Inhibition of Helicobacter pylori-induced nuclear factor-kappa B activation and interleukin-8 gene expression by ecabet sodium in gastric epithelial cells.
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Kim
Jung Mogg
JM
Department of Microbiology and Institute of Biomedical Science, Hanyang University College of Medicine, Seoul, Korea.
Kim
Joo Sung
JS
Jung
Hyun Chae
HC
Oh
Yu-Kyoung
YK
Kim
Nayoung
N
Song
In Sung
IS
D045784:Abietanes / Q000494:pharmacology*; D015153:Blotting, Western; D002460:Cell Line; D024202:Electrophoretic Mobility Shift Assay; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D016480:Helicobacter pylori / Q000187:drug effects / Q000472:pathogenicity*; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification; D014158:Transcription, Genetic / Q000187:drug effects
D045784:Abietanes; D020672:I-kappa B Proteins; D016209:Interleukin-8; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D012333:RNA, Messenger; D000072000:NF-KappaB Inhibitor alpha; C061681:ecabet; D008156:Luciferases