• Title/Summary/Keyword: inhibition of metabolism

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Enhancement of L-Lactic Acid Production in Lactobacillus casei from Jerusalem Artichoke Tubers by Kinetic Optimization and Citrate Metabolism

  • Ge, Xiang-Yang;Qian, He;Zhang, Wei-Guo
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.101-109
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    • 2010
  • Efficient L-lactic acid production from Jerusalem artichoke tubers, by Lactobacillus casei G-02, using simultaneous saccharification and fermentation (SSF) in a fed-batch culture, is demonstrated. A kinetic analysis of the SSF revealed that the inulinase activity was subjected to product inhibition, whereas the fermentation activity of G-02 was subjected to substrate inhibition. It was also found that the intracellular NADH oxidase (NOX) activity was enhanced by the citrate metabolism, which dramatically increased the carbon flux of the Embden-Meyerhof-Parnas (EMP) pathway, along with the production of ATP. As a result, when the SSF was carried out at $40^{\circ}C$ after an initial hydrolysis of 1 h and included a sodium citrate supplement of 10 g/l, an L-lactic acid concentration of 141.5 g/l was obtained after 30 h, with a volumetric productivity of 4.7 g/l/h. The conversion efficiency and product yield were 93.6% of the theoretical lactic acid yield and 52.4 g lactic acid/l00 g Jerusalem artichoke flour, respectively. Such a high concentration of lactic acid with a high productivity from Jerusalem artichokes has not been reported previously, making G-02 a potential candidate for the economic production of L-lactic acid from Jerusalem artichokes on a commercial scale.

Chemopreventive Potential of Angelicae gigantis Radix Aqua-acupuncture Solution (당귀 약침액의 암예방 효과)

  • 김영기;조경희;손윤희;최혜경;김소연;임종국;남경수
    • YAKHAK HOEJI
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    • v.44 no.3
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    • pp.283-292
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    • 2000
  • Angelicae gigantis Radix aqua-acupuncture solution (AGRAS) and Angelicae gigantis Radix water-extracted solution (AGRWS) were prepared and tested for their organ toxicities and chemopreventive potentials. The organ-toxicity of AGRAS to male ICR mice was studied by the measurements of glutamic oxaloacetic transaminase (GOT), glutamic pyruvate transaminase (GPT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP-s) activities after injection of AGRAS for 7 days. The activities of GOT GPT and LDH were decreased, but the activity of ALP-s was not changed with AGRAS. When AGRAS was administered once daily for 10 days before the tumor implantation, AGRAS exerted antitumor activity by inhibiting the growth of Ehrich ascites tumor cells (EATC) in viva. The inductions of quinone reductase (QR), glutathione (GSH) and glutathione S-transferase (GST) and inhibition of polyamine metabolism were tested for the chemopreventive potentials of AGRAS and AGRWS. AGRAS was potent inducer of QR activity in murine hepatoma Hepalclc7 cells. In cultured rat Ac2F cells, AGRAS was also significantly induced QR activity GSH levels were increased about 1.3 fold with AGRAS. In addition the activity of GST was increased about 2.5 fold with AGRAS at the concentration of $0.1{\;}{\times}{\;}$. The effects of AGRAS and AGRWS were tested on the growth of Acanthamoeba castellanii. Proliferation of Acanthamoeba castellanii in a broth medium was inhibited by AGRAS and AGRWS at the concentration of $1{\;}{\times}{\;}and{\;}5{\;}{\times}{\;}$, respectively: These results suggest that AGRAS has chemopreventive potential by inducing QR activity increasing GSH and GST levels and inhibition of polyamine metabolism.

