Tartary buckwheat improves cognition and memory function in an in vivo amyloid-β-induced Alzheimer model

Abnormal amyloid-β (Aβ) accumulation is the most significant feature of Alzheimer’s disease (AD). Among the several secretases involved in the generation of Aβ, β-secretase (BACE1) is the first rate-limiting enzyme in Aβ production that can be utilized to prevent the development of Aβ-related pathologies. Cinnamon extract, used in traditional medicine, was shown to inhibit the aggregation of tau protein and Aβ aggregation. However, the effect of trans-cinnamaldehyde (TCA), the main component of cinnamon, on Aβ deposition is unknown. Five-month-old 5XFAD mice were treated with TCA for eight weeks. Seven-month-old 5XFAD mice were evaluated for cognitive and spatial memory function. Brain samples collected at the conclusion of the treatment were assessed by immunofluorescence and biochemical analyses. Additional in vivo experiments were conducted to elucidate the mechanisms underlying the effect of TCA in the role of Aβ deposition. TCA treatment led to improvements in cognitive impairment and reduced Aβ deposition in the brains of 5XFAD mice. Interestingly, the levels of BACE1 were decreased, whereas the mRNA and protein levels of three well-known regulators of BACE1, silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α (PGC1α), and PPARγ, were increased in TCA-treated 5XFAD mice. TCA led to an improvement in AD pathology by reducing BACE1 levels through the activation of the SIRT1-PGC1α-PPARγ pathway, suggesting that TCA might be a useful therapeutic approach in AD.

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Insights into amyloid disease from fly models

Essays in Biochemistry ◽

10.1042/bse0560069 ◽

2014 ◽

Vol 56 ◽

pp. 69-83 ◽

Cited By ~ 1

Author(s):

Ko-Fan Chen ◽

Damian C. Crowther

Keyword(s):

Drosophila Melanogaster ◽

Neurodegenerative Disorders ◽

Amyloid Β ◽

Amyloid Β Peptide ◽

Disease Pathogenesis ◽

Amyloid Aggregates ◽

Aβ Amyloid ◽

Polypeptide Chains ◽

Amyloid Diseases

The formation of amyloid aggregates is a feature of most, if not all, polypeptide chains. In vivo modelling of this process has been undertaken in the fruitfly Drosophila melanogaster with remarkable success. Models of both neurological and systemic amyloid diseases have been generated and have informed our understanding of disease pathogenesis in two main ways. First, the toxic amyloid species have been at least partially characterized, for example in the case of the Aβ (amyloid β-peptide) associated with Alzheimer's disease. Secondly, the genetic underpinning of model disease-linked phenotypes has been characterized for a number of neurodegenerative disorders. The current challenge is to integrate our understanding of disease-linked processes in the fly with our growing knowledge of human disease, for the benefit of patients.

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Folate and vitamin B-12 deficiencies additively impaired memory function and disturbed the gut microbiota in amyloid-β infused rats

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000624 ◽

2019 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Sunmin Park ◽

Sunna Kang ◽

Da Sol Kim

Keyword(s):

Insulin Resistance ◽

Gut Microbiota ◽

Insulin Signaling ◽

Gut Microbiome ◽

Metabolic Diseases ◽

Memory Function ◽

Amyloid Β ◽

Impaired Memory ◽

Ca1 Region ◽

Folate And Vitamin B12

Abstract. Folate and vitamin B12(V-B12) deficiencies are associated with metabolic diseases that may impair memory function. We hypothesized that folate and V-B12 may differently alter mild cognitive impairment, glucose metabolism, and inflammation by modulating the gut microbiome in rats with Alzheimer’s disease (AD)-like dementia. The hypothesis was examined in hippocampal amyloid-β infused rats, and its mechanism was explored. Rats that received an amyloid-β(25–35) infusion into the CA1 region of the hippocampus were fed either control(2.5 mg folate plus 25 μg V-B12/kg diet; AD-CON, n = 10), no folate(0 folate plus 25 μg V-B12/kg diet; AD-FA, n = 10), no V-B12(2.5 mg folate plus 0 μg V-B12/kg diet; AD-V-B12, n = 10), or no folate plus no V-B12(0 mg folate plus 0 μg V-B12/kg diet; AD-FAB12, n = 10) in high-fat diets for 8 weeks. AD-FA and AD-VB12 exacerbated bone mineral loss in the lumbar spine and femur whereas AD-FA lowered lean body mass in the hip compared to AD-CON(P < 0.05). Only AD-FAB12 exacerbated memory impairment by 1.3 and 1.4 folds, respectively, as measured by passive avoidance and water maze tests, compared to AD-CON(P < 0.01). Hippocampal insulin signaling and neuroinflammation were attenuated in AD-CON compared to Non-AD-CON. AD-FAB12 impaired the signaling (pAkt→pGSK-3β) and serum TNF-α and IL-1β levels the most among all groups. AD-CON decreased glucose tolerance by increasing insulin resistance compared to Non-AD-CON. AD-VB12 and AD-FAB12 increased insulin resistance by 1.2 and 1.3 folds, respectively, compared to the AD-CON. AD-CON and Non-AD-CON had a separate communities of gut microbiota. The relative counts of Bacteroidia were lower and those of Clostridia were higher in AD-CON than Non-AD-CON. AD-FA, but not V-B12, separated the gut microbiome community compared to AD-CON and AD-VB12(P = 0.009). In conclusion, folate and B-12 deficiencies impaired memory function by impairing hippocampal insulin signaling and gut microbiota in AD rats.

