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Sharma R, Upadhyaya K, Gupta B, Ghosh KK, Tripathi RP, Musilek K, Kuca K. Glycosylated-imidazole aldoximes as reactivators of pesticides inhibited AChE: Synthesis and in-vitro reactivation study. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2020; 80:103454. [PMID: 32645360 DOI: 10.1016/j.etap.2020.103454] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 06/11/2023]
Abstract
The present armamentarium of commercially available antidotes provides limited protection against the neurological effects of organophosphate exposure. Hence, there is an urgent need to design and develop molecules that can protect and reactivate inhibited-AChE in the central nervous system. Some natural compounds like glucose and certain amino acids (glutamate, the anion of glutamic acid) can easily cross the blood brain barrier although they are highly polar. Glucose is mainly transported by systems like glucose transporter protein type 1 (GLUT1). For this reason, a series of non-quaternary and quaternary glycosylated imidazolium oximes with different alkane linkers have been designed and synthesized. These compounds were evaluated for their in-vitro reactivation ability against pesticide (paraoxon-ethyl and paraoxon-methyl) inhibited-AChE and compared with standards antidote AChE reactivators pralidoxime and obidoxime. Several physicochemical properties including acid dissociation constant (pKa), logP, logD, HBD and HBA, have also been assessed for reported compounds. Out of the synthesized compounds, three have exhibited comparable potency with a standard antidote (pralidoxime).
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Affiliation(s)
- Rahul Sharma
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, CG 492010, India; Department of Plant Physiology, Agril. Biochemistry, Medicinal & Aromatic Plants, Indira Gandhi Agricultural University, Raipur, CG 492005, India
| | - Kapil Upadhyaya
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 West Green Street, Athens, GA 30602, USA
| | - Bhanushree Gupta
- Centre for Basic Sciences, Pt. Ravishankar Shukla University, Raipur CG 492010, India.
| | - Kallol K Ghosh
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, CG 492010, India
| | - Rama P Tripathi
- National Institute of Pharmaceutical Education and Research-Raebareli, Sarojini Nagar, Lucknow, Uttar Pradesh 226301, India
| | - Kamil Musilek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, Hradec Kralove, Czech Republic; University Hospital, Biomedical Research Center, Sokolska 581, 50005, Hradec Kralove, Czech Republic.
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Sakurada K, Ohta H. No promising antidote 25 years after the Tokyo subway sarin attack: A review. Leg Med (Tokyo) 2020; 47:101761. [DOI: 10.1016/j.legalmed.2020.101761] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/26/2020] [Accepted: 07/10/2020] [Indexed: 10/23/2022]
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3
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Chambers JE, Dail MB, Meek EC. Oxime-mediated reactivation of organophosphate-inhibited acetylcholinesterase with emphasis on centrally-active oximes. Neuropharmacology 2020; 175:108201. [PMID: 32544483 DOI: 10.1016/j.neuropharm.2020.108201] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/02/2020] [Accepted: 06/11/2020] [Indexed: 01/25/2023]
Abstract
This review provides an overview of the global research leading to the large number of compounds developed as reactivators of acetylcholinesterase inhibited by a variety of organophosphate compounds, most of which are nerve agents but also some insecticides. A number of these organophosphates are highly toxic and effective therapy by reactivators contributes to saving lives. Two major challenges for more effective therapy with reactivators are identification of a broad spectrum reactivator efficacious against a variety of organophosphate structures, and a reactivator that can cross the blood-brain barrier to protect the brain. The most effective of the reactivators developed are the nucleophilic pyridinium oximes, which bear a permanent positive charge from the quaternary nitrogen in the pyridinium ring. The permanent positive charge retards the oximes from crossing the blood-brain barrier and therefore restoration of normal cholinergic function in the brain is unlikely. A number of laboratories have developed nucleophiles, mostly oximes, that are theorized to cross the blood-brain barrier by several strategies. At the present time, no reactivator is optimally broad spectrum across the wide group of organophosphate chemistries. Some oximes, including the substituted phenoxyalkyl pyridinium oximes invented by our laboratories, have the potential to provide neuroprotection in the brain and show evidence of efficacy against both nerve agent and insecticidal chemistries, so these novel oximes have promise for future development. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Janice E Chambers
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, 39762-6100, USA.
