Evaluation of Carbazeran 4-Oxidation and <i>O</i><sup>6</sup>-Benzylguanine 8-Oxidation as Catalytic Markers of Human Aldehyde Oxidase: Impact of Cytosolic Contamination of Liver Microsomes

Xie, Jiarong; Saburulla, Nur Fazilah; Chen, Shiyan; Wong, Siew Heng; Yap, Ze Ping; Zhang, Linghua Harris; Lau, Aik Jiang

doi:10.1124/dmd.118.082099

Cited by 20 publications

(21 citation statements)

References 44 publications

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“…O 6 -Benzylguanine 8-Oxidation Assay. The assay was conducted according to our previous study (Xie et al, 2019), except that the substrate concentration was 5-600 mM, the incubation time was 75 minutes, and the enzymatic reaction was initiated by adding kidney cytosol (200 mg, 2 mg/ml final concentration).…”

Section: Methodsmentioning

confidence: 99%

“…Quantification of 4-Oxo-Carbazeran by UPLC-MS/MS. The UPLC-MS/MS system and the chromatographic and mass spectrometric conditions for analyzing 4-oxo-carbazeran and tolbutamide were reported in detail in our previous study (Xie et al, 2019). A calibration curve was constructed using weighted (1/x 2 ) linear leastsquares regression analysis of the peak area ratio (4-oxo-carbazeran to tolbutamide) versus amount of the metabolite standard added into the incubation mixture.…”

Section: Methodsmentioning

confidence: 99%

“…, where K i represents the equilibrium dissociation constant between the substrate and the binding site of the enzyme. The turnover number, unbound fraction, corrected K m , and unbound intrinsic clearance (Cl int,u ) were calculated as described in our previous study (Xie et al, 2019). Enzyme Inhibition Experiments.…”

Section: Methodsmentioning

confidence: 99%

“…AOX1 Protein Quantification by a Capillary Nano-Proteomic Immunoassay. The amount of AOX1 in cytosols was quantified in a capillary nano-proteomic immunoassay (SimpleWestern System; ProteinSimple), as described in our previous study (Xie et al, 2019).…”

Section: Methodsmentioning

confidence: 99%

“…In the present study, the primary objectives were to: 1) compare and contrast the effect of acolbifene (a benzopyran), bazedoxifene (an indole), and lasofoxifene (a tetrahydronaphthalene) on the catalytic activity of AOX1, as assessed by carbazeran 4-oxidation (Xie et al, 2019) catalyzed by human tissue cytosol and recombinant AOX1 enzyme; 2) determine whether the structural analogs (Supplemental Fig. 1) of bazedoxifene and lasofoxifene are inhibitors of AOX1; 3) explore how these SERMs bind to AOX1 active site, as evaluated by molecular-docking analyses; and 4) investigate the effect of estrone sulfate and estrone on the extent of AOX1 inhibition by bazedoxifene, given that bazedoxifene is administered clinically in combination with conjugated estrogens.…”

Section: Introductionmentioning

confidence: 99%

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In Vitro and In Silico Analyses of the Inhibition of Human Aldehyde Oxidase by Bazedoxifene, Lasofoxifene, and Structural Analogues

Chen

Austin-Muttitt

Zhang

et al. 2019

J Pharmacol Exp Ther

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Tamoxifen, raloxifene, and nafoxidine are selective estrogen receptor modulators (SERMs) reported to inhibit the catalytic activity of human aldehyde oxidase 1 (AOX1). How these drugs interact with AOX1 and whether other SERMs inhibit this drugmetabolizing enzyme are not known. Therefore, a detailed in vitro and in silico study involving parent drugs and their analogs was conducted to investigate the effect of specific SERMs, particularly acolbifene, bazedoxifene, and lasofoxifene on AOX1 catalytic activity, as assessed by carbazeran 4-oxidation, an AOX1-selective catalytic marker. The rank order in the potency (based on IC 50 values) of AOX1 inhibition by SERMs was raloxifene. bazedoxifene ∼ lasofoxifene. tamoxifen. acolbifene. Inhibition of liver cytosolic AOX1 by bazedoxifene, lasofoxifene, and tamoxifen was competitive, whereas that by raloxifene was noncompetitive. Loss of 1-azepanylethyl group increased the inhibitory potency of bazedoxifene, whereas the N-oxide group decreased it. The 7-hydroxy group and the substituted pyrrolidine ring attached to the tetrahydronaphthalene structure contributed to AOX1 inhibition by lasofoxifene. These results are supported by molecular-docking simulations in terms of predicted binding modes, encompassing binding orientation and efficiency, and analysis of key interactions, particularly hydrogen bonds. The extent of AOX1 inhibition by bazedoxifene was increased by estrone sulfate and estrone. In summary, SERMs differentially inhibited human AOX1 catalytic activity. Structural features of bazedoxifene and lasofoxifene contributed to AOX1 inhibition, whereas those of acolbifene rendered it considerably less susceptible to AOX1 inhibition. Overall, our novel biochemical findings and molecular-docking analyses provide new insights into the interaction between SERMs and AOX1. SIGNIFICANCE STATEMENT Aldehyde oxidase (AOX1) is a molybdo-flavoprotein and has emerged as a drug-metabolizing enzyme of potential therapeutic importance because drugs have been identified as AOX1 substrates. Selective estrogen receptor modulators (SERM), which are drugs used to treat and prevent various conditions, differentially inhibit AOX1 catalytic activity. Structural features of bazedoxifene and lasofoxifene contribute to AOX1 inhibition, whereas those of acolbifene render it considerably less susceptible to AOX1 inhibition. Our novel biochemical findings, together with molecular-docking analyses, provide new insights into the differential inhibitory effect of SERMs on the catalytic activity of human AOX1, how SERMs bind to AOX1, and increase our understanding of the AOX1 pharmacophore in the inhibition of AOX1 by drugs and other chemicals.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

