1 × 105 LX2 cells, 1 × 105 HepG2 cells and 5 × 104 HSC-T6 cells were plated in 12 well-plates in complete culture medium and incubated for 24 h at 37°C. Cells were then treated with increasing doses (0.1, 1 and 10 μM) of NRB, NRB-AF12, glibenclamide and ER-Tr for 24 h. Cell viability was assessed by the Trypan Blue exclusion method. Briefly, cells were trypsinized, resuspended in complete medium, diluted 1:2 with a 0.4% Trypan Blue solution and finally counted using a hemacytometer under a light-microscope.