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Erythrina variegata L. bark: an untapped bioactive source harbouring therapeutic properties for the treatment of Alzheimer's disease. In Silico Pharmacol 2021; 9:51. [PMID: 34532215 DOI: 10.1007/s40203-021-00110-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022] Open
Abstract
A critical approach for target identification to detect the significant molecular mechanism of lead molecules via computational methods combined with in vitro procedures defines the modern strategy to combat untreatable diseases. Hence, the present investigation dealt to determine the effect of Erythrina variegata L. bark extract/fraction(s) over acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity followed by target identification and docking analysis of prime phytoconstituents. The in vitro AChE and BChE enzyme inhibitory assay were performed. Phytoconstituents from E. variegata were screened for carcinogenicity and mutagenicity and predicted for their possible targets leading to the identification of two known targets, i.e. AChE and BChE. The alkaloids with non-carcinogenic and non-mutagenic properties were studied for their main moiety responsible for the inhibitory activity. The protein models were checked in ERRAT for their quality and the homology model was created using Modeller9.10v to fill missing amino acid residues. The docking study predicted the binding affinity of bioactive molecules with identified targets using AutoDock 4.2. Molecular dynamics (MD) simulations for top hits were performed by Schrodinger Desmond 6.1v software. Chloroform fraction showed potent inhibition of AChE and BChE with IC50 value of 38.03 ± 1.987 µg/mL and 20.67 ± 2.794 µg/mL, respectively. Among all the six major bioactive compounds, Erysotine and Erythraline scored the highest binding affinity with AChE and Erysodine with BChE. MD simulation for 20 ns production run demonstrated Erysotine and Erysodine stable interaction with Arg49 of AChE and Lys427 of BChE, respectively. The current data provide enough shreds of evidence supporting the utilization of indolo [7a,1-a] isoquinoline derivatives for the identification of a new drug molecule in the management of Alzheimer's disease. Supplementary Information The online version contains supplementary material available at 10.1007/s40203-021-00110-0.
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Moss DE. Improving Anti-Neurodegenerative Benefits of Acetylcholinesterase Inhibitors in Alzheimer's Disease: Are Irreversible Inhibitors the Future? Int J Mol Sci 2020; 21:E3438. [PMID: 32414155 PMCID: PMC7279429 DOI: 10.3390/ijms21103438] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/01/2020] [Accepted: 05/11/2020] [Indexed: 02/06/2023] Open
Abstract
Decades of research have produced no effective method to prevent, delay the onset, or slow the progression of Alzheimer's disease (AD). In contrast to these failures, acetylcholinesterase (AChE, EC 3.1.1.7) inhibitors slow the clinical progression of the disease and randomized, placebo-controlled trials in prodromal and mild to moderate AD patients have shown AChE inhibitor anti-neurodegenerative benefits in the cortex, hippocampus, and basal forebrain. CNS neurodegeneration and atrophy are now recognized as biomarkers of AD according to the National Institute on Aging-Alzheimer's Association (NIA-AA) criteria and recent evidence shows that these markers are among the earliest signs of prodromal AD, before the appearance of amyloid. The current AChE inhibitors (donepezil, rivastigmine, and galantamine) have short-acting mechanisms of action that result in dose-limiting toxicity and inadequate efficacy. Irreversible AChE inhibitors, with a long-acting mechanism of action, are inherently CNS selective and can more than double CNS AChE inhibition possible with short-acting inhibitors. Irreversible AChE inhibitors open the door to high-level CNS AChE inhibition and improved anti-neurodegenerative benefits that may be an important part of future treatments to more effectively prevent, delay the onset, or slow the progression of AD.
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Affiliation(s)
- Donald E Moss
- Department of Psychology, University of Texas at El Paso, El Paso, TX 79968, USA
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El-Sayed NF, El-Hussieny M, Ewies EF, Fouad MA, Boulos LS. New phosphazine and phosphazide derivatives as multifunctional ligands targeting acetylcholinesterase and β-Amyloid aggregation for treatment of Alzheimer's disease. Bioorg Chem 2019; 95:103499. [PMID: 31838287 DOI: 10.1016/j.bioorg.2019.103499] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 12/26/2022]
Abstract
Phosphazine and phosphazide derivatives are described herein as a new class of selective and potent acetylcholinesterase (AChE) inhibitors and β-amyloid aggregation inhibitors. Phosphazines (5-7) were synthesized smoothly via a redox-condensation reaction of 1,2-bis(diphenylphosphino)ethane with different amines derivatives in the presence of dialkyl azodicarboxylate (Staudinger reaction) while phosphazides (8) via electrophilic attack of azido derivatives. Structures of the synthesized compounds were justified on the basis of compatible elementary and spectroscopic analyses. All the compounds were evaluated for their acetylcholinesterase inhibitory activity. The most three potent compounds (5b-c and 8b) showing AChE IC50 values (29.85-34.96 nM) comparable to that of donepezil (34.42 nM) were subjected to further investigation by testing their butyrylcholinesterase, MMP-2 and self-induced Aβ aggregation inhibition activity. Especially, the coumarin phosphazide derivative (8b) presented the best AChE inhibition selectivity index (IC50 = 34.96 nM, AChE/BuChE; 3.81) together with good inhibition ability against MMP-2 (IC50 = 441.33 nM) and self-induced Aβ1-42 aggregation (IC50 = 337.77 nM). In addition, the inhibition of metal-induced Aβ aggregation by 8b was confirmed by thioflavine T fluorescence. The most potent effect of 8b was observed on the Zn2+-induced Aβ42 aggregation. Kinetic study of compound 8b suggested it to be a competitive AChE inhibitor. Also, it specifically chelates metal and is predicted to be permeable to BBB. It also possesses low toxicity on SH-SY5Y neuroblastoma cells with a safety index of 15.37. In addition, it was demonstrated that compound 8b can improve the cognitive impairment of scopolamine-induced model in mice with % alternations and transfer latency time comparable to that of donepezil. Also, a docking study was carried out and it was in accordance with the in vitro results. These promising in vitro and in vivo findings highlight compound 8b as a possible drug candidate in searching for new multifunctional AD drugs.
