• Title/Summary/Keyword: amyloid ${\beta}$

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A Mini Review on Aβ Oligomers and its Pathogencity

  • Tuyet, Pham Thi Dieu
    • Journal of Integrative Natural Science
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    • v.7 no.2
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    • pp.79-86
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    • 2014
  • Amyloid oligomers are believed to play important causal roles in many types of amyloid-related degenerative diseases. Many different laboratories have reported amyloid oligomers that differ in size, morphology, toxicity, and method of preparation or purification, raising the question of the structural relationships among these oligomer preparations. The structural plasticity that has been reported to occur in amyloid formed from the same protein sequence indicates that it is quite possible that different oligomer preparations may represent distinct structural variants. In view of the difficulty in determining the precise structure of amyloids, conformation- and epitope-specific antibodies may provide a facile means of classifying amyloid oligomer structures. Conformation-dependent antibodies that recognize generic epitopes that are specifically associated with distinct aggregation states of many different amyloid-forming sequences indicate that there are at least two fundamentally distinct types of amyloid oligomers: fibrillar and prefibrillar oligomers. Classification of amyloid oligomers according to their underlying structures may be a more useful and rational approach than relying on differences in size and morphology.

Gossypin Protects Primary Cultured Rat Cortical Cells from Oxidative Stress- and $\beta$-Amyloid-Induced Toxicity

  • Yoon, Injae;Lee, Kwang-Heun;Choi, Jungsook
    • Archives of Pharmacal Research
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    • v.27 no.4
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    • pp.454-459
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    • 2004
  • The present study investigated the effects of gossypin, 3,3',4',5,7,8-hexahydroxyflavone 8-glucoside, on the toxicity induced by oxidative stress or $\beta$-amyloid ($A_{\beta}$) in primary cultured rat cortical cells. The antioxidant properties of gossypin were also evaluated by cell-free assays. Gossypin was found to inhibit the oxidative neuronal damage induced by xanthinelxanthine oxidase or by a glutathione depleting agent, D,L-buthionine (S,R)-sulfoximine. In addition, gossypin significantly attenuated the neurotoxicity induced by $A_{{\beta}(25-35)}$. Furthermore, gossypin dramatically inhibited lipid peroxidation initiated by $Fe^{2+}$ and ascorbic acid in rat brain homogenates. It also exhibited potent radical scavenging activity generated from 1 ,1-diphenyl-2-picrylhydrazyl. These results indicate that gossypin exerts neuroprotective effects in the cultured cortical cells by inhibiting oxidative stress- and $A_{\beta}$-induced toxicity, and that the antioxidant properties of gossypin may contribute to its neuroprotective actions.

Effects of MeOH Extract of Impatiens balsamina L. on the Metabolism of Amyloid Precursor Protein in Neuroblastoma Cells (봉선화 전초의 메탄올 추출물이 신경세포에서 아밀로이드 전구단백질의 대사에 미치는 영향)

  • Jo, Yoon Jeong;Leem, Jae Yoon
    • Korean Journal of Pharmacognosy
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    • v.46 no.1
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    • pp.72-77
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    • 2015
  • One of the most common forms of dementia, Alzheimer's disease (AD) is a progressive neurodegenerative disorder symptomatically characterized by impairment in memory and cognitive abilities. AD is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}$-amyloid ($A{\beta}$) peptides, 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 MeOH extract of Impatiens balsamina L. (IBM) affects on the processing of APP from the APPswe over-expressing Neuro2a cell line. We found that IBM increased over 2 folds of the $sAPP{\alpha}$ secretion level, a main metabolite of ${\alpha}$-secretase. We shown that IBM reduced the secretion level of $A{\beta}42$ and $A{\beta}40$ without cytotoxicity. BACE (${\beta}$-site APP cleaving enzyme) FRET assay shown that BACE activity was specifically decreased in the presence of IBM. We suggest that Impatiens balsamina L. may be an useful source to develop a herbal medicine of BACE inhibitor for Alzheimer's disease.

