OBJECTIVETo explore anti-inflammation and mechanism of Qinghuachang Decoction (QD) by using LPS stimulated differentiated colon cancer Caco-2 cells (as an inflammation model of human enterocytes).

METHODSQD was prepared. Human colonic epithelial Caco-2 cells were cultured. Expressions of TNF-alpha and IL-8 were determined using ELISA. Expressions of inhibitory Kaba protein (IkappaB-alpha), phosphorylated inhibitory Kaba protein (p-lkappaB-alpha), nuclear transcription factor p50 (p50), and nuclear transcription factor ReIA (ReIA) protein were determined by Western blot.

RESULTSCompared with the negative control group (without LPS stimulation), LPS stimulated the release of IL-8 and TNF-alpha in Caco-2 cells (P < 0.05). QD treatment could reduce the secretion of TNF-alpha and IL-8 induced by LPS in a dose dependent manner (P < 0.05). QD at 0, 5, 10, and 50 microg/mL had no significant effect on Caco-2 cell survival rates (P > 0.05), with no statistical difference among various concentrations (P > 0.05). QD could significantly suppress nuclear factor-kappa B (NF-kappaB) phosphorylation stimulated by LPS. The expression of p-IKappaB-alpha was decreased with increasing concentrations of QD (P < 0.05). There was no obvious change in IKB-alphaB expressions (P > 0.05). Expressions of p50 and ReIA decreased with increasing concentrations of QD (P < 0.05). Both of them were in a dose dependent manner.

CONCLUSIONQD inhibited LPS mediated NF-kappaB activation, which might be one of its mechanisms for treating inflammatory bowel disease (IBD).