Acetylsalicylic acid combined with diclofenac inhibits cartilage degradation in rabbit models of osteoarthritis.

The present study aimed to investigate the effect of different concentrations of acetylsalicylic acid combined with diclofenac on the articular cartilage of a rabbit model of osteoarthritis (OA). A total of 40 New Zealand white rabbits were divided into 5 groups. Group A was a sham-operated control group, which was treated with normal saline. Groups B-E were OA models and were treated with normal saline and acetylsalicylic acid combined with diclofenac at concentrations of 5, 10 and 20 mg/kg, respectively. A cartilage macroscopic examination and a pathological observation were performed to analyze the structure of the articular cartilage in all of the treated groups. The nitric oxide (NO) content and interleukin 1β (IL-1β) levels were detected by an enzyme-linked immunosorbent assay. In addition, the protein expression of matrix metalloproteinase 3 (MMP)-3 and MMP-13 were detected by western blot analysis. The mRNA expression of tissue inhibitor of metalloproteinases 1 (TIMP1) was detected by polymerase chain reaction (PCR). The results revealed that different concentrations of the drugs significantly reduced the scores of cartilago articularis, the NO and IL-1β levels and the protein expression of MMP-3 and MMP-13. Furthermore, PCR revealed that the mRNA expression of TIMP1 was significantly upregulated, and the effects increased with increasing drug concentration. Thus, the administration of different concentrations of acetylsalicylic acid combined with diclofenac demonstrates preventive or therapeutic effects against OA progression.