| | - Mary B Dail
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, 39762-6100, USA
| | - Edward C Meek
- Center for Environmental Health Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, 39762-6100, USA
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Katz FS, Pecic S, Schneider L, Zhu Z, Hastings-Robinson A, Luzac M, Macdonald J, Landry DW, Stojanovic MN. New therapeutic approaches and novel alternatives for organophosphate toxicity. Toxicol Lett 2018; 291:1-10. [PMID: 29614332 DOI: 10.1016/j.toxlet.2018.03.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/18/2018] [Accepted: 03/26/2018] [Indexed: 10/17/2022]
Abstract
Organophosphate compounds (OPCs) are commonly used as pesticides and were developed as nerve agents for chemical warfare. Exposure to OPCs results in toxicity due to their covalent binding and inhibition of acetylcholinesterase (AChE). Treatment for toxicity due to OPC exposure has been largely focused on the reactivation of AChE by oxime-based compounds via direct nucleophilic attack on the phosphorous center. However, due to the disadvantages to existing oxime-based reactivators for treatment of OPC poisoning, we considered non-oxime mechanisms of reactivation. A high throughput screen of compound libraries was performed to discover previously unidentified reactivation compounds, followed by studies on their analogs. In the process, we discovered multiple non-oxime classes of compounds, the most robust of which we have already reported [1]. Herein, we report other classes of compounds we identified in our screen that are efficient at reactivation. During biochemical characterization, we also found some compounds with other activities that may inspire novel therapeutic approaches to OPC toxicity. Specifically, we found compounds that [1] increase the rate of substrate hydrolysis by AChE and, [2] protect the enzyme from inhibition by OPC. Further, we discovered that a subset of reactivator compounds recover activity from both AChE and the related enzyme butyrylcholinesterase (BuChE). We now report these compounds, their activities and discuss how each relates to therapeutic approaches that would provide alternatives to traditional oxime-based reactivation.
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Affiliation(s)
- Francine S Katz
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA.
| | - Stevan Pecic
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA.
| | - Laura Schneider
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA
| | - Zhengxiang Zhu
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA
| | - Ashley Hastings-Robinson
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA
| | - Michal Luzac
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA
| | - Joanne Macdonald
- Genecology Research Centre, Inflammation and Healing Research Cluster, School of Science and Engineering, University of the Sunshine Coast, 90 Sippy Downs Drive Sippy Downs, QLD 4556, Australia
| | - Donald W Landry
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA
| | - Milan N Stojanovic
- Department of Medicine, Columbia University, 630 W 168th Street, BB8-444, New York, NY, 10032, USA
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Buchwald P, Bodor N. Brain-Targeting Chemical Delivery Systems and Their Cyclodextrin-Based Formulations in Light of the Contributions of Marcus E. Brewster. J Pharm Sci 2016; 105:2589-2600. [DOI: 10.1016/j.xphs.2016.04.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/07/2016] [Accepted: 04/07/2016] [Indexed: 11/29/2022]
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Swami D, Karade HN, Acharya J, Kumar P. In vivo protection studies of bis-quaternary 2-(hydroxyimino)-N-(pyridin-3-yl) acetamide derivatives against sarin poisoning in mice. Hum Exp Toxicol 2016; 36:23-32. [DOI: 10.1177/0960327116637109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In vivo antidotal efficacy of new bis- quaternary 2-(hydroxyimino)- N-(pyridin-3yl) acetamide derivatives (HNK series), to counter multiples of lethal doses of nerve agent sarin (GB) and reactivation of acetylcholinesterase (AChE), was evaluated in Swiss albino mice. [Protection index PI; median lethal dose (LD50) of sarin with treatment/LD50 of sarin] was estimated, using 0.05, 0.10, and 0.20 LD50 as treatment doses of all the oximes with atropine against sarin poisoning. Dose-dependent time course study was conducted at 0.2, 0.4 and 0.8 LD50 dose of sarin for estimating maximum AChE inhibition. At optimized time (15 min), in vivo enzyme half inhibition concentration (IC50) was calculated. AChE reactivation efficacy of HNK series and pralidoxime (2-PAM) were determined by plotting shift of log IC50 doses. HNK-102 with atropine showed three fold higher PI compared to 2-PAM. In vivo IC50 of sarin for brain and serum AChE was found to be 0.87 LD50 (139.2 µg/kg) and 0.48 LD50 (77.23 µg/kg), respectively. Treatment with HNK-102 and HNK-111 (equal to their 0.20LD50) significantly reactivated sarin-intoxicated AChE ( p < 0.05) at 2× IC50 dose of sarin, compared to 2-PAM. The study revealed that HNK-102 oxime was three times more potent as antidote, for acute sarin poisoning compared to 2-PAM in vivo.
