Related Experiment Video
Updated: Jun 4, 2026
10:44
Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
Anandamide oxidation by wild-type and polymorphically expressed CYP2B6 and CYP2D6
Chitra Sridar1, Natasha T Snider, Paul F Hollenberg
1Department of Pharmacology, University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, MI 48109-5632, USA.
Drug Metabolism and Disposition: the Biological Fate of Chemicals
|February 4, 2011
Summary
Cytochrome P450 enzymes CYP2B6 and CYP2D6 metabolize anandamide into products with lower cannabinoid receptor affinity. These metabolites are degraded faster, impacting endocannabinoid system signaling and potential therapeutic targets.
Area of Science:
- Biochemistry
- Neuroscience
- Pharmacology
Background:
- Anandamide, an endogenous cannabinoid, regulates physiological and pathophysiological processes.
- Cytochrome P450 (P450) enzymes metabolize anandamide into various products.
- CYP2B6 and CYP2D6 are polymorphic P450 isoforms in the brain, influenced by external factors.
Purpose of the Study:
- Investigate anandamide metabolism by wild-type and polymorphic CYP2B6 and CYP2D6.
- Characterize the resulting hydroxylated and epoxygenated anandamide metabolites.
- Determine the pharmacological properties and degradation pathways of these metabolites.
Main Methods:
- In vitro metabolism assays using wild-type and mutant CYP2B6 and CYP2D6 isoforms.
- Pharmacological binding studies with rat brain cannabinoid CB1 receptor.
- Degradation studies using rat brain homogenates and specific hydrolase inhibitors.
Main Results:
- Significant differences in anandamide metabolism by CYP2B6 and CYP2D6 variants were observed.
- Formation of 20-hydroxyeicosatetraenoic acid ethanolamide (20-HETE-EA) and 14,15-epoxyeicosatetraenoic acid ethanolamide (14,15-EET-EA) varied between isoforms.
- Metabolites 20-HETE-EA and 14,15-EET-EA exhibited lower CB1 receptor affinity and faster degradation than anandamide via FAAH and EH pathways.
Conclusions:
- CYP2B6 and CYP2D6 significantly influence anandamide metabolism, producing distinct bioactive products.
- The generated metabolites have altered signaling properties compared to anandamide.
- Findings offer insights into P450-endocannabinoid system interactions and potential therapeutic strategies targeting FAAH and EH inhibitors.
Related Concept Videos
01:28Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...
01:19Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems
Phase I biotransformation reactions are integral to drug metabolism, predominantly involving oxidative, reductive, and hydrolytic transformations. Chief among these are oxidative reactions, which enhance the hydrophilicity of xenobiotics and introduce polar functional groups to facilitate their elimination from the body.
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
01:27Pharmacogenetics of Drug Metabolism: Overview
Genetic polymorphism in drug metabolism is crucial to the inter-individual variability observed in drug responses. Drug metabolism primarily involves the chemical modification of drugs and other xenobiotics to enhance their elimination by increasing their polarity. Two main classes of enzymes mediate this biotransformation process: Phase I enzymes, primarily cytochrome P450s, catalyze oxidation and reduction reactions, while other enzymes, such as esterases, mediate hydrolysis, and Phase II...
01:11Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
01:27Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...
01:17Drug Metabolism: Phase I Reactions
A phase I reaction is a biochemical process that introduces a functionally reactive polar group to a substance. This transformation predominantly occurs in the liver, facilitated by the cytochrome P450 system of hemoproteins situated in the lipophilic endoplasmic reticulum of cells. The metabolite generated through this process can have varying polarities. If it is sufficiently polar, it can be easily excreted in the urine due to its water compatibility. However, if the metabolite is nonpolar,...