• Title/Summary/Keyword: Enzyme inhibition

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Characterization of Lipoxygenase in AOT/Isooctane Reversed Micelles (AOT/isooctane 역미셀계내에서의 lipoxygenase 반응 특성)

  • Chang, Pahn-Shick;Lee, Kwang-In
    • Korean Journal of Food Science and Technology
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    • v.34 no.2
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    • pp.157-163
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    • 2002
  • An investigation was carried out to study the characteristics of lipoxygenase in dioctyl sulfosuccinate (aerosol-OT, AOT)/isooctane revered micelles of microaqueous system containing infinitesimal water. ${\alpha}-Linoleic$ acid as a substrate could be analyzed by the colorimetric methodology using 5%(w/v) cupric acetate-pyridine solution and the activity of lipoxygenase was able to be assayed by the degree of ${\alpha}-linoleic$ acid consumption per minute. Optimal pH, temperature, and R-value ([water]/[AOT]) were determined as the value of 5.0, $25^{\circ}C$, and 10.0, respectively. Kinetic analysis of the enzyme reaction under the optimal conditions showed that the values of $K_m$ and $V_{max}$ were 0.31 mM of ${\alpha}-linoleic$ acid and $384.16{\mu}mol$ of ${\alpha}-linoleic$ acid decomposed/min, respectively. The results indicate the reaction to be lipoxygenase-catalyzed oxidation of ${\alpha}-linoleic$ acid in AOT/isooctane reversed micellar system. The inhibitory effect of natural antioxidants on lipoxygenase showed little inhibitory effect of L-ascrobic acid while ${\alpha}-tocopherol$ showed 72% of inhibitory effect.

A Novel Pyruvate Kinase M2 Activator Compound that Suppresses Lung Cancer Cell Viability under Hypoxia

  • Kim, Dong Joon;Park, Young Soo;Kim, Nam Doo;Min, Sang Hyun;You, Yeon-Mi;Jung, Yuri;Koo, Han;Noh, Hanmi;Kim, Jung-Ae;Park, Kyung Chan;Yeom, Young Il
    • Molecules and Cells
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    • v.38 no.4
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    • pp.373-379
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    • 2015
  • Pyruvate kinase M2 isoform (PKM2), a rate-limiting enzyme in the final step of glycolysis, is known to be associated with the metabolic rewiring of cancer cells, and considered an important cancer therapeutic target. Herein, we report a novel PKM2 activator, PA-12, which was identified via the molecular docking-based virtual screening. We demonstrate that PA-12 stimulates the pyruvate kinase activity of recombinant PKM2 in vitro, with a half-maximal activity concentration of $4.92{\mu}M$, and effectively suppresses both anchorage-dependent and -independent growth of lung cancer cells in non-essential amino acid-depleted medium. In addition, PA-12 blocked the nuclear translocalization of PKM2 in lung cancer cells, resulting in the inhibition of hypoxia response element (HRE)-mediated reporter activity as well as hypoxia-inducible factor 1 (HIF-1) target gene expression, eventually leading to the suppression of cell viability under hypoxia. We also verified that the effects of PA-12 were dependent on PKM2 expression in cancer cells, demonstrating the specificity of PA-12 for PKM2 protein. Taken together, our data suggest that PA-12 is a novel and potent PKM2 activator that has therapeutic implications for lung cancer.

Elevation of anti-oxidative activity and inhibitory activities against tyrosinase, elastase, collagenase and hyaluronidase of Oplismenus undulatifolius by elicitor treatment (Elicitor 처리한 주름조개풀(Oplismenus undulatifolius)의 항산화, tyrosinase, elastase, collagenase 및 hyaluronidase 억제 활성 증대)

  • Lee, Eun-Ho;Cho, Young-Je
    • Journal of Applied Biological Chemistry
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    • v.63 no.3
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    • pp.221-227
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    • 2020
  • This study was designed to assess the change of the antioxidative and biological enzyme activities [tyrosinase, elastase, collagenase, and hyaluronidase (HAase)] of extracts from elicitor-treated Oplismenus undulatifolius. Elicitor-treated O. undulatifolius showed higher total phenolic content than the non-treated extract. As a result of comparing the anti-oxidant activity of elicitor-treated O. undulatifolius extract and non-treated extract, the elicitor-treated group showed high activity. Elicitor-treated O. undulatifolius showed higher elastase and collagenase inhibitory activities as anti-wrinkle effect, tyrosinase inhibitory activity as whitening effect, and anti-inflammation effect to induced as HAase inhibition than the non-treated extract. Therefore, elicitor-treatment during O. undulatifolius cultivation in outdoors will elevate total phenolics content in the plant and elevate of various bioactivities, which will yield high quality for industrialization.

