Abstract: Objective To observe the effect of Juncus effuses on osteoclasts differentiation from bone marrow macrophages (BMMs) induced by receptor activator for nuclear factor - κ B ligand (RANKL), and its mechanism thereof. Methods BMMs were isolated from whole bone marrow of 8-week-old C57/BL6 mice, and CCK-8 was used to detect the effect of Juncus on BMMs cell proliferation. Tartrate resistant acid phosphatase (TRAP) staining was used to show that 50 μg/L RANKL and 30 μg/L macrophage colony stimulating factor (M-CSF) stimulated the BMMs differentiation into osteoclasts, but the process was inhibited by Juncus (0, 6.25, 12.5 and 25 μmol / L). RT-PCR was used to detect the expressions of osteoclast-specific genes including calcitonin receptor (CTR), vacuolated H+ triphosphate transporter -d2 (V-ATPase-d2) and - a3 (V-ATPase-a3), activated T nuclear factor 1 (NFATC1) and C-FOS. Results There was no inhibition in the proliferation of BMMs cells treated with Juncus less than 12.5 mol/L detected by CCK-8. The 50 μg/L RANKL can induce BMMs differentiated into positive multinuclear giant cells detected by TRAP staining, but Juncus significantly inhibited osteoclast formation with a concentration dependence. The results of RT-PCR experiment showed that Juncus inhibited the expression of specific genes in osteoclast differentiation in concentration-dependent manner. Conclusion Juncus can inhibit osteoclast formation in concentration-dependent manner, resulting from the inhibitory effect on osteoclast specific gene expression.

Key words: Juncus effuses, osteoclasts, osteoporosis, RANKL, TRAP