• Title/Summary/Keyword: Amyloid

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Study on the effect of Buthus martensi Karsch extract on thrombosis and brian damage (전갈(全蝎) 추출물(抽出物)이 혈전증(血栓症), 전뇌허혈(全腦虛血) 및 뇌세포독성(腦細胞毒性)에 미치는 영향(影響))

  • Baek, Myung-Hyun;Hwang, Yong-Geun;Jeong, Ji-Cheon;Kang, Jeong-Jun;Kim, Sung-Hoon
    • The Journal of Dong Guk Oriental Medicine
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    • v.8 no.1
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    • pp.171-190
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    • 1999
  • This following is effect of Buthus martensi Karsch(BMK) extract on dextran-thrombus model, KCN-induced coma, cytotoxicity of brain etc. BMK extract significantly increased number of platelet and fibrogen and significantly shortened the prothrombin time as compared with control group treated with dextran. BMK extract didn't affect the changes of hematocrit as compared with control group treated with dextran. BMK extract induced a significant inhibition of human platelet aggregation induced by thrombin and ADP but did not affect human platelet aggregation induced by collagen. BMK extract showed a protective effect on pulmonary thrombosis induced by collagen and epinephrine. BMK extract prolonged the duration of KCN-induced coma and showed a protective effect on cytotoxicity of PC12 cells induced by amyloid ${\beta}$ protein(25-35) in a dose dependent manner. These results suggested that BMK extract might be usefully applied for prevention and treatment of thrombosis and brain damage.

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Effect of Lignan Components from Schizandra chinensis on Beta-amyloid Aggregation Inhibition and Dissociation (오미자 리그난 화합물의 베타-아밀로이드간 결합 억제 및 해리 효과)

  • Yu, Ho Jin;Yoon, Mi So;Kim, Do Yoon;Won, Kyung-Jong;Kim, Bokyung;Jang, Sang-Hee;Lee, Hwan Myung
    • YAKHAK HOEJI
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    • v.56 no.5
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    • pp.293-298
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    • 2012
  • The present study tested the effect of Schizandra chinensis lignan compounds, Gomisin A and Schizandrin, on the aggregation and dissociation of beta-amyloid $(A{\beta})_{1-42}$ to explore a possible therapeutic target for Alzheimer's disease. Gomisin A significantly inhibited the $A{\beta}_{1-42}$ aggregation in a dose dependent manner, but did not induced the dissociation of aggregated $A{\beta}_{1-42}$. On the other hand, Schizandrin significantly suppressed the aggregation and dissociation of $A{\beta}_{1-42}$. These results suggest that Gomisin A and Schizandrin, which are known as biologically active ingredients from Schizandra chinensis, may be potentially useful target molecules to develop a drug for the prevention or treatment of Alzheimer's disease.

Enhancement of Type A Macrophage Scavenger Receptor Expression by Ginsenoside Rg3 in Rat Microglia (흰쥐 뇌 소교세포에서 진세노사이드 Rg3의 Type A Macrophage Scavenger Receptor 발현 증진효과)

  • Joo, Seong-Soo;Hwang, Kwang-Woo;Lee, Do-Ik
    • YAKHAK HOEJI
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    • v.49 no.2
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    • pp.147-150
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    • 2005
  • Macrophage scavenger receptors (MSRs) induce microglial interaction with ${\beta}$-amyloid fibrils (fA${\beta}$) that are associated with Alzheimer's disease (AD). Although microglia are know n to have a dual effect on formation of plaque and clearance of fA${\beta}$ in the AD brain, receptor-mediated phagocytosis is a very important tool for preventing amyloid plaque via activated microglia in the early stage of AD. In the study, we examined whether ginsonoside Rg3 enhances the microglial Phagocytosis of A${\beta}$1-42 through Phagocytosis assay, gene expression (RT-PCR) and protein assay (western blots) for the cell responsiveness presented between Rg3-treated and non-treated groups. Fluro-labeled Ac-LDL and E.coli particles were used as control proteins for phagocytosis. In previous studies, this was a particularly interesting property of Rg3 in the stimulation and phagocytosis of macrophages in the periphery. We report here that ginsenoside Rg3 increased the expression of type-A MSR (MSR-A) in microglia and thus accelerated the phagocytosis with an effective degradation of engulfed fA${\beta}$. This result suggests that Rg3 may play an important role in removing fA${\beta}$ by enhancing the receptor-mediated phagocytosis. In addition, Rg3 could be a potential candidate for balancing the rate of production of fA${\beta}$ in AD brain.