Anti-Oxidative and Anti-Inflammatory Effects of Malus huphensis, Ophiorrhiza cantonensis, and Psychotria rubra Ethanol Extracts (Malus huphensis, Ophiorrhiza cantonensis, Psychotria rubra 에탄올 추출물의 항산화 및 항염증 활성)

  • Jin, Kyong-Suk;Kwon, Hyun Ju;Kim, Byung Woo
    • Microbiology and Biotechnology Letters
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    • v.42 no.3
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    • pp.275-284
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    • 2014
  • This study was orchestrated with the purpose of uncovering new nutraceutical resources possessing biological activities in the plant kingdom. To fulfill our objective, we analyzed several Chinese plants and selected three possessing powerful anti-oxidative activities. The anti-oxidative and anti-inflammatory effects these three Chinese plants, Malus hupehensis, Ophiorrhiza cantonensis, and Psychotria rubra ethanol extracts were then evaluated. First of all, they possessed potent scavenging activity against 1,1-diphenyl-2-picryl hydrazyl, similar with that of ascorbic acid, used as a positive control. Moreover, they inhibited lipopolysaccharide (LPS)- and hydrogen peroxide-induced reactive oxygen species, in a dose-dependent manner, in RAW 264.7 cells. Also, they induced the expression of an anti-oxidative enzyme, heme oxygenase 1, and its upstream transcription factor, nuclear factor-E2-related factor 2. Furthermore, they suppressed LPS-induced nitric oxide (NO) formation, without cytotoxicity. The inhibition of NO formation was the result of the down regulation of inducible NO synthase (iNOS). The suppression of NO and iNOS by the three extracts might be the result of modulation by the upstream transcription factors, nuclear factor ${\kappa}B$ and activator protein-1. Taken together, these results indicate that these three Chinese plants possess potent anti-oxidative and anti-inflammatory activities. Therefore, they might be utilized as promising materials in the field of nutraceuticals.

Molecular Characterization of a Novel 1,3-α-3,6-Anhydro-L-Galactosidase, Ahg943, with Cold- and High-Salt-Tolerance from Gayadomonas joobiniege G7

  • Seo, Ju Won;Tsevelkhorloo, Maral;Lee, Chang-Ro;Kim, Sang Hoon;Kang, Dae-Kyung;Asghar, Sajida;Hong, Soon-Kwang
    • Journal of Microbiology and Biotechnology
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    • v.30 no.11
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    • pp.1659-1669
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    • 2020
  • 1,3-α-3,6-anhydro-L-galactosidase (α-neoagarooligosaccharide hydrolase) catalyzes the last step of agar degradation by hydrolyzing neoagarobiose into monomers, D-galactose, and 3,6-anhydro-L-galactose, which is important for the bioindustrial application of algal biomass. Ahg943, from the agarolytic marine bacterium Gayadomonas joobiniege G7, is composed of 423 amino acids (47.96 kDa), including a 22-amino acid signal peptide. It was found to have 67% identity with the α-neoagarooligosaccharide hydrolase ZgAhgA, from Zobellia galactanivorans, but low identity (< 40%) with the other α-neoagarooligosaccharide hydrolases reported. The recombinant Ahg943 (rAhg943, 47.89 kDa), purified from Escherichia coli, was estimated to be a monomer upon gel filtration chromatography, making it quite distinct from other α-neoagarooligosaccharide hydrolases. The rAhg943 hydrolyzed neoagarobiose, neoagarotetraose, and neoagarohexaose into D-galactose, neoagarotriose, and neoagaropentaose, respectively, with a common product, 3,6-anhydro-L-galactose, indicating that it is an exo-acting α-neoagarooligosaccharide hydrolase that releases 3,6-anhydro-L-galactose by hydrolyzing α-1,3 glycosidic bonds from the nonreducing ends of neoagarooligosaccharides. The optimum pH and temperature of Ahg943 activity were 6.0 and 20℃, respectively. In particular, rAhg943 could maintain enzyme activity at 10℃ (71% of the maximum). Complete inhibition of rAhg943 activity by 0.5 mM EDTA was restored and even, remarkably, enhanced by Ca2+ ions. rAhg943 activity was at maximum at 0.5 M NaCl and maintained above 73% of the maximum at 3M NaCl. Km and Vmax of rAhg943 toward neoagarobiose were 9.7 mg/ml and 250 μM/min (3 U/mg), respectively. Therefore, Ahg943 is a unique α-neoagarooligosaccharide hydrolase that has cold- and high-salt-adapted features, and possibly exists as a monomer.