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Affiliation(s)
- Devyani Swami
- Pharmacology and Toxicology Division, Defence Research & Development Establishment, Gwalior, India
| | - Hitendra N Karade
- Process Technology Development Division, Defence Research & Development Establishment, Gwalior, India
| | - Jyotiranjan Acharya
- Process Technology Development Division, Defence Research & Development Establishment, Gwalior, India
| | - Pravin Kumar
- Pharmacology and Toxicology Division, Defence Research & Development Establishment, Gwalior, India
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7
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Voicu VA, Medvedovici AV, Sakurada K, Ohta H, Rădulescu FȘ, Miron DS. The forgotten or underestimated relevance of biopharmaceutical-based assessments for the oral absorption studies of oxime reactivators. Expert Opin Drug Metab Toxicol 2016; 12:743-52. [DOI: 10.1080/17425255.2016.1179282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Victor A. Voicu
- Department of Pharmacology, Toxicology and Clinical Psychopharmacology, University of Medicine and Pharmacy ‘Carol Davilla’, Bucharest, Romania
- Medical Science Section, Romanian Academy, Bucharest, Romania
| | | | - Koichi Sakurada
- Department of Forensic Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hikoto Ohta
- Department of Forensic Chemistry, Toxicology Section, National Research Institute of Police Science, National Police Agency, Kashiwa City, Chiba, Japan
| | | | - Dalia Simona Miron
- Faculty of Pharmacy, University of Medicine and Pharmacy Carol Davila, Bucharest, Romania
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Jansone B, Kadish I, van Groen T, Beitnere U, Moore DR, Plotniece A, Pajuste K, Klusa V. A Novel 1,4-Dihydropyridine Derivative Improves Spatial Learning and Memory and Modifies Brain Protein Expression in Wild Type and Transgenic APPSweDI Mice. PLoS One 2015; 10:e0127686. [PMID: 26042808 PMCID: PMC4456351 DOI: 10.1371/journal.pone.0127686] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 04/17/2015] [Indexed: 11/18/2022] Open
Abstract
Ca2+ blockers, particularly those capable of crossing the blood-brain barrier (BBB), have been suggested as a possible treatment or disease modifying agents for neurodegenerative disorders, e.g., Alzheimer’s disease. The present study investigated the effects of a novel 4-(N-dodecyl) pyridinium group-containing 1,4-dihydropyridine derivative (AP-12) on cognition and synaptic protein expression in the brain. Treatment of AP-12 was investigated in wild type C57BL/6J mice and transgenic Alzheimer’s disease model mice (Tg APPSweDI) using behavioral tests and immunohistochemistry, as well as mass spectrometry to assess the blood-brain barrier (BBB) penetration. The data demonstrated the ability of AP-12 to cross the BBB, improve spatial learning and memory in both mice strains, induce anxiolytic action in transgenic mice, and increase expression of hippocampal and cortical proteins (GAD67, Homer-1) related to synaptic plasticity. The compound AP-12 can be seen as a prototype molecule for use in the design of novel drugs useful to halt progression of clinical symptoms (more specifically, anxiety and decline in memory) of neurodegenerative diseases, particularly Alzheimer’s disease.
