Leukotrienes (LTs) are known to act as a mediator provoking tissue response in inflammation. LTs, particularly type B4 (LTB4) as chemotactic factor of neutrophil are released from neutrophils and gastric mucosal cells when these cells are stimulated by Helicobacter pylori. The present study was performed to test a possibility that eupatilin may prevent the H. pylori-induced gastric cell damage by observing whether this chemical inhibit the release of LTB4 from H. pylori-stimulated gastric cells (Kato III) and neutrophils. As observed in the previous study, H. pylori induced the release of LTB4 from these cells and at the same influx of Ca2+ into the cells. In the presence of eupatilin, the release of LTB4 was inhibited whereas Ca2+ influx was not affected. Probably eupatilin may inhibit the release of LTB4 by preventing the synthesis of LTs. These results suggest that eupatilin can has a therapeutic effect on H. pylori-induced gasric cell damage.
Helicobacter pylori* ; Helicobacter* ; Inflammation ; Leukotriene B4* ; Leukotrienes ; Neutrophils*

BACKGROUND: Theophylline has been used in the treatment of asthma for decades as a broncho- dilator, but recent studies suggested that it has anti-inflammatory and immunomodulatory properties. OBJECTIVE: The aim of this study was to determine the effect of theophylline therapy on urinary excretion of leukotriene B4 (LTB4) and C4 (LTC4), which have been known to play a role in the airway inflammation in asthmatic patients. METHODS: Fifty-one patients, aged 13 months to 6 years, who were hospitalized with asthma were randomized in to 3 groups according to treatment regimen. Twenty-one patients were administered theophylline with budesonide and salbutamol inhalation (Group 1). Fifteen patients were treated with budesonide and salbutamol inhalation (Group 2) and the other fifteen patients with salbutamol inhalation only (Group 3). Urine samples for the determination of LTB4 and LTC4 were collected on admission and on the fifth hospital day in each patient. The concentrations of urinary leukotrienes were measured by ELISA (Neogen, U.S.A.) and corrected by urinary creatinine levels. Ten controls were also studied. RESULTS: The initial urinary LTC4 levels in asthmatic children were significantly higher than in controls. Urinary LTC4 was significantly decreased after treatment compared with the initial level in group 1 (p<0.05), but not in groups 2 and 3. Urinary LTB4 did not show significant difference between patients and controls on admission and showed no significant change after treatment compared with the initial levels in all three groups. CONCLUSION: These results suggest that the suppression of LTC4 synthesis is one of the anti-inflammatory mechanisms of theophylline and support the use of theophylline as a the rapeutic agent in asthmatic patients.
Albuterol ; Asthma* ; Budesonide ; Child* ; Creatinine ; Enzyme-Linked Immunosorbent Assay ; Humans ; Inflammation ; Inhalation ; Leukotriene B4* ; Leukotriene C4 ; Leukotrienes ; Theophylline*

OBJECTIVETo observe the effect of montelukast treatment on levels of serum leukotriene B4 and urinary leukotriene E4 in infants with bronchiolitis.

METHODSSeventy-five children who were diagnosed with bronchiolitis between June 2014 and December 2014 were randomly assigned into two groups, one with thirty-eight cases as the montelukast treatment group and another thirty-seven cases as the control group. All of the children were given routine medical treatment. The children in the montelukast treatment group were additionally given montelukast daily (4 mg once a day, for 7 days). The serum leukotriene B4 and urinary leukotriene E4 levels were measured using ELISA before and after treatment. The relationship between serum leukotriene B4 and urinary leukotriene E4 levels was analyzed by Peason correlation analysis.

RESULTSAfter 7 days of treatment, the serum leukotriene B4 and urinary leukotriene E4 levels in the montelukast treatment and control groups were significantly reduced compared with before treatment (P<0.05). The montelukast treatment group showed significantly lower serum leukotriene B4 and urinary leukotriene E4 levels than the control group (P<0.05). The remission time of cough, wheezing and lung wheezes and the length of hospital stay in the montelukast treatment group were significantly shortened compared with the control group (P<0.05). There was a positive correlation between serum leukotriene B4 and urinary leukotriene E4 levels (r=0.723, P<0.05).

