AIM:To investigate the effect of ash bark(orally taken instant granules) on nitric oxide(NO),prostaglandin E2(PGE2) of
synovial fluid and matrix metalloproteinase 1(MMP 1) in
cartilage in the model of experimental osteoarthritis(OA),and determine the effect of ash bark in repair of OA. METHODS:The experiment was conducted in the Laboratory for Animals,Renmin Hospital of Wuhan University form March to May 2004.Eighteen flap eared Japanese white rabbits were randomly divided into sham
operation group,control group and treatment group.OA was induced in 12 rabbits by anterior cruciate ligament transection(ACLT) to establish model of OA.And,other 6 rabbits(sham operation group) received unilateral knee arthrotomy as sham operation controls.Stomachs of treatment group were perfused with ash bark 200 mg/kg per day after operation.Control group and sham operation group were given normal saline.All rabbits were killed at 8 weeks post surgery,synovial fluid was collected,and NO,PGE2 were examined.The expression of MMP 1 of cartilage was detected by immunohistochemistry.Samples of joint were collected for gross and light microscopic observation.The data were managed with paired t test by SPSS 10.0. RESULTS:Cartilage degeneration in treatment group was significantly slighter than that in control group,and the levels of MMP 1,NO,PGE2 in treatment group was significantly lower than those in control group(t=3.1,t=3.7,t=3.2,P< 0.05). CONCLUSION:Ash bark can significantly reduce the levels of MMP 1 in cartilage and NO,PGE2 in synovial fluid,and postpone the episode of OA.