• Proceedings of the PSK Conference
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• 2000.10a
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• pp.170.2-171
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• 2000

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.150.2-151
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• 2000

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.5
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• pp.163-169
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• 2007

The neurotoxicity of amyloid $\beta(A\beta)$ is associated with an increased production of reactive oxygen species and apoptosis, and it has been implicated in the development of Alzheimer's disease. While(-)-epigallocatechin-3-gallate(EGCG) suppresses $A\beta$-induced apoptosis, the mechanisms underlying this process have yet to be completely clarified. This study was designed to investigate whether EGCG plays a neuroprotective role by activating cell survival system such as protein kinase C(PKC), extracellular-signal-related kinase(ERK), c-Jun N-terminal kinase(JNK), and anti-apoptotic and pro-apoptotic genes in SH-SY5Y human neuroblastoma cells. One ${\mu}M\;A{\beta}_{1-42}$ decreased cell viability, which was correlated with increased DNA fragmentation evidenced by DAPI staining. Pre-treatment of SH-SY5Y neuroblastoma cells with EGCG($1{\mu}M$) significantly attenuated $A{\beta}_{1-42}$-induced cytotoxicity. Potential cell signaling candidates involved in this neuroprotective effects were further examined. EGCG restored the reduced PKC, ERK, and JNK activities caused by $A{\beta}_{1-42}$ toxicity. In addition, gene expression analysis revealed that EGCG prevented both the $A{\beta}_{1-42}$-induced expression of a pro-apoptotic gene mRNA, Bad and Bax, and the decrease of an anti-apoptotic gene mRNA, Bcl-2 and Bcl-xl. These results suggest that the neuroprotective mechanism of EGCG against $A{\beta}_{1-42}$-induced apoptotic cell death includes stimulation of PKC, ERK, and JNK, and modulation of cell survival and death genes.

• The Korea Journal of Herbology
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• v.30 no.1
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• pp.67-75
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• 2015

Objectives : The aim of this study is to examine the neuroprotective effect of wheat bran extract (WBE) against ${\beta}$-amyloid ($A{\beta}$)-induced apoptotic cell death in SH-SY5Y human neuroblastoma cells and memory impairment in triple transgenic animal model's of Alzheimer's disease (3xTg AD mice). Methods : In SH-SY5Y cells, MTT assay and TUNEL staining were conducted to evaluate the protective effect of WBE against $A{\beta}_{25-35}$-induced neurotoxicity and apoptosis. Alterations in mitochondrial transmembrane potential (MMP), expression of proapoptotic Bax and antiapoptotic Bcl-2 proteins, cleavage of PARP, and brain-derived neurotrophic factor (BDNF) levels were analyzed to elucidate the neuroprotective mechanism of WBE. To further investigate the memory enhancing effect of WBE, Morris water maze test was performed in 3xTg AD mice. Results : In SH-SY5Y cells, WBE protected against $A{\beta}_{25-35}$-caused cytotoxicity and apoptosis as shown by the restoration of cell viability in MTT assay and inhibition of DNA fragmentation in TUNEL staining. $A{\beta}_{25-35}$-induced apoptotic signals such as dissipation of MMP, decreased Bcl-2/Bax ratio, and cleavage of PARP were suppressed by WBE. Moreover, WBE up-regulated the protein levels of BDNF, which seemed to be mediated by activation of cAMP response element-binding protein (CREB). In 3xTg AD mice, oral administration of WBE attenuated learning and memory deficit as verified by reduced mean escape latency in water maze test. Conclusions : WBE protects neuronal cells from $A{\beta}_{25-35}$-induced apoptotic cell death and restores learning and memory impairments in 3xTg AD mice. These findings suggest that WBE exhibit neuroprotective potential for the management of AD.

• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.912-919
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• 2020

Hardy kiwifruits (Actinidia arguta Planch.) have high amounts of antioxidants, including ascorbic acid (vitamin C) and phenolics. The anti-cholinesterase activity and neuroprotective effects of three different cultivars of hardy kiwifruits, cv. Mansu (A. arguta × A. deliciosa), cv. Haeyeon (A. arguta), and cv. Chiak (A. arguta), on PC-12 and SH-SY5Y cells were evaluated. Extraction of phenolics and vitamin C was carried out using 80% (v/v) aqueous ethanol and metaphosphoric acid assisted with homogenization, respectively. Hardy kiwifruit of cv. Mansu showed higher total phenolic, total flavonoid, and vitamin C contents and antioxidant capacity compared to the other two cultivars of hardy kiwifruits, cv. Haeyeon and cv. Chiak. Analysis of high-performance liquid chromatography results revealed the presence of procyanidin B2, (-)-epicatechin, neochlorogenic acid, cryptochlorogenic acid, rutin, hyperoside, isoquercitrin, and astragalin in hardy kiwifruits. The three cultivars of hardy kiwifruits had a wide range of vitamin C content of 55.2-130.0 mg/100 g fresh weight. All three cultivars of hardy kiwifruits had protective effects on neuronal PC-12 and SH-SY5Y cells exposed to hydrogen peroxide by increasing cell viability and reducing intracellular oxidative stress. Furthermore, the hardy kiwifruits inhibited acetylcholinesterase and butyrylcholinesterase. Collectively, these results suggest that hardy kiwifruits rich in antioxidants like phenolics and vitamin C have good potential as functional materials in neuroprotective applications.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.195-200
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• 2009

Zinc released from excited glutamatergic neurons accelerates amyloid ${\beta}$ (A ${\beta}$) aggregation, underscoring the therapeutic potential of zinc chelation for the treatment of Alzheimer's disease (AD). Zinc can also alter A ${\beta}$ concentration by affecting its degradation. In order to elucidate the possible role of zinc influx in secretase-processed A ${\beta}$ production, SH-SY5Y cells stably expressing amyloid precursor protein (APP) were treated with pyrrolidine dithiocarbamate (PDTC), a zinc ionophore, and the resultant changes in APP processing were examined. PDTC decreased A ${\beta}$ 40 and A ${\beta}$ 42 concentrations in culture media bathing APP-expressing SH-SY5Y cells. Measuring the levels of a series of C-terminal APP fragments generated by enzymatic cutting at different APP-cleavage sites showed that both ${\beta}$-and ${\alpha}$-cleavage of APP were inhibited by zinc influx. PDTC also interfered with the maturation of APP. PDTC, however, paradoxically increased the intracellular levels of A ${\beta}$ 40. These results indicate that inhibition of secretase-mediated APP cleavage accounts -at least in part- for zinc inhibition of A ${\beta}$ secretion.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.195-200
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• 2011

Neuronal cell death is a common characteristic feature of a variety of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. However, there have been no effective drugs to successfully prevent neuronal death in those diseases. In the present study, docosyl cafferate (DC), a derivative of caffeic acid, was isolated from Rhus verniciflua and its protective effects on tBHP-induced neuronal cell death were examined in SH-SY5Y human neuroblastoma cells. Pretreatment of DC significantly attenuated tBHP-induced neuronal cell death in a concentration-dependent manner. DC also significantly suppressed tBHP-induced caspase-3 activation. In addition, DC restored tBHP-induced depletion of intracellular Bcl-2, an anti-apoptotic member of the Bcl-2 family. Furthermore, DC significantly suppressed tBHP-induced degradation of IKB, which retains $NF-{\kappa}B$ in the cytoplasm, resulting in the suppression of nuclear translocation of $NF-{\kappa}B$ and its subsequent activation. Taken together, the results clearly demonstrate that DC exerts its neuroprotective activity against tBHP-induced oxidative stress through the suppression of nuclear translocation of $NF-{\kappa}B$.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1094-1104
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• 2018

