Comparison of In Vitro Stereoselective Metabolism of Bupropion in Human, Monkey, Rat, and Mouse Liver Microsomes

Striking stereoselective disposition of the antidepressant and smoking cessation aid bupropion and its active metabolites observed clinically influence patients' response to BUP therapy and its clinically important drug-drug interactions (DDI) with CYP2D6 substrates. However, understanding of the biochemical mechanisms responsible is incomplete. This study comprehensively examined hepatic and extrahepatic stereoselective metabolism of BUP in vitro. Racemic-, R-and S-BUP was incubated separately with pooled cellular fractions of human liver (microsomes, HLMs; S9 fractions, HLS9 fractions; and cytosols, HLCs) and intestinal (microsomes, HIMs; S9 fractions, HIS9 fractions; and cytosols, HICs) and cofactors. Formation of diastereomers of 4-hydroxyBUP (OHBUP), threohydroBUP (THBUP) and erythrohydroBUP (EHBUP) were quantified using a novel chiral UHPLC/MS/MS method. Racemic BUP (but not R-or S-BUP) was found suitable to determine stereoselective metabolism of BUP; both enantiomers showed complete racemization.Compared to that of RR-THBUP, the in vitro intrinsic clearance (Cl int ) for the formation of SS-THBUP was 42-, 19-, and 8.3-fold higher in HLMs, HLS9 fractions and HLCs, respectively; Cl int for the formation of SS-OHBUP and RS-EHBUP were also higher (2.7to 3.9-fold) than their R-derived counterparts. In cellular fractions of human intestine, ≥95% of total reduction was accounted by the formation of RR-THBUP. Ours is the first to demonstrate marked stereoselective reduction of BUP in HLCs, HIMs, HIS9 fractions and HICs, providing the first evidence for tissue-and cellular fraction-dependent stereoselective metabolism of BUP. These data may serve as the first critical step This article has not been copyedited and formatted. The final version may differ from this version.

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“…fractions observed in the present study concur with the previous findings (Bhattacharya et al, 2019;Sager et al, 2016).…”

Section: Discussionsupporting

confidence: 94%

“…Higher Cl int for the reduction of BUP to SS-THBUP (42.1-and 19.2-fold) was observed in HLMs and HLS9 fractions, respectively, compared to the Cl int for the formation of RR-THBUP. The extent of stereoselectivity was smaller (<14-fold) in previous reports from HLMs and HLS9 fractions (Bhattacharya et al, 2019;Sager et al, 2016).…”

Section: Discussioncontrasting

confidence: 66%

Stereoselective Metabolism of Bupropion to Active Metabolites in Cellular Fractions of Human Liver and Intestine

Bamfo

Desta

2022

Drug Metab Dispos

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“…Interestingly, M1 diastereomer ratio (R = M1-D1/ M1-D2) was reversed between HLM (1 ≦ R≦ 3.4) and RLM (0.12 ≦ R ≦ 1) tests, possibly due to species difference. Such a high interspecific difference was also observed in the metabolism of R and S-bupropion which contained a tert-butyl group [20]. These results suggest that the steric bulkiness of the tert-butyl group could cause the observed species difference in stereo-selective metabolism.…”

Section: Metabolic Pathwaymentioning

confidence: 60%

“…M6 may be produced from BocMC via H 2 O adduction followed by cyclization as shown in Fig. 5 by reference to metabolism of bupropion [20][21][22][23], but this speculation still requires additional studies on structural identification and production mechanism. Chemical structures of M1, M4 and M6 proposed M1 to be further metabolized in microsomal incubation, forming M6 as an intermediate, finally yielding M4.…”

