• Title/Summary/Keyword: Amyloid

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The Acetylcholinesterase Inhibitory Activity of the EtOH Extract of Chaenomelis Fructus and its effects on the Metabolism of Amyloid Precursor Protein in Neuroblastoma Cells (모과 에탄올 추출물의 아세틸콜린에스테라제 저해활성과 신경세포에서 아밀로이드 전구단백질의 대사에 미치는 영향)

  • Kim, Ju Eun;Jo, Youn Jeong;Leem, Jae Yoon
    • Korean Journal of Pharmacognosy
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    • v.46 no.4
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    • pp.327-333
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    • 2015
  • Alzheimer's disease (AD) is a progressive neurodegenerative disorder symptomatically characterized by impairment in memory and cognitive abilities. AD is characterized pathologically by the deposition of ${\beta}$-amyloid ($A{\beta}$) peptides of 40-42 residues, which are generated by processing of amyloid precursor protein (APP). $A{\beta}$ has been believed to be neurotoxic and now is also considered to have a role on the mechanism of memory dysfunction. In this study, we tested that EtOH extract of the fruits of Chaenomeles sinensis Koehne (CSE) affects on the processing of APP from the APPswe over-expressing Neuro2a cell line. We found that CSE increased over 2 folds of the $sAPP{\alpha}$ secretion level, a metabolite of ${\alpha}$-secretase. We showed that CSE reduced the secretion level of $A{\beta}42$ and $A{\beta}40$ by down regulation of ${\beta}$-secretase (BACE) without cytotoxicity. Furthermore, we found that CSE inhibited BACE and acetylcholinesterase activity in vitro. We suggest that Chaenomelis Fructus may be an useful source to develop a herbal medicine for AD.

Mitochondrial Complex I Inhibition Accelerates Amyloid Toxicity

  • Joh, Yechan;Choi, Won-Seok
    • Development and Reproduction
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    • v.21 no.4
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    • pp.417-424
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    • 2017
  • Alzheimer's disease (AD) is neurodegenerative disease, characterized by the progressive decline of memory, cognitive functions, and changes in personality. The major pathological features in postmortem brains are neurofibrillary tangles and amyloid beta ($A{\beta}$) deposits. The majority of AD cases are sporadic and age-related. Although AD pathogenesis has not been established, aging and declining mitochondrial function has been associated. Mitochondrial dysfunction has been observed in AD patients' brains and AD mice models, and the mice with a genetic defect in mitochondrial complex I showed enhanced $A{\beta}$ level in vivo. To elucidate the role of mitochondrial complex I in AD, we used SH-SY5Y cells transfected with DNA constructs expressing human amyloid precursor protein (APP) or human Swedish APP mutant (APP-swe). The expression of APP-swe increased the level of $A{\beta}$ protein in comparison with control. When complex I was inhibited by rotenone, the increase of ROS level was remarkably higher in the cells overexpressing APP-swe compared to control. The number of dead cell was significantly increased in APP-swe-expressing cells by complex I inhibition. We suggest that complex I dysfunction accelerate amyloid toxicity and mitochondrial complex I dysfunction in aging may contribute to the pathogenesis of sporadic AD.

Mechanisms of Amyloid-β Peptide Clearance: Potential Therapeutic Targets for Alzheimer's Disease

  • Yoon, Sang-Sun;AhnJo, Sang-Mee
    • Biomolecules & Therapeutics
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    • v.20 no.3
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    • pp.245-255
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    • 2012
  • Amyloid-${\beta}$ peptide ($A{\beta}$) is still best known as a molecule to cause Alzheimer's disease (AD) through accumulation and deposition within the frontal cortex and hippocampus in the brain. Thus, strategies on developing AD drugs have been focused on the reduction of $A{\beta}$ in the brain. Since accumulation of $A{\beta}$ depends on the rate of its synthesis and clearance, the metabolic pathway of $A{\beta}$ in the brain and the whole body should be carefully explored for AD research. Although the synthetic pathway of $A{\beta}$ is equally important, we summarize primarily the clearance pathway in this paper because the former has been extensively reviewed in previous studies. The clearance of $A{\beta}$ from the brain is accomplished by several mechanisms which include non-enzymatic and enzymatic pathways. Nonenzymatic pathway includes interstitial fluid drainage, uptake by microglial phagocytosis, and transport across the blood vessel walls into the circulation. Multiple $A{\beta}$-degrading enzymes (ADE) implicated in the clearance process have been identified, which include neprilysin, insulin-degrading enzyme, matrix metalloproteinase-9, glutamate carboxypeptidase II and others. A series of studies on $A{\beta}$ clearance mechanism provide new insight into the pathogenesis of AD at the molecular level and suggest a new target for the development of novel therapeutics.