The peel of astringent persimmon (Diospyros kaki Thunb. cv. Cheongdo-Bansi) is a by-product of dried persimmon (gotgam). We investigated if deastringent peel extracts of persimmon cv. Cheongdo-Bansi had antioxidative and neuroprotective properties. Two different extracts were prepared: thermally and nonthermally treated persimmon peel extracts (TPE and NTPE, respectively). Both TPE and NTPE were fractionated sequentially in n-hexane, chloroform, ethyl acetate, n-butanol, and water. The TPE and NTPE ethyl acetate fractions had the highest total phenolic and flavonoid contents as well as antioxidant capacities among all the fractions. Pretreatment of neuronal PC-12 and SH-SY5Y cells with the TPE and NTPE ethyl acetate fractions increased cell viability after exposure to oxidative stress. The ethyl acetate fraction of TPE attenuated oxidative stress inside both PC-12 and SH-SY5Y cells more effectively than that of NTPE. Furthermore, the TPE and NTPE ethyl acetate fractions inhibited acetylcholinesterase and butyrylcholinesterase. Analysis of ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry results revealed gallic acid, kaempferol, kaempferol-3-O-galactoside, kaempferol-3-O-glucoside, quercetin, quercetin3-O-galactoside, quercetin-3-O-galactoside-2'-O-gallate, and quercetin-3-O-glucoside as the major phenolics of the TPE and NTPE ethyl acetate fractions. Taken together, these results suggest that the ethyl acetate fraction of deastringent persimmon peel is rich in antioxidants and has potential as a functional food to reduce oxidative stress.

• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.118-125
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• 2011

Free radical scavenging and antioxidants have attracted attention as a way to prevent the progression of Parkinson's disease (PD). This study was carried out to investigate the effects of n-hexane fraction from Laurus nobilis L. (Lauraceae) leaves (HFL) on dopamine (DA)-induced intracellular reactive oxygen species (ROS) production and apoptosis in human neuroblastoma SH-SY5Y cells. Compared with apomorphine (APO, $IC_{50}=18.1\;{\mu}M$) as a positive control, the HFL $IC_{50}$ value for DA-induced apoptosis was $3.0\;{\mu}g/ml$, and two major compounds from HFL, costunolide and dehydrocostus lactone, were $7.3\;{\mu}M$ and $3.6\;{\mu}M$, respectively. HFL and these major compounds significantly inhibited ROS generation in DA-induced SH-SY5Y cells. A rodent 6-hydroxydopamine (6-OHDA) model of PD was employed to investigate the potential neuroprotective effects of HFL in vivo. 6-OHDA was injected into the substantia nigra of young adult rats and an immunohistochemical analysis was conducted to quantitate the tyrosine hydroxylase (TH)-positive neurons. HFL significantly inhibited 6-OHDA-induced TH-positive cell loss in the substantia nigra and also reduced DA induced $\alpha$-synuclein (SYN) formation in SH-SY5Y cells. These results indicate that HFL may have neuroprotective effects against DA-induced in vitro and in vivo models of PD.

• The Korea Journal of Herbology
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• v.23 no.3
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• pp.53-60
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• 2008

Objectives : Oxidative stress has a critical role in neurodegenerative diseases. In this study, we investigated the antioxidant and neuroprotective effects of the ethanolic extract of Banryong-hwan (BRHE) in SH-SY5Y cells and primary rat mesencephalic dopaminergic neurons. Methods : To assess the antioxidant effects, we carried out 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)(ABTS) radical cation decolorization assay, and determination of total polyphenolic content. We evaluated the effect of BRHE treatment on neuroprotection against 6-hydroxydopamine(6-OHDA) toxicity using thiazolyl blue tetrazolium bromide(MTT) assay, nitric oxide(NO) assay, reactive oxygen species(ROS) assay in SH-SY5Y cells and tyrosine hydroxylase(TH) immunocytochemistry in primary rat mesencephalic dopaminergic neurons. Results : BRHE showed IC50 values of 328.10 ${\mu}g/mL$ and 43.12 ${\mu}g/mL$ in DPPH assay and in ABTS assay, respectively. Total polyphenolic content was 180.76 ${\mu}g/mL$. In SH-SY5Y cells, BRHE significantly attenuated the toxicity induced by 6-OHDA at the concentrations of 25-100 ${\mu}g/mL$ pre- and post- treatment in MTT assay. While 6-OHDA increased the NO and ROS contents, BRHE decreased them in a dose dependent manner. Moreover, in primary dopaminergic neuron culture, BRHE significantly protect-ed the dopaminergic cell loss against 6-OHDA toxicity up to 136% at the concentration of 75 ${\mu}g/mL$. Conclusions : These results demonstrate that BRHE has neuroprotective effect against 6-OHDA induced neurotoxicity through decreasing NO and ROS generation.