Figure 3.

Inhibitory effect of rosmarinic acid and arbutin on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclasts from murine macrophage/osteoclast precursor cell line RAW 264.7 cells (RAW cells). RAW cells were treated with RANKL and rosmarinic acid or arbutin at the indicated concentrations. After 6 days in culture, the cells were fixed and stained for tartrate-resistant acid phosphatase (TRAP). (A and B) TRAP-positive multinucleated osteoclasts and TRAP-positive large multinucleated osteoclasts were counted under a microscope. (C and D) TRAP-positive osteoclasts were visualized by light microphotography. Data are representative of results from three separate experiments. Data are expressed as percentages of the value of the control cells (mean ± standard deviation, n=5). (**P<0.01 vs. control).