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Knockenhauer KE, Copeland RA. The importance of binding kinetics and drug-target residence time in pharmacology. Br J Pharmacol 2024; 181:4103-4116. [PMID: 37160660 DOI: 10.1111/bph.16104] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/11/2023] Open
Abstract
A dominant assumption in pharmacology throughout the 20th century has been that in vivo target occupancy-and attendant pharmacodynamics-depends on the systemic concentration of drug relative to the equilibrium dissociation constant for the drug-target complex. In turn, the duration of pharmacodynamics is temporally linked to the systemic pharmacokinetics of the drug. Yet, there are many examples of drugs for which pharmacodynamic effect endures long after the systemic concentration of a drug has waned to (equilibrium) insignificant levels. To reconcile such data, the drug-target residence time model was formulated, positing that it is the lifetime (or residence time) of the binary drug-target complex, and not its equilibrium affinity per se, that determines the extent and duration of drug pharmacodynamics. Here, we review this model, its evolution over time, and its applications to natural ligand-macromolecule biology and synthetic drug-target pharmacology.
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Tian G, Suarez J, Zhang Z, Connolly P, Ahn K. Potent Phenylpyridine and Oxodihydrofuran Inhibitors of Cyclooxygenase-2: Optimization toward a Long Residence Time with Balanced Internal Energetics. Biochemistry 2021; 60:2407-2418. [PMID: 34293856 DOI: 10.1021/acs.biochem.1c00294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Long residence time enzyme inhibitors with a two-step binding mechanism are characterized by a high internal energy barrier for target association. This raises the question of whether optimizing residence time via further increasing this internal energy barrier would inevitably lead to insufficient target occupancy in vivo due to slow, time-dependent binding. We attempted to address this question during optimization of cyclooxygenase-2 (COX-2) inhibitors. Defining long residence time drugs with acceptable association and dissociation rate constants required for sufficient target occupancy and sustained efficacy, which we termed "balanced internal energetics", provides an important criterion for successful progression during lead optimization. Despite the advancement of several COX-2 inhibitors to marketed drugs, their detailed inhibition kinetics have been surprisingly limiting especially during the structure-activity relationship process mainly due to the lack of robust kinetic assays. Herein, we describe a reoptimized COX enzymatic assay and a novel MS-based assay enabling detailed mechanistic studies for identifying long residence time COX-2 inhibitors with balanced internal energetics. These efforts led to the discovery of promising leads possessing dissociation half-lives of ≤40 h, much greater than the values of 6 and 0.71 h for two marketed drugs, etoricoxib and celecoxib, respectively. Importantly, the inhibition rate constants remain comparable to those of the marketed drugs and above the lower limits set by the criteria of balanced internal energetics, predicting sufficient target occupancy required for efficacy. Taken together, this study demonstrates the feasibility of increasing the internal energy barrier as a viable approach for lead optimization toward discovering long residence time drug candidates.
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Borisov DV, Veselovsky AV. [Ligand-receptor binding kinetics in drug design]. BIOMEDITSINSKAIA KHIMIIA 2020; 66:42-53. [PMID: 32116225 DOI: 10.18097/pbmc20206601042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Traditionally, the thermodynamic values of affinity are considered as the main criterion for the development of new drugs. Usually, these values for drugs are measured <i>in vitro</i> at steady concentrations of the receptor and ligand, which are differed from <i>in vivo</i> environment. Recent studies have shown that the kinetics of the process of drug binding to its receptor make significant contribution in the drug effectiveness. This has increased attention in characterizing and predicting the rate constants of association and dissociation of the receptor ligand at the stage of preclinical studies of drug candidates. A drug with a long residence time can determine ligand-receptor selectivity (kinetic selectivity), maintain pharmacological activity of the drug at its low concentration in vivo. The paper discusses the theoretical basis of protein-ligand binding, molecular determinants that control the kinetics of the drug-receptor binding. Understanding the molecular features underlying the kinetics of receptor-ligand binding will contribute to the rational design of drugs with desired properties.