Section: Metabolic Pathwaymentioning

confidence: 99%

Human and rat microsomal metabolites of N-tert-butoxycarbonylmethamphetamine and its urinary metabolites in rat

et al. 2021

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Purpose N-tert-Butoxycarbonylmethamphetamine (BocMA), a masked derivative of methamphetamine (MA), converts into MA under acidic condition and potentially acts as a precursor to MA following ingestion. To investigate the metabolism and excretion of BocMA, metabolism tests were conducted using human liver microsomes (HLM), rat liver microsomes (RLM) and rat. Methods BocMA metabolites were analyzed after 1000-ng/mL BocMA incubation with microsomes for 3, 8, 13, 20, 30, and 60 min. Rats were administered intraperitoneal injections (20 mg/kg) of BocMA and their urine was collected in intervals for 72 h. Metabolites were detected by liquid chromatography–tandem mass spectrometry with five authentic standards. Results Several metabolites including 4-hydroxy-BocMA, N-tert-butoxycarbonylephedrine and N-tert-butoxycarbonyl-cathinone were detected for HLM and RLM. In the administration test, three glucuronides of hydroxylated metabolites were detected. The total recovery values of BocMA and the metabolites during the first 72 h accounted for only 0.3% of the administered dose. Throughout the microsomal and administration experiments, MAs were not detected. Conclusion Hydroxylation, carbonylation and N-demethylation were proposed as metabolic pathways. However, BocMA and phase I metabolites were hardly detected in urine. This study provides useful information to interpret the possibility of BocMA intake as the cause of MA detection in biological sample.

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“…Various studies have also demonstrated that the metabolism and substrate specificities of C. jacchus CYPs are analogous to those of human CYPs. For example, an antidepressant and smoking cessation drug bupropion and an anti-arrhythmic drug propafenone are hydrolyzed by the CYP2D6 enzyme in hepatic microsomes from the C. jacchus at levels similar to those of the human microsomes [ 194 , 195 , 196 ]. Similarly, both human and C. jacchus CYP enzymes metabolized the carcinogen aflatoxin B 1 (AFB), a risk factor in the development of HCC, at comparable levels [ 197 ].…”

Section: Drug Metabolism Studies With Marmoset Esc-derived Hlcsmentioning

confidence: 99%

Utility of Common Marmoset (Callithrix jacchus) Embryonic Stem Cells in Liver Disease Modeling, Tissue Engineering and Drug Metabolism

Aravalli

Steer

2020

Genes

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The incidence of liver disease is increasing significantly worldwide and, as a result, there is a pressing need to develop new technologies and applications for end-stage liver diseases. For many of them, orthotopic liver transplantation is the only viable therapeutic option. Stem cells that are capable of differentiating into all liver cell types and could closely mimic human liver disease are extremely valuable for disease modeling, tissue regeneration and repair, and for drug metabolism studies to develop novel therapeutic treatments. Despite the extensive research efforts, positive results from rodent models have not translated meaningfully into realistic preclinical models and therapies. The common marmoset Callithrix jacchus has emerged as a viable non-human primate model to study various human diseases because of its distinct features and close physiologic, genetic and metabolic similarities to humans. C. jacchus embryonic stem cells (cjESC) and recently generated cjESC-derived hepatocyte-like cells (cjESC-HLCs) could fill the gaps in disease modeling, liver regeneration and metabolic studies. They are extremely useful for cell therapy to regenerate and repair damaged liver tissues in vivo as they could efficiently engraft into the liver parenchyma. For in vitro studies, they would be advantageous for drug design and metabolism in developing novel drugs and cell-based therapies. Specifically, they express both phase I and II metabolic enzymes that share similar substrate specificities, inhibition and induction characteristics, and drug metabolism as their human counterparts. In addition, cjESCs and cjESC-HLCs are advantageous for investigations on emerging research areas, including blastocyst complementation to generate entire livers, and bioengineering of discarded livers to regenerate whole livers for transplantation.

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Comparison of In Vitro Stereoselective Metabolism of Bupropion in Human, Monkey, Rat, and Mouse Liver Microsomes

Cited by 7 publications

References 57 publications

Stereoselective Metabolism of Bupropion to Active Metabolites in Cellular Fractions of Human Liver and Intestine

Stereoselective Metabolism of Bupropion to Active Metabolites in Cellular Fractions of Human Liver and Intestine

Human and rat microsomal metabolites of N-tert-butoxycarbonylmethamphetamine and its urinary metabolites in rat

Utility of Common Marmoset (Callithrix jacchus) Embryonic Stem Cells in Liver Disease Modeling, Tissue Engineering and Drug Metabolism

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