Chondroprotective effect of Alpinia oxyphylla extract in experimentally induced cartilage degradation in rabbit articular cartilage explants

Alpinia oxyphylla is a widely used medicinal herb for diarrhea, gastralgia, tumors, hypertention, and cerebrovascular disorders. Here, we evaluated the chondroprotective effect of A. oxyphylla dried fruit ethanol extract (AOE) against cartilage degradation in rabbit articular cartilage explants. Treatment of interleukin‐1α (IL‐1α) and plasminogen increased degraded collagen release in culture supernatants, but pretreatment of AOE (50, 100, 200 µg/ml) inhibited the collagen release in dose‐dependent manner. To examine the mechanism of action of AOE on chondroprotection, the level of matrix metalloproteinases‐3 (MMP‐3), matrix metalloproteinases‐13 (MMP‐13), tissue inhibitor of metalloprotease‐1 (TIMP‐1), and inflammatory mediators like prostaglandin E2 (PGE2) and nitric oxide (NO) was evaluated. AOE inhibited upregulation of MMP‐3 and MMP‐13 and downregulation of TIMP‐1 and also reduced increase of PGE2 and NO level induced by exposure of IL‐1α and plasminogen. These results indicate that AOE show chondroprotective effect through inhibiting collagen degradation via regulating MMPs, TIMP‐1, and inflammatory mediators. Practical applications Osteoarthritis (OA) is a one of the most common chronic disorders in elderly persons. Because the regenerative power of joint articular cartilage is very low, treatment of OA is difficult to expect complete recovery. Therefore, there is a need to develop a therapeutic agent that can safely and effectively inhibit the cartilage destruction. For the first time, we exhibited the inhibitory effect of AOE on collagen degradation through regulating MMPs and TIMP‐1 in articular cartilage explants. These findings support AOE could be used as herbal therapeutic application for protecting articular cartilage to prevent OA. In this study, we investigated the chondroprotective effect of Alpinia oxyphylla fructus ethanol extract (AOE) against cartilage degradation in rabbit articular cartilage explants. AOE inhibited collagen degradation through regulating matrix metalloproteinases, tissue inhibitor of matrix metalloprotease and inflammatory mediators.