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Affiliation(s)
- Naglaa F El-Sayed
- Organometallic and Organometalloid Chemistry Department, National Research Centre, 33 ElBohouth St., (Former El Tahrir) Dokki, P.O. 12622, Giza, Egypt
| | - Marwa El-Hussieny
- Organometallic and Organometalloid Chemistry Department, National Research Centre, 33 ElBohouth St., (Former El Tahrir) Dokki, P.O. 12622, Giza, Egypt
| | - Ewies F Ewies
- Organometallic and Organometalloid Chemistry Department, National Research Centre, 33 ElBohouth St., (Former El Tahrir) Dokki, P.O. 12622, Giza, Egypt.
| | - Marwa A Fouad
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini St., Cairo 11562, Egypt.
| | - Leila S Boulos
- Organometallic and Organometalloid Chemistry Department, National Research Centre, 33 ElBohouth St., (Former El Tahrir) Dokki, P.O. 12622, Giza, Egypt
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Biphenyl-3-oxo-1,2,4-triazine linked piperazine derivatives as potential cholinesterase inhibitors with anti-oxidant property to improve the learning and memory. Bioorg Chem 2019; 85:82-96. [DOI: 10.1016/j.bioorg.2018.12.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 12/03/2018] [Accepted: 12/12/2018] [Indexed: 12/13/2022]
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Chen T, Tan J, Wan Z, Zou Y, Afewerky HK, Zhang Z, Zhang T. Effects of Commonly Used Pesticides in China on the Mitochondria and Ubiquitin-Proteasome System in Parkinson's Disease. Int J Mol Sci 2017; 18:ijms18122507. [PMID: 29168786 PMCID: PMC5751110 DOI: 10.3390/ijms18122507] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/12/2017] [Accepted: 11/20/2017] [Indexed: 02/08/2023] Open
Abstract
Evidence continues to accumulate that pesticides are the leading candidates of environmental toxins that may contribute to the pathogenesis of Parkinson’s disease. The mechanisms, however, remain largely unclear. According to epidemiological studies, we selected nine representative pesticides (paraquat, rotenone, chlorpyrifos, pendimethalin, endosulfan, fenpyroximate, tebufenpyrad, trichlorphon and carbaryl) which are commonly used in China and detected the effects of the pesticides on mitochondria and ubiquitin-proteasome system (UPS) function. Our results reveal that all the nine studied pesticides induce morphological changes of mitochondria at low concentrations. Paraquat, rotenone, chlorpyrifos, pendimethalin, endosulfan, fenpyroximate and tebufenpyrad induced mitochondria fragmentation. Furthermore, some of them (paraquat, rotenone, chlorpyrifos, fenpyroximate and tebufenpyrad) caused a significant dose-dependent decrease of intracellular ATP. Interestingly, these pesticides which induce mitochondria dysfunction also inhibit 26S and 20S proteasome activity. However, two out of the nine pesticides, namely trichlorphon and carbaryl, were found not to cause mitochondrial fragmentation or functional damage, nor inhibit the activity of the proteasome, which provides significant guidance for selection of pesticides in China. Moreover, our results demonstrate a potential link between inhibition of mitochondria and the UPS, and pesticide-induced Parkinsonism.
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Affiliation(s)
- Tingting Chen
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha 410078, China.
| | - Jieqiong Tan
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha 410078, China.
| | - Zhengqing Wan
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha 410078, China.
| | - Yongyi Zou
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha 410078, China.
| | - Henok Kessete Afewerky
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha 410078, China.
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
- The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Zhuohua Zhang
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha 410078, China.
| | - Tongmei Zhang
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha 410078, China.
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
- The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan 430030, China.
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Ramsay RR, Tipton KF. Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs. Molecules 2017; 22:E1192. [PMID: 28714881 PMCID: PMC6152246 DOI: 10.3390/molecules22071192] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 11/16/2022] Open
Abstract
The actions of many drugs involve enzyme inhibition. This is exemplified by the inhibitors of monoamine oxidases (MAO) and the cholinsterases (ChE) that have been used for several pharmacological purposes. This review describes key principles and approaches for the reliable determination of enzyme activities and inhibition as well as some of the methods that are in current use for such studies with these two enzymes. Their applicability and potential pitfalls arising from their inappropriate use are discussed. Since inhibitor potency is frequently assessed in terms of the quantity necessary to give 50% inhibition (the IC50 value), the relationships between this and the mode of inhibition is also considered, in terms of the misleading information that it may provide. Incorporation of more than one functionality into the same molecule to give a multi-target-directed ligands (MTDLs) requires careful assessment to ensure that the specific target effects are not significantly altered and that the kinetic behavior remains as favourable with the MTDL as it does with the individual components. Such factors will be considered in terms of recently developed MTDLs that combine MAO and ChE inhibitory functions.
