1
|
Triandafilova G, Smirnova G, Krasnykh O, Boteva A, Oktyabrsky O. Antimicrobial and Antioxidant Activity of Some Nitrogen-Containing Heterocycles and Their Acyclic Analogues. Indian J Microbiol 2024; 64:482-491. [PMID: 39011024 PMCID: PMC11246309 DOI: 10.1007/s12088-023-01158-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 11/17/2023] [Indexed: 07/17/2024] Open
Abstract
We investigated antimicrobial and antioxidant activity of nitrogen-containing heterocycles and their acyclic analogues, some of which can be considered as promising in terms of biological activity. Based on structure, 26 tested compounds were divided into 4 groups. In the test with 2,2-diphenyl-1-picrylhydrazyl (DPPH), the compounds of the group 2 had the highest radical-binding activity (RBA) (53-78%), while those of group 3 had the lowest values (1.5-5.2%). In oxygen radical absorbance capacity assay, all compounds from groups 1, 2 and 3 showed high RBA: 44-94% at 50 µM. The highest bacteriostatic activity against Escherichia coli was found for four compounds in group 2 (MIC = 0.25-1 mM) and low bacteriostatic activity for group 3 (MIC > 4 mM). Some relationships between the structure of compounds and the values of the MIC are revealed. It was also found that four substances from different groups had the ability to inhibit the formation of colonies in E. coli from 1.3 to 5.7 times. Four compounds reduced specific biofilm formation by 40-60%. The tested substances did not induce the expression of the sulA gene controlled by the SOS system, which indicates the lack of genotoxic activity. None of the tested compounds had pro-oxidant activity. This was shown by both the absence of production hydrogen peroxide in a bacteria-free medium and inability to induce expression of the katG gene encoding HPI catalase in growing E. coli. The data obtained could be useful in the development of new drugs.
Collapse
Affiliation(s)
- Galina Triandafilova
- Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Perm, Russia
- Scientific and Educational Center for Applied Chemical and Biological Research, Perm National Research Polytechnic University, Perm, Russia
| | - Galina Smirnova
- Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Perm, Russia
| | - Olga Krasnykh
- Scientific and Educational Center for Applied Chemical and Biological Research, Perm National Research Polytechnic University, Perm, Russia
| | - Anastasija Boteva
- Scientific and Educational Center for Applied Chemical and Biological Research, Perm National Research Polytechnic University, Perm, Russia
| | - Oleg Oktyabrsky
- Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Perm, Russia
| |
Collapse
|
2
|
Orfali R, Alwatban AZ, Orfali RS, Lau L, Chea N, Alotaibi AM, Nam YW, Zhang M. Oxidative stress and ion channels in neurodegenerative diseases. Front Physiol 2024; 15:1320086. [PMID: 38348223 PMCID: PMC10859863 DOI: 10.3389/fphys.2024.1320086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024] Open
Abstract
Numerous neurodegenerative diseases result from altered ion channel function and mutations. The intracellular redox status can significantly alter the gating characteristics of ion channels. Abundant neurodegenerative diseases associated with oxidative stress have been documented, including Parkinson's, Alzheimer's, spinocerebellar ataxia, amyotrophic lateral sclerosis, and Huntington's disease. Reactive oxygen and nitrogen species compounds trigger posttranslational alterations that target specific sites within the subunits responsible for channel assembly. These alterations include the adjustment of cysteine residues through redox reactions induced by reactive oxygen species (ROS), nitration, and S-nitrosylation assisted by nitric oxide of tyrosine residues through peroxynitrite. Several ion channels have been directly investigated for their functional responses to oxidizing agents and oxidative stress. This review primarily explores the relationship and potential links between oxidative stress and ion channels in neurodegenerative conditions, such as cerebellar ataxias and Parkinson's disease. The potential correlation between oxidative stress and ion channels could hold promise for developing innovative therapies for common neurodegenerative diseases.
Collapse
Affiliation(s)
- Razan Orfali
- Neuroscience Research Department, Research Centre, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Adnan Z. Alwatban
- Neuroscience Research Department, Research Centre, King Fahad Medical City, Riyadh, Saudi Arabia
| | | | - Liz Lau
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| | - Noble Chea
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| | - Abdullah M. Alotaibi
- Neuroscience Research Department, Research Centre, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Young-Woo Nam
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| | - Miao Zhang
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| |
Collapse
|
3
|
Ii H, Nohara Y, Yoshiya T, Masuda S, Tsuda S, Oishi S, Friedman J, Kawabe T, Nakata S. Identification of U83836E as a γ-glutamylcyclotransferase inhibitor that suppresses MCF7 breast cancer xenograft growth. Biochem Biophys Res Commun 2021; 549:128-134. [PMID: 33676180 DOI: 10.1016/j.bbrc.2021.02.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 02/22/2021] [Indexed: 11/25/2022]
Abstract
γ-Glutamylcyclotransferase (GGCT) is involved in glutathione homeostasis, in which it catalyzes the reaction that generates 5-oxoproline and free amino acids from γ-glutamyl peptides. Increasing evidence shows that GGCT has oncogenic functions and is overexpressed in various cancer tissues, and that inhibition of GGCT activity exerts anticancer effects in vitro and in vivo. Here, we demonstrate that U83836E ((2R)-2-[[4-(2,6-dipyrrolidin-1-ylpyrimidin-4-yl)piperazin-1-yl]methyl]-3,4-dihydro-2,5,7,8,-tetramethyl-2H-1-benzopyran-6-ol, dihydrochloride), a lazaroid that inhibits lipid peroxidation, inhibits GGCT enzymatic activity. U83836E was identified from a high-throughput screen of low molecular weight compounds using a fluorochrome-conjugated GGCT probe. We directly quantified that U83836E specifically inhibited GGCT by measuring the product of a fluorochrome-conjugated GGCT substrate assay, and showed that U83836E inhibited GGCT activity in extracts of NIH3T3 cells overexpressing GGCT. Moreover, U83836E significantly inhibited tumor growth in a xenograft model that used immunodeficient mice orthotopically inoculated with MCF7 human breast cancer cells. These results indicate that U83836E may be a useful GGCT inhibitor for the development of potential cancer therapeutics.
Collapse
Affiliation(s)
- Hiromi Ii
- Department of Clinical Oncology, Kyoto Pharmaceutical University, Misasagi-Nakauchicho 5, Yamashina, Kyoto, 607-8414, Japan
| | - Yukie Nohara
- Peptide Institute, Inc., 7-2-9 Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan
| | - Taku Yoshiya
- Peptide Institute, Inc., 7-2-9 Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan
| | - Shun Masuda
- Peptide Institute, Inc., 7-2-9 Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan
| | - Shugo Tsuda
- Peptide Institute, Inc., 7-2-9 Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan
| | - Shinya Oishi
- Department of Medicinal Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto, 607-8412, Japan; Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, 606-8501, Japan
| | | | - Takumi Kawabe
- CanBas Co., Ltd., 2-2-1 Otemachi Numazu, Shizuoka, 410-0801, Japan
| | - Susumu Nakata
- Department of Clinical Oncology, Kyoto Pharmaceutical University, Misasagi-Nakauchicho 5, Yamashina, Kyoto, 607-8414, Japan.
| |
Collapse
|
4
|
Kaproń B, Czarnomysy R, Wysokiński M, Andrys R, Musilek K, Angeli A, Supuran CT, Plech T. 1,2,4-Triazole-based anticonvulsant agents with additional ROS scavenging activity are effective in a model of pharmacoresistant epilepsy. J Enzyme Inhib Med Chem 2020; 35:993-1002. [PMID: 32253957 PMCID: PMC7178883 DOI: 10.1080/14756366.2020.1748026] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 12/16/2022] Open
Abstract
There are numerous studies supporting the contribution of oxidative stress to the pathogenesis of epilepsy. Prolonged oxidative stress is associated with the overexpression of ATP-binding cassette transporters, which results in antiepileptic drugs resistance. During our studies, three 1,2,4-triazole-3-thione derivatives were evaluated for the antioxidant activity and anticonvulsant effect in the 6 Hz model of pharmacoresistant epilepsy. The investigated compounds exhibited 2-3 times more potent anticonvulsant activity than valproic acid in 6 Hz test in mice, which is well-established preclinical model of pharmacoresistant epilepsy. The antioxidant/ROS scavenging activity was confirmed in both single-electron transfer-based methods (DPPH and CUPRAC) and during flow cytometric analysis of total ROS activity in U-87 MG cells. Based on the enzymatic studies on human carbonic anhydrases (CAs), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), one can assume that the herein investigated drug candidates will not impair the cognitive processes mediated by CAs and will have minimal off-target cholinergic effects.
