Abstract: The purpose of this study was to observe the effect of Plumbago zeylanica analgesic spray (PZAS) on the morphological changes of articular cartilage and the expression of inflammatory cytokines and free radicals by using the New Zealand rabbit model of knee osteoarthritis,and to explore the effect of P.zeylanica and its new external method on osteoarthritis,and hence to provide the corresponding pharmacodynamic basis for clinical application.After the successful model of the knee cavity injection of papain,the rabbits were randomly divided into normal control group,model group,voltaren (diclofenac diethylamine) emulgel group, P.zeylanica spray group with high dosage (2 mg/mL),medium dosage (1 mg/mL) and low dosage (0.5 mg/mL).After 6 weeks of drug delivery,the content of serum TNF-α and IL-6 was determined by Elisa,and the articular synovial tissue homogenate was used as MDA (Malondialdehyde,TBA method) and increased SOD (Superoxide dismutase,Hydroxylamine method),the tibial plateau articular cartilage was prepared by paraffin section,and HE staining and toluidine blue staining were observed using Mankin’s standard.The results showed that the analgesic aerosol spray can effectively reduce the inflammatory factor TNF-α and IL-6 value (P<0.05) in the model of knee arthritis in New Zealand rabbits,effectively reduce the value of MDA and increased SOD value (P<0.05) in the synovial membrane;the mean arthritis index was effectively reduced (P<0.05);The high and medium dosage groups were better than the voltaren emulgel group in the cartilage structure,chondrocyte,toluidine blue staining and the integrity of the tidal line (P<0.01 or P<0.05).It is suggested that P.zeylanica analgesic spray can effectively inhibit the development of osteoarthritis,improve the pathological morphology of articular cartilage,and inhibit inflammatory factors,also can resist oxidation,and thus play a therapeutic role.

Key words: Plumbago zeylanica, osteoarthritis, cartilage pathology, inflammatory factors, anti-inflammatory