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Affiliation(s)
- D V Borisov
- Institute of Biomedical Chemistry, Moscow, Russia
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Upreti R, Naredo G, Faqehi AMM, Hughes KA, Stewart LH, Walker BR, Homer NZM, Andrew R. Simultaneous pharmacokinetic and pharmacodynamic analysis of 5α-reductase inhibitors and androgens by liquid chromatography tandem mass spectrometry. Talanta 2015; 131:728-35. [PMID: 25281165 PMCID: PMC4196769 DOI: 10.1016/j.talanta.2014.07.087] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/25/2014] [Accepted: 07/30/2014] [Indexed: 11/29/2022]
Abstract
Benign prostatic hyperplasia and prostate cancer can be treated with the 5α-reductase inhibitors, finasteride and dutasteride, when pharmacodynamic biomarkers are useful in assessing response. A novel method was developed to measure the substrates and products of 5α-reductases (testosterone, 5α-dihydrotestosterone (DHT), androstenedione) and finasteride and dutasteride simultaneously by liquid chromatography tandem mass spectrometry, using an ABSciex QTRAP(®) 5500, with a Waters Acquity™ UPLC. Analytes were extracted from serum (500 µL) via solid-phase extraction (Oasis(®) HLB), with (13)C3-labelled androgens and d9-finasteride included as internal standards. Analytes were separated on a Kinetex C18 column (150 × 3 mm, 2.6 µm), using a gradient run of 19 min. Temporal resolution of analytes from naturally occurring isomers and mass +2 isotopomers was ensured. Protonated molecular ions were detected in atmospheric pressure chemical ionisation mode and source conditions optimised for DHT, the least abundant analyte. Multiple reaction monitoring was performed as follows: testosterone (m/z 289 → 97), DHT (m/z 291 → 255), androstenedione (m/z 287 → 97), dutasteride (m/z 529 → 461), finasteride (m/z 373 → 317). Validation parameters (intra- and inter-assay precision and accuracy, linearity, limits of quantitation) were within acceptable ranges and biological extracts were stable for 28 days. Finally the method was employed in men treated with finasteride or dutasteride; levels of DHT were lowered by both drugs and furthermore the substrate concentrations increased.
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Affiliation(s)
- Rita Upreti
- Endocrinology, University/British Heart Foundation Centre for Cardiovascular Science, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
| | - Gregorio Naredo
- Mass Spectrometry Core, Wellcome Trust Clinical Research Facility, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
| | - Abdullah M M Faqehi
- Endocrinology, University/British Heart Foundation Centre for Cardiovascular Science, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
| | - Katherine A Hughes
- Endocrinology, University/British Heart Foundation Centre for Cardiovascular Science, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
| | - Laurence H Stewart
- Department of Urology, NHS Lothian, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, United Kingdom.
