Astragalus mongholicus polysaccharide inhibits lipopolysaccharide-induced production of TNF-α and interleukin-8

AIM： To explore the effect of Astraga/us mongholicus polysaccharide （APS） on gene expression and mitogenactivated protein kinase （MAPK） transcriptional activity in intestinal epithelial cells （IEC）. METHODS： IEC were divided into control group, lipopolysaccharide （LPS） group, LPS＋ 50 μg/mL APS group, LPS＋ 100 μg/mL APS group, LPS＋ 200 μg/mL APS group, and LPS＋ 500 μg/mL APS group. Levels of mRNAs in LPS-induced inflammatory factors, tumor necrosis factor （TNF）-α 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-α 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-α 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-α and IL-8 mRNAs, possibly by suppressing the p38 signaling pathway.CONCLUSION： APS-modulated bacterial productmediated p38 signaling represents an attractive strategy for prevention and treatment of intestinal inflammation.