第12回チュニジア日本文化科学技術シンポジウム(2011/11/11〜13)に 参加しました。

以下はシンポジウムで発表した概要です。

Effects of Olive Polyphenols on Bone Loss

Hiromi HAGIWARA¹, Tadashi GOTO¹ and Keitaro HAGIWARA²

1 Department of Biomedical Engineering, Toin University of Yokohama. Yokohama, Kanagawa 225-8503, Japan,
2 Department of Biological Sciences, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8501, Japan
hagiwara(at)toin.ac.jp

Abstract: Polyphenols reportedly exert the physiological effects against diseases such as cancer, arteriosclerosis, hyperlipidaemia and osteoporosis. The present study was designed to evaluate the effects of oleuropein, hydroxytyrosol, tyrosol and apigenin, the major polyphenols in olives, on bone formation using cultured osteoblasts and osteoclasts, and on bone loss in ovariectomized mice. Oleuropein, hydroxytyrosol and tyrosol did not markedly affect the proliferation of osteoblastic MC3T3-E1 cells at concentrations up to 10 μM, but apigenin at 5 μΜ inhibited it. Oleuropein and hydroxytyrosol at 10 to 100 μM had no effect on the production of type I collagen and the activity of alkaline phosphatase in MC3T3-E1 cells, but stimulated the deposition of calcium in a dose-dependent manner. In contrast, apigenin at 10 μM inhibited those osteoblastic indices. Furthermore, oleuropein at 10 to 100 μM, hydroxytyrosol at 50 to 100 μM and apigenin at 5 to 10 μM inhibited the formation of multinucleated osteoclasts in a dose-dependent manner. We also revealed that hydroxytyrosol suppressed the bone loss of trabecular bone in femurs of ovariectomized mice. Our findings indicate that the olive polyphenols hydroxytyrosol may have critical effects on the formation and maintenance of bone, and can be used as effective remedies in the treatment of osteoporosis symptoms.
Key words: Bone formation, Osteoblast, Osteoclast, Olive Polyphenol, OVX Mice.