1
|
Francesconi V, Rizzo M, Pozzi C, Tagliazucchi L, Konchie Simo CU, Saporito G, Landi G, Mangani S, Carbone A, Schenone S, Santarém N, Tavares J, Cordeiro-da-Silva A, Costi MP, Tonelli M. Identification of Innovative Folate Inhibitors Leveraging the Amino Dihydrotriazine Motif from Cycloguanil for Their Potential as Anti- Trypanosoma brucei Agents. ACS Infect Dis 2024; 10:2755-2774. [PMID: 38953453 DOI: 10.1021/acsinfecdis.4c00113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Folate enzymes, namely, dihydrofolate reductase (DHFR) and pteridine reductase (PTR1) are acknowledged targets for the development of antiparasitic agents against Trypanosomiasis and Leishmaniasis. Based on the amino dihydrotriazine motif of the drug Cycloguanil (Cyc), a known inhibitor of both folate enzymes, we have identified two novel series of inhibitors, the 2-amino triazino benzimidazoles (1) and 2-guanidino benzimidazoles (2), as their open ring analogues. Enzymatic screening was carried out against PTR1, DHFR, and thymidylate synthase (TS). The crystal structures of TbDHFR and TbPTR1 in complex with selected compounds experienced in both cases a substrate-like binding mode and allowed the rationalization of the main chemical features supporting the inhibitor ability to target folate enzymes. Biological evaluation of both series was performed against T. brucei and L. infantum and the toxicity against THP-1 human macrophages. Notably, the 5,6-dimethyl-2-guanidinobenzimidazole 2g resulted to be the most potent (Ki = 9 nM) and highly selective TbDHFR inhibitor, 6000-fold over TbPTR1 and 394-fold over hDHFR. The 5,6-dimethyl tricyclic analogue 1g, despite showing a lower potency and selectivity profile than 2g, shared a comparable antiparasitic activity against T. brucei in the low micromolar domain. The dichloro-substituted 2-guanidino benzimidazoles 2c and 2d revealed their potent and broad-spectrum antitrypanosomatid activity affecting the growth of T. brucei and L. infantum parasites. Therefore, both chemotypes could represent promising templates that could be valorized for further drug development.
Collapse
Affiliation(s)
- Valeria Francesconi
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Marco Rizzo
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Cecilia Pozzi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena 53100, Italy
- Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (CIMMP), Via Luigi Sacconi 6, Sesto Fiorentino (FI) 50019, Italy
| | - Lorenzo Tagliazucchi
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
- Doctorate School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, Via Campi 287, Modena 41125, Italy
| | - Claude U Konchie Simo
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
| | - Giulia Saporito
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
| | - Giacomo Landi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena 53100, Italy
| | - Stefano Mangani
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena 53100, Italy
| | - Anna Carbone
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Silvia Schenone
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Nuno Santarém
- i3S - Institute for Research and Innovation in Health, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal
| | - Joana Tavares
- i3S - Institute for Research and Innovation in Health, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal
| | - Anabela Cordeiro-da-Silva
- i3S - Institute for Research and Innovation in Health, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal
- Department of Life Science, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, Porto 4050-313, Portugal
| | - Maria Paola Costi
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
| | - Michele Tonelli
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| |
Collapse
|
2
|
Ma Y, Zhang M, Deng Z, Wang X, Huang H, Yang K, Yuan B, Liu Y, Kang Z. Chiral carbon dots - a functional domain for tyrosinase Cu active site modulation via remote target interaction. NANOSCALE 2022; 14:1202-1210. [PMID: 34989754 DOI: 10.1039/d1nr07236f] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The nano-hybrid enzyme is an ideal catalytic system that integrates various advantages from biocatalysis and nanocatalysis into homogeneous and heterogeneous catalysis. However, great efforts are still needed to fully understand the interactions between nanoparticles and enzymes. Here, we show chiral carbon dots (CDs) as a new functional domain for tyrosinase Cu active site modulation via remote target interaction. Three kinds of chiral CDs (LCDs-1/-2/-3; DCDs-1/-2/-3) were fabricated by thermal treatment of citric acid and L/D-aspartic acid. Then a series of CDs/tyrosinase composites (namely, nano-hybrid-enzymes) were prepared, demonstrating good regulation of enzyme catalytic kinetics. Especially, we find that LCDs-1 is an irreversible inhibitor with great inhibition effect while the others are all reversible inhibitors. Furthermore, it is suggested by both experiments and all-atom molecular dynamics simulations that the joint effect of LCDs-1 and tyrosinase makes LCDs-1 serve as a new functional domain, which has a distinguished ability to control the conformational changes of the key sites of the active center of the tyrosinase (e.g., H60) and thus the escaping behavior of copper ions and the catalytic activity. This work opens a new route for nano-hybrid-enzyme design and enzyme activity regulation with chiral carbon materials as functional domains via remote target interaction.
