• Journal of Ginseng Research
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• v.39 no.3
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• pp.257-264
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• 2015

Background: Korean Red Ginseng-a steamed root of Panax ginseng Meyer-has long been used as a traditional medicine in Asian countries. Its antipruritic effect was recently found, but no molecular mechanisms were revealed. Thus, the current study focused on determining the underlying molecular mechanism of Korean Red Ginseng extract (RGE) against histamine-induced itch at the peripheral sensory neuronal level. Methods: To examine the antipruritic effect of RGE, we performed in vivo scratching behavior test in mice, as well as in vitro calcium imaging and whole-cell patch clamp experiments to elucidate underlying molecular mechanisms. Results: The results of our in vivo study confirmed that RGE indeed has an antipruritic effect on histamine-induced scratching in mice. In addition, RGE showed a significant inhibitory effect on histamine-induced responses in primary cultures of mouse dorsal root ganglia, suggesting that RGE has a direct inhibitory effect on sensory neuronal level. Results of further experiments showed that RGE inhibits histamine-induced responses on cells expressing both histamine receptor subtype 1 and TRPV1 ion channel, indicating that RGE blocks the histamine receptor type 1/TRPV1 pathway in sensory neurons, which is responsible for histamine-dependent itch sensation. Conclusion: The current study found for the first time that RGE effectively blocks histamine-induced itch in peripheral sensory neurons. We believe that the current results will provide an insight on itch transmission and will be helpful in understanding how RGE exerts its antipruritic effects.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.4
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• pp.281-285
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• 2012

A previous animal study has shown the effects of erythropoietin (EPO) and its non-erythropoietic carbamylated derivative (CEPO) on neurogenesis in the dentate gyrus. In the present study, we sought to investigate the effect of EPO on adult hippocampal neurogenesis, and to compare the ability of EPO and CEPO promoting dendrite elongation in cultured hippocampal neural progenitor cells. Two-month-old male BALB/c mice were given daily injections of EPO (5 U/g) for seven days and were sacrificed 12 hours after the final injection. Proliferation assays demonstrated that EPO treatment increased the density of bromodeoxyuridine (BrdU)-labeled cells in the subgranular zone (SGZ) compared to that in vehicle-treated controls. Functional differentiation studies using dissociated hippocampal cultures revealed that EPO treatment also increased the number of double-labeled BrdU/microtubulea-ssociated protein 2 (MAP2) neurons compared to those in vehicle-treated controls. Both EPO and CEPO treatment significantly increased the length of neurites and spine density in MAP2(+) cells. In summary, these results provide evidences that EPO and CEPO promote adult hippocampal neurogenesis and neuronal differentiation. These suggest that EPO and CEPO could be a good candidate for treating neuropsychiatric disorders such as depression and anxiety associated with neuronal atrophy and reduced hippocampal neurogenesis.

• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.388-396
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• 2009

The present study investigated an ethanol extract (HS0608) of a mixture of three medicinal plants of Curcuma longae radix, Phellinus linteus, and Scutellariae radix for possible neuroprotective effects on neurotoxicity induced by amyloid $\beta$ protein ($A{\beta}$) (25-35) in cultured rat cortical neurons and antidementia activity in mice. Exposure of cultured cortical neurons to $10\;{\mu}M$ $A{\beta}$ (25-35) for 36 h induced neuronal apoptotic death. At $1-50\;{\mu}g/m{\ell}$, HS0608 inhibited neuronal death, elevation of intracellular calcium concentration ($[Ca^{2+}]_i$), and generation of reactive oxygen species (ROS) induced by $A{\beta}$ (25-35) in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of ICR mice with 15 nmol $A{\beta}$ (25-35) was inhibited by chronic treatment with HS0608 (25, 50 and 100 mg/kg, p.o. for 7 days) as measured by a passive avoidance test. From these results, we suggest that the antidementia effect of HS0608 is due to its neuroprotective effect against $A{\beta}$ (25-35)-induced neurotoxicity and that HS0608 may have a therapeutic role in preventing the progression of Alzheimer's disease.

