• Journal of the Korean neurological association
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• 제36권4호
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• pp.314-317
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• 2018

Focal subarachnoid hemorrhage occasionally presents as transient focal neurologic episodes mimicking transient ischemic attack (TIA). Unless properly diagnosed, it may aggravate cerebral hemorrhage by administering antithrombotic agents. Therefore, clinicians need to be aware that such focal subarachnoid hemorrhage sometimes cannot be detected on noncontrast computed tomography and blood-sensitive magnetic resonance imaging can detect even a small amount of hemorrhage. We describe an 85-year-old woman with focal subarachnoid hemorrhage and possible cerebral amyloid angiopathy who presented transient left arm weakness recurrently, which mimicked TIA.

• Proceedings of the PSK Conference
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.82.2-83
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• 2003

Beta-amyloid peptide (A${\beta}$) is considered to be responsible for the pathogenesis of the Alzheimer's disease. Several lines of evidence support that A${\beta}$-amyloid-induced cytotoxicity is mediated through the generation of reactive oxygen species (ROS). Agents that are able to scavenge excess ROS may be useful as protecting or reducing agents for development or progress of AD. Green tea extract has been known to have antioxidant property. Our previous studies also demonstrate that green tea extract protected ischemia/reperfusion-induced brain injury by reduction of cell death through scavenging of oxidative damages of macromolecules. (omitted)

• Korean Journal of Pharmacognosy
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• 제51권4호
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• pp.238-243
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• 2020

Perilla frutescens Britton var. acuta Kudo, an annual plant primarily cultivated in China, Japan, and Korea, has been used as a traditional medicine to treat inflammatory diseases, depression, and many anxiety-related disorders. Previously, we reported the inhibitory effects of n-hexane layer of P. frutescens var. acuta extract against beta-amyloid (Aβ) aggregation, and the isolation of asarone derivatives as active constituents from n-hexane layer. In this study, dichloromethane layer of P. frutescens var. acuta was applied to bioassay-guided isolation methods accompanied with Thioflavin T (Th T) fluorescence assay to investigate the inhibitory effect on Aβ aggregation and disaggregation. As the results, three triterpenoids including ursolic acid (1), tormentic acid (2) and corosolic acid (3) were isolated. All compounds reduced Aβ aggregation and increased disaggregation of preformed Aβ aggregates in a dose-dependent manner. However, the inhibitory effect of three compounds on Aβ aggregation was not correlated with antioxidant activity, which was measured by DPPH assay. Taken together, these results suggest that the triterpenoid derivatives from P. frutescens have the potential to be developed as good therapeutics or preventatives for AD.

• Biomedical Science Letters
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• 제27권4호
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• pp.208-215
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• 2021

The purpose of this study was to explain the pathology of Alzheimer's disease (AD) and to investigate the correlation between AD and microRNA. AD is the most common type of dementia, accounting for about 80% of all types of dementia, causing dysfunction in various daily activities such as memory loss, cognitive impairment, and behavioral impairment. The typical pathology of AD is explained by the accumulation of beta-amyloid peptide plaques and neurofibrillary tangles containing hyperphosphorylated tau protein. On the other hand, microRNA is small non-coding RNA 22~23 nucleotides in length that binds to the 3' untranslated region of messenger RNA to inhibit gene expression. Many reports explain that microRNAs found in circulating biofluids are abundant in the central nervous system, are involved in the pathogenic mechanism of AD, and act as important factors for early diagnosis and therapeutic agents of AD. Therefore, this paper aims to clarify the correlation between AD and microRNA. In this review, the basic mechanism of miRNAs is described, and the regulation of miRNAs in the pathological processes of AD are highlighted. Furthermore, we suggest that miRNA-based system in development of therapeutic and diagnostic agents of AD can be a promising tool.

• Food Science of Animal Resources
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• 제44권3호
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• pp.607-619
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• 2024

Probiotics are functional microorganisms that exhibit various biological activities, such as allergic reactions, inflammation, and aging. The aim of this study is to evaluate the effects of Bifidobacterium lactis CBT BL3 (BL) on the amyloid beta (Aβ)-mediated cognitive impairments. Oral administration of live BL to intracerebroventricularly Aβ-injected mice significantly attenuated short- and long-term memory loss estimated using the Y-maze and Morris water maze tests. We found that expression of apoptosisrelated proteins such as caspase-9, caspase-3, and cleaved poly (ADP-ribose) polymerase was significantly elevated in the brain tissues of Aβ-injected mouse brains when compared to that of the control mouse group. Interestingly, these expression levels were significantly decreased in the brain tissue of mice fed BL for 6 wk. In addition, the abnormal over-phosphorylation of mitogen-activated protein kinases (MAPKs) such as ERK1/2, p38 MAPK, and JNK in the brain tissue of intracerebroventricularly Aβ-injected mice was significantly attenuated by oral administration of BL. Taken together, the results indicate that Aβ-induced cognitive impairment may be ameliorated by the oral administration of BL by controlling the activation of MAPKs/apoptosis in the brain. This study strongly suggests that BL can be developed as a functional probiotic to attenuate Aβ-mediated cognitive deficits.

• Dementia and Neurocognitive Disorders
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• 제21권4호
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• pp.107-116
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• 2022

Attention is being paid to diagnosis and treatment of mild cognitive impairment (MCI) because early diagnosis and preventive management can slow down the progression of Alzheimer's disease. In particular, in the present era, the use of biomarkers for predicting conversion into dementia is permitted in medical practice. Therefore, authors aimed to propose additional considerations when updating guidelines for the management of MCI, including predictable biomarkers, revising treatment option after additional clinical trials for cholinesterase inhibitors, and detailed regimes for lifestyle interventions. After reviewing 3 patients with MCI by detailed evaluation, we realized that cholinesterase inhibitors were not recommended. In addition, regular exercise and cognitive training were only possible recommendations for patients according to current guidelines, although all 3 patients had evidence of β-amyloid accumulation and related neurodegeneration. Furthermore, caregivers for all 3 patients were worried whether patients could keep doing regular exercise and cognitive training by themselves and asked about the economic training system which monitors patients so that they can keep training. Therefore, we propose that guidelines for managing MCI need to be updated in the present era when the use of biomarkers for predicting conversion into dementia is permitted in medical practice.

• Clinical Nutrition Research
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• 제11권3호
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• pp.159-170
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• 2022

Ischemic stroke and Alzheimer's disease (AD) are representative geriatric diseases with a rapidly increasing prevalence worldwide. Recent studies have reported an association between ischemic stroke neuropathology and AD neuropathology. Ischemic stroke shares some similar characteristics with AD, such as glia activation-induced neuroinflammation, amyloid beta accumulation, and neuronal cell loss, as well as some common risk factors with AD progression. Although there are considerable similarities in neuropathology between ischemic stroke and AD, no studies have ever compared specific genetic changes of brain cortex between ischemic stroke and AD. Therefore, in this study, I compared the cerebral cortex transcriptome profile of 5xFAD mice, an AD mouse model, with those of middle cerebral artery occlusion (MCAO) mice, an ischemic stroke mouse model. The data showed that the expression of many genes with important functional implications in MCAO mouse brain cortex were related to synaptic dysfunction and neuronal cell death in 5xFAD mouse model. In addition, changes in various protein-coding RNAs involved in synaptic plasticity, amyloid beta accumulation, neurogenesis, neuronal differentiation, glial activation, inflammation and neurite outgrowth were observed. The findings could serve as an important basis for further studies to elucidate the pathophysiology of AD in patients with ischemic stroke.

• Journal of Life Science
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• 제21권5호
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• pp.647-655
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• 2011

The neurotoxicity of aggregated amyloid ${\beta}$ ($A{\beta}$) has been implicated as a critical cause in the pathogenesis of Alzheimer's disease (AD). It can cause neurotoxicity in AD by evoking a cascade of apoptosis to neuron. Here, we investigated the neuroprotective effects of cilostazol, which acts as a phosphodiesterase III inhibitor, on $A{\beta}_{25-35}$-induced cytotoxicity in mouse neuronal cells and cognitive decline in the C57BL/6J AD mouse model via peroxisome proliferator-activated receptor (PPAR)-${\gamma}$ activation. $A{\beta}_{25-35}$ significantly reduced cell viability and increased the number of apoptotic-like cells. Cilostazol treatment recovered cells from $A{\beta}$-induced cell death as well as rosiglitazone, a PPAR-${\gamma}$ activator. These effects were suppressed by GW9662, an antagonist of PPAR-${\gamma}$ activity, indicative of a PPAR-${\gamma}$-mediated signaling. In addition, cilostazol and rosiglitazone also restored PPAR-${\gamma}$ activity levels that had been altered as a result of $A{\beta}_{25-35}$ treatment, which were antagonized by GW9662. Furthermore, cilostazol also markedly decreased the number of apoptotic-like cells and decreased the Bax/Bcl-2 ratio. Intracerebroventricular injection of $A{\beta}_{25-35}$ in C57BL/6J mice resulted in impaired cognitive function. Oral administration of cilostazol (20 mg/kg) for 2 weeks before $A{\beta}_{25-35}$ injection and once a day for 4 weeks post-surgery almost completely prevented the $A{\beta}_{25-35}$-induced cognitive deficits, as did rosiglitazone. Taken together, our findings suggest that cilostazol could attenuate $A{\beta}_{25-35}$-induced neuronal cell injury and apoptosis as well as promote the survival of neuronal cells, subsequently improving cognitive decline in AD, partly because of PPAR-${\gamma}$ activation. The phosphodiesterase III inhibitor cilostazol may be the basis of a novel strategy for the therapy of AD.

• The Korea Journal of Herbology
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• 제29권6호
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• pp.73-83
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• 2014

Objectives : This study was investigated the effects of the root of Polygala tenuifolia (POL) on learning and memory impairment induced by chronic cerebral hypoperfusion in rats. Methods : Chronic cerebral hypoperfusion was produced by permanent bilateral common carotid artery occlusion (pBCAO). POL was administered orally once a day (130 mg/kg of water-extract) for 28 days starting at 4 weeks after the pBCAO. The acquisition of learning and the retention of memory were tested on 9th week after the pBCAO using the Morris water maze. In addition, effects of POL on $A{\beta}$ generation and expressions of APP and BACE1 were observed in the hippocampus of rats. Results : POL significantly prolonged the swimming time spent in target quadrant and significantly reduced the swimming time spent in the quadrant far from the target. POL significantly increased the percentage of swim in the targer quadrant in the retention test, while POL was not effective on the escape latencies in the acquisition training trials. POL significantly reduced the levels of $A{\beta}_{(1-40)}$ and $A{\beta}_{(1-42)}$ in the cerebral cortex and the level of $A{\beta}_{(1-42)}$ in the hippocampus produced by chronic cerebral hypoperfusion. POL also significantly attenuated the up-regulation of APP and BACE1 expression in the hippocampus produced by chronic cerebral hypoperfusion. Conclusions : The results show that POL alleviated memory deficit and up-regulation of $A{\beta}$ and BACE1 expressions in the hippocampus. This result suggests that POL may exert ameliorating effect on memory deficit through inhibition of ${\beta}$-secretase activity and $A{\beta}$ generation.

• The Journal of Korean Medicine
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• 제35권4호
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• pp.10-23
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• 2014

Objectives: This study evaluated the effects of Guibi-tang (GBT) on neuronal apoptosis and cognitive impairment induced by beta amyloid ($A{\beta}$), (1-42) injection in the hippocampus of ICR mice. Methods: $A{\beta}$ (1-42) was injected unilaterally into the lateral ventricle using a Hamilton syringe and micropump ($2{\mu}g/3{\mu}{\ell}$, $0.6{\mu}{\ell}/min$). Water extract of GBT was administered orally once a day (500 mg/kg) for 3 weeks after the $A{\beta}$ (1-42) injection. Acquisition of learning and retention of memory were tested using the Morris water maze. Neuronal damage and $A{\beta}$ accumulation in the hippocampus was observed using cresyl violet and Congo red staining. The anti-apoptotic effect of GBT was evaluated using TUNEL labeling in the hippocampus. Results: GBT significantly shortened the escape latencies during acquisition training trials. GBT significantly increased the number of target headings to the platform site, the swimming time spent in the target quadrant, and significantly shortened the time for the 1st target heading during the retention test trial. GBT significantly attenuated the reduction in thickness and number of CA1 neurons, and $A{\beta}$ accumulation in the hippocampus produced by $A{\beta}$ (1-42) injection. GBT significantly reduced the number of TUNEL-labeled neurons in the hippocampus. Conclusion: These results suggest that GBT improved cognitive impairment by reducing neuronal apoptosis and $A{\beta}$ accumulation in the hippocampus. GBT may be a beneficial herbal formulation in treating cognitive impairment including Alzheimer's disease.