Collapse
Affiliation(s)
- Yurong Ma
- Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, China.
| | - Mengling Zhang
- Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, China.
| | - Zhixiong Deng
- Center for Soft Condensed Matter Physics and Interdisciplinary Research and School of Physical Science and Technology, Soochow University, Suzhou, 215006, China.
| | - Xiting Wang
- Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, China.
| | - Hui Huang
- Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, China.
| | - Kai Yang
- Center for Soft Condensed Matter Physics and Interdisciplinary Research and School of Physical Science and Technology, Soochow University, Suzhou, 215006, China.
| | - Bing Yuan
- Center for Soft Condensed Matter Physics and Interdisciplinary Research and School of Physical Science and Technology, Soochow University, Suzhou, 215006, China.
| | - Yang Liu
- Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, China.
| | - Zhenhui Kang
- Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, China.
- Macao Institute of Materials Science and Engineering, Macau University of Science and Technology, Taipa 999078, Macau SAR, China.
| |
Collapse
|
3
|
Souza SA, Held A, Lu WJ, Drouhard B, Avila B, Leyva-Montes R, Hu M, Miller BR, Ng HL. Mechanisms of allosteric and mixed mode aromatase inhibitors. RSC Chem Biol 2021; 2:892-905. [PMID: 34458816 PMCID: PMC8341375 DOI: 10.1039/d1cb00046b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/17/2021] [Indexed: 11/21/2022] Open
Abstract
Aromatase (CYP19) catalyzes the last biosynthetic step of estrogens in mammals and is a primary drug target for hormone-related breast cancer. However, treatment with aromatase inhibitors is often associated with adverse effects and drug resistance. In this study, we used virtual screening targeting a predicted cytochrome P450 reductase binding site on aromatase to discover four novel non-steroidal aromatase inhibitors. The inhibitors have potencies comparable to the noncompetitive tamoxifen metabolite, endoxifen. Our two most potent inhibitors, AR11 and AR13, exhibit both mixed-type and competitive-type inhibition. The cytochrome P450 reductase-CYP19 coupling interface likely acts as a transient binding site. Our modeling shows that our inhibitors bind better at different sites near the catalytic site. Our results predict the location of multiple ligand binding sites on aromatase. The combination of modeling and experimental results supports the important role of the reductase binding interface as a low affinity, promiscuous ligand binding site. Our new inhibitors may be useful as alternative chemical scaffolds that may show different adverse effects profiles than current clinically used aromatase inhibitors.
