GINKGETIN AMELIORATES NEUROPATHOLOGICAL CHANGES IN APP/PS1 TRANSGENICAL MICE MODEL

Author(s):  
Y.-Q. Zeng ◽  
Y.-J. Wang ◽  
X.-F. Zhou

The extracellular accumulation of amyloid beta protein (Aβ), reactive gliosis and cerebral amyloid angiopathy (CAA) play critical roles in the pathogenesis of Alzheimer’s disease (AD). Ginkgetin, a biflavone isolated from Ginkgo biloba leaves, was previously reported to exhibit strong neuroprotection against cytotoxic insults induced by oxidative stress and amyloid beta, but it remains unclear whether ginkgetin has therapeutic effect on Alzheimer’s disease (AD) in vivo. In the present study, we investigated 9 months treatment effects of ginkgetin diet in APP/PS1 mice. Our results show that ginkgetin can significantly reduce plasma Aβ levels 59% and Aβ plaque 51% in the brain of APP/PS1 transgenic mice (P<0.05), effectively inhibits cerebral microhemorrhage 69% (P<0.05), significantly decreases astrogliosis 50% and ameliorate inflammation (P<0.05), exhibits several biological properties for AD.

2002 ◽  
Vol 38 ◽  
pp. 37-49 ◽  
Author(s):  
Janelle Nunan ◽  
David H Small

The proteolytic processing of the amyloid-beta protein precursor plays a key role in the development of Alzheimer's disease. Cleavage of the amyloid-beta protein precursor may occur via two pathways, both of which involve the action of proteases called secretases. One pathway, involving beta- and gamma-secretase, liberates amyloid-beta protein, a protein associated with the neurodegeneration seen in Alzheimer's disease. The alternative pathway, involving alpha-secretase, precludes amyloid-beta protein formation. In this review, we describe the progress that has been made in identifying the secretases and their potential as therapeutic targets in the treatment or prevention of Alzheimer's disease.


2020 ◽  
Vol 17 ◽  
Author(s):  
Reem Habib Mohamad Ali Ahmad ◽  
Marc Fakhoury ◽  
Nada Lawand

: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the progressive loss of neurons leading to cognitive and memory decay. The main signs of AD include the irregular extracellular accumulation of amyloidbeta (Aβ) protein in the brain and the hyper-phosphorylation of tau protein inside neurons. Changes in Aβ expression or aggregation are considered key factors in the pathophysiology of sporadic and early-onset AD and correlate with the cognitive decline seen in patients with AD. Despite decades of research, current approaches in the treatment of AD are only symptomatic in nature and are not effective in slowing or reversing the course of the disease. Encouragingly, recent evidence revealed that exposure to electromagnetic fields (EMF) can delay the development of AD and improve memory. This review paper discusses findings from in vitro and in vivo studies that investigate the link between EMF and AD at the cellular and behavioural level, and highlights the potential benefits of EMF as an innovative approach for the treatment of AD.


2008 ◽  
Vol 29 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Li Gan ◽  
Shuhong Qiao ◽  
Xun Lan ◽  
Liying Chi ◽  
Chun Luo ◽  
...  

2018 ◽  
Vol 128 (3) ◽  
pp. 184-192 ◽  
Author(s):  
Maria Dantas Costa Lima Godoy ◽  
Marco Aurélio Fornazieri ◽  
Richard L. Doty ◽  
Fábio de Rezende Pinna ◽  
José Marcelo Farfel ◽  
...  

Objectives: The clinical symptoms of Alzheimer’s disease (AD) are preceded by a long asymptomatic period associated with “silent” deposition of aberrant paired helical filament (PHF)-tau and amyloid-beta proteins in brain tissue. Similar depositions have been reported within the olfactory epithelium (OE), a tissue that can be biopsied in vivo. The degree to which such biopsies are useful in identifying AD is controversial. This postmortem study had 3 main goals: first, to quantify the relative densities of AD-related proteins in 3 regions of the olfactory neuroepithelium, namely, the nasal septum, middle turbinate, and superior turbinate; second, to establish whether such densities are correlated among these epithelial regions as well as with semi-quantitative ratings of general brain cortex pathology; and third, to evaluate correlations between the protein densities and measures of antemortem cognitive function. Methods: Postmortem blocks of olfactory mucosa were obtained from 12 AD cadavers and 24 controls and subjected to amyloid-beta and PHF-tau immunohistochemistry. Results: We observed marked heterogeneity in the presence of the biomarkers of tau and amyloid-beta among the targeted olfactory epithelial regions. No significant difference was observed between the cadavers with AD and the controls regarding the concentration of these proteins in any of these epithelial regions. Only one correlation significant was evident, namely, that between the tau protein densities of the middle and the upper turbinate ( r = .58, P = .002). Conclusion: AD-related biomarker heterogeneity, which has not been previously demonstrated, makes comparisons across studies difficult and throws into question the usefulness of OE amyloid-beta and PHF-tau biopsies in detecting AD.


