Potent Acetylcholinesterase Inhibitors: Potential Drugs for Alzheimer’s Disease

2020 ◽  
Vol 20 (8) ◽  
pp. 703-715 ◽  
Author(s):  
Hulya Akıncıoğlu ◽  
İlhami Gülçin

: Alzheimer’s disease (AD) is one of the cognitive or memory-related impairments occurring with advancing age. Since its exact mechanism is not known, the full therapy has still not been found. Acetylcholinesterase (AChE) has been reported to be a viable therapeutic target for the treatment of AD and other dementias. To this end, acetylcholinesterase inhibitors (AChEIs) are commonly used. AChE is a member of the hydrolase enzyme family. A hydrolase is an enzyme that catalyzes the hydrolysis of a chemical bond. AChE is useful for the development of novel and mechanism-based inhibitors. It has a role in the breakdown of acetylcholine (ACh) neurotransmitters, such as acetylcholinemediated neurotransmission. AChEIs are the most effective approaches to treat AD. AChE hydrolyzes ACh to acetate and choline, as an important neurotransmitter substance. Recently, Gülçin and his group explored new AChEIs. The most suggested mechanism for AD is the deficiency of ACh, which is an important neurotransmitter. In this regard, AChEIs are commonly used for the symptomatic treatment of AD. They act in different ways, such as by inhibiting AChE, protecting cells from free radical toxicity and β-amyloid-induced injury or inhibiting the release of cytokines from microglia and monocytes. This review focuses on the role of AChEIs in AD using commonly available drugs. Also, the aim of this review is to research and discuss the role of AChEIs in AD using commonly available drugs. Therefore, in our review, related topics like AD and AChEIs are highlighted. Also, the latest work related to AChEIs is compiled. In recent research studies, novel natural and synthetic AChEIs, used for AD, are quite noteworthy. These studies can be very promising in detecting potent drugs against AD.

2021 ◽  
Vol 15 ◽  
Author(s):  
Guimei Zhang ◽  
Zicheng Wang ◽  
Huiling Hu ◽  
Meng Zhao ◽  
Li Sun

Alzheimer’s disease (AD) is one of the most common types of age-related dementia worldwide. In addition to extracellular amyloid plaques and intracellular neurofibrillary tangles, dysregulated microglia also play deleterious roles in the AD pathogenesis. Numerous studies have demonstrated that unbridled microglial activity induces a chronic neuroinflammatory environment, promotes β-amyloid accumulation and tau pathology, and impairs microglia-associated mitophagy. Thus, targeting microglia may pave the way for new therapeutic interventions. This review provides a thorough overview of the pathophysiological role of the microglia in AD and illustrates the potential avenues for microglia-targeted therapies, including microglial modification, immunoreceptors, and anti-inflammatory drugs.


2020 ◽  
Vol 8 (4) ◽  
pp. 475-490
Author(s):  
A.P. Denysenko ◽  
O.O. Haikova ◽  
R.A. Moskalenko

Alzheimer's disease is the most common form of dementia affecting up to 70% of all patients with dementia. Currently, the relevance of this neurodegenerative disease has increased due to its prevalence and lack of etiological and effective treatment. The consequence of this is an increase in the number of studies and scientific works aimed at studying this disease. The aim of the study was to analyze and systematize data on the prevalence, socioeconomic significance, theories of origin, as well as the role of pathogenic proteins in the development of Alzheimer's disease. The authors searched for information in electronic databases such as PubMed and Google Scholar, with scientific papers and articles from the last 25 years on such key terms as Alzheimer's disease, β-amyloid, tau-peptide, metals, inflammation, S100 proteins. There are more than 56 million people with Alzheimer's disease in the world and the risk increases with age. Among the causes of death, Alzheimer's disease ranks sixth, and the costs of care about person with this diagnosis are three times higher than for other diseases in the same age group. That is why this issue has significant socio-economic significance. Many hypotheses have emerged in recent decades. For a long time, the theory of β-amyloid aggregation and the theory of tau protein were considered main, but later the priorities began to change. It has been found that the presence of pathogenic microorganisms can pose a risk for Alzheimer's disease. Also, some studies indicate the role of acetylcholine in the development of the disease, however, clinical trials have not confirmed this. There is a violation of metal homeostasis, which contributes to cognitive deficits and the development of neurodegeneration. Microglia, astrocytes and neurons are involved in the inflammatory process in Alzheimer's disease. There is a vicious circle when Aβ causes vascular insufficiency, which in turn leads to an increase in Aβ accumulation. Also there is evidence of a direct relationship between oxidative stress and neuronal dysfunction. Undoubtedly, pathogenic proteins, including Aβ-peptide, tau-peptide and proteins of the S100 family, play a leading role in the development of Alzheimer's disease. Despite numerous studies, the causal or consequential role of various pathological factors and changes in Alzheimer's disease is still ambiguous and inconsistent. All this gives grounds for further scientific research in this direction.


