In Vitro Metabolism of Donepezil in Liver Microsomes Using Non-Targeted Metabolomics

Abstract

Donepezil is a reversible acetylcholinesterase inhibitor that is currently the most commonly prescribed drug for the treatment of Alzheimer’s disease. In general, donepezil is known as a safe and well-tolerated drug, and it was not associated with liver abnormalities in several clinical trials. However, rare cases of drug-related liver toxicity have been reported since it has become commercially available. Few studies have investigated the metabolic profile of donepezil, and the mechanism of liver damage caused by donepezil has not been elucidated. In this study, the in vitro metabolism of donepezil was investigated using liquid chromatography–tandem mass spectrometry based on a non-targeted metabolomics approach. To identify metabolites, the data were subjected to multivariate data analysis and molecular networking. A total of 21 donepezil metabolites (17 in human liver microsomes, 21 in mice liver microsomes, and 17 in rat liver microsomes) were detected including 14 newly identified metabolites. One potential reactive metabolite was identified in rat liver microsomal incubation samples. Metabolites were formed through four major metabolic pathways: (1) O-demethylation, (2) hydroxylation, (3) N-oxidation, and (4) N-debenzylation. This study indicates that a non-targeted metabolomics approach combined with molecular networking is a reliable tool to identify and detect unknown drug metabolites.

Pharmacokinetic/Pharmacodynamic Models of an Alzheimer’s Drug, Donepezil, in Rats

“…The plasma concentration profiles of DMDon are also shown in Figure 2. DMDon is the major active metabolite of Don (Kim et al, 2021). The t max s of both doses occurred at 60-70 min after starting the infusion, and the C max were 10.0±2.8 and 13.8±8.9 ng/mL after 1.25 and 2.5 mg/kg doses, respectively.…”

“…The metabolic pathway of Don is complex and produces many metabolites, namely hydroxylation, N-oxidation, N-dealkylated, and O-dealkylated products by CYP3A4 and CYP2D6 in human liver microsomes (Cacabelos, 2007;Coin et al, 2016). It is especially known that Don is metabolized mainly into an active O-demethylated form, 6-O-desmethyl donepezil (DMDon) (Kim et al, 2021). These metabolites are further metabolized to form glucuronidation, which are then excreted into bile and urine (Matsui et.…”

Evaluation of the Drug-Induced Liver Injury Potential of Saxagliptin through Reactive Metabolite Identification in Rats

“…Liver microsomal incubation mixtures were prepared with 100 μM of saxagliptin and 1 mg/mL of microsomal proteins (RLM) in 100 mM of phosphate buffer (pH of 7.4). L-cysteine (100 mM), glutathione (2.5 mM), or UDPGA (5 mM) was added after pre-incubation with or without 100 mM L-cysteine at 37 °C for 5 min to an NADPH-generating system (1.3 mM of NADP + , 3.3 mM of G6P, 1 unit/mL of G6PDH, and 3.3 mM of MgCl 2 ) to initiate the microsomal reaction [ 16 ]. The reaction was stopped by adding cold acetonitrile after microsomal incubation for 2 h. The supernatant was injected into the Q Exactive Focus Orbitrap MS system (Thermo Fisher Scientific, Waltham, MA, USA) after centrifugation (Eppendorf, Hamburg, Germany).…”

Synthesis, acaricidal activity, and structure–activity relationships of novel phenyl trifluoroethyl thioether derivatives containing substituted benzyl groups

“…Many compounds containing a benzylamine group possess a broad spectrum of biocidal activity; for example, benznidazole for treating chagas disease and trypanosomiasis, 21 and donepezil which is an acetylcholinesterase inhibitor. 22 Furthermore, the benzylamine group has been used as an agrochemical in such compounds as acaricide tebufenpyrad and tolfenpyrad, 23 as well as the fungicide diflumetorim 24 and the herbicide beflubutamid. 25 Here, we focus on discovering new molecules with unique structures for pest control.…”