• BMB Reports
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• 제49권11호
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• pp.617-622
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• 2016

Oxidative stress is closely associated with various diseases and is considered to be a major factor in ischemia. NAD(P)H: quinone oxidoreductase 1 (NQO1) protein is a known antioxidant protein that plays a protective role in various cells against oxidative stress. We therefore investigated the effects of cell permeable Tat-NQO1 protein on hippocampal HT-22 cells, and in an animal ischemia model. The Tat-NQO1 protein transduced into HT-22 cells, and significantly inhibited against hydrogen peroxide ($H_2O_2$)-induced cell death and cellular toxicities. Tat-NQO1 protein inhibited the Akt and mitogen activated protein kinases (MAPK) activation as well as caspase-3 expression levels, in $H_2O_2$ exposed HT-22 cells. Moreover, Tat-NQO1 protein transduced into the CA1 region of the hippocampus of the animal brain and drastically protected against ischemic injury. Our results indicate that Tat-NQO1 protein exerts protection against neuronal cell death induced by oxidative stress, suggesting that Tat-NQO1 protein may potentially provide a therapeutic agent for neuronal diseases.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.185.1-185.1
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• 2003

In this study, we investigated the effect of cadmium on genes expression related to zinc homeostasis in HT22 hippocampal neuron cell line by RT -PCR and western blotting technics. In the time-course effect, cadmium up-regulated the relative levels of MT -I and MT -II to~b-actin at 4 hr after treatment. These effects were consistent with MT -I/II protein contents by western blot analysis. But MT -III, a specific MT isoform in brain, was not affected by cadmium. (omitted)

• BMB Reports
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• 제53권11호
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• pp.582-587
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• 2020

It is well known that oxidative stress participates in neuronal cell death caused production of reactive oxygen species (ROS). The increased ROS is a major contributor to the development of ischemic injury. Indoleamine 2,3-dioxygenase 1 (IDO-1) is involved in the kynurenine pathway in tryptophan metabolism and plays a role as an anti-oxidant. However, whether IDO-1 would inhibit hippocampal cell death is poorly known. Therefore, we explored the effects of cell permeable Tat-IDO-1 protein against oxidative stress-induced HT-22 cells and in a cerebral ischemia/reperfusion injury model. Transduced Tat-IDO-1 reduced cell death, ROS production, and DNA fragmentation and inhibited mitogen-activated protein kinases (MAPKs) activation in H₂O₂ exposed HT-22 cells. In the cerebral ischemia/reperfusion injury model, Tat-IDO-1 transduced into the brain and passing by means of the blood-brain barrier (BBB) significantly prevented hippocampal neuronal cell death. These results suggest that Tat-IDO-1 may present an alternative strategy to improve from the ischemic injury.

• Journal of Ginseng Research
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• 제43권2호
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• pp.326-334
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• 2019

Background: The objective of our study was to analyze the neuroprotective effects of ginsenoside derivatives Rb1, Rb2, Rc, Rd, Rg1, and Rg3 against glutamate-mediated neurotoxicity in HT22 hippocampal mouse neuron cells. Methods: The neuroprotective effect of ginsenosides were evaluated by measuring cell viability. Protein expressions of mitogen-activated protein kinase (MAPK), Bcl2, Bax, and apoptosis-inducing factor (AIF) were determined by Western blot analysis. The occurrence of apoptotic and death cells was determined by flow cytometry. Cellular level of $Ca^{2+}$ and reactive oxygen species (ROS) levels were evaluated by image analysis using the fluorescent probes Fluor-3 and 2',7'-dichlorodihydrofluorescein diacetate, respectively. In vivo efficacy of neuroprotection was evaluated using the Mongolian gerbil of ischemic brain injury model. Result: Reduction of cell viability by glutamate (5 mM) was significantly suppressed by treatment with ginsenoside Rb2. Phosphorylation of MAPKs, Bax, and nuclear AIF was gradually increased by treatment with 5 mM of glutamate and decreased by co-treatment with Rb2. The occurrence of apoptotic cells was decreased by treatment with Rb2 ($25.7{\mu}M$). Cellular $Ca^{2+}$ and ROS levels were decreased in the presence of Rb2, and in vivo data indicated that Rb2 treatment (10 mg/kg) significantly diminished the number of degenerated neurons. Conclusion: Our results suggest that Rb2 possesses neuroprotective properties that suppress glutamate-induced neurotoxicity. The molecular mechanism of Rb2 is by suppressing the MAPKs activity and AIF translocation.

• Journal of Ginseng Research
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• 제47권3호
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• pp.390-399
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• 2023

Background: Gintonin (GT), a Panax ginseng-derived lysophosphatidic acid receptor (LPAR) ligand, has positive effects in cultured or animal models for Parkinson's disease, Huntington's disease, and so on. However, the potential therapeutic value of GT in treating epilepsy has not yet been reported. Methods: Effects of GT on epileptic seizure (seizure) in kainic acid [KA, 55mg/kg, intraperitoneal (i.p.)]-induced model of mice, excitotoxic (hippocampal) cell death in KA [0.2 ㎍, intracerebroventricular (i.c.v.)]-induced model of mice, and levels of proinflammatory mediators in lipopolysaccharide (LPS)-induced BV2 cells were investigated. Results: An i.p. injection of KA into mice produced typical seizure. However, it was significantly alleviated by oral administration of GT in a dose-dependent manner. An i.c.v. injection of KA produced typical hippocampal cell death, whereas it was significantly ameliorated by administration of GT, which was related to reduced levels of neuroglial (microglia and astrocyte) activation and proinflammatory cytokines/enzymes expression as well as increased level of the Nrf2-antioxidant response via the upregulation of LPAR 1/3 in the hippocampus. However, these positive effects of GT were neutralized by an i.p. injection of Ki16425, an antagonist of LPA1-3. GT also reduced protein expression level of inducible nitric-oxide synthase, a representative proinflammatory enzyme, in LPS-induced BV2 cells. Treatment with conditioned medium clearly reduced cultured HT-22 cell death. Conclusion: Taken together, these results suggest that GT may suppress KA-induced seizures and excitotoxic events in the hippocampus through its anti-inflammatory and antioxidant activities by activating LPA signaling. Thus, GT has a therapeutic potential to treat epilepsy.

• 약학회지
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• 제55권4호
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• pp.319-323
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• 2011

Curcumin, of which a critical characteristic is the capacity of crossing the blood-brain barrier, has been reported to induce the expression of neuroprotective heme oxygenase (HO)-1. The aim of this study is to compare HO-1-inducing capacity and neuroprotective activity of curcumin, its demethoxy (demethoxycurcumin, DMC; bis-demethoxycurcumin, BDMC) and hydrogenated derivatives (tetrahydrocurcumin, THC) in mouse hippocampal HT22 cells. Curcumin attenuated glutamate-induced cell death through HO-1 expression. DMC lacking a methoxy group on one of the aromatic rings possessed slightly lower activity in HO-1 expression and neuroprotection than curcumin. Similarly, BDMC, which lacks two methoxy groups on both of the aromatic rings, showed less activity than curcumin. These findings suggest that the presence of methoxy groups on the aromatic ring is required to enhance neuroprotective HO-1 expression. The reduction of the diarylheptadienone chain of curcumin by hydrogen, as in THC, was accompanied by a complete loss of ability to induce HO-1 expression and neuroprotection, suggesting that the conjugated double bonds of the central seven-carbon chain of curcumin may be essential for its ability to induce neuroprotective HO-1 expression. Our findings may provide useful information for further development of neuroprotective HO-1 inducers.

• Journal of Ginseng Research
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• 제45권1호
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• pp.108-118
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• 2021