Collapse
Affiliation(s)
- Barbara Kaproń
- Department of Clinical Genetics, I Faculty of Medicine with Dentistry Division, Medical University of Lublin, Lublin, Poland
| | - Robert Czarnomysy
- Department of Synthesis and Technology of Drugs, Faculty of Pharmacy, Medical University of Białystok, Bialystok, Poland
| | - Mariusz Wysokiński
- Department of Basic Nursing and Medical Teaching, Chair of Development in Nursing, Faculty of Health Sciences, Medical University of Lublin, Lublin, Poland
| | - Rudolf Andrys
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Andrea Angeli
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Firenze, Italy
| | - Claudiu T. Supuran
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Firenze, Italy
| | - Tomasz Plech
- Department of Pharmacology, Faculty of Health Sciences, Medical University of Lublin, Lublin, Poland
| |
Collapse
|
5
|
van der Peet PL, Sandanayake S, Jarrott B, Williams SJ. Discovery of N-Aryloxypropylbenzylamines as Voltage-Gated Sodium Channel Na V 1.2-Subtype-Selective Inhibitors. ChemMedChem 2019; 14:570-582. [PMID: 30676691 DOI: 10.1002/cmdc.201800781] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/22/2019] [Indexed: 11/07/2022]
Abstract
We previously reported that a lipophilic N-(4'-hydroxy-3',5'-di-tert-butylbenzyl) derivative (1) of the voltage-gated sodium channel blocker mexiletine, was a more potent sodium channel blocker in vitro and in vivo. We demonstrate that replacing the chiral methylethylene linker between the amine and di-tert-butylphenol with an achiral 1,3-propylene linker (to give (2)) maintains potency in vitro. We synthesized 25 analogues bearing the 1,3-propylene linker and found that minor structural changes resulted in pronounced changes in state dependence of blocking human NaV 1.2 and 1.6 channels by high-throughput patch-clamp analysis. Compared to mexiletine, compounds 1 and 2 are highly selective NaV 1.2 inhibitors and >500 times less potent in inhibiting NaV 1.6 channels. On the other hand, a derivative (compound 4) bearing 2,6-dimethoxy groups in place of the 2,6-dimethyl groups found in mexiletine was found to be the most potent inhibitor, but is nonselective against both channels in the tonic, frequency-dependent and inactivated states. In a kindled mouse model of refractory epilepsy, compound 2 inhibited seizures induced by 6 Hz 44 mA electrical stimulation with an IC50 value of 49.9±1.6 mg kg-1 . As established sodium channel blockers do not suppress seizures in this mouse model, this indicates that 2 could be a promising candidate for treating pharmaco-resistant epilepsy.
Collapse
Affiliation(s)
- Phillip L van der Peet
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Saman Sandanayake
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Bevyn Jarrott
- Florey Institute of Neuroscience & Mental Health, Parkville, Victoria, 3010, Australia
| | - Spencer J Williams
- School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, 3010, Australia
| |
Collapse
|
6
|
Kondratskyi A, Kondratska K, Skryma R, Prevarskaya N. Ion channels in the regulation of apoptosis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:2532-46. [PMID: 25450339 DOI: 10.1016/j.bbamem.2014.10.030] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/08/2014] [Accepted: 10/20/2014] [Indexed: 02/07/2023]
Abstract
Apoptosis, a type of genetically controlled cell death, is a fundamental cellular mechanism utilized by multicellular organisms for disposal of cells that are no longer needed or potentially detrimental. Given the crucial role of apoptosis in physiology, deregulation of apoptotic machinery is associated with various diseases as well as abnormalities in development. Acquired resistance to apoptosis represents the common feature of most and perhaps all types of cancer. Therefore, repairing and reactivating apoptosis represents a promising strategy to fight cancer. Accumulated evidence identifies ion channels as essential regulators of apoptosis. However, the contribution of specific ion channels to apoptosis varies greatly depending on cell type, ion channel type and intracellular localization, pathology as well as intracellular signaling pathways involved. Here we discuss the involvement of major types of ion channels in apoptosis regulation. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
Collapse
Affiliation(s)
- Artem Kondratskyi
- Inserm, U-1003, Equipe labellisée par la Ligue Nationale Contre le Cancer, Laboratory of Excellence, Ion Channels Science and Therapeutics, Université Lille 1, Villeneuve d'Ascq, France
| | - Kateryna Kondratska
- Inserm, U-1003, Equipe labellisée par la Ligue Nationale Contre le Cancer, Laboratory of Excellence, Ion Channels Science and Therapeutics, Université Lille 1, Villeneuve d'Ascq, France
| | - Roman Skryma
- Inserm, U-1003, Equipe labellisée par la Ligue Nationale Contre le Cancer, Laboratory of Excellence, Ion Channels Science and Therapeutics, Université Lille 1, Villeneuve d'Ascq, France
| | - Natalia Prevarskaya
- Inserm, U-1003, Equipe labellisée par la Ligue Nationale Contre le Cancer, Laboratory of Excellence, Ion Channels Science and Therapeutics, Université Lille 1, Villeneuve d'Ascq, France.
| |
Collapse
|
7
|
El-Dayem SMA, Fouda FM, Ali EHA, Motelp BAAE. The antitumor effects of tetrodotoxin and/or doxorubicin on Ehrlich ascites carcinoma-bearing female mice. Toxicol Ind Health 2013; 29:404-417. [DOI: 10.1177/0748233711434955] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The study aimed to investigate the antitumor effect of tetrodotoxin (TTX) and/or doxorubicin (DOX) on Ehrlich ascites carcinoma (EAC)-bearing mice through the investigated biochemical parameters. TTX and/or DOX with or without N-acetylcystiene were administrated after 10 days into EAC-female mice for a period of 2 weeks in six equal doses. Treatment with TTX or DOX caused a significant decrease in the mean tumor weight and an increase in the cumulative mean survival time when compared with EAC group. All the treatments reduced the elevated liver tumor markers and increased liver antioxidant enzymes under investigation in comparison with EAC. Hepatic cells, suffered severely from degeneration and karriolysis in EAC group, revealed some improvement as appearance of healthy hepatocytes by TTX treatment. The present results suggested that TTX had a more powerful inhibitor effect on EAC growth than DOX and TTX plus DOX treatments reflected by antitumor biochemical and histological studies.