Ethanol Extract of Three Plants of Curcuma longae Radix, Phellinus linteus, and Scutellariae Radix Inhibits Amyloid $\beta$ Protein (25-35)-Induced Neurotoxicity in Cultured Neurons and Memory Impairment in Mice (Curcuma longae Radix, Phellinus linteus 및 Scutellariae Radix 혼합추출물의 $A{\beta}$ (25-35) 유도 배양신경세포독성 및 마우스기억손상 억제효과)

  • Kim, Joo-Youn;Jeong, Ha-Yeon;Ban, Ju-Yeon;Yoo, Jae-Kuk;Bae, Ki-Hwan;Seong, Yeon-Hee
    • Korean Journal of Medicinal Crop Science
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    • v.17 no.6
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    • pp.388-396
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    • 2009
  • The present study investigated an ethanol extract (HS0608) of a mixture of three medicinal plants of Curcuma longae radix, Phellinus linteus, and Scutellariae radix for possible neuroprotective effects on neurotoxicity induced by amyloid $\beta$ protein ($A{\beta}$) (25-35) in cultured rat cortical neurons and antidementia activity in mice. Exposure of cultured cortical neurons to $10\;{\mu}M$ $A{\beta}$ (25-35) for 36 h induced neuronal apoptotic death. At $1-50\;{\mu}g/m{\ell}$, HS0608 inhibited neuronal death, elevation of intracellular calcium concentration ($[Ca^{2+}]_i$), and generation of reactive oxygen species (ROS) induced by $A{\beta}$ (25-35) in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of ICR mice with 15 nmol $A{\beta}$ (25-35) was inhibited by chronic treatment with HS0608 (25, 50 and 100 mg/kg, p.o. for 7 days) as measured by a passive avoidance test. From these results, we suggest that the antidementia effect of HS0608 is due to its neuroprotective effect against $A{\beta}$ (25-35)-induced neurotoxicity and that HS0608 may have a therapeutic role in preventing the progression of Alzheimer's disease.

Alzheimer's Disease-linked Swedish Amyloid Precursor Protein Mutation Induces Cell Death by Increasing Reactive Oxygen Species Generation

  • Kim Hye Sun;Lee Jun Ho;Kim Eun Mee;Lee Jean Pyo;Suh Yoo Hun
    • Environmental Mutagens and Carcinogens
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    • v.25 no.1
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    • pp.19-24
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    • 2005
  • The Swedish double mutation (KM670/671NL) of amyloid precursor protein (Swe-APP) is associated with early-onset familial Alzheimer's disease (FAD) and increases amyloid beta peptide production. Although APP/A/3 mediated neurotoxicity is observed both in vitro and in vivo, the relationship between mutant APP expression, A/3 production, and neuronal death observed in the brains of FAD patients remains to be elucidated. In this study, we investigated the mechanisms of Swe-APP-induced cell death in HEK293 and NGF-differentiated PC 12 cells. We found that the expression of Swe-APP induced cytochrome C relase, activation of caspase 3 in HEK 293 and NGF-differentiated PC 12 cells. We also show that the reactive oxygen species (ROS) was detected in Swe-APP expressing HEK 293 cells and NGF-differentiated PC 12 cells and that pretreatment with vitamine E attenuated the cellular death, cytochrome C release induced by Swe-APP expression, indicating the involvement of free radical in these processes. These results suggest one of possible apoptotic mechanisms of Swe-APP which could occur through cytochrome C release from mitochondria and this apoptosis inducing effects could be at least in part, due to ROS generation by Swe-APP expression.

