interleukin-8 and ecabet

Helicobacter pylori stimulates nuclear factor-kappa B (NF-kappa B) activation and chemokine interleukin-8 (IL-8) expression in gastric epithelial cells. Ecabet sodium (ecabet), a locally acting antiulcer drug, is known to have anti-H. pylori activity. However, there is little understanding of how ecabet induces anti-inflammatory activity in gastric epithelial cells infected with H. pylori. The aim of this study was to investigate the effects of ecabet on IL-8 gene expression and NF-kappa B activation in human gastric epithelial cells infected with H. pylori.. After Hs746T, MKN-45, or SNU-5 gastric epithelial cell lines had been infected with cagA+cytotoxin+H. pylori in the presence of ecabet, IL-8 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction, and IL-8 secretion was measured by enzyme-linked immunosorbent assay. NF-kappa B and inhibitory kappa B-alpha (I kappa B alpha) signals were assayed by electrophoretic mobility shift assay and Western blot, respectively. The activation of NF-kappa B and IL-8 reporter genes was determined by luciferase assay.. Ecabet showed no antimicrobial activiy against Gram-positive or -negative bacteria. However, ecabet inhibited transcription of the IL-8 gene and secretion of IL-8 by gastric epithelial cells infected with H. pylori at a concentration of 5 micro g/ml. Moreover, ecabet inhibited the activation of NF- kappa B and the degradation of I kappa B alpha in gastric epithelial cells in response to H. pylori infection. In addition, the NF-kappa B signal inhibited by ecabet was comprised predominantly of heterodimers of p65/p50.. Ecabet inhibited H. pylori-induced IL-8 gene transcription and secretion by suppressing the NF-kappa B signal. This inhibition might be one pathway by which ecabet exerts its anti-inflammatory effect on H. pylori-induced gastric inflammation.

Topics: Abietanes; Blotting, Western; Cell Line; Electrophoretic Mobility Shift Assay; Epithelial Cells; Gastric Mucosa; Gene Expression Regulation; Genes, Reporter; Helicobacter pylori; Humans; I-kappa B Proteins; Interleukin-8; Luciferases; Microbial Sensitivity Tests; NF-kappa B; NF-KappaB Inhibitor alpha; RNA, Messenger; Transcription, Genetic

The pathogenic role of human neutrophils has been implicated in Helicobacter pylori-associated gastritis. Ecabet sodium, a locally acting antiulcer drug, has anti-H. pylori actions. The aim of this study was to examine the effects of ecabet on the ability of H. pylori to stimulate human neutrophils. H. pylori were added to 1 x 10(5) neutrophils and incubated for 30 min in the presence of ecabet. Bacterial suspensions which had been incubated with ecabet for 30 min were also used to stimulate neutrophils. The intracellular production of reactive oxygen species was measured with a FACScan. Bacterial suspensions were also added to neutrophils in the presence of ecabet and incubated at 37 degrees C for 12 h to measure interleukin (IL)-8 production by enzyme-linked immunosorbent assay. The mean fluorescence intensity was found to be attenuated dose-dependently by ecabet (P < 0.01). Ecabet also inhibited IL-8 production by neutrophils in a dose-dependent manner (P < 0.001). Bacteria with prior incubation with ecabet induced significantly lower IL-8 production than those without this incubation (P < 0.05). Ecabet sodium has preventive effects on the ability of H. pylori to stimulate human neutrophils. It may lead to reduced gastritis activity and decreased oxidative damage of the gastric mucosa in H. pylori-associated gastritis.

Topics: Abietanes; Anti-Bacterial Agents; Anti-Ulcer Agents; Diterpenes; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Helicobacter Infections; Helicobacter pylori; Humans; Interleukin-8; Luminescent Measurements; Neutrophils; Reactive Oxygen Species