Collapse
Affiliation(s)
- Samiha M Abd El-Dayem
- Department of Zoology, Faculty of Women’s for Arts, Science and Education, Ain Shams University, Egypt
| | - Fatma M Fouda
- Department of Zoology, Faculty of Women’s for Arts, Science and Education, Ain Shams University, Egypt
| | - Elham H A Ali
- Department of Zoology, Faculty of Women’s for Arts, Science and Education, Ain Shams University, Egypt
| | - Bosy A Abd El Motelp
- Department of Zoology, Faculty of Women’s for Arts, Science and Education, Ain Shams University, Egypt
| |
Collapse
|
8
|
Simard JM, Woo SK, Gerzanich V. Transient receptor potential melastatin 4 and cell death. Pflugers Arch 2012; 464:573-82. [PMID: 23065026 PMCID: PMC3513597 DOI: 10.1007/s00424-012-1166-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 09/25/2012] [Accepted: 09/25/2012] [Indexed: 12/12/2022]
Abstract
Cell death proceeds by way of a variety of “cell death subroutines,” including several types of “apoptosis,” “regulated necrosis,” and others. “Accidental necrosis” due to profound adenosine triphosphate (ATP) depletion or oxidative stress is distinguished from regulated necrosis by the absence of death receptor signaling. However, both accidental and regulated necrosis have in common the process of “oncosis,” a physiological process characterized by Na+ influx and cell volume increase that, in necrotic cell death, is required to produce the characteristic features of membrane blebbing and membrane rupture. Here, we review emerging evidence that the monovalent cation channel, transient receptor potential melastatin 4 (TRPM4), is involved in the cell death process of oncosis. Potential involvement of TRPM4 in oncosis is suggested by the fact that the two principal regulators of TRPM4, intracellular ATP and Ca2+, are both altered during necrosis in the direction that causes TRPM4 channel opening. Under physiological conditions, activation of TRPM4 promotes Na+ influx and cell depolarization. Under pathological conditions, unchecked activation of TRPM4 leads to Na+ overload, cell volume increase, blebbing and cell membrane rupture, the latter constituting the irreversible end stage of necrosis. Emerging data indicate that TRPM4 plays a crucial role as end executioner in the accidental necrotic death of ATP-depleted or redox-challenged endothelial and epithelial cells, both in vitro and in vivo. Future studies will be needed to determine whether TRPM4 also plays a role in regulated necrosis and apoptosis.
Collapse
Affiliation(s)
- J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, MD 21201-1595, USA.
| | | | | |
Collapse
|
9
|
Kolosov A, Goodchild CS, Cooke I. Studies of Synergy between Morphine and a Novel Sodium Channel Blocker, CNSB002, in Rat Models of Inflammatory and Neuropathic Pain. PAIN MEDICINE 2010; 11:106-18. [DOI: 10.1111/j.1526-4637.2009.00768.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Investigating the in vitro metabolism of veratridine: characterization of metabolites and involved cytochrome P450 isoforms. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 877:141-8. [PMID: 19097948 DOI: 10.1016/j.jchromb.2008.11.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 11/18/2008] [Accepted: 11/26/2008] [Indexed: 11/24/2022]
Abstract
Veratridine is a lipid-soluble alkaloid extracted from Veratrum officinale and other species of the family Liliaceae. Veratridine prevents inactivation of Na(+) channel via binding the receptor site 2, causes influx of sodium ion and depolarization and induces apoptosis of neuronal cells. In the present study, we investigated the metabolism of veratridine and the effects of selective cytochrome P450 (CYP) inhibitors on the metabolism of veratridine in rat liver microsomes. The metabolites were separated and assayed by liquid-chromatography-electrospray ionization-ion trap tandem mass spectrometry (LC-ESI-QIT-MSn), and further identified by their mass spectra and chromatographic behaviors. Result showed that four CYP isoforms (CYP1A, CYP2B, CYP2E1, CYP3A) were involved in the metabolism of veratridine in vitro and seven metabolites of veratridine were detected incubating with rat liver microsomes. Some of the metabolites were presumed to be potential mediates of neurotoxicity via protein binging. Further research in vivo needs to link the metabolism of veratridine to its toxicity.
Collapse
|
11
|
Jessica Chen M, Sepramaniam S, Armugam A, Shyan Choy M, Manikandan J, Melendez AJ, Jeyaseelan K, Sang Cheung N. Water and ion channels: crucial in the initiation and progression of apoptosis in central nervous system? Curr Neuropharmacol 2008; 6:102-16. [PMID: 19305791 PMCID: PMC2647147 DOI: 10.2174/157015908784533879] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 09/09/2007] [Accepted: 10/01/2007] [Indexed: 12/14/2022] Open
Abstract
Programmed cell death (PCD), is a highly regulated and sophisticated cellular mechanism that commits cell to isolated death fate. PCD has been implicated in the pathogenesis of numerous neurodegenerative disorders. Countless molecular events underlie this phenomenon, with each playing a crucial role in death commitment. A precedent event, apoptotic volume decrease (AVD), is ubiquitously observed in various forms of PCD induced by different cellular insults. Under physiological conditions, cells when subjected to osmotic fluctuations will undergo regulatory volume increase/decrease (RVI/RVD) to achieve homeostatic balance with neurons in the brain being additionally protected by the blood-brain-barrier. However, during AVD following apoptotic trigger, cell undergoes anistonic shrinkage that involves the loss of water and ions, particularly monovalent ions e.g. K(+), Na(+) and Cl(-). It is worthwhile to concentrate on the molecular implications underlying the loss of these cellular components which posed to be significant and crucial in the successful propagation of the apoptotic signals. Microarray and real-time PCR analyses demonstrated several ion and water channel genes are regulated upon the onset of lactacystin (a proteosomal inhibitor)-mediated apoptosis. A time course study revealed that gene expressions of water and ion channels are being modulated just prior to apoptosis, some of which are aquaporin 4 and 9, potassium channels and chloride channels. In this review, we shall looked into the molecular protein machineries involved in the execution of AVD in the central nervous system (CNS), and focus on the significance of movements of each cellular component in affecting PCD commitment, thus provide some pharmacological advantages in the global apoptotic cell death.
Collapse
Affiliation(s)
- Minghui Jessica Chen
- Departments of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Sugunavathi Sepramaniam
- Departments of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Arunmozhiarasi Armugam
- Departments of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Meng Shyan Choy
- Departments of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Jayapal Manikandan
- Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Alirio J Melendez
- Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Kandiah Jeyaseelan
- Departments of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Nam Sang Cheung
- Departments of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| |
Collapse
|
12
|
Nicolazzo JA, Nguyen TT, Katneni K, Steuten JA, Smith G, Jarrott B, Callaway JK, Charman SA. Pharmacokinetics and brain uptake of AM-36, a novel neuroprotective agent, following intravenous administration to rats. J Pharm Pharmacol 2008; 60:171-8. [PMID: 18237464 DOI: 10.1211/jpp.60.2.0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The plasma pharmacokinetics and brain uptake of the novel neuroprotective agent AM-36 (1-(2-(4-chlorophenyl)-2-hydroxy)ethyl-4-(3,5-bis-(1,1dimethylethyl)-4-hydroxyphenyl) methylpiperazine) were assessed over 72 h following i.v. administration to male Sprague-Dawley rats. At nominal i.v. doses of 0.2, 1 and 3mg kg(-1), AM-36 exhibited an extremely large volume of distribution (18.2-24.6 L kg(-1)) and a long terminal elimination half-life, ranging from 25.2 to 37.7 h. Over this dose range, AM-36 exhibited linear pharmacokinetics, with no apparent change in clearance, volume of distribution or dose-normalised area under the plasma concentration - time curve. AM-36 was very highly bound to plasma proteins (> 99.6%); however, this did not appear to affect the ability of AM-36 to permeate the blood-brain barrier. Following a single i.v. dose of AM-36 at 3mg kg(-1) to rats, brain concentrations were detected for up to 72 h, and the brain-to-plasma ratios were high at all time points (ranging from 8.2 at 5 min post-dose to 0.9 at 72 h post-dose). The very high brain uptake of AM-36 supports previous in-vivo efficacy studies demonstrating the neuroprotective effects of this compound when administered to rats with middle cerebral artery occlusion.
