Cytotoxicity of CPA and CITCO in human primary hepatocytes. (A) HPHs from donors (HL#42 and HL#45) in 96-well collagen coated plate were treated with CPA at the wide range of concentrations in the presence and absence of CITCO (1μM). Prototypical MTT assays were performed 48 hours after the treatments as described in “Methods.” Cell viability data represent mean ± SD from 3 independent measurements and are expressed as percent of vehicle control. (B) Morphologic changes of HPHs in the coculture model were monitored under microscopy after various treatments. CPA at 4000μM was used as a positive control demonstrating toxic morphology damages to the HPHs.