ACP5 and rheumatoid arthritis: Figure 2B demonstrates that RANKL induced osteoclast differentiation, and SMEF could impair such differentiation in a dose-dependent manner. Furthermore, we investigated whether the extract was effective on RANKL-stimulated TRAP activity in RAW 264.7 cells. RA was used as a positive control. The negative control (CON) was a nontreated group and set as 100%. TRAP activity increased by up to 163.4 ± 14.2% after treatment with RANKL compared with that of the control. SMEF significantly decreased RANKL-induced TRAP activity, similar to the positive control, as illustrated in Figure 2C.