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Screening of Monocyte Chemoattractant Protein-1-Induced Chemotaxis Inhibitors from Medicinal Herbs (생약자원으로부터 Monocyte Chemoattractant Protein-1에 의한 Chemotaxis 저해활성 검색)

  • Lee, Seung-Woong;Kwon, Oh-Eok;Chung, Mi-Yeon;Kim, Young-Ho;Lee, Hyun-Sun;Kim, Young-Kook;Rho, Mun-Chual
    • Korean Journal of Pharmacognosy
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    • v.33 no.4 s.131
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    • pp.352-358
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    • 2002
  • Blood monocytes are the precursors for the lipid-laden foam cells of early atherosclerotic lesions. Monocyte chemoattractant protein-1(MCP-1), a CC chemokine, and chemokine receptor 2 (CCR2) play a crucial role in the recruitment of monocytes to the vascular lesion. Using the human monocyte THP-1 cell line, we investigate the inhibitory effects of methanol extracts of 127 medicinal herbs on MCP-1 induced chemotaxis. Seven kinds of methanol extracts of medicinal herbs showed above 40% inhibitory effect with the concentration of $25{\mu}g/ml$. They were divide three fractions of $CHCI_3$, BuOH, $H_2O$ to use solvent partition. Among them, butanol extract of Junci Medulla and $CHCI_3$ extract of Clematidis Radix are showed significant inhibitory activities (above 50% inhibition) at the same concentration.

Manassantin A and B Isolated from Saururus chinensis Inhibit $TNF-{\alpha}-Induced$ Cell Adhesion Molecule Expression of Human Umbilical Vein Endothelial Cells

  • Kwon Oh Eok;Lee Hyun Sun;Lee Seung Woong;Chung Mi Yeon;Bae Ki Hwan;Rho Mun-Chual;Kim Young-kook
    • Archives of Pharmacal Research
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    • v.28 no.1
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    • pp.55-60
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    • 2005
  • Leukocyte adhesion to the vascular endothelium is a critical initiating step in inflammation and atherosclerosis. We have herein studied the effect of manassantin A (1) and S (2), dineolignans, on interaction of THP-1 monocytic cells and human umbilical vein endothelial cells (HUVEC) and expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in HUVEC. When HUVEC were pretreated with 1 and 2 followed by stimulation with $TNF-{\alpha}$, adhesion of THP-1 cells to HUVEC decreased in dose-dependent manner with $IC_{50}$ values of 5 ng/mL and 7 ng/mL, respectively, without cytotoxicity. Also, 1 and 2 inhibited $TNF-{\alpha}-induceda$ up-regulation of ICAM-1, VCAM-1 and E-selectin. The present findings suggest that 1 and 2 prevent monocyte adhesion to HUVEC through the inhibition of ICAM-1, VCAM-1 and E-selectin expression stimulated by $TNF-\alpha$, and may imply their usefulness for the prevention of atherosclerosis relevant to endothelial activation.

Roles of the Residues Lys115 and Tyr116 in the Binding of an Allosteric Inhibitor AMP to Pea Cytosolic Fructose-1,6-bisphosphatase

  • Jang, Hye-Kyung;Cho, Man-Ho;Kwon, Yong-Kook;Bhoo, Seong-Hee;Jeon, Jong-Seong;Hahn, Tae-Ryong
    • Journal of Applied Biological Chemistry
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    • v.51 no.2
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    • pp.45-49
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    • 2008
  • Cytosolic fructose-1,6-bisphosphatase (cFBPase) in plants is a key regulatory enzyme in the photosynthetic sucrose biosynthesis. Plant cFBPases, like the mammalian FBPases, are inhibited by adenosine 5'-monophosphate (AMP) and fructose-2,6-bisphosphate (Fru-2,6-$P_2$). In the mammalian FBPases, Lys112 and Tyr113 play important roles in the AMP binding. To understand roles of the corresponding residues, Lys115 and Tyr116, in pea cFBPase, the mutant cFBPases were generated by site-directed mutagenesis. The alterations of Lys115 to Gin and Tyr116 to Phe displayed small changes in $K_m$ and $K_i$ for Fru-2,6-$P_2$, indicating that the mutation causes minor effects on the enzyme catalysis and Fru-2,6-$P_2$ binding, whereas resulted in higher than 500-fold increase of $[AMP]_{0.5}$ compared with that of the wild-type enzyme. Results indicate the residues Lys115 and Tyr116 play important roles in the binding of AMP to the allosteric site of the pea cFBPase.

