scholarly journals Role of Withaferin A and Its Derivatives in the Management of Alzheimer’s Disease: Recent Trends and Future Perspectives

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3696
Author(s):  
Rajib Das ◽  
Abdur Rauf ◽  
Saima Akhter ◽  
Mohammad Nazmul Islam ◽  
Talha Bin Emran ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Therapeutic Potential ◽  
Biological Effects ◽  
Amyloid Plaque ◽  
Beta Amyloid ◽  
Withaferin A ◽  
Protein Accumulation ◽  
Age Related

Globally, Alzheimer’s disease (AD) is one of the most prevalent age-related neurodegenerative disorders associated with cognitive decline and memory deficits due to beta-amyloid deposition (Aβ) and tau protein hyperphosphorylation. To date, approximately 47 million people worldwide have AD. This figure will rise to an estimated 75.6 million by 2030 and 135.5 million by 2050. According to the literature, the efficacy of conventional medications for AD is statistically substantial, but clinical relevance is restricted to disease slowing rather than reversal. Withaferin A (WA) is a steroidal lactone glycowithanolides, a secondary metabolite with comprehensive biological effects. Biosynthetically, it is derived from Withania somnifera (Ashwagandha) and Acnistus breviflorus (Gallinero) through the mevalonate and non-mevalonate pathways. Mounting evidence shows that WA possesses inhibitory activities against developing a pathological marker of Alzheimer’s diseases. Several cellular and animal models’ particulates to AD have been conducted to assess the underlying protective effect of WA. In AD, the neuroprotective potential of WA is mediated by reduction of beta-amyloid plaque aggregation, tau protein accumulation, regulation of heat shock proteins, and inhibition of oxidative and inflammatory constituents. Despite the various preclinical studies on WA’s therapeutic potentiality, less is known regarding its definite efficacy in humans for AD. Accordingly, the present study focuses on the biosynthesis of WA, the epidemiology and pathophysiology of AD, and finally the therapeutic potential of WA for the treatment and prevention of AD, highlighting the research and augmentation of new therapeutic approaches. Further clinical trials are necessary for evaluating the safety profile and confirming WA’s neuroprotective potency against AD.

scholarly journals A novel orally active HDAC6 inhibitor T-518 shows a therapeutic potential for Alzheimer’s disease and tauopathy in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomohiro Onishi ◽  
Ryouta Maeda ◽  
Michiko Terada ◽  
Sho Sato ◽  
Takahiro Fujii ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Therapeutic Potential ◽  
Drug Candidate ◽  
Histone Deacetylase 6 ◽  
Cellular Assays ◽  
Age Related ◽  
Acetylation State ◽  
Hdac6 Inhibitor ◽  
Orally Active

AbstractAccumulation of tau protein is a key pathology of age-related neurodegenerative diseases such as Alzheimer's disease and progressive supranuclear palsy. Those diseases are collectively termed tauopathies. Tau pathology is associated with axonal degeneration because tau binds to microtubules (MTs), a component of axon and regulates their stability. The acetylation state of MTs contributes to stability and histone deacetylase 6 (HDAC6) is a major regulator of MT acetylation status, suggesting that pharmacological HDAC6 inhibition could improve axonal function and may slow the progression of tauopathy. Here we characterize N-[(1R,2R)-2-{3-[5-(difluoromethyl)-1,3,4-oxadiazol-2-yl]-5-oxo-5H,6H,7H-pyrrolo[3,4-b]pyridin-6-yl}cyclohexyl]-2,2,3,3,3-pentafluoropropanamide (T-518), a novel, potent, highly selective HDAC6 inhibitor with clinically favorable pharmacodynamics. T-518 shows potent inhibitory activity against HDAC6 and superior selectivity over other HDACs compared with the known HDAC6 inhibitors in the enzyme and cellular assays. T-518 showed brain penetration in an oral dose and blocked HDAC6-dependent tubulin deacetylation at Lys40 in mouse hippocampus. A 2-week treatment restored impaired axonal transport and novel object recognition in the P301S tau Tg mouse, tauopathy model, while a 3-month treatment also decreased RIPA-insoluble tau accumulation. Pharmaceutical inhibition of HDAC6 is a potential therapeutic strategy for tauopathy, and T-518 is a particularly promising drug candidate.

scholarly journals Signaling Mechanisms of Selective PPARγ Modulators in Alzheimer’s Disease

PPAR Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Manoj Govindarajulu ◽  
Priyanka D. Pinky ◽  
Jenna Bloemer ◽  
Nila Ghanei ◽  
Vishnu Suppiramaniam ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Adverse Effects ◽  
Therapeutic Potential ◽  
Protein Accumulation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Continuous Increase ◽  
Therapeutic Benefits ◽  
The Brain

