OBJECTIVE:To determine the effects of Bushenhuoxue formula(BHF) on interleukin-1 beta(IL-1β),transforming growth factor beta 1(TGF-β1),discoidin domain receptor 2(DDR2) and matrix metalloproteinase-1(MMP-1) levels in a rat model of osteoarthritis(OA).METHODS:Sprague-Dawley rats were used to establish an OA model and subjected to various treatments over 6 weeks.Rats were treated with BHF,glucosamine sulfate(G5),or starch as a control.Serum levels of IL-1β and MMP-1 and joint fluid levels of IL-1 β were determined by means of ELISAs.We used immunohistochemistry to determine DDR2 levels in knee cartilage.Gene expression levels of MMP-1 in joint synovial tissue were assessed using reverse transcription polymerase chain reaction assays.RESULTS:Serum IL-1β levels were unchanged throughout the study.Levels of IL-1β in joint fluid and MMP-1 in sera from the BHF- and GS-treated groups were significantly reduced.DDR2 levels in knee cartilage were also significantly reduced in the BHF group.Expression of the MMP-1 gene was significantly reduced by BHF treatment.CONCLUSION:BHF might be beneficial in the inhibition and alleviation of local inflammatory responses and cartilage degeneration in OA.