Collapse
Affiliation(s)
- Samson A Souza
- Department of Biochemistry and Molecular Biophysics, Kansas State University Manhattan KS USA
| | - Abby Held
- Department of Chemistry, Truman State University Kirksville MO USA
| | - Wenjie J Lu
- Department of Chemistry, University of Hawai'i at Mānoa Honolulu HI USA
| | - Brendan Drouhard
- Department of Biochemistry and Molecular Biophysics, Kansas State University Manhattan KS USA
| | - Bryant Avila
- Department of Biochemistry and Molecular Biophysics, Kansas State University Manhattan KS USA
| | - Raul Leyva-Montes
- Department of Biochemistry and Molecular Biophysics, Kansas State University Manhattan KS USA
| | - Michelle Hu
- Department of Chemistry, University of Hawai'i at Mānoa Honolulu HI USA
| | - Bill R Miller
- Department of Chemistry, Truman State University Kirksville MO USA
| | - Ho Leung Ng
- Department of Biochemistry and Molecular Biophysics, Kansas State University Manhattan KS USA
| |
Collapse
|
4
|
Carter SJ, Ferecskó AS, King L, Ménochet K, Parton T, Chappell MJ. A mechanistic modelling approach for the determination of the mechanisms of inhibition by cyclosporine on the uptake and metabolism of atorvastatin in rat hepatocytes using a high throughput uptake method. Xenobiotica 2019; 50:415-426. [PMID: 31389297 DOI: 10.1080/00498254.2019.1652781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Determine the inhibition mechanism through which cyclosporine inhibits the uptake and metabolism of atorvastatin in fresh rat hepatocytes using mechanistic models applied to data generated using a high throughput oil spin method.Atorvastatin was incubated in fresh rat hepatocytes (0.05-150 nmol/ml) with or without 20 min pre-incubation with 10 nmol/ml cyclosporine and sampled over 0.25-60 min using a high throughput oil spin method. Micro-rate constant and macro-rate constant mechanistic models were ranked based on goodness of fit values.The best fitting model to the data was a micro-rate constant mechanistic model including non-competitive inhibition of uptake and competitive inhibition of metabolism by cyclosporine (Model 2). The association rate constant for atorvastatin was 150-fold greater than the dissociation rate constant and 10-fold greater than the translocation into the cell. The association and dissociation rate constants for cyclosporine were 7-fold smaller and 10-fold greater, respectively, than atorvastatin. The simulated atorvastatin-transporter-cyclosporine complex derived using the micro-rate constant parameter estimates increased in line with the incubation concentration of atorvastatin.The increased amount of data generated with the high throughput oil spin method, combined with a micro-rate constant mechanistic model helps to explain the inhibition of uptake by cyclosporine following pre-incubation.
Collapse
Affiliation(s)
- Simon J Carter
- Biomedical and Biological Systems Laboratory, School of Engineering, University of Warwick, Coventry, United Kingdom
| | | | | | | | | | - Michael J Chappell
- Biomedical and Biological Systems Laboratory, School of Engineering, University of Warwick, Coventry, United Kingdom
| |
Collapse
|
5
|
Zhang S, Gedalanga PB, Mahendra S. Biodegradation Kinetics of 1,4-Dioxane in Chlorinated Solvent Mixtures. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9599-9607. [PMID: 27486928 DOI: 10.1021/acs.est.6b02797] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study investigated the impacts of individual chlorinated solvents and their mixtures on aerobic 1,4-dioxane biodegradation by Pseudonocardia dioxanivorans CB1190. The established association of these co-occurring compounds suggests important considerations for their respective biodegradation processes. Our kinetics and mechanistic studies demonstrated that individual solvents inhibited biodegradation of 1,4-dioxane in the following order: 1,1-dichloroethene (1,1-DCE) > cis-1,2-diochloroethene (cDCE) > trichloroethene (TCE) > 1,1,1-trichloroethane (TCA). The presence of 5 mg L(-1) 1,1-DCE completely inhibited 1,4-dioxane biodegradation. Subsequently, we determined that 1,1-DCE was the strongest inhibitor of 1,4-dioxane biodegradation by bacterial pure cultures exposed to chlorinated solvent mixtures as well as in environmental samples collected from a site contaminated with chlorinated solvents and 1,4-dioxane. Inhibition of 1,4-dioxane biodegradation rates by chlorinated solvents was attributed to delayed ATP production and down-regulation of both 1,4-dioxane monooxygenase (dxmB) and aldehyde dehydrogenase (aldH) genes. Moreover, increasing concentrations of 1,1-DCE and cis-1,2-DCE to 50 mg L(-1) respectively increased 5.0-fold and 3.5-fold the expression of the uspA gene encoding a universal stress protein. In situ natural attenuation or enhanced biodegradation of 1,4-dioxane is being considered for contaminated groundwater and industrial wastewater, so these results will have implications for selecting 1,4-dioxane bioremediation strategies at sites where chlorinated solvents are present as co-contaminants.
