Astragalus mongholicus polysaccharide inhibits lipopolysaccharide-induced production of TNF-alpha and interleukin-8.
OBJECTIVE
To explore the effect of Astragalus mongholicus polysaccharide (APS) on gene expression and mitogen-activated protein kinase (MAPK) transcriptional activity in intestinal epithelial cells (IEC).


METHODS
IEC were divided into control group, lipopolysaccharide (LPS) group, LPS+ 50 microg/mL APS group, LPS+ 100 microg/mL APS group, LPS+ 200 microg/mL APS group, and LPS+ 500 microg/mL APS group. Levels of mRNAs in LPS-induced inflammatory factors, tumor necrosis factor (TNF)-alpha and interleukin (IL)-8, were measured by reverse transcription-polymerase chain reaction. MAPK protein level was measured by Western blotting.


RESULTS
The levels of TNF-alpha and IL-8 mRNAs were significantly higher in IEC with LPS-induced damage than in control cells. APS significantly abrogated the LPS-induced expression of the TNF-alpha and IL-8 genes. APS did not block the activation of extracellular signal-regulated kinase or c Jun amino-terminal kinase, but inhibited the activation of p38, suggesting that APS inhibits LPS-induced production of TNF-alpha and IL-8 mRNAs, possibly by suppressing the p38 signaling pathway.


CONCLUSIONS
APS-modulated bacterial product-mediated p38 signaling represents an attractive strategy for prevention and treatment of intestinal inflammation.
Yuan
Yuan
Y
Department of Pediatrics, Shengjing Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, China.
Sun
Mei
M
Li
Ke-Shen
KS
D000818:Animals; D027883:Astragalus Plant / Q000737:chemistry*; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D016209:Interleukin-8 / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008070:Lipopolysaccharides; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors*
D016209:Interleukin-8; D008070:Lipopolysaccharides; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases