• Food Science and Biotechnology
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• 제17권3호
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• pp.489-494
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• 2008

In order to develop a potent antidementia $\beta$-secretase inhibitor from phytochemicals, $\beta$-secretase inhibitory activities of extracts from many medicinal plants and herbs were determined. Water extracts from Rubus coreanus showed the highest $\beta$-secretase inhibitory activity of 84.5%. After purification of the $\beta$-secretase inhibitor from R. coreanus using systematic solvent extraction, ultrafiltration, Sephadex G-10 column chromatography, and reverse-phase high performance liquid chromatography (HPLC), a purified $\beta$-secretase inhibitor with $IC_{50}$ inhibitory activity of $6.3{\times}10^3\;ng/mL$ ($1.56{\times}10^{-6}\;M)$ was obtained with a 0.08% solid yield. The molecular mass of the purified $\beta$-secretase inhibitor was estimated to be 576 Da by liquid chromatography-mass spectrometry (LC-MS) and $\beta$-secretase inhibitor also is a new tetrapeptide with the sequence Gly-Trp-Trp-Glu. The purified $\beta$-secretase inhibitory peptide inhibited $\beta$-secretase non-competitively and also show less inhibition on trypsin, however no inhibition on other proteases such as $\alpha$-secretase, chymotrypsin, and elastase.

• Fisheries and Aquatic Sciences
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• 제21권5호
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• pp.13.1-13.8
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• 2018

Amyloid plaque, also called senile plaque, the product of aggregation of ${\beta}$-amyloid peptides ($A{\beta}$), is observed in brains of the patients with Alzheimer's disease (AD) and is one of the key factors in etiology of the disease. In this study, hydrolysates obtained from the sea hare (Aplysia kurodai) were investigated for ${\beta}$-secretase inhibitory peptide. The sea hare's muscle protein was hydrolyzed using six enzymes in a batch reactor. Trypsin hydrolysate had highest ${\beta}$-secretase inhibitory activity compared to the other hydrolysates. ${\beta}$-secretase inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. ${\beta}$-secretase inhibitory peptide was identified as eight amino acid residues of Val-Ala-Ala-Leu-Met-Leu-Phe-Asn by N-terminal amino acid sequence analysis. $IC_{50}$ value of purified ${\beta}$-secretase inhibitory peptide was $74.25{\mu}M$, and Lineweaver-Burk plots suggested that the peptide purified from sea hare muscle protein acts as a competitive inhibitor against ${\beta}$-secretase. Results of this study suggest that peptides derived from sea hare muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• Fisheries and Aquatic Sciences
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• 제19권2호
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• pp.11.1-11.7
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• 2016

In this study, purified peptides from shrimp waste hydrolysates (SWHs) were examined for their inhibitory effects against ${\beta}$-secretase. During consecutive purification using a Sephadex G-25 column chromatography and high performance liquid chromatography on a C18 column, a potent ${\beta}$-secretase inhibitory peptide Asp-Val-Leu-Phe-His (629 Da) was isolated and identified from SWH24 by Q-TOF MS/MS and the $IC_{50}$ value was determined to be $92.70{\mu}M$. The ${\beta}$-secretase inhibition patterns of the purified peptides were found to be competitive. Among synthesized ${\beta}$-secretase inhibitory peptides, Leu-Phe-His had higher ${\beta}$-secretase inhibitory activity than the others. The result of this study suggests that the ${\beta}$-secretase inhibitory peptide derived from SWH24 could be potential candidates to develop nutraceuticals and pharmaceuticals.

• 한국키틴키토산학회지
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• 제23권4호
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• pp.220-227
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• 2018

Amyloid plaque is a product of aggregation of ${\beta}$-amyloid peptide ($A{\beta}$) and is an important factor in the pathogenesis of Alzheimer's Disease (AD). $A{\beta}$ is a major component of amyloid plaque and vascular deposits in the AD brain. The enzyme ${\beta}$-secretase is required for the production of $A{\beta}$; thus, prevention of the formation of $A{\beta}$ through the inhibition of ${\beta}$-secretase is a major focus in the study of the treatment of AD. In this study, we investigated ${\beta}$-secretase inhibitory activity of an Arctoscopus japonicus peptide. An Alcalase hydrolysate had the highest ${\beta}$-secretase inhibitory activity. A ${\beta}$-secretase inhibitory activity peptide was separated using ion exchange column chromatography (carboxy-methyl: CM, quaternary methyl ammonium: QMA) and reverse phase high performance liquid chromatography (RP-HPLC) on a C18 column. The $IC_{50}$ value of the purified peptide was $248.2{\pm}1.73{\mu}g/mL$. The ${\beta}$-secretase inhibitory peptide was identified as a six amino acid residue of Gly-Pro-Val-Gly-Ala-Pro (MW: 497.27 Da). In cell viability experiments, the final purified fraction, the carboxy-methyl ion exchange column fraction (CM-F1) showed no significant cytotoxic effect in SH-SY5Y cells at concentrations below $100{\mu}g/mL$ in 24 h. The results of this study suggest that peptides separated from Arctoscopus japonicus may be beneficial as ${\beta}$-secretase inhibitor compounds in functional foods.

• 한국해양바이오학회지
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• 제10권1호
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• pp.1-8
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• 2018

The objective of this study was to purify and characterize the ${\beta}-secretase$ inhibitor from enzymatic hydrolysates of blackfin flounder muscle, for development of a novel anti-dementia agent that may be used in the drug or functional food industries. ${\beta}-secretase$ inhibitory peptide was purified from various enzymatic hydrolysates of blackfin flounder muscle. Among six enzymatic hydrolysates, the Alcalase hydrolysate revealed highest ${\beta}-secretase$ inhibitory activity. Consecutive purification of the blackfin flounder muscle hydrolysate using Sephadex G-25 column chromatography and octadecylsilane C18 reversed phase HPLC techniques were used to isolate a potent ${\beta}-secretase$ inhibitory peptide composed of 5 amino acids, Leu-Thr-Gln-Asp-Trp (MW: 526.7 Da). The $IC_{50}$ value of purified ${\beta}-secretase$ inhibitory peptide was $126.93{\mu}M$. Results of this study suggest that peptides derived from blackfin flounder muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• 한국미생물·생명공학회지
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• 제36권4호
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• pp.291-298
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• 2008

본 연구는 4종류의 한국산 포도를 이용하여 포도주를 제조한 후 이들의 발효와 후 발효중의 심혈관 관련 angiotensis I 전환효소 저해 확정과 혈전 용해 활성 및 항치매성 $\beta$-secretase 저해활성을 조사하였다. 발효 10일 후 모든 시료 포도주들의 항고혈압성 엔지오텐신 전환효소(ACE)저해활성은 $38.6%{\sim}58.8%$ 이었다. 그러나 후발효가 진행됨에 따라 ACE저해활성은 증가하여 세리단(Vitis hybrid) 포도주가 후발효 120일 후 최고인 76.9%에 도달하였다. 혈전용해활성은 모든 시료 포도주들에서 미약하거나 없었다. 발효 10일 후, 켐벨어리(Vitis labrusca B) 포도주가 54.8%의 가장 높은 항치매성 $\beta$-secretase저해 활성을 보였으나 후발효 120일 후에는 10% 미만으로 현저하게 감소되었다. 결론적으로 본 연구에서는 세리단 포도를 S. cerevisiae K-7 효모로 $25^{\circ}C$에서 10일간 발효 시킨 후 $4^{\circ}C$에서 120일간 후발효 시켜서 고부가가치의 생리 기능성을 가진 세리단 적포도주를 제조하였다.

• Fisheries and Aquatic Sciences
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• 제21권12호
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• pp.38.1-38.9
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• 2018

Alzheimer's disease (AD) is a disturbing and advanced neurodegenerative disease and is characterized pathologically by the accumulation of amyloid beta ($A{\beta}$) and the hyperphosphorylation of tau proteins in the brain. The deposition of $A{\beta}$ aggregates triggers synaptic dysfunction, and neurodegeneration, which lead to cognitive disorders. Here, we found that FF isolated from an eatable perennial brown seaweed E.bicyclis protect against $A{\beta}$-induced neurotoxicity in neuroblastoma cells stably transfected with two amyloid precursor protein (APP) constructs: the APP695 cDNA (SH-SY5Y-APP695swe). The FF demonstrated strong inhibitory activity for ${\beta}$-secretase ($IC_{50}$ $16.1{\mu}M$) and its inhibition pattern was investigated using Lineweaver-Burk and Dixon plots, and found to be non-competitive. Then, we tested whether FF could inhibit production of $A{\beta}$ in SH-SY5Y-APP695swe. FF inhibited the production of $A{\beta}$ and soluble-APP, residue of APP from cleaved APP by ${\beta}$-secretase. Our data show that FF can inhibit the production of $A{\beta}$ and soluble-$APP{\beta}$ via inhibition of ${\beta}$-secretase activity. Taken together these results suggest that FF may be worthy of future study as an anti-AD treatment.

• Journal of Microbiology
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• 제44권5호
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• pp.502-507
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• 2006

In a previous study, an extract of Clavicorona pyxidata DGUM 29005 mycelia demonstrated an inhibitory effect against enzyme-associated perceptual disorders. We have attempted to determine whether this mycelial extract is also capable of inhibiting the activities of acetylcholinesterase (AChE) and ${\beta}$-secretase (BACE) activity. Butanol, ethanol, and water extracts of C. pyxidata DGUM 29005 mycelia were shown to inhibit AChE activity by 99.3%, 93.7%, and 91.7%, respectively. The inhibitory value of the butanol extract was more profound than that of tacrine (95.4%). The ethanol extract also exerted an inhibitory effect against BACE activity; this fraction may harbor the potential for development into a pharmocotherapeutic modality for the treatment of Alzheimer's disease (AD) patients. Rat pheochromocytoma PC12 cells in culture were not determined to be susceptible to the cytotoxic activity evidenced by the mycelial extract. The ethanol extract inhibited endogenous AChE activity in PC12 cellular homogenates, with an $IC_{50}\;of\;67.5{\mu}g/ml$, after incubation with intact cells, and also inhibited BACE activity in a dose-dependent fashion. These results suggest that the C. pyxidata mycelial extract has the potential to enhance cholinergic function and, therefore, may perform a function in the amelioration of the cholinergic deficit observed in cases of AD, as well as other types of age-associated memory impairment.

• Mycobiology
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• 제36권3호
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• pp.195-197
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• 2008

To produce a potent antidementia $\beta$-secretase inhibitor from a mushroom, the $\beta$-secretase inhibitory activities of various mushroom extracts were determined. Methanol extracts of Lentinula edodes exhibited the highest inhibitory activity (40.1%). The inhibitor was maximally extracted when a fruiting body of L. edodes was treated with 50% methanol at 40$^{\circ}C$ for 24 h.

• 약학회지
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• 제49권2호
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• pp.168-173
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• 2005

Alzheimers disease (AD) is the most prevalent form of neurodegenerations associated with aging in the human population. This disease is characterized by the extracellular deposition of beta-amyloid (A ${\beta}$) peptide in cerebral plaques. The A ${\beta}$ peptide is derived from the ${\beta}$-amyloid precursor protein ( ${\beta}$APP). Photolytic processing of ${\beta}$APP by ${\beta}$-secretase(beta-site APP-cleaving enzyme, BASE) and ${\gamma}$-secretase generates the A ${\beta}$ peptide. Several lines of evidence support that A ${\beta}$-induced neuronal cell death is major mechanisms of development of AD. Accordingly, the ${\beta}$-and ${\gamma}$-secretase have been implicated to be excellent targets for the treatment of AD. We previously found that sesaminol glucosides have improving effect on memory functions through anti-oxidative mechanism. In this study, to elucidate possible other mechanism (inhibition of ${\beta}$-and ${\gamma}$-secretase) of sesaminol glucosides, we examined the improving effect of sesaminol glucosides in the scopolamine (1 mg/kg/mouse)-induced memory dysfunction using water maze test in the mice. Sesaminol glucosides (3.75, 7.5 mg/kg/6ml/day p.o., for 3 weeks) reversed the latency time, distance and velocity by scopolamine in dose dependent manner. Next, ${\beta}$-and ${\gamma}$-secretase activities were determined in different regions of brain. Sesaminol glucosides dose-dependently attenuated scopolamine-induced ${\beta}$-secretase activities in cortex and hippocampous and ${\gamma}$-secretase in cortex. This study therefore suggests that sesaminol glucosides may be a useful agent for prevention of the development or progression of AD, and its inhibitory effect on secretase may play a role in the improving action of sesaminol glucosides on memory function.