Therapeutic effect of Brucea javanica oil emulsion on experimental Crohn's disease in rats: Involvement of TLR4/ NF-κB signaling pathway

Brucea javanica is an important Chinese folk medicine traditionally used for the treatment of dysentery (also known as inflammatory bowel diseases). Brucea javanica oil emulsion (BJOE), the most common preparation of Brucea javanica, has a variety of pharmacological activities. In this follow-up investigation, we endeavored to illuminate the potential benefit of BJOE on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-induced Crohn’s disease (CD) in rats and decipher the mechanism of action. The result illustrated that BJOE treatment significantly reduced the body weight loss, disease activity index and macroscopic scores, ameliorated shortening of colon length, arrested colonic histopathological deteriorations, lowered the histological scores in parallel to the model group. Furthermore, BJOE also decreased the levels of MPO and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-17, IL-23 and IFN-γ), and increased the levels of anti-inflammatory cytokines (IL-4, IL-10 and TGF-β) as compared with the model group. In addition, the elevated mRNA expression of MMP-1, MMP-3 and RAGE induced by TNBS was remarkably inhibited by BJOE, SASP or AZA treatments, while the mRNA expression of PPAR-γ was significantly enhanced. Furthermore, the activation of TLR4/NF-κB signaling pathway was significantly inhibited by AZA and BJOE treatment when compared with that of TNBS-treated rats. Our study suggested that BJOE exerted superior therapeutic effect to SASP and AZA in treating TNBS-induced colitis in rats. The protective effect of BJOE may involve the inhibition of the TLR4/NF-κB-mediated inflammatory responses. These results indicated that BJOE held promising potential to be further developed into a novel candidate for the treatment of CD.