• Korean Journal of Medicinal Crop Science
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• v.20 no.1
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• pp.8-15
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• 2012

The present study investigated an ethanol extract of Chaenomeles sinensis fruit (CSF) for possible neuroprotective effects on neurotoxicity induced by amyloid ${\beta}$ protein ($A{\beta}$) (25-35) in cultured rat cortical neurons and also for antidementia activity in mice. Exposure of cultured cortical neurons to $10{\mu}M\;A{\beta}$ (25-35) for 36 h induced neuronal apoptotic death. At $0.1-10{\mu}g/m{\ell}$, CSF inhibited neuronal death, elevation of intracellular calcium concentration ($[Ca^{2+}]_i$), and generation of reactive oxygen species (ROS) induced by $A{\beta}$ (25-35) in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of mice with 15 nmol $A{\beta}$ (25-35) was inhibited by chronic treatment with CSF (10, 25 and 50 mg/kg, p.o. for 7 days) as measured by a passive avoidance test. CSF (50 mg/kg) inhibited the increase of cholinesterase activity in $A{\beta}$ (25-35)-injected mice brain. From these results, we suggest that the antidementia effect of CSF is due to its neuroprotective effect against $A{\beta}$ (25-35)-induced neurotoxicity and that CSF may have a therapeutic role for preventing the progression of Alzheimer's disease.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.528-532
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• 2019

The dorsal root ganglion (DRG) was isolated from mouse embryos and Schwann cells and neuronal cells were cultured in vitro. The neurons and Schwann cells were cultured separately and the two kinds of cells were cultured together for three weeks. Generation of myelination was confirmed by transmission electron microscope and confocal microscope using a myelinaion protein, myelin protein zero (MPZ) antibody. The sindbis virus was infected for three days in the myelinated culture cells and then demyelination was carried out. The process of demyelination was also confirmed by transmission electron microscopy and confocal microscopy using myelin protein zero (MPZ) antibody. The study was supported by a Basic Research Program through the National Research Foundation (NRF) funded by the Ministry of Science and Technology, ICT and Future Plans (NRF-2016R1A2B4016552 and 2017R1A2B3005753).

• Journal of Oriental Neuropsychiatry
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• v.11 no.1
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• pp.1-18
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• 2000

To study the effects of Ramulus et Uncus Uncariae (REUU) on oxygen free radical-mediated damage by hydrogen peroxide $(H_{2}O_{2})$ on cultured spinal sensory neurons, in vitro assays such as MTT assay, NR assay, neurofilament enzymeimmuno assay (EIA), sulforhodamine B (SRB) assay, assay for lactate dehydrogenase (LDH) activity and assay for lipid peroxidation were used in cultured spinal dorsal root ganglion neurons derived from mice, Spinal dorsal root ganglion neurons were cultured in media containing various concentrations of $H_{2}O_{2}$ for 5 hours, after which the neurotoxic effect of $H_{2}O_{2}$ was measured by in vitro assay. The protective effect of the herb extract, Ramulus et Uncus Uncariae (REUU) against H2O2-induced neurotoxicity was also examined. The results are as follows. 1. In NR assay and MTT assay, $H_{2}O_{2}$ significantly decreased the cell viability of cultured mouse spinal dorsal root ganglion neurons according to exposure concentration in these cultures. An additional time course study was done on these cultures. 2. Cultured spinal dorsal root ganglion neurons which were exposed to various concentrations of $H_{2}O_{2}$ showed a quantitative decrease of neuronal cells by EIA and of total protein by sulforhodamine B (SRB) assay, while they showed an increase of both lipid peroxidation and LDH activity. 3. The effect of Ramulus et Uncus Uncariae (REUU) on $H_{2}O_{2}$ induced neurotoxicity showed a quantitative increase in both neurofilament and total protein, but showed a decrease of lipid peroxidation and LDH activity. These results suggest that $H_{2}O_{2}$ has a neurotoxic effect on cultured spinal dorsal root ganglion neurons from mice and that the herb extract, Ramulus et Uncus Uncariae (REUU), was very effective in protecting $H_{2}O_{2}$ induced neurotoxicity by decreasing lipid peroxidation and LDH activity.