2019 ◽  
Author(s):  
Jonathan D Rudge

This paper describes a potential new explanation for Alzheimer’s disease (AD), referred to here as the lipid-invasion model. It proposes that AD is primarily caused by the influx of lipids following the breakdown of the blood brain barrier (BBB). The model argues that a principal role of the BBB is to protect the brain from external lipid access. When the BBB is damaged, it allows a mass influx of (mainly albumin-bound) free fatty acids (FFAs) and lipid-rich lipoproteins to the brain, which in turn causes neurodegeneration, amyloidosis, tau tangles and other AD characteristics. The model also argues that, whilst β-amyloid causes neurodegeneration, as is widely argued, its principal role in the disease lies in damaging the BBB. It is the external lipids, entering as a consequence, that are the primary drivers of neurodegeneration in AD., especially FFAs, which induce oxidative stress, stimulate microglia-driven neuroinflammation, and inhibit neurogenesis. Simultaneously, the larger, more lipid-laden lipoproteins, characteristic of the external plasma but not the CNS, cause endosomal-lysosomal abnormalities, amyloidosis and the formation of tau tangles, all characteristic of AD. In most cases (certainly in late-onset, noninherited forms of the disease) amyloidosis and tau tangle formation are consequences of this external lipid invasion, and in many ways more symptomatic of the disease than causative. In support of this, it is argued that the pattern of damage caused by the influx of FFAs into the brain is likely to resemble the neurodegeneration seen in alcohol-related brain damage (ARBD), a disease that shows many similarities to AD, including the areas of the brain it affects. The fact that neurodegeneration is far more pronounced in AD than in ARBD, and characterised by other features, such as amyloidosis and tau tangles, most likely results from the greater heterogeneity of the lipid assault in AD compared with ethanol alone. The lipid-invasion model, described here, arguably provides the first cohesive, multi-factorial explanation of AD that accounts for all currently known major risk factors, and explains all AD-associated pathologies, including those, such as endosomal-lysosomal dysfunction and excessive lipid droplet formation, that are not well-accounted for in other explanation of this disease.


2019 ◽  
Author(s):  
Jonathan D Rudge

This paper describes a potential new explanation for Alzheimer’s disease (AD), referred to here as the lipid-invasion model. It proposes that AD is primarily caused by the influx of lipids following the breakdown of the blood brain barrier (BBB). The model argues that a principal role of the BBB is to protect the brain from external lipid access. When the BBB is damaged, it allows a mass influx of (mainly albumin-bound) free fatty acids (FFAs) and lipid-rich lipoproteins to the brain, which in turn causes neurodegeneration, amyloidosis, tau tangles and other AD characteristics. The model also argues that, whilst β-amyloid causes neurodegeneration, as is widely argued, its principal role in the disease lies in damaging the BBB. It is the external lipids, entering as a consequence, that are the primary drivers of neurodegeneration in AD., especially FFAs, which induce oxidative stress, stimulate microglia-driven neuroinflammation, and inhibit neurogenesis. Simultaneously, the larger, more lipid-laden lipoproteins, characteristic of the external plasma but not the CNS, cause endosomal-lysosomal abnormalities, amyloidosis and the formation of tau tangles, all characteristic of AD. In most cases (certainly in late-onset, noninherited forms of the disease) amyloidosis and tau tangle formation are consequences of this external lipid invasion, and in many ways more symptomatic of the disease than causative. In support of this, it is argued that the pattern of damage caused by the influx of FFAs into the brain is likely to resemble the neurodegeneration seen in alcohol-related brain damage (ARBD), a disease that shows many similarities to AD, including the areas of the brain it affects. The fact that neurodegeneration is far more pronounced in AD than in ARBD, and characterised by other features, such as amyloidosis and tau tangles, most likely results from the greater heterogeneity of the lipid assault in AD compared with ethanol alone. The lipid-invasion model, described here, arguably provides the first cohesive, multi-factorial explanation of AD that accounts for all currently known major risk factors, and explains all AD-associated pathologies, including those, such as endosomal-lysosomal dysfunction and excessive lipid droplet formation, that are not well-accounted for in other explanation of this disease.


Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2347
Author(s):  
Anna Atlante ◽  
Giuseppina Amadoro ◽  
Antonella Bobba ◽  
Valentina Latina

A new epoch is emerging with intense research on nutraceuticals, i.e., “food or food product that provides medical or health benefits including the prevention and treatment of diseases”, such as Alzheimer’s disease. Nutraceuticals act at different biochemical and metabolic levels and much evidence shows their neuroprotective effects; in particular, they are able to provide protection against mitochondrial damage, oxidative stress, toxicity of β-amyloid and Tau and cell death. They have been shown to influence the composition of the intestinal microbiota significantly contributing to the discovery that differential microorganisms composition is associated with the formation and aggregation of cerebral toxic proteins. Further, the routes of interaction between epigenetic mechanisms and the microbiota–gut–brain axis have been elucidated, thus establishing a modulatory role of diet-induced epigenetic changes of gut microbiota in shaping the brain. This review examines recent scientific literature addressing the beneficial effects of some natural products for which mechanistic evidence to prevent or slowdown AD are available. Even if the road is still long, the results are already exceptional.


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