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Affiliation(s)
- Baiba Jansone
- Department of Pharmacology, Faculty of Medicine, University of Latvia, Riga, Latvia
- * E-mail:
| | - Inga Kadish
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Thomas van Groen
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Ulrika Beitnere
- Department of Pharmacology, Faculty of Medicine, University of Latvia, Riga, Latvia
| | - Doyle Ray Moore
- Department of Pharmacology/Toxicology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | | | | | - Vija Klusa
- Department of Pharmacology, Faculty of Medicine, University of Latvia, Riga, Latvia
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9
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Bhattacharjee AK, Marek E, Le HT, Ratcliffe R, DeMar JC, Pervitsky D, Gordon RK. Discovery of non-oxime reactivators using an in silico pharmacophore model of reactivators for DFP-inhibited acetylcholinesterase. Eur J Med Chem 2015; 90:209-20. [DOI: 10.1016/j.ejmech.2014.11.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 11/03/2014] [Accepted: 11/05/2014] [Indexed: 10/24/2022]
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10
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Gold nanoparticles: emerging paradigm for targeted drug delivery system. Biotechnol Adv 2012; 31:593-606. [PMID: 23111203 DOI: 10.1016/j.biotechadv.2012.10.002] [Citation(s) in RCA: 206] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 10/07/2012] [Accepted: 10/22/2012] [Indexed: 12/21/2022]
Abstract
The application of nanotechnology in medicine, known as nanomedicine, has introduced a plethora of nanoparticles of variable chemistry and design considerations for cancer diagnosis and treatment. One of the most important field is the design and development of pharmaceutical drugs, based on targeted drug delivery system (TDDS). Being inspired by physio-chemical properties of nanoparticles, TDDS are designed to safely reach their targets and specifically release their cargo at the site of disease for enhanced therapeutic effects, thereby increasing the drug tissue bioavailability. Nanoparticles have the advantage of targeting cancer by simply being accumulated and entrapped in cancer cells. However, even after rapid growth of nanotechnology in nanomedicine, designing an effective targeted drug delivery system is still a challenging task. In this review, we reveal the recent advances in drug delivery approach with a particular focus on gold nanoparticles. We seek to expound on how these nanomaterials communicate in the complex environment to reach the target site, and how to design the effective TDDS for complex environments and simultaneously monitor the toxicity on the basis of designing such delivery complexes. Hence, this review will shed light on the research, opportunities and challenges for engineering nanomaterials with cancer biology and medicine to develop effective TDDS for treatment of cancer.
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11
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Bhonsle JB, Causey R, Oyler BL, Bartolucci C, Lamba D, Pesaresi A, Bhamare NK, Soojhawon I, Garcia GE. Evaluation and computational characterization of the facilitated transport of Glc carbon C-1 oxime reactivators across a blood brain barrier model. Chem Biol Interact 2012; 203:129-34. [PMID: 23073172 DOI: 10.1016/j.cbi.2012.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 09/04/2012] [Accepted: 09/25/2012] [Indexed: 10/27/2022]
Abstract
We are evaluating a facilitative transport strategy to move oximes across the blood brain barrier (BBB) to reactivate inhibited brain acetylcholinesterase (AChE). We selected glucose (Glc) transporters (GLUT) for this purpose as these transporters are highly represented in the BBB. Glc conjugates have successfully moved drugs across the BBB and previous work has shown that Glc-oximes (sugar-oximes, SOxs) can reduce the organophosphonate induced hypothermia response. We previously evaluated the reactivation potential of Glc carbon C-1 SOxs. Here we report the reactivation parameters for VX- and GB-inhibited human (Hu) AChE of the best SOx (13c) and our findings that the kinetics are similar to those of the parent oxime. Although crystals of Torpedo californica AChE were produced, neither soaked or co-crystallized experiments were successful at concentrations below 20mM 13c, and higher concentrations cracked the crystals. 13c was non-toxic to neuroblastoma and kidney cell lines at 12-18 mM, allowing high concentrations to be used in a BBB kidney cell model. The transfer of 13c from the donor side was asymmetric with the greatest loss of 13c from the apical- or luminal-treated side. There was no apparent transfer from the basolateral side. The 13cP(app) results indicate a 'low' transport efficiency; however, mass accounting revealed only a 20% recovery from the apical dose in which high concentrations were found in the cell lysate fraction. Molecular modeling of 13c through the GLUT-1 channel demonstrated that transport of 13c was more restricted than Glc. Selected sites were compared and the 13c binding energies were greater than two times those of Glc.
