• Journal of Oriental Neuropsychiatry
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• v.12 no.2
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• pp.173-183
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• 2001

Substance P can stimulate secretion of tumor necrosis $factor-\;{\alpha}\;(TNF-\;{\alpha}\;)$ from astrocytes stimulated with lipopolysaccharide (LPS). Here I report that Chilbogeum can modulate cytokines secretion from primary cultures of rat astrocytes. Chilbogeum $(10\;{\mu}g/ml)$ significantly inhibited the $TNF-\;{\alpha}$ secretion by astrocytes stimulated with LPS and Substance P. Interleukin-1 (IL-1) has been shown to elevate $TNF-\;{\alpha}$ secretion from LPS-stimulated astrocytes while having no effect on astrocytes in the absence of LPS. Treatment of Chilbogeum $(10,\;100\;{\mu}g/ml)$ to astrocytes stimulated with both LPS and Substance P decreased IL-1 secretion significantly. The secretion of $TNF-\;{\alpha}$ by LPS and Substance P in astrocytes was progressively inhibited with increasing amount of IL-1 neutralizing antibody. Upon stimulation from various agents, these cells adopt a reactive phenotype, a morphological hallmark in Alzheimer's disease (AD) pathology, during which they themselves may produce still more inflammatory cytokines. Chilbogeum $(10,\;100\;{\mu}g/ml)$ significantly inhibited the $TNF-\;{\alpha}$ secretion by CCF-STTG1 astrocytoma cells stimulated with $A\;{\beta}$ and IL-1. These results suggest that Chilbogeum may inhibit $TNF-\;{\alpha}$ secretion by inhibiting IL-1 secretion and that Chilbogeum has an antiinflammatory activity in AD brain.

• Natural Product Sciences
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• v.21 no.2
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• pp.134-140
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• 2015

The present study aims to investigate the effect of methanol extract of Korean mistletoe (KM; Viscum album var. coloratum), on amyloid $\beta$ protein ($A\beta$) (25-35), a synthetic 25-35 amyloid peptide, -induced neurotoxicity in cultured rat cerebral cortical neurons and memory impairment in mice. Exposure of cultured neurons to $10{\mu}M$ $A\beta$ (25-35) for 24 h induced a neuronal cell death, which was measured by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. KM (10, 30 and $50{\mu}g/ml$) significantly inhibited the $A\beta$ (25-35)-induced apoptotic neuronal death. KM ($50{\mu}g/ml$) inhibited 10 μM Aβ (25-35)-induced elevation of intracellular calcium concentration ([Ca²⁺]_i), which was measured by a fluorescent dye, Fluo-4 AM. Glutamate release into medium and generation of reactive oxygen species (ROS) induced by $10{\mu}M$ $A\beta$ (25-35) were also inhibited by KM (10, 30 and $50{\mu}g/ml$). These results suggest that KM may mitigate the $A\beta$ (25-35)-induced neurotoxicity by interfering with the increase of [Ca²⁺]_i and then inhibiting glutamate release and generation of ROS in cultured neurons. In addition, orally administered KM (25 and 50 mg/kg, 7 days) significantly prevented memory impairment induced by intracerebroventricular injection of $A\beta$ (25-35) (8 nmol). Taken together, it is suggested that anti-dementia effect of KM is due to its neuroprotective effect against $A\beta$ (25-35)-induced neurotoxicity and that KM may have therapeutic role in prevention of the progression of Alzheimer's disease.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.150-161
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• 2007

Acori graminei Rhizomn (AGR) is a perennial herb which has been used clinically as a traditional oriental medicine against stroke, Alzheimer's disease, and vascular dementia. We investigated the effect of AGR on the modulation of gene expression profile in a hypoxic model of cultured rat cortical cells. Rat cerebrocortical cells were grown in Neurobasal medium. On DIV12, cells were treated with AGR $(10ug/m\ell)$, given a hypoxic shock (2% $O_2$, 3 hr) on DIV14, and total RNAs were prepared one day after shock. Microarray analyses indicated that the expression levels of most genes were altered within the global M values +0.5 and -0.5, i.e., 40% increase or decrease. There were 750 genes which were upregulated by < global M +0,2, while 700 genes were downregulated by > global M -0.2. The overall profile of gene expression suggests that AGR suppresses apoptosis (upregulation of anti-apopotic genes such as TEGT, TIEG, Dad, p53, and downregulation of pro-apopotic genes such as DAPK, caspase 2, pdcd8), ROS (upregulation of RARa, AhR), and that AGR has neurotrophic effects (upregulation of Aktl, Akt2). These results provide a platform for investigation of the molecular mechanism of the effect of AGR in neuroprotection.