Collapse
Affiliation(s)
- Joseph A Nicolazzo
- Centre for Drug Candidate Optimisation, Victorian College of Pharmacy, Monash University, Parkville, Victoria 3052, Australia
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Xiao X, Liu J, Hu J, Li T, Zhang Y. Protective Effect of Protopine on the Focal Cerebral Ischaemic Injury in Rats. Basic Clin Pharmacol Toxicol 2007; 101:85-9. [PMID: 17651307 DOI: 10.1111/j.1742-7843.2007.00075.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Protopine, an isoquinoline alkaloidis, is known to produce many effects such as vasodilation, down-regulation of glutamate levels in brain and decrease of intracellular calcium. However, so far there is no report on the effect of protopine in cerebral ischaemia. In this study, the effect of protopine on the focal cerebral ischaemia was investigated in rats. Male Sprague-Dawley rats were divided into five groups: sham-operated group, vehicle-treated group and three doses of protopine-treated groups (0.98, 1.96 and 3.92 mg/kg). Protopine was intraperitoneally administered to rats once daily for 3 days prior to the ischaemia and 0.9% normal saline to rats in the vehicle-treated group in the same pattern. Rats in the sham-operated group were given 0.9% normal saline without the ischaemia. The focal cerebral ischaemia was induced by the middle cerebral artery occlusion for 24 hr via the intraluminal filament technique. The results showed that pre-treatment with protopine reduced the cerebral infarction ratio and serum lactate dehydrogenase activity, and improved the ischaemia-induced neurological deficit score and histological changes of brain in a dose-dependent manner. The further studies demonstrated that protopine increased superoxide dismutase activity in serum, and decreased total calcium and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL)-positive cells in the ischaemic brain tissue in the middle cerebral artery occlusion rats. The results indicate that protopine is able to produce an effective protection on the injury caused by the focal cerebral ischaemia in rats possibly through the multiple effects of calcium antagonism, antioxidation and depression of cell apoptosis.
Collapse
Affiliation(s)
- Xianghua Xiao
- Department of Pharmacology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, China
| | | | | | | | | |
Collapse
|
14
|
Bortner CD, Cidlowski JA. Cell shrinkage and monovalent cation fluxes: role in apoptosis. Arch Biochem Biophys 2007; 462:176-88. [PMID: 17321483 PMCID: PMC1941616 DOI: 10.1016/j.abb.2007.01.020] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 01/18/2007] [Accepted: 01/23/2007] [Indexed: 12/25/2022]
Abstract
The loss of cell volume or cell shrinkage has been a morphological hallmark of the programmed cell death process known as apoptosis. This isotonic loss of cell volume has recently been term apoptotic volume decrease or AVD to distinguish it from inherent volume regulatory responses that occurs in cells under anisotonic conditions. Recent studies examining the intracellular signaling pathways that result in this unique cellular characteristic have determined that a fundamental movement of ions, particularly monovalent ions, underlie the AVD process and plays an important role on controlling the cell death process. An efflux of intracellular potassium was shown to be a critical aspect of the AVD process, as preventing this ion loss could protect cells from apoptosis. However, potassium plays a complex role as a loss of intracellular potassium has also been shown to be beneficial to the health of the cell. Additionally, the mechanisms that a cell employs to achieve this loss of intracellular potassium vary depending on the cell type and stimulus used to induce apoptosis, suggesting multiple ways exist to accomplish the same goal of AVD. Additionally, sodium and chloride have been shown to play a vital role during cell death in both the signaling and control of AVD in various apoptotic model systems. This review examines the relationship between this morphological change and intracellular monovalent ions during apoptosis.
Collapse
Affiliation(s)
- Carl D Bortner
- The Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Department of Health and Human Services, National Institutes of Health, Research Triangle Park, NC 27709, USA.
| | | |
Collapse
|
15
|
Weston RM, Jarrott B, Ishizuka Y, Callaway JK. AM-36 modulates the neutrophil inflammatory response and reduces breakdown of the blood brain barrier after endothelin-1 induced focal brain ischaemia. Br J Pharmacol 2006; 149:712-23. [PMID: 17016500 PMCID: PMC2014659 DOI: 10.1038/sj.bjp.0706918] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE Following transient focal stroke, rapid accumulation and activation of neutrophils in the ischaemic region is deleterious due to release of reactive oxygen species and myeloperoxidase (MPO). The purpose of this study was to examine whether AM-36, both a Na+ channel blocker and an antioxidant, afforded neuroprotection by modulating neutrophil accumulation into brain, following endothelin-1 (ET-1) induced middle cerebral artery occlusion (MCAo) in conscious rats. EXPERIMENTAL APPROACH AM-36 was administered at 3 and 24 h after ET-1-induced MCAo. Functional recovery was determined using grid-walking and cylinder tests. Image analysis of brain sections was used to determine infarct volume. The effect of AM-36 on neutrophil infiltration and their interaction with macrophages was examined in rats at 48 h following MCAo by both an MPO assay and double-label immunofluorescence. Blood brain barrier (BBB) breakdown was measured by the area stained by intravenous Evans Blue. KEY RESULTS AM-36 reduced functional deficits in both tests such that no difference existed from pre-ischaemic values at 48 h. Neutrophil infiltration, assessed by MPO activity, and infarct volume were significantly reduced following AM-36 administration by 54 and 60% respectively. Similarly, immunofluorescence revealed that AM-36 reduced neutrophil infiltration by approximately 50% in selected brain regions, when compared to controls, and also modulated macrophage phagocytosis of neutrophils. Breakdown of the BBB was significantly reduced by 60% following AM-36 treatment. CONCLUSIONS AND IMPLICATIONS These findings suggest that AM-36 can directly modulate the neutrophil inflammatory response and reduce BBB breakdown following MCAo.
Collapse
Affiliation(s)
- R M Weston
- Department of Pharmacology, Monash University Clayton, Australia
- Howard Florey Institute, The University of Melbourne Parkville, Australia
| | - B Jarrott
- Howard Florey Institute, The University of Melbourne Parkville, Australia
| | - Y Ishizuka
- Department of Pharmacology, Monash University Clayton, Australia
- Department of Psychiatry, Miyazaki Medical College Kihara, Kiyotake, Miyazaki, Japan
| | - J K Callaway
- Howard Florey Institute, The University of Melbourne Parkville, Australia
- Author for correspondence:
| |
Collapse
|
16
|
Lin YH, Liu AH, Pan Y, Westenbroek C, Ter Horst GJ, Yu HM, Li XJ. Reduction in the in vitro expression of Brain–Pancreas Relative Protein by oxygen and glucose-deprivation. Mol Cell Biochem 2006; 295:199-204. [PMID: 16953335 DOI: 10.1007/s11010-006-9289-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Accepted: 07/24/2006] [Indexed: 11/30/2022]
Abstract
Brain-Pancreas Relative Protein (BPRP) is a novel protein found in our laboratory. In previous study we observed a significant reduction in BPRP in ischemic brain of rat. Here we undertook this study to explore the possible mediating mechanism by which oxygen and glucose-deprivation culture (OGD), a model of ischemia in vitro, decreased the expression of BPRP in PC12 cells. BPRP was found to be expressed in PC12 cells and OGD caused a significant reduction in BPRP expression. The effect of OGD was primarily mediated by reactive oxygen species (ROS) because OGD upregulated the production of ROS and the inhibitors of protein kinase C, calmodulin, free radical scavengers reduced OGD-induced ROS production, while increased the expression of BPRP in PC12 cells. These data indicate that OGD decreases the expression of BPRP via enhanced formation of intracellular ROS.
Collapse
Affiliation(s)
- Yan-Hua Lin
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Natural & Biomimetic Drugs, Peking University Health Science Center, Xueyuan Road 38#, Beijing, 100083, China.
| | | | | | | | | | | | | |
Collapse
|
17
|
Silva Freitas EM, Fagian MM, da Cruz Höfling MA. Effects of veratrine and veratridine on oxygen consumption and electrical membrane potential of isolated rat skeletal muscle and liver mitochondria. Toxicon 2006; 47:780-7. [PMID: 16626771 DOI: 10.1016/j.toxicon.2006.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Revised: 02/14/2006] [Accepted: 02/15/2006] [Indexed: 11/28/2022]
Abstract
We have previously shown that veratrine, a mixture of alkaloids known as Veratrum alkaloids, produces skeletal muscle toxicity, and there is evidence that veratrine interferes with the energetics of various systems, including cardiomyocytes and synaptosomes. In this work, we explored the effects of veratrine and veratridine, a component of this mixture, in rat skeletal muscle mitochondria and compared the results with those seen in liver mitochondria. Veratrine and veratridine alkaloids caused a significant concentration-dependent decrease in the rate of state 3 respiration, respiratory control (RCR) and ADP/O ratios in isolated rat skeletal muscle mitochondria (RMM), but not in rat liver mitochondria (RLM) supported by either NADH-linked substrates or succinate. The oxygen consumption experiments showed that RMM were more susceptible to the toxic action of Veratrum alkaloids than RLM. The addition of veratrine (250 microg/ml) to RMM caused dissipation of the mitochondrial electrical membrane potential during succinate oxidation, but this effect was totally reversed by adding ATP. These results indicate that there are chemical- and tissue-specific toxic effects of veratrine and veratridine on mitochondrial respiratory chain complexes. Identification of the specific respiratory chain targets involved should provide a better understanding of the molecular mechanisms of the toxicity of these agents.