| | - Brian R Walker
- Endocrinology, University/British Heart Foundation Centre for Cardiovascular Science, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom; Mass Spectrometry Core, Wellcome Trust Clinical Research Facility, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
| | - Natalie Z M Homer
- Mass Spectrometry Core, Wellcome Trust Clinical Research Facility, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
| | - Ruth Andrew
- Endocrinology, University/British Heart Foundation Centre for Cardiovascular Science, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom; Mass Spectrometry Core, Wellcome Trust Clinical Research Facility, Queen׳s Medical Research Institute, University of Edinburgh, 47, Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
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Upreti R, Hughes KA, Livingstone DEW, Gray CD, Minns FC, Macfarlane DP, Marshall I, Stewart LH, Walker BR, Andrew R. 5α-reductase type 1 modulates insulin sensitivity in men. J Clin Endocrinol Metab 2014; 99:E1397-406. [PMID: 24823464 PMCID: PMC4207930 DOI: 10.1210/jc.2014-1395] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
CONTEXT 5α-Reductase (5αR) types 1 and 2 catalyze the A-ring reduction of steroids, including androgens and glucocorticoids. 5α-R inhibitors lower dihydrotestosterone in benign prostatic hyperplasia; finasteride inhibits 5αR2, and dutasteride inhibits both 5αR2 and 5αR1. In rodents, loss of 5αR1 promotes fatty liver. OBJECTIVE Our objective was to test the hypothesis that inhibition of 5αR1 causes metabolic dysfunction in humans. DESIGN, SETTING, AND PARTICIPANTS This double-blind randomized controlled parallel group study at a clinical research facility included 46 men (20-85 years) studied before and after intervention. INTERVENTION Oral dutasteride (0.5 mg daily; n = 16), finasteride (5 mg daily; n = 16), or control (tamsulosin; 0.4 mg daily; n = 14) was administered for 3 months. MAIN OUTCOME MEASURE Glucose disposal was measured during a stepwise hyperinsulinemic-euglycemic clamp. Data are mean (SEM). RESULTS Dutasteride and finasteride had similar effects on steroid profiles, with reduced urinary androgen and glucocorticoid metabolites and reduced circulating DHT but no change in plasma or salivary cortisol. Dutasteride, but not finasteride, reduced stimulation of glucose disposal by high-dose insulin (dutasteride by -5.7 [3.2] μmol/kg fat-free mass/min, versus finasteride +7.2 [3.0], and tamsulosin +7.0 [2.0]). Dutasteride also reduced suppression of nonesterified fatty acids by insulin and increased body fat (by 1.6% [0.6%]). Glucose production and glycerol turnover were unchanged. Consistent with metabolic effects of dutasteride being mediated in peripheral tissues, mRNA for 5αR1 but not 5αR2 was detected in human adipose tissue. CONCLUSION Dual inhibition of 5αRs, but not inhibition of 5αR2 alone, modulates insulin sensitivity in human peripheral tissues rather than liver. This may have important implications for patients prescribed dutasteride for prostatic disease.
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Affiliation(s)
- Rita Upreti
- University/British Heart Foundation Centre for Cardiovascular Science (R.U., K.A.H., D.E.W.L., D.P.M., I.M., B.R.W., R.A.) and Clinical Research Imaging Centre (C.D.G.), University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom; and Radiology (F.C.M.) and Urology (L.H.S.) Departments, National Health Service Lothian University Hospitals Division, Western General Hospital, Edinburgh EH4 2XU, United Kingdom
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Lundahl A, Lennernäs H, Knutson L, Bondesson U, Hedeland M. Identification of Finasteride Metabolites in Human Bile and Urine by High-Performance Liquid Chromatography/Tandem Mass Spectrometry. Drug Metab Dispos 2009; 37:2008-17. [DOI: 10.1124/dmd.109.027870] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Rajagopalan R, Misialek S, Stevens SK, Myszka DG, Brandhuber BJ, Ballard JA, Andrews SW, Seiwert SD, Kossen K. Inhibition and Binding Kinetics of the Hepatitis C Virus NS3 Protease Inhibitor ITMN-191 Reveals Tight Binding and Slow Dissociative Behavior. Biochemistry 2009; 48:2559-68. [DOI: 10.1021/bi900038p] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Ravi Rajagopalan
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - Shawn Misialek
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - Sarah K. Stevens
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - David G. Myszka
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - Barbara J. Brandhuber
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - Joshua A. Ballard
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - Steven W. Andrews
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - Scott D. Seiwert
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
| | - Karl Kossen
- InterMune Inc., 3280 Bayshore Boulevard, Brisbane, California 94005, Biosensor Tools, 1588 East Connecticut Drive, Salt Lake City, Utah 84132, and Array Biopharma, 3200 Walnut Street, Boulder, Colorado 80301
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Holzgrabe U, Bennack E. [5-Alpha reductase inhibitors--benign prostatic hypertrophy and much more]. PHARMAZIE IN UNSERER ZEIT 2008; 37:310-314. [PMID: 18570285 DOI: 10.1002/pauz.200700274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Ulrike Holzgrabe
- Institut f. Pharmazie und LMC, Universität Würzburg, Am Hubland, 97074 Würzburg.
