• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.1
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• pp.33-39
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• 2016

Alzheimer's disease(AD), one of the most common forms of dementia, is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of β-amyloid(Aβ) peptides of 40-42 residues. Aβ has been believed to be neurotoxic and now is also considered to have a role on the mechanism of memory dysfunction. Only a few acetylcholinesterase(AChE) inhibitors have been developed for treatment of AD, although the numbers of patients are rapidly increasing within aging society. Here, we show that ethanol extract of Rosae Rugosae Flos(RR) or its butanol fraction reduce the enzyme activity of AChE and BACE1(β-site APP cleaving enzyme 1). Furthermore, We found that RR inhibits Aβ aggregation and removes Aβ aggregates by Transmission electron microscopy(TEM). In addition, RR reduces the free radical of 2, 2-diphenyl-1-picrylhydrazyl(DPPH). We suggest that Rosae Rugosae Flos may be useful as a herbal medicine to treat AD.

• Toxicological Research
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• v.29 no.4
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• pp.235-240
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• 2013

Extracellular accumulation of amyloid beta protein ($A{\beta}$) plays a central role in Alzheimer's disease (AD). Some metals, such as copper, lead, and aluminum can affect the $A{\beta}$ accumulation in the brain. However, the effect of mercury on $A{\beta}$ accumulation in the brain is not clear. Thus, this study was proposed to estimate whether mercury concentration affects $A{\beta}$ accumulation in PC12 cells. We treated 10, 100, and 1000 nM $HgCl_2$ (Hg) or $CH_3HgCl_2$ (MeHg) for 48 hr in PC12 cells. After treatment, $A{\beta}_{40}$ in culture medium increased in a dose- and time-dependent manner. Hg and MeHg increased amyloid precursor protein (APP), which is related to $A{\beta}$ production. Neprilysin (NEP) levels in PC12 cells were decreased by Hg and MeHg treatment. These results suggested that Hg induced $A{\beta}$ accumulation through APP overproduction and reduction of NEP.

• Korean Journal of Pharmacognosy
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• v.46 no.1
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• pp.72-77
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• 2015

One of the most common forms of dementia, Alzheimer's disease (AD) is a progressive neurodegenerative disorder symptomatically characterized by impairment in memory and cognitive abilities. AD is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}$-amyloid ($A{\beta}$) peptides, believed to be neurotoxic and now is also considered to have a role on the mechanism of memory dysfunction. In this study, we tested that MeOH extract of Impatiens balsamina L. (IBM) affects on the processing of APP from the APPswe over-expressing Neuro2a cell line. We found that IBM increased over 2 folds of the $sAPP{\alpha}$ secretion level, a main metabolite of ${\alpha}$-secretase. We shown that IBM reduced the secretion level of $A{\beta}42$ and $A{\beta}40$ without cytotoxicity. BACE (${\beta}$-site APP cleaving enzyme) FRET assay shown that BACE activity was specifically decreased in the presence of IBM. We suggest that Impatiens balsamina L. may be an useful source to develop a herbal medicine of BACE inhibitor for Alzheimer's disease.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1225-1228
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• 2005

C-terminal fragments of APP (APP-CTs), that contain A$\beta$ sequence, are found in neurotic plaques, neurofibrillary tangles and the cytosol of lymphoblastoid cells obtained from AD patients. CT26, Thr639-Asp664 (TVIVITLVMLKKKQYTSIHH GVVEVD) includes not only the transmembrane domain but also the cytoplasmic domain of APP. This sequence is produced from cleavage of APP by caspase and $\gamma$-secretase. In this study, the solution structure of CT26 was investigated using NMR spectroscopy and circular dichroism (CD) spectropolarimeter in various membrane-mimicking environments. According to CD spectra and the tertiary structure of CT26 determined in TFE-containing aqueous solution, CT26 has an α-helical structure from $Val^{2}\;to\;Lys^{11}$ in TFE-containing aqueous solution. However, according to CD data, CT26 adopts a $\beta$-sheet structure in the SDS micelles and DPC micelles. This result implies that CT26 may have a conformational transition between $\alpha$-helix and $\beta$-sheet structure. This study may provide an insight into the conformational basis of the pathological activity of the C-terminal fragments of APP in the model membrane.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.408-416
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• 2022

This study investigated the physicochemical properties and physiological activities of jelly prepared from gelatin, sugar, bokbunja extract, and different amounts (0, 0.5, 1, 2 and 3%) of fermented sea tangle Saccharina japonica powder (FSP). The jelly moisture, pH, and sugar content slightly increased with increasing the FSP content. Hardness, springiness, gumminess, chewiness, and cohesiveness also increased with increasing FSP concentration. Jelly antioxidant activity did not change significantly with increasing FSP. In contrast, alcohol dehydrogenase and aldehyde dehydrogenase activities in the jellies increased significantly with increasing FSP concentration. β-secretase inhibitory activity in jellies also increased with increasing FSP concentration. Jellies containing 0.5 or 1% FSP achieved the highest overall sensory acceptance scores. Taken together, these data indicate that addition of FSP to jelly appears to improve its quality and physiological activities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.526-531
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• 2023

This study investigated the ingredients, anti-aging and anti-dementia activities of the Korean marine algae Silvetia siliquosa. The S. siliquosa solvent extracts were prepared with 70% ethanol, 80% methanol, and distilled water. The extraction yield range of various solvent extracts was 15.82-49.98%. The ethanol and methanol extracts had higher tyrosinase and collagenase inhibitory activities than those of the water extract. Meanwhile, all extracts exhibited high elastase inhibitory activity. Conversely, the methanol and water extracts exhibited the highest acetylcholinesterase inhibitory activity (IC₅₀, 0.40 mg/mL) and β-secretase inhibitory activity (IC₅₀, 0.81 ㎍/mL), respectively. These results indicate that S. siliquosa may be useful in food and pharmaceutical materials as a cosmetic and functional.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.2
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• pp.137-144
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• 2024

In this study, we investigated the antioxidant and physiological activities of the Korean marine algae, Enteromorpha compressa. Solvent extracts of E. compressa were prepared using 70% ethanol, 80% methanol, and water, with extraction yields ranging from 9.55% to 25.67%. The total polyphenol and flavonoid contents ranged from 20.76-28.41 mg/g and 2.56-18.59 mg/g, respectively. Compared with the water extract, the ethanol and methanol extracts were found to have higher antioxidant activities. All three extracts were found to promote alcohol dehydrogenase and aldehyde dehydrogenase activities in a concentration-dependent manner, whereas the methanol and ethanol extracts were established to have the highest angiotensin-converting enzyme (ACE) inhibitory activity (IC₅₀=1.40 ㎍/mL) and β-secretase inhibitory activity (IC₅₀=0.17 ㎍/mL), respectively. These findings thus indicate that E. compressa could have beneficial application as a supplementary antioxidant and functional constituent in food and pharmaceutical materials.

• BMB Reports
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• v.44 no.2
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• pp.135-139
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• 2011

Chronic alcohol consumption contributes to numerous diseases, including cancers, cardiovascular diseases, and liver cirrhosis. Epidemiological studies have shown that excessive alcohol consumption is a risk factor for dementia. Along this line, Alzheimer's disease (AD) is the most common form of dementia and is caused by the accumulation of amyloid-$\beta$ ($A{\beta}$ plaques in neurons. In this study, we hypothesized that chronic ethanol consumption is associated with pathological processing of APP in AD. To investigate the relationship between chronic alcohol consumption and $A{\beta}$ production, brain samples from rats fed an alcohol liquid diet for 5 weeks were analyzed. We show that the expression levels of APP, BACE1, and immature nicastrin were increased in the cerebellum, hippocampus, and striatum of the alcohol-fed group compared to the control group. Total nicastrin and PS1 levels were induced in the hippocampus of alcohol-fed rats. These data suggest that the altered expression of APP and $A{\beta}$-producing enzymes possibly contributes to the chronic alcohol consumption-mediated pathogenesis of AD.

• BMB Reports
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• v.43 no.10
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• pp.704-709
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• 2010

The Swedish mutation (K595N/M596L) of amyloid precursor protein (APP-swe) has been known to increase abnormal cleavage of cellular APP by Beta-secretase (BACE), which causes tau protein hyperphosphorylation and early-onset Alzheimer's disease (AD). Here, we analyzed the effect of APP-swe in global gene expression using deep transcriptome sequencing technique. We found 283 genes were down-regulated and 348 genes were up-regulated in APP-swe expressing H4-swe cells compared to H4 wild-type cells from a total of approximately 74 million reads of 38 base pairs from each transcriptome. Two independent mechanisms such as kinase and phosphatase signaling cascades leading hyperphosphorylation of tau protein were regulated by the expression of APP-swe. Expressions of catalytic subunit as well as several regulatory subunits of protein phosphatases 2A were decreased. In contrast, expressions of tau-phosphorylating glycogen synthase kinase $3\beta$(GSK-3$\beta$), cyclin dependent kinase 5 (CDK5), and cAMP-dependent protein kinase A (PKA) catalytic subunit were increased. Moreover, the expression of AD-related Aquaporin 1 and presenilin 2 expression was regulated by APP-swe. Taken together, we propose that the expression of APP-swe modulates global gene expression directed to AD pathogenesis.

• Biomolecules & Therapeutics
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• v.15 no.1
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• pp.34-39
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• 2007

Alzheimer's disease (AD) is an abnormal accumulation of the ${\beta}$-amyloid protein $(A{\beta})$ in specific brain region. It has been speculated that disturbance in cholesterol homeostasis may contribute to the etiology of AD by increasing $A{\beta}$ generation. However, conclusive evidence and possible mechanism has not been reported. In the present study, we demonstrated that rabbits treated with 0.5% cholesterol for 16 weeks increased serum total cholesterol, triacylglycerol, and low-density lipoprotein levels. $A{\beta}$ levels is higher in the hippocampus of brain in cholesterol dieted rabbits than that of normal diet rabbis. Expression and activities of ${\beta}-$ and ${\gamma}-$ secretases, the enzymes that cleave ${\beta}$-amyloid precursor protein to generate $A{\beta}$, were also increased in hippocampus of high cholesterol dieted rabbit than those of normal dieted rabbits. Our results suggest that high cholesterol diet may be associated with increased $A{\beta}$ accumulation in the brain of rabbits, and suggest that high cholesterol diet may be causal factor in the development or progression of AD.