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Viruses Mar 2021Since the SARS-CoV-2 pandemic started in late 2019, the search for protective vaccines and for drug treatments has become mandatory to fight the global health emergency....
Since the SARS-CoV-2 pandemic started in late 2019, the search for protective vaccines and for drug treatments has become mandatory to fight the global health emergency. Travel restrictions, social distancing, and face masks are suitable counter measures, but may not bring the pandemic under control because people will inadvertently or at a certain degree of restriction severity or duration become incompliant with the regulations. Even if vaccines are approved, the need for antiviral agents against SARS-CoV-2 will persist. However, unequivocal evidence for efficacy against SARS-CoV-2 has not been demonstrated for any of the repurposed antiviral drugs so far. Amantadine was approved as an antiviral drug against influenza A, and antiviral activity against SARS-CoV-2 has been reasoned by analogy but without data. We tested the efficacy of amantadine in vitro in Vero E6 cells infected with SARS-CoV-2. Indeed, amantadine inhibited SARS-CoV-2 replication in two separate experiments with IC concentrations between 83 and 119 µM. Although these IC concentrations are above therapeutic amantadine levels after systemic administration, topical administration by inhalation or intranasal instillation may result in sufficient amantadine concentration in the airway epithelium without high systemic exposure. However, further studies in other models are needed to prove this hypothesis.
Topics: Amantadine; Animals; Antiviral Agents; COVID-19; Chlorocebus aethiops; Humans; SARS-CoV-2; Vero Cells; Virus Replication; COVID-19 Drug Treatment
PubMed: 33804989
DOI: 10.3390/v13040539 -
International Journal of Molecular... Jun 2023Tau protein aggregations are important contributors to the etiology of Alzheimer's disease (AD). Hydromethylthionine (HMT) is a potent inhibitor of tau aggregation in...
Tau protein aggregations are important contributors to the etiology of Alzheimer's disease (AD). Hydromethylthionine (HMT) is a potent inhibitor of tau aggregation in vitro and in vivo and is being developed as a possible anti-dementia medication. HMT was also shown to affect the cholinergic system and to interact with mitochondria. Here, we used tau-transgenic (L1 and L66) and wild-type NMRI mice that were treated with HMT, rivastigmine and memantine and with combinations thereof, for 2-4 weeks. We measured HMT concentrations in both brain homogenates and isolated mitochondria and concentrations of glucose, lactate and pyruvate in brain by microdialysis. In isolated brain mitochondria, we recorded oxygen consumption of mitochondrial complexes by respirometry. While rivastigmine and memantine lowered mitochondrial respiration, HMT did not affect respiration in wild-type animals and increased respiration in tau-transgenic L1 mice. Glucose and lactate levels were not affected by HMT administration. The presence of HMT in isolated mitochondria was established. In summary, traditional anti-dementia drugs impair mitochondrial function while HMT has no adverse effects on mitochondrial respiration in tau-transgenic mice. These results support the further development of HMT as an anti-dementia drug.
Topics: Mice; Animals; Rivastigmine; Memantine; tau Proteins; Mice, Transgenic; Cholinesterase Inhibitors; Alzheimer Disease; Mitochondria
PubMed: 37445987
DOI: 10.3390/ijms241310810 -
Current Neuropharmacology 2016Dementia, which can be induced by diverse factors, is a clinical syndrome characterized by the decline of cognitive function. Behavioral and psychological symptoms of... (Review)
Review
Dementia, which can be induced by diverse factors, is a clinical syndrome characterized by the decline of cognitive function. Behavioral and psychological symptoms of dementia (BPSD) include depression, agitation, and aggression. Dementia causes a heavy burden on patients and their caregivers. Patients with BPSD should be assessed comprehensively by practitioners and offered appropriate non-pharmacologic and pharmacologic therapy. Nonpharmacologic therapy has been recommended as the basal treatment for BPSD; however, pharmacologic therapy is required under many situations. Medications, including antipsychotic agents, antidepressants, sedative and hypnotic agents, mood stabilizers, cholinesterase inhibitors, and amantadine, are extensively used in clinical practice. We have reviewed the progression of pharmacologic therapy for BPSD.
