2022 Volume 18 Pages 28-33
Beta-cryptoxanthin is a typical carotenoid as the natural compound derived from citrus. Beta-cryptoxanthin possesses various biological activities including anti-oxidative effects, however, the effects of beta-cryptoxanthin on bone metabolism was still unclear. We reported that beta-cryptoxanthin showed bone protective effects through the inhibition of bone-resorbing cells such as osteoclasts. Beta-cryptoxanthin inhibited osteoclast differentiation and bone resorption that was induced by lipopolysaccharide (LPS), a major pathogenic factor of periodontitis. In osteoblasts, beta-cryptoxanthin suppressed mPGES (membrane-bound PGE synthase)-1 expression that was resulted in down-regulation of PGE2 production and following RANKL (receptor activator of NF-κB ligand) expression. In osteoclasts, beta-cryptoxanthin inhibited RANKL-induced osteoclast differentiation and induced apoptosis of mature osteoclasts. We further demonstrated that beta-cryptoxanthin directly suppressed IKK (inhibitor of NF-κB kinase) activity by competing for ATP in vitro assay. In silico molecular docking analysis showed that beta-cryptoxanthin binds to the ATP binding pocket of IKK protein. These data suggest that beta-cryptoxanthin blocks IKKNF-κB signaling via the direct suppression of IKK activity, followed by inhibiting PGE2-mediated osteoclast differentiation and function. In this review, we described the function of beta-cryptoxanthin on bone-related diseases. In conclusion, beta-cryptoxanthin is a candidate for a functional food for maintaining bone health in an aging society.
