scholarly journals Exploitation of Marine Molecules to Manage Alzheimer’s Disease

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 373
Author(s):  
Marisa Silva ◽  
Paula Seijas ◽  
Paz Otero

Neurodegenerative diseases are sociosanitary challenges of today, as a result of increased average life expectancy, with Alzheimer’s disease being one of the most prevalent. This pathology is characterized by brain impairment linked to a neurodegenerative process culminating in cognitive decline and behavioral disorders. Though the etiology of this pathology is still unknown, it is usually associated with the appearance of senile plaques and neurofibrillary tangles. The most used prophylaxis relies on anticholinesterase drugs and NMDA receptor antagonists, whose main action is to relieve symptoms and not to treat or prevent the disease. Currently, the scientific community is gathering efforts to disclose new natural compounds effective against Alzheimer’s disease and other neurodegenerative pathologies. Marine natural products have been shown to be promising candidates, and some have been proven to exert a high neuroprotection effect, constituting a large reservoir of potential drugs and nutraceutical agents. The present article attempts to describe the processes of extraction and isolation of bioactive compounds derived from sponges, algae, marine bacteria, invertebrates, crustaceans, and tunicates as drug candidates against AD, with a focus on the success of pharmacological activity in the process of finding new and effective drug compounds.

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuan-Yuan Chen ◽  
Min-Chang Wang ◽  
Yan-Ni Wang ◽  
He-He Hu ◽  
Qing-Quan Liu ◽  
...  

Abstract Aging and average life expectancy have been increasing at a rapid rate, while there is an exponential risk to suffer from brain-related frailties and neurodegenerative diseases as the population ages. Alzheimer’s disease (AD) is the most common neurodegenerative disease worldwide with a projected expectation to blossom into the major challenge in elders and the cases are forecasted to increase about 3-fold in the next 40 years. Considering the etiological factors of AD are too complex to be completely understood, there is almost no effective cure to date, suggesting deeper pathomechanism insights are urgently needed. Metabolites are able to reflect the dynamic processes that are in progress or have happened, and metabolomic may therefore provide a more cost-effective and productive route to disease intervention, especially in the arena for pathomechanism exploration and new biomarker identification. In this review, we primarily focused on how redox signaling was involved in AD-related pathologies and the association between redox signaling and altered metabolic pathways. Moreover, we also expatiated the main redox signaling-associated mechanisms and their cross-talk that may be amenable to mechanism-based therapies. Five natural products with promising efficacy on AD inhibition and the benefit of AD intervention on its complications were highlighted as well. Graphical Abstract


2020 ◽  
Vol 26 ◽  
Author(s):  
Md. Sahab Uddin ◽  
Sharifa Hasana ◽  
Jamil Ahmad ◽  
Md. Farhad Hossain ◽  
Md. Mosiqur Rahman ◽  
...  

: Alzheimer's disease (AD) is an irrevocable chronic brain disorder featured by neuronal loss, microglial accumulation, and progressive cognitive impairment. The proper pathophysiology of this life-threatening disorder is not completely understood and no exact remedies are found yet. Over the last few decades, research on AD has mainly highlighted in pathomechanisms linked to a couple of the major pathological hallmarks, including extracellular senile plaques, made of amyloid-β (Aβ) peptides, and intracellular neurofibrillary tangles (NFTs), made of tau proteins. Aβ can induce apoptosis, trigger an inflammatory response, and inhibit the synaptic plasticity of the hippocampus, which ultimately contributes to reducing cognitive functions and memory impairment. Recently, a third disease hallmark, the neuroinflammatory reaction that is mediated by cerebral innate immune cells, has become a spotlight in the current research area, assured by pre-clinical, clinical, and genetic investigations. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a cytokine producer, is significantly associated with physiological inflammatory proceedings and thus showing a promising candidate for inflammation-based AD therapy. Recent data reveal that phytochemicals mainly polyphenols compounds exhibit potential neuroprotective functions and it may be considered as a vital resource for discovering several drug candidates against AD. Interestingly, phytochemicals can easily interfere with the signaling pathway of NF-κB. This review represents the anti-neuroinflammatory potential of polyphenols as inhibitors of NF-κB to combat AD pathogenesis.


2016 ◽  
Vol 21 (2) ◽  
pp. 116-125
Author(s):  
İsmail Birincioğlu ◽  
Mustafa Uzun ◽  
Nevzat Alkan ◽  
Ömer Kurtaş ◽  
Rıza Yılmaz ◽  
...  

