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Gadhave D, Gupta A, Khot S, Tagalpallewar A, Kokare C. Nose-to-brain delivery of paliperidone palmitate poloxamer-guar gum nanogel: Formulation, optimization and pharmacological studies in rats. Ann Pharm Fr 2023; 81:315-333. [PMID: 36037930 DOI: 10.1016/j.pharma.2022.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/01/2022] [Accepted: 08/23/2022] [Indexed: 10/15/2022]
Abstract
Oral delivery of paliperidone palmitate (PPD), a potent antipsychotic agent, has been reported with a potential risk of very serious drug-induced adverse events such as tachycardia, hyperprolactinemia, sexual dysfunction, and neutropenia. Alternatively, the potential of nasal delivery has also been explored to treat CNS complications by delivering the medicines directly to the brain bypassing the blood-brain barrier. Hence, the objectives of current work were to formulate, design, optimize, and investigate the therapeutic potency of PPD-loaded intranasal in-situ gel (PPGISG) in the treatment of schizophrenia. PPD-nanoemulsion (PNE) was fabricated using water titration technique, was further optimized via Box-Behnken design. Furthermore, the optimized PNE was evaluated for parameters such as globule size, polydispersity index, zeta potential, and % entrapment efficiency were found to be 21.44±1.58nm, 0.268±0.02, -25.56±1.6mV, and 99.89±0.25%, respectively. PNE was further converted to PPGISG utilizing two polymers, poloxamer, and guar gum. Simultaneously, ex-vivo permeation for PNE, PPGISG, and PPD-suspension was found to be 211.40±4.8, 297.89±3.9 and 98.66±1.6μg/cm2, respectively. While PPGISG nanoparticles showed 1.58 and 5.65-folds more Jss than PNE and PPD-suspension. Behavioral studies confirmed that no extrapyramidal symptoms were observed in experimental animals post intranasal administration. Finally, the outcomes of the in-vivo hemato-compatibility study proved that intranasal formulation did not cause any alteration in leukocytes, RBCs, and neutrophils count. Therefore, intranasal delivery of PPGISG can be considered a novel tool for the safe delivery of PPD in schizophrenic patients.
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Affiliation(s)
- D Gadhave
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India; Department of Pharmaceutics, Dattakala Shikshan Sanstha's, Dattakala College of Pharmacy (Affiliated to Savitribai Phule Pune University), Swami Chincholi, Daund, Pune, 413130, Maharashtra, India.
| | - A Gupta
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India
| | - S Khot
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India
| | - A Tagalpallewar
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India; School of Pharmacy, Department of Pharmaceutics, MIT World Peace University, Pune, 411038, Maharashtra, India
| | - C Kokare
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India
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Gadhave D, Tupe S, Tagalpallewar A, Gorain B, Choudhury H, Kokare C. Nose-to-brain delivery of amisulpride-loaded lipid-based poloxamer-gellan gum nanoemulgel: In vitro and in vivo pharmacological studies. Int J Pharm 2021; 607:121050. [PMID: 34454028 DOI: 10.1016/j.ijpharm.2021.121050] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 07/16/2021] [Accepted: 08/23/2021] [Indexed: 12/22/2022]
Abstract
Unfavorable side effects of available antipsychotics limit the use of conventional delivery systems, where limited exposure of the drugs to the systemic circulation could reduce the associated risks. The potential of intranasal delivery is gaining interest to treat brain disorders by delivering the drugs directly to the brain circumventing the tight junctions of the blood-brain barrier with limited systemic exposure of the entrapped therapeutic. Therefore, the present research was aimed to fabricate, optimize and investigate the therapeutic efficacy of amisulpride (AMS)-loaded intranasal in situ nanoemulgel (AMS-NG) in the treatment of schizophrenia. In this context, AMS nanoemulsion (AMS-NE) was prepared by employing aqueous-titration method and optimized using Box-Behnken statistical design. The optimized nanoemulsion was subjected to evaluation of globule size, transmittance, zeta potential, and mucoadhesive strength, which were found to be 92.15 nm, 99.57%, -18.22 mV, and 8.90 g, respectively. The AMS-NE was converted to AMS-NG using poloxamer 407 and gellan gum. Following pharmacokinetic evaluation in Wistar rats, the brain Cmax for intranasal AMS-NG was found to be 1.48-folds and 3.39-folds higher when compared to intranasal AMS-NE and intravenous AMS-NE, respectively. Moreover, behavioral investigations of developed formulations were devoid of any extrapyramidal side effects in the experimental model. Finally, outcomes of the in vivo hematological study confirmed that intranasal administration of formulation for 28 days did not alter leukocytes and agranulocytes count. In conclusion, the promising results of the developed and optimized intranasal AMS-NG could provide a novel platform for the effective and safe delivery of AMS in schizophrenic patients.