Topics: Amantadine; Antidepressive Agents; Antipsychotic Agents; Behavioral Symptoms; Cholinesterase Inhibitors; Dementia; Female; Humans; Hypnotics and Sedatives; Male; Treatment Outcome
PubMed: 26644152
DOI: 10.2174/1570159x14666151208114232 -
Neurobiology of Disease Jun 2023Epilepsy is considered to result from an imbalance between excitation and inhibition of the central nervous system. Pathogenic mutations in the methyl-CpG binding domain...
Epilepsy is considered to result from an imbalance between excitation and inhibition of the central nervous system. Pathogenic mutations in the methyl-CpG binding domain protein 5 gene (MBD5) are known to cause epilepsy. However, the function and mechanism of MBD5 in epilepsy remain elusive. Here, we found that MBD5 was mainly localized in the pyramidal cells and granular cells of mouse hippocampus, and its expression was increased in the brain tissues of mouse models of epilepsy. Exogenous overexpression of MBD5 inhibited the transcription of the signal transducer and activator of transcription 1 gene (Stat1), resulting in increased expression of N-methyl-d-aspartate receptor (NMDAR) subunit 1 (GluN1), 2A (GluN2A) and 2B (GluN2B), leading to aggravation of the epileptic behaviour phenotype in mice. The epileptic behavioural phenotype was alleviated by overexpression of STAT1 which reduced the expression of NMDARs, and by the NMDAR antagonist memantine. These results indicate that MBD5 accumulation affects seizures through STAT1-mediated inhibition of NMDAR expression in mice. Collectively, our findings suggest that the MBD5-STAT1-NMDAR pathway may be a new pathway that regulates the epileptic behavioural phenotype and may represent a new treatment target.
Topics: Animals; Mice; Epilepsy; Memantine; Receptors, N-Methyl-D-Aspartate; Seizures; Signal Transduction; STAT1 Transcription Factor
PubMed: 36997128
DOI: 10.1016/j.nbd.2023.106103 -
Parkinsonism & Related Disorders Mar 2022Immediate-release (IR) amantadine has been used for treatment of levodopa induced dyskinesia (LID). The immediate-release/extended-release (IR/ER) amantadine formulation... (Randomized Controlled Trial)
Randomized Controlled Trial
Immediate-release/extended-release amantadine (OS320) to treat Parkinson's disease with levodopa-induced dyskinesia: Analysis of the randomized, controlled ALLAY-LID studies.
BACKGROUND
Immediate-release (IR) amantadine has been used for treatment of levodopa induced dyskinesia (LID). The immediate-release/extended-release (IR/ER) amantadine formulation OS320 (OSMOLEX ER®) contains an IR outer layer and ER core for once-daily dosing.
OBJECTIVE
Report individual and pooled results for the similarly designed double-blind, placebo-controlled ALLAY-LID I and II trials, assessing IR/ER-amantadine for LID.
METHODS
PD patients with LID were randomized to IR/ER-amantadine 193 mg, 258 mg, or placebo. Primary endpoint was Unified Dyskinesia Rating Scale (UDysRS) score change from baseline to Day 98. Secondary outcome was ON time without troublesome dyskinesia based on diaries. Exploratory outcomes were other diary states (including OFF), MDS-UPDRS Parts II + III and Fatigue Severity Scale.
