scholarly journals Centella asiatica Protects d-Galactose/AlCl3 Mediated Alzheimer’s Disease-Like Rats via PP2A/GSK-3β Signaling Pathway in Their Hippocampus

2019 ◽  
Vol 20 (8) ◽  
pp. 1871 ◽  
Author(s):  
Samaila Musa Chiroma ◽  
Mohamad Taufik Hidayat Baharuldin ◽  
Che Norma Mat Taib ◽  
Zulkhairi Amom ◽  
Saravanan Jagadeesan ◽  
...  

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder more prevalent among the elderly population. AD is characterised clinically by a progressive decline in cognitive functions and pathologically by the presence of neurofibrillary tangles (NFTs), deposition of beta-amyloid (Aβ) plaque and synaptic dysfunction in the brain. Centella asiatica (CA) is a valuable herb being used widely in African, Ayurvedic, and Chinese traditional medicine to reverse cognitive impairment and to enhance cognitive functions. This study aimed to evaluate the effectiveness of CA in preventing d-galactose/aluminium chloride (d-gal/AlCl3) induced AD-like pathologies and the underlying mechanisms of action were further investigated for the first time. Results showed that co-administration of CA to d-gal/AlCl3 induced AD-like rat models significantly increased the levels of protein phosphatase 2 (PP2A) and decreased the levels of glycogen synthase kinase-3 beta (GSK-3β). It was further observed that, CA increased the expression of mRNA of Bcl-2, while there was minimal effect on the expression of caspase 3 mRNA. The results also showed that, CA prevented morphological aberrations in the connus ammonis 3 (CA 3) sub-region of the rat’s hippocampus. The results clearly demonstrated for the first time that CA could alleviate d-gal/AlCl3 induced AD-like pathologies in rats via inhibition of hyperphosphorylated tau (P-tau) bio-synthetic proteins, anti-apoptosis and maintenance of cytoarchitecture.

2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Maja Jembrek ◽  
Mirjana Babić ◽  
Nela Pivac ◽  
Patrick Hof ◽  
Goran Šimić

AbstractAlzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by the extracellular deposits of β amyloid peptides (Aβ) in senile plaques, and intracellular aggregates of hyperphosphorylated tau in neurofibrillary tangles (NFT). Although accumulation of Aβ has been long considered a leading hypothesis in the disease pathology, it is increasingly evident that the role hyperphosphorylation of tau in destabilization of microtubule assembly and disturbance of axonal transport is equally detrimental in the neurodegenerative process. The main kinase involved in phosphorylation of tau is glycogen-synthase kinase 3-beta (GSK-3β). Intracellular accumulation of Aβ also likely induces increase in hyperphosphorylated tau by a mechanism dependent on GSK-3β. In addition, Aβ affects production of ceramides, the major sphingolipids in mammalian cells, by acting on sphingomyelinases, enzymes responsible for the catabolic formation of ceramides from the sphingomyelin. Generated ceramides in turn increase production of Aβ by acting on β-secretase, a key enzyme in the proteolytic processing of the amyloid precursor protein (APP), altogether leading to a ceramide-Aβ-hyperphosphorylated tau cascade that ends in neuronal death. Modulators and inhibitors acting on members of this devastating cascade are considered as potential targets for AD therapy. There is still no adequate treatment for AD patients. Novel therapeutic strategies increasingly consider the combination of multiple targets and interactions among the key members of implicated molecular pathways. This review summarizes recent findings and therapeutic perspectives in the pathology and treatment of AD, with the emphasis on the interplay between hyperphosphorylated tau, amyloid β, and sphingolipid mediators.


2018 ◽  
Vol 25 (26) ◽  
pp. 3141-3159 ◽  
Author(s):  
Leide Caroline dos Santos Picanco ◽  
Priscilla F. Ozela ◽  
Maiara de Fatima de Brito Brito ◽  
Abraao A. Pinheiro ◽  
Elias C. Padilha ◽  
...  

Dementia is characterized by the impairment of cognition and behavior of people over 65 years. Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder in the world, as approximately 47 million people are affected by this disease and the tendency is that this number will increase to 62% by 2030. Two microscopic features assist in the characterization of the disease, the amyloid plaques and neurofibrillary agglomerates. All these factors are responsible for the slow and gradual deterioration of memory that affect language, personality or cognitive control. For the AD diagnosis, neuropsychological tests are performed in different spheres of cognitive functions but since not all cognitive functions may be affected, cerebrospinal fluid biomarkers are used along with these tests. To date, cholinesterase inhibitors are used as treatment, they are the only drugs that have shown significant improvements in the cognitive functions of AD patients. Despite the proven effectiveness of cholinesterase inhibitors, an AD carrier, even while being treated, is continually subjected to progressive degeneration of the neuronal tissue. For this reason, other biochemical pathways associated with the pathophysiology of AD have been explored as alternatives to the treatment of this condition such as inhibition of β-secretase and glycogen synthase kinase-3β. The present study aims to conduct a review of the epidemiology, pathophysiology, symptoms, diagnosis and treatment of Alzheimer's disease, emphasizing the research and development of new therapeutic approaches.