Physiological Function and Development of Beverage from Grifola frondosa (잎새버섯 추출물의 생리 기능 및 음료 제조)

  • Lee, Jae-Sung;Lee, Jong-Suk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.10
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    • pp.1241-1247
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    • 2007
  • Contents of polyphenol compounds and the physiological activity of extracts from Grifola frondosa by water and methanol extraction were investigated to determine their functional effects. A functional beverage was developed using the extracts. The yield and phenolic compounds content of the water extracts were highest (49.2% and 327 mg/100 g, respectively), while for the methanol extraction method they were 28.7% and 130 mg/100 g, respectively. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity was 76.3% for the water extract and 65.4% for methanol extract, whereas the superoxide dismutase (SOD)-like activity was low ($26.3{\sim}36.8%\;at\;1,000{\mu}g/mL$ concentration) Angiotensin converting enzyme (ACE) inhibitory effect of water extract (75.1%) was higher compared to the methanol extracts (41.2%). Tyrosinase inhibition activity was 42.5% for the water extracts and 31.8% for the methanol extracts at $1,000{\mu}g/mL$ concentration. The most acceptable formulation for G. frondosa beverage developed was 0.5% G. frondosa water extract, 8.0% oligosaccharide, 2.0% green tea extract, 2.0% jujube extract, 1.0% Solomon's seal extract, 0.01% vitamin C, and 2.0% apple extract. The final product had 9.8 Brix and color values of L, 35.2+1.1; a, 3.2+0.2; b, 13.6+0.3.

Antioxidant and Antihypertensive Activities of Styela plicata according to Harvesting Time and Size (채취시기와 크기에 따른 주름 미더덕의 항산화 및 항고혈압 활성)

  • Park, Ji-Won;You, Dong-Hyun;Bae, Myung-Suk;Kim, Jung-Mi;Lee, Jong-Hwa;Kim, Suk-Ju;Jeon, Yuo-Jin;Park, Eun-Ju;Lee, Seung-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.350-356
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    • 2011
  • Styela plicata of large (9.82~11.66 g) and small (0.93~2.21 g) sizes harvested at different times was extracted with 4 different solvents (methanol, ethanol, acetone, and water). DPPH radical scavenging and reducing power was the highest in acetone extracts of small ones (38.98% and 1.724, respectively) harvested in November. The lowest radical scavenging activity was found in water extracts of large ones (12.03% and 0.114) in December. On the other hand, large ones harvested in September showed significantly higher inhibition rate of DNA damage (water, 56.54%; methanol, 55.83%; ethanol, 48.63%) than others. Overall, the water extraction of S. plicata tended to show a higher antigenotoxic effect. In addition, water extracts of large S. plicata from November showed the highest angiotensin converting enzyme (ACE) inhibitory activity (64.38%), while that of small ones from December exhibited the lowest (51.33%). Overall the results indicate that antioxidant and antihypertensive activities S. plicata are variable depending on harvesting time, size, and extraction solvent.

Antioxidant and Antimicrobial Activities of Green Tea at Different Harvest Time (채취 시기가 다른 녹차의 생리활성 연구)

  • Kim, Bum-Keun;Park, Chan-Eun;Park, Kee-Jai;Lim, Jeong-Ho;Jeong, Jin-Woong;Jeong, Seung-Won;Cho, Chang-Won
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.4
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    • pp.570-578
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    • 2009
  • The present study was conducted to investigate the antioxidant and antimicrobial activities of green tea at different harvest time. The leaves were collected in late March(Ilro), early April(Okro and Ujeon), late April(Sejak), and early May(Eoksu and Hanra). The total polyphenol content of Sejak was highest (28.87mg TAE/g). Electron donating abilities toward $\alpha$,$\alpha$-diphenyl-$\beta$-picyryl hydrazyl (DPPH) radical were approximately 80%. SOD-like activities were above 30%, where ujeon showed the highest activity ($38.95{\pm}0.96%$). The nitrite scavenging ability was pH-dependent and shown to be highest at pH 1.2, and lowest at pH 6.0. The inhibitory effects against the angiotensin I converting enzyme were over 85%, except for Okro ($58.22{\pm}4.66%$) and Hanra ($77.96{\pm}3.83%$). The tyrosinase inhibition rate increased with harvest time. Okro showed the highest caffeine content ($3.86{\pm}0.32%$) and had the highest antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium. The combined results of this work revealed that the antioxidant and antimicrobial activities of green tea were independent of harvest time.