Handwriting and signature comparisons are frequently performed in forensic investigations of documents. Mistakes in conclusion might be due to lack of sufficient documentation and information. Many factors can affect handwriting and signature. These factors are divided into two groups: dependent or independent of the individual at the time the handwriting or signature is made. Therefore, the situations leading to differences between individuals and in the individual’s own handwriting and signature should be determined. Currently, average life expectancy and quality have increased due to the developments in health services. Thus, an increasing number of elderly people are engaged in an active daily life and trade. Alzheimer’s Disease (AD) can develop in the elderly; this is a condition that could alter handwriting and signature considerably over time.In forensic document examination, comparing the document in question containing handwriting or signature with the original documents prepared before the document in question was prepared is important. However, if alterations have developed secondary to a disease, the documents prepared before and after the disease affected the individual should be assessed together.Likewise, in the present case, the examiners making comparisons using handwriting and signatures from different periods reached entirely different conclusions.The case is a bill prepared in 1994. The payee of the bill is a male born in 1925 and diagnosed with AD shortly before his death in 1998. The indebted person in the bill is the payee’s spouse. For the assessment of handwriting and signature, the first endorsement consisting of the handwritten name and signature was used. Several expert reports regarding the same document had been commissioned; these reached different views. The document was sent to The Council of Forensic Medicine to assess the identification and the previous reports. After re-evaluation, the handwriting was declared to belong to the payee.In this study, the reason that the experts delivered opposing opinions on the identification of a document handwritten by a person with AD after being referred to court was investigated.Based on the judicial file, the document examiners did not have the opportunity to evaluate all factors affecting the handwriting or signature of the individual, and an adequate number of handwriting and signature examples were not collected for comparison. Consequently, the examiners reached differing opinions. Thus, the above-mentioned factors are necessary to derive a satisfactory and accurate opinion regarding the identification of handwriting or signature.Keywords: Forensic sciences, handwriting, signature, Alzheimer’s Disease.


2013 ◽  
Vol 59 (1) ◽  
pp. 5-24 ◽  
Author(s):  
E.V. Kugaevskaya

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system, leading to dementia. The basis of AD is neurodegenerative process that leads to death of neurons in the cerebral cortex. This neurodegenerative process is associated with the formation of neurofibrillary tangles in the brain and the deposition of senile plaques, the main component of which is a beta-amyloid peptide (Ab). Risk factors for AD are age, as well as hypertension, atherosclerosis, diabetes and hypercholesterolemia in the pathogenesis of which involved angiotensin converting enzyme (ACE) – key enzyme of the renin-angiotensin (RAS) and kallikrein-kinin (KKS) systems. Recently it was discovered that ACE, along with other metallopeptidases, participates in the metabolism of Ab, cleaving the bonds at the N-terminal and C-terminal region of the molecule Ab. The role of the ACE in the degradation processes of Ab takes an interest. It is associated with the fact that the using of ACE inhibitors is the main therapeutic approach used in the treatment of various forms of hypertension and other cardiovascular diseases. However, until now not been resolved, can be used antihypertensive drugs that inhibit RAS for the treatment or prevention of AD. Currently, there are numerous studies on finding the relationship between RAS and AD.


2018 ◽  
Vol 1 (3) ◽  
pp. e00015 ◽  
Author(s):  
S.O. Bachurin ◽  
E.V. Bovina ◽  
A.A. Ustyugov

Intracellular and extracellular accumulation of fibrillary proteins, beta-amyloid and hyperphosphorylated Tau, in patients with Alzheimer’s disease (AD) leads to chronic and progressive neurodegenerative process. Overaccumulation of aggregates results in synaptic dysfunction and inevitable neuronal loss. Although the exact molecular pathways of the AD still require better understanding, it is clear this neuropathology is a multifactorial disorder where the advanced age is the main risk factor. Lately, several dozens of drug candidates have succeeded to phase II clinical trials; however, none has passed phase III. In this review we summarize existing data on anti-AD therapeutic agents currently undergoing clinical trials and included in the public websites www.clinicaltrials.gov and Alzforum.org as well as the Thomson Reuters «Integrity» database. We revealed three major trends in AD drug discovery. First, developing of “disease-modifying agents” could potentially slow the progression of structural and functional abnormalities in the central nervous system providing sustainable improvements of cognitive functions, which persist even after drug withdrawal. Secondly, the focused design of multitargeted drugs acting on multiple key molecular pathways. Finally, the repositioning of drugs that are already available on the market for the novel (anti-AD) application provides a promising strategy for finishing clinical trials and re-marketing.


2014 ◽  
Vol 56 ◽  
pp. 99-110 ◽  
Author(s):  
David Allsop ◽  
Jennifer Mayes

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.


