamous cell carcinoma(SCC), (2) to associate oral SCC with the risk of these genetic polymorphisms. The genetic polymorphisms of the GSTM1 and the CYP1A1 genes among 50 Korean oral SCC were analyzed using polymerase chain reaction(PCR). The results suggest that the homozygote and the mutant type of CYP1A1 MspI polymorphisms may be associated with genetic susceptibility to oral SCC in Korean. A combination of the GSTM1 null type with the homozygote(m1/m1), and the mutant(m2/m2) type of CYP1A1 MspI polymorphisms showed a relatively high risk of oral SCC in Korean. In the smoking group, the GSTM1 wild genotype may be the high risk factor of oral SCC in Korean. These data coincide with the hypothesis which states that different susceptibility to cancer of genetic polymorphisms exist among different ethnic group and different types of human cancer.

Effect of Chronic Ethanol Consumption and Herbal Extracts Administration on the Antioxidant System and Ethanol Oxidation System in Rats (만성적인 에탄올 섭취와 천연물 투여가 흰쥐의 항산화계와 에탄올 산화계에 미치는 영향)

  • Kim, Mok-Kyung;Hyun, Sun-Hee;Choung, Se-Young
    • YAKHAK HOEJI
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    • v.50 no.4
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    • pp.254-262
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    • 2006
  • This study had been done for the investigation of the effect of Vitis vinifera extract(V), Schisandra chinensis extract (S), Taraxacum officinale extract (T), Gardenia jasminoides extract (G), Angelica acutiloba extract (A) and Paeonia japonica extract (P), and their mixtures on the antioxidant and ethanol oxidation system which was induced by Lieber-DeCarli ethanol liquid diet. Male Sprague-Dawley rats were randomly divided into eight groups: ethanol diet (ED), normal diet (ND), ED+V (100 mg/kg/day), ED+S, ED+T, ED+G, ED+A and ED+P (300 mg/kg/day). We studied the effect on alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) after herbal extracts administration for 6 weeks in rats induced by Lieber-DeCarli ethanol liquid diet. The differences in ADH and ALDH activity of the rats treated with herbal extracts and ED group were not significant. Phase I enzyme activity was found to be significantly higher in the ED+V than the ED group. Phase II enzymes (glutathione-S-transferase, phenol sulfatransferase) activities were found to be higher in the herbal extracts than the ED group. Herbal extracts not only reduced ethanol-induced elevation of level malondialdehyde but also protected against ethanol-induced decrease of reduced glutathione, gluthione reducatse, glutathione peroxidase, catalase and superoxide dismutase activities. Therefore, they can be utilized as a health functional food or new drug candidate for fatty liver and hepatotoxicity which was induced by chronic alcohol consumption.

The Mechanism of Nephrotoxicity Formation of Methotrexate in STZ-Induced Hyperglycemic Rats (Streptozotocin 유도 당뇨성 흰쥐에서 methotrexate의 신독성 생성기전에 관한 연구)

  • Kim Seok-Hwan;Kim Yeo-Jeong;Lee Joo-Yeon;Kang Hye-Ok;Lee Hang-Woo;Choi Jong-Won
    • Journal of Life Science
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    • v.16 no.2 s.75
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    • pp.259-265
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    • 2006
  • This study is investigated the effect on mechanism of nephrotoxicity formation of methotrexate(MTX) by hyperglycemic by streptozotocin(STZ). MTX was injected daily at two doses of 3, 6 mg/kg for 1 week in STZ-induced hyperglycemic rats. Activities of BUN, creatinine and LDH were significantly increased by treatment with MTX in STZ-induced diabetic group when compared to MTX treatment group in normal rats' Renal lipid peroxide content and activities of cytosolic enzyme were significantly increased in the treatment of MTX in diabetic group. The concentration of glutathione and glutathione biosynthesis enzymes were decreased by treatment with MTX in STZ-induced diabetic group. These results suggest that nephrotoxicity of MTX in STZ-induced hyperglycemic rat was caused by activation of renal metabolizing enzymes in cytosol and decrease of glutathione concentration.

Bleomycin Inhibits Proliferation via Schlafen-Mediated Cell Cycle Arrest in Mouse Alveolar Epithelial Cells