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.165-177
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• 1995

Dissociated cell cultures from rat embryonic ventral mesencephalon were used to evaluate the mechanisms of $MPP^+$ neurotoxicity. The cells were treated with MPTP or $MPP^+$ and the viability of the cells was assessed biochemically; tyrosine hydroxylase (TH) immunoreactivity, protein, intracellular ATP and lactate content and lipid peroxidation. Also the generation of the intracellular oxidants was measured after loading 2', 7‘-dichlorofluorescin diacetate to the cells. When cultures were exposed to 0.1 mM $MPP^+$, at 2 hour incubation lactate was significantly accumulated in the cells and then the intracellular ATP content and TH immunoreactivity were decreased dose- and time-dependently. But, malondialdehyde as an index for lipid peroxidation was not changed even though the generation of the intracellular oxidants was stimulated by the addition of $MPP^+$. On the other hand, 1 mM MPTP significantly reduced the TH immunoreactivity at 24 hour exposure without any change in the intracellular A TP, lactate and MDA content until 6 hour exposure. And also MPTP inhibited the generation of the intracellular oxidants from control cells and $MPP^+$ exposed cells. These results indicate that cytotoxicity of $MPP^+$ is mediated by inhibiting the mitochondrial energy metabolism rather than generating the intracellular oxidants. And MPTP would have direct action in addition to conveting to the toxic metabolite, $MPP^+$ to exert the toxicity on the dopaminergic neurons.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.101-104
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• 2003

It has been suggested that oxidative stress of reactive oxygen species(ROS) may play a key role in the pathogenesis of neuronal complications. The aim of this study was to examine the cytotoxic effect of hydrogen peroxide(H₂O₂) in the cultured mouse cerebral neurons and the protective effect of Schisandrae Fructus(SF) on ROS-induced neurotoxicity. Cytotoxic effect of H₂O₂ and neuroprotective effect of SF were determined by MTT assay. H₂O₂ decreased cell viability in dose-and time-dependent mannner, and SF decreased H₂O₂-induced neurotoxicity in these cultures. From above the results, H₂O₂ has toxic effect, and herb extract, SF is very effective against H₂O₂-induced neurotoxicity in cultured cerebral neurons of mouse.

• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.380-388
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• 2018

Neural stem cells (NSCs) have the ability to self-renew and differentiate into multiple nervous system cell types. During embryonic development, the concentrations of soluble biological molecules have a critical role in controlling cell proliferation, migration, differentiation and apoptosis. In an effort to find optimal culture conditions for the generation of desired cell types in vitro, we used a microfluidic chip-generated growth factor gradient system. In the current study, NSCs in the microfluidic device remained healthy during the entire period of cell culture, and proliferated and differentiated in response to the concentration gradient of growth factors (epithermal growth factor and basic fibroblast growth factor). We also showed that overexpression of ASCL1 in NSCs increased neuronal differentiation depending on the concentration gradient of growth factors generated in the microfluidic gradient chip. The microfluidic system allowed us to study concentration-dependent effects of growth factors within a single device, while a traditional system requires multiple independent cultures using fixed growth factor concentrations. Our study suggests that the microfluidic gradient-generating chip is a powerful tool for determining the optimal culture conditions.

• Molecules and Cells
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• v.37 no.3
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• pp.248-256
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• 2014

N-acetylglucosamine kinase (GlcNAc kinase or NAGK; EC 2.7.1.59) is a N-acetylhexosamine kinase that belong to the sugar kinase/heat shock protein 70/actin superfamily. In this study, we investigated both the expression and function of NAGK in neurons. Immunohistochemistry of rat brain sections showed that NAGK was expressed at high levels in neurons but at low levels in astrocytes. Immunocytochemistry of rat hippocampal dissociate cultures confirmed these findings and showed that NAGK was also expressed at low levels in oligodendrocytes. Furthermore, several NAGK clusters were observed in the nucleoplasm of both neuron and glia. The overexpression of EGFP- or RFP (DsRed2)-tagged NAGK in rat hippocampal neurons (DIV 5-9) increased the complexity of dendritic architecture by increasing the numbers of primary dendrites and dendritic branches. In contrast, knockdown of NAGK by shRNA resulted in dendrite degeneration, and this was prevented by the co-expression of RFP-tagged NAGK. These results suggest that the upregulation of dendritic complexity is a non-canonical function of NAGK.