Reference value of serum amyloid P : a systematic review (혈청 아밀로이드 P (SAP)의 정상 참고치 탐색을 위한 문헌 고찰)

  • Park, Sunju;Jung, Jeeyoun;Jang, Soobin
    • Journal of Society of Preventive Korean Medicine
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    • v.23 no.2
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    • pp.91-99
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    • 2019
  • Objectives : The aim of this study was to examine the reference value of biomarker serum amyloid p (SAP) to diagnose blood stasis objectively. Methods : Pubmed-Medline, Cochrane library, EMBASE were searched using the key words 'SAP' and 'serum amyloid p' in June 2018. Original articles of human adults that published in English, studies that recruited from the clinical research settings or well defined population based cohorts were only included. Results : A total of 12 studies were selected to extract the reference value of SAP. It was between 8.5 ng/mL (0.0085 mg/L) to 57.5 mg/L. Although the disease varied, most of them showed elevated SAP levels in the disease group (1.1-1.5 times). Conclusions : This study is meaningful in that it summarizes the results of previous researches of SAP, which has the potential to be diagnostic index of blood stasis.

Non-Controlled Clinical Efficacy Study Following Brain Six Complex Extract Administration in Dogs with Cognitive Dysfunction Syndrome

  • Ga-Won Lee;Woong-Bin Ro;Min-Hee Kang;Heyong-Seok Kim;Hee-Myung Park
    • Journal of Veterinary Clinics
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    • v.40 no.6
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    • pp.408-413
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    • 2023
  • The incidence of canine cognitive dysfunction syndrome (CCDS), a prominent geriatric disease, is increasing because of the extended lifespan of companion animals. Various complementary therapies have been proposed for the management of CCDS. This study evaluated the clinical efficacy of the Brain Six Complex Extract in dogs with cognitive dysfunction syndrome (CDS). Fifteen dogs with CDS were included, and four to five drops of Brain Six Complex Extract, composed of herbal extracts, were applied around the dorsal neck of all dogs twice daily for 1-3 months. Clinical efficacy was evaluated using the CCDS scale, and serum β-amyloid oligomer concentrations were measured before and after administration of the extract. The CCDS scale score significantly decreased after administration in dogs with CDS (p = 0.0313), compared to pre-administration levels. Although the serum β-amyloid oligomer concentration decreased after administration, the change was not statistically significant (p > 0.05). A notable decrease was observed between pre- and post-administration in dogs with β-amyloid levels >300 pg/mL (p = 0.0313). The laboratory results showed no remarkable adverse effects of the extract. This study suggests that Brain Six Complex Extract extract could be an adjunctive treatment for dogs with CDS.

Molecular Simulations for Anti-amyloidogenic Effect of Flavonoid Myricetin Exerted against Alzheimer’s β-Amyloid Fibrils Formation

  • Choi, Young-Jin;Kim, Thomas Donghyun;Paik, Seung R.;Jeong, Karp-Joo;Jung, Seun-Ho
    • Bulletin of the Korean Chemical Society
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    • v.29 no.8
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    • pp.1505-1509
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    • 2008
  • Comparative molecular simulations were performed to establish molecular interaction and inhibitory effect of flavonoid myricetin on formation of amyloid fibris. For computational comparison, the conformational stability of myricetin with amyloid $\beta$ -peptide (A$\beta$ ) and $\beta$ -amyloid fibrils (fA$\beta$) were traced with multiple molecular dynamics simulations (MD) using the CHARMM program from Monte Carlo docked structures. Simulations showed that the inhibition by myricetin involves binding of the flavonoid to fA$\beta$ rather than A$\beta$ . Even in MD simulations over 5 ns at 300 K, myricetin/fA$\beta$ complex remained stable in compact conformation for multiple trajectories. In contrast, myricetin/A$\beta$ complex mostly turned into the dissociated conformation during the MD simulations at 300 K. These multiple MD simulations provide a theoretical basis for the higher inhibitory effect of myricetin on fibrillogenesis of fA$\beta$ relative to A$\beta$ . Significant binding between myricetin and fA$\beta$ observed from the computational simulations clearly reflects the previous experimental results in which only fA$\beta$ had bound to the myricetin molecules.

