IL1B and Arthritis: For these reasons, the present study used healthy equine cartilage explants cultured in serum-free media, either alone (representing healthy cartilage), in the presence of the pro-inflammatory cytokine equine IL-1β (equine recombinant protein) to replicate the early inflammatory stages of OA, or a combination of IL-1β and carprofen (a COX-2 specific non-steroidal anti-inflammatory drug (NSAID) commonly used to treat arthritic symptoms and joint inflammation) to simulate anti-inflammatory pharmacotherapy.