Author(s):  
Ruiqing Ni ◽  
Zhenyue Chen ◽  
Gloria Shi ◽  
Alessia Villois ◽  
Quanyu Zhou ◽  
...  

AbstractThe abnormal deposition of beta-amyloid proteins in the brain is one of the major histopathological hallmarks of Alzheimer’s disease. Currently available intravital microscopy techniques for high-resolution plaque visualization commonly involve highly invasive procedures and are limited to a small field-of-view within the rodent brain. Here, we report the transcranial detection of amyloid-beta deposits at the whole brain scale with 20 μm resolution in APP/PS1 and arcAβ mouse models of Alzheimer’s disease amyloidosis using a large-field multifocal (LMI) fluorescence microscopy technique. Highly sensitive and specific detection of amyloid-beta deposits at a single plaque level in APP/PS1 and arcAβ mice was facilitated using luminescent conjugated oligothiophene HS-169. Immunohistochemical staining with HS-169, anti-Aβ antibody 6E10, and conformation antibodies OC (fibrillar) of brain tissue sections further showed that HS-169 resolved compact parenchymal and vessel-associated amyloid deposits. The novel imaging platform offers new prospects for in vivo studies into Alzheimer’s disease mechanisms in animal models as well as longitudinal monitoring of therapeutic responses at a single plaque level.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dongdong Zhang ◽  
Zhe Wang ◽  
Chenxia Sheng ◽  
Weijun Peng ◽  
Shan Hui ◽  
...  

Icariin is a prenylated flavonol glycoside derived from the Chinese herbEpimedium sagittatumthat exerts a variety of pharmacological activities and shows promise in the treatment and prevention of Alzheimer’s disease. In this study, we investigated the neuroprotective effects of icariin against amyloid beta protein fragment 25–35 (Aβ25–35) induced neurotoxicity in cultured rat pheochromocytoma PC12 cells and explored potential underlying mechanisms. Our results showed that icariin dose-dependently increased cell viability and decreasedAβ25–35-induced apoptosis, as assessed by MTT assay and Annexin V/propidium iodide staining, respectively. Results of western blot analysis revealed that the selective phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 suppressed icariin-induced Akt phosphorylation, suggesting that the protective effects of icariin are associated with activation of the PI3K/Akt signaling pathway. LY294002 also blocked the icariin-induced downregulation of proapoptotic factors Bax and caspase-3 and upregulation of antiapoptotic factor Bcl-2 inAβ25–35-treated PC12 cells. These findings provide further evidence for the clinical efficacy of icariin in the treatment of Alzheimer’s disease.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Yara Hassaan ◽  
Heba Handoussa ◽  
Ahmed H. El-Khatib ◽  
Michael W. Linscheid ◽  
Nesrine El Sayed ◽  
...  

Epidemiological studies have proven an association between consumption of polyphenols and prevention of Alzheimer’s disease, the most common form of dementia characterized by extracellular deposition of amyloid beta plaques. The aim of this study is pharmacological screening of the aqueous alcohol extract ofMarkhamia platycalyxleaves,Schotia brachypetalaleaves and stalks, and piceatannol compared to aqueous alcohol extract ofCamellia sinensisleaves as potential Alzheimer’s disease drugs. LC-HRESI(-ve)-MSnwas performed to identify phenolics’ profile ofSchotia brachypetalastalks aqueous alcohol extract and revealed ten phenolic compounds as first report: daidzein, naringin, procyanidin isomers, procyanidin dimer gallate, quercetin 3-O-rhamnoside, quercetin 3-O-glucuronide, quercetin hexose gallic acid, quercetin hexose protocatechuic acid, and ellagic acid. Alzheimer’s disease was induced by a single intraperitoneal injection of LPS. Adult male Swiss albino mice were divided into groups of 8–10 mice each receiving treatment for six days.In vivobehavioral tests (Y maze and object recognition) andin vitroestimation of amyloid beta 42 by ELISA showed significant differences between results of treated and nontreated animals.


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