Cytochrome P450 (CYP) enzymes (CYP)

The hepatic drug-metabolizing enzymes for berberine primarily consist of the Cytochrome P450 (CYP) superfamily and UDP-glucuronosyltransferases (UGTs). In the liver, berberine undergoes extensive Phase I metabolism, primarily mediated by CYP2D6, CYP1A2, and CYP3A4, which catalyze oxidative demethylation to form metabolites such as berberrubine and thalifendine (Guo et al., 2011; Liu et al., 2016). These metabolites are subsequently processed by Phase II enzymes, specifically UGT1A1 and UGT2B1, through glucuronidation to facilitate their biliary and renal excretion (Jabbarzadeh Kaboli et al., 2014). Beyond its role as a substrate, berberine is a potent inhibitor of several major CYPs, including CYP2D6, CYP3A4, and CYP2C9, which can lead to significant drug-drug interactions by elevating the plasma concentrations of co-administered medications (Guo et al., 2012). This inhibition is particularly concerning for drugs with narrow therapeutic windows, such as cyclosporine, tacrolimus, and warfarin (NIH, 2020). Additionally, genetic polymorphisms in these enzymes, especially CYP2D6, contribute to substantial inter-individual variability in berberine's pharmacokinetics and its potential for adverse interactions. Understanding these enzymatic interactions is critical for managing patients who use berberine as a supplement for metabolic or cardiovascular health.

Other names

Hepatic drug-metabolizing enzymesBerberine-metabolizing enzymesCytochrome P450 2D6 (CYP2D6)Cytochrome P450 1A2 (CYP1A2)Cytochrome P450 3A4 (CYP3A4)UDP-glucuronosyltransferase 1A1 (UGT1A1)UDP-glucuronosyltransferase 2B1 (UGT2B1)

Berberine serves as a substrate for oxidative demethylation by CYP enzymes (Phase I) and subsequent glucuronidation by UGTs (Phase II); it also acts as a reversible or time-dependent inhibitor of CYP2D6, CYP3A4, and CYP2C9.