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Affiliation(s)
- Rona R Ramsay
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews KY16 8QP, UK.
| | - Keith F Tipton
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland.
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Moss DE, Perez RG, Kobayashi H. Cholinesterase Inhibitor Therapy in Alzheimer's Disease: The Limits and Tolerability of Irreversible CNS-Selective Acetylcholinesterase Inhibition in Primates. J Alzheimers Dis 2017; 55:1285-1294. [PMID: 27858711 DOI: 10.3233/jad-160733] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Irreversible acetylcholinesterase (AChE) inhibition accumulates to high levels in the central nervous system (CNS) because AChE turnover in the brain is much slower than in peripheral tissues. As expected from this CNS selectivity, the irreversible AChE inhibitor methanesulfonyl fluoride (MSF) produces significant cognitive improvement in Alzheimer's disease patients without the gastrointestinal toxicity that plagues other AChE inhibitors. However, without dose-limiting gastrointestinal toxicity, one shortcoming of the prior human studies of MSF is that the upper limits of CNS AChE inhibition that might be tolerated could not be tested. Therefore, in this study, monkeys were treated with escalating intramuscular (IM) doses of MSF that culminated with several weeks of 1.5 mg/kg dosing, more than eight times the prior human clinical dose, still without signs of toxicity. Brain biopsies showed that ∼80% AChE inhibition had been produced and that the new synthesis of cortical AChE had a half-time (t1/2) of ∼12 days. A single IM dose of 1.5 mg/kg MSF produced ∼59% inhibition in cerebrospinal fluid (CSF) AChE as measured one day later. This corresponds to a peak of ∼80% inhibition in CSF AChE at the time of the injection, recovering with a t1/2 of 2.4 days. Computational analyses suggest that MSF at clinically relevant doses could theoretically produce a steady-state AChE inhibition between 65% and 85% in the CNS. These data suggest that the full therapeutic advantage of AChE inhibition therapy can be realized without interference from dose-limiting gastrointestinal toxicity if an irreversible inhibitor is employed.
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Affiliation(s)
- Donald E Moss
- Department of Psychology, University of Texas at El Paso, El Paso, TX, USA
| | - Ruth G Perez
- Department of Biomedical Sciences, Center of Emphasis in Neurosciences, Graduate School of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University of the Health Sciences El Paso, El Paso, TX, USA
| | - Haruo Kobayashi
- Department of Veterinary Pharmacology, Iwate University, Ueda, Morioka, Japan
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Keiser J, Panic G, Adelfio R, Cowan N, Vargas M, Scandale I. Evaluation of an FDA approved library against laboratory models of human intestinal nematode infections. Parasit Vectors 2016; 9:376. [PMID: 27363703 PMCID: PMC4929775 DOI: 10.1186/s13071-016-1616-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 06/01/2016] [Indexed: 01/13/2023] Open
Abstract
Background Treatment options for infections with soil-transmitted helminths (STH) - Ascaris lumbricoides, Trichuris trichiura and the two hookworm species, Ancylostoma duodenale and Necator americanus - are limited despite their considerable global health burden. The aim of the present study was to test the activity of an openly available FDA library against laboratory models of human intestinal nematode infections. Methods All 1,600 drugs were first screened against Ancylostoma ceylanicum third-stage larvae (L3). Active compounds were scrutinized and toxic compounds, drugs indicated solely for topical use, and already well-studied anthelmintics were excluded. The remaining hit compounds were tested in parallel against Trichuris muris first-stage larvae (L1), Heligmosomoides polygyrus third-stage larvae (L3), and adult stages of the three species in vitro. In vivo studies were performed in the H. polygyrus and T. muris mice models. Results Fifty-four of the 1,600 compounds tested revealed an activity of > 60 % against A. ceylanicum L3 (hit rate of 3.4 %), following incubation at 200 μM for 72 h. Twelve compounds progressed into further screens. Adult A. ceylanicum were the least affected (1/12 compounds active at 50 μM), while eight of the 12 test compounds revealed activity against T. muris L1 (100 μM) and adults (50 μM), and H. polygyrus L3 (200 μM). Trichlorfon was the only compound active against all stages of A. ceylanicum, H. polygyrus and T. muris. In addition, trichlorfon achieved high worm burden reductions of 80.1 and 98.9 %, following a single oral dose of 200 mg/kg in the T. muris and H. polygyrus mouse model, respectively. Conclusion Drug screening on the larval stages of intestinal parasitic nematodes is feasible using small libraries and important given the empty drug discovery and development pipeline for STH infections. Differences and commonalities in drug activities across the different STH species and stages were confirmed. Hits identified might serve as a starting point for drug discovery for STH. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1616-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Gordana Panic
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Roberto Adelfio
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Noemi Cowan
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Mireille Vargas
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Ivan Scandale
- Drugs for Neglected Disease initiative, Chemin Louis-Dunant 15, 1202, Genève, Switzerland
