The Action Mechanism Of Brucea Javanica Oil Emulsion In Treating Inflammatory Bowel Disease

Research background Brucea javanica(L.)Merr,a plant species of the family Simaroubaceae,the fruits are used in traditional folk medicine for treating various inflammatory disorders including dysentery,which is consistent with IBD nowadays on the clinical symptoms.Modern medicine for Brucea javanica was mainly focused on its anti-tumor effect,but neglected its traditional application for dysentery.Brucea javanica oil emulsion(BJOE)is a water-oil emulsion made from the emulsification of fatty oil(Brucea javanica oil,BJO)extracted from dry ripe fruits,which has a variety of pharmacological activities.Inflammatory bowel disease(IBD)is a chronic intestinal autoimmune disease that the etiology remains to be elucidated more clearly.Despite that,IBD has been widely considered as an autoimmune that involves the chaos of intestinal immune system with high hereditary susceptibility,as well as the ambalance of intestinal flora.In this study,the potential effect of them against IBD was investigated in the view of regulation effect on the balance of immune-inflammatory,for a better illumination of the etiology of IBD.Methods 1.Analysis of components in BJOE After treating with demulsification and methyl esterification,the composition and content of the fat-soluble constituents in BJOE were separated and identified by gas chromatography-mass spectrometry(GC-MS).2.The therapeutic effect of BJOE against DSS-induced IBD in mice Male Balb/C mice with dextran sulfate sodium(DSS,30 mg/m L)induced colitis were treated with BJOE(0.5,1.0 and 2.0 g/kg)and two positive drugs(sulfasalazine,SASP,200 mg/kg;and azathioprine,AZA,13 mg/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(0.15 g/kg)respectively.The effects of BJOE on DSS-induced UC were assessed by determination of body weight loss,disease activity index(DAI),colon length,histologicalanalysis,as well as levels of pro-inflammatory cytokines(TNF-?,IL-1?,IL-6,IL-8,IL-17 and IFN-?).The m RNA expression of i NOS and COX-2 incolon tissues was detected by q RT-PCR.In addition,NF-?B p65,p-p65 and I?B-?,p-I?B? protein expression levels in colon tissues were investigated using Western blotting.3.The therapeutic effect of BJOE against TNBS-induced IBD in rats Male SD rats with 2,4,6-Trinitrobenzenesulfonic acid(TNBS,25mg/kg)induced colitis by infra-rectal installation were treated with BJOE(0.35,0.70 and 1.40 g/kg)and two positive drugs(sulfasalazine,SASP,100 mg/kg;and azathioprine,AZA,9 mg/kg)once daily by gavage for 7 days.Rats in normal control group and TNBS group were orally given the same volume of distilled water and soybean lecithin suspension(0.15 g/kg)respectively.The effects of BJOE on TNBS-induced IBD were assessed by determination of body weight loss,disease activity index(DAI),colon length,macroscopic and histologic assessment of colons,as well as the level of MPO activity,inflammatory cytokines(TNF-?,IL-1?,IL-6,IL-17,IL-23,IFN-?,IL-4,IL-10,TGF-?).The m RNA expression of MMP-1 and MMP-3 in colon tissues was detected by q RT-PCR.In addition,TLR4,My D88,IRAK-1,TRAF6 and I?B? protein expression levels in colon tissues were investigated using Western blotting.Results 1.Analysis of components in BJOE The GC-MS showed that four fat soluble constituents were identified from BJOE,including: Hexadecanoic acid(C17H34O2,8.81%),9Z,12Z-Octadecadienoic acid(C19H34O2,19.53%),9-Octadecenoic acid(C19H38O2,62.68%),and Heptadecanoic acid(C18H36O2,6.54%).2.The therapeutic effect of BJOE against DSS-induced ulcerative colitis in mice Our results indicated that BJOE 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-?,IL-1?,IL-6,IL-8,IL-17 and IFN-?)as compared with the DSS group.In addition,the m RNA expression of i NOS and COX-2 induced by DSS treatment was remarkably inhibited by BJOE treatments.Furthermore,when compared with DSS-treated mice,the activation of NF-?B was significantly inhibited by BJOE treatment.3.The therapeutic effect of BJOE against TNBS-induced IBD in rats Our results indicated that BJOE showed beneficial effect on TNBS-induced colitis in rats,and significantly reduced the body weight loss and DAI,restored the colon length,repaired colonic pathological variations,decreased histological scores and microscopic score,down-regulated the MPO activity,decreased the levels of pro-inflammatory cytokines(TNF-?,IL-1?,IL-6,IL-17,IL-23 and IFN-?)and up-regulation the activities of IL-4,IL-10 and TGF-?,as compared with the TNBS group.In addition,the m RNA expression of MMP-1 and MMP-3 and the activation of TLR4/My D88 related path induced by TNBS treatment was remarkably inhibited by BJOE treatments.Conclusions In summary,BJOE was proved to be effective in IBD,in which BJOE could improve the life quality of the suffering animals,and ameliorate the inflammation as indicated by less edema,ulcer,nerosis and leukocyte infiltration,thereby promoting mucosa healing.It is reasonable to infer that the IBD alleviation by BJOE would be related to its inhibitory effect on TLR4/My D88/NF-?B pathway as showed in the in vitro study.These findings suggest that BJOE might be an efficacious and promising therapeutic approach for the treatment of IBD.Our investigation might also provide experimental evidence for the traditional application of Brucea javanica in the treatment of dysentery and might add new ideas and methods to the clinical indications for BJOE.