Effects of Bombycis corpus on Amyloid-induced Lipid Peroxidation Antioxidative Enzymes and NO Synthesis in Rat Astrocytes (흰쥐의 뇌 astrocyte에서 $amyloid-{\beta}25-35$로 유발된 지질의 과산화와 항산화 효소계 및 NO 생성에 미치는 백강잠의 효과)

  • Kim, Hee-Joon;Jeong, Ji-Cheon;Yoon, Cheol-Ho
    • The Journal of Internal Korean Medicine
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    • v.22 no.3
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    • pp.331-339
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    • 2001
  • 목적 : 본 연구는 식풍해경(熄風解痙), 소산풍열(疏散風熱) 효능이 있는 백강잠이 치매에 미치는 영향을 알아보기 위하여 실험을 행하였다. 방법 : 치매 유발물질인 $amyloid{\beta}(A{\beta})$ 25-35를 흰쥐의 뇌 astrocyte에 처리한 후 대표적인 항산화 효소인 catalase, superoxide dismutase,glutathione peroxidase 및 glutathione-S-transferase의 활성 변화와 NO 생성 변화를 관찰하였다. 결과 $A{\beta}$ 25-35 처리로 catalase와 superoxide dismutase 활성이 현저히 감소하였으나 백강잠을 처리한 경우는 이들 효소 활성이 크게 증가하였다. 그리고, $A{\beta}$ 25-35의 농도에 의존적으로 증가된 NO 생성은 백강잠의 농도에 의존적으로 유의성 있게 억제되는 것으로 나타났다. 결론 : 백강잠은 항산화계 효소의 활성화 및 $A{\beta}$처리와 같은 치매유발 물질의 독성에 대한 적응능력 향상을 통하여 astrocyte를 보호하는 효능을 가지는 것으로 사료되며, 아울러 노인성 치매 등 임상적 응용에 그 효과가 기대된다.

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Interdigitated Microelectrode Lab-on-a-chip sensing system for Biomoelcule Detection (마이크로패턴된 전극을 이용한 실시간 생체물질 감지 랩칩 시스템)

  • Yoo, Yong Kyoung;Hwang, Kyo Seon;Lee, Jeong Hoon
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1223-1224
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    • 2015
  • Recently, Alzheimer's Disease (AD) is one of the biggest threats to healthy society. Current medical AD diagnosis depends on interviews and the molecular neuroimaging. There is no cure for the disease, which worsens as it progresses, and eventually leads to death. Amyloid ${\beta}$ and Tau-meditated neuronal injury and dysfunction are candidates of biomarker for AD diagnosis using blood. For highly sensitive and selective biosensor platform, interdigitated microelectrodes (IMEs) sensor was prepared with micro fabrication process and Amyloid ${\beta}$ antibody. Amyloid ${\beta}$ concentration of 1, 10, 100, and 1000 pg/mL was injected in reaction chamber with IME sensors, impedance and conductance of IMEs changed respectively. These results show our newly proposed IMEs sensor can be usefully utilized for AD early diagnosis.

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Synthesis of 5-Chloro-3-[4-(3-diethylaminopropoxy)benzoyl]-2(4-methoxyphenyl)benzofuran as a $\beta-Amyloid$ Aggregation

  • Choi, Hong-Dae;Seo, Pil-Ja;Son, Byeong-Wha;Kang, Byoung-Won
    • Archives of Pharmacal Research
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    • v.26 no.12
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    • pp.985-989
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    • 2003
  • An efficient synthesis of 5-chloro-3-[4-(3-diethylaminopropoxy)benzoyl]-2-(4-methoxyphenyl)benzofuran (8), a potent $\beta$-amyloid aggregation inhibitor, is described. 5-Chloro-2-(4-methoxyphenyl)benzofuran (3) was obtained by the one-pot synthesis of 4-chlorophenol with $\omega$(methylsulfinyl)-p-methoxyacetophenone (1) under Pummerer reaction conditions, and it was followed by the desulfurization of the resultant 5-chloro-3-methylthio-2-(4-methoxyphenyl)benzofuran (2e). Acylation of benzofuran 3 with 4-(3-bromopropoxy)benzoyl chloride (6) gave the ketone 7, which was converted into compound 8 by the treatment of diethylamine.

REGULATION OF BETA-AMYLOID-STIMULATED PRO INFLAMMATORY RESPONSES VIA MITOGEN ACTIVATED PROTEIN KINASES AND REDOX SENSITIVE TRANSCRIPTION FACTORS

  • Hee, Jang-Jung;Joon, Surh-Young
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.11b
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    • pp.191-191
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    • 2002
  • Inflammatory as well as oxidative tissue damage has been associated with pathophysiology of Alzheimer's disease (AD), and nonsteroidal anti-inflammatory drugs have been shown to retard the progress of AD. In this study, we have investigated the molecular mechanisms underlying oxidative and inflammatory cell death induced by beta-amyloid (Abeta), a neurotoxic peptide associated with senile plaques formed in the brains of patients with AD, in cultured PC12 cells.(omitted)

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Synthesis of 2-(4-Hydroxyphenyl)benzofurans and Their Application to $\beta$-Amyloid Aggregation Inhibitor

