Effects of vitamin K on osteoblastic bone formation and osteoclastic bone absorption / 药学实践杂志

ABSTRACT

Objective To compare the effects of vitamin K1 (VK1), vitamin K2 (MK4), vitamin K2 (MK7) and vitamin K3 (VK3) on bone formation and bone absorption. Methods Osteoblasts were isolated from calvaria of newborn rats and osteoclasts were induced by receptor activator of nuclear factor-κ B ligand (RANKL). ALP and TRAP activity were measured by diphenyl phosphate method. Osteoclast metabolic activity was measured by Celltiter kit. The inhibition of cathepsin K (CTSK) was measured by Z-FR-MCA fluorescent substrate and collagen substrate degradation. Results MK4 and MK7 at 0.1~1 μmol/L significantly increased the proliferation of osteoblasts (P<0.05) and at 1 μmol/L increased ALP activity and bone nodule formation area. VK3 inhibited bone nodule formation (P<0.05). VK1,VK3,MK4 and MK7 at 1 μmol/L had no effect on osteoclastic bone absorption. MK4 and MK7 significantly inhibited TRAP activity at 0.1~1 μmol/L (P<0.05), while VK1 and VK3 did not show the inhibitory effect. The inhibition of MK4 at 25 μmol/L on CTSK binding to Z-FR-MCA substrate activity is 58.9% and the inhibition of MK4 at 100 μmol/L on collagen degradation of CTSK activity is 73.2%. Conclusion Compared with VK1 and VK3, MK7 and MK4 significantly increase osteoblast activity and inhibit osteoclast bone absorption, MK4 inhibits osteoclast CTSK enzyme activity.