Effect of Echinacea Polysaccharide on Secretion of TNF-α mRNA by IEC-6 Injured by LPS

紫锥菊多糖对LPS损伤后IEC-6分泌TNF-α mRNA的影响（英文）

Objective] This study was conducted to investigate Echinacea polysaccha-ride （EPS） on expression of tumor necrosis factor （TNF） under injury of intestinal epithelial cel s （lEC-6） by lipopolysaccharide （LPS）, so as to discuss the action mechanism of EPS to injured cel s. [Method] Total DNA was extracted with TRlzon reagent, TNF-α mRNA was amplified, and the amplification products were subjected to agarose gel electrophoresis and imaging. [Result] 50 μg/ml EPS could partial y in-hibited the production of TNF-α mRNA by lEC-6 under the stimulation of LPS, while the inhibition of 200 and 500 μg/ml EPS on the level of TNF-α mRNA gradual y in-creased with the concentration increasing; and lEC-6 cel s pretreated with 50, 100, 200 and 500 μg/ml EPS for 24 h and then stimulated by 10 μg/ml LPS for 1 and 4 h were analyzed by RT-PCR method, and it was found that the expression of TNF-α mRNA induced by LPS could be effectively inhibited by EPS, and the inhibition rate at 4 h was higher than that at 1 h. [Conclusion] EPS could play its role of protecting intestinal mucosa by inhibiting the secretion of TNF-α mRNA by cel s un-der the stimulation of LPS, and such inhibition effects of EPS had concentration dependency and time dependency.

[目的]研究紫锥菊多糖(EPS)在内毒素(LPS)损伤小肠上皮细胞(IEC-6)时对肿瘤坏死因子(TNF)表达的影响,以探讨EPS对损伤细胞的作用机制。[方法]采用TRIzon试剂提取总RNA,RT-PCR扩增TNF-αm RNA,琼脂糖凝胶电泳,并进行电泳及图像分析。[结果]50μg/ml EPS可以部分抑制LPS刺激IEC-6产生的TNF-αm RNA水平,而200、500μg/ml EPS随着浓度的增加,其抑制TNF-αm RNA的水平逐渐增加;将IEC-6分别用50、100、200及500μg/ml EPS预处理24 h,然后用10μg/ml LPS刺激达1、4 h,采用RT-PCR方法分析得,LPS诱导TNF-αm RNA表达被EPS有效地抑制,4h的抑制率高于1 h的抑制率。[结论]EPS通过抑制LPS刺激细胞分泌TNF-αm RNA的产生而起到肠道粘膜的保护作用,且EPS对这种抑制作用具有浓度及时间依赖性。