Effects of Qing Hua Chang Yin on lipopolysaccharide­induced intestinal epithelial tight junction injury in Caco­2 cells.

Disruption of the intestinal mucosal barrier integrity is a pathogenic process in inflammatory bowel disease (IBD) development, and is therefore considered a drug discovery target for IBD. The well­known traditional Chinese formulation Qing Hua Chang Yin (QHCY) has been suggested as a potential therapeutic agent for the treatment of ulcerative colitis. However, the possible underlying molecular mechanisms regarding its therapeutic effect remain unclear. Consequently, the present study investigated the effects of QHCY on lipopolysaccharide (LPS)­induced loss of intestinal epithelial barrier integrity in vitro using the Caco­2 cell model of intestinal epithelium. QHCY reversed the LPS­induced decrease in transepithelial electrical resistance and significantly alleviated the increased fluorescently­labeled dextran 4 flux caused by LPS. Moreover, QHCY upregulated the mRNA and protein expression levels of occludin, zona occludens­1 and claudin­1 in LPS­exposed Caco­2 cells. In conclusion, QHCY was able to protect intestinal epithelial barrier integrity following an inflammatory insult; the protective effects of QHCY may be mediated by modulation of the expression of tight junction proteins.

Qing Hua Chang Yin inhibits the LPS-induced activation of the IL-6/STAT3 signaling pathway in human intestinal Caco-2 cells.

Increasing evidence indicates that the pathogenesis of ulcerative colitis (UC) is highly regulated by the interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) pathway and its negative feedback regulator, suppressor of cytokine signaling 3 (SOCS3). Therefore, modulating the signaling feedback loop of IL-6/STAT3/SOCS3 may prove to be a novel therapeutic approach for the treatment of UC. Qing Hua Chang Yin (QHCY) is a traditional Chinese formulation that has long been used in clinic for the treatment of UC. We have previously reported that QHCY ameliorates acute intestinal inflammation in vivo and in vitro through the suppression of the nuclear factor-κB (NF-κB) pathway. In the present study, in order to further elucidate the mechanisms responsible for the anti-inflammatory activities of QHCY, we stimulated human intestinal Caco-2 cells with lipopolysaccharide (LPS) to create an in vitro model of an inflamed human intestinal epithelium, and evaluated the effects of QHCY on the IL-6/STAT3/SOCS3 signaling network in inflamed Caco-2 cells. The levels of IL-6 were measured by ELISA and the levels of STAT3 and SOCS3 were measured by western blot analysis. We found that QHCY significantly inhibited the LPS-induced secretion of pro-inflammatory IL-6 in the Caco-2 cells in a dose-dependent manner. Moreover, QHCY profoundly suppressed the LPS-induced phosphorylation of Janus-activated kinase 1 (JAK1), JAK2 and STAT3. Furthermore, treatment with QHCY markedly augmented the expression of SOCS3. Taken together, the findings of the present study suggest that the modulation of the IL-6/STAT3/SOCS3 signaling network may be one of the mechanisms through which QHCY exerts its anti-inflammatory effects.

[Qinghuachang Decoction Inhibited NF-kappaB Activation in LPS-induced Human Enterocytes].

OBJECTIVE: To 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). METHODS: QD 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. RESULTS: Compared 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. CONCLUSION: QD inhibited LPS mediated NF-kappaB activation, which might be one of its mechanisms for treating inflammatory bowel disease (IBD).

Qing Hua Chang Yin exerts therapeutic effects against ulcerative colitis through the inhibition of the TLR4/NF-κB pathway.

The activation of the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway has been implicated as a key mediator in the pathogenesis of ulcerative colitis (UC); therefore, it has become an attractive target for the treatment of UC. Qing Hua Chang Yin (QHCY) is a traditional Chinese formula, which has been used for many years to clinically treat conditions associated with inflammatory bowel diseases, such as UC. However, the precise mechanisms behind its anti-inflammatory effects remain largely unknown. In this study, using the dextran sulfate sodium (DSS)-induced colitis mouse model, we evaluated the therapeutic effects of QHCY against UC and elucidated the possible underlying molecular mechanisms. We found that the administration of QHCY profoundly ameliorated DSS-induced clinical manifestations, colon shortening and histological damage in the mice with colitis. In addition, treatment with QHCY significantly decreased the DSS-induced secretion of serum amylase. Moreover, QHCY significantly inhibited the DSS-induced expression of TLR4 and myeloid differentiation primary response gene 88 (MyD88), the phosphorylation of IκB and the nuclear translocation of NF-κB. Taken together, our findings suggest that the suppression of the TLR4/NF-κB signaling pathway may be one of the mechanisms involved in the therapeutic effects of QHCY against UC.

Qing Hua Chang Yin attenuates lipopolysaccharide-induced inflammatory response in human intestinal cells by inhibiting NF-κB activation.

Ulcerative colitis (UC) is a major form of inflammatory bowel disease (IBD), which is tightly regulated by the nuclear factor κB (NF-κB) pathway. Thus, the suppression of NF-κB signaling may provide a promising strategy for the treatment of UC. Qing Hua Chang Yin (QHCY) is a traditional Chinese formulation, which has been used for a number of years to clinically treat UC. However, little is known with regard to its anti-inflammatory properties. In the present study, lipopolysaccharide (LPS)-stimulated Caco-2 cells were used as an in vitro inflammatory model of the human intestinal epithelium to evaluate the anti-inflammatory effects of QHCY and its underlying molecular mechanisms. We observed that QHCY inhibited the inflammatory response in intestinal epithelial cells as it significantly and concentration-dependently reduced the LPS-induced secretion of pro-inflammatory TNF-α and IL-8 in Caco-2 cells. Furthermore, QHCY treatment inhibited the phosphorylation of IκB and the nuclear translocation of NF-κB in Caco-2 cells in a concentration-dependent manner, indicating that QHCY suppressed the activation of the NF-κB signaling pathway. Collectively, our results suggest that the inhibition of NF-κB-mediated inflammation may constitute a potential mechanism by which QHCY treats UC.