Fig. 1.

Metformin represses PB and CITCO induced CYP2B6 expression. Human hepatocytes (HL#73 and #74) were treated with vehicle control (CT; 0.1% DMSO), PB (1 mM), CITCO (1 µM), MET (0.1, 0.5, 1 mM), or their combinations as indicated for 24 hours or 72 hours for analysis of mRNA and protein expression, respectively. Total RNA extracted from hepatocytes was subjected to real-time PCR analysis of CYP2B6 expression (A). Homogenate proteins (20 µg) from each group were prepared for CYP2B6 and β-actin immunoblotting analysis (B). Data represent the mean ± S.D. of three independent transfections (**P < 0.01).