• Biomolecules & Therapeutics
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• v.22 no.3
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• pp.232-238
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• 2014

Alzheimer's disease (AD) is the most common neurodegenerative disease without known ways to cure. A key neuropathologic manifestation of the disease is extracellular deposition of beta-amyloid peptide (Ab). Specific mechanisms underlying the development of the disease have not yet been fully understood. In this study, we investigated effects of 4-O-methylhonokiol on memory dysfunction in APP/PS1 double transgenic mice. 4-O-methylhonokiol (1 mg/kg for 3 month) significantly reduced deficit in learning and memory of the transgenic mice, as determined by the Morris water maze test and step-through passive avoidance test. Our biochemical analysis suggested that 4-O-methylhonokiol ameliorated $A{\beta}$ accumulation in the cortex and hippocampus via reduction in beta-site APP-cleaving enzyme 1 expression. In addition, 4-O-methylhonokiol attenuated lipid peroxidation and elevated glutathione peroxidase activity in the double transgenic mice brains. Thus, suppressive effects of 4-O-methylhonokiol on $A{\beta}$ generation and oxidative stress in the brains of transgenic mice may be responsible for the enhancement in cognitive function. These results suggest that the natural compound has potential to intervene memory deficit and progressive neurodegeneration in AD patients.

• Journal of Oriental Neuropsychiatry
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• v.21 no.2
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• pp.191-200
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• 2010

Objectives : This experiment was designed to investigate the effect of Chongmyung-Tang Prescription Combination(CmTP-$C_{1-10}$) extract on the production of amyloid $\beta$ protein and $\beta$-site amyloid precursor protein-cleaving enzyme(BACE) activity. Methods : The effect of CmTP-$C_{1-10}$ extract on expression of APP mRNA, BACE2 mRNA in BV2 microglia cell line treated by lipopolysacchride(LPS) and amyloid $\beta$ protein fragment(A$\beta$ fragment) were investigated. The effect of CmTP-$C_{1-10}$ extract on production of amyloid $\beta$ protein(A$\beta$) in BV2 microglia cell line treated by LPS and A$\beta$ fragment were investigated. The effect of CmTP-$C_{1-10}$ extract on BACE activity were investigated. Results : 1. CmTP-$C_9$ extract the most significantly suppressed the expression of APP mRNA, BACE2 mRNA in BV2 microglia cell line treated by LPS and A$\beta$ fragment. 2. CmTP-$C_9$ extract significantly suppressed the production of A$\beta$ in BV2 microglia cell line treated by LPS and A$\beta$ fragment. 3. CmTP-$C_9$ extract the most significantly inhibited BACE activity. Conclusions : These results suggest that CmTP-$C_9$ may be effective for the prevention and treatment of Alzheimer's Disease. Investigation into clinical use of CmTP-$C_9$ for Alzheimer's Disease is suggested for future research.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.1
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• pp.91-95
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• 2010

Alzheimer's disease (AD) is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}$-amyloid (A${\beta}$) peptides. It is urgent to develop effective therapies for the treatment of AD, since our society rapidly accelerate aging. A${\beta}$ peptides have been believed to be neurotoxic and now are also considered to have affects on the mechanism of memory formation, which are generated by processing of amyloid precursor protein (APP). In this study, effects of Styrax Liquides (SL) on the metabolism of APP were analyzed. SL inhibited the secretion of A${\beta}$ from the Neuro2a cell line (APPswe cell) expressing a mutation of APPswe. Immunoblotting study showed that it inhibited ${\beta}$-site APP cleaving enzyme (BACE) from the APPswe cells. We suggest that SL inhibits APP metabolism and A${\beta}$ generation by the means of BACE inhibitory mechanism. This is the first report that SL inhibits the secretion of A${\beta}$ peptides from neuroblastoma cells.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.3
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• pp.189-195
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• 2013

