Oral administration of beta-cryptoxanthin prevents bone loss in ovariectomized rats.

The effect of beta-cryptoxanthin, a kind of carotenoid, on ovariectomy-induced bone loss was investigated. beta-cryptoxanthin was isolated from Satsuma mandarin (Citrus unshu. MARC). beta-cryptoxanthin (5 or 10 microg/100 g body weight) was orally administered once daily for 3 months to ovariectomized (OVX) rats. OVX induced a significant increase in body weight and a significant decrease in serum calcium and inorganic phosphorus concentrations as compared with those of sham-operated (control) rats. These alterations induced by OVX were significantly prevented by the administration of beta-cryptoxanthin (5 or 10 microg/100 g). The analysis using a peripheral quantitative computed tomography (pQCT) showed that OVX induced a significant decrease in mineral content and mineral density in the femoral-diaphyseal and -metaphyseal tissues and polar strength strain index in the metaphyseal tissues. These decreases were significantly prevented by the administration of beta-cryptoxanthin (5 or 10 microg/100 g). Moreover, OVX induced a significant decrease in calcium content and alkaline phosphatase activity in the femoral-diaphyseal and -metaphyseal tissues and deoxyribonucleic acid (DNA) content in the metaphyseal tissues. These decreases were significantly prevented by the administration of beta-cryptoxanthin (5 or 10 microg/100 g). This study demonstrates that beta-cryptoxanthin has a preventive effect on OVX-induced bone loss in vivo.