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Suzuki K, Nishiyama T, Hara N, Yamana K, Takahashi K, Labrie F. Importance of the intracrine metabolism of adrenal androgens in androgen-dependent prostate cancer. Prostate Cancer Prostatic Dis 2007; 10:301-6. [PMID: 17387321 DOI: 10.1038/sj.pcan.4500956] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The metabolic pathways of androgens and processes by which androgens induce re-growth after androgen deprivation therapy in prostate cancer have not been fully elucidated. In this study, finasteride decreased PSA secretion in medium containing testosterone, androstenedione, androstenediol and dehydroepiandrosterone, whereas dihydrotestosterone (DHT)- and hydroxy-flutamide-induced PSA production was not inhibited by finasteride in LNCaP-FGC cells. The present data show that adrenal androgen precursors do not directly interact with androgen receptors (ARs) but are converted to DHT via the intraprostatic metabolic pathways, resulting in the induction of LNCaP activity. This is the first report confirming this mechanism experimentally and also suggest the use of combined therapies that target ARs and prevent the formation of DHT within prostate cancer cells to achieve optimal therapeutic efficacy.
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Affiliation(s)
- K Suzuki
- Division of Urology, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, Asahimachi 1-757, Niigata 951-8510, Japan.
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Copeland RA, Pompliano DL, Meek TD. Drug-target residence time and its implications for lead optimization. Nat Rev Drug Discov 2006; 5:730-9. [PMID: 16888652 DOI: 10.1038/nrd2082] [Citation(s) in RCA: 1056] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Much of drug discovery today is predicated on the concept of selective targeting of particular bioactive macromolecules by low-molecular-mass drugs. The binding of drugs to their macromolecular targets is therefore seen as paramount for pharmacological activity. In vitro assessment of drug-target interactions is classically quantified in terms of binding parameters such as IC(50) or K(d). This article presents an alternative perspective on drug optimization in terms of drug-target binary complex residence time, as quantified by the dissociative half-life of the drug-target binary complex. We describe the potential advantages of long residence time in terms of duration of pharmacological effect and target selectivity.
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Affiliation(s)
- Robert A Copeland
- Department of Enzymology and Mechanistic Pharmacology, at GlaxoSmithKline, UP1345, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, USA.
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Xu Y, Dalrymple SL, Becker RE, Denmeade SR, Isaacs JT. Pharmacologic Basis for the Enhanced Efficacy of Dutasteride against Prostatic Cancers. Clin Cancer Res 2006; 12:4072-9. [PMID: 16818707 DOI: 10.1158/1078-0432.ccr-06-0184] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Prostatic dihydrotestosterone (DHT) concentration is regulated by precursors from systemic circulation and prostatic enzymes of androgen metabolism, particularly 5alpha-reductases (i.e., SRD5A1 and SRD5A2). Therefore, the levels of expression SRD5A1 and SRD5A2 and the antiprostatic cancer growth response to finasteride, a selective SRD5A2 inhibitor, versus the dual SRD5A1 and SRD5A2 inhibitor, dutasteride, were compared. EXPERIMENTAL DESIGN Real-time PCR and enzymatic assays were used to determine the levels of SRD5A1 and SRD5A2 in normal versus malignant rat and human prostatic tissues. Rats bearing the Dunning R-3327H rat prostate cancer and nude mice bearing LNCaP or PC-3 human prostate cancer xenografts were used as model systems. Tissue levels of testosterone and DHT were determined using liquid chromatography-mass spectrometry. RESULTS Prostate cancer cells express undetectable to low levels of SRD5A2 but elevated levels of SRD5A1 activity compared with nonmalignant prostatic tissue. Daily oral treatment of rats with the SRD5A2 selective inhibitor, finasteride, reduces prostate weight and DHT content but did not inhibit R-3327H rat prostate cancer growth or DHT content in intact (i.e., noncastrated) male rats. In contrast, daily oral treatment with even a low 1 mg/kg/d dose of the dual SRD5A1 and SRD5A2 inhibitor, dutasteride, reduces both normal prostate and H tumor DHT content and weight in intact rats while elevating tissue testosterone. Daily oral treatment with finasteride significantly (P < 0.05) inhibits growth of LNCaP human prostate cancer xenografts in intact male nude mice, but this inhibition is not as great as that by equimolar oral dosing with dutasteride. This anticancer efficacy is not equivalent, however, to that produced by castration. Only combination of dutasteride and castration produces a greater tumor inhibition (P < 0.05) than castration monotherapy against androgen-responsive LNCaP cancers. In contrast, no response was induced by dutasteride in nude mice bearing androgen-independent PC-3 human prostatic cancer xenografts. CONCLUSIONS These results document that testosterone is not as potent as DHT but does stimulate prostate cancer growth, thus combining castration with dutasteride enhances therapeutic efficacy.