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Affiliation(s)
- Dnyandev Gadhave
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India; Department of Pharmaceutics, HSBPVTS, GOI, College of Pharmacy (Affiliated to Savitribai Phule Pune University), Kashti, Ahmednagar 414701, Maharashtra, India
| | - Shrikant Tupe
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India
| | - Amol Tagalpallewar
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India; School of Pharmacy, Department of Pharmaceutics, MIT World Peace University, Pune 411038, Maharashtra, India
| | - Bapi Gorain
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Selangor 47500, Malaysia.
| | - Hira Choudhury
- Department of Pharmaceutical Technology, School of Pharmacy, International Medical University, 57000 Kuala Lumpur, Malaysia
| | - Chandrakant Kokare
- Department of Pharmaceutics, Sinhgad Technical Education Society's, Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India.
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Kumbhar SA, Kokare CR, Shrivastava B, Gorain B, Choudhury H. Antipsychotic Potential and Safety Profile of TPGS-Based Mucoadhesive Aripiprazole Nanoemulsion: Development and Optimization for Nose-To-Brain Delivery. J Pharm Sci 2021; 110:1761-1778. [PMID: 33515583 DOI: 10.1016/j.xphs.2021.01.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/12/2021] [Accepted: 01/19/2021] [Indexed: 12/14/2022]
Abstract
Delivering therapeutics to the brain using conventional dosage forms is always a challenge, thus the present study was aimed to formulate mucoadhesive nanoemulsion (MNE) of aripiprazole (ARP) for intranasal delivery to transport the drug directly to the brain. Therefore, a TPGS based ARP-MNE was formulated and optimized using the Box-Behnken statistical design. The improved in vitro release profile of the formulation was in agreement to enhanced ex vivo permeation through sheep mucous membranes with a maximum rate of permeation co-efficient (62.87 cm h-1 × 103) and flux (31.43 μg cm-2.h-1). The pharmacokinetic profile following single-dose administration showed the maximum concentration of drug in the brain (Cmax) of 15.19 ± 2.51 μg mL-1 and Tmax of 1 h in animals with ARP-MNE as compared to 10.57 ± 1.88 μg mL-1 and 1 h, and 2.52 ± 0.38 μg mL-1 and 3 h upon intranasal and intravenous administration of ARP-NE, respectively. Further, higher values of % drug targeting efficiency (96.9%) and % drug targeting potential (89.73%) of ARP-MNE through intranasal administration were investigated. The studies in Wistar rats showed no existence of extrapyramidal symptoms through the catalepsy test and forelimb retraction results. No ex vivo ciliotoxicity on nasal mucosa reflects the safety of the components and delivery tool. Further, findings on locomotor activity and hind-limb retraction test in ARP-MNE treated animals established its antipsychotic efficacy. Thus, it can be inferred that the developed ARP-MNE could effectively be explored as brain delivery cargo in the effective treatment of schizophrenia without producing any toxic manifestation.
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Affiliation(s)
- Santosh Ashok Kumbhar
- School of Pharmaceutical Sciences, Jaipur National University, Jaipur 302 017, Rajasthan, India; Department of Pharmaceutics, STES's Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411 041, Maharashtra, India
| | - Chandrakant R Kokare
- Department of Pharmaceutics, STES's Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411 041, Maharashtra, India
| | - Birendra Shrivastava
- School of Pharmaceutical Sciences, Jaipur National University, Jaipur 302 017, Rajasthan, India.
| | - Bapi Gorain
- School of Pharmacy, Faculty of Health and Medical Science, Taylor's University, Subang Jaya, Selangor, Malaysia; Centre for Drug Delivery and Molecular Pharmacology, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Selangor, Malaysia
| | - Hira Choudhury
- Department of Pharmaceutical Technology, School of Pharmacy, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia; Centre for Bioactive Molecules and Drug Delivery, Institute for Research, Development and Innovation, International Medical University, Bukit jalil, 57000 Kuala Lumpur, Malaysia.