Amyloid-${\beta}$ peptide ($A{\beta}$), generated by proteolytic cleavage of the amyloid precursor protein (APP), plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). The key step in the generation of $A{\beta}$ is cleavage of APP by beta-site APP-cleaving enzyme 1 (BACE1). Levels of BACE1 are increased in vulnerable regions of the AD brain, but the underlying mechanism is unknown. In the present study, we reported the effects of ferrous ions at subtoxic concentrations on the mRNA levels of BACE1 and a-disintegrin-and-metalloproteinase 10 (ADAM10) in PC12 cells and the cell responses to ferrous ions. The cell survival in PC12 cells significantly decreased with 0 to 0.3 mM $FeCl_2$, with 0.6 mM $FeCl_2$ treatment resulting in significant reductions by about 75%. 4,6-diamidino-2-phenylindole (DAPI) staining showed that the nuclei appeared fragmented in 0.2 and 0.3 mM $FeCl_2$. APP-${\alpha}$-carboxyl terminal fragment (APP-${\alpha}$-CTF) associations with ADAM10 and APP-${\beta}$-CTF with BACE1 were increased. Levels of ADAM10 and BACE1 mRNA increased in response to the concentrations of 0.25 mM, respectively. In addition, p-ERK and p-Bad (S112, S155) expressions were increased, suggesting that APP-CTF formation is related to ADAM10/ BACE1 expression. Levels of Bcl-2 protein were increased, but significant changes were not observed in the expression of Bax. These data suggest that ion-induced enhanced expression of AMDA10/BACE1 could be one of the causes for APP-${\alpha}/{\beta}$-CTF activation.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.529-534
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• 2010

Alzheimer's disease (AD) is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}$-amyloid ($A{\beta}$) peptides, which are generated by processing of amyloid precursor protein (APP). It is urgent to develop effective therapies for the treatment of AD, since our society rapidly accelerate aging. $A{\beta}$ peptides have been believed to be neurotoxic and now are also considered to have effects on the mechanism of memory formation. Recently, we investigated that a quinoline compound from natural product reduced the secretion of $A{\beta}$ from the neuroblastoma N2a cells (NL/N cell line) overexpressing APPswe. In this study, 3-phenyl-1-isoquinolinamine, a synthetic isoquinoline compound was analyzed to determine its effects on the metabolism of APP. It inhibited the secretion of $A{\beta}$ peptides from the N2a NL/N cell line. Beta-site APP cleaving enzyme (BACE) fluorescence resonance energy transfer (FRET) assay revealed that it inhibited BACE activity in a dose dependent manner. Immunoblotting study showed that it inhibited APP stabilization and expression and it slightly increased the stablization and the expression of ${\gamma}$-secreatase component from the N2a NL/N cell line. We suggest that 3-phenyl-1-isoquinolinamine inhibits APP metabolism and $A{\beta}$ generation by the means of BACE inhibitory mechanism. This is the first report that 3-phenyl-1-isoquinolinamine inhibits the secretion of $A{\beta}$ peptides from neuroblastoma cells.

• Journal of the Korean Chemical Society
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• v.58 no.6
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• pp.553-559
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• 2014

Alzheimer's disease (AD) is a devastating neurodegenerative disease that represents the most common form of dementia among the elderly population. The deposition of aggregated ${\beta}$-amyloid ($A{\beta}$) senile plaques in the human brain is a classic observation in the neuropathology of AD, yet an understanding of the mechanism of their formation remains elusive. $A{\beta}$ is formed through endoproteolysis of the amyloid precursor protein (APP) by ${\beta}$-secretase (BACE1, ${\beta}$-site APP-cleaving enzyme) and ${\gamma}$-secretase. In this study, BACE1 protein was successfully over-expressed, purified, and refolded and utilized in a binding study with hispidin. We developed a simpler refolding method using a urea gradient and size-exclusion gel filtration to purify an active BACE1 protein variant, in larger quantities than that reported previously, and measured the binding affinity of hispidin to the BACE1 protein variant through isothermal titration calorimetry.