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Affiliation(s)
- Jayendra B Bhonsle
- Astha Drug Discovery & Research, 5284 Randolph Road #262, Rockville, MD 20852, USA
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12
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Discovery of non-oxime reactivators using an in silico pharmacophore model of oxime reactivators of OP-inhibited acetylcholinesterase. Eur J Med Chem 2012; 49:229-38. [DOI: 10.1016/j.ejmech.2012.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 12/26/2011] [Accepted: 01/07/2012] [Indexed: 11/30/2022]
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13
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Kalisiak J, Ralph EC, Zhang J, Cashman JR. Amidine-oximes: reactivators for organophosphate exposure. J Med Chem 2011; 54:3319-30. [PMID: 21438612 DOI: 10.1021/jm200054r] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new class of amidine-oxime reactivators of organophosphate (OP)-inhibited cholinesterases (ChE) were designed, synthesized, and tested. These compounds represent a novel group of oximes with enhanced capabilities of crossing the blood-brain barrier. Lack of brain penetration is a major limitation for currently used oximes as antidotes of OP poisoning. The concept described herein relies on a combination of an amidine residue and oxime functionality whereby the amidine increases the binding affinity to the ChE and the oxime is responsible for reactivation. Amidine-oximes were tested in vitro and reactivation rates for OP-BuChE were greater than pralidoxime (2-PAM) or monoisonitrosoacetone (MINA). Amidine-oxime reactivation rates for OP-AChE were lower compared to 2-PAM but greater compared with MINA. After pretreatment for 30 min with oximes 15c and 15d (145 μmol/kg, ip) mice were challenged with a soman model compound. In addition, 15d was tested in a post-treatment experiment (145 μmol/kg, ip, administration 5 min after sarin model compound exposure). In both cases, amidine-oximes afforded 100% 24 h survival in an animal model of OP exposure.
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Affiliation(s)
- Jarosław Kalisiak
- Human BioMolecular Research Institute, 5310 Eastgate Mall, San Diego, California 92121, United States.
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Shih TM, Guarisco JA, Myers TM, Kan RK, McDonough JH. The oxime pro-2-PAM provides minimal protection against the CNS effects of the nerve agents sarin, cyclosarin, and VX in guinea pigs. Toxicol Mech Methods 2010; 21:53-62. [DOI: 10.3109/15376516.2010.529190] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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15
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Garcia GE, Campbell AJ, Olson J, Moorad-Doctor D, Morthole VI. Novel oximes as blood-brain barrier penetrating cholinesterase reactivators. Chem Biol Interact 2010; 187:199-206. [PMID: 20227398 DOI: 10.1016/j.cbi.2010.02.033] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 02/17/2010] [Accepted: 02/19/2010] [Indexed: 10/19/2022]
Abstract
The US Army utilizes pralidoxime (2-PAM) for the reactivation of OP-inhibited AChE. While 2-PAM effectively reactivates acetylcholinesterase (AChE) in the body, it does not cross the blood-brain barrier (BBB) at therapeutically relevant levels. To address this problem of central nervous system AChE reactivation, novel sugar-oxime conjugates were utilized. These 'sugar-oximes' would potentially be transported across the BBB because they contain a sugar moiety which would be recognized by the facilitative glucose transporters. Eight previously reported, but understudied sugar-oximes, as well as six novel sugar-oximes were synthesized, and their ability to reactivate both human red blood cell AChE and plasma butyrylcholinesterase poisoned with DFP, paraoxon, sarin and VX were tested. The results show that the novel sugar-oxime 13c was more active than the other compounds with a reactivation potential similar to 2-PAM. The sugar-oxime 8b had low toxicity with a LD(50) of 1,590 mg/kg from a single IM dose in the guinea pig and >2,000 mg/kg IP in the mouse. Histopathological analysis showed that there were no apparent differences in hippocampus, heart, liver, kidney sciatic nerve, or skeletal muscle between treated and untreated animals. These results show that sugar-oximes can be effective reactivators and suggest that high treatment doses may be possible.