Collapse
Affiliation(s)
- Erika Maria Silva Freitas
- Departamento de Histologia e Embriologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-970 Campinas, SP, Brazil
| | | | | |
Collapse
|
18
|
Franco R, Bortner CD, Cidlowski JA. Potential Roles of Electrogenic Ion Transport and Plasma Membrane Depolarization in Apoptosis. J Membr Biol 2006; 209:43-58. [PMID: 16685600 DOI: 10.1007/s00232-005-0837-5] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Indexed: 12/15/2022]
Abstract
Apoptosis is characterized by the programmed activation of specific biochemical pathways leading to the organized demise of cells. To date, aspects of the intracellular signaling machinery involved in this phenomenon have been extensively dissected and characterized. However, recent studies have elucidated a novel role for changes in the intracellular milieu of the cells as important modulators of the cell death program. Specially, intracellular ionic homeostasis has been reported to be a determinant in both the activation and progression of the apoptotic cascade. Several apoptotic insults trigger specific changes in ionic gradients across the plasma membrane leading to depolarization of the plasma membrane potential (PMP). These changes lead to ionic imbalance early during apoptosis. Several studies have also suggested the activation and/or modulation of specific ionic transport mechanisms including ion channels, transporters and ATPases, as mediators of altered intracellular ionic homeostasis leading to PMP depolarization during apoptosis. However, the role of PMP depolarization and of the changes in ionic homeostasis during the progression of apoptosis are still unclear. This review summarizes the current knowledge regarding the causes and consequences of PMP depolarization during apoptosis. We also review the potential electrogenic ion transport mechanisms associated with this event, including the net influx/efflux of cations and anions. An understanding of these mechamisms could lead to the generation of new therapeutic approaches for a variety of diseases involving apoptosis.
Collapse
Affiliation(s)
- R Franco
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | | | | |
Collapse
|
19
|
Jiang ZG, Lebowitz MS, Ghanbari HA. Neuroprotective activity of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (PAN-811), a cancer therapeutic agent. CNS DRUG REVIEWS 2006; 12:77-90. [PMID: 16834759 PMCID: PMC6741723 DOI: 10.1111/j.1527-3458.2006.00077.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) is a highly-hydrophobic small molecule that was originally developed for cancer therapy (Triapine, Vion Pharmaceuticals) due to its ability to inhibit ribonucleotide reductase, a key enzyme required for DNA synthesis. 3-AP has a high affinity for divalent cations, chelating the Fe(2+) at the R2 subunit of the enzyme and inhibiting formation of a tyrosyl radical essential for ribonucleotide reduction. We have demonstrated that 3-AP is also a potent neuroprotectant (as such, it is referred to as "PAN-811"). In vitro it completely blocks ischemic neurotoxicity at a concentration of 0.5 microM (EC(50) approximate, equals 0.35 microM) and hypoxic toxicity at 1.2 microM (EC(50) approximate, equals 0.75 microM). Full protection of primary cortical and striatal neurons can be achieved with 3-AP when it is added to the medium at up to six hours after an ischemic insult. 3-AP also suppresses cell death induced by neurotoxic agents, including staurosporine, veratridine and glutamate, indicating activity against a central target(s) in the neurodegenerative process. 3-AP acts via neutralization of two important intracellular effectors of excitatory neurotoxicity; calcium and free radicals. Its reported ability to elevate anti-apoptotic proteins is likely to be a consequence of the suppression of excessive intracellular free calcium. In a rat model of transient ischemia, a single bolus delivery of 3-AP 1 h after the initiation of ischemic attack reduced infarct volume by 59% when administered i.c.v. (50 mug per rat) and by 35% when administered i.v. (1 mg/kg). In Phase I clinical trials in cancer therapy 3-AP had no cardiovascular, CNS or other major adverse effects. Thus, 3-AP has a high potential for development as a novel, potent neuroprotectant for the treatment of neurodegenerative diseases.
Collapse
Affiliation(s)
- Zhi-Gang Jiang
- Neurodegenerative Diseases, Panacea Pharmaceuticals, Inc., Gaithersburg, Maryland 20877, USA.
| | | | | |
Collapse
|
20
|
Yakovlev AG, Faden AI. Mechanisms of neural cell death: implications for development of neuroprotective treatment strategies. NeuroRx 2005; 1:5-16. [PMID: 15717003 PMCID: PMC534908 DOI: 10.1602/neurorx.1.1.5] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
It has been increasingly recognized that cell death phenotypes and their molecular mechanisms are highly diverse. Necrosis is no longer considered a single entity, passively mediated by energy failure. Moreover, caspase-dependent apoptosis is not the only pathway involved in programmed cell death or even the only apoptotic mechanism. Recent experimental work emphasizes the diverse and interrelated nature of cell death mechanisms. Thus, there are both caspase-dependent and caspase-independent forms of apoptosis, which may differ morphologically as well as mechanistically. There are also necrotic-like phenotypes that require de novo protein synthesis and are, therefore, forms of programmed cell death. In addition, forms of cell death showing certain morphological features of both necrosis and apoptosis have been identified, leading to the term aponecrosis. Considerable experimental evidence also shows that modulation of one form of cell death may lead to another. Together, these observations underscore the need to substantially revise our conceptions about neuroprotection strategies. Use of multiple treatments that target different cell death cascades, or single agents that moderate multiple cell death pathways, is likely to lead to more effective neuroprotection for clinical disorders.
Collapse
Affiliation(s)
- Alexander G Yakovlev
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | | |
Collapse
|
21
|
Chen RW, Yao C, Lu XCM, Jiang ZG, Whipple R, Liao Z, Ghanbari HA, Almassian B, Tortella FC, Dave JR. PAN-811 (3-Aminopyridine-2-carboxaldehyde thiosemicarbazone), a novel neuroprotectant, elicits its function in primary neuronal cultures by up-regulating Bcl-2 expression. Neuroscience 2005; 135:191-201. [PMID: 16084648 DOI: 10.1016/j.neuroscience.2005.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Revised: 01/25/2005] [Accepted: 02/01/2005] [Indexed: 02/02/2023]
Abstract
Neurotoxicity in primary neurons was induced using hypoxia/hypoglycemia (H/H), veratridine (10microM), staurosporine (1microM) or glutamate (100microM), which resulted in 72%, 67%, 75% and 66% neuronal injury, respectively. 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (PAN-811; 10microM; Panacea Pharmaceuticals, Gaithersburg, MD) pretreatment for 24 h provided maximal neuroprotection of 89%, 42%, 47% and 89% against these toxicities, respectively. Glutamate or H/H treatment of cells increased cytosolic cytochrome c levels, which was blocked by pretreatment of cells with PAN-811. Pretreatment of neurons with PAN-811 produced a time-dependent increase in the protein level of Bcl-2, which was evident even after glutamate or H/H treatments. An up-regulation in the expression of the p53 and Bax genes was also observed following exposure to these neurotoxic insults; however, this increase was not suppressed by PAN-811 pretreatment. Functional inhibition of Bcl-2 by HA14-1 reduced the neuroprotective efficacy of PAN-811. PAN-811 treatment also abolished glutamate or H/H-mediated internucleosomal DNA fragmentation.
