• The Korean Journal of Physiology and Pharmacology
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• 제24권1호
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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.

• 생명과학회지
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• 제30권12호
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• pp.1118-1127
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• 2020

알츠하이머병은 점진적인 신경세포의 손상과 이로 인해 인지기능 장애를 유발하는 질병이다. 이 질환은 현재로서는 치료할 수 있는 질환이 아니고 진행을 멈추게 할 수 있는 방법이 없다. 그러나 초기에 알츠하이머병을 치료하는 것이 가장 효과적이므로 초기 진단은 증상을 관리할 수 있는 가장 좋은 기회를 제공할 수 있다. 알츠하이머병을 진단하기 위한 바이오마커로는 아밀로이드 베타(Aβ), 병적인 타우, 그리고 신경퇴화가 있고, Aβ의 축적, 인산화 타우는 뇌척수액이나 양전자 방출 단층촬영술을 통해 분석할 수 있다. 그러나 뇌척수액의 채취는 매우 침습적이고 양전자 방출 단층촬영술은 전문적인 고가의 장비가 필요하다. 지난 수십년 동안 빠르고 최소한의 침습성을 가진 바이오마커 분석법을 개발하기 위하여 혈액에 기반한 바이오마커 분석 기술이 연구되어 왔다. 그 중 주목할 만 한 발견이 혈장에서 Aβ의 주요 원천으로 혈소판과의 관련성이다. 아밀로이드 베타는 혈액-뇌 장벽을 통과 할 수 있고 정상 상태에서는 뇌와 혈액 간 평형을 이루게 된다. 흥미롭게도, 여러 임상시험 결과 혈장에서 Aβ42/Aβ40 비율이 가벼운 인지장애 질환과 알츠하이머병에서 감소되어 있는 것을 증명하였다. 종합하면, 이러한 최근의 발견들은 침습성을 최소화한 알츠하이머병의 초기 진단 기술을 개발하는 데 이용될 수 있다. 본 총설에서, 저자들은 알츠하이머병의 바이오마커에 대한 최근 연구결과들, 특히 말초에서 Aβ를 생산하는 혈소판의 역할과 혈액 기반 바이오마커로서의 개발 가능성에 대해 고찰하였다.

• EDISON SW 활용 경진대회 논문집
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• 제3회(2014년)
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• pp.237-249
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• 2014

Deposition of amyloid-${\beta}$ ($A{\beta}$) proteins is the conventional pathological hallmark of Alzheimer's disease (AD). The $A{\beta}$ protein formed from the amyloid precursor protein is predominated by the 40 residue protein ($A{\beta}40$) and by the 42 residue protein ($A{\beta}42$). While $A{\beta}40$ and $A{\beta}42$ differ in only two amino acid residues at the C-terminal end, $A{\beta}42$ is much more prone to aggregate and exhibits more neurotoxicity than $A{\beta}40$. Here, we investigate the molecular origin of the difference in the aggregation propensity of these two proteins by performing fully atomistic, explicit-water molecular dynamics simulations. Then, it is followed by the solvation thermodynamic analysis based on the integral-equation theory of liquids. We find that $A{\beta}42$ displays higher tendency to adopt ${\beta}$-sheet conformations than $A{\beta}40$, which would consequently facilitate the conversion to the ${\beta}$-sheet rich fibril structure. Furthermore, the solvation thermodynamic analysis on the simulated protein conformations indicates that $A{\beta}42$ is more hydrophobic than $A{\beta}40$, implying that the surrounding water imparts a larger thermodynamic driving force for the self-assembly of $A{\beta}42$. Taken together, our results provide structural and thermodynamic grounds on why $A{\beta}42$ is more aggregation-prone than $A{\beta}40$ in aqueous environments.

• Nutrition Research and Practice
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• 제15권2호
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• pp.173-186
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• 2021

BACKGROUD/OBJECTIVES: Alzheimer's disease (AD) is the most common cause of dementia in the elderly. Due to the increased incidence of dementia, there is a corresponding increase concerning the importance of AD. In this study, we investigated the protective effects conferred by Zizyphus jujuba (Zj) and Zizyphus jujuba fermented by yeast (Zj-Y), on cognitive impairment in an AD mouse model. MATERIALS/METHODS: AD was induced by injecting amyloid beta25-35 (Aβ25-35) in ICR mice, and subsequently 200 mg/kg Zj or Zj-Y was administered daily for 14 days. The cognitive ability of AD mice was observed through behavioral experiments in T-maze, novel object recognition, and Morris water maze tests. We subsequently measured the levels of malondialdehyde (MDA), nitric oxide (NO), aspartate aminotransferase, and alanine aminotransferase in either tissues or serum. RESULTS: In behavioral tests, deterioration was revealed in the short- and long-term learning and memory functions in the Aβ25-35-injected control group compared to the normal group, indicating that Aβ25-35 injection impairs cognitive functions. However, administration of Zj and Zj-Y improved cognitive function in mice, as compared to the Aβ25-35-injected control mice. In addition, the Aβ25-35 induced elevations of MDA and NO in the brain, kidney, and liver were suppressed after exposure to Zj and Zj-Y. Especially, Zj-Y showed stronger scavenging effect against MDA and NO, as compared to Zj. CONCLUSIONS: Results of the present study indicate that Zj-Y exerts a protective effect on cognitive impairment and memory dysfunction, which is exerted by attenuating the oxidative stress induced by Aβ25-35.

• Nutrition Research and Practice
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• 제17권6호
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• pp.1128-1142
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• 2023

BACKGROUND/OBJECTIVES: Inonotus obliquus has been used as antidiabetic herb around the world, especially in the Russian and Scandinavian countries. Diabetes is widely believed to be a key factor in Alzheimer's disease (AD), which is widely considered to be type III diabetes. To investigate whether I. obliquus can also ameliorate AD, it would be interesting to identify new clues for AD treatment. We tested the anti-AD effects of raw Inonotus obliquus polysaccharide (IOP) in a mouse model of AD (3×Tg-AD transgenic mice). MATERIALS/METHODS: SPF-grade 3×Tg-AD mice were randomly divided into three groups (Control, Metformin, and raw IOP groups, n = 5 per group). β-Amyloid deposition in the brain was analyzed using immunohistochemistry for AD characterization. Gene and protein expression of pertinent factors of the ubiquitin-proteasome system (UPS) was determined using real-time quantitative polymerase chain reaction and Western blotting. RESULTS: Raw IOP significantly reduced the accumulation of amyloid aggregates and facilitated UPS activity, resulting in a significant reduction in AD-related symptoms in an AD mouse model. The presence of raw IOP significantly enhanced the expression of ubiquitin, E1, and Parkin (E3) at both the mRNA and protein levels in the mouse hippocampus. The mRNA level of ubiquitin carboxyl-terminal hydrolase isozyme L1, a key factor involved in UPS activation, also increased by approximately 50%. CONCLUSIONS: Raw IOP could contribute to AD amelioration via the UPS pathway, which could be considered as a new potential strategy for AD treatment, although we could not exclude other mechanisms involved in counteracting AD processing.

• Biomolecules & Therapeutics
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• 제28권1호
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• pp.74-82
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• 2020

Alzheimer's disease (AD) is a progressive and most frequently diagnosed neurodegenerative disorder. However, there is still no drug preventing the progress of this disorder. β-Amyrin, an ingredient of the surface wax of tomato fruit and dandelion coffee, is previously reported to ameliorate memory impairment induced by cholinergic dysfunction. Therefore, we tested whether β-amyrin can prevent AD-like pathology. β-Amyrin blocked amyloid β (Aβ)-induced long-term potentiation (LTP) impairment in the hippocampal slices. Moreover, β-amyrin improved Aβ-induced suppression of phosphatidylinositol-3-kinase (PI3K)/Akt signaling. LY294002, a PI3K inhibitor, blocked the effect of β-amyrin on Aβ-induced LTP impairment. In in vivo experiments, we observed that β-amyrin ameliorated object recognition memory deficit in Aβ-injected AD mice model. Moreover, neurogenesis impairments induced by Aβ was improved by β-amyrin treatment. Taken together, β-amyrin might be a good candidate of treatment or supplement for AD patients.