EFFECTS OF INHIBITORY DRUGS ON THE ARACHIDONIC ACID METABOLISM OF PERIODONTAL TISSUE (치은 Arachidonic acid 대사산물의 억제약물에 관한 실험적 연구)

  • Han, Se-Hee;Oh, Kwi-Ok;Kim, Hyung-Seop
    • Journal of Periodontal and Implant Science
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    • v.23 no.2
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    • pp.243-259
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    • 1993
  • The bone resorbing activity of $PGE_2$ and elevated level of prostaglandins(PGs) and thromboxanes (TXs) in inflamed gingiva which are cyclooxygenase(C) metabolites have been well documented. Nonsteroidal anti-inflammatory drugs(NSAIDs) have been known to suppress gingival inflammation and bone resorption through the specific inhibitory action on the C pathway thereby decrease of various C metabolites. Recent studies provide unequivocal results that gingival tissue metabolizes arachidonic acid(AA) mainly through lipoxygenase(L) pathway. And the results of our previous experiments suggest that indomethacin may have inhibitory action on L as well as C. Thus we started this study to show the influences of several C inhibitors on the L activity at therapeutic and toxic dosage. Periodontal tissue samples were obtained from patients with advanced periodontitis and incubated with $^{14}C-AA(0.2{\mu}Ci)$ and various enzyme inhibitors. The tissue lipid extracts were separated by means of thin layer chromatography(TLC) and analyzed by means of autoradiography and TLC analyzer. Our results showed that aspirin inhibited C more selectively than L, however at higher concentration it also decreased HETEs production significantly. Indomethacin showed dose-dependent inhibition of L as well as C and all of the L metabolites were decreased to the same degree by high concentration of indomethacin. AA-861, which is an experimental tool of selective L inhibitor, showed inhibition of HETEs production but no effect on the production of $TXB_2$, PGs and $LTB_4$. Various propionic acid derivatives NSAIDs(ibuprofen, flurbiprofen, naproxen) showed the same patterns of effect on AA metabolism each other that was profound inhibition of PGs production, to the less degree HETEs and $TXB_2$ production, and of no effect on the $LTB_4$ production.

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Inhibition of Cytochrome P450 by Propolis in Human Liver Microsomes

  • Ryu, Chang Seon;Oh, Soo Jin;Oh, Jung Min;Lee, Ji-Yoon;Lee, Sang Yoon;Chae, Jung-woo;Kwon, Kwang-il;Kim, Sang Kyum
    • Toxicological Research
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    • v.32 no.3
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    • pp.207-213
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    • 2016
  • Although propolis is one of the most popular functional foods for human health, there have been no comprehensive studies of herb-drug interactions through cytochrome P450 (CYP) inhibition. The purpose of this study was to determine the inhibitory effects of propolis on the activities of CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1 and 3A4 using pooled human liver microsomes (HLMs). Propolis inhibited CYP1A2, CYP2E1 and CYP2C19 with an $IC_{50}$ value of 6.9, 16.8, and $43.1{\mu}g/mL$, respectively, whereas CYP2A6, 2B6, 2C9, 2D6, and 3A4 were unaffected. Based on half-maximal inhibitory concentration shifts between microsomes incubated with and without nicotinamide adenine dinucleotide phosphate, propolis-induced CYP1A2, CYP2C19, and CYP2E1 inhibition was metabolism-independent. To evaluate the interaction potential between propolis and therapeutic drugs, the effects of propolis on metabolism of duloxetine, a serotonin-norepinephrine reuptake inhibitor, were determined in HLMs. CYP1A2 and CYP2D6 are involved in hydroxylation of duloxetine to 4-hydroxy duloxetine, the major metabolite, which was decreased following propolis addition in HLMs. These results raise the possibility of interactions between propolis and therapeutic drugs metabolized by CYP1A2.

