• Title/Summary/Keyword: leukotrienes

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EFFECTS OF PANAX GINSENG SAPONINS ON CHEMICAL MEDIATOR RELEASE FROM AIRWAY SMOOTH MUSCLE IN ACTIVELY SENSITIZED GUINEA PIG

  • Ro Jai Youl;Yoon Suk Jong;Lee Jong Wha;Kim Kyung Hwan
    • Proceedings of the Ginseng society Conference
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    • 1993.09a
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    • pp.84-93
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    • 1993
  • It has been reported that ginseng is effective in the central nervous system, immune system, and the strong inflammatory responses. However, there has been no research report yet about the effect of ginseng on allergic hypersensitivity reactivity. To confirm the ginseng effects on the release of mediators(histamine. leukotrienes etc.) which cause the hypersensitivity reactivity and inflammatory response, we used actively sensitized guinea pig airway tissues by utilizing the superfusion technique. In this procedure. the contractile response and mediators released after antigen stimulation of sensitized tissues, and IgG and IgE antibody products were measured in sera of immunized animals. Then the results of the controll group were compared to those of ginseng pretreatment groups. In the total saponin(TS) and panaxatriol(PT) pretreatment, histamine release decreased by $20\%$ in the tracheal tissues after active sensitization by ovalbumin(OVA, 10mg/kg), but in the lung parenchyma, histamine release decreased by $40\%.$ Panaxadiol(PD) significantly decreased histamine release by $40\%$ in the both tissues after active sensitization. TS, PT and PD of ginseng poorly blocked leukotrienes (LTs) and prostagrandin $D_2(PGD_2)$ release(less than $10\%$). Ginseng TS and PT had no effect on the serum IgG antibody production by ovalbumin, whereas PD significantly increased serum IgG antibody contents(approximately by 2 times). However, $IgG_1$ antibody products in the serum of guinea pig actively sensitized with ovalbumin after PD pretreatment were decreased, compared to that with ovalbumin alone. IgE antibody production by passive cutaneous anaphylaxis(PCA) titer in the TS pretreatment increased 3 times more than in the absence of TS(PCA titer by PT was not detected). These studies show that some ginseng saponins can in part act to inhibit mediator release in antigen - induced airway smooth muscle by inducing the IgG antibody production which has been changed in the specificity.

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CysLT receptor-mediated NOX2 activation is required for IL-8 production in HMC-1 cells induced by Trichomonas vaginalis-derived secretory products

  • Young Ah Lee;Myeong Heon Shin
    • Parasites, Hosts and Diseases
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    • v.62 no.3
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    • pp.270-280
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    • 2024
  • Trichomoniasis is caused by a sexually transmitted flagellate protozoan parasite Trichomonas vaginalis. T. vaginalis-derived secretory products (TvSP) contain lipid mediators such as leukotriene B4 (LTB4) and various cysteinyl leukotrienes (CysLTs) which included LTC4, LTD4, and LTE4. However, the signaling mechanisms by which T. vaginalis-induced CysLTs stimulate interleukin (IL)-8 production in human mast cells remain unclear. In this study, we investigated these mechanisms in human mast cells (HMC-1). Stimulation with TvSP resulted in increased intracellular reactive oxygen species (ROS) generation and NADPH oxidase 2 (NOX2) activation compared to unstimulated cells. Pre-treatment with NOX2 inhibitors such as diphenyleneiodonium chloride (DPI) or apocynin significantly reduced ROS production in TvSP-stimulated HMC-1 cells. Additionally, TvSP stimulation increased NOX2 protein expression and the translocation of p47phox from the cytosol to the membrane. Pretreatment of HMC-1 cells with PI3K or PKC inhibitors reduced TvSP-induced p47phox translocation and ROS generation. Furthermore, NOX2 inhibitors or NOX2 siRNA prevented CREB phosphorylation and IL-8 gene expression or protein secretion induced by TvSP. Pretreatment with a CysLTR antagonist significantly inhibited TvSP-induced ROS production, CREB phosphorylation, and IL-8 production. These results indicate that CysLT-mediated activation of NOX2 plays a crucial role in ROS-dependent IL-8 production in human mast cells stimulated by T. vaginalis-secreted CysLTs. These findings enhance our understanding of the inflammatory response in trichomoniasis and may inform the development of targeted therapies to mitigate this response.