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Kumbhar SA, Kokare CR, Shrivastava B, Gorain B, Choudhury H. Preparation, characterization, and optimization of asenapine maleate mucoadhesive nanoemulsion using Box-Behnken design: In vitro and in vivo studies for brain targeting. Int J Pharm 2020; 586:119499. [PMID: 32505580 DOI: 10.1016/j.ijpharm.2020.119499] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/04/2020] [Accepted: 05/31/2020] [Indexed: 01/01/2023]
Abstract
The tight junctions between capillary endothelial cells of the blood-brain barrier (BBB) restricts the entry of therapeutics into the brain. Potential of the intranasal delivery tool has been explored in administering the therapeutics directly to the brain, thus bypassing BBB. The objective of this study was to develop and optimize an intranasal mucoadhesive nanoemulsion (MNE) of asenapine maleate (ASP) in order to enhance the nasomucosal adhesion and direct brain targetability for improved efficacy and safety. Box-Behnken statistical design was used to recognize the crucial formulation variables influencing droplet size, size distribution and surface charge of ASP-NE. ASP-MNE was obtained by incorporating GRAS mucoadhesive polymer, Carbopol 971 in the optimized NE. Optimized ASP-MNE displayed spherical morphology with a droplet size of 21.2 ± 0.15 nm and 0.355 polydispersity index. Improved ex-vivo permeation was observed in ASP-NE and ASP-MNE, compared to the ASP-solution. Finally, the optimized formulation was found to be safe in ex-vivo ciliotoxicity study on sheep nasal mucosa. The single-dose pharmacokinetic study in male Wistar rats revealed a significant increase in concentration of ASP in the brain upon intranasal administration of ASP-MNE, with a maximum of 284.33 ± 5.5 ng/mL. The time required to reach maximum brain concentration (1 h) was reduced compared to intravenous administration of ASP-NE (3 h). Furthermore, it has been established during the course of present study, that the brain targeting capability of ASP via intranasal administration had enhanced drug-targeting efficiency and drug-targeting potential. In the animal behavioral studies, no extrapyramidal symptoms were observed after intranasal administration of ASP-MNE, while good locomotor activity and hind-limb retraction test established its antipsychotic activity in treated animals. Thus, it can be concluded that the developed intranasal ASP-MNE could be used as an effective and safe tool for brain targeting of ASP in the treatment of psychotic disorders.
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Affiliation(s)
- Santosh Ashok Kumbhar
- School of Pharmaceutical Sciences, Jaipur National University, Jaipur 302017, Rajasthan, India; Department of Pharmaceutics, STES's Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India
| | - Chandrakant R Kokare
- Department of Pharmaceutics, STES's Sinhgad Institute of Pharmacy (Affiliated to Savitribai Phule Pune University), Narhe, Pune 411041, Maharashtra, India
| | - Birendra Shrivastava
- School of Pharmaceutical Sciences, Jaipur National University, Jaipur 302017, Rajasthan, India.
| | - Bapi Gorain
- School of Pharmacy, Faculty of Health and Medical Science, Taylor's University, 47500 Subang Jaya, Selangor, Malaysia
| | - Hira Choudhury
- Department of Pharmaceutical Technology, School of Pharmacy, International Medical University, 57000 Kuala Lumpur, Malaysia.