Background: Korean ginseng (Panax ginseng Meyer) contains a variety of ginsenosides that can be metabolized to a biologically active substance, compound K. Previous research showed that compound K could be enriched in the red ginseng extract (RGE) after hydrolysis by pectinase. The current study investigated whether the enzymatically hydrolyzed red ginseng extract (HRGE) containing a notable level of compound K has cognitive improving and neuroprotective effects. Methods: A scopolamine-induced hypomnesic mouse model was subjected to behavioral tasks, such as the Y-maze, passive avoidance, and the Morris water maze tests. After sacrificing the mice, the brains were collected, histologically examined (hematoxylin and eosin staining), and the expressions of antioxidant proteins analyzed by western blot. Results: Behavioral assessment indicated that the oral administration of HRGE at a dosage of 300 mg/kg body weight reversed scopolamine-induced learning and memory deficits. Histological examination demonstrated that the hippocampal damage observed in scopolamine-treated mouse brains was reduced by HRGE administration. In addition, HRGE administration increased the expression of nuclear-factor-E2-related factor 2 and its downstream antioxidant enzymes NAD(P)H:quinone oxidoreductase and heme oxygenase-1 in hippocampal tissue homogenates. An in vitro assay using HT22 mouse hippocampal neuronal cells demonstrated that HRGE treatment attenuated glutamate-induced cytotoxicity by decreasing the intracellular levels of reactive oxygen species. Conclusion: These findings suggest that HRGE administration can effectively alleviate hippocampus-mediated cognitive impairment, possibly through cytoprotective mechanisms, preventing oxidative-stress-induced neuronal cell death via the upregulation of phase 2 antioxidant molecules.

• 한국식품과학회지
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• 제50권5호
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• pp.543-548
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• 2018

본 연구는 꾸지뽕 열매 조다당류 분획물(CTP)의 산화방지 활성 및 신경세포 보호 효과에 관하여 알아보기 위하여, 항산화 활성인 라디칼 제거능 및 환원력을 평가한 결과, 꾸지뽕 열매 조다당류의 농도가 증가할수록 산화방지 활성이 유의적으로 증가하는 것으로 나타났다. 또한, 이러한 꾸지뽕 열매 조다당류의 뇌신경세포 보호 효과에 관하여 알아보기 위하여 생쥐의 해마 유래 뇌신경세포에 꾸지뽕 열매 조다당류를 처리한 후 과산화수소로 산화적인 스트레스를 유도하여 세포 독성에 관하여 알아본 결과, 꾸지뽕 열매 조다당류의 처리는 농도 의존적으로 뇌신경 세포의 생존율을 증가시켰으며, 이에 따라 산화방지 효소인 SOD 활성이 증가하고 지방질 과산화 생성물인 MDA level이 감소한 것을 알 수 있었다. 이상의 결과들로 꾸지뽕 열매 조다당류의 산화방지 활성 및 뇌신경세포 보호 효과에 관하여 확인할 수 있었으며, 추후 어떤 메커니즘으로 신경세포를 보호하는지 추가적인 연구가 필요할 것으로 생각한다. 꾸지뽕 열매 조다당류 분획물은 산화방지 및 산화적 스트레스로부터 신경세포 보호효과를 나타내어 퇴행성 신경질환 예방에 유용한 건강기능성 식품 소재가 될 것으로 사료된다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2006년도 Spring Conference
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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.

• 한국식품과학회지
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• 제52권1호
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• pp.60-66
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• 2020

본 연구는 DCE의 항산화 활성 및 신경세포 보호 효과에 평가하였다. 감 심지로부터 유용성 성분을 얻기 위하여 에탄올 추출을 한 결과 약 10.36±1.34%의 추출물의 수율을 얻을 수 있었다. DCE의 총 폴리페놀, 총 폴라보노이드 함량과 항산화 활성으로 DPPH, ABTS 라디칼 소거능 및 환원력을 평가한 결과, DCE의 항산화 활성이 농도 의존적으로 증가하는 것으로 나타났다. 또한, DCE의 HT22 세포 보호 효과에 관하여 알아보기 위하여 HT22 세포에 DCE을 처리한 후 H₂O₂를 통한 산화적인 스트레스의 유도를 통하여 세포독성에 미치는 영향을 확인한 결과, DCE의 처리는 HT22 세포에 독성이 나타나지 않았으며, 이에 따라 항산화 효소인 SOD 활성이 증가와 지질과산화 생성물인 MDA level의 감소를 확인 할 수 있었다. 이러한 결과들로 볼 때, DCE의 항산화 및 산화적 스트레스로부터 신경세포 보호효과를 확인함으로서 향후 퇴행성 신경질환 예방에 유용한 건강기능성 식품 소재로서의 개발 가능성이 높을 것으로 판단된다.