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Affiliation(s)
- Yi Xu
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland 21231, USA
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Biruss B, Valenta C. Skin permeation of different steroid hormones from polymeric coated liposomal formulations. Eur J Pharm Biopharm 2006; 62:210-9. [PMID: 16202573 DOI: 10.1016/j.ejpb.2005.08.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Revised: 08/10/2005] [Accepted: 08/10/2005] [Indexed: 10/25/2022]
Abstract
In this study, the effect of various polymers (polycarbophil, chitosan-EDTA, polymeric emulsifier and carrageenan) on the permeation, the chemical and microbial stability of 17-beta-estradiol, progesterone, cyproterone acetate (cpa) and finasteride incorporated in DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) liposomes has been investigated. The liposomes contained 1% (w/w) of the steroid hormones. Standard diffusion experiments were performed. Drug stability was monitored by analysing the steroid hormone content in the different formulations over a time period of 8 weeks and visually inspecting for microbial contamination. In addition, viscosity measurements were performed. The permeation rate could be improved by addition of polymeric agents depending on their type and drug. In all tested formulations, finasteride exhibited the highest diffusion. Both the chemical and the microbial stability of the hormones were significantly improved by the polymers in comparison to the pure liposomes after an observation period of 8 weeks. After that time microbial stability was still evident for all semisolid formulations. In contrast to this in the pure liposomes already after 2 weeks the steroid drugs showed complete insufficient chemical stability and microbial contamination. Additional rheological measurements indicated an influence of the polymers and drugs on the viscosity in all formulations. The elasticity predominated in nearly all polymeric formulations.
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Affiliation(s)
- Babette Biruss
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria
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Pierucci-Lagha A, Covault J, Feinn R, Nellissery M, Hernandez-Avila C, Oncken C, Morrow AL, Kranzler HR. GABRA2 alleles moderate the subjective effects of alcohol, which are attenuated by finasteride. Neuropsychopharmacology 2005; 30:1193-203. [PMID: 15702134 DOI: 10.1038/sj.npp.1300688] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
GABA(A) receptors are involved in the subjective effects of alcohol. Endogenous neuroactive steroids interact with GABA(A) receptors to mediate several behavioral effects of alcohol in rodents. Based on a haplotypic association of alcohol dependence with the gene encoding the GABA(A) receptor alpha-2 subunit (GABRA2), we examined whether GABRA2 alleles are associated with the subjective response to alcohol. We also examined whether finasteride (a 5-alpha steroid reductase inhibitor), which blocks the synthesis of some neuroactive steroids, reduces the subjective response to alcohol. In all, 27 healthy social drinkers (15 males) completed a randomized, double-blind, placebo-controlled study of high-dose finasteride. After being pretreated with study drug, subjects consumed three alcoholic drinks. Subjective effects were measured repeatedly over the ascending blood alcohol curve. To examine the moderating role of genetic variation in GABRA2, a single-nucleotide polymorphism that was informative in association studies was included as a factor in the analysis. Subjects homozygous for the more common A-allele (n=7) showed more subjective effects of alcohol than did individuals with one or two copies of the alcohol dependence-associated G-allele (n=20, including two homozygotes). Among the A-allele homozygotes, there was a greater reduction in several subjective effects during the finasteride session compared to the placebo session. These findings provide preliminary evidence that the risk of alcoholism associated with GABRA2 alleles may be related to differences in the subjective response to alcohol. The effects of finasteride provide indirect evidence for a mediating role of neuroactive steroids in some of the subjective effects of alcohol.