• Biomolecules & Therapeutics
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• 제19권1호
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• pp.90-96
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• 2011

Automated HPLC/SPE/HPLC coupling experiments using the Sepbox system allowed the rapid identification of four bioactive principles reducing the production of amyloid $\beta$-peptide ($A{\beta}$) from two South African plants, Euclea crispa subsp. crispa and Crinum macowanii. The structures of biologically active compounds isolated from the methanol extract of Euclea crispa subsp. crispa were assigned as 3-oxo-oleanolic acid (1) and natalenone (2) based on their NMR and MS data, while lycorine (3) and hamayne (4) were isolated from the dichloromethane-methanol (1:1) extract of Crinum macowanii. These compounds were shown to inhibit the production of $A{\beta}$ from HeLa cells stably expressing Swedish mutant form of amyloid precursor protein (APPsw).

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.197.2-198
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• 2003

Activation of the apoptosis program by an increased production of beta-amyloid peptides (A${\beta}$) has been implicated in the neuronal cell death of Alzheimer's disease. Bcl-2 is a well demonstrated anti-apoptotic protein, however, the mechanism of anti-apoptotic action of Bcl-2 in A${\beta}$-induced apoptosis of neuronal cells is not fully understood. (omitted)

• Nutrition Research and Practice
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• 제16권2호
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• pp.173-193
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• 2022

BACKGROUND/OBJECTIVES: Alzheimer's disease (AD) is one of the most representative neurodegenerative disease mainly caused by the excessive production of amyloid beta (Aβ). Several studies on the antioxidant activity and protective effects of Populus tomentiglandulosa (PT) against cerebral ischemia-induced neuronal damage have been reported. Based on this background, the present study investigated the protective effects of PT against cognitive impairment in AD. MATERIALS/METHODS: We orally administered PT (50 and 100 mg/kg/day) for 14 days in an Aβ_25-35-induced mouse model and conducted behavioral experiments to test cognitive ability. In addition, we evaluated the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum and measured the production of lipid peroxide, nitric oxide (NO), and reactive oxygen species (ROS) in tissues. RESULTS: PT treatment improved the space perceptive ability in the T-maze test, object cognitive ability in the novel object recognition test, and spatial learning/long-term memory in the Morris water-maze test. Moreover, the levels of AST and ALT were not significantly different among the groups, indicating that PT did not show liver toxicity. Furthermore, administration of PT significantly inhibited the production of lipid peroxide, NO, and ROS in the brain, liver, and kidney, suggesting that PT protected against oxidative stress. CONCLUSIONS: Our study demonstrated that administration of PT improved Aβ_25-35-induced cognitive impairment by regulating oxidative stress. Therefore, we propose that PT could be used as a natural agent for AD improvement.

• The Korean Journal of Physiology and Pharmacology
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• 제21권1호
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• pp.55-64
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• 2017

Progressive memory impairment such as that associated with depression, stroke, and Alzheimer's disease (AD) can interfere with daily life. In particular, AD, which is a progressive neurodegenerative disorder, prominently features a memory and learning impairment that is related to changes in acetylcholine and abnormal ${\beta}$-amyloid ($A{\beta}$) deposition in the brain. In the present study, we investigated the effects of dehydroevodiamine HCl (DHED) on cognitive improvement and the related mechanism in memory-impaired rat models, namely, a scopolamine-induced amnesia model and a $A{\beta}_{1-42}$-infused model. The cognitive effects of DHED were measured using a water maze test and a passive avoidance test in the memory-impaired rat models. The results demonstrate that DHED (10 mg/kg, p.o.) and Donepezil (1 mg/kg, p.o.) ameliorated the spatial memory impairment in the scopolamine-induced amnestic rats. Moreover, DHED significantly improved learning and memory in the $A{\beta}_{1-42}$-infused rat model. Furthermore, the mechanism of these behavioral effects of DHED was investigated using a cell viability assay, reactive oxygen species (ROS) measurement, and intracellular calcium measurement in primary cortical neurons. DHED reduced neurotoxicity and the production of $A{\beta}$-induced ROS in primary cortical neurons. In addition, similar to the effect of MK801, DHED decreased intracellular calcium levels in primary cortical neurons. Our results suggest that DHED has strong protective effects against cognitive impairments through its antioxidant activity and inhibition of neurotoxicity and intracellular calcium. Thus, DHED may be an important therapeutic agent for memory-impaired symptoms.