• Animal cells and systems
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• v.16 no.4
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• pp.302-312
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• 2012

The purpose of this study was to examine whether Phellodendri Cortex extract (PCE) could improve learning and memory impairments caused by lipopolysaccharide (LPS)-induced inflammation in the rat brain. The effect of PCE on modulating pro-inflammatory mediators in the hippocampus and its underlying mechanism were investigated. Injection of LPS into the lateral ventricle caused acute regional inflammation and subsequent deficits in spatial learning ability in the rats. Daily administration of PCE (50, 100, and 200 mg/kg, i.p.) for 21 days markedly improved the LPS-induced learning and memory disabilities in the Morris water maze and passive avoidance test. PCE administration significantly decreased the expression of pro-inflammatory mediators such as tumor necrosis factor-${\alpha}$, interleukin-$1{\beta}$, and cyclooxygenase-2 mRNA in the hippocampus, as assessed by RT-PCR analysis and immunohistochemistry. Together, these findings suggest that PCE significantly attenuated LPS-induced spatial cognitive impairment through inhibiting the expression of pro-inflammatory mediators in the rat brain. These results suggested that PCE may be effective in preventing or slowing the development of neurological disorders, including Alzheimer's disease, by improving cognitive and memory function because of its anti-inflammation activity in the brain.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.799-803
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• 2005

In the course of screening anti-dementia agents from natural products, two $\beta$-secretase (BACE1) inhibitors were isolated from the ethyl acetate soluble fraction of Sanguisorbae Radix by the activity-guided purification using silica gel, Sephadex LH-20, and RP-HPLC. They were identified as 1,2,3-trigalloyl-4,6-hexahydroxydiphenoyl-$\beta$-D-glucopyranoside (Tellimagrandin II, 1) and 1,2,3,4,6-pentagalloyl-$\beta$-D-glucopyranoside (2) and were shown to non-competitively inhibit $\beta$-secretase (BACE1) with the $IC_{50}$ values of $3.10{\times}10^{-6}M\;and\;3.76{\times}10^{-6}M$, respectively. The Ki values of 1 and 2 were $6.84{\times}10^{-6}M\;and\;5.13{\times}10^{-6}M$. They were less inhibitory to asecretase (TACE) and other serine proteases such as chymotrypsin, trypsin, and elastase, suggesting that they were relatively specific inhibitors of BACE1.

• Korean Journal of Medicinal Crop Science
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• v.25 no.5
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• pp.315-321
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• 2017

Background: Glycyrrhiza uralensis Radix (GR) is a crude drugs used in Asian countries that has been reported to prevent the progression of neurodegenerative diseases such as Alzheimer's disease. The present study examined whether GR and its active compounds, glycyrrhizic acid (GA) and isoliquiritigenin (IL), exerted protective effects on $H_2O_2$-induced oxidative damage in C6 glial cells. Methods and Results: We exposed C6 glial cells to hydrogen peroxide ($H_2O_2$) for 24 h and investigated the cellular response to GR and its active compounds by evaluating cell viability, reactivie oxygen species (ROS) production, and apoptosis-related protein expression. GR successfully mitigated the reduced cell viability and ROS production induced by $H_2O_2$ in C6 glial cells, IL and GA significantly increased the cell viability and decreased ROS production. In addition, IL and GA down-regulated apoptotic Baxdependent caspase-3 activation, but each compound exerted different mechanisms, i.e., IL dose-dependently decreased ROS production and, GA up-regulated anti-apoptotic Bcl-2 expression. Conclusions: These results demonstrated that GR and its active components, IL and GA, exhibit potential for use as natural neurodegenerative agents for the modulation of apoptosis in C6 glial cells.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.617-624
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• 2006

