Alzheimer’s Disease and other Tauopathies: Exploring Efficacy of Medicinal Plant-Derived Compounds in Alleviating Tau-Mediated Neurodegeneration

2021 ◽  
Vol 14 ◽  
Author(s):  
Siva Sundara Kumar Durairajan ◽  
Karthikeyan Selvarasu ◽  
Minu Rani Bera ◽  
Kaushik Rajaram ◽  
Ashok Iyaswamy ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Medicinal Plant ◽  
Tau Protein ◽  
Amyloid Β ◽  
Corticobasal Degeneration ◽  
Phase Iii ◽  
Disease Modifying Drugs ◽  
Stabilizing Agents ◽  
Phase Iii Clinical Trials

: Alzheimer’s disease (AD), a major form of dementia, has been reported to affect more than 50 million people worldwide. It is characterized by the presence of amyloid-β (Aβ) plaques and hyperphosphorylated Tau-associated neurofibrillary tangles in the brain. Apart from AD, microtubule (MT)-associated protein Tau is also involved in other neurodegenerative diseases called tauopathies, including Pick’s disease, frontotemporal lobar degeneration, progressive supranuclear palsy, and corticobasal degeneration. The recently unsuccessful phase III clinical trials related to Aβ-targeted therapeutic drugs indicated that alternative targets, such as Tau, should be studied to discover more effective and safer drugs. Recent drug discovery approaches to reduce AD-related Tau pathologies are primarily based on blocking Tau aggregation, inhibiting Tau phosphorylation, compensating impaired Tau function with MT-stabilizing agents, and targeting the degradation pathways in neuronal cells to degrade Tau protein aggregates. Owing to several limitations of the currently-available Tau-directed drugs, further studies are required to generate further effective and safer Tau-based disease-modifying drugs. Here, we review the studies that focused on medicinal plant-derived compounds capable of modulating the Tau protein, which is significantly elevated and hyperphosphorylated in AD and other tauopathies. We mainly considered the studies that focused on Tau protein as a therapeutic target. We reviewed several pertinent papers retrieved from PubMed and ScienceDirect using relevant keywords, with a primary focus on the Tau-targeting compounds from medicinal plants. These compounds include indolines, phenolics, flavonoids, coumarins, alkaloids, and iridoids, which have been scientifically proven to be Tau-targeting candidates for the treatment of AD.

scholarly journals New Approacher in the Development of Alzheimer’s Disease Modifying Drugs

2021 ◽  
pp. 88
Author(s):  
◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Tau Protein ◽  
Phase Iii ◽  
Disease Modifying Drugs ◽  
Phase Iii Clinical Trials ◽  
Research Level ◽  
Disease Modifying ◽  
Pathological Stages

Introduction: Alzheimer’s disease is a more common neurodegenerative disease, affecting 25 million people worldwide, or accounting for about 60 to 70% of all dementia cases. There is currently no exact mechanism to explain the pathophysiology of Alzheimer’s disease, however, cascading metabolic amyloid and post-translational review of tau protein are used as major hypotheses. Objective: To demonstrate in the literature new approaches in the development of Alzheimer’s disease modifiers. Methodology: For the accomplishment of this study made in the bibliographical survey of scientific literature and respect to the approached subject, in the databases PUBMED, ScienceDirect, Scielo and Scopus. Results: Alzheimer’s disease-modifying drugs are not yet available, but many patients may, however, develop phase III clinical trials and are intended to modify as pathological stages leading to the disease. As disease-modifying therapies under study, these changes also affect Aβ and tau protein and also cause inflammation and oxidative damage. The results obtained in the clinical trials performed were positive and promising and are still under study. The results show that there is still a long way to go in the development of Alzheimer’s disease modifying drugs. Conclusion: The results demonstrated that there is still a long way to go in the development of Alzheimer’s disease modifying drugs, but nevertheless levels at the research level should be continued in order to improve the pathophysiology of the disease and find an effective treatment for this disease the same.

Is it All Said for NSAIDs in Alzheimer’s Disease? Role of Mitochondrial Calcium Uptake

2018 ◽  
Vol 15 (6) ◽  
pp. 504-510 ◽  
Author(s):  
Sara Sanz-Blasco ◽  
Maria Calvo-Rodríguez ◽  
Erica Caballero ◽  
Monica Garcia-Durillo ◽  
Lucia Nunez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Death ◽  
Amyloid Β ◽  
Epidemiological Data ◽  
Amyloid Β Peptide ◽  
Aβ Oligomers ◽  
Mitochondrial Potential ◽  
Disease Modifying Drugs ◽  
Definitive Evidence