Homology Modeling of Cysteinyl Leukotriene1 Receptor

  • Babu, Sathya;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.8 no.1
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    • pp.13-18
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    • 2015
  • Cysteinyl leukotrienes are inflammatory mediators having important role in pathophysiological conditions such as asthma, allergic rhinitis and have been implicated in a number of inflammatory conditions including cardiovascular and gastrointestinal diseases. Most of the disease regulatory actions of the CysLTs are mediated through CysLT1 receptor. Hence in the present study, homology modeling of CysLT1 was performed because the availability of 3D structure would enhance the development of new drugs for inflammatory diseases. However the templates identified have low sequence identity which increases the complexity of modeling. Hence, homology modeling was performed using single template, multiple templates and also using threading I-TASSER server. The best model was selected based on the validation of the generated models using Ramachandran and ERRAT plot. The model developed could be useful for identifying crucial residues and docking study.

Role of Cytosolic Phospholipase $A_2$in Cell Injury

  • Kim, Dae-Kyong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.21-22
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    • 2001
  • Phospholipase A$_2$(PLA$_2$) comprise a family of enzymes that hydrolyze the acyl bond at the sn-2 position of phospholipids to generate free fatty acids including arachidonic acid and lysophospholipids. Distinct forms of PLA$_2$are involved in digestion, inflammation, and intercelluar-and intracellular signaling pathways. The released arachidonic acid, which is enriched at the sn-2 position, serves as the precursor for eicosanoids such as prostaglandins and leukotrienes. During oxygenation of arachidonic acid to hydroxy endoperoxide, reactive oxygen radicals are generated. On the other hand, lysophospholipids increase membrane fluidity and can be cytotoxic with its detergent-like action. Thus, the biochemical features of the products of PLA$_2$activity suggest that PLA$_2$may be implicated in many destructive cellular processes.

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Docking Study of Cysteinyl Leukotriene 1 Receptor: Therapeutic Target for Allergy

  • Babu, Sathya
    • Journal of Integrative Natural Science
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    • v.9 no.4
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    • pp.228-233
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    • 2016
  • Cysteinyl leukotrienes are inflammatory mediators having important role in pathophysiological conditions such as asthma and allergic rhinitis. CysLT1 receptor mediates most of the disease regulatory actions of the CysLTs and it is been implicated in a number of inflammatory conditions including gastrointestinal and cardiovascular diseases. Hence in the present study, molecular docking of CysLT1 was performed with its potent and orally efficacious antagonist CP-199330 and CP-199331. The aim of this study was to compare the interaction of CP-199330 and CP-199331 with known drugs such as Zafirlukast, Pranlukast and Montelukast which had already showed clinical efficacy in the treatment of asthma. The residues such as TYR83, GLN274, LYS311 and SER313 were found to interact with both the antagonist and the known drugs. Also, we noticed the docking scores and interaction of the antagonists were comparable with the known drugs. Hence these antagonists could serve as better drugs for the treatment of allergy.

Identification of a novel $Ca^{2+}$-independent Phospholipase $A_2$ in Bovine Brain

  • Jeong, Eui-Man;Jun, Hyung-Jin;Kim, Ha-Dong;Lee, Ho-Sup;Min, Pil-Gi;Jo, Dong-Hwan;Jung, Sung-Yun;Kim, Dea-Kyong
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.102.1-102.1
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    • 2003
  • Phospholipase A$_2$(PLA$_2$) catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid(AA), a precursor of eicosanoids including prostaglandins(PGs) and leukotrienes (LTs). The same reaction also produces lyso-phospholipids. So far, at least 19 enzymes that possess PLA2 activity have been identified, consists of low-molecular-weight, Ca$\^$2+/-requiring, secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, host defense, and atherosclerosis. (omitted)

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20(S)-Protopanaxatriol inhibits release of inflammatory mediators in immunoglobulin E-mediated mast cell activation

  • Kim, Dae Yong;Ro, Jai Youl;Lee, Chang Ho
    • Journal of Ginseng Research
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    • v.39 no.3
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    • pp.189-198
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    • 2015
  • Background: Antiallergic effect of 20(S)-protopanaxatriol (PPT), an intestinal metabolite of ginseng saponins, was investigated in guinea pig lung mast cells and mouse bone marrow-derived mast cells activated by a specific antigen/antibody reaction. Methods: Increasing concentrations of PPT were pretreated 5 min prior to antigen stimulation, and various inflammatory mediator releases and their relevant cellular signaling events were measured in those cells. Results: PPT dose-dependently reduced the release of histamine and leukotrienes in both types of mast cells. Especially, in activated bone marrow-derived mast cells, PPT inhibited the expression of Syk protein, cytokine mRNA, cyclooxygenase-1/2, and phospholipase $A_2$ ($PLA_2$), as well as the activities of various protein kinase C isoforms, mitogen-activated protein kinases, $PLA_2$, and transcription factors (nuclear factor-${\kappa}B$ and activator protein-1). Conclusion: PPT reduces the release of inflammatory mediators via inhibiting multiple cellular signaling pathways comprising the $Ca^{2+}$ influx, protein kinase C, and $PLA_2$, which are propagated by Syk activation upon allergic stimulation of mast cells.