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Affiliation(s)
- Amira Pierucci-Lagha
- Department of Psychiatry, Alcohol Research Center, University of Connecticut School of Medicine, Farmington, CT 06030, USA
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Lazier CB, Thomas LN, Douglas RC, Vessey JP, Rittmaster RS. Dutasteride, the dual 5alpha-reductase inhibitor, inhibits androgen action and promotes cell death in the LNCaP prostate cancer cell line. Prostate 2004; 58:130-44. [PMID: 14716738 DOI: 10.1002/pros.10340] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Reduction of T to DHT by 5alphaR in the prostate enhances androgenic activity for most targets. Inhibition of 5alphaR activity with finasteride attenuates androgen action in men and animal models. The objective of this study was to compare and contrast the effects of a potent new 5alphaR inhibitor, dutasteride, with finasteride in the LNCaP prostate cancer cell line. METHODS LNCaP cells were incubated for varying times with T or DHT in steroid-free medium in the absence or presence of increasing doses of dutasteride or finasteride and the effects on 5alphaR activity, PSA accumulation in the medium, and on cell proliferation were determined. Drug effects on apoptosis were investigated using Annexin V staining and a cell death ELISA assay. Effects of the drugs on AR ligand-binding activity and on AR protein levels were determined. RESULTS Dutasteride inhibited (3)H-T conversion to (3)H-DHT and, as anticipated, inhibited T-induced secretion of PSA and proliferation. However the drug also inhibited DHT-induced PSA secretion and cell proliferation (IC(50) approximately 1 microM). Finasteride also inhibited DHT action but was less potent than dutasteride. Dutasteride competed for binding the LNCaP cell AR with an IC(50) approximately 1.5 microM. High concentrations of dutasteride (10-50 microM), but not finasteride, in steroid-free medium, resulted in enhanced cell death, possibly by apoptosis. This was accompanied by loss of AR protein and decreased AR ligand-binding activity. Occupation of AR by R1881 partly protected against cell death and loss of AR protein. PC-3 prostate cancer cells, which do not contain AR, also were killed by high concentrations of dutasteride, as well as by 50 microM finasteride. CONCLUSIONS Dutasteride exhibited some inhibitory actions in LNCaP cells possibly related to 5alphaR inhibition but also had antiandrogenic effects at relatively low concentrations and cell death-promoting effects at higher concentrations. Finasteride also was antiandrogenic, but less than dutasteride. The antiandrogenic effects may be mediated by the mutant LNCaP cell AR. Promotion of cell death by dutasteride can be blocked, but only in part, by androgens.
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Affiliation(s)
- C B Lazier
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.
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Khisti RT, Penland SN, VanDoren MJ, Grobin AC, Morrow AL. GABAergic neurosteroid modulation of ethanol actions. World J Biol Psychiatry 2002; 3:87-95. [PMID: 12479081 DOI: 10.3109/15622970209150606] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Systemic administration of ethanol elevates plasma and cerebral cortical GABAergic neuroactive steroids. The increase in neurosteroids is responsible for specific behavioural and electrophysiological actions of ethanol in rodents. This article recapitulates the current knowledge of the novel interaction between ethanol and neurosteroids and addresses the potential mechanism for ethanol-induced increase in brain neurosteroid levels. Ethanol-induced increase in the cortical neurosteroid content is modified by neurosteroid biosynthesis inhibitors and completely prevented by adrenalectomy in male rats. In line with this, adrenalectomy prevented the anticonvulsant and hypnotic effects of acute ethanol administration. It is speculated that acute ethanol administration might resemble acute stress and increase neuroactive steroids due to activation of hypothalamic-pituitary adrenal axis. Ethanol-induced increases in neuroactive steroids might be responsible for the antidepressant, anxiolytic, spatial learning deficits and drug discriminatory actions in rodents. Thus ethanol-induced increases in neuroactive steroids represent a novel mechanism of ethanol's action, responsible for several pharmacological and behavioural actions of ethanol. The development of new therapeutic strategies for alcoholism may arise based on the novel interaction between ethanol and neurosteroids in the brain.
