• Journal of Microbiology
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• v.44 no.5
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• pp.502-507
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• 2006

In a previous study, an extract of Clavicorona pyxidata DGUM 29005 mycelia demonstrated an inhibitory effect against enzyme-associated perceptual disorders. We have attempted to determine whether this mycelial extract is also capable of inhibiting the activities of acetylcholinesterase (AChE) and ${\beta}$-secretase (BACE) activity. Butanol, ethanol, and water extracts of C. pyxidata DGUM 29005 mycelia were shown to inhibit AChE activity by 99.3%, 93.7%, and 91.7%, respectively. The inhibitory value of the butanol extract was more profound than that of tacrine (95.4%). The ethanol extract also exerted an inhibitory effect against BACE activity; this fraction may harbor the potential for development into a pharmocotherapeutic modality for the treatment of Alzheimer's disease (AD) patients. Rat pheochromocytoma PC12 cells in culture were not determined to be susceptible to the cytotoxic activity evidenced by the mycelial extract. The ethanol extract inhibited endogenous AChE activity in PC12 cellular homogenates, with an $IC_{50}\;of\;67.5{\mu}g/ml$, after incubation with intact cells, and also inhibited BACE activity in a dose-dependent fashion. These results suggest that the C. pyxidata mycelial extract has the potential to enhance cholinergic function and, therefore, may perform a function in the amelioration of the cholinergic deficit observed in cases of AD, as well as other types of age-associated memory impairment.

• Journal of Life Science
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• v.19 no.5
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• pp.688-691
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• 2009

The methanol extract of muskmelon (Cucumis melo) has been investigated for its cognition enhancing effects by evaluation of inhibitory activities on acetylcholinesterase, a degrading enzyme of acetylcholine, a brain neurotransmitter, and ${\beta}$- secretase, which forms the ${\beta}$-amyloid toxic protein from its precursor protein. A passive avoidance task, one of the animal model experiments for learning and memory, was also performed. As a result, the melon extract showed 15.8% and 35.3% inhibition on acetylcholinesterase and ${\beta}$-secretase, respectively, with a final concentration of 100 mg/ml. In the animal model test, melon extract significantly (p<0.05) lengthened the step-through latency time by 22.7% compared to the control group, suggesting that melon extract has, indeed, an effect on cognition enhancement.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.04a
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• pp.109-120
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• 2006

Alzheimer's disease (AD) is an age-related neurodegenerative disorder. The pathological hallmarks of AD are senile plaques and neurofibrillary tangles in the brain. Major component of senile plaques is amyloid beta peptide(A$\beta$) which is derived from amyloid precursor protein (APP). A$\beta$ is generated through the sequential cleavage of App by $\beta$ - and $\gamma$-secretases. $\beta$-secretase excises the ectodomain of APP ($\beta$-APPs) to leave a 99-amino acid long C-terminal fragment (APP-C99-CTF) in the membrane. $\gamma$-secretase then cleaves this membrane-tethered APP-CTF within the transmembrane domain, so releasing A$\beta$ peptides and APP-intracellular domain (AICD). Thus, $\beta$- and $\gamma$-secretase are regarded to perform the key steps in the pathogenesis of AD and have become important therapeutic targets in the prevention and treatment of AD. Enormous efforts have been focused to develop the amyloid beta related drug for cure of AD becuase A$\beta$ is believed to be one of the major causes of AD. since major pharmaceutical companies in world wide base compete to develop new drug for AD, we have to be careful to choose the drug target to success the tough race. In the present talk, possible drug targets based on basic research results will be discussed. These molecules should be a good target for development of new drug for AD and be less competitive to have a good shape for world wide competition.

• The Journal of Korean Medicine
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• v.27 no.2 s.66
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• pp.122-133
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• 2006

Objectives : The amyloid $\beta$-protein ($A\beta$) is the principal component of the senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors including antioxidants and proteoglycans modify $A{\beta}toxicity$. In this study, we have investigated the protective effects of water- and organic solvent-extracts of Hemerocallis fulva root fractions pre-extracted with methanol on $A\beta$-induced oxidative cell death in cultured rat pheochromocytoma (PC12) cells. Methods : For this study, we used MTT reduction assay for detection of protective effects of water- and organic solvent-extracts of Hemerocallis fulva root fractions pre-extracted with methanol on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used cell-based $\beta$-secretase assay system to investigate the inhibitory effect of water- and organic solvent-extracts of Hemerocallis fulva root on $\beta$-secretase activity. Results : We previously reported that methanol extracts of Hemerocallis fulva root strongly attenuated cytotoxicity induced by the three $A\beta$ fragments ($A{\beta}_{25-35},\;A{\beta}_{1-42}\;A{\beta}_{1-43}$) to both SK-N-MC and PC12 cells. In the present study, we found that butanol-, ethylacetate-, chloroform-, and water-extracts of Hemerocallis fulva root fractions pre-extracted with methanol had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and inhibitory potency to $\beta$-secretase activity. Conclusion : These results suggest that butanol-, ethylacetate-, chloroform-, and water-extracts of Hemerocallis fulva root fractions pre-extracted with methanol may contain the protective component(s) against $A\beta$-induced cell death in PC12 cells as well as inhibitory component(s) to $\beta$-secretase activity.