Objectives: Epidemiological data suggest that non-steroidal anti-inflammatory drugs (NSAIDs) may protect against Alzheimer's disease (AD). Unfortunately, recent trials have failed in providing compelling evidence of neuroprotection. Discussion as to why NSAIDs effectivity is uncertain is ongoing. Possible explanations include the view that NSAIDs and other possible disease-modifying drugs should be provided before the patients develop symptoms of AD or cognitive decline. In addition, NSAID targets for neuroprotection are unclear. Both COX-dependent and independent mechanisms have been proposed, including γ-secretase that cleaves the amyloid precursor protein (APP) and yields amyloid β peptide (Aβ). Methods: We have proposed a neuroprotection mechanism for NSAIDs based on inhibition of mitochondrial Ca2+ overload. Aβ oligomers promote Ca2+ influx and mitochondrial Ca2+ overload leading to neuron cell death. Several non-specific NSAIDs including ibuprofen, sulindac, indomethacin and Rflurbiprofen depolarize mitochondria in the low µM range and prevent mitochondrial Ca2+ overload induced by Aβ oligomers and/or N-methyl-D-aspartate (NMDA). However, at larger concentrations, NSAIDs may collapse mitochondrial potential (ΔΨ) leading to cell death. Results: Accordingly, this mechanism may explain neuroprotection at low concentrations and damage at larger doses, thus providing clues on the failure of promising trials. Perhaps lower NSAID concentrations and/or alternative compounds with larger dynamic ranges should be considered for future trials to provide definitive evidence of neuroprotection against AD.

A Numerical Study of Sensitivity Coefficients for a Model of Amyloid Precursor Protein and Tubulin-Associated Unit Protein Transport and Agglomeration in Neurons at the Onset of Alzheimer's Disease

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
I. A. Kuznetsov ◽  
A. V. Kuznetsov
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Precursor Protein ◽  
Tau Protein ◽  
Protein Transport ◽  
Numerical Study ◽  
Amyloid Β ◽  
Precursor Protein ◽  
Model Parameters ◽  
In The Beginning

Modeling of intracellular processes occurring during the development of Alzheimer's disease (AD) can be instrumental in understanding the disease and can potentially contribute to finding treatments for the disease. The model of intracellular processes in AD, which we previously developed, contains a large number of parameters. To distinguish between more important and less important parameters, we performed a local sensitivity analysis of this model around the values of parameters that give the best fit with published experimental results. We show that the influence of model parameters on the total concentrations of amyloid precursor protein (APP) and tubulin-associated unit (tau) protein in the axon is reciprocal to the influence of the same parameters on the average velocities of the same proteins during their transport in the axon. The results of our analysis also suggest that in the beginning of AD the aggregation of amyloid-β and misfolded tau protein have little effect on transport of APP and tau in the axon, which suggests that early damage in AD may be reversible.

scholarly journals Carboxy-Terminus Tau Protein Hyperphosphorylation is Associated with Extracellular Deposits of Amyloid-β Fibrillary in a Triple-Transgenic Model of Alzheimer’s Disease

2017 ◽  
Vol 05 (03) ◽  
Author(s):  
Miguel Angel Ontiveros Torres ◽  
Leonel Castellanos Aguilar ◽  
Jonathan Lennel Gutierrez Murcia ◽  
Nayeli Martinez Zuniga ◽  
Paola Flores Rodriguez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Amyloid Β ◽  
Carboxy Terminus ◽  
Transgenic Model ◽  
Model Of Alzheimer’S Disease

Novel approaches to incorporating pharmacoeconomic studies into phase III clinical trials for Alzheimer's disease

2010 ◽  
Vol 14 (8) ◽  
pp. 640-647 ◽  
Author(s):  
H. Fillit ◽  
J. Cummings ◽  
P. Neumann ◽  
T. Mclaughlin ◽  
P. Salavtore ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Phase Iii ◽  
Phase Iii Clinical Trials ◽  
Novel Approaches

scholarly journals New pharmacological strategies for the treatment of alzheimer’s disease

2021 ◽  
Author(s):  
Letícia Freitas de Castro Silva ◽  
Elisa Pinheiro Weber ◽  
Gleice Silva Toledo ◽  
Josiane Fonseca Almeida
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Tau Protein ◽  
Amyloid Β ◽  
The Elderly ◽  
New Drugs ◽  
Pathophysiological Mechanisms ◽  
Apoe Protein ◽  
New Biomarkers