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Affiliation(s)
- Rahul T Khisti
- Departments of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, CB#7178, 3027 Thurston Bowles Bldg., University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7178, USA
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Tian G, Haffner CD. Linear relationships between the ligand binding energy and the activation energy of time-dependent inhibition of steroid 5alpha-reductase by delta 1-4-azasteroids. J Biol Chem 2001; 276:21359-64. [PMID: 11279132 DOI: 10.1074/jbc.m100793200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The inhibition of steroid 5alpha-reductase (5AR) by Delta(1)-4-azasteroids is characterized by a two-step time-dependent kinetic mechanism where inhibitor combines with enzyme in a fast equilibrium, defined by the inhibition constant K(i), to form an initial reversible enzyme-inhibitor complex, which subsequently undergoes a time-dependent chemical rearrangement, defined by the rate constant k(3), leading to the formation of an apparently irreversible, tight-binding enzyme-inhibitor complex (Tian, G., Mook, R. A., Jr., Moss, M. L., and Frye, S. V. (1995) Biochemistry 34, 13453-13459). A detailed kinetic analysis of this process with a series of Delta(1)-4-azasteroids having different C-17 substituents was performed to understand the relationships between the rate of time-dependent inhibition and the affinity of the time-dependent inhibitors for the enzyme. A linear correlation was observed between ln(1/K(i)), which is proportional to the ligand binding energy for the formation of the enzyme-inhibitor complex, and ln(1/(k(3)/K(i))), which is proportional to the activation energy for the inhibition reaction under the second order reaction condition, which leads to the formation of the irreversible, tight-binding enzyme-inhibitor complex. The coefficient of the correlation was -0.88 +/- 0.07 for type 1 5AR and -1.0 +/- 0.2 for type 2 5AR. In comparison, there was no obvious correlation between ln(1/K(i)) and ln(1/k(3)), which is proportional to the activation energy of the second, time-dependent step of the inhibition reaction. These data are consistent with a model where ligand binding energies provided at C-17 of Delta(1)-4-azasteroids is fully expressed to lower the activation energy of k(3)/K(i) with little perturbation of the energy barrier of the second, time-dependent step.
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Affiliation(s)
- G Tian
- Departments of Molecular Biochemistry, GlaxoSmithKline Research and Development, Research Triangle Park, North Carolina 27709, USA.
