• Title/Summary/Keyword: Brain Hippocampus

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Inhibitory Effect of Bee Venom on Lipopolysaccharide-induced Memorial Impairment and Acetylcholine Esterase, Secretase Activity

  • Kwon, Dae-Hyun;Song, Ho-Sueb
    • Journal of Acupuncture Research
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    • v.23 no.2
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    • pp.33-46
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    • 2006
  • Alzheimer's disease (AD) is the most prevalent form of neurodegenerative disease associated with aging in the human population. This disease is characterized by the extracellular deposition of beta-amyloid peptide $(A{\beta})$ in cerebral plaques. $A{\beta}$ is derived from the ${\beta}-amyloid$ precursor protein (APP) by the enzymes, ${\beta}-$ and ${\eta}o-secretase$. Compounds that ${\beta}-$ or ${\eta}o-secretase$ inhibit activity, can reduce the production of $A{\beta}$ peptides, and thus have therapeutic potential in the treatment of AD. Increasing body of evidence has been demonstrated that Bee Venom(BV) Acupuncture could compete with complex protein involving in multiple step of $NF-{\kappa}B$ activation and exert the anti-inflammatory potential of combined inhibition of the prostanoid and nitric oxide synthesis systems by inhibition of IKK and $NF-{\kappa}B$. In this study, I investigated possible effects of BV on memory dysfunction caused by lipopolysaccharide (LPS) and $A{\beta}$ through inhibition of secretases activities and $A{\beta}$ aggregation. I examined the improving effect of BV on the LPS (2.5 mg/Kg, i.p.)-induced memory dysfunction using passive avoidance response and water maze tests in the mice. BV (0.84, $1.67\;{\mu}g/ml$) reversed the LPS-induced memorial dysfunction in dose dependent manner. BV also dose-dependently attenuated LPS-induced ${\beta}$ and ${\eta}o-secretase$ activities in cerebral cortex and hippocampus of the mice brain. This study therefore suggests that BV acupuncture method may be useful for prevention of development or progression of AD.

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Neuroprotective effects of the antioxidant action of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride against ischemic neuronal damage in the brain

  • Ha, Seung Cheol;Han, A Reum;Kim, Dae Won;Kim, Eun-A;Kim, Duk-Soo;Choi, Soo Young;Cho, Sung-Woo
    • BMB Reports
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    • v.46 no.7
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    • pp.370-375
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    • 2013
  • Ischemia is characterized by oxidative stress and changes in the antioxidant defense system. Our recent in vitro study showed that 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride protects cortical astrocytes against oxidative stress. In the current study, we examined the effects of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride on ischemia-induced neuronal damage in a gerbil ischemia/reperfusion models. Extensive neuronal death in the hippocampal CA1 area was observed 4 days after ischemia/reperfusion. Intraperitoneal injection of 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride (0.3 mg/kg body weight) significantly prevented neuronal death in the CA1 region of the hippocampus in response to transient forebrain ischemia. 2-Cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride administration reduced ischemia-induced increases in reactive oxygen species levels and malondialdehyde content. It also attenuated the associated reductions in glutathione level and superoxide dismutase, catalase, and glutathione peroxidase activities. Taken together, our results suggest that 2-cyclopropylimino-3-methyl-1,3-thiazoline hydrochloride protects against ischemia-induced neuronal damage by reducing oxidative stress through its antioxidant actions.

Ginsenoside Rg1 modulates medial prefrontal cortical firing and suppresses the hippocampo-medial prefrontal cortical long-term potentiation