Introduction: Alzheimer’s disease (AD) is seen as the most important dementia, prevalent in the elderly over 60 years old. There is still no cure, and the pharmacological strategies are to delay the symptoms and development of the pathology. The pathophysiological mechanisms are: hyperphosphorylation of the tau protein and aggregation of amyloid-β. Update studies of the tested therapies target the main pathological mechanisms: accumulation of β amyloid (inhibitors and modulators of β-secretase and γ-secretase and active and passive anti-Aβ immunotherapies), tau protein (inhibition of abnormal hyperphosphorylation with GSK-3 inhibitors, passive and active immunotherapies and the use of intrathecal antisense oligonucleotides (ASOs) and correction of the ApoE protein (increase lipidation, correct structure, clearance of non-lipid ApoE and reduction of ApoE expression). Objectives and methodology: To develop a bibliographic review in order to address new drugs in the treatment of Alzheimer’s. Qualitative and descriptive study carried out by literary review with research on PubMed. Results: Several drugs have been tested in clinical trials, however, due to lack of effectiveness, none have been approved. Therefore, it’s important to understand the limitations of the tests developed as flaws in the methodology, insufficient understanding of the mechanisms involved and inclusion of patients in different stages of AD, so that future investigations can overcome these gaps. Conclusion: It’s important to investigate new pathophysiological mechanisms, as well as the factors that trigger AD. Diagnosis is essential, with further studies to identify new biomarkers of the disease that will also have an impact on the conduct of clinical trials.

Alzheimer's Disease: Progress in the Development of Anti-amyloid Disease-Modifying Therapies

CNS Spectrums ◽  
2007 ◽  
Vol 12 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Daniel D. Christensen
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Amyloid Β ◽  
Phase Iii ◽  
Peroxisome Proliferator ◽  
Serious Adverse Events ◽  
Amyloid Disease ◽  
Aβ Aggregation ◽  
Disease Modifying

ABSTRACTThe amyloid hypothesis—the leading mechanistic theory of Alzheimer's disease—states that an imbalance in production or clearance of amyloid β (Aβ) results in accumulation of Aβ and triggers a cascade of events leading to neurodegeneration and dementia. The number of persons with Alzheimer's disease is expected to triple by mid-century. If steps are not taken to delay the onset or slow the progression of Alzheimer's disease, the economic and personal tolls will be immense. Different classes of potentially disease-modifying treatments that interrupt early pathological events (ie, decreasing production or aggregation of Aβ or increasing its clearance) and potentially prevent downstream events are in phase II or III clinical studies. These include immunotherapies; secretase inhibitors; selective Aβ42-lowering agents; statins; anti-Aβ aggregation agents; peroxisome proliferator-activated receptor-gamma agonists; and others. Safety and serious adverse events have been a concern with immunotherapy and γ-secretase inhibitors, though both continue in clinical trials. Anti-amyloid disease-modifying drugs that seem promising and have reached phase III clinical trials include those that selectively target Aβ42 production (eg, tarenflurbil), enhance the activity of α-secretase (eg, statins), and block Aβ aggregation (eg, transiposate).

scholarly journals Therapeutic Mechanism and Key Alkaloids of Uncaria rhynchophylla in Alzheimer’s Disease From the Perspective of Pathophysiological Processes

2021 ◽  
Vol 12 ◽  
Author(s):  
Peng Zeng ◽  
Hong-Fei Su ◽  
Chao-Yuan Ye ◽  
Shuo-Wen Qiu ◽  
Qing Tian
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
High Performance ◽  
Amyloid Β ◽  
Pathological Process ◽  
Network Pharmacology ◽  
Disease Modifying Drugs ◽  
Uncaria Rhynchophylla ◽  
Therapeutic Mechanism ◽  
Aβ Production

Presently, there is a lack of effective disease-modifying drugs for the treatment of Alzheimer’s disease (AD). Uncaria rhynchophylla (UR) and its predominant active phytochemicals alkaloids have been studied to treat AD. This study used a novel network pharmacology strategy to identify UR alkaloids against AD from the perspective of AD pathophysiological processes and identified the key alkaloids for specific pathological process. The analysis identified 10 alkaloids from UR based on high-performance liquid chromatography (HPLC) that corresponded to 127 targets correlated with amyloid-β (Aβ) pathology, tau pathology and Alzheimer disease pathway. Based on the number of targets correlated with AD pathophysiological processes, angustoline, angustidine, corynoxine and isocorynoxeine are highly likely to become key phytochemicals in AD treatment. Among the 127 targets, JUN, STAT3, MAPK3, CCND1, MMP2, MAPK8, GSK3B, JAK3, LCK, CCR5, CDK5 and GRIN2B were identified as core targets. Based on the pathological process of AD, angustoline, angustidine and isocorynoxeine were identified as the key UR alkaloids regulating Aβ production and corynoxine, isocorynoxeine, dihydrocorynatheine, isorhynchophylline and hirsutine were identified as key alkaloids that regulate tau phosphorylation. The findings of this study contribute to a more comprehensive understanding of the key alkaloids and mechanisms of UR in the treatment of AD, as well as provide candidate compounds for drug research and development for specific AD pathological processes.

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