Fig. 2.

Metabolic activity of SAOS-2 cells 24 h after exposure to PP-50 at difference concentrations for either 2 or 24 h. These data were normalised to cells incubated in the absence of PP-50, at the same pH and incubation time, and were derived from three replicates. * and ** denote significant differences of p < 0.05 and p < 0.01, respectively from the no PP-50 controls.