OBJECTIVE

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To study the protective effect and mechanism of Shiyifang medicinal wine （SYF） on knee osteoarthritis （KOA） of rabbit induced by papain.

METHODS

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Thirty-five rabbits were randomly divided into blank group， model group， positive group （Diclofenac diethylamine emulsion 200 mg/kg）， SYF high-dose group （386 mg/kg） and SYF low-dose group （97 mg/kg）， with 7 rabbits in each group （all had 4 males and 3 females）. Except for the blank group， the other groups’ rabbits were injected 0.5 mL papain mixture （containing 2% papain and 0.03 mol/L L-cysteine） into the right knee cavity on day 1， 4 and 7， to replicate KOA model. Blank group was given constant volume of normal saline. From the 15th day， drugs were applied to right hind knee joints of rabbits in each group， twice a day for 20 days. At the same time， the diameter of right knee joints of rabbits was measured by vernier calipers at day 0， 8， 14 and 35 to calculate swelling degree. After the experiment， the levels of IL-1β， TNF-α and PGE

2

in synovial tissue were determined by enzyme-linked immunosorbent assay. Hematoxylin-eosin （HE） staining was used to prepare the sections of synovial tissue， and the pathological changes were observed. The relative mRNA expressions of TLR4， MyD88 and NF-кB p65 in the TLR4/MyD88/NF-кB signaling pathway were detected by real-time quantitative polymerase chain reaction.The relative protein expressions of TLR4， MyD88， NF-кB p65 and p-NF-кB p65 were detect by Western blot.

RESULTS

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Compared with blank group， the degree of knee swelling could be increased in model group， the pathological damage of synovial tissue was more serious， and the levels of IL-1β， TNF-α and PGE

2

were increased significantly in synovial tissue （

P

＜0.05）. The relative expression levels of TLR4， MyD88， NF-кB p65 mRNAs and TLR4， MyD88， p-NF-кB p65 proteins were significantly increased （

P

＜0.05）. Compared with model group， swelling degree of right hind knee and the pathological injury degree of synovial tissue were significantly improved in each treatment group， while the levels of IL-1β， TNF-α and PGE

2

in synovial tissue were significantly decreased （

P

＜0.05）. The relative mRNA expressions of TLR4， MyD88 and NF-кB p65 and relative protein expressions of TLR4， MyD88 （except for SYF low-dose group）and p-NF-кB p65 were all significantly decreased （

P

＜0.05）.

CONCLUSIONS

2

SYF shows protective effect on KOA induced by papain， the mechanism of which is associated with decreasing the levels of IL-1β， TNF-α and PGE

2

and down-regulating TLR4/MyD88/NF-кB signaling pathway.