Collapse
Affiliation(s)
- R-W Chen
- Department of Applied Neurobiology, Division of Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Callaway JK, Castillo-Melendez M, Giardina SF, Krstew EK, Beart PM, Jarrott B. Sodium channel blocking activity of AM-36 and sipatrigine (BW619C89): in vitro and in vivo evidence. Neuropharmacology 2004; 47:146-55. [PMID: 15165842 DOI: 10.1016/j.neuropharm.2004.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2003] [Revised: 02/12/2004] [Accepted: 03/01/2004] [Indexed: 11/20/2022]
Abstract
Sodium channel blockers are neuroprotective against cerebral ischemia in animal models. A novel neuroprotective compound AM-36, when screened for activity at the most common receptor and ion channel binding sites, revealed activity at site 2 Na+ channels. Studies then investigated this Na+ channel blocking activity in vitro and in vivo relative to other Na+ channel blockers, including the neuroprotective agent sipatrigine (BW619C89). AM-36 inhibited batrachotoxinin (BTX)-sensitive Na+ channel binding in rat brain homogenates with an IC50 of 0.28 microM. Veratridine (100 microM)-induced neurotoxicity in murine cerebellar granule cells was completely inhibited by AM-36 (1.7 microM) compared to only partial inhibition by sipatrigine (26 microM). Veratridine-stimulated glutamate release, as measured through a microdialysis probe in the cortex of anesthetised rats, was inhibited by 90% by superfusion of AM-36 (1000 microM). In the endothelin-1 (ET-1) model of middle cerebral artery occlusion (MCAo) in conscious rats, both AM-36 (6 mg/kg i.p.) and sipatrigine (10 mg/kg i.p.) 30 min post-MCAo significantly reduced cortical, but not striatal infarct volume. As the refractiveness of the striatum is likely to be dependent on the route and time of drug administration, AM-36 (1 mg/kg i.v.) was administered 3 or 5 h after MCAo and significantly reduced both cortical and striatal infarct volumes. The present studies demonstrate Na+ channel blocking activity of AM-36 both in vitro and in vivo, together with significant neuroprotection when administration is delayed up to 5 h following experimental stroke.
Collapse
Affiliation(s)
- J K Callaway
- Department of Physiology, Monash University, Clayton, Vic. 3800, Australia.
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
Rifampicin is an antibacterial agent that is widely used in tuberculosis and leprosy therapy. Interestingly, some experimental studies indicate that rifampicin acts as a hydroxyl radical scavenger and a glucocorticoid receptor activator. In this study, the neuroprotective effect of rifampicin was evaluated after transient and permanent focal cerebral ischemia. Anaesthetized male C57BL/6j mice were submitted to permanent or transient thread occlusion of the middle cerebral artery (MCA). Reperfusion in transient ischemia was initiated 30 min later by thread retraction. Rifampicin or vehicle were applied intraperitoneally before permanent or immediately after 30 min of transient ischemia. Later, 24 h after permanent or transient ischemia, animals were re-anesthetized and decapitated. Brain injury was evaluated by triphenyltetrazolium chloride staining (TTC), terminal transferase biotinylated-dUTP nick end labeling (TUNEL) and cresyl violet staining. A 20-mg/kg sample of rifampicin showed a significant neuroprotection after cerebral ischemia. The number of TUNEL-positive cells in the striatum, where disseminated tissue injury was observed, was also reduced by application of rifampicin as compared with vehicle-treated animals. The present report shows that administration of rifampicin efficiently reduces brain injury after permanent and transient focal cerebral ischemia in mice.
Collapse
Affiliation(s)
- Burak Yulug
- Department of Neurology, University of Dokuz Eylül, TR-35340, Izmir, Turkey
| | | | | | | |
Collapse
|
24
|
Lei B, Popp S, Capuano-Waters C, Cottrell JE, Kass IS. Lidocaine attenuates apoptosis in the ischemic penumbra and reduces infarct size after transient focal cerebral ischemia in rats. Neuroscience 2004; 125:691-701. [PMID: 15099683 DOI: 10.1016/j.neuroscience.2004.02.034] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2004] [Indexed: 11/29/2022]
Abstract
Lidocaine is a local anesthetic and antiarrhythmic agent. Although clinical and experimental studies have shown that an antiarrhythmic dose of lidocaine can protect the brain from ischemic damage, the underlying mechanisms are unknown. In the present study, we examined whether lidocaine inhibits neuronal apoptosis in the penumbra in a rat model of transient focal cerebral ischemia. Male Wistar rats underwent a 90-min temporary occlusion of middle cerebral artery. Lidocaine was given as an i.v. bolus (1.5 mg/kg) followed by an i.v. infusion (2 mg/kg/h) for 180 min, starting 30 min before ischemia. Rats were killed and brain samples were collected at 4 and 24 h after ischemia. Apoptotic changes were evaluated by immunohistochemistry for cytochrome c release and caspase-3 activation and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) for DNA fragmentation. Cytochrome c release and caspase-3 activation were detected at 4 and 24 h after ischemia and DNA fragmentation was detected at 24 h. Double-labeling with NeuN, a neuronal marker, demonstrated that cytochrome c, caspase-3, and TUNEL were confined to neurons. Lidocaine reduced cytochrome c release and caspase-3 activation in the penumbra at 4 h and diminished DNA fragmentation in the penumbra at 24 h. Lidocaine treatment improved early electrophysiological recovery and reduced the size of the cortical infarct at 24 h, but had no significant effect on cerebral blood flow in either the penumbra or core during ischemia. These findings suggest that lidocaine attenuates apoptosis in the penumbra after transient focal cerebral ischemia. The infarct-reducing effects of lidocaine may be due, in part, to the inhibition of apoptotic cell death in the penumbra.
Collapse
Affiliation(s)
- B Lei
- Department of Anesthesiology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
| | | | | | | | | |
Collapse
|
25
|
Buenz EJ, Weaver JG, Bauer BA, Chalpin SD, Badley AD. Cordyceps sinensis extracts do not prevent Fas-receptor and hydrogen peroxide-induced T-cell apoptosis. JOURNAL OF ETHNOPHARMACOLOGY 2004; 90:57-62. [PMID: 14698509 DOI: 10.1016/j.jep.2003.09.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Aqueous and alcohol extracts of Cordyceps sinensis (Berk) Succ. are used as a traditional medicine in China for the treatment of a wide range of diseases and are reported to have antioxidant and antiapoptotic properties. We therefore examined the ability of aqueous, organic, and alcohol extracts of Cordyceps sinensis to inhibit apoptosis induced either by hydrogen peroxide or Fas-receptor ligation; both stimuli induce apoptosis dependent on reactive oxygen species. Cells pre-incubated with Cordyceps sinensis extracts were equally sensitive to hydrogen peroxide and Fas-mediated apoptosis. Thus, the putative antioxidant and antiapoptotic properties of Cordyceps sinensis are insufficient to rescue cells from apoptosis induced by these stimuli in vitro.