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Laver K, Dyer S, Whitehead C, Clemson L, Crotty M. Interventions to delay functional decline in people with dementia: a systematic review of systematic reviews. BMJ Open 2016; 6:e010767. [PMID: 27121704 PMCID: PMC4854009 DOI: 10.1136/bmjopen-2015-010767] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE To summarise existing systematic reviews that assess the effects of non-pharmacological, pharmacological and alternative therapies on activities of daily living (ADL) function in people with dementia. DESIGN Overview of systematic reviews. METHODS A systematic search in the Cochrane Database of Systematic Reviews, DARE, Medline, EMBASE and PsycInfo in April 2015. Systematic reviews of randomised controlled trials conducted in people with Alzheimer's disease or dementia measuring the impact on ADL function were included. Methodological quality of the systematic reviews was independently assessed by two authors using the AMSTAR tool. The quality of evidence of the primary studies for each intervention was assessed using GRADE. RESULTS A total of 23 systematic reviews were included in the overview. The quality of the reviews varied; however most (65%) scored 8/11 or more on the AMSTAR tool, indicating high quality. Interventions that were reported to be effective in minimising decline in ADL function were: exercise (6 studies, 289 participants, standardised mean difference (SMD) 0.68, 95% CI 0.08 to 1.27; GRADE: low), dyadic interventions (8 studies, 988 participants, SMD 0.37, 95% CI 0.05 to 0.69; GRADE: low) acetylcholinesterase inhibitors and memantine (12 studies, 4661 participants, donepezil 10 mg SMD 0.18, 95% CI 0.03 to 0.32; GRADE: moderate), selegiline (7 studies, 810 participants, SMD 0.27, 95% CI 0.13 to 0.41; GRADE: low), huperzine A (2 studies, 70 participants, SMD 1.48, 95% CI 0.95 to 2.02; GRADE: very low) and Ginkgo biloba (7 studies, 2530 participants, SMD 0.36, 95% CI 0.28 to 0.44; GRADE: very low). CONCLUSIONS Healthcare professionals should ensure that people with dementia are encouraged to exercise and that primary carers are trained and supported to provide safe and effective care for the person with dementia. Acetylcholinesterase inhibitors or memantine should be trialled unless contraindicated. TRIAL REGISTRATION NUMBER CRD42015020179.
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Affiliation(s)
- Kate Laver
- Department of Rehabilitation, Aged and Extended Care, Flinders University, Adelaide, South Australia, Australia
| | - Suzanne Dyer
- Department of Rehabilitation, Aged and Extended Care, Flinders University, Adelaide, South Australia, Australia
| | - Craig Whitehead
- Department of Rehabilitation, Aged and Extended Care, Flinders University, Adelaide, South Australia, Australia
| | - Lindy Clemson
- Ageing, Work and Health Research Unit, University of Sydney, Sydney, New South Wales, Australia
| | - Maria Crotty
- Department of Rehabilitation, Aged and Extended Care, Flinders University, Adelaide, South Australia, Australia
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Benavides-González F, Gomez-Flores RA, Rábago-Castro JL, Sánchez-Martínez JG, Montelongo-Alfaro IO. Effects of Hydrogen Peroxide and Metrifonate on Monogenean ligictaluridus floridanus on Catfish ( Ictalurus punctatus , Rafinesque) Gills. J Parasitol 2015; 101:707-10. [PMID: 26286108 DOI: 10.1645/15-791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Hydrogen peroxide (H2O2) and metrifonate (Mtf) are common products used in ectoparasite infestations on fish cultures. The therapeutic efficacy of H2O2 and Mtf on a common monogenean parasite, Ligictaluridus floridanus, was evaluated in channel catfish ( Ictalurus punctatus ). In vitro trials were conducted using excised fish gills naturally infected with L. floridanus, which were immersed in H2O2 (150, 300, and 570 mg L(-1)) and Mtf (0.25, 0.5, and 0.75 mg L(-1)) solutions. The efficacy of the treatments was based on the survival time of the parasites, observed microscopically. In addition, an in vivo trial using catfish juveniles, naturally infected with L. floridanus, was also performed. One group received immersion baths of 570 mg L(-1) H2O2 (3%) during 4 min; the Mtf (90%) group received 0.5 mg L(-1) Mtf for 10 min. Treatments were done on days 3, 7, and 11 of the experiment. Results indicate that baths with Mtf do not significantly reduce the mean intensity of the parasite per gill arch, nor do they reduce the in vitro survival time of parasites during treatment; H2O2 baths at 570 mg L(-1) during 4 min were effective (P < 0.05) against adult and juvenile stages of L. floridanus. This study supports the use of H2O2 as an effective antiparasitic agent against I. punctatus .
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Affiliation(s)
- Flaviano Benavides-González
- Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Pedro de Alba s/n, San Nicolás de Los Garza, Nuevo León, México. Z. C. 66450
| | - Ricardo Alberto Gomez-Flores
- Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Pedro de Alba s/n, San Nicolás de Los Garza, Nuevo León, México. Z. C. 66450
| | - Jaime Luis Rábago-Castro
- Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Pedro de Alba s/n, San Nicolás de Los Garza, Nuevo León, México. Z. C. 66450
| | - Jesús Genaro Sánchez-Martínez
- Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Pedro de Alba s/n, San Nicolás de Los Garza, Nuevo León, México. Z. C. 66450
| | - Isidro Otoniel Montelongo-Alfaro
- Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Pedro de Alba s/n, San Nicolás de Los Garza, Nuevo León, México. Z. C. 66450
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Pohanka M. Inhibitors of acetylcholinesterase and butyrylcholinesterase meet immunity. Int J Mol Sci 2014; 15:9809-25. [PMID: 24893223 PMCID: PMC4100123 DOI: 10.3390/ijms15069809] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/06/2014] [Accepted: 03/11/2014] [Indexed: 12/22/2022] Open
Abstract
Acetylcholinesterase (AChE) inhibitors are widely used for the symptomatic treatment of Alzheimer’s disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE). Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a “cholinergic anti-inflammatory pathway” which raises questions about the role of these inhibitors in the immune system. This review covers research and discussion of the role of the inhibitors in modulating the immune response using as examples the commonly available drugs, donepezil, galantamine, huperzine, neostigmine and pyridostigmine. Major attention is given to the cholinergic anti-inflammatory pathway, a well-described link between the central nervous system and terminal effector cells in the immune system.
