• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.299-307
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• 2021

뇌 내 amyloid beta (Aβ) 축적으로 인한 신경독성은 산화적 스트레스를 야기하여 알츠하이머 질환(Alzheimer's disease, AD)을 유도하는 것으로 알려져 있다. 본 연구는 여주(Momordica charantia L.)의 활성분획물인 butanol (BuOH) 분획물의 Aβ_25-35 유도 AD 동물모델에서 인지능 개선 효과에 대해 연구하였다. T-미로 실험 및 물체인지실험을 통해서 여주 BuOH 분획물 100 및 200 mg/kg/day 농도 투여군은 AD를 유도한 control군에 비해 유의적으로 새로운 경로와 물체를 탐색하는 비율이 감소되어 공간인지 및 물체인지능력 개선 효과를 확인하였다. 수중미로실험을 통해 학습·기억력에 미치는 효과를 측정한 결과, 여주 BuOH 분획물 투여군은 훈련을 반복할수록 숨겨진 도피대를 찾아가는 시간이 감소함을 통해 학습·기억력 개선 효과를 나타내었다. 여주 BuOH 분획물이 산화적 스트레스 개선 효과에 미치는 효과를 확인하기 위해 뇌, 간, 신장 조직에서 지질과 산화 함량 및 nitric oxideNO 생성량을 측정하였다. 여주 BuOH 분획물을 처리한 군은 Aβ_25-35를 주입한 control군에 비해 유의적으로 뇌, 간, 신장 조직에서 지질과산화 함량 및 NO 생성량이 감소되어 산화적 스트레스 개선 효과를 확인하였다. 따라서 본 연구는 여주 BuOH 분획물이 Aβ_25-35 유도 AD 동물모델에서 산화적 스트레스 개선을 통해 인지능력 개선 효과를 나타냄을 확인하였으며, 이에 따라 여주는 AD 예방 및 개선용 소재로써의 가능성이 있는 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.273-279
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• 2009

The accumulation of ${\beta}$-amyloid (A${\beta}$) aggregates is a characteristic of Alzheimer's disease (AD). Furthermore, these aggregates have neurotoxic effects on cells, and thus, molecules that inhibit A${\beta}$ aggregate formation could be valuable therapeutics for AD. It is well known that aggregation of A${\beta}$ depends on its hydrophobicity, and thus, in order to increase the hydrophilicity of A${\beta}$, we considered using citrate, an anionic surfactant with three carboxylic acid groups. We hypothesized that citrate could reduce hydrophobicity and increase hydrophilicity of A${\beta}_{1-40}$ molecules via hydrophilic/electrostatic interactions. We found that citrate significantly inhibited A${\beta}_{1-40}$ aggregation and significantly protected SH-SY5Y cell line against A${\beta}_{1-40}$ aggregates-induced neurotoxicity. In details, we examined the effects of citrate on A${\beta}_{1-40}$ aggregation and on A${\beta}_{1-40}$ aggregates-induced cytotoxicity, cell viability, and apoptosis. Th-T assays showed that citrate significantly inhibited A${\beta}_{1-40}$ aggregation in a concentration-dependent manner (Th-T intensity: from 91.3% in 0.01 mM citrate to 82.1% in 1.0 mM citrate vs. 100.0% in A${\beta}_{1-40}$ alone). In cytotoxicity and viability assays, citrate reduced the toxicity of A${\beta}_{1-40}$ in a concentration-dependent manner, in which the cytotoxicity decreased from 107.5 to 102.3% as compared with A${\beta}_{1-40}$ aggregates alone treated cells (127.3%) and the cell viability increased from 84.6 to 93.8% as compared with the A${\beta}_{1-40}$ aggregates alone treated cells (65.3%). Furthermore, Hoechst 33342 staining showed that citrate (1.0 mM) suppressed A${\beta}_{1-40}$ aggregates-induced apoptosis in the cells. This study suggests that citrate can inhibit A${\beta}_{1-40}$ aggregation and protect neurons from the apoptotic effects of A${\beta}_{1-40}$ aggregates. Accordingly, our findings suggest that citrate administration should be viewed as a novel neuroprotective strategy for AD.