Collapse
Affiliation(s)
- Shu Zhang
- Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
| | - Phillip B Gedalanga
- Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
| | - Shaily Mahendra
- Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
| |
Collapse
|
6
|
Dong Z, Ekins S, Polli JE. Quantitative NTCP pharmacophore and lack of association between DILI and NTCP Inhibition. Eur J Pharm Sci 2014; 66:1-9. [PMID: 25220493 DOI: 10.1016/j.ejps.2014.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 08/22/2014] [Accepted: 09/06/2014] [Indexed: 01/05/2023]
Abstract
The human sodium taurocholate cotransporting polypeptide (NTCP) is a hepatic bile acid transporter. Inhibition of NTCP uptake may potentially also prevent hepatitis B virus (HBV) infection. The first objective was to develop a quantitative pharmacophore for NTCP inhibition. Recent studies showed that hepatotoxic drugs could inhibit bile acid uptake into hepatocytes, without inhibiting canalicular efflux, and cause bile acid elevation in plasma. Hence, a second objective was to examine whether NTCP inhibition is associated with drug induced liver injury (DILI). Twenty-seven drugs from our previous study were used as the training set to develop a quantitative pharmacophore. From secondary screening from a drug database, six retrieved drugs and three drugs not retrieved by the model were tested for NTCP inhibition. Tertiary screening involved drugs known to cause DILI and not cause DILI. Overall, ninety-four drugs were assessed for hepatotoxicity and were assessed relative to NTCP inhibition. The quantitative pharmacophore possessed one hydrogen bond acceptor, one hydrogen bond donor, a hydrophobic feature, and excluded volumes. From 94 drugs, NTCP inhibitors and non-inhibitors were approximately equally distributed across the drugs of most DILI concern, less DILI concern, and no DILI concern, indicating no relationship between NTCP inhibition and DILI risk. Hence, an approach to treat HBV via NTCP inhibition is not expected to be associated with DILI.
Collapse
Affiliation(s)
- Zhongqi Dong
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA
| | - Sean Ekins
- Collaborations in Chemistry, 5616 Hilltop Needmore Road, Fuquay Varina, NC 27526, USA
| | - James E Polli
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA.
| |
Collapse
|
7
|
Vivian D, Polli JE. Mechanistic interpretation of conventional Michaelis-Menten parameters in a transporter system. Eur J Pharm Sci 2014; 64:44-52. [PMID: 25169756 DOI: 10.1016/j.ejps.2014.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/22/2014] [Accepted: 08/17/2014] [Indexed: 11/24/2022]
Abstract
The aim was to elucidate how steps in drug translocation by a solute carrier transporter impact Michaelis-Menten parameters Km, Ki, and Vmax. The first objective was to derive a model for carrier-mediated substrate translocation and perform sensitivity analysis with regard to the impact of individual microrate constants on Km, Ki, and Vmax. The second objective was to compare underpinning microrate constants between compounds translocated by the same transporter. Equations for Km, Ki, and Vmax were derived from a six-state model involving unidirectional transporter flipping and reconfiguration. This unidirectional model is applicable to co-transporter type solute carriers, like the apical sodium-dependent bile acid transporter (ASBT) and the proton-coupled peptide cotransporter (PEPT1). Sensitivity analysis identified the microrate constants that impacted Km, Ki, and Vmax. Compound comparison using the six-state model employed regression to identify microrate constant values that can explain observed Km and Vmax values. Results yielded some expected findings, as well as some unanticipated effects of microrate constants on Km, Ki, and Vmax. Km and Ki were found to be equal for inhibitors that are also substrates. Additionally, microrate constant values for certain steps in transporter functioning influenced Km and Vmax to be low or high.