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Affiliation(s)
- Gregory E Garcia
- Division of Biochemistry, Walter Reed Army Institute of Research, 503 Forney Ave, Silver Spring, MD 20910-7500, USA.
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Hedayatullah M, Lion C, Tourki A. DéCONTAMINATION CHIMIQUE DU PARAOXON AU MOYEN DE NOUVEAUX NUCLéOPHILES A EFFET-α DéRIVéS DE L'ADAMANTANE. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509208040642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Sakurada K, Matsubara K, Shimizu K, Shiono H, Seto Y, Tsuge K, Yoshino M, Sakai I, Mukoyama H, Takatori T. Pralidoxime iodide (2-pAM) penetrates across the blood-brain barrier. Neurochem Res 2003; 28:1401-7. [PMID: 12938863 DOI: 10.1023/a:1024960819430] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The in vivo rat brain microdialysis technique with HPLC/UV was used to determine the blood-brain barrier (BBB) penetration of pralidoxime iodide (2-PAM), which is a component of the current nerve agent antidote therapy. After intravenous dosage of 2-PAM (10, 50, 100 mg/kg), 2-PAM appeared dose-dependently in the dialysate; the striatal extracellular/blood concentration ratio at 1 h after 50 mg/kg dosage was 0.093 +/- 0.053 (mean +/- SEM). This finding offered conclusive evidence of the BBB penetration of 2-PAM. We also examined whether the BBB penetration of 2-PAM was mediated by a certain specific transporter, such as a neutral or basic amino acid transport system. Although it was unclear, the neural uptake of 2-PAM was Na+ dependent. The mean BBB penetration by 2-PAM was approximately 10%, indicating the intravenous administration of 2-PAM might be to a degree effective to reactivation of the blocked cholinesterase in the brain.
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Affiliation(s)
- Koichi Sakurada
- National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-city, Chiba 277-0880, Japan.
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Abstract
Chemical delivery systems (CDSs) based on the redox conversion of a lipophilic dihydropyridine to an ionic, lipid-insoluble pyridinium salt have been developed to improve the access of therapeutic agents to the central nervous system. A dihydropyridinium-type CDS or a redox analog of the drug is sufficiently lipophilic to enter the brain by passive transport, then undergoes an enzymatic oxidation to an ionic pyridinium compound, which promotes retention in the CNS. At the same time, peripheral elimination of the entity is accelerated due to facile conversion of the CDS in the body. This review discusses chemical, physicochemical, biochemical, and biological aspects in relation to the principles and practical implementation of the redox brain-targeting approach to various classes of drugs. Representative examples to the brain-enhanced delivery of neurotransmitters, steroids, anticonvulsants, antibiotics, antiviral, anticancer and antidementia agents, and neuropeptides and their analogs are presented in detail. In vivo and in vitro studies and preliminary clinical data of several novel derivatives have been promising, which could lead to a practical use of the redox CDSs after proper pharmaceutical development. The investigations accentuate the need for considering physicochemical, metabolic, and pharmacokinetic properties in designing of carrier systems that are able to target drugs into the central nervous system.
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Affiliation(s)
- L Prokai
- Center for Drug Discovery, College of Pharmacy, University of Florida, J. Hillis Miller Health Center, Gainesville, FL 32610, USA.
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Abstract
Prodrugs are pharmacologically inactive chemical derivatives of a drug molecule that require a transformation within the body in order to release the active drug. They are designed to overcome pharmaceutical and/or pharmacokinetically based problems associated with the parent drug molecule that would otherwise limit the clinical usefulness of the drug. The scientific rationale, based on clinical, pharmaceutical and chemical experience, for the design of various currently used prodrugs is presented in this review. The examples presented are by no means comprehensive, but are representative of the different ways in which the prodrug approach has been used to enhance the clinical efficacy of various drug molecules.
