Benoxaprofen reduces osteophyte formation and fibrillation after articular cartilage injury.

We examined the in vivo effect of benoxaprofen on the degeneration of articular cartilage after injection of sodium iodoacetate into the guinea pig knee. As shown previously, 3 weeks after the injection, samples from the ipsilateral knee of animals that did not receive benoxaprofen invariably exhibited marked loss of chondrocytes, absence of staining with safranin-O, fibrillation, and prominent osteophytes. In contrast, in samples from animals which received daily benoxaprofen (25 mg/kg) orally after the intraarticular injection of iodoacetate, pericellular safranin-O staining persisted, cell loss was less marked, osteophyte formation was markedly diminished and fibrillation occurred in only one of 5 samples. Knee cartilage from 2 animals that received benoxaprofen but were not injected with iodoacetate exhibited focal fibrillation, which may have been unrelated to the drug. Thus, benoxaprofen exhibited a marked protective effect in this chemically induced model of cartilage injury.