Oral Administration of Beta-cryptoxanthin Induces Anabolic Effects on Bone Components in the Femoral Tissues of Rats in Vivo

The effect of beta-cryptoxanthin on bone components in the femoral tissues of rats was investigated. Beta-cryptoxanthin was isolated from Satsuma mandarin (Citrus unshiu MARC.). Bone tissues were cultured for 48 h in serum-free Dulbecco's modified Eagle's medium containing either vehicle or beta-cryptoxanthin (10(-7) or 10(-6) M). The presence of beta-cryptoxanthin (10(-7) or 10(-6) M) caused a significant increase in calcium content and alkaline phosphatase activity in the femoral-diaphyseal and femoral-metaphyseal tissues. These increases were completely abolished in the presence of cycloheximide (10(-6) M), an inhibitor of protein synthesis. Thus beta-cryptoxanthin had an anabolic effect on bone calcification in vitro. Moreover, beta-cryptoxanthin (10, 25, or 50 microg/100 g body weight) was orally administered once daily for 7 d to young male rats. The administration of beta-cryptoxanthin (10, 25, or 50 microg/100 g body weight) caused a significant increase in calcium content and alkaline phosphatase activity in the femoral-diaphyseal and femoral-metaphyseal tissues. Femoral-diaphyseal and femoral-metaphyseal DNA contents were significantly increased by the dose of 25 or 50 microg/100 g body weight. A significant increase in metaphyseal DNA content was also seen with the dose of 10 microg/100 g body weight of beta-cryptoxanthin. This study demonstrates that beta-cryptoxanthin has an anabolic effect on bone components in rats in vitro and in vivo.