  • Jang, Soojin;Ryu, Se Min;Lee, Jooyeon;Lee, Hanbyeol;Hong, Seok-Ho;Ha, Kwon-Soo;Park, Won Sun;Han, Eun-Taek;Yang, Se-Ran
    • Tuberculosis and Respiratory Diseases
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    • v.82 no.2
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    • pp.133-142
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    • 2019
  • Background: Idiopathic pulmonary fibrosis involves irreversible alveolar destruction. Although alveolar epithelial type II cells are key functional participants within the lung parenchyma, how epithelial cells are affected upon bleomycin (BLM) exposure remains unknown. In this study, we determined whether BLM could induce cell cycle arrest via regulation of Schlafen (SLFN) family genes, a group of cell cycle regulators known to mediate growth-inhibitory responses and apoptosis in alveolar epithelial type II cells. Methods: Mouse AE II cell line MLE-12 were exposed to $1-10{\mu}g/mL$ BLM and $0.01-100{\mu}M$ baicalein (Bai), a G1/G2 cell cycle inhibitor, for 24 hours. Cell viability and levels of pro-inflammatory cytokines were analyzed by MTT and enzyme-linked immunosorbent assay, respectively. Apoptosis-related gene expression was evaluated by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Cellular morphology was determined after DAPI and Hoechst 33258 staining. To verify cell cycle arrest, propidium iodide (PI) staining was performed for MLE-12 after exposure to BLM. Results: BLM decreased the proliferation of MLE-12 cells. However, it significantly increased expression levels of interleukin 6, tumor necrosis factor ${\alpha}$, and transforming growth factor ${\beta}1$. Based on Hoechst 33258 staining, BLM induced condensation of nuclear and fragmentation. Based on DAPI and PI staining, BLM significantly increased the size of nuclei and induced G2/M phase cell cycle arrest. Results of qRT-PCR analysis revealed that BLM increased mRNA levels of BAX but decreased those of Bcl2. In addition, BLM/Bai increased mRNA levels of p53, p21, SLFN1, 2, 4 of Schlafen family. Conclusion: BLM exposure affects pulmonary epithelial type II cells, resulting in decreased proliferation possibly through apoptotic and cell cycle arrest associated signaling.

ACE Inhibitory Lignan Glycosides Isolated from Eucommia ulmoides Oliver (두충으로부터 분리한 Iignan glycoside 의 ACE 활성 억제)

  • Joo, Ok-Soo;Nam, Sang-Hae
    • Journal of Life Science
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    • v.19 no.6
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    • pp.698-704
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    • 2009
  • To evaluate a potential possibility of Eucommia ulmoides Oliver as a functional food, ACE (angiotensin converting enzyme) inhibitory activities of leaf, bark, stem and 4 compounds isolated from E. ulmoides were tested. The 4 compounds were isolated and purified by silica gel column chromatography, thin layer chromatography and reverse phase column chromatography. Compound I was pinoresinol-4,4'di-O-${\beta}$-D-glucoside (PG) and compound II was dehydrodiconiferyl alcohol 4,${\gamma}$'-di-O-${\beta}$-D-glucopyranoside (DAG) originating from Eucommial Cortex. The highest amount of PC was present at raw and roasted bark as 135.13 mg% and 163.67 mg%, and the highest amount of DAG was present at raw and roasted leaf as 117.93 mg% and 133.93 mg% respectively. In an ACE inhibition test, 10 mg/ml of roasted leaf, raw and roasted bark extracts of E. ulmoides Oliver were 77.49%, 75.72% and 75.36% respectively, and 10mg/ml of PC and DAG were shown to be 78.51 and 81.20% respectively. $IC_{50}$ values of PG and DAG were 0.6${\pm}$0.2 and 0.5${\pm}$0.2 mg/ml respectively.

Accelerated DNA Adduct Formation in the Lung of the Nrf2 Knockout Mouse Exposed to Diesel Exhaust

  • Aoki, Yasunobu;Sato, Hiromi;Nishimura, Noriko;Takahashi, Satoru;Itoh, Ken;Yamamoto, Masayuki
    • Proceedings of the Korea Environmental Mutagen Society Conference
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    • 2002.05a
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    • pp.36-42
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    • 2002
  • Diesel exhaust (DE) has been recognized as a noxious mutagen and/or carcinogen, because its components can form DNA adducts. Mechanisms governing the susceptibility to DE and the efficiency of such DNA adduct formation require clarification. The transcription factor Nrf2 is essential for inducible and/or constitutive expression of a group of detoxification and antioxidant enzymes, and we hypothesized that the nrf2 gene knockout mouse might serve as an excellent model system for analyzing DE toxicity. To address this hypothesis, lungs from nrf2(-/-) and nrf2(+/-) mice were examined for the production of xenobiotic-DNA adducts after exposure to DE (3 $mg/m^{3}$ suspended particulate matter) for 4 weeks. Whereas the relative adduct levels (RAL) were significantly increased in the lungs of both nrf2(+/-) and nrf2(-/-) mice upon exposure to DE, the increase of RAL in the lungs from nrf2(-/-) mice exposed to DE were approximately 2.3-fold higher than that of nrf2(+/-) mite exposed to DE. In contrail, cytochrome P4501Al mRNA levels in the nrf2(-/-)mouse lungs were similar to those in the nrf2(+/-) mouse lungs even after exposure to DE, suggesting that suppressed activity of phase II drug-metabolizing enzymes is important in giving ise to the increased level of DNA adducts in the Nrf2-null mutant mouse subjected to DE. Importantly, severe hyperplasia and accumulation of the oxidative DNA adduct 8-hydroxydeoxyguanosine were observed in the bronchial epidermis of nrf(-/-) mite following DE exposure. These results demonstrate the increased susceptibility of the nrf2 germ line mutant mouse to DE exposure and indicate the nrf2 gene knockout mouse nay represent a valuable model for the assessment of respiratory DE toxicity.

