Pharmacokinetics and Tissue Distribution of Oleic and Linoleic Acids Following Oral and Rectal Administration of Brucea javanica Oil in Rats

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.

Activity of Brucea javanica oil emulsion against gastric ulcers in rodents

The present study aims to investigate the gastroprotective effect of Brucea javanica oil emulsion (BJOE) in animals. Gastroprotective potential of BJOE was studied on absolute ethanol, aspirin, reserpine and restraint plus water immersion-induced gastric ulcers in mice as well as glacial acetic acid (GAA) and pyloric ligation (PL)-induced gastric ulcers in rats. Except for ulcer scores, total acidity as well as pepsin activity as for the PL-induced gastric ulcer model and ulcer incidence as for the GAA-induced gastric ulcer model were also determined. Histopathological evaluation as for aspirin, reserpine, PL-induced models was conducted. Results showed that BJOE significantly (P < 0.05) reduced ulcer index in the mouse and rat models in a dose-dependent manner. It had significant (P < 0.05) suppressive effect on total activity of gastric juice as well in PL-induced model. Histopathological examination for the stomach samples confirmed the findings in the aspirin, reserpine or PL-induced gastric lesion models, which showed relatively complete mucosa structure and less inflammation. It is concluded that BJOE could be effective on gastric ulcer in rodents and its gastroprotective activity might be related to antioxidant, anti-inflammatory ability and promote gastric mucus secreted. The results may provide beneficial basis for increasing BJOE's clinical indication in future.

Anti-inflammatory effects of Brucea javanica oil emulsion by suppressing NF-κB activation on dextran sulfate sodium-induced ulcerative colitis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Brucea javanica is an important traditional medicinal herb used for the treatment of dysentery, malaria, inflammation and cancer in southeast Asia for many years. However, the anti-inflammatory mechanism of Brucea javanica in the treatment of dysentery (also known as ulcerative colitis, UC) has not been fully illuminated. Brucea javanica oil emulsion (BJOE) is the major active and most common application form of Brucea javanica oil (BJO), which has a variety of pharmacological activities. The aim of this study was to investigate the potential anti-inflammatory effect of BJOE and possible mechanism of action on dextran sulfate sodium (DSS)-induced UC in mice.

MATERIALS AND METHODS

The components of BJOE were determined by gas chromatography-mass spectrometry (GC-MS). Balb/C mice with dextran sulfate sodium (DSS, 30mg/mL) induced colitis were treated with BJOE (0.5, 1 and 2g/kg) and two positive drugs (sulfasalazine, SASP, 200mg/kg; and azathioprine, AZA, 13mg/kg) once daily by gavage for 7 days. Mice in normal control group and DSS group were orally given the same volume of distilled water and soybean lecithin suspension (0.15g/kg) respectively. The effects of BJOE on DSS-induced UC were assessed by determination of body weight loss, disease activity index (DAI), colon length, histological analysis, as well as levels of pro-inflammatory cytokines. The mRNA expression of MPO, iNOS and COX-2 in colon tissues was detected by qRT-PCR. In addition, NF-κB p65, p-p65 and IκB-α, p-IκBα protein expression levels in colon tissues were investigated using Western blotting.

RESULTS

The major components of BJOE were found to be oleic acid (62.68%) and linoleic acid (19.53%) as detected by GC-MS. Our results indicated that BJOE, SASP and AZA showed beneficial effect on DSS-induced colitis in mice, and significantly reduced the body weight loss and DAI, restored the colon length, repaired colonic pathological variations, decreased histological scores, and decreased the levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-17 and IFN-γ) as compared with the DSS group. In addition, the mRNA expression of MPO, iNOS and COX-2 induced by DSS treatment was remarkably inhibited by BJOE, SASP or AZA treatments. Furthermore, when compared with DSS-treated mice, the activation of NF-κB was significantly inhibited by AZA and BJOE treatment.

CONCLUSIONS

Our study shows that BJOE possessed appreciable anti-inflammatory effect against murine experimental UC induced by DSS. The protective mechanism of BJOE may involve inhibition of NF-κB signal transduction pathways and subsequent down-regulation of inflammatory mediators. These findings suggest that BJOE might be an efficacious and promising therapeutic approach for the treatment of UC. Our investigation might also provide experimental evidence for the traditional application of Brucea javanica in the treatment of dysentery and might add new dimension to the clinical indications for BJOE.