2020 ◽  
Vol 6 (5) ◽  
pp. 1-7
Author(s):  
Chinonye A Maduagwuna ◽  

Study background: Chronic neuroinflammation is a common emerging hallmark of several neurodegenerative diseases. Alzheimer’s Disease (AD) is the most common cause of dementia among the elderly and is characterized by loss of memory and other cognitive functions.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Corona Solana ◽  
Raquel Tarazona ◽  
Rafael Solana

Alzheimer’s disease (AD) represents the most common cause of dementia in the elderly. AD is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although the aetiology of AD is not clear, both environmental factors and heritable predisposition may contribute to disease occurrence. In addition, inflammation and immune system alterations have been linked to AD. The prevailing hypothesis as cause of AD is the deposition in the brain of amyloid beta peptides (Aβ). Although Aβ have a role in defending the brain against infections, their accumulation promotes an inflammatory response mediated by microglia and astrocytes. The production of proinflammatory cytokines and other inflammatory mediators such as prostaglandins and complement factors favours the recruitment of peripheral immune cells further promoting neuroinflammation. Age-related inflammation and chronic infection with herpes virus such as cytomegalovirus may also contribute to inflammation in AD patients. Natural killer (NK) cells are innate lymphoid cells involved in host defence against viral infections and tumours. Once activated NK cells secrete cytokines such as IFN-γ and TNF-α and chemokines and exert cytotoxic activity against target cells. In the elderly, changes in NK cell compartment have been described which may contribute to the lower capacity of elderly individuals to respond to pathogens and tumours. Recently, the role of NK cells in the immunopathogenesis of AD is discussed. Although in AD patients the frequency of NK cells is not affected, a high NK cell response to cytokines has been described together with NK cell dysregulation of signalling pathways which is in part involved in this altered behaviour.


2020 ◽  
Vol 9 (1) ◽  
pp. 22-42
Author(s):  
Sunpreet Kaur ◽  
Puneet Kumar ◽  
Shamsher Singh

Background: Alzheimer’s disease is the most common neurodegenerative disorder affecting the elderly population and emerges as a leading challenge for the scientific research community. The wide pathological aspects of AD made it a multifactorial disorder and even after long time it’s difficult to treat due to unexplored etiological factors. Methods: The etiogenesis of AD includes mitochondrial failure, gut dysbiosis, biochemical alterations but deposition of amyloid-beta plaques and neurofibrillary tangles are implicated as major hallmarks of neurodegeneration in AD. The aggregates of these proteins disrupt neuronal signaling, enhance oxidative stress and reduce activity of various cellular enzymes which lead to neurodegeneration in the cerebral cortex, neocortex and hippocampus. The metals like copper, aluminum are involved in APP trafficking and promote amyloidbeta aggregation. Similarly, disturbed ubiquitin proteasomal system, autophagy and amyloid- beta clearance mechanisms exert toxic insult in the brain. Result and conclusion : The current review explored the role of oxidative stress in disruption of amyloid homeostasis which further leads to amyloid-beta plaque formation and subsequent neurodegeneration in AD. Presently, management of AD relies on the use of acetylcholinesterase inhibitors, antioxidants and metal chelators but they are not specific measures. Therefore, in this review, we have widely cited the various pathological mechanisms of AD as well as possible therapeutic targets.


2020 ◽  
Vol 21 (21) ◽  
pp. 8014
Author(s):  
Sudip Dhakal ◽  
Ian Macreadie

Alzheimer’s Disease (AD) is a progressive multifactorial age-related neurodegenerative disorder that causes the majority of deaths due to dementia in the elderly. Although various risk factors have been found to be associated with AD progression, the cause of the disease is still unresolved. The loss of proteostasis is one of the major causes of AD: it is evident by aggregation of misfolded proteins, lipid homeostasis disruption, accumulation of autophagic vesicles, and oxidative damage during the disease progression. Different models have been developed to study AD, one of which is a yeast model. Yeasts are simple unicellular eukaryotic cells that have provided great insights into human cell biology. Various yeast models, including unmodified and genetically modified yeasts, have been established for studying AD and have provided significant amount of information on AD pathology and potential interventions. The conservation of various human biological processes, including signal transduction, energy metabolism, protein homeostasis, stress responses, oxidative phosphorylation, vesicle trafficking, apoptosis, endocytosis, and ageing, renders yeast a fascinating, powerful model for AD. In addition, the easy manipulation of the yeast genome and availability of methods to evaluate yeast cells rapidly in high throughput technological platforms strengthen the rationale of using yeast as a model. This review focuses on the description of the proteostasis network in yeast and its comparison with the human proteostasis network. It further elaborates on the AD-associated proteostasis failure and applications of the yeast proteostasis network to understand AD pathology and its potential to guide interventions against AD.