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Gray AP. Design and structure-activity relationships of antidotes to organophosphorus anticholinesterase agents. Drug Metab Rev 1984; 15:557-89. [PMID: 6386410 DOI: 10.3109/03602538409029973] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Kenley RA, Howd RA, Uyeno ET. Effects of PAM, proPAM, and DFP on behavior, thermoregulation, and brain AChE in rats. Pharmacol Biochem Behav 1982; 17:1001-8. [PMID: 7178195 DOI: 10.1016/0091-3057(82)90485-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The effects of pyridine-2 aldoxime methyl iodide (PAM), N-methyl-1,6-dihydro-pyridine-2-carbaldoxime hydrochloride (proPAM), and diisopropyl phosphorofluoridate (DFP) on performance of a conditioned avoidance response (CAR), body temperature, and in vivo acetylcholinesterase (AChE) activity in five brain regions in the rat were examined. Sublethal doses of DFP (1.5 to 2.5 mg/kg, IP) markedly degraded CAR performance. This effect was antagonized by 5 mg/kg, subcutaneously injected (SC) atropine. A 50 mg/kg, SC dose of PAM had no effect on the CAR, but an equal dose of proPAM caused a transient deterioration of performance. Given 10 min or 2 hr after DFP, 50 mg/kg proPAM initially exacerbated the behaviorally toxic effects of DFP. Neither PAM nor proPAM antagonized DFP-induced hypothermia. PAM did not reactivate DFP-inhibited brain AChE, and proPAM reactivated it by only 6 to 12% of control activity.
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Abstract
A dihydropyridine-pyridinium salt type of redox system is used in a general and flexible method for the site-specific or sustained delivery (or both) of drugs to the brain. A biologically active compound linked to a lipoidal dihydropyridine carrier easily penetrates the blood-brain barrier. Oxidation of the carrier part in vivo to the ionic pyridinium salt prevents its elimination from the brain, while elimination from the general circulation is accelerated. Subsequent cleavage of the quaternary carrier-drug species results in sustained delivery of the drug in the brain and facile elimination of the carrier part.
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Bajgar J, Fusek J, Patocka J, Hrdina V. Continual monitoring of the reactivation effect of oximes on blood acetylcholinesterase in the rats poisoned with organophosphates. Toxicology 1981; 21:71-5. [PMID: 7281197 DOI: 10.1016/0300-483x(81)90017-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Acetylcholinesterase activity in rat blood was continuously monitored following O-ethyl-S-(2-dimethylaminoethyl)-methylphosphonothioate intoxication (p.o.) alone and in combination with atropine and the reactivators trimedoxime, obidoxime and methoxime. Decrease of acetylcholinesterase activity was not influenced by atropine alone but following treatment with a combination of atropine with the reactivators mentioned, an increase (reactivation) of the blood enzyme was demonstrated. This increase was highest for the combination atropine-trimedoxime and the lowest for the combination atropine-obidoxime.
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Bosković B, Tadić V, Kusić R. Reactivating and protective effects of Pro-2PAM in mice poisoned with paraoxon. Toxicol Appl Pharmacol 1980; 55:32-6. [PMID: 7423504 DOI: 10.1016/0041-008x(80)90216-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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PROCEEDINGS OF THE BRITISH PHARMACOLOGICAL SOCIETY. Br J Pharmacol 1980. [DOI: 10.1111/j.1476-5381.1980.tb07899.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Clement JG. Efficacy of pro-PAM (N-methyl-1,6-dihydropyridine-2-carbaldoxime hydrochloride) as a prophylaxis against organophosphate poisoning. Toxicol Appl Pharmacol 1979; 47:305-11. [PMID: 36686 DOI: 10.1016/0041-008x(79)90325-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Bodor N, Roller RG, Selk SJ. Elimination of a quaternary pyridinium salt delivered as its dihydropyridine derivative from brain of mice. J Pharm Sci 1978; 67:685-7. [PMID: 641811 DOI: 10.1002/jps.2600670531] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
1-Methylpyridine-2-carbaldehyde oxime, a quaternary pyridinium salt, can be delivered efficiently through the blood-brain barrier in its dihydropyridine prodrug form. This redox system was used to study the elimination rate from the brain of a small quaternary salt. It was found that the oxime is eliminated relatively fast from the brain, which supports a hypothesis for the existence of an active transport mechanism for eliminating organic ions from the brain. The possibilities of using the pyridinium salt in equilibrium dihydropyridine redox system for specific delivery of drugs to the brain are discussed.
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