RESULTS
Overall, 222 individuals enrolled (N = 87 ALLAY-LID I, N = 135 ALLAY-LID II); both trials terminated early for sponsor's decision. While ALLAY-LID I did not meet its primary endpoint, a significant reduction in UDysRS scores versus placebo was observed in ALLAY-LID II for both 193 mg and 258 mg doses. In the pooled analysis, placebo-adjusted UDysRS score differences were -5.5 [-9.8, -1.2], p = 0.012 and -5.2 [-9.5, -0.9], p = 0.017, respectively. IR/ER-amantadine 258 mg significantly increased time spent ON without troublesome dyskinesia in ALLAY-LID II and pooled analysis. Reductions in ON time with dyskinesia supported the primary outcome. There was no effect on OFF time or other outcomes. Overall, 13.3% (193 mg), 18.7% (258 mg) and 11.1% (placebo) discontinued for adverse events, most commonly hallucinations (4.0%, 10.7%, and 1.4%, respectively).
CONCLUSIONS
IR/ER-amantadine significantly reduced LID in ALLAY-LID II but not in ALLAY-LID I; post-hoc pooled data also indicated a positive treatment effect on LID.
Topics: Amantadine; Antiparkinson Agents; Double-Blind Method; Dyskinesia, Drug-Induced; Humans; Levodopa; Parkinson Disease; Treatment Outcome
PubMed: 35227940
DOI: 10.1016/j.parkreldis.2022.01.022 -
The Journal of Clinical Psychiatry Dec 2019Patients with obsessive-compulsive disorder (OCD) who do not respond adequately to serotonin reuptake inhibitor (SRI) therapy and cognitive behavioral therapy commonly... (Meta-Analysis)
Meta-Analysis Review
Patients with obsessive-compulsive disorder (OCD) who do not respond adequately to serotonin reuptake inhibitor (SRI) therapy and cognitive behavioral therapy commonly receive SRI augmentation in the form of an atypical antipsychotic drug. Memantine is another augmentation strategy that has been trialed. A recent systematic review and meta-analysis found very large improvements associated with memantine augmentation in OCD. Specifically, in 4 randomized controlled trials (RCTs), the response rate was 81% in 67 memantine-treated patients vs only 19% in 68 placebo-treated patients. The weighted mean difference between memantine and placebo groups was nearly 8 points on the Yale-Brown Obsessive Compulsive Scale. Such striking differences for intervention vs placebo in a difficult-to-treat disorder demand scrutiny. An examination of the RCTs on which the meta-analysis was based showed that all 4 RCTs emerged from the same geographical area, limiting the generalizability of the findings. Of greater concern, all 4 RCTs presented what were effectively completer analyses of data, compromising the scientific validity of the findings. There were several other concerns about the individual studies and about the meta-analysis, itself. Therefore, a reasonable conclusion is that, when the internal and external validity of studies in a meta-analysis are compromised, the findings and conclusions of the meta-analysis cannot be considered sound. It is concluded that, despite the very large benefits reportedly associated with memantine augmentation, the routine use of memantine as an augmentation agent for OCD cannot as yet be recommended.
Topics: Cognitive Behavioral Therapy; Combined Modality Therapy; Drug Therapy, Combination; Humans; Memantine; Obsessive-Compulsive Disorder; Randomized Controlled Trials as Topic; Selective Serotonin Reuptake Inhibitors
PubMed: 31846244
DOI: 10.4088/JCP.19f13163 -
European Review For Medical and... Oct 2022Amantadine is known to have a neuroprotective effect in many neurological diseases. This study aims at investigating the neuroprotective effect of amantadine in rats...
OBJECTIVE
Amantadine is known to have a neuroprotective effect in many neurological diseases. This study aims at investigating the neuroprotective effect of amantadine in rats exposed to carbon monoxide (CO) poisoning.
MATERIALS AND METHODS
Rats were maintained under standard experimental laboratory conditions and randomized into 4 different groups of 7 each namely control, amantadine only, CO exposure, and amantadine + CO exposure. For immunohistochemical analysis, tissues taken from the prefrontal and hippocampal regions were taken into formalin and kept for at least one day. Afterward, the tissue was followed and blocked for paraffin blocking. N-Methyl D-Aspartate (NMDA) levels in homogenates were studied by the Enzyme-Linked Immunosorbent Assay (ELISA) method. Superoxide dismutase (SOD) and catalase (CAT) activities in the supernatants were studied with commercial kits. Nitric oxide (NO) and Asymmetric Dimethyl Arginine (ADMA) levels were studied by the ELISA method. Enzyme activity values were calculated by dividing the protein values in the supernatants and normalizing them.
