• 생약학회지
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• 제54권1호
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• pp.9-15
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• 2023

In the previous study, we reported that cynaroside isolated from Lysimachia christinae methanolic extract had potent neuroprotective activities in neuronal cell death injured by excessive glutamate. In this study, we tried to confirm the neuroprotective activities of cynaroside in glutamate injured HT22 cells and establish mechanisms of neuroprotective action of cynaroside. We employed HT22 cells damaged by glutamate-induced cell death as a bioassay system. Cynaroside decreased reactive oxygen species increased by excessive glutamate treatment in HT22 cells. Also, Ca²⁺ concentration was decreased by cynaroside treatment. Cynaroside restored mitochondrial membrane potential to normal condition. It also increased not only glutathione reductase but also peroxidase to the control level. And it increased amount of glutathione, an endogenous antioxidant. These results suggested that cynaroside isolated from L. christinae showed potent neuroprotective activity through the anti-oxidative pathway.

• 생약학회지
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• 제52권3호
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• pp.149-156
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• 2021

Excessive glutamate can cause oxidative stress in neuronal cells and this can be the reason for neurodegenerative disease. In this study, we investigated the protective effect of Spirulina maxima hot ethanol extract on mouse hippocampal HT22 cell of which glutamate receptor has no function. HT22 cells were pre-treated with S. maxima sample at a dose dependent manner (1, 10 and 100 ㎍/ml). After an hour, glutamate was treated. Cell viability, reactive oxygen species (ROS) accumulation, Ca²⁺ influx, decrease of mitochondrial membrane potential level and glutathione related assays were followed by then. S. maxima ethanol extract improved the cell viability by suppressing the ROS and Ca²⁺ formation, retaining the mitochondrial membrane potential level and protecting the activity of the antioxidant enzymes compared with group of vehicle-treated controls. These suggest that S. maxima may decelerate the neurodegeneration by attenuating neuronal damage and oxidative stress.

• 동의신경정신과학회지
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• 제22권2호
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• pp.147-162
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• 2011

Objectives : This experiment was designed to investigate the effect of the BSGE hot water extract on serotonin biosynthesis of depression model. Methods : The cytotoxicity of the BSGE hot water extract was analyzed by MTT assay on P815 cell. The antioxidant activity was measured by DPPH free radical-scavenging activity and SOD activity on P815 cell. The quantity of 5-HT and expression of TPH-1, AAADC and MAOa mRNA was measured by of HPLC profle Analysis on P815 cell. Results : 1. The BSGE hot water extract increased DPPH free radical-scavenging activity and SOD activity on P815 cell. 2. The BSGE hot water extract increased significantly the quantity of 5-HT. 3. The BSGE hot water extract increased the expression of TPH-1 mRNA. Conclusions : This experiment shows that the BSGE hot water extract might be effective for the prevention and treatment of depression. Investigation into the clinical use of the BSGE hot water extract for depression is suggested for future research.

• 생약학회지
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• 제44권4호
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• pp.379-383
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• 2013

Portulaca oleracea L. is known to have many biological benefits such as anti-oxidant, anti-inflammatory, anti-allergic and anti-tumor. The objective of this study is to explore the neuroprotective effect of P. oleracea L. against glutamate-induced oxidative stress in mouse hippocampal HT22 cells. P. oleracea L. 70% ethanol extract and solvent fractions have the potent neroprotective effects on glutamate-induced nerotoxicity by induced the expression of heme oxygenase (HO)-1 in HT22 cells. Especially, ethyl acetate fraction showed higher protective effect. In HT22 cell, P. oleracea L. treatment with ERK inhibitor (PD98059) and c-JUN N-terminal kinase (JNK) inhibitor (SP600125) reduced P. oleracea L. ethyl acetate fraction induced HO-1 expression and P. oleracea L. ethyl acetate fraction also increased ERK and JNK phosphorylation. Furthermore, we found that treatment of P. oleracea L. caused the nuclear accumulation of Nrf2. In conclusion, the ethyl acetate fraction of 70% ethanol extract of P. oleracea L. significantly protect glutamate-induced oxidative damage by induction of HO-1 via Nrf2, ERK and JNK pathway in mouse hippocampal HT22. Taken together these finding suggest that P. oleracea L. ethyl acetate fraction is good source for taking active compounds and may be a potential therapeutic agent for brain disorder that induced by oxidative stress and neuronal damage.

