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.