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Takahashi S, Okamura A, Yamazaki M, Ni K. ASP2905, a specific inhibitor of the potassium channel Kv12.2 encoded by the Kcnh3 gene, is psychoactive in mice. Behav Brain Res 2020; 378:112315. [PMID: 31654662 DOI: 10.1016/j.bbr.2019.112315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 11/30/2022]
Abstract
Schizophrenia is a major psychiatric disorder associated with positive and negative symptoms and cognitive impairments. In this study, we used animal models of behavior to evaluate the antipsychotic activity of ASP2905, a potent and selective inhibitor of the potassium channel Kv12.2 encoded by the Kcnh3/BEC1 gene. ASP2905 inhibited hyperlocomotion induced by methamphetamine and by phencyclidine. In contrast, ASP2905 did not affect spontaneous locomotion, suggesting that ASP2905 selectively inhibits abnormal behaviors induced by stimulants. Chronic infusion of ASP2905 significantly ameliorated phencyclidine-induced prolongation of immobility time in mice subjected to the forced swimming test. These findings suggest that ASP2905 potentially mitigates symptoms of schizophrenia, such as apathy. The antipsychotic clozapine also reversed phencyclidine-induced prolonged immobility, while risperidone and haloperidol had no effect. Assessment of the effects of ASP2905 on latent learning deficits in mice treated with phencyclidine as neonates subjected to the water-finding task showed that ASP2905 significantly ameliorated phencyclidine-induced prolongation of finding latency, which reflects latent learning performance. These findings suggest that ASP2905 potentially mitigates cognitive impairments caused by schizophrenia, such as attention deficits. In contrast, administration of clozapine did not ameliorate phencyclidine-induced prolongation of finding latency. Therefore, ASP2905 may alleviate the broad spectrum of symptoms of schizophrenia, including positive and negative symptoms and cognitive impairments, which is in contrast to currently available antipsychotics, which are generally only partially effective for ameliorating these symptoms.
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Affiliation(s)
- Shinji Takahashi
- Drug Discovery Research, Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki 305-8585, Japan.
| | - Ai Okamura
- Drug Discovery Research, Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki 305-8585, Japan.
| | - Mayako Yamazaki
- Drug Discovery Research, Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki 305-8585, Japan.
| | - Keni Ni
- Drug Discovery Research, Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki 305-8585, Japan.
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Malik M, Rangel-Barajas C, Mach RH, Luedtke RR. The effect of the sigma-1 receptor selective compound LS-1-137 on the DOI-induced head twitch response in mice. Pharmacol Biochem Behav 2016; 148:136-44. [PMID: 27397487 DOI: 10.1016/j.pbb.2016.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/17/2016] [Accepted: 07/06/2016] [Indexed: 11/24/2022]
Abstract
Several receptor mediated pathways have been shown to modulate the murine head twitch response (HTR). However, the role of sigma receptors in the murine (±)-2,5-dimethoxy-4-iodoamphetamine (DOI)-induced HTR has not been previously investigated. We examined the ability of LS-1-137, a novel sigma-1 vs. sigma-2 receptor selective phenylacetamide, to modulate the DOI-induced HTR in DBA/2J mice. We also assessed the in vivo efficacy of reference sigma-1 receptor antagonists and agonists PRE-084 and PPCC. The effect of the sigma-2 receptor selective antagonist RHM-1-86 was also examined. Rotarod analysis was performed to monitor motor coordination after LS-1-137 administration. Radioligand binding techniques were used to determine the affinity of LS-1-137 at 5-HT2A and 5-HT2C receptors. LS-1-137 and the sigma-1 receptor antagonists haloperidol and BD 1047 were able to attenuate a DOI-induced HTR, indicating that LS-1-137 was acting in vivo as a sigma-1 receptor antagonist. LS-1-137 did not compromise rotarod performance within a dose range capable of attenuating the effects of DOI. Radioligand binding studies indicate that LS-1-137 exhibits low affinity binding at both 5-HT2A and 5-HT2C receptors. Based upon the results from these and our previous studies, LS-1-137 is a neuroprotective agent that attenuates the murine DOI-induced HTR independent of activity at 5-HT2 receptor subtypes, D2-like dopamine receptors, sigma-2 receptors and NMDA receptors. LS-1-137 appears to act as a sigma-1 receptor antagonist to inhibit the DOI-induced HTR. Therefore, the DOI-induced HTR can be used to assess the in vivo efficacy of sigma-1 receptor selective compounds.
