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

Abstract

The effect of β-cryptoxanthin on bone components in the femoral tissues of rats was investigated. β-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 β-cryptoxanthin (10⁻⁷ or 10⁻⁶ M). The presence of β-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 β-cryptoxanthin had an anabolic effect on bone calcificantion in vitro. Moreover, β-cryptoxanthin (10, 25, or 50 μg/100 g body weight) was orally administered once daily for 7 d to young male rats. The administration of β-cryptoxanthin (10, 25, or 50 μg/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 μg/100 g body weight. A significant increase in metaphyseal DNA content was also seen with the dose of 10 μg/100 g body weight of β-cryptoxanthin. This study demonstrates that β-cryptoxanthin has an anabolic effect on bone components in rats in vitro and in vivo.