| Rheumatoid arthritis (rheumatoid arthritis, RA) is an unknown etiology, mainly to joint destruction in chronic disabling autoimmune disease. RA is the nature of chronic synovitis leading to joint cartilage / bone destruction, joint destruction is the main reason for disability RA. The pathological basis of RA synovitis, which sublining inflammatory cell infiltration is an important pathological changes. During the systemic inflammatory response process,macrophage is activated,which produces many inflammatory mediators,such as tumor necrosis factor alpha(TNF-α),inter- leukin-1(IL-1),interleukin-6(IL-6),matrix metalloproteinases (MMPs). The signal transduction pathways mediated by Tol1-1ike receptor 4(TLR4)is important in the inflammatory autoimmune disease,which mainly expressed on the surface of immune cells except to T, B cells and NK cell. Abnormal function changes of periloneal maerophage(PMΦ) from rats of adjuvant-induced arthritis(AA)may have some relation to the change of the TLR4 signal transduction pathways.The present study was designed to investigate the effects of oxymatrine (OM) in AA rats, the abnormal function changes of PMΦfrom AA rats and its relative mech- anisms on the signal transduetion of TLR4 of PMΦ.Thus,this study would provide theoretical basis for the better exploitation and utilization of traditional Chinese medicine.OBJECTIVEIn this study,we investigated the effects of OM on AA rats and abnormal function changes of PMΦfrom rats AA.We also investigated some mechanisms of OM on AA. METHODSFreund's complete adjuvant was used to induce AA in rats.Rats were divided into six groups,in which the rats with AA were given intragastrically OM(30,60,120 mg·kg-1·day-1) and glucosides of tripterygium wifordii(TPT)(30 mg·kg-1·day-1) from day 12 to 23 after immunization.And for the groups of normal and AA model,rats were given an equal volume of vehicle.Noninjected hind paw volumes of rats were measured by volume meter, arthritis index(AI), weight change determined the effect of OM on AA in rats, HE staining show the pathological changes in joints of rats, radioimmunoassay(RIA) measured serum IL-1β, TNF-αlevels. In vitro stimulation with different concentrations of OM on PMΦ,the IL-1βactivity and TNF-αactivity in PMΦsupernatant in AA rats were measured by ELISA test.The production of TLR4 in PMΦwere detected by Western blot analysis.RESULTS1.OM had therapeutic effects on AA ratsThe AA model in rats was induced by FCA.There was a marked secondary inflammatory response in this model similar characteristics to RA,which accompanied with paw swelling,polyarthritis,decrease of body weight and the development of inflammatory lesions.Therapeutic treatment of OM(60,120mg·kg-1,d12～23,ig) suppressed significantly the secondary paw swelling,improved arthritis inflammatory symptoms, deseased serum IL-1β, TNF-αlevel, indicating that OM may regulate AA rats abnormal immune system and reduce the release of inflammatory mediators.This suggested that OM might be effective on chronic autoimmune disease such as RA.2. Effects of OM may be related to inhibited abnormal activity of PMΦfrom AA ratsThe concentration of IL-1β, TNF-αhigher significantly from PMΦof AA rats than the normal rats.Therc was no influence in the level of IL-1βand TNF-αat the dose of OM(1.0×10-8,1.0×10-7mol·L-1) by vitro administration. OM(1.0×10-6,1.0×10-5,1.0×10-4 mol·L-1) decreased IL-1β,TNF-αactivity of PMΦsignificantly, which was demonstrated that the treatment of OM on rat AA through modulating immune functions.It also suggested that OM may regulate PMΦin AA by acting directly and via involvement in the effects of inflammatory cytokines.3. Effects of OM may be related to the signal transduction pathway of TLR4,NF-κB on PMΦ The further aim of this study was to examine association between TLR4 and NF-κB expression in PMΦafter stimulation with OM(1.0×10-6,1.0×10-5,1.0×10-4 mol·L-1).The study showed OM (1.0×10-5,1.0×10-4 mol·L-1) decreased the expression of TLR4 of PMΦ.It indicated that signaling mediated by TLR4 critical roles in the inflammation in AA.The effects of OM decreasing TLR4 level of PMΦmight be related to its inhibiting NF-κB.It was therefore likely that the therapeutic effects of OM on AA rats dued to the TLR4,NF-κB signal transduction of PMΦ.CONCLUSlONS1.OM had therapeutic effects on paw swelling in rats with AA.2.OM had inhibitory effects on the reduction of IL-1β,TNF-αfrom PMΦ.3.OM decreased the expression of TLR4,NF-κB of PMΦ.Regulation of the TLR4,NF-κB signal transduction pathway of PMΦmight be one of the important mechanisms by which OM exert the effects on rat AA. |
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