Corynoline, an isoquinoline alkaloid isolated from the genus Corydalis, has been demonstrated to show multiple pharmacological effects including inhibition of acetylcholinesterase, inhibition of cell adhesion, fungitoxic and cytotoxic activity. The present study focused on its metabolism and metabolism-based herb-drug interactions. After corynoline was incubated with human liver microsomes (HLMs) in the presence of NADPH, two metabolites (M-1 and M-2) were formed. Chemical inhibition experiments and assays with recombinant CYP isoforms showed that CYP2C9 was mainly involved in the formation of M-1 and CYP3A4 mainly catalysed the production of M-2. Among seven major CYP isoforms tested, corynoline showed strong inhibitory effects on the activities of CYP3A4 and CYP2C9, with an IC(50) of 3.3 ± 0.9 µm and 31.5 ± 0.5 µm, respectively. Kinetic analysis showed that inhibition of CYP3A4 by corynoline was best fit to a noncompetitive manner with K(i) of 3.2 µm, while inhibition of CYP2C9 by corynoline was best fit to a competitive manner with K(i) of 6.3 µm. Additionally, corynoline exhibited time-dependent inhibition (TDI) toward CYP3A4. The inactivation kinetic parameters (K(I) and k(inact) ) were calculated to be 6.8 µm and 0.07 min(-1) , respectively. These data are of significance for the application of corynoline and corynoline-containing herbs.

Download full-text PDF

Source
http://dx.doi.org/10.1002/ptr.3255DOI Listing

Publication Analysis

Top Keywords

cyp isoforms
12
corynoline
8
herb-drug interactions
8
interactions corynoline
8
corynoline best
8
best fit
8
inhibition
6
identification cytochrome
4
cytochrome p450
4
p450 cyp
4

Similar Publications

The well-established calcineurin inhibitor, tacrolimus, as an immunosuppressive agent, is widely prescribed after organ transplantation. Cytochrome P450 (CYP 450) isoforms are responsible for the metabolism of many features associated with food parameters like phytochemicals, juices, and fruits. This review article summarizes the findings of previous studies to help predict the efficacy or side effects of tacrolimus in the presence of food variables.

View Article and Find Full Text PDF

Background: Cytochromes P450 (CYPs) are heme-containing oxidoreductase enzymes with mono-oxygenase activity. Human CYPs catalyze the oxidation of a great variety of chemicals, including xenobiotics, steroid hormones, vitamins, bile acids, procarcinogens, and drugs.

Findings: In our review article, we discuss recent data evidencing that the same CYP isoform can be involved in both bioactivation and detoxification reactions and convert the same substrate to different products.

View Article and Find Full Text PDF

1-Nitropyrene Metabolism and Health Risk: Identification of Key Enzymes, Pathways, and Metabolites Using a Multimethod Approach.

Environ Health (Wash)

December 2023

Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.

Polycyclic aromatic hydrocarbon (PAH) derivatives have a widespread presence in the environment and even the human body, but their metabolism and potential risk remain unclear. In this study, we used molecular dynamics simulations and density functional theory to calculate the metabolic mechanism of 1-nitropyrene (1-NP), an important PAH derivative. The results showed that cytochrome P450 enzymes (CYPs) can metabolize 1-NP, with CYP 2A13 and CYP 2E1 being important enzyme isoforms, because they had lower binding affinities (-16.

View Article and Find Full Text PDF

Idiosyncratic drug-induced liver injury (iDILI) by flucloxacillin presents as both cholestatic and hepatocellular injury. Its mechanistic steps are explored in the present analysis as limited data exist on the cascade of events leading to iDILI in patients with an established diagnosis assessed for causality by the Roussel Uclaf Causality Assessment Method (RUCAM). Studies with human liver microsomes showed that flucloxacillin is a substrate of cytochrome P450 (CYP) with ist preferred isoforms CYP 3A4/3A7 that toxified flucloxacillin toward 5'-hydroxymethylflucloxacillin, which was cytotoxic to human biliary epithelial cell cultures, simulating human cholestatic injury.

View Article and Find Full Text PDF

Many factors cause inter-person variability in the activity and expression of liver cytochrome P450 (CYP) drug-metabolizing enzymes, leading to variable drug exposure and treatment outcomes. Several liver-enriched transcription factors (TFs) are associated with CYP expression, with estrogen receptor alpha (ESR1) and constitutive androstane receptor (CAR or NR1I3) being the two top factors. ESR1 and NR1I3 undergo extensive alternative splicing that results in numerous splice isoforms, but how these splice isoforms associate with CYP expression is unknown.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!