Liver detoxification pathways

Liver detoxification pathways describe the series of enzymatic processes, primarily occurring in the liver, that convert lipophilic substances—including drugs, xenobiotics, and metabolic byproducts—into more hydrophilic metabolites for excretion. This system is broadly categorized into Phase I (functionalization, mainly via cytochrome P450s) and Phase II (conjugation, such as glucuronidation, sulfation, acetylation, glutathione, and amino acid conjugation), which sequentially process toxicants. Phase I generates intermediate metabolites, some of which can be more reactive and potentially harmful, while Phase II reactions generally further increase hydrophilicity and facilitate excretion via urine or bile. These pathways are regulated by nuclear receptors and are critical for drug metabolism, protection against environmental toxins, and prevention of cellular damage, but can also contribute to disease states if dysregulated or genetically impaired.

Other names

Hepatic biotransformation pathwaysPhase I and Phase II detoxificationLiver metabolic detoxification

Induction or inhibition of Phase I or Phase II enzyme activity Alteration of metabolic rates for co-administered drugs