RESULTS
CAT, SOD, NMDA, ADMA, and NO levels were statistically significantly different between the groups (p < 0.05). According to post-hoc pairwise comparison test results, the values of the control and amantadine groups for CAT, SOD, NMDA, ADMA, and NO parameters were significantly higher than that of CO group. Similarly, values in the control and amantadine groups were considerably higher than values for the amantadine + CO group. NMDA values were significantly lower in group amantadine + CO than in CO group (p: 0.049).
CONCLUSIONS
Apoptosis and endothelial damage after CO poisoning is a complex process, and amantadine administration has a limited contribution in preventing this process.
Topics: Animals; Rats; Amantadine; Antioxidants; Arginine; Carbon Monoxide; Carbon Monoxide Poisoning; Catalase; D-Aspartic Acid; Formaldehyde; N-Methylaspartate; Neuroprotective Agents; Nitric Oxide; Paraffin; Receptors, N-Methyl-D-Aspartate; Superoxide Dismutase
PubMed: 36263571
DOI: 10.26355/eurrev_202210_29872 -
Discovery Medicine May 2016Melatonin levels have been shown to decline with aging. Melatonin and its analogs in addition to their effect on sleep promotion, has been shown to have multiple... (Review)
Review
Melatonin levels have been shown to decline with aging. Melatonin and its analogs in addition to their effect on sleep promotion, has been shown to have multiple pleiotropic effects. It can also help with neuroprotection through different mechanisms. Evidence in animal and human studies suggests that low levels of melatonin have been linked to delirium, mild cognitive impairment, dementia, and with certain behavioral problems. Recent clinical trials have showed that both melatonin and its analogs may be useful in the prevention, treatment of delirium, and the management of dementia. These medications seem to have the advantage of less side effects and better safety profile when compared to antipsychotics and sedatives like benzodiazepines. These medications are available over the counter in North America, Europe, and Asia, and some of these medications are approved by FDA. This manuscript will discuss the promising role of these melatonergic medications alone or in combination with other medications for the management of Geriatric Psychiatric diseases like delirium and dementia.
Topics: Aged; Animals; Antipsychotic Agents; Benzodiazepines; Chronobiology Phenomena; Clinical Trials as Topic; Delirium; Dementia; Drug Therapy, Combination; Galantamine; Humans; Indenes; Melatonin; Memantine; Neuroprotection; Practice Guidelines as Topic
PubMed: 27355332
DOI: No ID Found -
Amantadine and Rimantadine Inhibit Hepatitis A Virus Replication through the Induction of Autophagy.Journal of Virology Sep 2022Hepatitis A virus (HAV) infection is a major cause of acute viral hepatitis worldwide. Furthermore, HAV causes acute liver failure or acute-on-chronic liver failure....
