Fig. 3

Bile acid-induced apoptosis involves caspase activity that is reduced by a caspase inhibitor. NP69 and TWO4 cells were left untreated or pretreated with 50 μM of Z-DEVD-FMK (Caspase-3 Inhibitor II) for 1 h. Subsequently, NP69 cells were treated with 0.5 mM of BA at pH 7.4 and pH 5.8 for 1 h, whereas TWO4 were treated with 0.5 mM of BA at pH 7.4 and pH 5.8 for 3 h. The activity of caspase-3/7 was measured by using Caspase-Glo 3/7 Assay in (a) NP69 and (b) TWO4 cells. Means and SD of two independent experiments performed in duplicate are shown. Values were normalised to the percentage of untreated control. The differences between the untreated control and treated groups were compared by using Student’s t-test. An asterisk indicates a significant increase in BA-treated cells as compared with the untreated control, * p < 0.05, ** p < 0.01. An open diamond indicates a significant decrease in the sample with CI pretreatment as compared with its corresponding sample without CI pretreatment, ◊ p < 0.05, ◊◊ p < 0.01