Unkeito (UKT), Kamishoyosan (KSS), Kamikihito (KKT), and Ninjinyoeito (NYT) decrease tartaric acid resistant phosphatase (TRAP)-positive cells at the different stages of osteoclast differentiation. (a) TRAP staining for osteoclasts on days 5 (Magnification: ×100); (b) number of TRAP-positive mononuclear osteoclasts (nuclei/cell = 1) and mature osteoclasts (nuclei/cell ≥ 3 or 10) on days 3 and 5 (n = 3); (c) the expression levels of osteoclast-related gene markers Trap, Dcstamp, Mmp9, and Ctsk normalized to that of Gapdh. Error bars represent ± standard error of the mean. * p < 0.05; ** p < 0.01; *** p < 0.005; **** p < 0.0001, versus the control groups.