Hepatitis A virus (HAV) infection is a major cause of acute viral hepatitis worldwide. Furthermore, HAV causes acute liver failure or acute-on-chronic liver failure. However, no potent anti-HAV drugs are currently available in the clinical situations. There have been some reports that amantadine, a broad-spectrum antiviral, suppresses HAV replication . Therefore, we examined the effects of amantadine and rimantadine, derivates of adamantane, on HAV replication, and investigated the mechanisms of these drugs. In the present study, we evaluated the effects of amantadine and rimantadine on HAV HM175 genotype IB subgenomic replicon replication and HAV HA11-1299 genotype IIIA replication in cell culture infection systems. Amantadine and rimantadine significantly inhibited HAV replication at the post-entry stage in Huh7 cells. HAV infection inhibited autophagy by suppressing the autophagy marker light chain 3 and reducing number of lysosomes. Proteomic analysis on HAV-infected Huh7 cells treated by amantadine and rimantadine revealed the changes of the expression levels in 42 of 373 immune response-related proteins. Amantadine and rimantadine inhibited HAV replication, partially through the enhancement of autophagy. Taken together, our results suggest a novel mechanism by which HAV replicates along with the inhibition of autophagy and that amantadine and rimantadine inhibit HAV replication by enhancing autophagy. Amantadine, a nonspecific antiviral medication, also effectively inhibits HAV replication. Autophagy is an important cellular mechanism in several virus-host cell interactions. The results of this study provide evidence indicating that autophagy is involved in HAV replication and plays a role in the HAV life cycle. In addition, amantadine and its derivative rimantadine suppress HAV replication partly by enhancing autophagy at the post-entry phase of HAV infection in human hepatocytes. Amantadine may be useful for the control of acute HAV infection by inhibiting cellular autophagy pathways during HAV infection processes.
Topics: Amantadine; Antiviral Agents; Autophagy; Cell Line; Hepatitis A; Hepatitis A Antibodies; Hepatitis A virus; Humans; Proteomics; Rimantadine; Virus Replication
PubMed: 36040176
DOI: 10.1128/jvi.00646-22 -
Molecular Neurodegeneration Jul 2023Stroke and late-onset Alzheimer's disease (AD) are risk factors for each other; the comorbidity of these brain disorders in aging individuals represents a significant... (Review)
Review
Stroke and late-onset Alzheimer's disease (AD) are risk factors for each other; the comorbidity of these brain disorders in aging individuals represents a significant challenge in basic research and clinical practice. The similarities and differences between stroke and AD in terms of pathogenesis and pathophysiology, however, have rarely been comparably reviewed. Here, we discuss the research background and recent progresses that are important and informative for the comorbidity of stroke and late-onset AD and related dementia (ADRD). Glutamatergic NMDA receptor (NMDAR) activity and NMDAR-mediated Ca influx are essential for neuronal function and cell survival. An ischemic insult, however, can cause rapid increases in glutamate concentration and excessive activation of NMDARs, leading to swift Ca overload in neuronal cells and acute excitotoxicity within hours and days. On the other hand, mild upregulation of NMDAR activity, commonly seen in AD animal models and patients, is not immediately cytotoxic. Sustained NMDAR hyperactivity and Ca dysregulation lasting from months to years, nevertheless, can be pathogenic for slowly evolving events, i.e. degenerative excitotoxicity, in the development of AD/ADRD. Specifically, Ca influx mediated by extrasynaptic NMDARs (eNMDARs) and a downstream pathway mediated by transient receptor potential cation channel subfamily M member (TRPM) are primarily responsible for excitotoxicity. On the other hand, the NMDAR subunit GluN3A plays a "gatekeeper" role in NMDAR activity and a neuroprotective role against both acute and chronic excitotoxicity. Thus, ischemic stroke and AD share an NMDAR- and Ca-mediated pathogenic mechanism that provides a common receptor target for preventive and possibly disease-modifying therapies. Memantine (MEM) preferentially blocks eNMDARs and was approved by the Federal Drug Administration (FDA) for symptomatic treatment of moderate-to-severe AD with variable efficacy. According to the pathogenic role of eNMDARs, it is conceivable that MEM and other eNMDAR antagonists should be administered much earlier, preferably during the presymptomatic phases of AD/ADRD. This anti-AD treatment could simultaneously serve as a preconditioning strategy against stroke that attacks ≥ 50% of AD patients. Future research on the regulation of NMDARs, enduring control of eNMDARs, Ca homeostasis, and downstream events will provide a promising opportunity to understand and treat the comorbidity of AD/ADRD and stroke.
Topics: Animals; Receptors, N-Methyl-D-Aspartate; Alzheimer Disease; Ischemic Stroke; Memantine; Stroke
PubMed: 37400870
DOI: 10.1186/s13024-023-00636-1