2010 ◽  
Vol 5 (1) ◽  
pp. 12
Author(s):  
Daniela Galimberti ◽  
Chiara Fenoglio ◽  
Elio Scarpini ◽  
◽  
◽  
...  

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, whereas frontotemporal lobar degeneration (FTLD) is the most frequent neurodegenerative disorder with a pre-senile onset. The two major neuropathological hallmarks of AD are extracellular amyloid beta plaques and intracellular neurofibrillary tangles. In FTLD the deposition of tau has been observed in a number of cases, but in several brains there is no deposition of tau but instead a positivity for ubiquitin. In some families these diseases are inherited in an autosomal dominant fashion. Genes responsible for familial AD include the amyloid precursor protein (APP), presenilin 1 (PS1) and presenilin 2 (PS2), whereas the main genes responsible for familial FTLD are microtubule-associated protein tau gene (MAPT) and progranulin (GRN). Concerning sporadic AD, it is known that the presence of the ε4 allele of the apolipoprotein E gene is a susceptibility factor. A number of additional genetic factors contribute to susceptibility for AD and FTLD.


2013 ◽  
Vol 765-767 ◽  
pp. 256-260
Author(s):  
Yan Ling Zhang ◽  
Yuan Ming Wang ◽  
Yan Jiang Qiao

Multiple targets which closely related to Alzheimer's disease (AD) pathogenesis were selected for pharmacophore models generation and virtual screening in Chinese herbs. The targets comprised Acetylcholinesterase (AchE), muscarinic receptor 1 (M1), γ-secretase and glycogen synthase kinase 3β (GSK-3β). The pharmacophore models, which of AchE inhibitors, M1 agonists, γ-secretase inhibitors and GSK-3β inhibitors, were constructed by distance comparison method. Four testing databases for the evaluation of pharmacophore models were constructed with the active compounds with clearly marked activity on each target. The metric CAI (Comprehensive Appraisal Index) was then used to evaluate and obtain the best pharmacophore models of each target, which were then applied to screen the Traditional Chinese Medicine Database for potential active compounds in Chinese herbs. Four common used herbs were obtained, which contain the active compounds and can act on multiple targets, and were expected to have multiple activity of anti-AD disease.


2008 ◽  
Vol 21 (6) ◽  
pp. 755-771
Author(s):  
O. Schillaci ◽  
L. Travascio ◽  
C. Bruni ◽  
G. Bazzocchi ◽  
A. Testa ◽  
...  

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is the most common cause of dementia in the elderly. Magnetic resonance (MR) or computed tomography (CT) imaging is recommended for routine evaluation of dementias. The development of molecular imaging agents and the new techniques of MR for AD are critically important for early diagnosis, neuropathogenesis studies and assessing treatment efficacy in AD. Neuroimaging using nuclear medicine techniques such as SPECT, PET and MR spectroscopy has the potential to characterize the biomarkers for Alzheimer's disease. The present review summarizes the results of radionuclide imaging and MR imaging in AD.


2021 ◽  
Author(s):  
Fábio Dias Nogueira ◽  
Ana Klara Rodrigues Alves ◽  
Barbara Beatriz Lira da Silva ◽  
Ana Kamila Rodrigues Alves ◽  
Marlilia Moura Coelho Sousa ◽  
...  

Introduction: Alzheimer’s disease (AD) is closely related to diabetes mellitus (DM), and AD is also considered to be type 3 diabetes (T3D). Glycogen synthase kinase-3β (GSK-3β) may be the potential link between DM and AD. GSK-3β is one of the main factors that lead to insulin deficiency and insulin resistance, and insulin resistance is a characteristic of the development of DM. In AD, GSK-3β plays an important role in hyperphosphorylation of the tau protein (tau) associated with microtubules, which is one of the pathological features in AD. Objective: To analyze DM as a factor for the development of AD. METHODOLOGY: This is an integrative review of the literature, which is a construction of a comprehensive analysis of the literature with pre-defined steps, carried out through PubMed, 1.501 articles were found, of which 10 were selected, through the simultaneous crossing between the descriptors “Diabetes mellitus”, “Alzheimer “. Articles written in Portuguese and English published between 2016 and 2021 were inserted. Results: DM associated with insulin resistance affects psychomotor efficiency, attention, learning memory, mental flexibility, speed and executive function of the brain, thus being an independent risk factor for cognitive impairment and damage to the central nervous system, hyperglycemia, which can cause increased oxidative stress leading to progressive functional and structural abnormalities in the brain. Conclusion:The risk of dementia in patients with DM is higher than in nondiabetic patients and it is also well known that DM2 / insulin resistance is involved in AD.


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