Xenobiotic

A xenobiotic is a chemical substance found within an organism that is not naturally produced or expected to be present within the organism. The term comes from Greek roots meaning "strange" or "foreign" combined with "biotic". Examples include pharmaceuticals, pesticides, industrial chemicals, synthetic compounds, and naturally occurring compounds present in abnormally high concentrations. Xenobiotics are not a therapeutic target in the traditional sense (such as a receptor, enzyme, or transporter); they represent a broad class of chemical substances that are foreign to organisms. They are not a single molecule, receptor, enzyme, or transporter. Therefore, 'xenobiotic' is not a molecular target for drug development. The relevant therapeutic targets in this context are the enzymes and transporters involved in xenobiotic metabolism (e.g., cytochrome P450 enzymes, glutathione S-transferases, UDP-glucuronosyltransferases, ABC transporters, MRPs) and xenobiotic receptors (e.g., Pregnane X receptor (PXR), Constitutive androstane receptor (CAR), Peroxisome proliferator-activated receptors (PPARα, PPARγ)) which regulate the expression of biotransformation and transport genes.

Other names

Foreign chemicalsexogenous chemicalsenvironmental pollutantsxenobiotic substances