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Updated: Aug 16, 2026
An Intestine/Liver Microphysiological System for Drug Pharmacokinetic and Toxicological Assessment
Published on: December 3, 2020
Quantitative PCR assay for cytochromes P450 2B and 3A induction in rat precision-cut liver slices: correlation study
Xiaoming Cui1, Ann Thomas, Yi Han
1Department of Drug Metabolism and Pharmacokinetics, Schering-Plough Research Institute, K15-D209, 2015 Galloping Hill Rd., Kenilworth, NJ 07033, USA. xiaoming.cui@spcorp.com
Introduction:
In drug development, new chemical entities that cause cytochrome P450 induction are considered to be undesirable since P450 induction is linked to tumor formation and may compromise the evaluation of drug safety when autoinduction results in poor drug exposure.
Methods:
We evaluated the use of the precision-cut liver slice as a model for measuring induction of cytochrome P450 in rats. Quantitative real-time reverse-transcription polymerase chain reaction was used to analyze the induction of selected forms of cytochrome P450 at the mRNA level. Firstly, the system was validated against known inducers of CYP2B and 3A. Subsequently, 26 proprietary compounds were tested in rat liver slices and rats in vivo for CYP2B and 3A induction.
Results:
Exposure of liver slices to the known CYP2B inducers phenobarbital, benzoyl-pyridine, cabarmazepine, metyrapone, RU486 and dexamethasone caused elevation of CYP2B1/2 expression 10- to 40-fold compared to the control values. The CYP3A inducers PCN, dexamethasone, nicardipine, nifedipine, clotrimazole and RU486 induced a 4- to 50-fold expression of CYP3A14. For 26 proprietary compounds, a correlation with an R(2) value of 0.74 was established between the induction of CYP2B expression in liver slices and that in rats in vivo. When liver slice results were used to predict the induction of CYP2B in rats in vivo, the success rate was 91%. The induction of CYP3A in rats in vivo was analyzed by Western blot, then quantified by densitometry. There was a good correlation between CYP3A induction in liver slices and induction in vivo as assessed by Western blot, with an 86% positive prediction rate.
Discussion:
The use of liver slices in combination with TaqMan technology provides a good model for predicting CYP induction in the rat. This method is useful for identifying compounds with CYP2B and 3A induction liability in the early phase of drug discovery.
Insights
Precision-cut liver slices accurately predict cytochrome P450 induction in rats, identifying drug liabilities early. This method aids in early drug discovery by assessing CYP2B and CYP3A induction potential.
Area of Science:
- Pharmacology and Toxicology
- Drug Metabolism and Pharmacokinetics
- In Vitro Models
Background:
- Cytochrome P450 (CYP) induction by new chemical entities is a concern in drug development due to links with tumor formation and altered drug exposure.
- Autoinduction of CYP can compromise drug safety evaluations.
- Identifying CYP inducers early is crucial for successful drug development.
Purpose of the Study:
- To evaluate precision-cut liver slices as a model for measuring CYP induction in rats.
- To validate the liver slice model against known CYP inducers.
- To assess the predictive capability of the liver slice model for CYP2B and CYP3A induction in vivo.
Main Methods:
- Utilized quantitative real-time reverse-transcription polymerase chain reaction (TaqMan technology) to analyze CYP mRNA levels.
- Validated the precision-cut liver slice system with known CYP2B and CYP3A inducers.
- Tested 26 proprietary compounds in rat liver slices and in rats in vivo for CYP2B and CYP3A induction.
Main Results:
- Known CYP2B inducers elevated CYP2B1/2 mRNA 10- to 40-fold in liver slices.
- Known CYP3A inducers elevated CYP3A14 mRNA 4- to 50-fold in liver slices.
- A strong correlation (R²=0.74) was observed between CYP2B induction in liver slices and in vivo.
- The liver slice model achieved a 91% success rate in predicting CYP2B induction in vivo.
- Good correlation and an 86% positive prediction rate were found for CYP3A induction in liver slices versus in vivo (Western blot).
Conclusions:
- Precision-cut liver slices combined with TaqMan technology provide a reliable model for predicting CYP induction in rats.
- This in vitro method is effective for early identification of drug candidates with CYP2B and CYP3A induction liabilities.
- The model supports informed decision-making in the early stages of drug discovery.
