Inhibition of human P450 enzymes by nicotinic acid and nicotinamide.

Article Details

Citation

Gaudineau C, Auclair K

Inhibition of human P450 enzymes by nicotinic acid and nicotinamide.

Biochem Biophys Res Commun. 2004 May 7;317(3):950-6. doi: 10.1016/j.bbrc.2004.03.137.

PubMed ID
15081432 [ View in PubMed
]
Abstract

Nicotinic acid has been used as a cholesterol-lowering agent for a few decades already, whereas the cytoprotective and antiviral properties of nicotinamide are slowly gaining attention. In both cases however, very high doses are needed to achieve a therapeutic effect, resulting in blood concentrations sometimes as high as 15 mM. Based on their common pyridine functionality, we hypothesized that these two molecules could inhibit human P450 enzymes. In vitro inhibition studies demonstrate that, at their therapeutic concentrations, both nicotinic acid and nicotinamide inhibit CYP2D6 (Ki = 3.8 +/- 0.3 and 19 +/- 4 mM, respectively). Nicotinamide also inhibits CYP3A4 (Ki = 13 +/- 3 mM) and CYP2E1 (Ki = 13 +/- 8 mM). As expected for nitrogen-containing heteroaromatic molecules, spectrophotometric analysis indicates that the inhibition occurs via coordination of the pyridine nitrogen atom to the heme iron.

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
NiacinCytochrome P450 2D6ProteinHumans
Unknown
Inhibitor
Details
NiacinCytochrome P450 2E1ProteinHumans
Unknown
Inhibitor
Details
NiacinCytochrome P450 3A4ProteinHumans
Unknown
Inhibitor
Details
NicotinamideCytochrome P450 2D6ProteinHumans
Unknown
Inhibitor
Details
NicotinamideCytochrome P450 2E1ProteinHumans
Unknown
Substrate
Inhibitor
Details
NicotinamideCytochrome P450 3A4ProteinHumans
Unknown
Inhibitor
Details