  • Ghaeminia, Mehdy;Rajkumar, Ramamoorthy;Koh, Hwee-Ling;Dawe, Gavin S.;Tan, Chay Hoon
    • Journal of Ginseng Research
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    • v.42 no.3
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    • pp.298-303
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    • 2018
  • Background: Panax ginseng is one of the most commonly used medicinal herbs worldwide for a variety of therapeutic properties including neurocognitive effects. Ginsenoside Rg1 is one of the most abundant active chemical constituents of this herb with known neuroprotective, anxiolytic, and cognition improving effects. Methods: We investigated the effects of Rg1 on the medial prefrontal cortex (mPFC), a key brain region involved in cognition, information processing, working memory, and decision making. In this study, the effects of systemic administration of Rg1 (1 mg/kg, 3 mg/kg, or 10 mg/kg) on (1) spontaneous firing of the medial prefrontal cortical neurons and (2) long-term potentiation (LTP) in the hippocampal-medial prefrontal cortical (HP-mPFC) pathway were investigated in male Sprague-Dawley rats. Results: The spontaneous neuronal activity of approximately 50% the recorded pyramidal cells in the mPFC was suppressed by Rg1. In addition, Rg1 attenuated LTP in the HP-mPFC pathway. These effects were not dose-dependent. Conclusion: This report suggests that acute treatment of Rg1 impairs LTP in the HP-mPFC pathway, perhaps by suppressing the firing of a subset of mPFC neurons that may contribute to the neurocognitive effects of Rg1.

Gintonin stimulates autophagic flux in primary cortical astrocytes

  • Rahman, Md. Ataur;Hwang, Hongik;Nah, Seung-Yeol;Rhim, Hyewhon
    • Journal of Ginseng Research
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    • v.44 no.1
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    • pp.67-78
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    • 2020
  • Background: Gintonin (GT), a novel ginseng-derived exogenous ligand of lysophosphatidic acid (LPA) receptors, has been shown to induce cell proliferation and migration in the hippocampus, regulate calcium-dependent ion channels in the astrocytes, and reduce β-amyloid plaque in the brain. However, whether GT influences autophagy in cortical astrocytes is not yet investigated. Methods: We examined the effect of GT on autophagy in primary cortical astrocytes using immunoblot and immunocytochemistry assays. Suppression of specific proteins was performed via siRNA. LC3 puncta was determined using confocal microscopy. Results: GT strongly upregulated autophagy marker LC3 by a concentration- as well as time-dependent manner via G protein-coupled LPA receptors. GT-induced autophagy was further confirmed by the formation of LC3 puncta. Interestingly, on pretreatment with an mammalian target of rapamycin (mTOR) inhibitor, rapamycin, GT further enhanced LC3-II and LC3 puncta expression. However, GT-induced autophagy was significantly attenuated by inhibition of autophagy by 3-methyladenine and knockdown Beclin-1, Atg5, and Atg7 gene expression. Importantly, when pretreated with a lysosomotropic agent, E-64d/peps A or bafilomycin A1, GT significantly increased the levels of LC3-II along with the formation of LC3 puncta. In addition, GT treatment enhanced autophagic flux, which led to an increase in lysosome-associated membrane protein 1 and degradation of ubiquitinated p62/SQSTM1. Conclusion: GT induces autophagy via mTOR-mediated pathway and elevates autophagic flux. This study demonstrates that GT can be used as an autophagy-inducing agent in cortical astrocytes.

The Effect of Glucose Deprivation on the Oxygen Deprivation-induced Changes of [[$^3H$]-5-hydroxytryptamine Release in Rat Hippocampal Slices (흰쥐 해마 절편에서 산소고갈에 의한 [$^3H$-5-hydroxytryptamine 유리변동에 미치는 포도당고갈의 영향)

