Figure 1.

Effects of IL‐6 and INF‐α2a on CYP1A2, CYP2B6, and CYP3A4 mRNA expression and enzyme activity in culture of primary human hepatocytes. Hepatocyte‐Kupffer cell cocultures (N = 3, experiment in cells from each donor was conducted once) were incubated for 72 hour with medium alone, medium containing phenobarbital (750 µmol/L), IL‐6 (2, 10 or 50 ng/mL), or INF‐α2a (0.1, 0.5 or 2.5 ng/mL). The mRNA levels of each P450 were quantitated by qPCR with normalization to glyceraldehyde 3‐phosphate dehydrogenase mRNA and to the mRNA levels of the P450 in the medium control cultures. The enzymatic activity of the P450 enzymes were determined as described in Materials and Methods. Data were normalized to medium control cultures values set to equal 1. Patterned bars indicate observations of mRNA or enzyme activity levels below 50% of the control or observations of enzyme activity above 2‐fold of the control. Asterisk (*) indicates difference from the control with one‐tailed t test, P < .05 (SigmaPlot™ 12.5, Systat Software, Inc)