Fig. 2.

Resorption biomarkers released from osteoclasts cultured on cortical bone. Osteoclasts were cultured on bovine femoral cortical bone in the presence or absence of resorption inhibitors. Resorption of calcified extracellular matrix and collagen type I was assessed by measuring the Ca²⁺ (a) and C-terminal type I collagen (CTX-I) (b) concentrations, respectively, in the medium. Cell viability was assessed using alamarBlue (c) and tartrate-resistant acid phosphatase (TRAP) activity in the medium was measured for relative osteoclast quantification (d). Data are presented as percent of vehicle with error bars representing the SEM. Statistical significance is indicated by ^*p < 0.05, ^**p < 0.01, ^***p < 0.001, ^****p < 0.0001 for comparisons against the vehicle and ^#p < 0.05, ^##p < 0.01, ^###p < 0.001, ^####p < 0.0001 for comparisons against E-64/GM6001 (only shown for E-64 and GM6001); the post hoc test used is indicated in the top left corner of each graph