Alzheimer’s disease (AD) is a chronic neurodegenerative disease characterized by abnormal protein accumulation, synaptic dysfunction, and cognitive impairment. The continuous increase in the incidence of AD with the aged population and mortality rate indicates the urgent need for establishing novel molecular targets for therapeutic potential. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists such as rosiglitazone and pioglitazone reduce amyloid and tau pathologies, inhibit neuroinflammation, and improve memory impairments in several rodent models and in humans with mild-to-moderate AD. However, these agonists display poor blood brain barrier permeability resulting in inadequate bioavailability in the brain and thus requiring high dosing with chronic time frames. Furthermore, these dosing levels are associated with several adverse effects including increased incidence of weight gain, liver abnormalities, and heart failure. Therefore, there is a need for identifying novel compounds which target PPARγ more selectively in the brain and could provide therapeutic benefits without a high incidence of adverse effects. This review focuses on how PPARγ agonists influence various pathologies in AD with emphasis on development of novel selective PPARγ modulators.

AADVAC1, AN ACTIVE IMMUNOTHERAPY FOR ALZHEIMER’S DISEASE AND NON ALZHEIMER TAUOPATHIES: AN OVERVIEW OF PRECLINICAL AND CLINICAL DEVELOPMENT

2018 ◽  
pp. 1-7
Author(s):  
P. Novak ◽  
N. Zilka ◽  
M. Zilkova ◽  
B. Kovacech ◽  
R. Skrabana ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Neurodegenerative Disorder ◽  
Therapeutic Potential ◽  
Phase 1 ◽  
Primary Progressive Aphasia ◽  
Tau Proteins ◽  
Active Immunotherapy ◽  
Tau Pathology

Neurofibrillary tau protein pathology is closely associated with the progression and phenotype of cognitive decline in Alzheimer’s disease and other tauopathies, and a high-priority target for disease-modifying therapies. Herein, we provide an overview of the development of AADvac1, an active immunotherapy against tau pathology, and tau epitopes that are potential targets for immunotherapy. The vaccine leads to the production of antibodies that target conformational epitopes in the microtubule-binding region of tau, with the aim to prevent tau aggregation and spreading of pathology, and promote tau clearance. The therapeutic potential of the vaccine was evaluated in transgenic rats and mice expressing truncated, non mutant tau protein, which faithfully replicate of human tau pathology. Treatment with AADvac1 resulted in reduction of neurofibrillary pathology and insoluble tau in their brains, and amelioration of their deleterious phenotype. The vaccine was highly immunogenic in humans, inducing production of IgG antibodies against the tau peptide in 29/30 treated elderly patients with mild-to-moderate Alzheimer’s. These antibodies were able to recognise insoluble tau proteins in Alzheimer patients’ brains. Treatment with AADvac1 proved to be remarkably safe, with injection site reactions being the only adverse event tied to treatment. AADvac1 is currently being investigated in a phase 2 study in Alzheimer’s disease, and a phase 1 study in non-fluent primary progressive aphasia, a neurodegenerative disorder with a high tau pathology component.

scholarly journals Therapeutic potential of astaxanthin and superoxide dismutase in Alzheimer's disease

Open Biology ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 210013
Author(s):  
Vyshnavy Balendra ◽  
Sandeep Kumar Singh
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Superoxide Dismutase ◽  
Antioxidant System ◽  
Tau Protein ◽  
Therapeutic Potential ◽  
Plaque Burden ◽  
Memory Decline ◽  
Endogenous Antioxidants ◽  
The Brain

Oxidative stress, the imbalance of the antioxidant system, results in an accumulation of neurotoxic proteins in Alzheimer's disease (AD). The antioxidant system is composed of exogenous and endogenous antioxidants to maintain homeostasis. Superoxide dismutase (SOD) is an endogenous enzymatic antioxidant that converts superoxide ions to hydrogen peroxide in cells. SOD supplementation in mice prevented cognitive decline in stress-induced cells by reducing lipid peroxidation and maintaining neurogenesis in the hippocampus. Furthermore, SOD decreased expression of BACE1 while reducing plaque burden in the brain. Additionally, Astaxanthin (AST), a potent exogenous carotenoid, scavenges superoxide anion radicals. Mice treated with AST showed slower memory decline and decreased depositions of amyloid-beta (A β ) and tau protein. Currently, the neuroprotective potential of these supplements has only been examined separately in studies. However, a single antioxidant cannot sufficiently resist oxidative damage to the brain, therefore, a combinatory approach is proposed as a relevant therapy for ameliorating pathological changes in AD.

scholarly journals Inflammation and Oxidative Stress: The Molecular Connectivity between Insulin Resistance, Obesity, and Alzheimer’s Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Giuseppe Verdile ◽  
Kevin N. Keane ◽  
Vinicius F. Cruzat ◽  
Sandra Medic ◽  
Miheer Sabale ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Insulin Resistance ◽  
Alzheimer's Disease ◽  
Insulin Signalling ◽  
Contributory Factor ◽  
Protein Accumulation ◽  
Age Related ◽  
Impaired Insulin ◽  
And Oxidative Stress