  • Choi, Hong-Dae;Seo, Pil-Ja;Son, Byeng-Wha;Kang, Byoung-Won
    • Archives of Pharmacal Research
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    • v.27 no.1
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    • pp.19-24
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    • 2004
  • The facile synthesis of a series of 2-(4-hydroxyphenyl)benzofurans (4a-e) is described. The one-pot reaction of 4-substituted phenols with the chloride 1 in the presence of zinc chloride afforded 3-methylthio-2-(4-acetoxyphenyl)benzofurans (2a-e). The compounds 4a-e were obtained from the hydrolysis of 2a-e followed by the desulfurization of the resulting 3-methylthio-2-(4-hydroxyphenyl)benzofurans (3a-e). 5-Methyl-3-p-toluoyl-2 -[4-(3-diethylaminopropoxy)phenyl]benzofuran (7), a $\beta$-amyloid aggregation inhibitor, was synthesized by three steps starting from 4a.

Antioxidant and Anti-amyloid Activities of Fermented Kalopanax pictus (엄나무 발효물의 항산화 및 항아밀로이드 활성)

  • Kang, Jung Hoon
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.2
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    • pp.389-398
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    • 2018
  • This study was to investigate the antioxidant and anti-amyloid activities of the extract (KP-HE) from Kalopanax pictus (KP) fermented with Hericium erinaceum (HE) mycelium. Antioxidant activity was evaluated based on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical(ABTS) scavenging assays. In all assays, the extracts from KP, HE and KP-HE had the potential for antioxidant activities. However, antioxidant activity of KP-HE significantly scavenged DPPH radical as compared to the KP and HE. The result suggested that the antioxidant component was increased in the process of KP fermented with HE. KP-HE was shown to significantly inhibite peroxyl radical-mediated DNA strand breakage whereas KP and HE did not inhibit DNA strand breakage. The aggregation of the amyloid-${\beta}$ ($A{\beta}$) peptide is involved in the pathological process of Alzheimer's disease(AD). In this study, the effects of KP, HE and KP-HE on the aggregation of $A{\beta}_{1-42}$ were investigated. KP and HE had little effect on $A{\beta}$ aggregation and KP-HE effectively inhibited $A{\beta}$ aggregation. KP-HE effectively inhibited $A{\beta}$ induced cell death and significantly increased of the 20.3% cell survival at $300{\mu}g/mL$ concentration. KP-HE also decreased intracellular reactive oxygen specie levels in $A{\beta}$-treated cells. The results suggested that KP-HE had antioxidant and anti-amyloid activities. Therefore, KP-HE could potentially be used as a valuable functional food ingredient to prevent neurodegenerative disorders such as AD.

The Effects of Antioxidant and Anti-Alzheimer on Hydrogen peroxide and $\beta$-amyloid peptid-induced PC 12 cells by Semen Ziziphi Spinosae water extract ($H_{2}O_2$와 A$\beta$로 유도된 pc12 cell에서 생산조인(生酸棗仁) 수추출물의 항산화 및 항치매 효과)

  • Lee, Sang-Won;Kim, Dae-Hyun;Yun, Jong-Hyun;Kim, Jin-Woo;Jung, Ejun-Young;Lee, Seoung-Geun;Lee, Key-Sang;Kim, Tae-Heon;Lyu, Yeoung-Su;Kang, Hyung-Won
    • Journal of Oriental Neuropsychiatry
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    • v.19 no.3
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    • pp.179-193
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    • 2008
  • Objective: The antioxidant and anti-Alzheimer effects of Semen Ziziphi Spinosae (SZS) water extract against the amyloid beta peptide (1-42) or H202-induced oxidative damage and cell death were investigated in rat pheochromocytoma line PC 12. Methods: The cells were incubated with SZS water extract and oxidative damage-inducing materials, amyloid beta peptide (1-42) or H2O2 for 24 h. The cellular viability was assessed by WST-1 assay, cytotoxic damage by LDH activity assay, oxidative damages of cells by fluorescence spectrophotometric method, and apoptosis by TUNEL staining assay. Results and Conclusions: 1. Preincubation of the cells with SZS water extract prior to amyloid beta peptide (1-42) (2 uM) or H2O2 (30 uM) exposure elevated the cell survival close to the control and decreased the level of LDH activity and the fluorescence from the cell homogenates and TUNEL staining of the cells, compared to only amyloid beta peptide (1-42) (2 uM) or H2O2 (30 uM) treated conditions. 2. Our study suggests that Semen Ziziphi Spinosae (SZS) water extract has protective effects against amyloid beta peptide (1-42) or H2O2-induced cell toxicity through the antioxidation mechanism, which might be beneficial for the treatment of Alzheimer's disease.

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