Figure 5.

Expression of mRNA for the master regulator of osteoclastogenesis, nuclear factor of activated T cells cytoplasmic 1 (NFATc1) and the osteoclast-specific marker genes, matrix metalloproteinase-9 (MMP-9), tartrate-resistant acid phosphatase (TRAP) and cathepsin-K, by quantitative polymerase chain reaction (qPCR). Murine macrophage/osteoclast precursor cell line RAW 264.7 cells were seeded in a 6-well plate at a density of 6×10⁴ cells/well and treated with receptor activator of nuclear factor-κB ligand and rosmarinic acid or arbutin at the indicated concentration for 24 h. (A and B) NFATc1, (C and D) MMP-9, (E and F) TRAP and (G and H) cathepsin-K expression was analyzed by qPCR as described in the Materials and methods. Results are shown as fold-change or relative quantitation of target expression (2^−ΔΔCt method) relative to the control following normalization against GAPDH expression. Data are representative of results from four separate experiments. Data are expressed as percentages of the value of the control cells (mean ± standard deviation, n=5). (**P<0.01 vs. control).