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Affiliation(s)
- Miroslav Pohanka
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove CZ-50001, Czech Republic.
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12
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Redolfi A, Bosco P, Manset D, Frisoni GB. Brain investigation and brain conceptualization. FUNCTIONAL NEUROLOGY 2014; 28:175-90. [PMID: 24139654 DOI: 10.11138/fneur/2013.28.3.175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The brain of a patient with Alzheimer's disease (AD) undergoes changes starting many years before the development of the first clinical symptoms. The recent availability of large prospective datasets makes it possible to create sophisticated brain models of healthy subjects and patients with AD, showing pathophysiological changes occurring over time. However, these models are still inadequate; representations are mainly single-scale and they do not account for the complexity and interdependence of brain changes. Brain changes in AD patients occur at different levels and for different reasons: at the molecular level, changes are due to amyloid deposition; at cellular level, to loss of neuron synapses, and at tissue level, to connectivity disruption. All cause extensive atrophy of the whole brain organ. Initiatives aiming to model the whole human brain have been launched in Europe and the US with the goal of reducing the burden of brain diseases. In this work, we describe a new approach to earlier diagnosis based on a multimodal and multiscale brain concept, built upon existing and well-characterized single modalities.
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Schneider LS, Mangialasche F, Andreasen N, Feldman H, Giacobini E, Jones R, Mantua V, Mecocci P, Pani L, Winblad B, Kivipelto M. Clinical trials and late-stage drug development for Alzheimer's disease: an appraisal from 1984 to 2014. J Intern Med 2014; 275:251-83. [PMID: 24605808 PMCID: PMC3956752 DOI: 10.1111/joim.12191] [Citation(s) in RCA: 481] [Impact Index Per Article: 48.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The modern era of drug development for Alzheimer's disease began with the proposal of the cholinergic hypothesis of memory impairment and the 1984 research criteria for Alzheimer's disease. Since then, despite the evaluation of numerous potential treatments in clinical trials, only four cholinesterase inhibitors and memantine have shown sufficient safety and efficacy to allow marketing approval at an international level. Although this is probably because the other drugs tested were ineffective, inadequate clinical development methods have also been blamed for the failures. Here, we review the development of treatments for Alzheimer's disease during the past 30 years, considering the drugs, potential targets, late-stage clinical trials, development methods, emerging use of biomarkers and evolution of regulatory considerations in order to summarize advances and anticipate future developments. We have considered late-stage Alzheimer's disease drug development from 1984 to 2013, including individual clinical trials, systematic and qualitative reviews, meta-analyses, methods, commentaries, position papers and guidelines. We then review the evolution of drugs in late clinical development, methods, biomarkers and regulatory issues. Although a range of small molecules and biological products against many targets have been investigated in clinical trials, the predominant drug targets have been the cholinergic system and the amyloid cascade. Trial methods have evolved incrementally: inclusion criteria have largely remained focused on mild-to-moderate Alzheimer's disease criteria, recently extending to early or prodromal Alzheimer disease or 'mild cognitive impairment due to Alzheimer's disease', for drugs considered to be disease modifying. The duration of trials has remained at 6-12 months for drugs intended to improve symptoms; 18- to 24-month trials have been established for drugs expected to attenuate clinical course. Cognitive performance, activities of daily living, global change and severity ratings have persisted as the primary clinically relevant outcomes. Regulatory guidance and oversight have evolved to allow for enrichment of early-stage Alzheimer's disease trial samples using biomarkers and phase-specific outcomes. In conclusion, validated drug targets for Alzheimer's disease remain to be developed. Only drugs that affect an aspect of cholinergic function have shown consistent, but modest, clinical effects in late-phase trials. There is opportunity for substantial improvements in drug discovery and clinical development methods.