2020 ◽  
Vol 20 (9) ◽  
pp. 770-781 ◽  
Author(s):  
Poornima Sharma ◽  
Anjali Sharma ◽  
Faizana Fayaz ◽  
Sharad Wakode ◽  
Faheem H. Pottoo

Alzheimer’s disease (AD) is the most prevalent and severe neurodegenerative disease affecting more than 0.024 billion people globally, more common in women as compared to men. Senile plaques and amyloid deposition are among the main causes of AD. Amyloid deposition is considered as a central event which induces the link between the production of β amyloid and vascular changes. Presence of numerous biomarkers such as cerebral amyloid angiopathy, microvascular changes, senile plaques, changes in white matter, granulovascular degeneration specifies the manifestation of AD while an aggregation of tau protein is considered as a primary marker of AD. Likewise, microvascular changes, activation of microglia (immune defense system of CNS), amyloid-beta aggregation, senile plaque and many more biomarkers are nearly found in all Alzheimer’s patients. It was seen that 70% of Alzheimer’s cases occur due to genetic factors. It has been reported in various studies that apolipoprotein E(APOE) mainly APOE4 is one of the major risk factors for the later onset of AD. Several pathological changes also occur in the white matter which include dilation of the perivascular space, loss of axons, reactive astrocytosis, oligodendrocytes and failure to drain interstitial fluid. In this review, we aim to highlight the various biological signatures associated with the AD which may further help in discovering multitargeting drug therapy.


2020 ◽  
Vol 20 (26) ◽  
pp. 2380-2390 ◽  
Author(s):  
Md. Sahab Uddin ◽  
Abdullah Al Mamun ◽  
Md. Ataur Rahman ◽  
Tapan Behl ◽  
Asma Perveen ◽  
...  

Objective: Alzheimer's disease (AD) is a devastating neurodegenerative disorder, characterized by the extracellular accumulations of amyloid beta (Aβ) as senile plaques and intracellular aggregations of tau in the form of neurofibrillary tangles (NFTs) in specific brain regions. In this review, we focus on the interaction of Aβ and tau with cytosolic proteins and several cell organelles as well as associated neurotoxicity in AD. Summary: Misfolded proteins present in cells accompanied by correctly folded, intermediately folded, as well as unfolded species. Misfolded proteins can be degraded or refolded properly with the aid of chaperone proteins, which are playing a pivotal role in protein folding, trafficking as well as intermediate stabilization in healthy cells. The continuous aggregation of misfolded proteins in the absence of their proper clearance could result in amyloid disease including AD. The neuropathological changes of AD brain include the atypical cellular accumulation of misfolded proteins as well as the loss of neurons and synapses in the cerebral cortex and certain subcortical regions. The mechanism of neurodegeneration in AD that leads to severe neuronal cell death and memory dysfunctions is not completely understood until now. Conclusion: Examining the impact, as well as the consequences of protein misfolding, could help to uncover the molecular etiologies behind the complicated AD pathogenesis.


2020 ◽  
Vol 13 (4) ◽  
pp. 273-294 ◽  
Author(s):  
Elahe Zarini-Gakiye ◽  
Javad Amini ◽  
Nima Sanadgol ◽  
Gholamhassan Vaezi ◽  
Kazem Parivar

Background: Alzheimer’s disease (AD) is the most frequent subtype of incurable neurodegenerative dementias and its etiopathology is still not clearly elucidated. Objective: Outline the ongoing clinical trials (CTs) in the field of AD, in order to find novel master regulators. Methods: We strictly reviewed all scientific reports from Clinicaltrials.gov and PubMed databases from January 2010 to January 2019. The search terms were “Alzheimer's disease” or “dementia” and “medicine” or “drug” or “treatment” and “clinical trials” and “interventions”. Manuscripts that met the objective of this study were included for further evaluations. Results: Drug candidates have been categorized into two main groups including antibodies, peptides or hormones (such as Ponezumab, Interferon β-1a, Solanezumab, Filgrastim, Levemir, Apidra, and Estrogen), and naturally-derived ingredients or small molecules (such as Paracetamol, Ginkgo, Escitalopram, Simvastatin, Cilostazo, and Ritalin-SR). The majority of natural candidates acted as anti-inflammatory or/and anti-oxidant and antibodies exert their actions via increasing amyloid-beta (Aβ) clearance or decreasing Tau aggregation. Among small molecules, most of them that are present in the last phases act as specific antagonists (Suvorexant, Idalopirdine, Intepirdine, Trazodone, Carvedilol, and Risperidone) or agonists (Dextromethorphan, Resveratrol, Brexpiprazole) and frequently ameliorate cognitive dysfunctions. Conclusion: The presences of a small number of candidates in the last phase suggest that a large number of candidates have had an undesirable side effect or were unable to pass essential eligibility for future phases. Among successful treatment approaches, clearance of Aβ, recovery of cognitive deficits, and control of acute neuroinflammation are widely chosen. It is predicted that some FDA-approved drugs, such as Paracetamol, Risperidone, Escitalopram, Simvastatin, Cilostazoand, and Ritalin-SR, could also be used in off-label ways for AD. This review improves our ability to recognize novel treatments for AD and suggests approaches for the clinical trial design for this devastating disease in the near future.


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