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Affiliation(s)
- Maninder Malik
- University of North Texas Health Science Center, The Center for Neuroscience Discovery, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, United States
| | - Claudia Rangel-Barajas
- University of North Texas Health Science Center, The Center for Neuroscience Discovery, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, United States
| | - Robert H Mach
- Radiochemistry Laboratory, Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, United States
| | - Robert R Luedtke
- University of North Texas Health Science Center, The Center for Neuroscience Discovery, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, United States.
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Raheem IT, Schreier JD, Fuerst J, Gantert L, Hostetler ED, Huszar S, Joshi A, Kandebo M, Kim SH, Li J, Ma B, McGaughey G, Sharma S, Shipe WD, Uslaner J, Vandeveer GH, Yan Y, Renger JJ, Smith SM, Coleman PJ, Cox CD. Discovery of pyrazolopyrimidine phosphodiesterase 10A inhibitors for the treatment of schizophrenia. Bioorg Med Chem Lett 2015; 26:126-32. [PMID: 26602277 DOI: 10.1016/j.bmcl.2015.11.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 11/05/2015] [Indexed: 01/23/2023]
Abstract
Herein, we present the identification of a novel class of pyrazolopyrimidine phosphodiesterase 10A (PDE10A) inhibitors. Beginning with a lead molecule (1) identified through a fragment-based drug discovery (FBDD) effort, lead optimization was enabled by rational design, X-ray crystallography, metabolic and off-target profiling, and fragment scaffold-hopping. We highlight the discovery of PyP-1, a potent, highly selective, and orally bioavailable pyrazolopyrimidine inhibitor of PDE10A. PyP-1 exhibits sub-nanomolar potency (PDE10A Ki=0.23nM), excellent pharmacokinetic (PK) and physicochemical properties, and a clean off-target profile. It displays dose-dependent efficacy in numerous pharmacodynamic (PD) assays that measure potential for anti-psychotic activity and cognitive improvement. PyP-1 also has a clean preclinical profile with respect to cataleptic potential in rats, prolactin secretion, and weight gain, common adverse events associated with currently marketed therapeutics. Further, PyP-1 displays in vivo preclinical target engagement as measured by PET enzyme occupancy in concert with [(11)C]MK-8193, a novel PDE10A PET tracer.
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Affiliation(s)
- Izzat T Raheem
- Discovery Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - John D Schreier
- Discovery Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - Joy Fuerst
- Basic Pharmaceutical Sciences, Merck Research Laboratories, West Point, PA 19486, United States
| | - Liza Gantert
- Imaging, Merck Research Laboratories, West Point, PA 19486, United States
| | - Eric D Hostetler
- Imaging, Merck Research Laboratories, West Point, PA 19486, United States
| | - Sarah Huszar
- In Vivo Pharmacology, Merck Research Laboratories, West Point, PA 19486, United States
| | - Aniket Joshi
- Imaging, Merck Research Laboratories, West Point, PA 19486, United States
| | - Monika Kandebo
- Neuroscience, Merck Research Laboratories, West Point, PA 19486, United States
| | - Somang H Kim
- Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, Merck Research Laboratories, West Point, PA 19486, United States
| | - Jing Li
- Discovery Process Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - Bennett Ma
- Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, Merck Research Laboratories, West Point, PA 19486, United States
| | - Georgia McGaughey
- Chemistry Modeling and Informatics, Merck Research Laboratories, West Point, PA 19486, United States
| | - Sujata Sharma
- Structural Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - William D Shipe
- Discovery Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - Jason Uslaner
- In Vivo Pharmacology, Merck Research Laboratories, West Point, PA 19486, United States
| | - George H Vandeveer
- Discovery Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - Youwei Yan
- Structural Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - John J Renger
- Neuroscience, Merck Research Laboratories, West Point, PA 19486, United States
| | - Sean M Smith
- Neuroscience, Merck Research Laboratories, West Point, PA 19486, United States
| | - Paul J Coleman
- Discovery Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
| | - Christopher D Cox
- Discovery Chemistry, Merck Research Laboratories, West Point, PA 19486, United States
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8