• Journal of Ginseng Research
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• 제40권3호
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• pp.278-284
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• 2016

Background: The ginsenoside Rb1 (Rb1) is the most abundant compound in the root of Panax ginseng. Recent studies have shown that Rb1 has a neuroprotective effect. However, the mechanisms underlying this effect are still unknown. Methods: We used stable isotope labeling with amino acids in cell culture, combined with quantitative mass spectrometry, to explore a potential protective mechanism of Rb1 in ${\beta}$-amyloid-treated neuronal cells. Results: A total of 1,231 proteins were commonly identified from three replicate experiments. Among these, 40 proteins were significantly changed in response to Rb1 pretreatment in ${\beta}$-amyloid-treated neuronal cells. Analysis of the functional enrichments and protein interactions of altered proteins revealed that actin cytoskeleton proteins might be linked to the regulatory mechanisms of Rb1. The CAP1, CAPZB, TOMM40, and DSTN proteins showed potential as molecular target proteins for the functional contribution of Rb1 in Alzheimer's disease (AD). Conclusion: Our proteomic data may provide new insights into the protective mechanisms of Rb1 in AD.

• 혜화의학회지
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• 제8권1호
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• pp.793-825
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• 1999

For the development of drugs for alzheimer,s disease, the study was done to review the oriental pathology, clinical data, recent trends for research and strategy for future study. The results were as follows: 1. The medical term Chi-dsi implying alzheimer,s disease was referred for the first time in a medical book, Hwatasheneubijeon written by Hwa-Ta and its differentiation and treatment were studied more in Ming or Ching dynasties. Chi-dai can be differentated as weak(虛) syndrome and Shi(實) syndrome. This can be caused by deficiencies of renal Yin, renal Yang, cardiac Yin and hepatic blood, while that by deficiencies of pathological fluid(痰飮) and clotted blood(瘀血). 2. Dementia can be roughly classified as alzheimer's disease and multi-infarct disease. Its causes were known to be cholinergic transmitter, C-peptide, amyloid-${\beta}$, apolipoprotein, APP(amyloid precursor protein), TGF, MMP-9 and free radical. 3. In Korea experimental studies were chiefly done for the elimataion of C-peptide, amyloid-${\beta}$, apolipoprotein, APP for alzheimer's disease, for the development of drug inhibiting degerative change following CVA and loss of memory and also administrative measure was done by support of government. 4. Drugs of dimentia developed so far were Chi-Dai dan, extracts from aloe, mushroom, green tea, Ganoderma and also folic acid, vitamin C, DHEA and silk amino acid were reported to be effective in dimenta. 5. Future strategic research had better be done on dementia-inducing factors such as acetylcholine, C-peptide, amyloid-${\beta}$, apolipoprotein, APP, TGF, MMP-9 and free radical, development of animal model for dimentia, clinical study, epidemiology, nursing and administrative studies and also consortium for dimentia research should be formed so that repeated investment be avoided.

• 농업과학연구
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• 제49권2호
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• pp.227-237
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• 2022

Amyloid beta (Aβ) is produced from an amyloid precursor protein by the activation of the amyloidogenic pathway, and it is widely known to cause Alzheimer's disease (AD). In this study, we investigated the neuroprotective effects of three flavonoids, quercitrin, isoquercitrin, and afzelin, from Acer okamotoanum against Aβ-induced neurotoxicity in SH-SY5Y neuronal cells. Aβ_25-35 treatments resulted in decreased cell viability and increased levels of nuclei condensation and fragmentation. However, an isoquercitrin treatment dose-dependently increased cell viability and decreased nuclei condensation and fragmentation levels. SH-SY5Y cells treated with Aβ_25-35 showed increased reactive oxygen species (ROS) production compared to that from cells not treated with Aβ_25-35. However, treatment with the three flavonoids significantly inhibited ROS production compared to an Aβ_25-35-treated control group, indicating that the three flavonoids blocked neuronal oxidative stress. For a closer examination of the neuroprotective mechanisms, we measured the expressions of the non-amyloidogenic pathway-related proteins of a disintegrin and metalloprotease 10 (ADAM10) and the tumor necrosis factor-α converting enzyme (TACE). An isoquercitrin treatment enhanced the expressions of ADAM10 compared to the control group. In addition, the three flavonoids activated the non-amyloidogenic pathway via the upregulation of TACE. In conclusion, we demonstrated neuroprotective effects of three flavonoids from A. okamotoanum, in particular isoquercitrin, on neurotoxicity by the regulation of the non-amyloidogenic pathway in Aβ_25-35-treated SH-SY5Y cells. Therefore, we suggest that flavonoids from A. okamotoanum may have some potential as therapeutics of AD.

• 대한한의학회지
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• 제27권2호
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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.

• 대한화학회지
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• 제58권6호
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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.

• Journal of Korean Neurosurgical Society
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• 제39권6호
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• pp.447-450
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• 2006

Cerebral amyloid angiopathy[CAA] is characterized by the deposition of amyloid ${\beta}-protein$ in the walls of small to medium-sized arteries of the leptomeninges and cerebral cortex. While often asymptomatic, CAA can develop into intracerebral hemorrhage facilitated by arterial hypertension. We report the case of a 52-year-old man with CAA and arterial hypertension who developed recurrent cerebral hemorrhages on three different occasions and in multiple non-overlapping loci over a period of nine years. Based on our findings, we recommend brain biopsies for all patients undergoing evacuation of multiple recurrence or atypical pattern intracerebral hemorrhages.