Collapse
Affiliation(s)
- E J Buenz
- Division of Infectious Diseases, Mayo Clinic and Foundation, Rochester, MN, USA
| | | | | | | | | |
Collapse
|
26
|
Yakovlev AG, Faden AI. Mechanisms of neural cell death: Implications for development of neuroprotective treatment strategies. Neurotherapeutics 2004. [DOI: 10.1007/bf03206563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
27
|
Candelario-Jalil E, González-Falcón A, García-Cabrera M, Álvarez D, Al-Dalain S, Martínez G, Sonia León O, Springer JE. Assessment of the relative contribution of COX-1 and COX-2 isoforms to ischemia-induced oxidative damage and neurodegeneration following transient global cerebral ischemia. J Neurochem 2003; 86:545-55. [PMID: 12859668 PMCID: PMC1636020 DOI: 10.1046/j.1471-4159.2003.01812.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We investigated the relative contribution of COX-1 and/or COX-2 to oxidative damage, prostaglandin E2 (PGE2) production and hippocampal CA1 neuronal loss in a model of 5 min transient global cerebral ischemia in gerbils. Our results revealed a biphasic and significant increase in PGE2 levels after 2 and 24-48 h of reperfusion. The late increase in PGE2 levels (24 h) was more potently reduced by the highly selective COX-2 inhibitor rofecoxib (20 mg/kg) relative to the COX-1 inhibitor valeryl salicylate (20 mg/kg). The delayed rise in COX catalytic activity preceded the onset of histopathological changes in the CA1 subfield of the hippocampus. Post-ischemia treatment with rofecoxib (starting 6 h after restoration of blood flow) significantly reduced measures of oxidative damage (glutathione depletion and lipid peroxidation) seen at 48 h after the initial ischemic episode, indicating that the late increase in COX-2 activity is involved in the delayed occurrence of oxidative damage in the hippocampus after global ischemia. Interestingly, either selective inhibition of COX-2 with rofecoxib or inhibition of COX-1 with valeryl salicylate significantly increased the number of healthy neurons in the hippocampal CA1 sector even when the treatment began 6 h after ischemia. These results provide the first evidence that both COX isoforms are involved in the progression of neuronal damage following global cerebral ischemia, and have important implications for the potential therapeutic use of COX inhibitors in cerebral ischemia.
Collapse
Affiliation(s)
| | - Armando González-Falcón
- Department of Pharmacology, University of Havana (CIEB-IFAL), Apartado Postal 6079, Havana City 10600, Cuba
| | - Michel García-Cabrera
- Department of Pharmacology, University of Havana (CIEB-IFAL), Apartado Postal 6079, Havana City 10600, Cuba
| | - Dalia Álvarez
- Department of Pharmacology, University of Havana (CIEB-IFAL), Apartado Postal 6079, Havana City 10600, Cuba
| | - Said Al-Dalain
- Department of Pharmacology, University of Havana (CIEB-IFAL), Apartado Postal 6079, Havana City 10600, Cuba
| | - Gregorio Martínez
- Department of Pharmacology, University of Havana (CIEB-IFAL), Apartado Postal 6079, Havana City 10600, Cuba
| | - Olga Sonia León
- Department of Pharmacology, University of Havana (CIEB-IFAL), Apartado Postal 6079, Havana City 10600, Cuba
| | - Joe E. Springer
- Department of Anatomy and Neurobiology, Spinal Cord and Brain Injury Research Center, University of Kentucky Medical Center, Lexington, KY 40536-0298, USA
| |
Collapse
|
28
|
Callaway JK, Lawrence AJ, Jarrott B. AM-36, a novel neuroprotective agent, profoundly reduces reactive oxygen species formation and dopamine release in the striatum of conscious rats after endothelin-1-induced middle cerebral artery occlusion. Neuropharmacology 2003; 44:787-800. [PMID: 12681377 DOI: 10.1016/s0028-3908(03)00068-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Elevated generation of reactive oxygen species (ROS) has been demonstrated during ischemia and reperfusion. Dopamine (DA) autooxidation may contribute to increased ROS generation. The novel neuroprotective agent AM-36 has antioxidant and Na(+) channel blocking activity and reduces neuronal damage in both cortex and striatum after middle cerebral artery (MCA) occlusion. Here we sought in vivo evidence of the ability of AM-36 to inhibit intrastriatal ROS generation and DA release after ischemia. Salicylate hydroxylation coupled with in vivo microdialysis in the striatum of conscious Long Evans rats was performed during MCA occlusion by perivascular microinjection of endothelin-1 (ET-1). AM-36 (6 mg/kg) was administered intraperitoneally 30 min after MCA occlusion. Dialysates were analysed using high performance liquid chromatography with electrochemical detection for the salicylate hydroxylation product, 2,3-dihydroxybenzoic acid (2,3 DHBA) and for DA and metabolites. MCA occlusion resulted in a marked increase in 2,3 DHBA and a secondary increase in all analytes, 180-300 min later. Increased DA release coincided with 2,3 DHBA formation. AM-36 significantly reduced ischemia induced increases in 2,3 DHBA and DA, and infarct volume in the striatum. Significant improvements in a battery of behavioural tests was also found in AM-36 treated rats. This study has demonstrated profound inhibition of ROS generation by a novel compound with antioxidant activity, administered post-ischemia in conscious rats.
Collapse
Affiliation(s)
- J K Callaway
- Department of Pharmacology, PO Box 13E, Monash University, Clayton, Victoria 3800, Australia.
| | | | | |
Collapse
|
29
|
Vink R, Nimmo AJ. Novel therapies in development for the treatment of traumatic brain injury. Expert Opin Investig Drugs 2002; 11:1375-86. [PMID: 12387701 DOI: 10.1517/13543784.11.10.1375] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In industrialised countries, the mean per capita incidence of traumatic brain injury (TBI) that results in a hospital presentation is 250 per 100,000. In Europe and North America alone, this translates to > 2 million TBI presentations annually. Approximately 25% of these presentations are admitted for hospitalisation. Despite the significance of these figures, there is no single interventional pharmacotherapy that has shown efficacy in the treatment of clinical TBI. This lack of efficacy in clinical trials may be due, in part, to the inherent heterogeneity of the traumatic brain injury population. However, it is the multifactorial nature of secondary injury that also poses a major hurdle, particularly for those therapies that have been designed to specifically target an individual injury factor. It is now becoming increasingly recognised that any successful TBI therapy may have to simultaneously affect multiple injury factors, somewhat analogous to other broad spectrum interventions. Recent efforts in experimental TBI have therefore focussed on developing novel pharmacotherapies that may affect multiple injury factors and thus improve the likelihood of a successful outcome. While a number of interventions are noteworthy in this regard, this review will focus on three novel compounds that show particular promise: magnesium, substance P antagonists and cyclosporin A.
Collapse
Affiliation(s)
- Robert Vink
- Department of Pathology, The University of Adelaide, South Australia, Australia.
| | | |
Collapse
|
30
|
Wang X, Mori T, Sumii T, Lo EH. Hemoglobin-induced cytotoxicity in rat cerebral cortical neurons: caspase activation and oxidative stress. Stroke 2002; 33:1882-8. [PMID: 12105370 DOI: 10.1161/01.str.0000020121.41527.5d] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Apoptotic-like pathways may contribute to brain cell death after intracerebral hemorrhage. In this study, we used a simplified in vitro model of hemoglobin neurotoxicity to map the caspase cascades involved and to document the role of oxidative stress. METHODS Primary neuronal cultures were obtained from rat cerebral cortex and exposed to hemoglobin to induce cell death. Cytotoxicity was assessed via measurements of mitochondrial viability (MTT assay) and lactate dehydrogenase (LDH assay). Activation of caspase-3, -8, and -9 was measured by Western blot and enzyme activity assays. Various caspase inhibitors (zVADfmk, zDEVDfmk, zIETDfmk, and zLEHDfmk) were tested for neuroprotective efficacy. The role of oxidative stress was assessed with the use of U83836E as a potent scavenger of free radicals. RESULTS Exposure of primary cortical neurons to hemoglobin induced a dose- and time-dependent cytotoxicity. Western blots showed upregulation of cleaved caspase-3. Enzyme assays showed an increase in caspase-9-like and caspase-3-like activity. However, caspase inhibition did not result in neuroprotection. In contrast, the free radical scavenger U83836E significantly reduced hemoglobin-induced neuronal death. Combination treatment with both U83836E and the broad spectrum caspase inhibitor zVADfmk did not yield additional protection. CONCLUSIONS Upstream and downstream caspases were upregulated after hemoglobin-induced neurotoxicity in vitro, but only an antioxidant approach with a potent free radical scavenger significantly improved neuronal survival. These data suggest that in addition to the activation of caspase cascades, parallel pathways of oxidative stress may predominate in this model of hemoglobin neurotoxicity.