• 생약학회지
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• 제38권3호통권150호
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• pp.287-290
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• 2007

Phytochemical investigation of the MeOH extract of the dried stem barks of Fraxinus rhynchophylla Hance (Oleaceae), as guided by cytoprotective activity against tert-butyl hydroperoxide (t-BHP)-induced cell injury in mouse hippocampal HT22 cells, furnished two coumarins, esculetin (1) and fraxetin (2). Compounds 1 and 2 had the significant cytoprotective effects on t-BHP-induced cellular oxidative injury in HT22 cells. Furthermore, compounds 1 and 2 showed potent DPPH radical scavenging effect, exhibiting $IC_{50}$ values of 14.68 and 9.64 ${\mu}M$, respectively.

• 문화기술의 융합
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• 제8권3호
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• pp.291-296
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• 2022

퇴행성 신경질환 치료를 위한 AChE inhibitor 관련 연구로써 생물학적 유용성을 높인 커큐민에 대한 연구를 수행하게 되었다. 본 연구의 목적은 아리큐민(강황추출물)에 대한 in vitro 신경보호 효과를 확인하는데 있다. 신경보호효과를 확인하기 위해 아리큐민(강황추출물)에 대한 AChE inhibition을 평가하였고, HT-22 세포에 대한 세포생존율을 분석하였으며, 산화스트레스(glutamate, H₂O₂) 유발에 따른 HT-22 세포생존을 확인하였다. 아리큐민(강황추출물)의 AChE 저해율 변화결과 아리큐민 39.06㎍/㎖ 이상의 농도에서 약 20% 이상의 AChE 활성을 저해하는 것으로 확인하였다. 그리고 산화스트레스(glutamate 5 mM 및 H₂O₂ 500 µM) 유발 HT-22 cell의 세포 독성을 0.01~0.1 mg/ml 농도에서부터 유의하게 억제하는 것을 확인하였다(p<0.05). 이와 같은 결과로 볼 때 아리큐민(강황추출물)은 신경보호 효과 효능이 우수한 것으로 확인되었다.

• 생명과학회지
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• 제22권1호
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• pp.55-61
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• 2012

Akt는 세포의 증식과 분화에 관여하며 많은 암종에서 과발현되어 있다는 것이 보고되었다. 본 연구에서는 Akt의 조절을 통한 셀레늄의 HT-29 세포의 세포증식억제 시너지효과를 확인하였다. 셀레늄을 농도별과 시간별로 처리하였을 때 HT-29 세포의 증식이 억제되었고, apoptosis가 일어남을 확인하였다. 셀레늄을 농도별로 처리하여 Western blotting 및 immunofluorescence를 실시한 결과 Akt의 인산화가 저해되었고 COX-2의 발현도 저해되었다. 또한 Akt 저해제인 LY294002를 처리한 결과, HT-29 대장암세포의 증식이 억제되었으며, LY294002를 셀레늄과 병행처리하였을 때 셀레늄에 의한 세포증식억제 효과가 더 강하게 나타나는 것을 확인하였다. Akt siRNA에 의한 Akt의 불활성화는 non-transfected 세포에 비하여 HT-29 세포의 성장을 더 강하게 억제하였으며, Akt가 불활성화 되었을 때 COX-2의 발현 역시 non-transfected 세포에 비하여 감소된 것을 확인하였다. 따라서 HT-29 세포에서 셀레늄의 세포증식억제 효과는 Akt와 COX-2 신호분자의 조절을 통해 일어나며, Akt 의 저해는 셀레늄의 대장암세포증식 억제에 시너지 효과를 나타냄을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.217-225
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• 2021

