• Molecules and Cells
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• v.39 no.8
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• pp.603-610
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• 2016

Recently, an increasing number of studies have focused on the effects of CD4+ T cell on cognitive function. However, the changes of Th2 cytokines in restricted CD4+ T cell receptor (TCR) repertoire model and their effects on the adult hippocampal neurogenesis and memory are not fully understood. Here, we investigated whether and how the mice with restricted CD4+ repertoire TCR exhibit learning and memory impairment by using OT-II mice. OT-II mice showed decreased adult neurogenesis in hippocampus and short- and long- term memory impairment. Moreover, Th2 cytokines in OT-II mice are significantly increased in peripheral organs and IL-4 is significantly increased in brain. Finally, IL-4 treatment significantly inhibited the proliferation of cultured adult rat hippocampal neural stem cells. Taken together, abnormal level of Th2 cytokines can lead memory dysfunction via impaired adult neurogenesis in OT-II transgenic.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.531-544
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• 2002

Ginseng is the best known and most popular herbal medicine used worldwide. Ameliorating effects of ginseng were observed on the models of scopolamine-induced, aged or hippocampal lesioned learning and memory deficits. Further beneficial effects of ginseng were observed on neuronal cell death associated with ischemia or glutamate toxicity. In spite of these beneficial effects of ginseng on the CNS, little scientific evidence shows at the cellular level. In the present study, we have employed cultures of rat hippocampal neurons and examined the direct modulation of ginseng on NMDA receptor-induced changes in $[Ca^{2+}]_i$ and -gated currents using fura-2-based digital imaging and perforated whole-cell patch-clamp techniques, respectively. We found that ginseng total saponins inhibited NMDA-induced but less effectively glutamate-induced increase in $[Ca^{2+}]_i$ Ginseng total saponins also modulated $Ca^{2+}$ transients evoked by depolarization with 50 mM KCI along with its own effects on $[Ca^{2+}]_i$. Among ginsenosides tested, ginsenoside $Rg_3$ was found to be the most potent component for ginseng actions on NMDA receptors. Furthermore, we examined the inhibitory effects ofbiotransformants of ginsenosides on NMDA receptor using purified stereoisomers of ginsenosides. 20(S)-ginsenoside $Rg_3$ and its metabolite, 20(S)-ginsenoside $Rh_3$, produced the strongest inhibition while 20(S)-ginsenoside $Rh_1$ and Compound K produced the moderate inhibition on NMDA-induced increase in $[Ca^{2+}]_i$. The data obtained suggest that the inhibition of NMDA receptors by ginseng, in particular by 20(S)-ginsenoside $Rg_3$ and its metabolite, 20(S)-ginsenoside $Rh_2$, could be one of mechanisms for ginsengmediated neuroprotective actions.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.61.2-61.2
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• 2008

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.63.2-63.2
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• 2008

• Korean Journal of Pharmacognosy
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• v.42 no.2
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• pp.175-181
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• 2011

Oxidative stress or accumulation of reactive oxygen species (ROS) leads neuronal cellular death and dysfunction, and it contributes to neuronal degenerative disease such as Alzheimer's disease, Parkinson's disease and stroke. Glutamate is one of the major excitatory neurotransmitter in the central nervous system (CNS). Glutamate contributes to fast synaptic transmission, neuronal plasticity, outgrowth and survival, behavior, learning and memory. In spite of these physiological functions, high concentration of glutamate causes neuronal cell damage, acute insults and chronic neuronal neurodegenerative diseases. Heme oxygenase-1 (HO-1) enzyme plays an important role of cellular antioxidant system against oxidant injury. NNMBS020, the water-insoluble fraction of the 70% EtOH extract of root barks of Dictamnus dasycarpus, showed dominant neuroprotective effects on glutamate-induced neurotoxicity in mouse hippocampal HT22 cells by induced the expression of HO-1 and increased HO activity. In mouse hippocampal HT22 cells, NNMBS020 makes the nuclear accumulation of Nrf2 and stimulates extracellular signal-regulated kinase (ERK) pathway. The ERK MAPK pathway inhibitor significantly reduced NNMBS020-induced HO-1 expression, whereas the JNK and p38 inhibitors did not. In conclusion, the water-insoluble fraction of the 70% EtOH extract of root barks of D. dasycarpus (NNMBS020) significantly protect glutamate-induced oxidative damage by induction of HO-1 via Nrf2 and ERK pathway in mouse hippocampal HT22 cells.

