Human cytochrome P450 (CYP) enzymes, as membrane-bound hemoproteins, play important roles in the detoxification of drugs, cellular metabolism, and homeostasis.

Drug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems.

2023年8月17日 · Another factor in drug metabolism is enzyme induction. Enzymes are induced by repeated use of the same chemical. The body becomes accustomed to the constant presence of the drug and compensates by increasing the production of …

Drug-metabolizing enzymes (DMEs) perform a crucial role in the metabolism of xenobiotics, especially the drugs. These DMEs also lead to the conversion of prodrugs into their active form, which mediates more pharmacological activity.

In this article, we review the contributions of genetic polymorphisms to major individual variations in drug pharmacotherapy, focusing specifically on the pharmacogenomics of phase-I drug metabolizing enzymes and transporters.

Metabolism. Drug-metabolizing enzymes are crucial in the extent of drug biotransformation. Although the liver is considered the major organ responsible for drug biotransformation, other organs such as the intestines, lungs, and kidneys also contribute to drug metabolism.

Drug-metabolizing enzymes are called mixed-function oxidase or monooxygenase and containing many enzymes including cytochrome P450, cytochrome b5, and NADPH-cytochrome P450 reductase and other components.

As drug concentration increases, metabolism shifts from first-order to zero-order kinetics. The most important enzyme system of phase I metabolism is cytochrome P-450 (CYP450), a microsomal superfamily of isoenzymes that catalyzes the oxidation of many drugs.

We use the Remote Sensing and Signaling Theory (RSST) to examine the roles of DMEs and transporters in intratissue, interorgan, and interorganismal communication via metabolites and signaling molecules.

Cytochrome P450 enzymes are the main drug metabolising enzymes (xenobiotic inactivators) in humans, and these are the primary contributors to Phase I oxidative metabolism of drugs and other chemicals.