• YAKHAK HOEJI
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• v.51 no.4
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• pp.264-269
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• 2007

Alzheimer’s disease (AD) is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}-amyloid $ (A ${\beta}$) peptides, which are generated by processing of amyloid precursor protein (APP). It is urgent to develop effective therapies for the treatment of AD, since our society rapidly accelerate aging. A${\beta}$ peptides have been believed to be neurotoxic and now are also considered to have effects on the mechanism of memory formation. In this study, effects of radicicol on the metabolism of APP were analyzed. Radicicol inhibited the secretion of A${\beta}$ from the Neuro2a cell line (APPswe cell) expressing APPswe. Beta-site APP cleaving enzyme (BACE) fluorescence resonance energy transfer (FRET) assay revealed that it inhibited BACE activity in a dose dependently manner. Immunoblotting study showed that it inhibited intracellular heat shock protein (HSP)90 and it increased the secretion of HSP90 from the APPswe cells. We suggest that radicicol inhibits APP metabolism and Ap generation by the means of HSP90 inhibitory mechanism and partially BACE inhibitory mechanism. This is the first report that radicicol inhibits the secretion of A${\beta}$ peptides from neuroblastoma cells.

• YAKHAK HOEJI
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• v.49 no.2
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• pp.168-173
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• 2005

Alzheimers disease (AD) is the most prevalent form of neurodegenerations associated with aging in the human population. This disease is characterized by the extracellular deposition of beta-amyloid (A ${\beta}$) peptide in cerebral plaques. The A ${\beta}$ peptide is derived from the ${\beta}$-amyloid precursor protein ( ${\beta}$APP). Photolytic processing of ${\beta}$APP by ${\beta}$-secretase(beta-site APP-cleaving enzyme, BASE) and ${\gamma}$-secretase generates the A ${\beta}$ peptide. Several lines of evidence support that A ${\beta}$-induced neuronal cell death is major mechanisms of development of AD. Accordingly, the ${\beta}$-and ${\gamma}$-secretase have been implicated to be excellent targets for the treatment of AD. We previously found that sesaminol glucosides have improving effect on memory functions through anti-oxidative mechanism. In this study, to elucidate possible other mechanism (inhibition of ${\beta}$-and ${\gamma}$-secretase) of sesaminol glucosides, we examined the improving effect of sesaminol glucosides in the scopolamine (1 mg/kg/mouse)-induced memory dysfunction using water maze test in the mice. Sesaminol glucosides (3.75, 7.5 mg/kg/6ml/day p.o., for 3 weeks) reversed the latency time, distance and velocity by scopolamine in dose dependent manner. Next, ${\beta}$-and ${\gamma}$-secretase activities were determined in different regions of brain. Sesaminol glucosides dose-dependently attenuated scopolamine-induced ${\beta}$-secretase activities in cortex and hippocampous and ${\gamma}$-secretase in cortex. This study therefore suggests that sesaminol glucosides may be a useful agent for prevention of the development or progression of AD, and its inhibitory effect on secretase may play a role in the improving action of sesaminol glucosides on memory function.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.332-339
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• 2012

The components of Magnolia officinalis have well known to act anti-inflammatory, anti-oxidative and neuroprotective activities. These efficacies have been sold many products as nutritional supplement extracted from bark of Magnolia officinalis. Thus, to assess and compare neuroprotective effect in the nutritional supplement (Magnolia $Extract^{TM}$, Health Freedom Nutrition LLC, USA) and our ethanol extract of Magnolia officinalis (BioLand LTD, Korea), we investigated memorial improving and anti-Alzheimer's disease effects of extract products of Magnolia officinalis in a transgenic AD mice model. Oral pretreatment of two extract products of Magnolia officinalis (10 mg/kg/day in 0.05% ethanol) into drinking water for 3 months ameliorated memorial dysfunction and prevented $A{\beta}$ accumulation in the brain of Tg2576 mice. In addition, extract products of Magnolia officinalis also decreased expression of ${\beta}$-site APP cleaving enzyme 1 (BACE1), amyloid precursor protein (APP) and its product, C99. Although both two extract products of Magnolia officinalis could show preventive effect of memorial dysfunction and $A{\beta}$ accumulation, our ethanol extract of Magnolia officinalis (BioLand LTD, Korea) could be more effective than Magnolia $Extract^{TM}$ (Health Freedom Nutrition LLC, USA). Therefore, our results showed that extract products of Magnolia officinalis were effective for prevention and treatment of AD through memorial improving and anti-amyloidogenic effects via down-regulating ${\beta}$-secretase activity, and neuroprotective efficacy of Magnolia extracts could be differed by cultivating area and manufacturing methods.