• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.237-249
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• 2014

Deposition of amyloid-${\beta}$ ($A{\beta}$) proteins is the conventional pathological hallmark of Alzheimer's disease (AD). The $A{\beta}$ protein formed from the amyloid precursor protein is predominated by the 40 residue protein ($A{\beta}40$) and by the 42 residue protein ($A{\beta}42$). While $A{\beta}40$ and $A{\beta}42$ differ in only two amino acid residues at the C-terminal end, $A{\beta}42$ is much more prone to aggregate and exhibits more neurotoxicity than $A{\beta}40$. Here, we investigate the molecular origin of the difference in the aggregation propensity of these two proteins by performing fully atomistic, explicit-water molecular dynamics simulations. Then, it is followed by the solvation thermodynamic analysis based on the integral-equation theory of liquids. We find that $A{\beta}42$ displays higher tendency to adopt ${\beta}$-sheet conformations than $A{\beta}40$, which would consequently facilitate the conversion to the ${\beta}$-sheet rich fibril structure. Furthermore, the solvation thermodynamic analysis on the simulated protein conformations indicates that $A{\beta}42$ is more hydrophobic than $A{\beta}40$, implying that the surrounding water imparts a larger thermodynamic driving force for the self-assembly of $A{\beta}42$. Taken together, our results provide structural and thermodynamic grounds on why $A{\beta}42$ is more aggregation-prone than $A{\beta}40$ in aqueous environments.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.433-452
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• 2018

This study was conducted to select candidates from plant resources for the purpose of improving or treating Alzheimer's disease, a type of dementia. One hundred and eighty-four plant extracts at a final concentration of $100{\mu}g/ml$ were screened to determine their capacity to inhibit acetylcholinesterase (AChE) by in vitro assay. From this AChE assay, seven plant extracts - including methanol ext. and water ext. of Phellaodendron amurense Rupr. (bark), methanol ext. of Nelumbo nucifera Gaertn (stamen/ovary), methanol ext. of Persicaria tinctoria H. GROSS (flower), methanol ext. of Coptis chinensis (rhizome), ethanol ext. of Cinnamomum cassia Blume(bark) and ethanol ext. of Carthamus tinctorius L. (fruit) - showed effective inhibition activity ranging from 18.7% to 63.1%. The selected extracts were testified their inhibition activities on AChE and BuChE (butyrylcholinesterase) at concentrations of 25, 50, 100, $200{\mu}g/ml$. In the AChE assay, five extracts including methanol ext. of Nelumbo nucifera Gaertn. (stamen/ovary), methanol ext. of Persicaria tinctoria H. GROSS (flower), methanol ext. of Coptis chinensis (rhizome), methanol ext. and water ext. of Phellaodendron amurense Rupr. (bark) showed inhibition activity of 15.0%~73.5%, 19.5%~63.5%, 81.6%~58.5%, 69.9%~80.5%, and 54.8%~78.3%, respectively, at concentrations of 25, 50, 100, $200{\mu}g/ml$. In the BuChE assay, the extracts of Nelumbo nucifera Gaertn. (stamen/ovary), Persicaria tinctoria H. GROSS (flower), and Coptis chinensis (rhizome) showed inhibitory capacities of 58.9~81.6%, 45.8%~72.4%, and 33.1%~55.4% at concentrations of 25, 50, 100, $200{\mu}g/ml$, respectively. In conclusion, it is suggested that Nelumbo nucifera Gaertn. (stamen/ovary), Persicaria tinctoria H. GROSS, Coptis chinensis (rhizome) and Phellaodendron amurense Rupr. (bark) could be selected as candidate materials for improving or treating Alzheimer's disease on the basis of further study.

• Dementia and Neurocognitive Disorders
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• v.17 no.3
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• pp.110-119
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• 2018

Background and Purpose: To analyze $^{18}F-THK5351$ positron emission tomography (PET) scans of patients with clinically diagnosed nonfluent/agrammatic variant primary progressive aphasia (navPPA). Methods: Thirty-one participants, including those with Alzheimer's disease (AD, n=13), navPPA (n=3), and those with normal control (NC, n=15) who completed 3 Tesla magnetic resonance imaging, $^{18}F-THK5351$ PET scans, and detailed neuropsychological tests, were included. Voxel-based and region of interest (ROI)-based analyses were performed to evaluate retention of $^{18}F-THK5351$ in navPPA patients. Results: In ROI-based analysis, patients with navPPA had higher levels of THK retention in the Broca's area, bilateral inferior frontal lobes, bilateral precentral gyri, and bilateral basal ganglia. Patients with navPPA showed higher levels of THK retention in bilateral frontal lobes (mainly left side) compared than NC in voxel-wise analysis. Conclusions: In our study, THK retention in navPPA patients was mainly distributed at the frontal region which was well correlated with functional-radiological distribution of navPPA. Our results suggest that tau PET imaging could be a supportive tool for diagnosis of navPPA in combination with a clinical history.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.81-86
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• 2019

The common hallmark of several neurodegenerative disorders, including Alzheimer's disease (AD), is the presence of chronic neuroinflammation, which contributes to the loss of neuronal structure and function. This study investigated the effects of an ethanolic extract of Sargassum serratifolium (SSE) in a lipopolysaccharides (LPS)-induced murine neuroinflammation model. Mice were administered SSE (100 mg/kg body weight) or vehicle for 5 days by oral gavage, and then treated with LPS or saline by intraperitoneal injection. Thereafter, the brain tissues were collected, and the expression of pro-inflammatory cytokines was analyzed by quantitative real-time RT-PCR. There was a marked increase in the spleen weight index in the LPS-treated groups, which indicated the induction of acute systemic inflammation. Based on significant increases in the levels of IL-1 and IL-6 expression, the induction of neuroinflammation was also evident in the cortex and hippocampus of the LPS-treated groups. The overall expression of IL-1 and IL-6 was decreased slightly by SSE administration, compared with the LPS group, and a marked change in IL-1 was observed in the cortex of the SSE-treated (SSE/LPS) group. These results suggest that SSE has potential as an anti-neuroinflammatory nutraceutical.

• Journal of Ginseng Research
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• v.48 no.1
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• pp.59-67
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• 2024

Background: Alzheimer's disease (AD) has memory impairment associated with aggregation of amyloid plaques and neurofibrillary tangles in the brain. Although anti-amyloid β (Aβ) protein antibody and chemical drugs can be prescribed in the clinic, they show adverse effects or low effectiveness. Therefore, the development of a new drug is necessarily needed. We focused on the cognitive function of Panax ginseng and tried to find active ingredient(s). We isolated panaxcerol D, a kind of glycosyl glyceride, from the non-saponin fraction of P. ginseng extract. Methods: We explored effects of acute or sub-chronic administration of panaxcerol D on cognitive function in scopolamine- or Aβ_25-35 peptide-treated mice measured by several behavioral tests. After behavioral tests, we tried to unveil the underlying mechanism of panaxcerol D on its cognitive function by Western blotting. Results: We found that pananxcerol D reversed short-term, long-term and object recognition memory impairments. The decreased extracellular signal-regulated kinases (ERK) or Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in scopolamine-treated mice was normalized by acute administration of panaxcerol D. Glial fibrillary acidic protein (GFAP), caspase 3, NF-kB p65, synaptophysin and brainderived neurotrophic factor (BDNF) expression levels in Aβ_25-35 peptide-treated mice were modulated by sub-chronic administration of panaxcerol D. Conclusion: Pananxcerol D could improve memory impairments caused by cholinergic blockade or Aβ accumulation through increased phosphorylation level of ERK or its anti-inflammatory effect. Thus, panaxcerol D as one of non-saponin compounds could be used as an active ingredient of P. ginseng for improving cognitive function.

• Journal of Life Science
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• v.29 no.6
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• pp.747-753
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• 2019

Cognitive decline is characterized by reduced long-/short-term memory and attention span, and increased depression and anxiety. Such decline is associated with various degenerative brain disorders, especially Alzheimer's disease (AD) and Parkinson's disease (PD). The increases in elderly populations suffering from cognitive decline create social problems and impose economic burdens, and also pose safety threats; all of these problems have been extensively researched over the past several decades. Possible causes of cognitive decline include metabolic and hormone imbalance, infection, medication abuse, and neuronal changes associated with aging. However, no treatment for cognitive decline is available. In neurodegenerative diseases, changes in the gut microbiota and gut metabolites can alter molecular expression and neurobehavioral symptoms. Changes in the gut microbiota affect memory loss in AD via the downregulation of NMDA receptor expression and increased glutamate levels. Furthermore, the use of probiotics resulted in neurological improvement in an AD model. PD and gut microbiota dysbiosis are linked directly. This interrelationship affected the development of constipation, a secondary symptom in PD. In a PD model, the administration of probiotics prevented neuron death by increasing butyrate levels. Dysfunction of the blood-brain barrier (BBB) has been identified in AD and PD. Increased BBB permeability is also associated with gut microbiota dysbiosis, which led to the destruction of microtubules via systemic inflammation. Notably, metabolites of the gut microbiota may trigger either the development or attenuation of neurodegenerative disease. Here, we discuss the correlation between cognitive decline and the gut microbiota.

• Journal of Oriental Neuropsychiatry
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• v.10 no.1
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• pp.39-51
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• 1999

The effects of Hyangbujapalmultang on the enhancement of learning and memory of AD model rats were studied with Morris water maze. Sample group was electrolytically lesioned on nucleus basalis of Meynert(nbM), and then daily treated with the medicine for two months. Control group with nbM lesion, and sham group with the sham operation were treated the vehicle for the same duration. The following results were observed. 1. As the learning trials of Morris water maze were proceeded, sham group showed the escape latency from $54.7{\pm}2.28$ seconds in 1st trial to $13.3{\pm}3.27$ seconds in 7th. The control group showed the escape latency from $58.0{\pm}1.78$ seconds in 1st trial to $51.3{\pm}3.52$ seconds in 7th. The sample group showed the escape latency from $57.0{\pm}2.21$ seconds in 1st trial to $28.4{\pm}4.82$ seconds in 7th. Therefore, these data shows that all three groups were improved in learning capacity as trials were proceeded, but the sample group showed more prominent improvement in learning compared with the control group(p<0.05). 2. In memory retention test of Morris water maze that counts the staying time in the target area during 30 seconds of freely swimming period, sham group stayed for $4.81{\pm}1.15$ seconds, the control group stayed for $1.27\pm}0.78$ seconds, and the sample group stayed for $4.17{\pm}1.47$ seconds. The analysis of the memory retention data shows that the sample group marked more improvement in memory retention compared with the control group, but could not obtained statistically significant result(p<0.05). With the experimental results above, Hyangbujapalmultang can be supposed to have the improving effects on the learning of AD model rats induced by electrolytic lesion of nbM.

• Toxicological Research
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• v.17
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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.

• Food Quality and Culture
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• v.1 no.1
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• pp.46-57
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• 2007

The purpose of the present study was to examine the nutrient intake status of elderly dementia patients. We surveyed the dietary intake of 50 demented elderly patients receiving a regular diet, who were hospitalized in a geriatric hospital in Yongin, Gyeonggi-do. The average age of the subjects was $79.6{\pm}6.5$ for the males and $80.5{\pm}6.3$ for the females. The average heights were $169.5{\pm}6.0\;cm$ (males) and $154.6{\pm}5.2\;cm$ (females), and the average weights were $58.5{\pm}7.4$ (males) and $51.7{\pm}8.9\;kg$ (females). Depending on the type of dementia, the male patients showed significant differences in their intakes of vegetable protein, fiber, total iron, and non-heme iron between the Alzheimer's disease (AD) and the vascular dementia (VD) groups, and the female patients showed significant differences in their intakes of total protein, phosphorus, zinc, and vitamin $B_6$ between the two groups. The male patients showed significant differences in their intakes of animal-source calcium and carotene according to ability to self-feed. According to physical activity, the male patients showed significant differences in vegetable fat and vitamin A intake, and the females showed significant differences in their intakes of total protein, animal protein, fiber, ash, total calcium, vegetable-source calcium, animal-source calcium, phosphorous, total iron, non-heme iron, heme iron, sodium, vitamins $B_1$, $B_2$, $B_6$, niacin, vitamin C, folate, and potassium. We found that the patients consumed excessive protein, but low amounts of calcium, vitamin $B_2$, and folate. Also, the patients' physical activity abilities appeared to affect their nutrient intakes.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.4
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• pp.173-179
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• 2004

Amyloid ${\beta}-peptide\;(A{\beta})$ contributes to the pathogenesis of Alzheimer's disease (AD), causing neuronal death through apoptosis. In this study, the neuroprotective role of BF-7, extracted form sericultural product, was examined against $A{\beta}-induced$ toxicity in cultured human neuronal cell SKN-SH. In order to know if the BF-7 has positive role on the cognition and memory in human, the mixture of BF-7, DHA and EPA (BDE) was examined using Rey Kim and K-WAIS test with 50 healthy high school student. We report here that BDE significantly attenuated $A{\beta}-induced$ apoptosis through the reduction of ROS accumulation, and diminished caspase-like protease activity. Moreover, the memory index and memory preservation, and attentative concentration of BDE treated group for 1 month were significantly improved, in contrast to the case of placebo control treated with DHA and EPA. This result represent that the BF-7 play significant positive role on learning memory. Taken together, our result suggested the natural product BF-7 is a good substance for the brain functionally and physiologically.