HepG2 cells: an in vitro model for P450-dependent metabolism of acetaminophen.

The human hepatoma cell line, HepG2, retains many cellular functions often lost by cells in culture. This research examined the constitutive bioactivation of acetaminophen and P450-dependent activity in microsomes from HepG2 cells and the effect of 0.1% acetone pretreatment on these activities. Low levels of acetaminophen bioactivation, P450 IIE1 activity, and P450 IA1-IA2 activity were demonstrated in non-induced HepG2 microsomes. Acetone increased acetaminophen bioactivation and IIE1-dependent metabolism but not P450 IA1-IA2-dependent activity. Thus, HepG2 cells may provide an in vitro model for assessing human xenobiotic metabolism of acetaminophen and other drugs.