  • 이경은
    • Toxicological Research
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    • v.14 no.4
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    • pp.483-488
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    • 1998
  • During cerebral ischemia two important factors such as hypoxia and reduction of glucose can act as modulating stressor affecting the release of amine neurotransmitters including 5-hydroxytryptamine (5-HT). This study was performed to investigate the effect of glucose deprivation on the oxygen deprivation-induced changes of [3H]-5-HT release in the rat hippocampal slices. Experimental groups were divided into 4 groups for this study: normoxic/normoglycemic group, oxygen-deprived group, glucose-deprived group, and oxygen/glucose-deprived group. The hippocampus of rat brain was sliced by 400 $\mu\textrm{m}$ thickness with manual chopper. After 30 minutes preincubation in the normal buffer, the slices were incubated for 20 min in buffer containing [3H]-5-HT (0.1 M, 74 $\mu\textrm$Ci) for uptake. To measure the release of [3H]-5-HT into the buffer, the incubation medium was drained of and refilled with fresh buffer every ten minutes through a sequence of 14 tubes. Oxygen deprivation by gassing with 95% $N_2$/5% $CO_2$ and/or glucose deprivation was done in the 6th and 7th tube. The radioactivities in each buffer and the tissue were counted using scintillation counter. The results were expressed as fractional release. When slices were exposed to oxygen-deprived media for 20 min, the diminution followed by the rebound release of [3H]-5-HT was observed during the post-oxygen deprived period. However, glucose deprivation or oxygen/glucose deprivation markedly increased the release of [3H]-5-HT. which was opposite to the pattern observed in oxygen-deprived group. These results suggested that oxygen deprivation itself inhibits [3H]-5-HT release in rat hippocampal slices during oxygen-deprived period, but additional glucose deprivation convert the inhibitory response to increase of [3H]-5-HT release.

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Effects of Ginsenoside $Rg_1$ on Neural Progenitors Proliferation in Vitro and in Vivo

  • Shen Li-Hong
    • Proceedings of the Ginseng society Conference
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    • 2002.10a
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    • pp.522-530
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    • 2002
  • We have already known, neural progenitor cells exist not only in the developing brain, but in certain spots in adult CNS in mammals, so it will be of great value to find out some compounds which can interfere these cells proliferation ability. In this research, we observed that ginsenoside $Rg_1$ can not only enhance neural progenitors' proliferation ability in vitro, but increase neurogenesis in adult mouse dentate gyrus in vivo. Firstly, we set up neural progenitor cells' culture system from embryonic rats' hippocampus and prove their feature through immunocytochemistry. Then by using MTT assay, we found that when growing with ginsenoside $Rg_1(0.5\~2.5{\mu}mol/l)$, the progenitor cells' survival rate nearly doubled, furthermore, we proved that this increase was due to the increment of cell proliferation through $^3H-thimidine$ incorporation assay, hence, we drew the first conclusion: ginsenoside Rg1 has the ability to stimulate neural progenitor cells' proliferation in vitro; in order to observe this compound's effect in vivo, we devised the following experiment: after administering ginsenoside Rg1 (5, 10 mg/kg, once a day) intraperitoneally for two weeks, we examine the number of BrdU positive cells in the dentate gyrus of mice, and found that Rg1 could increase the number of proliferation cells significantly in vivo. From these studies, we are quite sure about Rg1's effects on the proliferation ability of neural progenitor cells both in vitro and in vivo, certain targets of the compound and its underlying mechanisms are in progress.

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Effect of a Sargassum serratifolium Extract on Neuroinflammation Induced by Lipopolysaccharides in Mice (LPS로 유도한 마우스의 급성신경염증에 대한 톱니모자반(Sargassum serratifolium) 추출물의 효과)

  • Choi, Min-Woo;Kim, Hyeung-Rak;Lee, Hyoung-Gon;Kim, Jae-Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.1
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    • pp.81-86
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    • 2019
  • The common hallmark of several neurodegenerative disorders, including Alzheimer's disease (AD), is the presence of chronic neuroinflammation, which contributes to the loss of neuronal structure and function. This study investigated the effects of an ethanolic extract of Sargassum serratifolium (SSE) in a lipopolysaccharides (LPS)-induced murine neuroinflammation model. Mice were administered SSE (100 mg/kg body weight) or vehicle for 5 days by oral gavage, and then treated with LPS or saline by intraperitoneal injection. Thereafter, the brain tissues were collected, and the expression of pro-inflammatory cytokines was analyzed by quantitative real-time RT-PCR. There was a marked increase in the spleen weight index in the LPS-treated groups, which indicated the induction of acute systemic inflammation. Based on significant increases in the levels of IL-1 and IL-6 expression, the induction of neuroinflammation was also evident in the cortex and hippocampus of the LPS-treated groups. The overall expression of IL-1 and IL-6 was decreased slightly by SSE administration, compared with the LPS group, and a marked change in IL-1 was observed in the cortex of the SSE-treated (SSE/LPS) group. These results suggest that SSE has potential as an anti-neuroinflammatory nutraceutical.