Collapse
Affiliation(s)
- Diana Vivian
- University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
| | - James E Polli
- University of Maryland School of Pharmacy, Baltimore, MD 21201, USA.
| |
Collapse
|
8
|
Petzer A, Harvey BH, Petzer JP. The interactions of azure B, a metabolite of methylene blue, with acetylcholinesterase and butyrylcholinesterase. Toxicol Appl Pharmacol 2014; 274:488-93. [DOI: 10.1016/j.taap.2013.10.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 10/04/2013] [Accepted: 10/14/2013] [Indexed: 02/06/2023]
|
9
|
Gorman GS, Coward L, Darby A, Rasberry B. Effects of herbal supplements on the bioactivation of chemotherapeutic agents. J Pharm Pharmacol 2013; 65:1014-25. [PMID: 23738729 DOI: 10.1111/jphp.12055] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 02/11/2013] [Indexed: 12/17/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the impact of commercially available, over-the-counter herbal supplements (St John's wort, black cohosh and ginger root extract) on the metabolic activation of tamoxifen and irinotecan. METHODS Co-incubation of each drug and supplement combination over a range of concentrations was conducted in human liver microsomes and the decrease in the rate of active metabolite formation was monitored using high-performance liquid chromatography tandem mass spectrometry. Data was analysed using non-linear regression analysis and Dixon plots to determine the dominant mechanism of inhibition and to estimate the Ki and IC50 values of the commercial supplements. KEY FINDINGS The data suggest that black cohosh was the strongest inhibitor tested in this study for both CYP450 and carboxyesterase mediated biotransformation of tamoxifen and irinotecan, respectively, to their active metabolites. St John's wort was a stronger inhibitor compared with ginger root extract for tamoxifen (CYP mediated pathway), while ginger root extract was a stronger inhibitor compared with St John's wort for the carboxyesterase mediated pathway. CONCLUSIONS Commercially available supplements are widely used by patients and their potential impact on the efficacy of the chemotherapy is often unknown. The clinical significance of these results needs to be evaluated in a comprehensive clinical trial.
Collapse
Affiliation(s)
- Gregory S Gorman
- McWhorter School of Pharmacy, Samford University, Birmingham, AL 35229, USA.
| | | | | | | |
Collapse
|
10
|
Dong Z, Ekins S, Polli JE. Structure-activity relationship for FDA approved drugs as inhibitors of the human sodium taurocholate cotransporting polypeptide (NTCP). Mol Pharm 2013; 10:1008-19. [PMID: 23339484 DOI: 10.1021/mp300453k] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The hepatic bile acid uptake transporter sodium taurocholate cotransporting polypeptide (NTCP) is less well characterized than its ileal paralog, the apical sodium dependent bile acid transporter (ASBT), in terms of drug inhibition requirements. The objectives of this study were (a) to identify FDA approved drugs that inhibit human NTCP, (b) to develop pharmacophore and Bayesian computational models for NTCP inhibition, and (c) to compare NTCP and ASBT transport inhibition requirements. A series of NTCP inhibition studies were performed using FDA approved drugs, in concert with iterative computational model development. Screening studies identified 27 drugs as novel NTCP inhibitors, including irbesartan (Ki = 11.9 μM) and ezetimibe (Ki = 25.0 μM). The common feature pharmacophore indicated that two hydrophobes and one hydrogen bond acceptor were important for inhibition of NTCP. From 72 drugs screened in vitro, a total of 31 drugs inhibited NTCP, while 51 drugs (i.e., more than half) inhibited ASBT. Hence, while there was inhibitor overlap, ASBT unexpectedly was more permissive to drug inhibition than was NTCP, and this may be related to NTCP possessing fewer pharmacophore features. Findings reflected that a combination of computational and in vitro approaches enriched the understanding of these poorly characterized transporters and yielded additional chemical probes for possible drug-transporter interaction determinations.
