Skip to main content

Research Repository

Advanced Search

Through a glass, darkly? HepaRG and HepG2 cells as models of human Phase I drug metabolism

Stanley, Lesley A.; Wolf, C. Roland


Lesley A. Stanley

C. Roland Wolf


The pharmacokinetic and safety assessment of drug candidates is becoming increasingly dependent upon in vitro models of hepatic metabolism and toxicity. Predominant among these is the HepG2 cell line, although HepaRG is becoming increasingly popular because of its perceived closer resemblance to human hepatocytes. We review the functionality of these cell lines in terms of Phase I protein expression, basal cytochrome P450-dependent activity and utility in P450 induction studies. Our analysis indicates that HepG2s are severely compromised: proteomic studies show that they express few key proteins in common with hepatocytes and they lack drug metabolizing capacity. Differentiated HepaRGs are more hepatocyte-like than HepG2s, but they also have limitations, and it is difficult to draw conclusions regarding their utility because of the enormous variability in data reported, possibly arising from the complex differentiation protocols required to obtain hepatocyte like cells. This is exacerbated by the use of DMSO in the induction protocol, together with proprietary supplements whose composition is a commercial secret. We conclude that, while currently available data on the utility of HepaRG generates a confusing picture, this line does have potential utility in drug metabolism studies. However, to allow studies to be compared directly a standardized, reproducible differentiation protocol is essential and the cell line’s functionality in terms of known mechanisms of P450 regulation must be demonstrated. We therefore support the development of regulatory guidelines for the use of HepaRGs in induction studies as a first step in generating a database of consistent, reliable data.

Journal Article Type Review
Acceptance Date Feb 5, 2022
Online Publication Date Feb 21, 2022
Publication Date 2022
Deposit Date Feb 22, 2022
Publicly Available Date Jun 26, 2023
Print ISSN 0360-2532
Publisher Taylor & Francis
Peer Reviewed Peer Reviewed
Volume 54
Issue 1
Pages 46-62
Keywords HepG2, HepaRG, hepatocytes, cytochrome P450, drug-drug interaction, CYP3A4, CYP2B6, pregnane X receptor, constitutive androstane receptor, in vitro techniques
Public URL


Downloadable Citations