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Antioxidant Activity and Protective Effect of Caffeic Acid against Oxidative Stress Induced by Amyloid Beta and LPS in C6 Glial Cells (Caffeic Acid의 항산화 활성 및 Amyloid beta와 LPS에 의한 C6 Glial 세포의 산화적 스트레스 보호 효과)

  • Kim, Ji Hyun;Wang, Qian;Lee, Sanghyun;Cho, Eun Ju
    • Korean Journal of Pharmacognosy
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    • v.46 no.2
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    • pp.109-115
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    • 2015
  • This study was investigated the radical scavenging effect and the protective activity of caffeic acid (CA) against oxidative stress. CA showed strong 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and hydroxyl radical ( OH) scavenging activity, showing 42.00% and 87.22% at 5 μM concentration of DPPH and ·OH scavenging activity, respectively. Furthermore, we studied protective activity of CA from amyloid beta (A${\beta}$25-35) and lipopolysaccharide (LPS) induced neuronal cell damage and neuronal inflammation using C6 glial cells. The treatment of A${\beta}$25-35 to C6 glial cell showed declines in cell viability and high generation levels of reactive oxygen species (ROS). However, the treatment of CA increased cell viability. The treatment of 5 ${{\mu}M}$ CA led to the elevation of cell viability from 59.28% to 81.22%. In addition, the production of ROS decreased cellular levels of ROS by the treatment of CA. The treatment of LPS to C6 glial cells increased significant elevation of nitric oxide (NO) production, while CA decreased NO production significantly. The production of NO increased by the treatment of LPS to 131.08%, while CA at the concentration of 1 ${{\mu}M}$ declined the NO production to 104.86%. The present study indicated thatCA attenuated A${\beta}$25-35-induced neuronal oxidative stress and inflammation by LPS, suggesting as a promising agent for the neurodegenerative diseases.

The Protective Effects of the Ethyl Acetate Fraction and Flavonoids from Taraxacum coreanum against Oxidative Stress in Neuronal Cells Induced by Hydrogen Peroxide and Amyloid Beta (흰민들레 Ethyl Acetate 분획물 및 Flavonoid 화합물의 Hydrogen Peroxide와 Amyloid Beta에 의한 신경세포의 산화적 스트레스 보호 효과)

  • Lee, Ah Young;Choi, Ji Myung;Lee, Sullim;Kim, Hyun Young;Lee, Sanghyun;Cho, Eun Ju
    • Korean Journal of Pharmacognosy
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    • v.44 no.3
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    • pp.263-268
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    • 2013
  • The protective role against oxidative stress under cellular system using C6 glioma cells was studied using the ethyl acetate (EtOAc) fraction, luteolin (1), and luteolin-7-glucoside (2) of Taraxacum coreanum. C6 glioma cells showed low cell viability and high generation of reactive oxygen species (ROS) by the treatment with generator of hydrogen peroxide ($H_2O_2$) and amyloid beta ($A{\beta}_{25-35}$). However, the treatment of the EtOAc fraction attenuated the cellular oxidative stress, resulting in significant elevation of cell viability. In addition, the production of ROS formation was also decreased by the treatment of the EtOAc fraction. Compounds 1 and 2 were isolated from the EtOAc fraction, and the protective effect was evaluated. Compounds 1 and 2 led to the increase of cell viability and decrease of production of ROS against oxidative stress by $H_2O_2$ and $A{\beta}_{25-35}$. The present study indicated that the EtOAc fraction, compounds 1 and 2 from T. coreanum demonstrated protective effects against oxidative stress, suggesting the preventive role against neurodegenerative diseases.