This study aimed to investigate the neuroprotective effects of 1-methoxylespeflorin G11 (MLG), a pterocarpan, against glutamate-induced neurotoxicity in neuronal HT22 hippocampal cells. The protective effects of MLG were evaluated using MTT assay and microscopic analysis. The extent of apoptosis was studied using flow cytometric analysis performed on the damaged cells probed with annexin V/propidium iodide. Moreover, mitochondrial reactive oxygen species (ROS) were assessed using flow cytometry through MitoSOXTM Red staining. To determine mitochondrial membrane potential, staining with tetramethylrhodamine and JC-1 was performed followed by flow cytometry. The results demonstrated that MLG attenuates glutamate-induced apoptosis in HT22 cells by inhibiting intracellular ROS generation and mitochondrial dysfunction. Additionally, MLG prevented glutamate-induced apoptotic pathway in HT22 cells through upregulation of Bcl-2 and downregulation of cleaved PARP-1, AIF, and phosphorylated MAPK cascades. In addition, MLG treatment induced HO-1 expression in HT22 cells. These results suggested that MLG exhibits neuroprotective effects against glutamate-induced neurotoxicity in neuronal HT22 cells by inhibiting oxidative stress and apoptosis.

• Natural Product Sciences
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• 제18권3호
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• pp.177-182
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• 2012

Oxidative stress potentially induces neurotoxicity which is believed to underlie several major age-related diseases of the central nervous system. This study sought to identify the cytoprotective effects of sixty-nine Cambodian plants against glutamate-induced cell death. Cultured HT22 cells were applied as an in vitro model, and neurotoxicity was induced in these neuronal cells by exposure to a determined concentration of glutamate. Sixty-nine plant sources, as Cambodia's indigenous species, were purchased from O'reusey Market, Phnom Penh, and extracted with ethanol. These extracts were screened for cytoprotective effects against glutamate-triggered neurotoxicity in HT22 cells at concentrations of 100 and 300 ${\mu}g/ml$. Of these, eight ethanol extracts, bark of Anacardium occidentale, bark and sapwood of Bauhinia pulla, flowers of Borassus flabellifer, stems and leaves of Coix lacryma-jobi, bark and sapwood of Diospyros nitida, sapwood of Dipterocarpus obtusifolius, stems of Oryza rufipogon, and fruits of Phyllanthus emblica, showed significant cytoprotective effects against glutamate-induced cell damage and degeneration in HT22 cells.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.250-257
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• 2023

Glutamate는 포유류의 중추신경계에 분포하는 흥분성 신경전달물질로, 기억, 인지, 그리고 학습 등에 있어서 중요한 역할을 한다. 하지만 고농도의 Glutamate는 신경세포에 독성을 유발하여 신경세포사멸을 유도함으로써 알츠하이머병, 파킨슨병, 뇌졸중 등의 신경퇴행성질환을 일으키는 것으로 알려져 있다. 본 연구에서 아열대 천연물의 항산화 활성과 신경보호 효과를 분석하였다. 11종의 아열대 추출물 중에서 Salacca wallichiana 추출물 (SE)의 라디칼 소거활성이 뛰어난 것으로 나타났다. 그리고 SE의 신경보호 효과를 조사한 결과 glutamate로 유도되는 cell death로부터 신경세포를 보호하였다. 또한 glutamate로 유도되는 apoptosis로부터 HT22 세포를 보호하는 효과는 Annexin V와 PI로 염색한 후 flow cytometry를 통해 분석되었다. 추가적으로 H₂DCFDA 염색을 이용하여 SE가 glutamate로 유도되는 세포 내 활성 산소 종 (ROS)을 억제한다는 것을 확인했다. SE의 신경보호 효과는 oxidative stress로 유발되는 Mitogen-activated protein kinase (MAPK) signaling pathway를 억제함으로써 신경세포를 보호하는 것으로 나타났다. 결과적으로 SE가 신경퇴행성질환을 예방하기 위한 치료제 개발에 기여할 수 있음을 나타낸다.