CONCLUSIONSMontelukast has a reliable clinical curative efficacy for bronchiolitis in infants, possibly by decreasing serum leukotriene D4 and urinary leukotriene E4 levels.

Acetates ; therapeutic use ; Bronchiolitis ; drug therapy ; metabolism ; Humans ; Infant ; Leukotriene B4 ; blood ; Leukotriene E4 ; urine ; Quinolines ; therapeutic use

PURPOSE: There has recently been increasing interest in the use of exhaled breath condensate (EBC) as a simple noninvasive means for understanding the physiology of asthma. The aim of this study was to evaluate the levels of leukotriene B4 (LTB4) and eosinophil cationic protein (ECP) in the EBC of asthmatic children. METHODS: We measured LTB4 and ECP levels in EBC from children aged 6-14 years, including healthy children (n=25) and asthmatic children (n=25). We also measured serum LTB4 and serum ECP. Pulmonary function tests and methacholine challenge tests were performed on all subjects. RESULTS: Exhaled LTB4 levels were increased significantly in patients with asthma compared to normal subjects (7.1+/-3.7 pg/mL vs. 2.2+/-1.7 pg/mL, P<0.05). Serum LTB4 levels were not significantly different in patients with asthma compared to normal subjects (674.7+/-484.1 pg/mL vs. 487.1+/-272.0 pg/mL, P=0.156,) and no significant correlations were found between exhaled and serum LTB4 concentrations in children with asthma (r=0.052, P=0.758). Exhaled ECP levels were not significantly different in patients with asthma compared to normal subjects (P=0.419). Serum ECP levels were significantly increased in patients with asthma compared to normal subjects (44.37+/-32.14 microg/L vs. 16.40+/-13.23 microg/L, P=0.001). CONCLUSION: We found significantly elevated LTB4 levels in the EBC of asthmatic children. Our results suggest that EBC may be one of the supportive tools to measure airway inflammation in children with asthma.
Asthma ; Child* ; Eosinophil Cationic Protein ; Humans ; Inflammation ; Leukotriene B4 ; Methacholine Chloride ; Physiology ; Respiratory Function Tests

Leukotrienes (LTs) are known to act as a mediator provoking tissue response in inflammation. This finding implicates that LTs also play important roles in the pathogenesis of H. pylori-induced gastritis and gastric ulceration. Rebamipide is being currently used as a therapeutics for gastritis and peptic ulcer, but their mechanisms of action have not been known clearly yet. One possibility is that their therapeutic effects are ascribed to interfering with the H. pylori-induced release of LTs from neutrophils and gastric mucosal cells. In the present study, this possibility was tested using LTB4 as the test material in human neutrophils and Kato III cells(gastric adenoma cells as a substitute for gastric mucosal cells). The release of LTB4 from both neutrophils and Kato III cells was time and H. pylori-dose dependent. The maximum release of LTB4 was induced by neutrophils and Kato III cells when these cells incubated with H. pylori 4.8 X 108 cells/ml for 30 min. But in the presence of rebamipide the release of LTB4 from these cells was suppressed in dose dependent manners. The release was completely suppressed at 1.0 mM of rebamipide in neutrophils and 2.0 mM of this drug in Kato III cells, respectively. We also obtained the results that the release of LTB4 was induced by A23187 (Ca2+ ionophore) and the A23187-induced release was also inhibited by rebamipide. It seems that the mechanism of action of rebamipide is through its interaction with the level of intracellular Ca2+. In view of the roles of LTB4 in inflammatory reaction and the roles of H. pylori in gastritis and peptic ulcer, the effects of this drug observed in this study may contribute to their therapeutic action in these gastric disorders.
Adenoma ; Calcimycin ; Gastritis ; Helicobacter pylori* ; Helicobacter* ; Humans ; Inflammation ; Leukotriene B4* ; Leukotrienes ; Neutrophils ; Peptic Ulcer ; Stomach Ulcer