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SPAN PAULN, VOLLER MAUREENC, SMALS ANTHONYG, SWEEP FREDG, SCHALKEN JACKA, FENELEY MARKR, KIRBY ROGERS. SELECTIVITY OF FINASTERIDE AS AN IN VIVO INHIBITOR OF 5 alpha-REDUCTASE ISOZYME ENZYMATIC ACTIVITY IN THE HUMAN PROSTATE. J Urol 1999. [DOI: 10.1016/s0022-5347(01)62141-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- PAUL N. SPAN
- Department of Internal Medicine, Division of Endocrinology, the Department of Chemical Endocrinology, and the Urological Research Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands, the Department of Urology, St. Bartholomew's Hospital, and the Department of Urology, St. George's Hospital, London, United Kingdom
| | - MAUREEN C.W. VOLLER
- Department of Internal Medicine, Division of Endocrinology, the Department of Chemical Endocrinology, and the Urological Research Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands, the Department of Urology, St. Bartholomew's Hospital, and the Department of Urology, St. George's Hospital, London, United Kingdom
| | - ANTHONY G.H. SMALS
- Department of Internal Medicine, Division of Endocrinology, the Department of Chemical Endocrinology, and the Urological Research Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands, the Department of Urology, St. Bartholomew's Hospital, and the Department of Urology, St. George's Hospital, London, United Kingdom
| | - FRED G.J. SWEEP
- Department of Internal Medicine, Division of Endocrinology, the Department of Chemical Endocrinology, and the Urological Research Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands, the Department of Urology, St. Bartholomew's Hospital, and the Department of Urology, St. George's Hospital, London, United Kingdom
| | - JACK A. SCHALKEN
- Department of Internal Medicine, Division of Endocrinology, the Department of Chemical Endocrinology, and the Urological Research Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands, the Department of Urology, St. Bartholomew's Hospital, and the Department of Urology, St. George's Hospital, London, United Kingdom
| | - MARK R. FENELEY
- Department of Internal Medicine, Division of Endocrinology, the Department of Chemical Endocrinology, and the Urological Research Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands, the Department of Urology, St. Bartholomew's Hospital, and the Department of Urology, St. George's Hospital, London, United Kingdom
| | - ROGER S. KIRBY
- Department of Internal Medicine, Division of Endocrinology, the Department of Chemical Endocrinology, and the Urological Research Laboratory, University Hospital St. Radboud, Nijmegen, The Netherlands, the Department of Urology, St. Bartholomew's Hospital, and the Department of Urology, St. George's Hospital, London, United Kingdom
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SELECTIVITY OF FINASTERIDE AS AN IN VIVO INHIBITOR OF 5 alpha-REDUCTASE ISOZYME ENZYMATIC ACTIVITY IN THE HUMAN PROSTATE. J Urol 1999. [DOI: 10.1097/00005392-199901000-00100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Frye SV, Bramson HN, Hermann DJ, Lee FW, Sinhababu AK, Tian G. Discovery and development of GG745, a potent inhibitor of both isozymes of 5 alpha-reductase. PHARMACEUTICAL BIOTECHNOLOGY 1998; 11:393-422. [PMID: 9760689 DOI: 10.1007/0-306-47384-4_17] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- S V Frye
- Glaxo Wellcome Research and Development, Research Triangle Park, North Carolina 27709, USA
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Abstract
BACKGROUND The dog has been extensively used as an in vivo model to test the pharmacokinetics and effects on pathological prostatic growth of 5 alpha-reductase inhibitors. However, no information is available on the existence or characteristics of canine 5 alpha-reductase isozymes. METHODS The 5 alpha-reduction of testosterone is analyzed in dog prostatic homogenates. Three human-specific inhibitors are tested for their activity against dog 5 alpha-reductase. RESULTS Two pH optima of 5 alpha-reductase activity in dog prostatic homogenates are described, comparable to the pH optima of rat and human 5 alpha-reductase isozymes. Kinetic analysis of 5 alpha-reductase enzymatic activity at pH 7.0 revealed isozymes with a low apparent affinity constant (Km = 2.67 nM) and a high apparent affinity constant (Km = 1.23 microM). These apparent affinity constants compare favorably to the human and rat isozymes types II and I, respectively. The human type II inhibitor finasteride selectively inhibited the low Km isozyme, whereas the human type I inhibitor MK386 preferentially inhibited the high Km isozyme. The human type I inhibitor LY306089 was nonspecific for the dog isozymes. CONCLUSIONS We postulate that the high and low Km isozymes described here represent the dog type I and type II 5 alpha-reductase isozymes, respectively.
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Affiliation(s)
- P N Span
- Department of Medicine, University Hospital St. Radboud, Nijmegen, The Netherlands.
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Synthesis of a chemiluminescent probe useful for the purification of steroid 5α-reductase. Bioorg Med Chem Lett 1996. [DOI: 10.1016/0960-894x(96)00360-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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