A Review on the Pain and Depression Comorbidity Animal Models (통증과 우울증의 병합 동물모델에 대한 최신 연구 동향 분석)

  • Song, Ji-Hye;Kook, Hye-Jung;Park, Byung-Jin;Kim, Song-Yi;Park, Ji-Yeun
    • Korean Journal of Acupuncture
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    • v.38 no.2
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    • pp.75-99
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    • 2021
  • Objectives : The purpose of this study is to analyze animal behavioral changes and related neurobiological mechanisms in recent studies using animal models with pain and depression. Methods : We conducted database search in Pubmed, NDSL, and EMBASE up to January 2021. Included studies were classified as depression-like behavior observed in pain model, pain-like behavior observed in depression model, and pain and depression comorbidity model. The results of pain- and depression-like behaviors, the changes of neurobiological mechanisms, and the treatment methods such as drugs, natural substance-derived chemicals, or acupuncture were analyzed. Results : We included 124 studies (81 studies in depression-like behavior observed in pain model, 19 studies in pain-like behavior observed in depression model, and 24 studies in pain and depression comorbidity model). Pain and depression comorbidity animal models were induced using various methods by drugs or surgery. Von frey test, a method for evaluating mechanical allodynia was the most commonly used for measuring pain-like behavior and the forced swimming test was the most commonly used for measuring depression-likes behavior. The changes of neurobiological factors, such as decrease of 5-hydroxytryptamine and increase of oxidative stress and pro-inflammation cytokines were generally changed in the frontal cortex, hippocampus, thalamus, and spinal cord in all types of models. For treating pain and depression-like behaviors, various types of drugs such as antidepressant, tranquilizer, analgesic, and natural substance-derived chemicals were used. Acupuncture treatment was used in 4 studies. Conclusions : In the future, more diverse studies on the combined model of pain and depression need to be conducted. In addition, it is necessary to establish a mechanistic basis for the development of various treatments by identifying the common mechanisms of pain and depression.

Anxiolytic effect of Korean Red Ginseng through upregulation of serotonin and GABA transmission and BDNF expression in immobilized mice

  • Bui, Bich Phuong;Nguyen, Phuong Linh;Do, Ha Thi Thu;Cho, Jungsook
    • Journal of Ginseng Research
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    • v.46 no.6
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    • pp.819-829
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    • 2022
  • Background: Anxiolytic properties of Korean Red Ginseng (KRG) have been previously reported. However, the exact mechanism(s) of action remains to be elucidated. The present study investigated the effect of KRG on immobilization-induced anxiety-like behaviors in mice and explored the involvement of the serotonin and GABA systems and BDNF in the anxiolytic action. Methods: Mice were orally administered with KRG (200 mg/kg/day) for 4 weeks and immobilized once daily for 2 h. p-Chlorophenylalanine (p-CPA) was intraperitoneally injected on day 22-28, and flumazenil or bicuculline was injected on day 25-28. After behavioral evaluations, brains were dissected for biochemical analyses. Results: KRG improved immobilization-induced anxiety-like behaviors in mice, as assessed by the elevated plus maze (EPM) and marble burying tests (MBT). The anxiolytic effect of KRG was comparable to that of fluoxetine, a reference drug clinically used for anxiety disorders. A serotonin synthesis inhibitor, p-CPA, blocked the effect of KRG in the EPM and MBT, indicating the requirement of serotonin synthesis for anxiolytic action. In addition, the anxiolytic effect of KRG was inhibited by bicuculline (a GABAA antagonist) in MBT, implying the involvement of GABA transmission. Western blotting analyses revealed that KRG upregulated the expression of tryptophan hydroxylase and GABAA receptor in the brain, which was blocked by p-CPA. Enhanced BDNF expression by KRG in the hippocampus was also indicated to mediate the anxiolytic action of KRG in immobilized mice. Conclusion: KRG exhibited the anxiolytic effect in immobilized mice by multiple mechanisms of action, involving enhanced serotonin and GABA transmissions and BDNF expression.