Investigation on the in vitro metabolism of bicyclol using liver microsomes, hepatocytes and human recombinant cytochrome P450 enzymes

Abstract

1. In vitro metabolism of bicyclol was studied using liver microsomes, hepatocytes and human recombinant cytochrome P450 enzymes. Liquid chromatography-benchtop orbitrap mass spectrometry technique was utilised to identify the metabolites.

2. A total of 19 metabolites, including 5 new metabolites (M2, M3, M4, M5 and M16) were tentatively identified. Among these metabolites, M6&M8 (demethylenation), M9&M10 (demethylation) and M19 (glucuronidation) were the major metabolites.

3. In glutathione (GSH)-supplemented liver microsomes, 5 new GSH conjugates were found and tentatively identified. The formation was assumed to be through demethylenation of methylenedioxyphenyl to form catechol derivatives, which further underwent oxidation to form ortho-quinone intermediates, reacting with GSH to form stable adducts.

4. CYP3A4 and 2C19 were demonstrated to be the major enzymes responsible for the bioactivation of bicyclol.

5. This study provided valuable information on the metabolic fate of bicyclol in liver microsomes and hepatocytes, and the bioactivation pathways were reported for the first time, which would be helpful for us to understand the potential drug-drug interactions and the possible side effect of this drug.

Keywords:

• Bicyclol
• metabolic pathways
• bioactivation
• demethylenation
• methylenedioxyphenyl

Author contribution

Experiment was designed by: Fengping Chen, Yu qi Yan

Experiment was performed by: Fengping Chen, Haizhu Zou

Data were analysed by: Fengping Chen, Ping Zhang

Manuscript was written by: Fengping Chen

Manuscript was reviewed by: Yuqi Yan

Disclosure statement

The authors report no declarations of interest.

Additional information

Funding

This study was financially supported by Guangdong Basic and Applied Basic Research Foundation (2020A1515110484) and the Fundamental Research Funds for the Central University (21620307).