Synergistic Effect of β-Cryptoxanthin and Zinc Sulfate on the Bone Component in Rat Femoral Tissues in Vitro: The Unique Anabolic Effect with Zinc

• Published in: Biological & pharmaceutical bulletin 2005, Vol.28(11), pp.2142-2145
• Main Authors: Uchiyama, Satoshi, Ishiyama, Kaori, Hashimoto, Ken, Yamaguchi, Masayoshi
• Format: Article
• Language: English
• Subjects: Alkaline Phosphatase - metabolism; Anabolic Agents - pharmacology; Animals; beta Carotene - analogs & derivatives; beta Carotene - pharmacology; Bone and Bones - drug effects; Bone and Bones - metabolism; bone formation; Calcium - metabolism; Cryptoxanthins; Cycloheximide - pharmacology; DNA - biosynthesis; Drug Synergism; Femur - drug effects; Femur - metabolism; Male; Protein Synthesis Inhibitors - pharmacology; rat femur; Rats; Rats, Wistar; Tissue Culture Techniques; Xanthophylls; zinc; Zinc Sulfate - pharmacology; β-cryptoxanthin
• ISSN: 0918-6158; 1347-5215
• DOI: 10.1248/bpb.28.2142

The effect of the combination of β-cryptoxanthin and zinc sulfate (zinc) on bone components in the femoral-diaphyseal and -metaphyseal tissues of young rats in vitro was investigated. Bone tissues were cultured for 48 h in a serum-free Dulbecco's modified Eagle's medium containing either vehicle, β-cryptoxanthin (10−9—10−7 M) or zinc sulfate (10−6—10−4 M). The presence of β-cryptoxanthin (10−9 M) or zinc (10−6 M) did not have a significant effect on calcium content in the femoral-diaphyseal or -metaphyseal tissues. However, culture which combined β-cryptoxanthin (10−9 M) and zinc (10−6 M) caused a significant increase in calcium content in the femoral-diaphyseal and -metaphyseal tissues. Such an effect was not observed by the combination of β-cryptoxanthin (10−9 M) plus genistein (10−6 M) or menaquinone-7 (10−6 M), or zinc (10−6 M) plus genistein (10−6 M) or menaquinone-7 (10−6 M). Also, the combination of β-cryptoxanthin (10−9 M) plus zinc (10−6 M) caused a remarkable increase in alkaline phosphatase activity and deoxyribonucleic acid (DNA) in the femoral-diaphyseal and -metaphyseal tissues, while their application alone did not have an effect on the enzyme activity or DNA content in the femoral tissues. The effect of the combination of β-cryptoxanthin (10−9 M) plus zinc (10−6 M) in increasing calcium content, alkaline phosphatase activity, and DNA content in the femoral-diaphyseal and -metaphyseal tissues was completely prevented in the presence of cycloheximide (10−6 M), an inhibitor of protein synthesis, or 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DBR), an inhibitor of transcriptional activity. This study demonstrates that the combination of β-cryptoxanthin and zinc at a lower concentration has a synergistic effect on bone components in vitro.