Enzyme activities of MMP-9 and cathepsin K were repressed by subsequent addition of (+)-vitisin A (Vt-A).

MMP-9 activities (A) were analyzed using gelatin zymographic assays and cathepsin K activity (B) was measured by using QFRET Technology as described in methods. Data represent the mean ± SEM of four independent experiments.*p<0.05, **p<0.01 and ***p< 0.001, different from values after stimulated with RANKL alone.