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Inhibition of Amyloid β Aggregation Using Optimized Nano-Encapsulated Formulations of Plant Extracts with High Metal Chelator Activities

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666191210125851 ◽

2020 ◽

Vol 21 (8) ◽

pp. 681-701

Author(s):

Fatma Kazdal ◽

Fatemeh Bahadori ◽

Burak Celik ◽

Abdulselam Ertas ◽

Gulacti Topcu

Keyword(s):

Plant Extracts ◽

Amyloid Β ◽

Toxic Metal ◽

In Vivo Studies ◽

Total Phenolic ◽

Metal Chelator ◽

Apo E ◽

High Metal ◽

Induced Aggregation

Background: The role of Fe+2, Cu+2 and Zn+2 in facilitating aggregation of Amyloid β (Aβ) and consequently, the progression of Alzheimer's disease (AD) is well established. Objective: Development of non-toxic metal chelators is an emerging era in the treatment of AD, in which complete success has not been fully achieved. The purpose of this study was to determine plant extracts with high metal chelator and to encapsulate them in nano-micellar systems with the ability to pass through the Blood Brain Barrier (BBB). Method: Extracts of 36 different Anatolian plants were prepared, total phenolic and flavonoid contents were determined, and the extracts with high content were examined for their Fe+2, Cu+2 and Zn+2 chelating activities. Apolipoprotein E4 (Apo E) decorated nano-formulations of active extracts were prepared using Poly (Lactide-co-Glycolide) (PLGA) (final product ApoEPLGA) to provide BBB penetrating property. Results: Verbascum flavidum aqueous extract was found as the most active sample, incubation of which, with Aβ before and after metal-induced aggregation, resulted in successful inhibition of aggregate formation, while re-solubilization of pre-formed aggregates was not effectively achieved. The same results were obtained using ApoEPLGA. Conclusion: An optimized metal chelator nano-formulation with BBB penetrating ability was prepared and presented for further in-vivo studies.

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The CSF p-tau181/Aβ42 Ratio Offers a Good Accuracy “In Vivo” in the Differential Diagnosis of Alzheimer’s Dementia

Current Alzheimer Research ◽

10.2174/1567205016666190725150836 ◽

2019 ◽

Vol 16 (7) ◽

pp. 587-595 ◽

Cited By ~ 7

Author(s):

Roberto Santangelo ◽

Alessandro Dell'Edera ◽

Arianna Sala ◽

Giordano Cecchetti ◽

Federico Masserini ◽

...

Keyword(s):

Clinical Practice ◽

Clinical Diagnosis ◽

Fdg Pet ◽

Amyloid Β ◽

Cost Effective ◽

Daily Clinical Practice ◽

Different Types ◽

Experimental Trials ◽

Csf Findings

Background: The incoming disease-modifying therapies against Alzheimer’s disease (AD) require reliable diagnostic markers to correctly enroll patients all over the world. CSF AD biomarkers, namely amyloid-β 42 (Aβ42), total tau (t-tau), and tau phosphorylated at threonine 181 (p-tau181), showed good diagnostic accuracy in detecting AD pathology, but their real usefulness in daily clinical practice is still a matter of debate. Therefore, further validation in complex clinical settings, that is patients with different types of dementia, is needed to uphold their future worldwide adoption. Methods: We measured CSF AD biomarkers’ concentrations in a sample of 526 patients with a clinical diagnosis of dementia (277 with AD and 249 with Other Type of Dementia, OTD). Brain FDG-PET was also considered in a subsample of 54 patients with a mismatch between the clinical diagnosis and the CSF findings. Results: A p-tau181/Aβ42 ratio higher than 0.13 showed the best diagnostic performance in differentiating AD from OTD (86% accuracy index, 74% sensitivity, 81% specificity). In cases with a mismatch between clinical diagnosis and CSF findings, brain FDG-PET partially agreed with the p-tau181/Aβ42 ratio, thus determining an increase in CSF accuracy. Conclusions: The p-tau181/Aβ42 ratio alone might reliably detect AD pathology in heterogeneous samples of patients suffering from different types of dementia. It might constitute a simple, cost-effective and reproducible in vivo proxy of AD suitable to be adopted worldwide not only in daily clinical practice but also in future experimental trials, to avoid the enrolment of misdiagnosed AD patients.

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Phenolic Acids Exert Anticholinesterase and Cognition-Improving Effects

Current Alzheimer Research ◽

10.2174/1567205014666171128102557 ◽

2018 ◽

Vol 15 (6) ◽

pp. 531-543 ◽

Cited By ~ 4

Author(s):

Dominik Szwajgier ◽

Ewa Baranowska-Wojcik ◽

Kamila Borowiec

Keyword(s):

Phenolic Acids ◽

Ex Vivo ◽

Amyloid Β ◽

Inhibitory Effect ◽

In Vivo Studies ◽

Amyloid Β Peptide ◽

Beneficial Effects ◽

Aβ Fibrils

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimer's disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.