Type 2 diabetes (T2DM), Alzheimer’s disease (AD), and insulin resistance are age-related conditions and increased prevalence is of public concern. Recent research has provided evidence that insulin resistance and impaired insulin signalling may be a contributory factor to the progression of diabetes, dementia, and other neurological disorders. Alzheimer’s disease (AD) is the most common subtype of dementia. Reduced release (for T2DM) and decreased action of insulin are central to the development and progression of both T2DM and AD. A literature search was conducted to identify molecular commonalities between obesity, diabetes, and AD. Insulin resistance affects many tissues and organs, either through impaired insulin signalling or through aberrant changes in both glucose and lipid (cholesterol and triacylglycerol) metabolism and concentrations in the blood. Although epidemiological and biological evidence has highlighted an increased incidence of cognitive decline and AD in patients with T2DM, the common molecular basis of cell and tissue dysfunction is rapidly gaining recognition. As a cause or consequence, the chronic inflammatory response and oxidative stress associated with T2DM, amyloid-β(Aβ) protein accumulation, and mitochondrial dysfunction link T2DM and AD.

scholarly journals Amyloid-β dimers in the absence of plaque pathology impair learning and synaptic plasticity

Brain ◽  
2015 ◽  
Vol 139 (2) ◽  
pp. 509-525 ◽  
Author(s):  
Andreas Müller-Schiffmann ◽  
Arne Herring ◽  
Laila Abdel-Hafiz ◽  
Aisa N. Chepkova ◽  
Sandra Schäble ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Learning And Memory ◽  
Biological Effects ◽  
Amyloid Β ◽  
Long Term Potentiation ◽  
Amyloid Β Peptide ◽  
Age Related ◽  
Plaque Pathology

Abstract Despite amyloid plaques, consisting of insoluble, aggregated amyloid-β peptides, being a defining feature of Alzheimer’s disease, their significance has been challenged due to controversial findings regarding the correlation of cognitive impairment in Alzheimer’s disease with plaque load. The amyloid cascade hypothesis defines soluble amyloid-β oligomers, consisting of multiple amyloid-β monomers, as precursors of insoluble amyloid-β plaques. Dissecting the biological effects of single amyloid-β oligomers, for example of amyloid-β dimers, an abundant amyloid-β oligomer associated with clinical progression of Alzheimer’s disease, has been difficult due to the inability to control the kinetics of amyloid-β multimerization. For investigating the biological effects of amyloid-β dimers, we stabilized amyloid-β dimers by an intermolecular disulphide bridge via a cysteine mutation in the amyloid-β peptide (Aβ-S8C) of the amyloid precursor protein. This construct was expressed as a recombinant protein in cells and in a novel transgenic mouse, termed tgDimer mouse. This mouse formed constant levels of highly synaptotoxic soluble amyloid-β dimers, but not monomers, amyloid-β plaques or insoluble amyloid-β during its lifespan. Accordingly, neither signs of neuroinflammation, tau hyperphosphorylation or cell death were observed. Nevertheless, these tgDimer mice did exhibit deficits in hippocampal long-term potentiation and age-related impairments in learning and memory, similar to what was observed in classical Alzheimer’s disease mouse models. Although the amyloid-β dimers were unable to initiate the formation of insoluble amyloid-β aggregates in tgDimer mice, after crossbreeding tgDimer mice with the CRND8 mouse, an amyloid-β plaque generating mouse model, Aβ-S8C dimers were sequestered into amyloid-β plaques, suggesting that amyloid-β plaques incorporate neurotoxic amyloid-β dimers that by themselves are unable to self-assemble. Our results suggest that within the fine interplay between different amyloid-β species, amyloid-β dimer neurotoxic signalling, in the absence of amyloid-β plaque pathology, may be involved in causing early deficits in synaptic plasticity, learning and memory that accompany Alzheimer’s disease. 10.1093/brain/awv355_video_abstract awv355_video_abstract

scholarly journals Beta-Amyloid Precursor Protein (βAPP) Processing in Alzheimer’s Disease (AD) and Age-Related Macular Degeneration (AMD)

2014 ◽  
Vol 52 (1) ◽  
pp. 533-544 ◽  
Author(s):  
Yuhai Zhao ◽  
Surjyadipta Bhattacharjee ◽  
Brandon M. Jones ◽  
James M. Hill ◽  
Christian Clement ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Precursor Protein ◽  
Macular Degeneration ◽  
Beta Amyloid ◽  
Precursor Protein ◽  
Age Related Macular Degeneration ◽  
Age Related
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