Chondroprotective effects of pomegranate juice on monoiodoacetate-induced osteoarthritis of the knee joint of mice.

To study the effectiveness of pomegranate juice on osteoarthritis, mono-iodoacetate induced loss of articular cartilage in the mouse tibiofemoral joint was used as a model. Mono-iodoacetate is an inhibitor of glycolysis which promotes osteoarthritis similar to that noted in human osteoarthritis. The histopathology of the subchondral bone and cartilage of mouse knee joints treated with a single intra-articular injection of mono-iodoacetate (0.1 mg) and killed at 1, 14 and 28 days post injection was investigated. The effect of pomegranate juice (4 mL/kg, 10 mL/kg, 20 mL/kg, orally) was studied in different groups. Histopathological changes in knee joints were seen after 2 weeks. Early osteoarthritis was characterized by areas of chondrocyte degeneration, which sometimes involved the entire thickness of the articular cartilage in the tibial plateaus and femoral condyles. Changes to the subchondral bone and proteoglycan contents, focal fragmentation and collapse of bony trabeculae with fibrosis and necrosis, and synovial cell proliferation were observed. The administration of pomegranate juice dose dependently prevented the negative effects of iodoacetate. Chondrocyte damage was significantly prevented, with proteoglycan less affected, especially in the groups receiving a high amount of pomegranate juice. No cell proliferation or inflammatory cells were detected in the synovial fluid. The effectiveness of pomegranate juice in improving histopathological damage is emphasized and its chondroprotective effect in vivo highlighted.