Effect of Nabumetone, Diclofenac, Ibuprofen and an Anti-Inflammatory Corticosteroid, Dexamethasone, on Cartilage Metabolism in a Biochemically-Induced Model of Osteoarthritis

The metabolism of articular cartilage, and the effects of 3 nonsteroidal antiinflammatory drugs (nabumetone, diclofenac and ibuprofen) and an antiinflammatory steroid (dexamethasone) were studied using a biochemically-induced model of osteoarthritis in the rat. Intra-articular injections of iodoacetate produced a transient inflammation and induced marked degenerative changes to the articular cartilage of the treated joint. All drug treatments reduced the iodoacetate-induced changes in damage score, tissue wet weight, cartilage metabolism and cartilage morphology. Dexamethasone also suppressed cartilage metabolism in the control joints. Levels of plasma haptoglobin were elevated in the dexamethasone-, ibuprofen- and diclofenac-treated but not in the nabumetonetreated animals. From these results in the rat, nabumetone appears to effectively reduce disease parameters in a model of osteoarthritis while not impairing normal cartilage metabolism.