• Journal of Life Science
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• v.21 no.8
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• pp.1134-1141
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• 2011

Transmembrane protein 21 (TMP21) is a member of the p24 cargo protein family and has been shown to modulate ${\alpha}$-secretase-mediated A${\beta}$ production which was specifically observed in the brains of subjects with Alzheimer's disease (AD). In order to investigate whether TMP21 could affect nerve growth factor (NGF) receptor signaling pathway, the alteration of NGF receptors and their downstream proteins were detected in TMP21 over-expressed cells. CMV/hTMP21 vector used in this study was successfully expressed into TMP21 proteins in B35 cells after lipofectamin transfection. Expressed TMP21 proteins induced the down-regulation of ${\gamma}$-secretase complex components including Presenlin-1 (PS-1), PS-2, Nicastrin (NST), Pen-2 and APH-1. Also, the expression level of NGF receptor $p75^{NTR}$ and RhoA were significantly higher in CMV/hTMP21 transfectants than vehicle transfectants, while their levels returned to vehicle levels after NGF treatment. However, the phosphorylation of NGF receptor TrkA was dramtically decreased in NGF No-treated CMV/hTMP21 transfectants compared with vehicle transfectants, and increased in NGF treated CMV/hTMP21 transfectants. In TrkA downstream signaling pathway, the phosphorylation level of ERK was also decreased in CMV/hTMP21 transfectants, while the phosphorylation of Akt was increased in the same transfectants. Furthermore, NGF treatment induced the increase of phosphorylation level of Akt and ERK in CMV/hTMP21 transfectants. Therefore, these results suggested that over-expression of TMP21may simultaneously induce the up-regulation of $p75^{NTR}$/RhoA expression and the down-regulation of TrkA/ERK phosphorylation through the inhibition of ${\gamma}$-secretase activity.

• Journal of Life Science
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• v.29 no.2
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• pp.173-180
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• 2019

Amyloid ${\beta}$-protein ($A{\beta}$) is the principal component of senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify $A{\beta}$ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used a cell-based ${\beta}$-secretase assay system to investigate the inhibitory effect of the OJEA fraction on ${\beta}$-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by $A{\beta}_{25-35}$ in PC12 cells. The OJEA fraction had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and was strongly inhibitory to ${\beta}$-secretase activity, which resulted in the attenuation of $A{\beta}$ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to $A{\beta}_{25-35}$. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on $A{\beta}$ toxicity.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1371-1376
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• 2006

BACE 1 ($\beta$-secretase), a membrane bound aspartic protease, is a key enzyme in the process of amyloid precursor protein (APP) into A$\beta$ peptide which is considered to play a causative role in Alzheimers Disease (AD). Here, we reported the synthesis and inhibitory activity of optically active 3-amino-4-aryl-piperidines.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.271.2-271.2
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• 2003

The ${\gamma}$- and ${\beta}$-secretase are one of the most important proteases, which cleave amyloid precursor protein (APP) into neurotoxic A${\beta}$ peptide in Azheimer's type dementia. In the course of screening for anti-dementia agents from natural products, the mycelial culture of mushroom Phellinus linteus showed potent inhibition againt ${\beta}$-secretase (BACE1). (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.212.2-212.2
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• 2003

In the course of searching for BACE1 (${\beta}$-secretase) inhibitors from natural products, the ethyl acetate soluble fraction of green tea, which was suspected to be rich in catechin content, showed potent inhibitory activity. (-)-Epigallocatechin gallate, (-)-epicatechin gallate, and (-)-gallocatechin gallate ware isolated with IC$\_$50/ values of 1.6${\times}$10$\^$-6/ M, 4.5${\times}$10$\^$-6/ M, and 1.8${\times}$10$\^$-6/ M, respectively. Seven additional authentic catechins were tested for a fundamental structure-activity relationship. (-)-Catechin gallate, (-)-gallocatechin, and (-)-epigallocatechin significantly inhibited BACE1 activity with IC$\_$50/ values of 6.0${\times}$10$\^$-6/ M, 2.5${\times}$10$\^$-6/ M, and 2.4${\times}$10$\^$-6/ M, respectively. (omitted)

• The Korean Journal of Food And Nutrition
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• v.32 no.6
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• pp.662-668
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• 2019

The purpose of this study was to investigate effect of methanolic extracts of 10 kinds of wild vegetables cultivated in Gangwon province on antioxidant activity, acetylcholinesterase, and β-secretase inhibitory activities. Results showed that among the wild vegetables, Aralia elata(Miq.) Seem shoot extract exhibited the highest total phenol content (84.65±1.08 mg GAE/g) and total flavonoids content (70.77±0.55 mg RE/g), respectively. The antioxidant activity of wild vegetables extracts was measured by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. Aralia elata(Miq.) Seem shoot extracts had the highest DPPH and ABTS scavenging activity (90.16%, 40.18% at 2 mg/mL). As a result, Aralia elata(Miq.) Seem shoot extract was the most effective in terms of acetylcholinesterase inhibitory activity (35.94% at 1 mg/mL). In the β-secretase activity assay, all 10 kinds wild vegetables extracts showed low inhibitory activity, and Aralia elata(Miq.) Seem shoot extract had highest inhibitory activity among the 10 wild vegetables extracts was 14.99%. Taken together, these results showed that Aralia elata(Miq.) Seem shoot extract has potential cognition improvement impact, suggesting that it may provide an effective strategy for improving cognition.