OBJECTIVE: To explore the expression patterns, prognostic implications, and biological role of leukotriene B4 receptor (LTB4R) in patients with acute myeloid leukemia (AML). METHODS: We collected the data of mRNA expression levels and clinical information of patients with AML from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database for mRNA expression analyses, survival analyses, Cox regression analyses and correlation analyses using R studio to assess the expression patterns and prognostic value of LTB4R. The correlation of LTB4R expression levels with clinical characteristics of the patients were analyzed using UALCAN. The co-expressed genes LTB4R were screened from Linkedomics and subjected to functional enrichment analysis. A protein-protein interaction network was constructed using STRING. GSEA analyses of the differentially expressed genes (DEGs) were performed based on datasets from TCGA-LAML stratified by LTB4R expression level. We also collected peripheral blood mononuclear cells (PBMCs) from AML patients and healthy donors for examination of the mRNA expression levels of LTB4R and immune checkpoint genes using qRT-PCR. We also examined serum LTB4R protein levels in the patients using ELISA. RESULTS: The mRNA expression level of LTB4R was significantly increased in AML patients (4.898±1.220 vs 2.252±0.215, P < 0.001), and an elevated LTB4R expression level was correlated with a poor overall survival (OS) of the patients (P=0.004, HR=1.74). LTB4R was identified as an independent prognostic factor for OS (P=0.019, HR=1.66) and was associated with FAB subtypes, cytogenetic risk, karyotype abnormalities and NPM1 mutations. The co- expressed genes of LTB4R were enriched in the functional pathways closely associated with AML leukemogenesis, including neutrophil inflammation, lymphocyte activation, signal transduction, and metabolism. The DEGs were enriched in differentiation, activation of immune cells, and cytokine signaling. Examination of the clinical serum samples also demonstrated significantly increased expressions of LTB4R mRNA (P=0.044) and protein (P=0.008) in AML patients, and LTB4R mRNA expression was positively correlated with the expression of the immune checkpoint HAVCR2 (r= 0.466, P=0.040). CONCLUSION LTB4R can serve as a novel biomarker and independent prognostic indicator of AML and its expression patterns provide insights into the crosstalk of leukemogenesis signaling pathways involving tumor immunity and metabolism.
Humans ; Leukemia, Myeloid, Acute/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Prognosis ; RNA, Messenger/metabolism* ; Receptors, Leukotriene B4/genetics*

Mast cells are major immune cells in allergy to secrete allergic mediators by a degranulation process and make and secrete inflammatory lipids and cytokines in response to antigen stimulation. An amino acid tryptophan regulates immune functions. Tryptophan ameliorates inflammatory colitis in which mast cells are engaged. However, its effects on mast cells remain to be solved. We investigated the effect of tryptophan on IgE-mediated allergic responses in the mast cells and mice. IgE-mediated passive cutaneous anaphylaxis (PCA) in mice were examined. Also IgE-mediated mast cell activation responses such as degranulation of stored granules and secretion of inflammatory lipid LTB₄ and cytokines (TNF-α and IL-4) were measured. Intraperitoneal administration of tryptophan suppressed PCA in mice. Also, in the cellular level tryptophan inhibited IgE-mediated mast cell activation such as IgE-mediated degranulation and the production of LTB₄. Also, it inhibited production of inflammatory cytokines TNF-α and IL-4. In summary, tryptophan suppressed IgE-mediated allergic activation in vivo and in vitro. Tryptophan supplementation is beneficial for IgE-mediated allergy.
Animals ; Colitis ; Cytokines ; Hypersensitivity ; Immunoglobulin E ; In Vitro Techniques ; Interleukin-4 ; Leukotriene B4 ; Mast Cells* ; Mice ; Passive Cutaneous Anaphylaxis ; Tryptophan*