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Parmentier-Batteur S, Hutson PH, Menzel K, Uslaner JM, Mattson BA, O'Brien JA, Magliaro BC, Forest T, Stump CA, Tynebor RM, Anthony NJ, Tucker TJ, Zhang XF, Gomez R, Huszar SL, Lambeng N, Fauré H, Le Poul E, Poli S, Rosahl TW, Rocher JP, Hargreaves R, Williams TM. Mechanism based neurotoxicity of mGlu5 positive allosteric modulators--development challenges for a promising novel antipsychotic target. Neuropharmacology 2013; 82:161-73. [PMID: 23291536 DOI: 10.1016/j.neuropharm.2012.12.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 12/06/2012] [Accepted: 12/11/2012] [Indexed: 11/17/2022]
Abstract
Previous work has suggested that activation of mGlu5 receptor augments NMDA receptor function and thereby may constitute a rational approach addressing glutamate hypofunction in schizophrenia and a target for novel antipsychotic drug development. Here, we report the in vitro activity, in vivo efficacy and safety profile of 5PAM523 (4-Fluorophenyl){(2R,5S)-5-[5-(5-fluoropyridin-2-yl)-1,2,4-oxadiazol-3-yl]-2-methylpiperidin-1-yl}methanone), a structurally novel positive allosteric modulator selective of mGlu5. In cells expressing human mGlu5 receptor, 5PAM523 potentiated threshold responses to glutamate in fluorometric calcium assays, but does not have any intrinsic agonist activity. 5PAM523 acts as an allosteric modulator as suggested by the binding studies showing that 5PAM523 did not displace the binding of the orthosteric ligand quisqualic acid, but did partially compete with the negative allosteric modulator, MPyEP. In vivo, 5PAM523 reversed amphetamine-induced locomotor activity in rats. Therefore, both the in vitro and in vivo data demonstrate that 5PAM523 acts as a selective mGlu5 PAM and exhibits anti-psychotic like activity. To study the potential for adverse effects and particularly neurotoxicity, brain histopathological exams were performed in rats treated for 4 days with 5PAM523 or vehicle. The brain exam revealed moderate to severe neuronal necrosis in the rats treated with the doses of 30 and 50 mg/kg, particularly in the auditory cortex and hippocampus. To investigate whether this neurotoxicity is mechanism specific to 5PAM523, similar safety studies were carried out with three other structurally distinct selective mGlu5 PAMs. Results revealed a comparable pattern of neuronal cell death. Finally, 5PAM523 was tested in mGlu5 knock-out (KO) and wild type (WT) mice. mGlu5 WT mice treated with 5PAM523 for 4 days at 100 mg/kg presented significant neuronal death in the auditory cortex and hippocampus. Conversely, mGlu5 KO mice did not show any neuronal loss by histopathology, suggesting that enhancement of mGlu5 function is responsible for the toxicity of 5PAM523. This study reveals for the first time that augmentation of mGlu5 function with selective allosteric modulators results in neurotoxicity.
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Affiliation(s)
| | - Peter H Hutson
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Karsten Menzel
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Jason M Uslaner
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Britta A Mattson
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Julie A O'Brien
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Brian C Magliaro
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Thomas Forest
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Craig A Stump
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Robert M Tynebor
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Neville J Anthony
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Thomas J Tucker
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Xu-Fang Zhang
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Robert Gomez
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Sarah L Huszar
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Nathalie Lambeng
- Addex Therapeutics, 12, chemin des Aulx, 1228 Plan-les-Ouates, Geneva, Switzerland
| | - H Fauré
- Addex Therapeutics, 12, chemin des Aulx, 1228 Plan-les-Ouates, Geneva, Switzerland
| | - Emannuel Le Poul
- Addex Therapeutics, 12, chemin des Aulx, 1228 Plan-les-Ouates, Geneva, Switzerland
| | - Sonia Poli
- Addex Therapeutics, 12, chemin des Aulx, 1228 Plan-les-Ouates, Geneva, Switzerland
| | - Thomas W Rosahl
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Jean-Philippe Rocher
- Addex Therapeutics, 12, chemin des Aulx, 1228 Plan-les-Ouates, Geneva, Switzerland
| | - Richard Hargreaves
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
| | - Theresa M Williams
- Merck Research Laboratories, 770 Sumneytown Pike, West Point, PA 19486-0004, USA
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