Cytochrome P450 Induction Assay

Human cytochrome P450 (CYP450) enzymes play an essential role in drug metabolism. Even subtle changes in the activities of CYP enzymes may cause severe drug-drug interactions. Creative Bioarray aims to help our clients with evaluating the interaction potential of your compounds.

CYP450 Induction Assay Introduction

  • Why CYP450 induction assay?
    • Cytochrome P450s (CYPs) are a family of enzymes that play a significant role in drug metabolism. The induction of CYPs is associated with an increase in the incidence of clinical drug-drug interactions (DDI).
    • If the CYP enzyme is induced by the compound, it may increase the metabolism of the concurrent treatment, or it may itself (auto-induced) lead to a decrease in plasma levels and a potential decrease in the drug's efficacy.
    • The induction of CYP enzymes can also lead to toxicity by increasing the formation of reactive metabolites.

Therefore, it is necessary to understand the potential interactions with the combination therapy in advance to guide the development of drugs and determine possible DDI or clinical DDI research needs.

  • CYP450 induction mechanisms

Nuclear receptors, such as the aromatic pregnane X receptor (PXR), constitutive androstane receptor (CAR), and hydrocarbon receptor (AhR), mediate drug-induced changes in the expression of phase I and phase II enzymes and transporters. The CYP1A2, CYP2B6, and CYP3A4 gene expression induction can be used as the sensitive representative endpoints of AhR, CAR, and PXR activation, respectively.

Mechanisms of CYP inductionFigure 1. Mechanisms of CYP induction (Manikandan, 2018).

Brief Protocol

Three families of P450 enzymes (CYP1, CYP2, and CYP3) are all involved in the metabolic process, and CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4, 3A5 are responsible for the metabolism of the majority of drugs. There are approximately 75% of the total metabolic enzymes of the CYP450 family.

It is recommended first to evaluate CYP1A2, CYP2B6, and CYP3A4, as they are induced by different nuclear receptors. The positive in vitro results of CYP3A4 indicate the need for follow-up induction studies for CYP2C8, CYP2C9, and CYP2C19, because these isoforms are also induced by activating the pregnane X receptor (PXR).

Test PlatformCryopreserved human hepatocytes (3 donors)
CYP IsoformsCYP1A2, CYP2B6, and CYP3A4/5
For CYP2C8, CYP2C9 and CYP2C19, please contact us for more information
Drug ConcentrationMultiple concentrations in triplicate determination; (dependent upon unbound Cmax, dose, solubility, and cytotoxicity, different concentrations available)
Measurement MethodEnzymatic activity: LC-MS/MS quantification.
mRNA levels: qRT-PCR.
DataEmax, EC50, CYPs activity, mRNA levels of CYPs, fold induction relative to the positive control, Raw Data, Report

Quotation and Ordering

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  1. EMA. Guideline on the investigation of drug interactions (June 2012)
  2. Hariparsad, Niresh, et al. "Considerations from the IQ induction working group in response to drug-drug interaction guidance from regulatory agencies: focus on downregulation, CYP2C induction, and CYP2B6 positive control." Drug Metabolism and Disposition 45.10 (2017): 1049-1059.
  3. Manikandan.; et al. "Cytochrome P450 structure, function and clinical significance: a review." Current drug targets 19.1 (2018): 38-54.

For research use only. Not for any other purpose.