Collapse
Affiliation(s)
- Zhongqi Dong
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , 20 Penn Street, Baltimore, Maryland 21201, USA
| | | | | |
Collapse
|
11
|
Kolhatkar V, Polli JE. Structural requirements of bile acid transporters: C-3 and C-7 modifications of steroidal hydroxyl groups. Eur J Pharm Sci 2012; 46:86-99. [PMID: 22387310 DOI: 10.1016/j.ejps.2012.02.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 01/27/2012] [Accepted: 02/20/2012] [Indexed: 10/28/2022]
Abstract
The apical sodium dependent bile acid transporter (ASBT) and sodium-taurocholate cotransporting polypeptide (NTCP) are potential prodrug targets, but the structural requirements for these transporters are incompletely defined. The objective of this study was to evaluate the effect of C-3 and C-7 substitution on bile acid interaction with these bile acid transporters. Nineteen bile acid analogs were tested against ASBT and NTCP for binding, as well as translocation. Results indicated that ASBT and NTCP accommodated a wide range of substituents for binding, but all major C-7 modifications resulted in analogs that did not demonstrate active uptake by either ASBT or NTCP. A C-3 modification that was not tolerated at C-7 still afforded translocation via ASBT and NTCP, confirming the relative unacceptability of C-7 modification. Both ASBT and NTCP demonstrated a generally similar binding potency. Results suggest that drug conjugation to the C-3 hydroxyl group, rather than C-7, has potential to lead to a successful prodrug targeting ASBT and NTCP.
Collapse
Affiliation(s)
- Vidula Kolhatkar
- Univerisity of Maryland, School of Pharmacy, Baltimore, MD 21201, USA
| | | |
Collapse
|
12
|
Keogh JP. Membrane transporters in drug development. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2012; 63:1-42. [PMID: 22776638 DOI: 10.1016/b978-0-12-398339-8.00001-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Membrane transporters have wide, but specific tissue distributions. They can impact on multiple endogenous and xenobiotic processes. Knowledge and awareness within the pharmaceutical industry of their impact on drug absorption, distribution, metabolism and elimination (ADME) and drug safety is growing rapidly. Clinically important transporter-mediated drug-drug interactions (DDIs) have been observed. Up to nine diverse transporters are implicated in the DDIs of a number of widely prescribed drugs, posing a significant challenge to the pharmaceutical industry. There is a complex interplay between multiple transporters and/or enzymes in the ADME and pharmacogenomics of drugs. Integrating these different mechanisms to understand their relative contributions to ADME is a key challenge. Many different factors complicate the study of membrane transporters in drug development. These include a lack of specific substrates and inhibitors, non-standard in vitro tools, and competing/complementary mechanisms (e.g. passive permeability and metabolism). Discovering and contextualizing the contribution of membrane transporters to drug toxicity is a significant new challenge. Drug interactions with key membrane transporters are routinely assessed for central nervous system (CNS) drug discovery therapies, but are not generally considered across the wider drug discovery. But, there is interest in utilizing membrane transporters as drug delivery agents. Computational modeling approaches, notably physiology-based/pharmacokinetic (PB/PK) modeling are increasingly applied to transporter interactions, and permit integration of multiple ADME mechanisms. Because of the range of tissues and transporters of interest, robust transporter, in vitro to in vivo, scaling factors are required. Empirical factors have been applied, but absolute protein quantitation will probably be required.
Collapse
|