DA-9601, a standardized extract of Artemisia asiatica, blocks TNF-alpha-induced IL-8 and CCL20 production by inhibiting p38 kinase and NF-kappaB pathways in human gastric epithelial cells.
OBJECTIVE
To investigate whether, or how, DA-9601, which is a new gastroprotective agent, inhibits TNF-alpha-induced inflammatory signals in gastric epithelial AGS cells.


METHODS
Cell viability was determined by MTT assay. IL-8 and CCL20 promoter activities were determined by a luciferase reporter gene assay. NF-kappaB-dependent transcriptional activity was determined by I-kappaB alpha degradation, NF-kappaB p65 nuclear translocation and a luciferase activity assay. IL-8 and CCL20 gene expression and protein secretion were determined by RT-PCR and an enzyme-linked immunosorbent assay (ELISA). Total and phosphorylated forms of mitogen-activated protein kinases (MAPKs) were determined by Western blot.


RESULTS
Treatment of AGS cells with DA-9601 reduced TNF-alpha-induced IL-8 and CCL20 promoter activities, as well as their gene expression and protein release. TNF-alpha also induced NF-kappaB-dependent transcriptional activity in AGS cells. In contrast, in cells treated with DA-9601, TNF-alpha-induced NF-kappaB activity was significantly blocked. Although all three MAP kinase family members were phosphorylated in response to TNF-alpha, a selective inhibitor of p38 kinase SB203580 only could inhibit both NF-kappaB-dependent transcriptional activity and IL-8 and CCL20 production, suggesting a potential link between p38 kinase and NF-kappaB-dependent pathways in AGS cells. Interestingly, DA-9601 also selectively inhibited p38 kinase phosphorylation induced by TNF-alpha.


CONCLUSIONS
DA-9601 blocked TNF-alpha-mediated inflammatory signals by potentially modulating the p38 kinase pathway and/or a signal leading to NF-kappaB-dependent pathways in gastric epithelial cells.
Choi
Suck-Chei
SC
Digestive Disease Research Institute, Wonkwang University School of Medicine, Chonbuk, Korea.
Choi
Eun-Ju
EJ
Oh
Hyun-Mee
HM
Lee
SungGa
S
Lee
Jeong-Kun
JK
Lee
Meung-Su
MS
Shin
Yong-Il
YI
Choi
Suck-Jun
SJ
Chae
Jeong-Ryong
JR
Lee
Kang-Min
KM
Lee
Won-Jung
WJ
Park
Jae-Sik
JS
Shin
Chang-Yell
CY
Oh
Tae-Young
TY
Jun
Chang-Duk
CD
D019306:Artemisia / Q000737:chemistry; D054418:Chemokine CCL20; D019742:Chemokines, CC / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005753:Gastric Mucosa / Q000166:cytology; D017930:Genes, Reporter; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D019402:Macrophage Inflammatory Proteins / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D015398:Signal Transduction / Q000502:physiology; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
C108355:CCL20 protein, human; D054418:Chemokine CCL20; D019742:Chemokines, CC; C116959:DA 9601; D004791:Enzyme Inhibitors; D016209:Interleukin-8; D019402:Macrophage Inflammatory Proteins; D016328:NF-kappa B; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases