• Proceedings of the PSK Conference
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• 2003.04a
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• pp.202.1-202.1
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• 2003

Microglial cell can act for phagocytosis against abnormal particles in brain, which means that beta-amyloid produced from APP(amyloid precursor protein) can be phagocytosed by microglia when released. In contrast. when senile plaque has already been formed in brain cortex and hippocamphal region, microglia can also accelerate the AD pathogenesis due to chronic inflammatory action, which lead to neuron cell cytotoxicity. (omitted)

• The Korea Journal of Herbology
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• v.29 no.6
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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.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.461-470
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• 2000

Objective : Many investigators have demonstrated the protective effects of hypothermia following traumatic brain injury(TBI) in both animals and humans. It has long been recognized that mild to moderate hypothermia improves neurologic outcomes as well as reduces histologic and biochemical sequelae after TBI. In this study, two immunohistochemical staining using terminal deoxynucleotidyl-transferase-mediated biotin dUTP nick end labeling(TUNEL), staining of apoptosis, and ${\beta}$-amyloid precursor protein(${\beta}$-APP), a marker of axonal injury, were done and the authors evaluated the protective effects of hypothermia on axonal and neuronal injury after TBI in rats. Material and Method : The animals were prepared for the delivery of impact-acceleration brain injury as described by Marmarou and colleagues. TBI is achieved by allowing of a weight drop of 450gm, 1 m height to fall onto a metallic disc fixed on the intact skull of the rats. Fourty Sprague-Dawley rats weighing 400 to 450g were subjected to experimental TBI induced by an impact-acceleration device. Twenty rats were subjected to hypothermia after injury, with their rectal temperatures maintained at $32^{\circ}C$ for 1 hour. After this 1-hour period of hypothermia, rewarming to normothermic levels was accomplished over 30-minute period. Following 12 hours, 24 hours, 1 week and 2 weeks later the animals were killed and semiserial sagittal sections of the brain were reacted for visualization of the apoptosis and ${\beta}$-APP. Results : The density of ${\beta}$-APP marked damaged axons within the corticospinal tract at the pontomedullary junction and apoptotic cells at the contused cerebral cortex were calculated for each animal. In comparison with the untreated controls, a significant reduction in ${\beta}$-APP marked damaged axonal density and apoptotic cells were found in all hypothermic animals(p<0.05). Conclusion : This study shows that the posttraumatic hypothermia result in substantial protection in TBI, at least in terms of the injured axons and neurons.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.1
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• pp.43-51
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• 2006

This experiment was designed to investigate the effect of Amomum villosum(AMV) on the Alzheimer's disease. The effects of AMV extract on amyloid precursor proteins(APP), acetylcholinesterase(AChE), glial fibrillary acidic protein(GFAP) mRNA of PC-12 cell line treated by amyloid $\beta$ protein($A{\beta}$) : IL-$1{\beta}$, IL-6, TNF-$\alpha$ mRNA of THP-1 cell line treated by lipopolysaccharide(LPS) : AChE activity of PC-12 cell lysate treated by $A{\beta}$ : serum glucose, uric acid, AChE activity of memory deficit rats induced by scopolamine : behavior of memory deficit mice induced by scopolamine were investigated, respectively. AMV extract suppressed APP, AChE, GFAP mRNA in PC-12 cell treated by $A{\beta}$ : IL-$1{\beta}$, IL-6, TNF-$\alpha$ mRNA in THP-1 cell treated by LPS , AChE activity in cell lysate of PC-12 cell treated by $A{\beta}$. AMV extract increased glucose, decreased uric acid and AChE significantly in the serum of the memory deficit rats induced by scopolamine. AMV extract group showed significantly inhibitory effect on the memory deficit of mice induced by scopolamine in the experiment of Morris water maze. According to the above results, it is suggested that AMV extract might be usefully applied for prevention and treatment of Alzheimer's disease.

• Journal of Oriental Neuropsychiatry
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• v.17 no.2
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• pp.75-89
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• 2006

Objective : This experiment was designed to investigate the effect of Rhododendron simsii Planch(RSP) on the Alzheimer's disease. Method : The effects of RSP on amyloid precursor proteins(APP), acetylcholinesterase (AChE), glial fibrillary acidic protein(GFAP) mRNA of PC-12 cell treated by amyloid ${\beta}$ protein$(A{\beta})$ and $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ mRNA of THP-1 cell treated by lipopolysaccharide(LPS), AChE activity of PC-12 cell lysate treated by $A{\beta}$ and behavior of the memory deficit mice induced by scopolamine, and glucose, AChE in serum of the memory deficit mice induced by scopolamine were investigated, respectively. Result : 1. RSP suppressed APP, AChE, GFAP mRNA in PC-12 celt treated by $A{\beta}$. 2. RSP suppressed $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ mRNA in THP-1 cell treated by LPS. 3. RSP suppressed AChE activity in cell lysate of PC-12 cell treated by $A{\beta}$. 4. RSP increased glucose and decreased AChE significantly in the serum of the memory deficit mice induced by scopolamine. 5. RSP group showed significantly inhibitory effect on the scopolamine-induced impairment of teaming and. memory in the experiment of Morris water maze. Conclusion : According to the above results, it is suggested that RSP might be usefully applied for prevention and treatment of Alzheimer's disease and memory deficit symptom.

• Molecules and Cells
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• v.40 no.9
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• pp.613-620
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• 2017

The most common form of senile dementia is Alzheimer's disease (AD), which is characterized by the extracellular deposition of amyloid ${\beta}-peptide$ ($A{\beta}$) plaques and the intracellular formation of neurofibrillary tangles (NFTs) in the cerebral cortex. Tau abnormalities are commonly observed in many neurodegenerative diseases including AD, Parkinson's disease, and Pick's disease. Interestingly, tau-mediated formation of NFTs in AD brains shows better correlation with cognitive impairment than $A{\beta}$ plaque accumulation; pathological tau alone is sufficient to elicit frontotemporal dementia, but it does not cause AD. A growing amount of evidence suggests that soluble $A{\beta}$ oligomers in concert with hyperphosphorylated tau (pTau) serve as the major pathogenic drivers of neurodegeneration in AD. Increased $A{\beta}$ oligomers trigger neuronal dysfunction and network alternations in learning and memory circuitry prior to clinical onset of AD, leading to cognitive decline. Furthermore, accumulated damage to mitochondria in the course of aging, which is the best-known nongenetic risk factor for AD, may collaborate with soluble $A{\beta}$ and pTau to induce synapse loss and cognitive impairment in AD. In this review, I summarize and discuss the current knowledge of the molecular and cellular biology of AD and also the mechanisms that underlie $A{\beta}-mediated$ neurodegeneration.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.2
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• pp.397-404
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• 2009

For standardization of LMK02 quality, Ginsenoside Rg3 of Red Ginseng and Decursin of Angelica gigas Nakai in the constituents of LMK02 were estimated as indicative components. From LMK02 water extract, has been used in vitro test for its beneficial effects on neuronal survival and neuroprotective functions, particularly in connection with APP-related dementias and Alzheimer's disease (AD). $A{\beta}$ oligomer 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 dementia. We determined that oligomer amyloid-${\beta}$ ($A{\beta}$) have a profound attenuation in the increase in rat hippocampus H19-7 cells from. Experimental evidence indicates that LMK02 protects against neuronal damage from cells, but its cellular and molecular mechanisms remain unknown. Using a hippocampus cell line on $A{\beta}$ oligomer-induced neuronal cytotoxicity, we demonstrated that LMK02 inhibits formation of $A{\beta}$ oligomer, which are the behavior, and possibly causative, feature of AD. In the Red Ginseng, the average amounts of Ginsenoside Rg3 were $47.04{\mu}g/g$ and $42.3{\mu}g/g$, 90 % of its weight were set as a standard value. And, in the Angelica gigas Nakai, the average amounts of Decursin were 2.71 mg/g and 2.44mg/g, 90 % of its weight were also set as a standard value. The attenuated $A{\beta}$ oligomer in the presence of LMK02 was observed in the conditioned medium of this $A{\beta}$ oligomer-induced cells under in vitro. In the cells, LMK02 significantly activated antiapoptosis and decreased the production of ROS. These results suggest that neuronal damage in AD might be due to two factors: a direct $A{\beta}$ oligomer toxicity and multiple cellular and molecular neuroprotective mechanisms, including attenuation of apoptosis and direct inhibition of $A{\beta}$ oligomer, underlie the neuroprotective effects of LMK02 treatment.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.04a
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• pp.123-135
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• 2006

Alzheimer's disease (AD) is the most common form of dementia in the aging population and is clinically characterized by a progressive loss of cognitive abilities. Pathologically, it is defined by the appearance of senile plaques - extracellular insoluble, congophilic protein aggregates composed of amyloid $\beta$ (A$\beta$) and neurofibrillary tangles (NFTs) - inyracellular lesions consisting of paired helical filaments from hyperphosphorylated cytoskeletal tau protein as described by Alois Alzheimer a century ago. These hallmarks still serve as the major criteria for a definite diagnosis of the disease. Consequently, one of the key strategy for drug development in this disease area focuses on reducing the concentration of cerebral A$\beta$ plaque by using substances that inhibit A$\beta$ fibril formation. We focused on developing inhibitors by synthesizing several kinds of aromatic molecules. The synthetic compounds were initially screened to evaluate the effective compound by tioflavin T fluorescence assay. The selected effective compounds were tested cytotoxicity and protective effect from A$\beta$-induced neuronal toxicity by cell based MTT assay with HT22 hippocampal neurons. The BBB permeability on effectors was also tested in in vitro co-culture model(HUVEC/C6 cell line). The behavior test wea carried out in mutant APP/PS1 transgenic mouse model of Alzheimer's disease. And inhibition of A$\beta$ fibril formation by the effective compound was monitored with transmitted electron microscopic images.

• BMB Reports
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• v.43 no.10
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• pp.649-655
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• 2010

Alzheimer's disease (AD) is the most common age-dependent neurodegenerative disorder and shows progressive memory loss and cognitive decline. Intraneuronal filaments composed of aggregated hyperphosphorylated tau protein, called neurofibrillary tangles, along with extracellular accumulations of amyloid $\beta$ protein (A$\beta$), called senile plaques, are known to be the neuropathological hallmarks of AD. In light of recent studies, epigenetic modification has emerged as one of the pathogenic mechanisms of AD. Epigenetic changes encompass an array of molecular modifications to both DNA and chromatin, including transcription factors and cofactors. In this review, we summarize how DNA methylation and changes to DNA chromatin packaging by post-translational histone modification are involved in AD. In addition, we describe the role of SIRTs, histone deacetylases, and the effect of SIRT-modulating drugs on AD. Lastly, we discuss how amyloid precursor protein (APP) intracellular domain (AICD) regulates neuronal transcription. Our understanding of the epigenomes and transcriptomes of AD may warrant future identification of novel biological markers and beneficial therapeutic targets for AD.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.85-91
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• 2017

Alzheimer's disease (AD) is a progressive neurodegenerative disorder of insidious onset that causes gradual loss of memory and cognitive function, and it is the most common form of dementia in the elderly. AD is characterized by neuritic plaques and neurofibrillary tangles in the brain, together with loss of neuronal cells. The major neuropathological hallmark of AD is the accumulation of extracellular neurotoxic ${\beta}-amyloid$ ($A{\beta}$) peptides, such as $A{\beta}1-42$, in the brain. In the present study, we investigated the effect of sargachromenol (SCM), sargaquinoic acid (SQA) and sargahydroquinoic acid (SHQA) isolated from Sargassum serratifoilum ethanol extract (SSE) on $A{\beta}$ production in vitro using APP751-transfected Chinese hamster ovary cells (CHO-751). CHO-751 cells were treated with various concentrations of SSE, SCM, SQA and SHQA, and the level of extracellular $A{\beta}1-42$ was evaluated by enzyme-linked immunosorbent assay. SSE and SHQA reduced the production of $A{\beta}1-42$ in CHO-751 cells. Therefore, SHQA isolated from S. serratifolium has potential as an inhibitor of neurotoxic $A{\beta}$ peptide production.