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Suppressive Effects of Defatted Green Tea Seed Ethanol Extract on Cancer Cell Proliferation in HepG2 Cells (HepG2 Cell에서 녹차씨박 에탄올 추출물의 암세포 증식 억제효과)

  • Noh, Kyung-Hee;Min, Kwan-Hee;Seo, Bo-Young;Kim, Hye-Ok;Kim, So-Hee;Song, Young-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.6
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    • pp.767-774
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    • 2011
  • Defatted green tea seed was extracted with 100% ethanol for 4 hr and then fractionated with petroleum ether, ethyl acetate and butanol. The ethanol and butanol extracts showed greater increases in antiproliferation potential against liver cancer cells than petroleum ether, ethyl acetate, $H_2O$, and hot water extracts did. Thus, this study was carried out to investigate the anti-proliferative actions of defatted green tea seed ethanol extract (DGTSE) in HepG2 cancer cells. The DGTSE contained catechins including EGC ($1039.1{\pm}15.2\;g/g$), tannic acid ($683.5{\pm}17.61\;{\mu}g/g$), EC ($62.4{\pm}5.00\;{\mu}g/g$), ECG ($24.4{\pm}7.81\;{\mu}g/g$), EGCG ($20.9{\pm}0.96\;{\mu}g/g$) and gallic acid ($2.4{\pm}0.68\;{\mu}g/g$), but caffeic acid was not detected when analyzed by HPLC. The anti-proliferation effect of DGTSE toward HepG2 cells was 83.13% when treated at $10\;{\mu}g$/mL, of DGTSE, offering an $IC_{50}$ of $6.58\;{\mu}g$/mL. DGTSE decreased CYP1A1 and CYP1A2 protein expressions in a dose-dependent manner. Quinone reductase and antioxidant response element (ARE)-luciferase activities were increased about 2.6 and 1.94-fold at a concentration of $20\;{\mu}g$/mL compared to a control group, respectively. Enhancement of phase II enzyme activity by DGTSE was shown to be mediated via interaction with ARE sequences in genes encoding the phase enzymes. DGTSE significantly (p<0.05) suppressed prostaglandin $E_2$ level, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) protein expressions, and NF${\kappa}$B translocation, but did not affected nitric oxide production. From the above results, it is concluded that DGTSE may ameliorate tumor and inflammatory reactions through the elevation of phase II enzyme activities and suppression of NF${\kappa}$B translocation and TNF-${\alpha}$ protein expressions, which support the cancer cell anti-proliferative effects of DGTSE in HepG2 cells.

Cancer Chemopreventive Effects of Korean Seaweed Extracts

  • Lee, Saet-Byoul;Lee, Joo-Young;Song, Dae-Geun;Pan, Cheol-Ho;Nho, Chu-Won;Kim, Min-Cheol;Lee, Eun-Ha;Jung, Sang-Hoon;Kim, Hyung-Seop;Kim, Yeong-Shik;Um, Byung-Hun
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.613-622
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    • 2008
  • Cancer chemopreventive effects can be exerted through the induction of phase II detoxification enzymes and the inhibition of inflammatory responses. In this study, the cancer chemopreventive effects and anti-inflammatory responses of 30 seaweed extracts were examined. The extracts of Dictyota coriacea and Cutleria cylindrica exhibited the high chemoprevention index, having 4.36 and 4.66, respectively. They also activated antioxidant response element at $100\;{\mu}g/mL$ by about 3-fold while did not activate xenobiotic response element. Seven seaweed extracts, Ishige okamurae, Desmarestia ligulata, Desmarestia viridis, Dictyopteris divaricata, D. coriacea, Sargassum horneri, and Sargassum yezoense, showed significant inhibition on nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production in a dose-dependant manner in $5-20\;{\mu}g/mL$. These seaweed extracts could be used as food materials for cancer chemoprevention. D. coriacea could contain potential chemopreventive agents not only that regulate genes via an ARE-dependent mechanism but also prevent the inflammation through inhibition of NO and $PGE_2$ production.

Cloning of Acetyl CoA Carboxylase (fabE) in Escherichia coli (대장균의 acetyl CoA carboxylase유전자의 클로닝)

  • Park, Wan;Song, Bang-Ho;Hong, Soon-Duk
    • Microbiology and Biotechnology Letters
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    • v.14 no.2
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    • pp.181-186
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    • 1986
  • A defective lambda transducing phase carrying acetyl CoA carboxylase gene (fabE) from Escherichia coli chromosome (72 min on the current linkage map) has been isolated. A restriction map of the chromosomal region from defective transducing phage was established by digestion with combination of the restriction enzymes. No cleavage site for the enzyme EcoRI was found in this region. Restriction fragments were cloned from defective transducing phage into high copy number plasmid vector pACYC184 to generate hybrid plasmids which were capable of complementation of fabE temperature sensitive mutation. We show here that the fabE gene is located on a 3.4 megadalton Bam HI-SalI fragment with a HindIII site, which lies within the 7.4 megadalton BglIIfragment, by complementation analysis.

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