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Berberine nanoencapsulation attenuates hallmarks of scoplomine induced Alzheimer's-like disease in rats

Current Clinical Pharmacology ◽

10.2174/1574884715666200628112844 ◽

2020 ◽

Vol 15 ◽

Author(s):

Samar R. Saleh ◽

Mariam M. Abady ◽

Mohammed Nofal ◽

Nashwa W. Yassa ◽

Mohamed S. Abdel-latif ◽

...

Keyword(s):

Oxidative Stress ◽

Histopathological Examination ◽

Memory Function ◽

Amyloid Β ◽

Active Pharmaceutical Ingredient ◽

Isoquinoline Alkaloid ◽

Drug Uptake ◽

Male Rats ◽

Morris Water Maze Test ◽

Neuroprotective Effects

Background: Berberine (BBR), an isoquinoline alkaloid, acts as a multipotent active pharmaceutical ingredient to counteract several types of dementia based on its numerous pharmacological actions including antioxidant, antiinflammatory, cholesterol-lowering effect, and inhibition of Aβ production and AChE. However, BBR suffers from poor absorption, bioavailability and brain drug uptake. The present study is directed for the formulation and characterization of Chitosan BBR-nanoparticles (BBR-NPs) as well as the estimation of its neuroprotective effects against scopolamine induced cognitive impairments. Methods: BBR-NPs were formulated using ionic gelation method and tripolyphosphate was chosen as a cross linker. Nanoparticles size, zeta potential, encapsulation efficiency and releasing profile were estimated. To investigate the neuroprotective effects, adult fifty six Wistar male rats were randomly distributed into: three control groups, received saline, polyethylene glycol or chitosan- NPs respectively; induced group, received scopolamine (2 mg/ kg, i.p.) and three treated groups were orally administrated BBR (50 mg/ kg), BBR- NP (7 mg/ kg) and donepezil (2.25 mg/ kg, as positive control) followed by scopolamine injection after 40 min, daily for 4 weeks. Morris water maze test, oxidative stress parameters, cholinergic and amyloid-β processing intermediates as well as neuroplasticity markers and histopathological examination were assessed. Results: Our results showed that BBR- NPs were better than BBR and donepezil as BBR- NPs were powerful inhibitory ligands toward AChE and Aβ42 formation and significantly down regulated Tau, iNOS and BACE gene expression in rats’ hippocampus. BBR-NPs administration, at 1/6 of BBR therapeutic recommended dose, significantly improved learning and memory function. This could be accredited to the diminution of oxidative stress and amyloid-β toxicity in addition to the improvement of the neuroplasticity markers. Conclusions: The enhancing effect of BBR- NPs could be related to the enhancing of its bioavailability, absorption and brain drug uptake which need more investigation in future work.

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Mice with cleavage-resistant N-cadherin exhibit synapse anomaly in the hippocampus and outperformance in spatial learning tasks

Molecular Brain ◽

10.1186/s13041-021-00738-1 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

M. Asada-Utsugi ◽

K. Uemura ◽

M. Kubota ◽

Y. Noda ◽

Y. Tashiro ◽

...

Keyword(s):

Memory Function ◽

Three Dimensional ◽

Excitatory Synapses ◽

Missense Mutations ◽

Glutamatergic Synapses ◽

Learning Tasks ◽

Transmission Electron ◽

Nmdar Activation ◽

And Function

AbstractN-cadherin is a homophilic cell adhesion molecule that stabilizes excitatory synapses, by connecting pre- and post-synaptic termini. Upon NMDA receptor (NMDAR) activation by glutamate, membrane-proximal domains of N-cadherin are cleaved serially by a-disintegrin-and-metalloprotease 10 (ADAM10) and then presenilin 1(PS1, catalytic subunit of the γ-secretase complex). To assess the physiological significance of the initial N-cadherin cleavage, we engineer the mouse genome to create a knock-in allele with tandem missense mutations in the mouse N-cadherin/Cadherin-2 gene (Cdh2R714G, I715D, or GD) that confers resistance on proteolysis by ADAM10 (GD mice). GD mice showed a better performance in the radial maze test, with significantly less revisiting errors after intervals of 30 and 300 s than WT, and a tendency for enhanced freezing in fear conditioning. Interestingly, GD mice reveal higher complexity in the tufts of thorny excrescence in the CA3 region of the hippocampus. Fine morphometry with serial section transmission electron microscopy (ssTEM) and three-dimensional (3D) reconstruction reveals significantly higher synaptic density, significantly smaller PSD area, and normal dendritic spine volume in GD mice. This knock-in mouse has provided in vivo evidence that ADAM10-mediated cleavage is a critical step in N-cadherin shedding and degradation and involved in the structure and function of glutamatergic synapses, which affect the memory function.

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