• Toxicological Research
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• 제17권
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• pp.47-57
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• 2001

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, and its pathology is characterized by the presence of numerous numbers of senile plaques and neurofibrillary tangles. Several genetic and transgenic studies have indicated that excess amount of $\beta$-amyloid protein (A$\beta$) is produced by mutations of $\beta$TEX>$\beta$-amyloid precursor protein and causes learning impairment. Moreover, $A\beta$ has a toxic effect on cultured nerve cells. To prepare AD model animals, we have examined continuous (2 weeks) infusion of $A\beta$ into the cerebral ventricle of rats. Continuous infusion of $A\beta$ induces learning impairment in water maze and passive avoidance tasks, and decreases choline acetyltransferase activity in the frontal cortex and hippocampus. Immunohistochemical analysis revealed diffuse depositions of $A\beta$ in the cerebral cortex and hippocampus around the ventricle. Furthermore, the nicotine-evoked release of acetylcholine and dopamine in the frontal cortex/hippocampus and striatum, respectively, is decreased in the $A\beta$-infused group. Perfusion of nicotine (50 $\mu\textrm{M}$) reduced the amplitude of electrically evoked population spikes in the CA1 pyramidal cells of the control group, but not in those of the $A\beta$-infused group, suggesting the impairment of nicotinic signaling in the $A\beta$-infused group. In fact, Kd, but not Bmax, values for ［$^3H$］ cytisine binding in the hippocampus significantly increased in the $A\beta$-infused rats. suggesting the decrease in affinity of nicotinic acetylcholine receptors. Long-term potentiation (LTP) induced by tetanic stimulations in CA1 pyramidal cells, which is thought to be an essential mechanism underlying learning and memory, was readily observed in the control group, whereas it was impaired in the $A\beta$-infused group. Taken together, these results suggest that $A\beta$ infusion impairs the signal transduction mechanisms via nicotinic acetylcholine receptors. This dysfunction may be responsible, at least in part, for the impairment of LTP induction and may lead to learning and memory impairment. We also found the reduction of glutathione- and Mn-superoxide dismutase-like immunoreactivity in the brains of $A\beta$-infused rats. Administration of antioxidants or nootropics alleviated learning and memory impairment induced by $A\beta$ infusion. We believe that investigation of currently available transgenic and non-transgenic animal models for AD will help to clarify the pathogenic mechanisms and allow assessment of new therapeutic strategies.

• 대한한의학회지
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• 제29권2호
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• pp.151-164
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• 2008

Objective: To investigate the effects of Yeongdamsagantang (YDGT) on apoptosis of neuronal cells that can result in dementia. Method: The water extract of the YDGT was tested in vitro for its beneficial effects on neuronal survival and neuroprotective functions, particularly in connection with $A{\beta}$ oligomer-related dementias. $A{\beta}$ oligomers derived from proteolytic processing of the ${\beta}-amyloid$ precursor protein (APP), including the $amyloid-{\beta}$ peptide $(A{\beta})$, play a critical role in the pathogenesis of Alzheimer's disease. A neuroblastoma cell line stably expressing an $A{\beta}$ oligomerassociated neuronal degeneration was used to investigate if YDGT inhibits formation of $A{\beta}$ oligomer. To measure the ATP generating level in mitochondrial membrane, luciferin/luciferase luminescence kit (Promega) and luminator was used, and to survey the protein's apparition, confocal microscopy was used. Result: $A{\beta}oligomer$ had a profound attenuation in the increase in CT105 expressing neuro2A cells from YDGT. Experimental evidence indicates that YDGT protected against neuronal damage from cells, but its cellular and molecular mechanisms remain unknown. We demonstrated that YDGT inhibited formation of $amyloid-{\beta}$ $(A{\beta})$ oligomers, which were the behavior, and possibly causative, features of AD. The decreased $A{\beta}$ oligomer in the presence of YDGT was observed in the conditioned medium of this $A{\beta}oligomer-secreting$ cell line under in vitro. In the cells, YDGT significantly attenuated mitochondrion-initiated apoptosis. Conclusion: (i) a direct $A{\beta}$ oligomer toxicity and the apoptosis initiated by the mitochondria; and (ii) multiple cellular and molecular neuroprotective mechanisms, including attenuation of apoptosis and direct inhibition of $A{\beta}$ oligomer aggregation, underlie the neuroprotective effects of YDGT.