Recently, single-nucleotide polymorphisms (SNPs) in G-protein-coupled receptors (GPCRs) have been suggested to contribute to physiopathology and therapeutic effects. Leukotriene B4 receptor 2 (BLT2), a member of the GPCR family, plays a critical role in the pathogenesis of several inflammatory diseases, including cancer and asthma. However, no studies on BLT2 SNP effects have been reported to date. In this study, we demonstrate that the BLT2 SNP (rs1950504, Asp196Gly), a Gly-196 variant of BLT2 (BLT2 D196G), causes enhanced cell motility under low-dose stimulation of its ligands. In addition, we demonstrated that Akt activation and subsequent production of reactive oxygen species (ROS), both of which act downstream of BLT2, are also increased by BLT2 D196G in response to low-dose ligand stimulation. Furthermore, we observed that the ligand binding affinity of BLT2 D196G was enhanced compared with that of BLT2. Through homology modeling analysis, it was predicted that BLT2 D196G loses ionic interaction with R197, potentially resulting in increased agonist-receptor interaction. To the best of our knowledge, this report is the first to describe a SNP study on BLT2 and shows that BLT2 D196G enhances ligand sensitivity, thereby increasing cell motility in response to low-dose ligand stimulation.
Asthma ; Cell Movement* ; Humans ; Ligands ; Reactive Oxygen Species ; Receptors, G-Protein-Coupled ; Receptors, Leukotriene B4 ; Therapeutic Uses

STUDY DESIGN: The motor impairment and sensory dysfunction were evaluated in twenty-eight rats after dropping of leukotriene B4 and thromboxane B2 on lumbar nerve roots. OBJECTIVES: To evaluate the effects of inflammatory products on lumbar nerve roots of the rats without mechanical compression. MATERIALS AND METHODS: Twenty-eight Sprague-Dawley rats were evenly divided into four groups (7 rats in each group) according to the substances applied: In group I (sham operation), even dropping of normal saline on left 4th, 5th and 6th lumbar nerve roots: In group II, leukotriene B4; In group III, thromboxane B2: In group IV, leukotriene B4 and thromboxane B2. All rats were tested at 1st, 3rd, 5th, 7th, 10th and 14th postoperative day for motor impairment and sensory dysfunction to the heat. RESULTS: Hypersensitivity to the heat started to appear at 1st postoperative day in group IV and at 3rd day in groups II and III and was Maximum at 5th day in group III and 7 th day in groups II and IV compared with the control group. The histological study also showed moderate to marked necrosis of ganglion cells and infiltration of the inflammatory cells compared to the control group. CONCLUSION: These results suggest that leukotriene B4 and thromboxane B2 produce inflammatory reactions in or around the nerve roots and lead to thermal hyperalgesia in rats without mechanical copmpression, therefore these results may apply to human lumbar nerve roots.
Animals ; Ganglion Cysts ; Hot Temperature ; Humans ; Hyperalgesia ; Hypersensitivity ; Leukotriene B4* ; Necrosis ; Radiculopathy ; Rats* ; Rats, Sprague-Dawley ; Thromboxane B2*

The purpose of this study is to validate the potential etiologic factors for temporomandibular disorder(TMD). TMJ arthroscopic examination was performed in upper joint compartment of 32 joints from 20 patients with mandibular fractures. Synovial fluid was collected from the upper joint space during pumping manipulation with normal saline. Cytologic smearing and histomorphologic exam of synovial fluid were performed in 15 joints. Prostaglandin E2(PGE2) concentration was measured in 11 joints. Leukotriene B4(LTB4) concentration was measured in 8 joints. There were several arthroscopic variables such as ecchymosis, fibrillation, and adhesion. Histomorphologic exam showed a variety of findings such as bloody smears, cellular cluster, degenerated cells and cartilage, undifferentiated crystal. Mean PGE2 concentrations were 316.5 pg/ml. Mean LTB4 concentrations were 45.9pg/ml. This study demonstrated a variety of findings on inflammatory and degenerative changes of TMJ. Because acute trauma such as mandibular fracture is a major etiologic factor in cartilage degradation and biochemical and intraarticular pathology, clinicians must identify and address TMJ signs and symptoms during follow-up periods in the long term.
Arthroscopy ; Cartilage ; Dinoprostone ; Ecchymosis ; Follow-Up Studies ; Humans ; Joints* ; Leukotriene B4 ; Mandibular Fractures* ; Pathology ; Synovial Fluid ; Temporomandibular Joint*