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Affiliation(s)
- Lon S. Schneider
- Departments of Psychiatry and the Behavioral Sciences, and Neurology, Keck School of Medicine, and the Leonard Davis School of Gerontology of the University of Southern California, Los Angeles, CA, USA
| | - Francesca Mangialasche
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- Section of Gerontology and Geriatrics, University of Perugia, Perugia, Italy
| | - Niels Andreasen
- Department of Geriatric Medicine, Karolinska University Hospital, Huddinge, Sweden
- Alzheimer Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Howard Feldman
- Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Ezio Giacobini
- Departments of Internal Medicine, Rehabilitation and Geriatrics, University of Geneva Hospitals, Geneva, Switzerland
| | - Roy Jones
- The Research Institute for the Care of Older People (RICE) and University of Bath, Bath, UK
| | - Valentina Mantua
- European Assessment Office, Italian Medicines Agency (AIFA), Rome, Italy
| | - Patrizia Mecocci
- Section of Gerontology and Geriatrics, University of Perugia, Perugia, Italy
| | - Luca Pani
- European Assessment Office, Italian Medicines Agency (AIFA), Rome, Italy
| | - Bengt Winblad
- Alzheimer Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Miia Kivipelto
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- Alzheimer Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
- Department of Neurology, University of Eastern Finland, Kuopio, Finland
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Bao Y, Zhang C, Yang W, Hu J, Sun X. Mechanism and kinetics study on the OH-initiated oxidation of organophosphorus pesticide trichlorfon in atmosphere. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 419:144-150. [PMID: 22289171 DOI: 10.1016/j.scitotenv.2012.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 11/13/2011] [Accepted: 01/04/2012] [Indexed: 05/31/2023]
Abstract
Trichlorfon [O,O-dimethyl-(2,2,2-trichloro-1-hydroxy-ethyl) phosphonate] (TCF) is a kind of widely used organophosphorus pesticides. In this paper, the mechanism and possible oxidation products for the OH-initiated reactions of TCF are studied at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. The study shows that H abstraction reaction from the CH(3) group and the CH group as well as OH addition reaction to the P atom are energetically favorable for the reactions of TCF and the main products are (CH(3)O)(2)POOH (P1), CCl(3)CHOHPOOH(OCH(3)) (P2), CH(3)OPO(2) (P3), CCl(3)COPO(OCH(3))(2) (P6) and HCHO. On the basis of the quantum chemical information, the kinetic calculation is performed and the rate constants are calculated over a temperature range of 200-800K using the transition state theory and canonical variational transition state theory with small-curvature tunneling effect. The Arrhenius formulas of rate constants with the temperature are fitted and the lifetimes of the reaction species in the troposphere are estimated according to the rate constants, which can provide helpful information for the model simulation study.
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Affiliation(s)
- Yuan Bao
- Environment Research Institute, Shandong University, Jinan 250100, PR China
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15
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Becker RE, Greig NH. Why so few drugs for Alzheimer's disease? Are methods failing drugs? Curr Alzheimer Res 2011; 7:642-51. [PMID: 20704560 DOI: 10.2174/156720510793499075] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 06/02/2010] [Indexed: 11/22/2022]
Abstract
Recent studies of Alzheimer's disease (AD) and other neuropsychiatric drug developments raise questions whether failures of some drugs occur due to flaws in methods. In three case studies of recent AD drug development failures with phenserine, metrifonate, and tarenflurbil we identified methodological lapses able to account for the failures. Errors in complex systems such as drug developments are both almost inescapable due to human mistakes and most frequently hidden at the time of occurrence and thereafter. We propose preemptive error management as a preventive strategy to exclude or control error intrusions into neuropsychiatric drug developments. We illustrate the functions we anticipate for a preemptive error management preventive strategy with a checklist and identify the limitations of this aspect of the proposal with three drug examples. This strategy applies core scientific practices to insure the quality of data within the current context of AD drug development practices.
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Affiliation(s)
- R E Becker
- Drug Design & Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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16
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Alzheimer's disease and related neurodegenerative disorders: implication and counteracting of melatonin. J Appl Biomed 2011. [DOI: 10.2478/v10136-011-0003-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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17
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Pharmacogenetic regulation of acetylcholinesterase activity in Drosophila reveals the regulatory mechanisms of AChE inhibitors in synaptic plasticity. Neurochem Res 2011; 36:879-93. [PMID: 21305389 DOI: 10.1007/s11064-011-0418-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2011] [Indexed: 12/13/2022]
Abstract
We conducted experiments in Drosophila to investigate the consequences of altered acetylcholinesterase (AChE) activity in the nervous system. In ace hypomorphic mutant larvae, the amount of ace mRNA and the activity of AChE both in vivo and in vitro were significantly reduced compared with those of controls. Reduced Ace in Drosophila larvae resulted in significant down-regulation of branch length and the number of boutons in Type 1 glutamatergic neuromuscular junctions (NMJs). These defects in ace hypomorphic mutant larvae were suppressed when Musca domestica AChE was transgenically expressed. Because AChE inhibitors are utilized for medications for Alzheimer's disease, we investigated whether pharmacological inhibition of AChE activity induced any synaptic defects. We found that controls exposed to a sublethal dose of DDVP phenocopied the synaptic structural defects of the ace hypomorphic mutant. These results suggest that down-regulation of AChE activity, regardless of whether it is due to genetic or pharmacological manipulations, results in altered synaptic architecture. Our study suggests that exposure to AChE inhibitors for 6-12 months may induce altered synaptic architectures in human brains with Alzheimer's diseases, similar to those reported here. These changes may underlie or contribute to the loss of efficacy of AChE inhibitors after prolonged treatment.