Targeted chiral lipidomics analysis of bioactive eicosanoid lipids in cellular systems

  • Lee, Seon-Hwa;Blair, Ian A.
    • BMB Reports
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    • v.42 no.7
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    • pp.401-410
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    • 2009
  • We have developed a targeted lipidomics approach that makes it possible to directly analyze chiral eicosanoid lipids generated in cellular systems. The eicosanoids, including prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs) and alcohols (HETEs), have been implicated as potent lipid mediators of various biological processes. Enzymatic formations of eicosanoids are regioselective and enantioselective, whereas reactive oxygen species (ROS)-mediated formation proceeds with no stereo-selectivity. To distinguish between enzymatic and non-enzymatic pathways of eicosanoid formation, it is necessary to resolve enantiomeric forms as well as regioisomers. High sensitivity is also required to analyze the eicosanoid lipids that are usually present as trace amounts (pM level) in biological fluids. A discovery of liquid chromatography-electron capture atmospheric pressure chemical ionization/mass spectrometry (LC-ECAPCI/MS) allows us to couple normal phase chiral chromatography without loss of sensitivity. Analytical specificity was obtained by the use of collision-induced dissociation (CID) and tandem MS (MS/MS). With combination of stable isotope dilution methodology, complex mixtures of regioisomeric and enantiomeric eicosanoids have been resolved and quantified in biological samples with high sensitivity and specificity. Targeted chiral lipidomics profiles of bioactive eicosanoid lipids obtained from various cell systems and their biological implications have been discussed.

Functional Imaging of the Multidrug Resistance In Vivo (기능적 영상술을 이용한 다약제 내성의 체내 진단)

  • Lee, Jea-Tae
    • 대한핵의학회:학술대회논문집
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    • 2001.05a
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    • pp.66-75
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    • 2001
  • Although diverse mechanisms are involved in multidrug resistance for chemotherapeutic drugs, the development of cellular P-glycoprotein(Pgp) and multidrug-resistance associated protein (MRP) are important factors in the chemotherapy failure to cancer. Various detection assays provide information about the presence of drug efflux pumps at the mRNA and protein levels. However these methods do not yield information about dynamic function of Pgp and MRP un vivo. Single photon emission tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transport. $^{99m}Tc$-sestaMIBl and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of Pgp-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and N-$[^{11}C]$acetyl-leukotriene E4 provides an opportunity to study MRP function non-invasively in vivo. Results obtained from recent publications are reviewed to confirm the feasibility of using SPECT and PET to study the functionality of MDR transporters in vivo.

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Inhibition of Red Ginseng on 5-Hydroxyeicosatetraenoic Acid (5-HETE) Biosynthesis from Arachidonic Acid in Helicobacter Pylori-infected Gastric Cells

  • Park Soo-Jin
    • Nutritional Sciences
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    • v.9 no.3
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    • pp.152-158
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    • 2006
  • Helicobacter pylori (H. pylori) infection rapidly stimulated either COX-2 or 5-LOX and released arachidonic acid metabolites that have been considered as pivotal mediators in H. pylori-induced inflammatory responses. To determine whether red ginseng extract (RGE) can suppress the biosynthesis of 5(S)-hydroxyeicosatetraenoic acids (HETE), a precursor metabolite of leukotrienes B4 (LTB4) in H. pylori-provoked inflammatory responses in gastric epithelial cells, the biosynthesis of monohydroxy fatty acids was measured using radioactive arachidonic acid and validated by RP-HPLC using non-radioactive AA as substrate in AGS cells cocultured with H. pylori (ATCC 43504) with or without pretreatment of RGE. Among three known major HETEs, H. pylori infection specifically induced the biosynthesis of $^{14}C-5(S)-HETE$ rather than the complex of $^{14}C-15S-/^{14}C-12(S)-HETE$ from $^{14}C-AA$, concomitantly obtained by HPLC(p<0.01). RGE, 1 to $100{\mu}g/ml$, selectively suppressed H. pylori-stimulated $^{14}C-5(S)-HETE$ production implying the attenuation of 5-lipoxygenase activity, of which was similar to known LOX inhibitor NDGA $(10{\mu}M)$ (p<0.01). However, the amount of 5(S)-HETE was significantly reduced by higher dose of RGE $(100{\mu}g/ml)$ (p<0.05). These results indicated that LOX pathway might be one of principle pathogenic mechanisms of H. pylori and red ginseng could be a nutraceutical against H. pylori infection through inhibiting action of LOX activity.