Anti-inflammation of Tripterygium wilfordii Polycoride on Macrophages and Its Regulation to Inflammation via TLR4/NF-κB

Objective To investigate the inhibitory effect of Tripterygium wilfordii polycoride（TWP） towards the pro-inflammatory factors（TNF-α and IL-1β） on the inflammatory reaction in macrophages induced by LPS and its regulatory effect and influence on the inflammation via TLR4/NF-k B. Methods The MTT method was adopted to test the effect of drugs, TWP, dexamethasone（DXM） and azathioprine（AZA） on cell growth and to select the appropriate concentration. LPS was used to induce the inflammatory reaction in RAW264.7 cell line of mice. Elisa kit was adopted to test the levels of TNF-α and IL-1β. Western blotting was adopted to test the protein expression of TNF-α and IL-1β. RT-PCR was adopted to test the expression of TLR4 and NF-κB. Results The inhibiting effect of TWP on the release of TNF-α and IL-1β in a dose dependent manner. The inhibitory effect of three different TWP dose groups is weaker than that in DXM group. However, TWP in high dose is better than AZA on TNF-α and is as strong as AZA on IL-1β. The dose dependent manner also exits in the effect on the expression of TLR4 and NF-κB, the effect is not weaker, but even stronger than that of DXM and AZA. Conclusion The research shows that down regulation of TLR4 and NF-k B p65 may be one of the mechanisms about the TWP inhibitory effect on TNF-α and IL-1β.

Amelioration of Tripterygium wilfordii Polycoride on TNBS/Ethanol-induced Ulcerative Colitis via Inhibiting Lipid Peroxidation and Its Downstream Inflammatory Meditors

Objective To study the protective effect of Tripterygium wilfordii polycoride（TWP） against TNBS/ethanol-induced ulcerative colitis（UC） rat model. Methods TNBS and ethanol enema were adopted to build TNBS/ethanol-induced UC rat model. Ninety male Wistar rats were divided into six groups： normal, model, low-, medium-, high-dose TWP and azathioprine（AZA） groups, each for 15 rats. All rats were administered by corresponding medicine for 14 d. After 14 d, corresponding colon tissues underwent general and microscopic evaluation. Blood samples were taken from heart and serum was separated by centrifugation. MDA, SOD, GSH, IL-1β and TNF-α levels in serum were tested by ELISA. Colonic samples underwent RT-PCR and Western blotting analysis. Results DAI, general and microscopic evaluation all showed that TWP could promote colonic mucosa healing and such effect was equal to AZA. ELISA results about lipid peroxidation indicated that TWP could decrease MDA level and increase SOD and GSH levels in a dose-dependent manner. TWP with high dose could strongly decrease the MDA level and increase the SOD and GSH levels（P 〈 0.01）. ELISA results about inflammatory cytokines indicated that TWP could inhibit the expression of IL-1β and TNF-α in a dose-dependent manner. Western blotting analysis and RT-PCR all indicated that no matter in mR NA level or protein level, TWP could inhibit the expression of NF-κB, TNF-α, IL-1β, and IFN-γ in a dose-dependent manner. The inhibitory effect of AZA towards NF-κB was slightly weaker than TWP with high dose（P 〉 0.05）, whereas slightly stronger towards terminal inflammatory cytokines（P 〉 0.05）. Conclusion TWP could significantly lower the infiltration of inflammatory cells under microscope, eventually led to mucosa healing, the mechanism of which was to inhibit lipid peroxidation, then further inhibit NF-κB activation, eventually lower the expression of inflammatory meditors locally and systemically.