Study on the Inhibitory Effect of Anti-Alzheimer in CT105-induced Neuro 2A Cell Lines by Gamiyaungshinhwan Water Extract (가미녕신환(加味寧神丸)이 CT105로 유도된 Neuro2A 세포주에서의 항치매 효과(效果))

  • Bang, Jae-Sun;Yoon, Hyun-Duk;Shin, Oh-Chul;Shin, Yoo-Jung;Park, Chi-Sang
    • The Journal of Internal Korean Medicine
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    • v.27 no.3
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    • pp.603-616
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    • 2006
  • The water extract of Gamiyaengshinhwan (GYH), has been used in vitro tests for its beneficial effects on neuronal survival and neuroprotective functions, particularly in connection with CT105-related dementias and Alzheimer's disease(AD). CT105 derived from proteolytic processing of the $\beta$-amyloid precursor protein (APP), including the amyloid-$\beta$ peptide ($A{\beta}$), plays a critical role in the pathogenesis of Alzheimer's dementia. We determined that transfected overexpressing APP695 and $A{\beta}$ CT105 have a profound attenuation in the Increase in CT105 expressing neuro2A cells from GYH. Experimental evidence indicates that GYH protects against neuronal damage from cells, but its cellular and molecular mechanisms remain unknown. Using a neuroblastoma cell line stably expressing CT105-associated neuronal degeneration, we demonstrated that GYH inhibits formation of amyloid-$\beta$ fragment ($A{\beta}$ CT105). which are the characteristic, and possibly causative, features of AD. The decreased CT105 $A{\beta}$ in the presence of GYH was observed in the conditioned medium of this CT105-secreting cell line under in vitro. In the cells, GYH significantly attenuated mitochondrion-initiated apoptosis and decreased the activity of Bax, a key enzyme in the apoptosis cell-signaling cascade. These results suggest that neuronal damage in AD might be due to two factors: a direct CT05 toxicity and the apoptosis initiated by the mitochondria. Multiple cellular and molecular neuroprotective mechanisms, including attenuation of apoptosis and direct inhibition of CT105 aggregation, underlie the neuroprotective effects of GYH.

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Inhibitory Effects of Flavonoids Isolated from Leaves of Petasites japonicus on $\beta$-Secretase (BACE1)

  • Song, Kyung-Sik;Choi, Sun-Ha;Hur, Jong-Moon;Park, Hyo-Jun;Yang, Eun-Ju;MookJung, In-Hee;Yi, Jung-Hyun;Jun, Mi-Ra
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1165-1170
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    • 2008
  • The deposition of the amyloid $\beta}$ ($A{\beta}$)-peptide following proteolytic processing of amyloid precursor protein (APP) by $\beta$-secretase (BACE1) and $\gamma$-secretase is critical feature in the progress of Alzheimer's disease (AD). Consequently, BACE1, a key enzyme in the production of $A{\beta}$, is a prime target for therapeutic intervention in AD. In the course of searching for BACE1 inhibitors from natural sources, the ethyl acetate fraction of Petasites japonicus showed potent inhibitory activity. Two BACE1 inhibitors quercetin (QC) and kaempferol 3-O-(6"-acetyl)-$\beta$-glucopyranoside (KAG) were isolated from P. japonicus by activity-guided purification. QC, in particular, non-competitively attenuated BACE1 activity with $IC_{50}$ value of $2.1{\times}10^{-6}\;M$ and $K_i$ value of $3.7{\times}10^{-6}\;M$. Both compounds exhibited less inhibition of $\alpha$-secreatase (TACE) and other serine proteases including chymotrypsin, trypsin, and elastase, suggesting that they ere relatively specific and selective inhibitors to BACE1. Furthermore, both compounds significantly reduced the extracellular $A{\beta}$ secretion in $APP_{695}$-transfected B103 cells.

Characterization of a New Anti-dementia β-secretase Inhibitory Peptide from Arctoscopus japonicus

  • Park, Seul Bit Na;Kim, Sung Rae;Byun, Hee-Guk
    • Journal of Chitin and Chitosan
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    • v.23 no.4
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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.