Abstrakt

Vitamin K2 analog menaquinone-7 shows osteoblastic bone formation activity in vitro

Min Zhu, Jinxing Ma, Sheng Lu, Yueliang Zhu, Yi Cui, Hongbo Tan, Jiang Wu, Yongqing Xu

An increasing number of studies have shown that vitamin K may play a critical role in metabolism of bone. However, the anabolic effect of MK-7 on promoting bone formation needs to be further investigated. The present study investigates the effect of MK-7 on osteoblastic bone formation in femoral-diaphyseal and -metaphyseal tissues of 4-week-old rats (n=18). The rat tissue was cultured in Dulbecco’s modified Eagle’s medium supplemented with MK-7 (10^-6M). The activity of alkaline phosphatase DNA content, and calcium content in diaphyseal and metaphyseal tissues were used as osteogenesis markers. The study showed that treatment with MK-7 significantly increased alkaline phosphatase activity, DNA content, and calcium content in the cultured diaphyseal and metaphyseal tissue; however, the activity was inhibited in the presence of epoxomicin (10^-6 M). Culture of human osteoblastic cells SAOS-2 for 24 h in a serum-free medium containing MK-7 (10^-6M) resulted in increased alkaline phosphatase activity, osteocalcin content, and DNA content, and the reaction was completely inhibited in presence of by epoxomicin. The study results indicate that MK-7 has a stimulatory effect on bone tissue and osteoblastic SAOS-2 cells in vitro and further clinical studies are required to pave way for the use of MK-7 in bone formation.