Effects of Silibinin on the Pharmacokinetics of Carvedilol after Oral Administration in Rats

  • Lee, Chong-Ki;Choi, Jun-Shik
    • Journal of Pharmaceutical Investigation
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    • v.41 no.3
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    • pp.153-159
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    • 2011
  • This study was designed to investigate the effects of silibinin on the pharmacokinetics of carvedilol after oral administration of carvedilol in rats. Carvedilol was administered orally (3 mg/kg) with oral silibinin (0.3, 1.5 or 6 mg/kg) and intravenously (1 mg/kg) to rats. The effects of silibinin on P-glycoprotein (P-gp) and cytochrome P450 (CYP) 2C9 and CYP2D6 activity were also evaluated. Silibinin inhibited CYP2C9 and CYP2D6 enzyme activity with 50% inhibition concentration ($IC_{50}$) of 5.2 ${\mu}M$ and 85.4 ${\mu}M$, respectively. In addition, silibinin significantly enhanced the cellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp. Compared with the control group, the area under the plasma concentration-time curve was significantly increased by 36.3-57.1%, and the peak concentration was significantly increased by 51.1-88.5% in the presence of silibinin after oral administration of carvedilol. Consequently, the relative bio-availability of carvedilol was increased by 1.13- to 1.57-fold and the absolute bioavailability was significantly increased by 38.6-59.7%. The time to reach peak concentration and the terminal half-life were not significant. The enhanced oral bio-availability of carvedilol may result from inhibition of CYP2C9-mediated metabolism and P-gp-mediated efflux of carvedilol rather than inhibition of CYP2D6-mediated metabolism in the intestine and/or in the liver by silibinin.

Inhibition of Adventitious Root Growth in Boron-Deficient or Aluminum-Stressed Sunflower Cuttings

  • Hong, Jung-Hee;Go, Eun-Jung;Kim, Tae-Yun
    • Journal of Environmental Science International
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    • v.12 no.11
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    • pp.1189-1196
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    • 2003
  • The effect of boron and aluminum on the development of adventitious roots was studied in sunflower cuttings. Three-day-old seedlings were de-rooted and grown in nutrient solutions with or without boron and supplemented with different concentrations (from 50 to 700 ${\mu}$M) of aluminum. The number and length of the adventitious roots and proline content in adventitious roots in response to insufficient boron and aluminum stress were determined periodically. The micronutrient boron caused the development of numerous roots in the lower parts of the hypocotyl. A dose-response of boron-induced rooting yielded an optimum concentration of 0.1 mM boron. In the absence of boron, in the majority of the adventitious roots, a significant inhibition was observed with or without aluminum, indicating that the most apparent symptom of boron deficiency is the cessation of root growth. Increasing concentrations of aluminum caused progressive inhibition of growth and rooting of the hypocotyls, and a parallel increase in proline levels of adventitious roots. Supplemental boron ameliorated the inhibitory effect of aluminum, suggesting that aluminum could inhibit root growth by inducing boron deficiency. Ascorbate added to medium in the absence of boron improved root growth and induced a significant decrease in proline levels. These findings suggest that adventitious root growth inhibition resulting from either boron deficiency or aluminum toxicity may be a result of impaired ascorbate metabolism.

GBA inhibition suppresses ovarian cancer growth, survival and receptor tyrosine kinase AXL-mediated signaling pathways

  • Gang Wang;Baisha Ouyang;Fang Jing;Xiaoyan Dai
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.1
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    • pp.21-29
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    • 2023
  • The poor outcome of advanced ovarian cancer under conventional therapy necessitates new strategies to improve therapeutic efficacy. β-glucosidase (encoded by GBA) is a lysosomal enzyme and is involved in sphingolipids metabolism. Recent studies revealed that β-glucosidase plays a role in cancer development and chemoresistance. In this work, we systematically evaluated the expression and role of GBA in ovarian cancer. Our work demonstrates that inhibition of β-glucosidase has therapeutic potential for ovarian cancer. Gene Expression Profiling Interactive Analysis database, western blot and immunohistochemistry analyses of patient samples demonstrated that GBA mRNA and protein expression levels were significantly increased in ovarian cancer compared to normal tissues. Functional studies using gainof-function and loss-of-function approaches demonstrated that GBA overexpression did not affect growth and migration but alleviated cisplatin's efficacy in ovarian cancer cells. In addition, GBA depletion resulted in growth inhibition, apoptosis induction, and enhancement of cisplatin's efficacy. Of note, we found that GBA inhibition specifically decreased receptor tyrosine kinase AXL level, leading to the suppression of AXL-mediated signaling pathways. Our data suggest that GBA represents a promising target to inhibit AXL signaling and overcome cisplatin resistance in ovarian cancer.