Amelioration of the Development of Osteoarthritis by Daily Intake of β-Cryptoxanthin.

β-Cryptoxanthin, which is primarily obtained from citrus fruits such as Satsuma mandarins, is a major carotenoid routinely found in human serum. Recently, we demonstrated that daily oral intake of β-cryptoxanthin prevented ovariectomy-induced bone loss and ameliorated neuropathic pain in mice. Although β-cryptoxanthin exerts preventive effects on various lifestyle-related diseases, there have been no studies on the effect of β-cryptoxanthin on the development of osteoarthritis, the most common degenerative joint disease, which frequently leads to loss of ability and stiffness in the elderly. Here we showed that daily oral administration of β-cryptoxanthin significantly prevented the development of osteoarthritis developed by surgically inducing knee joint instability in mice in vivo. Furthermore, in vitro experiments revealed that β-cryptoxanthin markedly inhibited the expression of inflammatory cytokines and enzymes critical for the degradation of the extracellular matrix in primary chondrocytes. Our results suggest that oral supplementation of β-cryptoxanthin would be beneficial for the maintenance of joint health and as prophylaxis against osteoarthritis.