Various plant phenolics were assessed for (${\beta}$-secretase (BACE1) inhibitory activity in order to screen for anti-dementia agents. Among 39 phenolics, eight compounds, 1,2,3-trigalloyl glucopyranoside, acetonyl geraniin, euphorscopin, furosine, helioscopinin A, helioscopinin B, jolkinin, and rugosin E exhibited strong inhibition of BACE1 with $IC_{50}$ values of $5.87{\times}10^{-8}-54.93{\times}10^{-6}\;M$. Among them, rugosin E was the most potent ($IC_{50}$ $5.87{\times}10^{-8}\;M$). The active compounds were shown to be non-competitive inhibitors by Dixon plot. All the phenolic BACE1 inhibitors except furosin also suppressed prolyl endopeptidase (PEP) activity. However, these phenolic compounds caused less inhibition of ${\alpha}$-secretase (tumor necrosis factor a converting enzyme; TACE) and no significant inhibition of other serine proteases such as trypsin, chymotrypsin, and elastase was seen, demonstrating that they are relatively specific to both BACE1 and PEP. No significant structure-activity relationships were found.

• Archives of Pharmacal Research
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• v.28 no.12
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• pp.1328-1332
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• 2005

In the course of screening for anti-dementia agents from natural products, two $\beta$-secretase (BACE1) inhibitors were isolated from the husk of pomegranate (Punica granatum) by activity-guided purification. They were identified as ellagic acid and punicalagin with $IC_{50}$ values of 3.9 $\times$$10^{-6}$ and 4.1$\times$$10^{-7}$ M and Ki values of 2.4$\times$$10^{-5}$and 5.9$\times$$10^{-7}$ M, respectively. The compounds were non-competitive inhibitors with a substrate in the Dixon plot. Ellagic acid and punicalagin were less inhibitory to $\alpha$-secretase (TACE) and other serine proteases such as chymotrypsin, trypsin, and elastase, thus indicating that they were relatively specific inhibitors of BACE1.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.966-972
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• 2016

We investigated that methanolic extracts of 20 kinds of seaweeds from Jeju Island for their antioxidant activities, acetylcholinesterase and ${\beta}$-secretase inhibitory activities, and neuronal survival in order to evaluate their potentials as anti-dementia agents. Ecklonia cava extracts had the highest total polyphenol content among the 20 seaweed extracts. The antioxidant activity of seaweed extracts was measured by using 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. It was found that Ecklonia kurome extracts had the highest ABTS scavenging activity ($IC_{50}=0.07{\pm}0.01mg/mL$). As a result, Ecklonia cava, Ecklonia kurome, and Myelophycus simplex extracts were found to be the most effective in terms of acetylcholinesterase inhibitory activity. In the ${\beta}$-secretase activity assay, Ecklonia cava and Ecklonia kurome extracts were effectively inhibited ($84.41{\pm}1.70%$ and $81.17{\pm}2.43%$, respectively). As expected, neuronal cell death induced by $H_2O_2$ in SH-SY5Y cells was diminished by Ecklonia cava, Ecklonia kurome, and Sargassum yezoense extracts. Taken together, these results showed that Ecklonia cava extract has potential anti-dementia activity, which suggests that it might provide an effective strategy for improving dementia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.286-293
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• 2019

Alzheimer's disease (AD) is a neurodegenerative disease caused by accumulation of amyloid beta ($A{\beta}$) in the brain. In the present study, we investigated the neuroprotective effects of four flavonoids such as kaempferol, kaempferol-3-O-glucoside, quercetin, and quercetin-3-${\beta}$-D-glucoside against neuronal apoptosis induced by $A{\beta}$ in SH-SY5Y neuronal cells. Treatment with $A{\beta}$ decreased cell viability compared to the non-treated normal group. However, treatment with the four flavonoids increased cell viability in SH-SY5Y cells treated with $A{\beta}$. In addition, we measured the expression of apoptosis-related proteins such as Bcl-2-associated X protein (Bax) and cleaved caspase-9. Treatment with the four flavonoids down-regulated Bax and cleaved caspase-9 in $A{\beta}$-treated SH-SY5Y neuronal cells. Overall, the results of the present study demonstrated the neuroprotective effect of flavonoids by anti-apoptotic activity in $A{\beta}$-induced SH-SY5Y neuronal cells. These results suggest that these four flavonoids would be useful therapeutic and prevention agents for AD.