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Miltefosine, a promising novel agent for schistosomiasis mansoni. Int J Parasitol 2011; 41:235-42. [DOI: 10.1016/j.ijpara.2010.09.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/08/2010] [Accepted: 09/09/2010] [Indexed: 12/13/2022]
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19
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Olmos C, Sandoval R, Rozas C, Navarro S, Wyneken U, Zeise M, Morales B, Pancetti F. Effect of short-term exposure to dichlorvos on synaptic plasticity of rat hippocampal slices: Involvement of acylpeptide hydrolase and α7 nicotinic receptors. Toxicol Appl Pharmacol 2009; 238:37-46. [DOI: 10.1016/j.taap.2009.04.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 04/02/2009] [Accepted: 04/10/2009] [Indexed: 11/29/2022]
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20
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Treatment of urinary schistosomiasis: methodological issues and research needs identified through a Cochrane systematic review. Parasitology 2009; 136:1837-49. [PMID: 19493363 DOI: 10.1017/s0031182009005939] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Guidelines recommend praziquantel (PZQ) for the treatment and control of schistosomiasis, with no real alternative. Metrifonate was still widely used against Schistosoma haematobium in the 1990s, and then withdrawn. Experimental studies and clinical trials suggest that artemisinin compounds are active against S. haematobium. In a Cochrane systematic review assessing the efficacy and safety of drugs for treating urinary schistosomiasis, 24 randomized controlled trials (n=6315 individuals) met our inclusion criteria. These trials compared a variety of single agent and combination regimens with PZQ, metrifonate or artemisinin derivatives. The review confirmed that both the standard recommended doses of PZQ (single 40 mg/kg oral dose) and metrifonate (3x7.5-10 mg/kg oral doses administered fortnightly) are efficacious and safe in treating urinary schistosomiasis, but there is no study comparing these two regimens head-to-head. There is currently not enough evidence to evaluate artemisinin compounds. Most of the studies included in the Cochrane systematic review were insufficiently powered, lacked standardization in assessing and reporting outcomes, and had a number of methodological limitations. In this paper we discuss the implications of these findings with respect to public health and research methodology and propose priority research needs.
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Lanctôt KL, Rajaram RD, Herrmann N. Therapy for Alzheimer's Disease: How Effective are Current Treatments? Ther Adv Neurol Disord 2009; 2:163-80. [PMID: 21179526 PMCID: PMC3002627 DOI: 10.1177/1756285609102724] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Available symptomatic therapies for the treatment of Alzheimer's disease (AD) have been based on known neurotransmitter dysfunctions associated with the illness. The second-generation cholinesterase inhibitors and the N-methyl D-aspartate receptor antagonist memantine have been widely prescribed and studied. Meta-analyses of these therapies were reviewed, focusing on effectiveness and tolerability. Although many of the meta-analyses demonstrate statistically significant improvements, some question if these benefits are sufficient to justify their current widespread and protracted use. This has spurred the development of new disease-modifying therapies that aim to have a greater impact on this debilitating illness.
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Affiliation(s)
- Krista L Lanctôt
- Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
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22
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Abstract
BACKGROUND Urinary schistosomiasis causes long-term ill-health. This review examines the various treatment options and newer drugs. OBJECTIVES To evaluate antischistosomal drugs, used alone or in combination, for treating urinary schistosomiasis. SEARCH STRATEGY In August 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 3), MEDLINE, EMBASE, LILACS, mRCT, and reference lists of articles. We also contacted experts in schistosomiasis research. SELECTION CRITERIA Randomized and quasi-randomized controlled trials of praziquantel, metrifonate, artemisinin derivatives, or albendazole, alone or in combination, versus placebo, different doses, or other antischistosomal drugs for treating urinary schistosomiasis. DATA COLLECTION AND ANALYSIS One author extracted data, and assessed eligibility and methodological quality, which were cross-checked by a second person. Dichotomous outcomes were combined using risk ratio (RR), and continuous data were combined using weighted mean difference (WMD); both presented with 95% confidence intervals (CI). MAIN RESULTS Twenty-four trials (6315 participants) met the inclusion criteria. Compared with placebo, participants receiving metrifonate had fewer parasitological failures at follow up at one to three months (1 trial) and three to 12 months (3 trials). Egg reduction rate was over 90%, and no adverse events were reported (1 trial). One metrifonate dose was inferior to three doses given fortnightly (both used 10 mg/kg). Praziquantel (standard single 40 mg/kg oral dose) was more effective than placebo at reducing parasitological failure at one to three months' follow up and three to 12 months. Egg reduction rates were improved with praziquantel (over 95% versus 5.3% to 64% with placebo). Mild to moderate adverse events were recorded in two trials. A comparison of metrifonate (10 mg/kg x 3, once every 4 months for one year) with praziquantel (standard dose) showed little difference in parasitological failure. For praziquantel, there was no significant difference in effect between 20 mg/kg x 2, 30 mg/kg x 1, and 20 mg/kg x 1, and the standard dose for all outcomes. One small trial of artesunate showed no obvious benefit compared with placebo, and the artesunate-praziquantel combination was similar to praziquantel alone. AUTHORS' CONCLUSIONS Praziquantel and metrifonate are effective treatments for urinary schistosomiasis and have few adverse events. Metrifonate requires multiple administrations and is therefore operationally less convenient in community-based control programmes. Evidence on the artemisinin derivatives is currently inconclusive, and further research is warranted on combination therapies. We suggest metrifonate be reconsidered for the WHO Model List of Essential Medicines.
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Affiliation(s)
- Anthony Danso-Appiah
- International Health Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK, L3 5QA.