Collapse
Affiliation(s)
- Xiaoying Wang
- Neuroprotection Research Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Mass 02129, USA.
| | | | | | | |
Collapse
|
31
|
Tabakman R, Lazarovici P, Kohen R. Neuroprotective effects of carnosine and homocarnosine on pheochromocytoma PC12 cells exposed to ischemia. J Neurosci Res 2002; 68:463-9. [PMID: 11992473 DOI: 10.1002/jnr.10228] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The development of neuroprotective drugs against ischemic insults is hampered by the lack of pharmacological in vitro models. We developed an ischemic model using PC12 cell cultures exposed to oxygen-glucose-deprivation (OGD) followed by reoxygenation (18 hr) under regular atmospheric oxygen level. The toxicity induced in this model, that is partially caused by generation of reactive oxygen species (ROS), was measured morphologically as well as by the release of lactate dehydrogenase (LDH) and the prostaglandin PGE(2) from the cells. Carnosine and homocarnosine, histidine dipeptides antioxidants, found in high concentration in the brain, have been suggested to provide neuroprotection. Using the OGD model we found that 5 mM carnosine and 1 mM homocarnosine provided maximal neuroprotection of about 50% against OGD insult. This neuroprotective effect was similar to that of a known antioxidant, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol), and was not observed in a serum-deprivation toxicity model of PC12 cells, indicating that carnosine and homocarnosine may act as antioxidant-neuroprotective agents in the brain. Our ischemic model may provide a useful tool for investigating the mechanisms involved in the neuroprotection afforded by histidine dipeptides.
Collapse
Affiliation(s)
- Rinat Tabakman
- Department of Pharmacology and Experimental Therapeutics, Hebrew University of Jerusalem, Jerusalem, Israel
| | | | | |
Collapse
|
32
|
Halliwell B. Role of free radicals in the neurodegenerative diseases: therapeutic implications for antioxidant treatment. Drugs Aging 2002; 18:685-716. [PMID: 11599635 DOI: 10.2165/00002512-200118090-00004] [Citation(s) in RCA: 1011] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Free radicals and other so-called 'reactive species' are constantly produced in the brain in vivo. Some arise by 'accidents of chemistry', an example of which may be the leakage of electrons from the mitochondrial electron transport chain to generate superoxide radical (O2*-). Others are generated for useful purposes, such as the role of nitric oxide in neurotransmission and the production of O2*- by activated microglia. Because of its high ATP demand, the brain consumes O2 rapidly, and is thus susceptible to interference with mitochondrial function, which can in turn lead to increased O2*- formation. The brain contains multiple antioxidant defences, of which the mitochondrial manganese-containing superoxide dismutase and reduced glutathione seem especially important. Iron is a powerful promoter of free radical damage, able to catalyse generation of highly reactive hydroxyl, alkoxyl and peroxyl radicals from hydrogen peroxide and lipid peroxides, respectively. Although most iron in the brain is stored in ferritin, 'catalytic' iron is readily mobilised from injured brain tissue. Increased levels of oxidative damage to DNA, lipids and proteins have been detected by a range of assays in post-mortem tissues from patients with Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis, and at least some of these changes may occur early in disease progression. The accumulation and precipitation of proteins that occur in these diseases may be aggravated by oxidative damage, and may in turn cause more oxidative damage by interfering with the function of the proteasome. Indeed, it has been shown that proteasomal inhibition increases levels of oxidative damage not only to proteins but also to other biomolecules. Hence, there are many attempts to develop antioxidants that can cross the blood-brain barrier and decrease oxidative damage. Natural antioxidants such as vitamin E (tocopherol), carotenoids and flavonoids do not readily enter the brain in the adult, and the lazaroid antioxidant tirilazad (U-74006F) appears to localise in the blood-brain barrier. Other antioxidants under development include modified spin traps and low molecular mass scavengers of O2*-. One possible source of lead compounds is the use of traditional remedies claimed to improve brain function. Little is known about the impact of dietary antioxidants upon the development and progression of neurodegenerative diseases, especially Alzheimer's disease. Several agents already in therapeutic use might exert some of their effects by antioxidant action, including selegiline (deprenyl), apomorphine and nitecapone.
Collapse
Affiliation(s)
- B Halliwell
- Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore.
| |
Collapse
|
33
|
Contestabile A. Cerebellar granule cells as a model to study mechanisms of neuronal apoptosis or survival in vivo and in vitro. CEREBELLUM (LONDON, ENGLAND) 2002; 1:41-55. [PMID: 12879973 DOI: 10.1080/147342202753203087] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Granule cells of the cerebellum constitute the largest homogeneous neuronal population of mammalian brain. Due to their postnatal generation and the feasibility of well characterized primary in vitro cultures, cerebellar granule cells are a model of election for the study of cellular and molecular correlates of mechanisms of survival/apoptosis and neurodegeneration/neuroprotection. The present review mainly deals with recent data on mechanisms and factors promoting survival or apoptotic elimination of cerebellar granule neurons, with a particular focus on the molecular correlates at the level of gene expression and induction of cellular signal pathways. The in vivo development is first analysed with particular reference to the role played by several neurotrophic factors and by the NMDA subtype of glutamate receptor. Then, mechanisms of survival/apoptosis are examined in the model of primary in vitro cultures, where the role of neurotrophins acting on cerebellar granule cells is followed by the large deal of data coming from the paradigm of potassium/serum withdrawal. The role of some key genes of the Bcl family, of some kinase systems and of transcriptional factors is primarily highlighted. Furthermore, the involvement of mitochondria, free radicals and proteases of the caspase family is considered. Finally, the use of cerebellar granule neurons in primary culture to experimentally address the issue of neurodegeneration and pharmacological neuroprotection is considered, with some comments on models at the borderline between necrosis and apoptosis, such as the excitotoxic neuronal damage. The overlapping of cellular signal pathways activated in granule neurons by apparently unrelated stimuli, such as neurotrophins and neurotransmitters/neuromodulators is stressed to put into light the special 'trophic' role played by activity in neurons. Finally, the advantage of designing and performing conceptually equivalent experiments on cerebellar granule neurons during development in vivo and in vitro, is stressed. On the basis of the reviewed material, it is concluded that cerebellar granule neurons have acquired a special position in modern neuroscience as one of the most reliable models for the study of neural development, function and pathology.
Collapse
|
34
|
Abstract
1. The neurochemical sequelae following cerebral ischaemia are complex, involving excess release of excitatory amino acids, particularly glutamate, disruption of ionic homeostasis due to Na+ and Ca2+ influx and generation of toxic free radicals, ultimately leading to cell death by both necrosis and apoptosis. 2. Drugs that block components of this biochemical cascade, such as glutamate receptor antagonists, sodium channel blockers and free radical scavengers, have been investigated as putative neuroprotective agents. The knowledge that multiple mechanisms contribute to neuronal injury in ischaemia have led to the general recognition that a single drug treatment is unlikely to be beneficial in the treatment of cerebral ischaemia. 3. AM-36 [1-(2-(4-chlorophenyl)-2-hydroxy)ethyl-4-(3,5-bis(1,1-dimethyl)-4-hydroxyphenyl)methylpiperazine] is one of a series of hybrid molecules designed to incorporate multiple neuroprotective mechanisms within the one structure. Primary screening tests demonstrated that AM-36 inhibited binding to the polyamine site of glutamate receptors, blocked neuronal sodium channels and had potent anti-oxidant activity. In neuronal cell cultures, AM-36 inhibited toxicity induced by N-methyl-D-aspartate (NMDA) and the sodium channel opener veratridine and, in addition, inhibited veratridine-induced apoptosis. 4. In a middle cerebral artery occlusion model of stroke in conscious rats, systemic administration of AM-36 markedly reduced both cortical and striatal infarct volume and significantly improved functional outcome in motor performance, neurological deficit and sensorimotor neglect tests. AM-36 was neuroprotective even when administration was delayed until 3 h systemically, or 5 h intravenously, after induction of stroke. 5. These studies indicate that AM-36 is a unique neuroprotective agent with multiple modes of action, making it an attractive candidate for the treatment of acute stroke in humans.
Collapse
Affiliation(s)
- J K Callaway
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia.
| |
Collapse
|