Physiologically based pharmacokinetic modeling for confirming the role of CYP3A1/2 and P‐glycoprotein in detoxification mechanism between glycyrrhizic acid and aconitine in rats

of AC towards CYP3A1/2 were 2.38 μM and 57.3 pmol/min/mg, respectively, whereas that of AC towards P-gp was 11.26 μM and 147.1 pmol/min/mg, respectively. GL markedly induced the mRNA expressions of CYP3A1/2 and MDR1a/b in rat primary hepatocytes. In vivo studies suggested that the intragastric and intravenous administration of GL significantly reduced systemic exposure of AC by 27% and 33%, respectively. Drug-drug interaction (DDI) model of PBPK predicted that co-administration of GL would decrease the exposure of AC by 39% and 45% in intragastric and intravenous dosing group, respectively. The consistency between predicted data and observed data confirmed that the upregulation of CYP3A1/2 and P-gp was the crucial detoxification mechanism between AC and GL. Thus, this study provides a demonstration for elucidating the compatibility mechanisms of herbal formula using PBPK modeling and gives support for the clinical co-medication of Fuzi and Gancao.