β-Sitosterol treatment attenuates cognitive deficits and prevents amyloid plaque deposition in amyloid protein precursor/presenilin 1 mice

  • Ye, Jian-Ya;Li, Li;Hao, Qing-Mao;Qin, Yong;Ma, Chang-Sheng
    • The Korean Journal of Physiology and Pharmacology
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    • v.24 no.1
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    • pp.39-46
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    • 2020
  • Alzheimer's disease (AD) is the most common neurodegenerative disorder causing dementia worldwide, and is mainly characterized by aggregated β-amyloid (Aβ). Increasing evidence has shown that plant extracts have the potential to delay AD development. The plant sterol β-Sitosterol has a potential role in inhibiting the production of platelet Aβ, suggesting that it may be useful for AD prevention. In the present study, we aimed to investigate the effect and mechanism of β-Sitosterol on deficits in learning and memory in amyloid protein precursor/presenilin 1 (APP/PS1) double transgenic mice. APP/PS1 mice were treated with β-Sitosterol for four weeks, from the age of seven months. Brain Aβ metabolism was evaluated using ELISA and Western blotting. We found that β-Sitosterol treatment can improve spatial learning and recognition memory ability, and reduce plaque load in APP/PS1 mice. β-Sitosterol treatment helped reverse dendritic spine loss in APP/PS1 mice and reversed the decreased hippocampal neuron miniature excitatory postsynaptic current frequency. Our research helps to explain and support the neuroprotective effect of β-Sitosterol, which may offer a novel pharmaceutical agent for the treatment of AD. Taken together, these findings suggest that β-Sitosterol ameliorates memory and learning impairment in APP/PS1 mice and possibly decreases Aβ deposition.

Chongmyung-tang Inhibits the Cytotoxicity of Beta-amyloid in Neuro 2A Neuroblastoma Cells (베타 아밀로이드 유도성 Neuro 2A 세포독성에 대한 총명탕의 효과)

  • Gug Yun Jai;Choi Hyuk;Kim Tae Heon;Kang Hyung Won;Lyu Young Su
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.5
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    • pp.1418-1425
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    • 2004
  • The water extract of Chongmyung-tang has been traditionally used for treatment of memory-disorder in oriental medicine. This study was designed to investigate the protective mechanisms of Chongmyung-tang on β-amyloid or H₂O₂-induced cytotoxicity in Neuro 2A cells. The water extract of Chongmyung-tang significantly reduced both β-amyloid or H₂O₂-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, it inhibited the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition(MPT) and the modulation in expression of Bcl-2 family proteins in H₂O₂-treated H9c2 cells. Furthermore, pretreatment of quercetin inhibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 were completely abolished in H₂O₂-treated cells. Taken together, that data suggest that the protective effects of the water extract of Chongmyung-tang against β-amyloid induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

Usefulness of 18F-Florbetaben in Alzheimer's Disease Diagnosis (알츠하이머병 진단에서 18F-Florbetaben의 유용성)

  • Lee, Hyo-Yeong;Im, In-Chul;Song, Min-jae;Shin, Seong-gyu
    • Journal of the Korean Society of Radiology
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    • v.10 no.5
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    • pp.307-312
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    • 2016
  • Alzheimer's disease is the most common degenerative brain diseases that causes dementia. ${\beta}$-amyloid neuritic plaque density that accumulates in the brain is difficult to perform daily living, such as memory loss, language ability deterioration. It is used to estimate ${\beta}$-amyloid neuritic plaque density in adult patients with cognitive impairment who are being evaluated for Alzheimer's disease and other causes of cognitive impairment. Using the $^{18}F$-Florbetaben with high sensitivity and specificity for the ${\beta}$-amyloid neuritic plaque density to evaluate the usefulness for the early diagnosis of Alzheimer's disease. In $^{18}F$-FDG Brain imaging shows no specific findings. And it appeared on the MR-Brain imaging without atrophy of the hippocampus. However, the intake of ${\beta}$-amyloid neuritic plaque density in $^{18}F$-Florbetaben informs that it is the progress of Alzheimer's disease. Therefore, $^{18}F$-Florobetaben is very useful for early diagnosis of Alzheimer's disease.

Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer's disease

  • Yan, Ji-Jing;Ahn, Won-Gyun;Jung, Jun-Sub;Kim, Hee-Sung;Hasan, Md. Ashraful;Song, Dong-Keun
    • Nutrition Research and Practice
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    • v.8 no.4
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    • pp.386-390
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    • 2014
  • BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer's disease (AD); intracerebroventricular injection of ${\beta}$-amyloid peptide ($A{\beta}$) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of $A{\beta}1$-42 until evaluation) effectively blocked $A{\beta}1$-42-induced impairment in passive avoidance performance, and $A{\beta}1$-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-$1{\alpha}$ in the hippocampus. In addition, it alleviated the $A{\beta}1$-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-$1{\beta}$ in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.