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An Experimental Study on Apoptosis of Cultivated Wild Ginseng Distilled Herbal Acupuncture by controlled pH and Electrolyte (pH 및 전해질 조절 산양산삼(山養山蔘) 증류약침(蒸溜藥鍼)의 Apoptosis에 관(關)한 실험적(實驗的) 연구(硏究))

  • Chu, Ching sheng;Lee, Sun-gu;Kwon, Ki-rok
    • Journal of Acupuncture Research
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    • v.21 no.6
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    • pp.1-17
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    • 2004
  • Objective : To compare and examine how adjustment of pH and electrolyte can affect the efficacy of cultivated wild ginseng distilled herbal acupuncture, we've administered pure cultivated wild ginseng distilled herbal acupuncture and pH and electrolyte adjusted cultivated wild ginseng distilled herbal acupuncture on A549 human lung cancer lines. Then mRNA and proteins which take parts in apoptosis were examined. Methods : Pure cultivated wild ginseng distilled herbal acupuncture treated group was set as the control group and pH and electrolyte adjusted cultivated wild ginseng distilled herbal acupuncture groups were administered on A549 human lung cancer lines. Cell toxicity was carefully examined and from the analysis of DNA fragmentation, RT-PCR, and Western blot, manifestation of mRNA and proteins which are associated with apoptosis were inspected. Results : The following results were obtained on apoptosis of A549 human lung cancer lines after administering pH and electrolyte adjusted cultivated wild ginseng distilled herbal acupuncture. 1. Measuring cell toxicity of lung cancer cells, higher cell toxicity was detected at pH and electrolyte adjusted groups and the results were concentration dependent. 2. Through DNA fragmentation, we were able to confirm cell destruction in all groups. 3. Experiment groups treated with cultivated wild ginseng distilled herbal acupuncture showed inhibition of Bcl-2 and COX-2 at mRNA and Protein level, whileas increase of Bax was shown. 4. Manifestation of p21, p53, Cyclin E, and Cyclin D1 were confirmed in all groups. 5. Extrication of Cytochrome C was detected at all groups, as well as increased activity of the enzyme caspase-3 and caspase-9, and PARP fragmentation were confirmed. Conclusions : From the above results, we can carefully deduce cell destruction of A549 human lung cancer lines were induced by Apoptosis. At the same concentration level, cell destruction efficacy was better with adjusted pH and electrolyte. Cultivated wild ginseng distilled herbal acupuncture also showed decrease of Bcl-2 and COX-2, as well as increase of Bax. Since cultivated wild ginseng distilled herbal acupuncture increases manifestation of p21, p53, Cyclin E, and Cyclin D1, it affects cellular cycle and through these phenomena, we can consider extrication of Cytochrome C, increase of caspase, and PARP fragmentation are the results.

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Vitamin D Inhibits Expression and Activity of Matrix Metalloproteinase in Human Lung Fibroblasts (HFL-1) Cells

  • Kim, Seo Hwa;Baek, Moon Seong;Yoon, Dong Sik;Park, Jong Seol;Yoon, Byoung Wook;Oh, Byoung Su;Park, Jinkyeong;Kim, Hui Jung
    • Tuberculosis and Respiratory Diseases
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    • v.77 no.2
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    • pp.73-80
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    • 2014
  • Background: Low levels of serum vitamin D is associated with several lung diseases. The production and activation of matrix metalloproteinases (MMPs) may play an important role in the pathogenesis of emphysema. The aim of the current study therefore is to investigate if vitamin D modulates the expression and activation of MMP-2 and MMP-9 in human lung fibroblasts (HFL-1) cells. Methods: HFL-1 cells were cast into three-dimensional collagen gels and stimulated with or without interleukin-$1{\beta}$ (IL-$1{\beta}$) in the presence or absence of 100 nM 25-hydroxyvitamin D (25(OH)D) or 1,25-dihydroxyvitamin D ($1,25(OH)_2D$) for 48 hours. Trypsin was then added into the culture medium in order to activate MMPs. To investigate the activity of MMP-2 and MMP-9, gelatin zymography was performed. The expression of the tissue inhibitor of metalloproteinase (TIMP-1, TIMP-2) was measured by enzyme-linked immunosorbent assay. Expression of MMP-9 mRNA and TIMP-1, TIMP-2 mRNA was quantified by real time reverse transcription polymerase chain reaction. Results: IL-$1{\beta}$ significantly stimulated MMP-9 production and mRNA expression. Trypsin converted latent MMP-2 and MMP-9 into their active forms of MMP-2 (66 kDa) and MMP-9 (82 kDa) within 24 hours. This conversion was significantly inhibited by 25(OH)D (100 nM) and $1,25(OH)_2D$ (100 nM). The expression of MMP-9 mRNA was also significantly inhibited by 25(OH)D and $1,25(OH)_2D$. Conclusion: Vitamin D, 25(OH)D, and $1,25(OH)_2D$ play a role in regulating human lung fibroblast functions in wound repair and tissue remodeling through not only inhibiting IL-$1{\beta}$ stimulated MMP-9 production and conversion to its active form but also inhibiting IL-$1{\beta}$ inhibition on TIMP-1 and TIMP-2 production.