In Vitro and In Silico Analyses of the Inhibition of Human Aldehyde Oxidase by Bazedoxifene, Lasofoxifene, and Structural Analogues

Chen

Austin-Muttitt

Zhang

et al. 2019

J Pharmacol Exp Ther

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Use of Human Intestinal and Hepatic Tissue Fractions and Microbiome as Models in Assessment of Drug Metabolism and its Impact on Oral Bioavailability

Zaher,

Zhang

2023

Oral Bioavailability and Drug Delivery

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Establishing a physiologically based pharmacokinetic framework for aldehyde oxidase and dual aldehyde oxidase‐CYP substrates

Izat,

Bolleddula,

Carione

et al. 2024

CPT Pharmacom & Syst Pharma

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Aldehyde oxidase (AO) contributes to the clearance of many approved and investigational small molecule drugs, which are often dual substrates of AO and drug‐metabolizing enzymes such as cytochrome P450s (CYPs). As such, the lack of established framework for quantitative translation of the clinical pharmacologic correlates of AO‐mediated clearance represents an unmet need. This study aimed to evaluate the utility of physiologically based pharmacokinetic (PBPK) modeling in the development of AO and dual AO‐CYP substrates. PBPK models were developed for capmatinib, idelalisib, lenvatinib, zaleplon, ziprasidone, and zoniporide, incorporating in vitro functional data from human liver subcellular fractions and human hepatocytes. Prediction of metabolic elimination with/without the additional empirical scaling factors (ESFs) was assessed. Clinical pharmacokinetics, human mass balance, and drug–drug interaction (DDI) studies with CYP3A4 modulators, where available, were used to refine/verify the models. Due to the lack of clinically significant AO‐DDIs with known AO inhibitors, the fraction metabolized by AO (fmAO) was verified indirectly. Clearance predictions were improved by using ESFs (GMFE ≤1.4‐fold versus up to fivefold with physiologically‐based scaling only). Observed fmi from mass balance studies were crucial for model verification/refinement, as illustrated by capmatinib, where the fmAO (40%) was otherwise underpredicted up to fourfold. Subsequently, independent DDI studies with ketoconazole, itraconazole, rifampicin, and carbamazepine verified the fmCYP3A4, with predicted ratios of the area under the concentration–time curve (AUCR) within 1.5‐fold of the observations. In conclusion, this study provides a novel PBPK‐based framework for predicting AO‐mediated pharmacokinetics and quantitative assessment of clinical DDI risks for dual AO‐CYP substrates within a totality‐of‐evidence approach.

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Evaluation of Carbazeran 4-Oxidation and O⁶-Benzylguanine 8-Oxidation as Catalytic Markers of Human Aldehyde Oxidase: Impact of Cytosolic Contamination of Liver Microsomes

Cited by 20 publications

References 44 publications

In Vitro and In Silico Analyses of the Inhibition of Human Aldehyde Oxidase by Bazedoxifene, Lasofoxifene, and Structural Analogues

In Vitro and In Silico Analyses of the Inhibition of Human Aldehyde Oxidase by Bazedoxifene, Lasofoxifene, and Structural Analogues

Use of Human Intestinal and Hepatic Tissue Fractions and Microbiome as Models in Assessment of Drug Metabolism and its Impact on Oral Bioavailability

Establishing a physiologically based pharmacokinetic framework for aldehyde oxidase and dual aldehyde oxidase‐CYP substrates

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Evaluation of Carbazeran 4-Oxidation and O6-Benzylguanine 8-Oxidation as Catalytic Markers of Human Aldehyde Oxidase: Impact of Cytosolic Contamination of Liver Microsomes

Cited by 20 publications

References 44 publications

In Vitro and In Silico Analyses of the Inhibition of Human Aldehyde Oxidase by Bazedoxifene, Lasofoxifene, and Structural Analogues

In Vitro and In Silico Analyses of the Inhibition of Human Aldehyde Oxidase by Bazedoxifene, Lasofoxifene, and Structural Analogues

Use of Human Intestinal and Hepatic Tissue Fractions and Microbiome as Models in Assessment of Drug Metabolism and its Impact on Oral Bioavailability

Establishing a physiologically based pharmacokinetic framework for aldehyde oxidase and dual aldehyde oxidase‐CYP substrates

Contact Info

Product

Resources

About

Evaluation of Carbazeran 4-Oxidation and O⁶-Benzylguanine 8-Oxidation as Catalytic Markers of Human Aldehyde Oxidase: Impact of Cytosolic Contamination of Liver Microsomes