• The Korea Journal of Herbology
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• v.30 no.2
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• pp.43-48
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• 2015

Objectives : The aim of this study was to investigate the memory enhancing properties of extract of Hoelen Cum Radix (HCR) and its possible mechanism in mice of normal condition. Methods : We evaluated the effects of HCR on cognitive function and memory enhancement in normal mice. Male ICR mice were orally administrated with HCR 100 mg/kg for 7 days and equal volume of saline was administrated to the control group in the same condition. We conducted two behavioral tests which measure the spatial working memory (Y-maze test) and cognitive fear memory (passive avoidance test). We also investigated whether HCR affects the hippocampal neurogenesis in the brain. To assess the effects of HCR on neural progenitor cell differentiation and neurite outgrowth in the early stage of hippocampal neurogenesis, we performed doublecortin (DCX), a direct neurogenesis marker, immunohistochemical analysis in the dentate gyrus (DG) of the mouse hippocampus. Results : HCR significantly enhanced memory and cognitive function as determined by the Y-maze test (p<0.05) and passive avoidance test (p<0.001). Moreover, HCR increased DCX positive cells (p<0.01) and neurite length (p<0.01) compared to the control group. These results indicated that HCR stimulates differentiation of neural progenitor cells and promotes neurite outgrowth in hippocampal DG of the mice. Conclusion : We concluded that HCR shows memory enhancing effects through the stimulation of hippocampal neurogenesis as a consequence of accelerated neuronal differentiation and neurite outgrowth in the DG of the hippocampus after HCR treatment.

• The Journal of Korean Medicine
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• v.24 no.4
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• pp.127-135
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• 2003

Objectives : Intracerebral hemorrhage (ICH) is one of the most devastating types of stroke. The effect of acupuncture on the intrastriatal hemorrhage-induced neuronal cell death and cell proliferation in rats is examined. Methods : Cell death and cell proliferation in rats was investigated via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and immunohistochemistry for caspase-3 and 5-bromo-2'-deoxyuridine (BrdU). Results : Results showed that apoptotic cell death in the striatum and cell proliferation in the hippocampal dentate gyrus significantly increased following intrastriatal hemorrhage in rats, and that acupunctural treatment at the Zusanli acupoint suppressed the hemorrhage-induced increase in apoptosis in the striatum and cell proliferation in the dentate gyrus. Conclusions : It is suggested that acupunctural treatment, especially at the Zusanli acupoint, may aid recovery following central nervous system sequelae following ICH.

• Food Science and Preservation
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• v.31 no.1
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• pp.99-111
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• 2024

The antioxidant potentials of ethanolic extracts derived from Aster yomena (A. yomena) were evaluated by assessing their total phenolic and flavonoid contents and radical scavenging activities. Our findings revealed that the 60% ethanolic extract of A. yomena exhibited the most robust antioxidant properties among all extracts tested. Specifically, the IC₅₀ values for the 2,2'-azino-bis (3-ethyl benzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities of the 60% ethanolic extract from A. yomena were determined to be 1,640.30 ㎍/mL and 2,655.10 ㎍/mL, respectively. Moreover, the inhibitory effect on malondialdehyde increased with the 60% ethanolic extract from A. yomena. To assess the neuroprotective effects, we examined the impact of the 60% ethanolic extract from A. yomena against H₂O₂-induced cytotoxicity in HT-22 (mouse hippocampal neuronal cell line) and SK-N-MC (human neuroblastoma cell line) cells. The results demonstrated a significant improvement in cell viability and reduced intracellular oxidative stress. Furthermore, the major bioactive compounds present in the 60% ethanolic extract from A. yomena were identified as chlorogenic acid and rutin through high-performance liquid chromatography (HPLC) analysis.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.190-192
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• 2009

Kainic acid (KA), an agonist for kainate and AMPA receptors, is an excitatory neurotoxic substance. Vitamin E such as alpha-tocopherol and alpha-tocotrienol is a chain-breaking antioxidant, preventing the chain propagation step during lipid peroxidation. In the present study, we have investigated the neuroprotective effects of alphatocopherol and alpha-tocotrienol on KA-induced neuronal death using organotypic hippocampal slice culture (OHSC). After 15h KA treatment, delayed neuronal death was detected in CA3 region. Alpha-tocopherol and alpha-tocotrienol increased cell survival and reduced the number of TUNEL-positive cells in CA3 region. These data suggest that alpha-tocopherol and alpha-tocotrienol treatment have protective effects on KA-induced cell death

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.218-223
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• 2008

Oxidative stress is believed to contribute to the neuronal damage induced by cerebral ischemia/reperfusion injury. The present study was undertaken to evaluate the possible antioxidant neuroprotective effect of hydroxyfullerene (a radical absorbing cage molecule) against neuronal death in hippocampal CA1 neurons following transient global cerebral ischemia in the rat. Transient global cerebral ischemia was induced in male Wistar rats by four vessel- occlusion (4VO) for 10 min. Lipid peroxidation in brain tissues was determined by measuring the concentrations of thiobarbituric acid-reactive substances (TBARS). Furthermore, the apoptotic effects of ${H_2}{O_2}$ on PC12 cells were also investigated. Cell viabilities were measured using MTT [3-(4,5-dimethylthiazolyl-2)-2,-5-diphenyltetrazolium bromide] assays. Hydroxyfullerene, when administered to rats at 0.3-3 mg/kg i.p. at 0 and 90 minutes after 4-VO was found to significantly reduce CA1 neuron death by 72.4% on hippocampal CA1 neurons. Our findings suggest that hydroxyfullerene protects neurons from transient global cerebral injury in the rat hippocampus by reducing oxidative stress and lipid peroxidation levels, which contribute to apoptotic cell death.