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Karademir Catalgol B, Ozden S, Alpertunga B. Effects of trichlorfon on malondialdehyde and antioxidant system in human erythrocytes. Toxicol In Vitro 2007; 21:1538-44. [PMID: 17697763 DOI: 10.1016/j.tiv.2007.06.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Revised: 05/10/2007] [Accepted: 06/05/2007] [Indexed: 11/26/2022]
Abstract
Organophosphorus insecticides may induce oxidative stress leading to generation of free radicals and alteration in antioxidant system. The aim of this study was to examine the potency of trichlorfon, an organophosphate insecticide, to induce oxidative stress response in human erythrocytes in vitro. For this purpose trichlorfon solutions in different concentrations and erythrocyte solutions were incubated at 37 degrees C for 60 min. At the end of the incubation time, malondialdehyde (MDA), an end product of lipid peroxidation, total glutathione, reduced glutathione (GSH) levels, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) enzymes were determined by spectrophotometric methods. Trichlorfon increased MDA formation depended on the concentration. On the other hand, decreases in the GSH-Px activity, GSH levels and increases in the total glutathione levels, SOD and CAT activities were seen in the studied concentrations. The present findings indicate that the in vitro toxicity of trichlorfon may be associated with oxidative stress.
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Affiliation(s)
- Betul Karademir Catalgol
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Istanbul University, Istanbul, Turkey
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Abstract
BACKGROUND Metrifonate is a long-acting irreversible cholinesterase inhibitor, originally used to treat schistosomiasis. Its potential to enhance central nervous system cholinergic neurotransmission led to clinical trials for the treatment of people with Alzheimer's disease (AD). Although low incidence of serious side effects occurred during short-term use as an antihelmintic, in studies of the treatment of AD extending over 6 months, 20 patients experienced respiratory paralysis and problems with neuromuscular transmission. These findings have led to a halt to trials of metrifonate for AD and Bayer, the pharmaceutical company, has withdrawn its FDA application. OBJECTIVES 1) To establish the efficacy of metrifonate for patients with Alzheimer's disease, in terms of cognition, global impression, functional activity, non cognitive symptoms, rate of institutionalization and mortality.2) Assess the safety and tolerability of metrifonate. SEARCH STRATEGY The Cochrane Dementia and Cognitive Improvement Group's Specialized Register was searched on 5 December 2005 using the term metrifonat*. This Register is regularly updated with records from all major health care databases (MEDLINE, EMBASE, CINAHL, PsycINFO) and many trials databases. One of the authors (LS), as member of the Metrifonate Study Group has had the opportunity to contact other metrifonate trialists to obtain data from potentially non published data of metrifonate clinical trials. SELECTION CRITERIA All unconfounded, randomized double-blind clinical controlled trials comparing metrifonate to placebo in people with AD. DATA COLLECTION AND ANALYSIS Data were extracted by the two reviewers, cross-checked, and pooled when appropriate and possible. MAIN RESULTS Most studies assessed changes in cognitive function, global function, activities of daily living, behavioural problems, severity of disease and adverse events. Occasionally the results were not reported in sufficient detail to allow extraction of data for the meta-analyses. The treatment regimens were varied: loading doses were used in some trials. The range of maintenance doses and studies were not pooled unless the treatment regimens were considered comparable. The lengths of treatment varied from 6 to 26 weeks and studies were not pooled unless the treatment duration was similar. The results are derived from the ITT populations. Metrifonate at various doses, fixed and loading doses, was associated with significant cognitive improvement compared to placebo, except for weekly doses where there was no difference from placebo: MMSE (metrifonate 60-80 mg/day with initial loading at 26 weeks; metrifonate 50 mg/day fixed dose with no initial loading at 26 weeks MD 1.85, 95% CI 1.06 to 2.64, p<0.00001); ADAS-Cog (metrifonate 60-80 mg/day with initial loading at 26 weeks MD -3.24, 95% CI -4.40 to -2.08, p<0.00001)In most trials, there was improvement in clinical global impression: CIBIC-Plus (metrifonate 30-55 mg/day, approximately 0.65 mg/kg body weight, with initial loading at 26 weeks MD -0.25, 95% CI -0.41 to -0.09 p=0.002; metrifonate 50 mg/day fixed dose with no initial loading at 26 weeks MD -0.20, 95% CI -0.39 to -0.01, p=0.04). There were generally-significant drug-placebo differences in activities of daily living but this often depended on sample size and the characteristics of the instrument used: DAD (metrifonate 30-55 mg/day, 0.65 mg/kg body weight, with initial loading at 26 weeks MD 2.72, 95% CI 0.66 to 4.77, p=0.01; metrifonate 50 mg/day fixed dose with no initial loading at 26 weeks MD 4.07, 95% CI 0.29 to 7.85, p=0.03)Also there were differences associated with metrifonate compared with placebo for different doses of metrifonate in scores on a behavioural symptom scale, caregiver burden scale, and severity of disease scale. Adverse events occurring more often with metrifonate included abdominal pain, bloating, bradycardia, diarrhoea, leg cramps, nausea and rhinitis and were described as mostly mild and transient, but occasionally moderately severe, and infrequently severe and serious. Analysis of the number of patients suffering at least one mild, moderate, severe or serious adverse event before the end of treatment showed that there was usually no difference between placebo and metrifonate. AUTHORS' CONCLUSIONS Metrifonate given once per day appears to be related to clinical response in cognition, global improvement, and activities of daily living in patients with mild to moderate Alzheimer's disease. Tolerability is good with adverse events as expected from a cholinesterase inhibitor, but with a low incidence of neuromuscular dysfunction and respiratory failure, too low to be detected in this review. It has been withdrawn from further development.
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Affiliation(s)
- J M López-Arrieta
- Consejería de Sanidad. Comunidad de Madrid, Hospital General Universitario Gregorio Marañón - Cantoblanco, Carretera de Colmenar km 14.500, Madrid, SPAIN, 28049.
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