• Applied Microscopy
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• v.42 no.4
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• pp.200-206
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• 2012

Induction of neurogenesis can occur in the hippocampus in response to various pathological conditions, such as Alzheimer's disease. The aim of this study was to investigate the changes that occur in endogenous neural stem cells in response to amyloid beta $(A{\beta})_{25-35}$-induced neuronal cell damage in organotypic hippocampal slice cultures. Cresyl violet staining and Fluoro-Jade B staining were used to detect neuronal cell damage and changes of mossy fiber terminals were observed by Timm's staining. The immunofl uorescence staining was used to detect the newly generated cells in the subgranular zone (SGZ) of the dentate gyrus with specific marker, 5-bromo-2'-deoxyuridine (BrdU), Ki-67, Nestin, and doublecortin (DCX). In compared to control slices, neuronal cell damage was observed and the mossy fibers were expanded to CA3 area by treatment with $A{\beta}_{25-35}$. Ki-67/Nestin- and BrdU/DCX-positive cells were detected in the SGZ. In conclusion, these results demonstrate that $A{\beta}$-induced neuronal damage results in an increase in endogenous neural stem cells in rat hippocampal slice cultures not only for gliosis but also for neurogenesis.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.30-37
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• 2005

Xuesaitong Ruanjiaonang (XR), a soft capsule containing Panax notoginseng saponins as main ingredients, is believed to remove extravasated blood and increase cerebral blood flow by improving blood circulation, and therefore, has been used in China to treat ischemic stroke or hemiplegia caused by cerebral thrombosis. To characterize pharmacological actions of XR, the present study evaluated its effects on neuronal cell damage induced by various oxidative insults or excitotoxic amino acids in primary cultured rat cortical cells. The neuronal cell viability was not affected by XR with the exposure for 2 h at the concentrations tested in this study ($10{\sim}1000\;{\mu}g/ml$). However, significant reduction of the cell viability was observed when the cultured cells were exposed to XR at $1000\;{\mu}g/ml$ for 24 h. XR was found to concentration-dependently inhibit the oxidative neuronal damage induced by $H_{2}O_2$, xanthine/xanthine oxidase or $Fe^{2+}$/ascorbic acid. In addition, it dramatically inhibited the excitotoxic damage induced by glutamate or N-methyl-D-aspartate (NMDA). We found that the NMDA-induced neurotoxicity was inhibited more effectively and potently than the glutamate-induced toxicity. Moreover, XR was found to exert mild inhibition of lipid peroxidation induced by $Fe^{2+}$/ascorbic acid in rat brain homogenates and some 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Taken together, these results demonstrate neuroprotective and antioxidant effects of XR, showing inhibition of oxidative and excitotoxic damage in the cultured cortical neurons, as well as inhibition of lipid peroxidation and its radical scavenging activity. Considering that excitotoxicity and oxidative stress pl ay crucial roles in neuronal cell damage during ischemia and reperfusion, these results may provide pharmacological basis for its clinical usage to treat ischemic stroke.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.6
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• pp.287-291
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• 2008

Ampicillin, a $\beta$-lactam antibiotic, has been reported to induce astrocytic glutamate transporter-l which plays a crucial role in protecting neurons against glutamate excitotoxicity. We investigated the effect of ampicillin on neuronal damage in the mouse hippocampus and neostriatum following transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral occlusion of the common carotid artery for 40 min. Ampicillin was administered post-ischemically (for 3 days) and/or pre-ischemically (for $3{\sim}5$ days until one day before the onset of ischemia). Pre- and post-ischemic treatment with ampicillin (50 mg/kg/day or 200 mg/kg/day) prevented ischemic neuronal death in the medial CAI area of the hippocampus as well as the neostriatum in a dose-dependent manner. In addition, ischemic neuronal damage was reduced by pre-ischemic treatment with ampicillin (200 mg/kg/day). In summary, our results suggest that ampicillin plays a functional role as a chemical preconditioning agent that protects hippocampal neurons from ischemic insult.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.145-151
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• 2019

Methamphetamine (METH) acts strongly on the nervous system and damages neurons and is known to cause neurodegenerative diseases such as Alzheimer's and Parkinson's. Flavonoids, polyphenolic compounds present in green tea, red wine and several fruits exhibit antioxidant properties that protect neurons from oxidative damage and promote neuronal survival. Especially, epicatechin (EC) is a powerful flavonoid with antibacterial, antiviral, antitumor and antimutagenic effects as well as antioxidant effects. We therefore investigated whether EC could prevent METH-induced neurotoxicity using HT22 hippocampal neuronal cells. EC reduced METH-induced cell death of HT22 cells. In addition, we observed that EC abrogated the activation of ERK, p38 and inhibited the expression of CHOP and DR4. EC also reduced METH-induced ROS accumulation and MMP. These results suggest that EC may protect HT22 hippocampal neurons against METH-induced cell death by reducing ER stress and mitochondrial damage.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.123-128
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• 2015

Previously, we investigated extremely low-frequency magnetic fields (ELF-MFs) on diverse DNA damage responses, such as phosphorylated H2AX (${\gamma}H2AX$), comet tail moments, and aneuploidy production in several non-tumorigenic epithelial or fibroblast cell lines. However, the effect of ELF-MF on DNA damage responses in neuronal cells may not be well evaluated. Here, we investigated the effects of ELF-MF on the DNA damage responses in HT22 non-tumorigenic mouse neuronal cells. Exposure to a 60-Hz, 2 mT ELF-MF did not produce any increased ${\gamma}H2AX$ expression, comet tail moments, or aneuploidy formation. However, 2 mT ELF-MF transiently increased the cell number. From the results, ELF-MF could affect the DNA damage responses differently, depending on the cell lines.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.369-375
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• 2003

Xiaoshuan Zaizao Wan (XZW) has been used in China to improve hemiplegia, deviation of eye and mouth, and dysphasia due to cerebral thrombosis. To characterize pharmacological actions of XZW, we evaluated its effects on neuronal cell damage induced in primary cultured rat cortical cells by various oxidative insults, glutamate or N-methyl-D-aspartate (NMDA), and $\beta$-amyloid fragment ($A_{\beta(25-35)}$). XZW was found to inhibit the oxidative neuronal damage induced by $H_2O_2$, xanthine/xanthine oxidase, or $Fe^{2+}$/ascorbic acid. It also attenuated the excitotoxic damage induced by glutamate or NMDA. The NMDA-induced neurotoxicity was more effectively inhibited than the glutamate-induced toxicity. In addition, we found that XZW protected neurons against the $A_{\beta(25-35)}$-induced toxicity. Moreover; XZW exhibited dramatic inhibition of lipid peroxidation in rat brain homogenates and mild 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Taken together; these results demonstrate that XZW exerts neuroprotective effects against oxidative, excitotoxic, or $A_{\beta(25-35)}$-induced neuronal damage. These findings may provide pharmacological basis for its clinical usage treating the sequelae caused by cerebral thrombosis. Furthermore, XZW may exert beneficial effects on Alzheimer's disease and other oxidative stress-related neurodegenerative disorders.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.40-49
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• 2018

We evaluated the antioxidant activity and neuronal cell-protective effect of fucoidan extract from Ecklonia cava (FEC) on hydrogen peroxide ($H_2O_2$)-induced cytotoxicity in PC-12 and MC-IXC cells to assess its protective effect against oxidative stress. Antioxidant activities were examined using the ABTS radical scavenging activity and malondialdehyde-inhibitory effect, and the results showed that FEC had significant antioxidant activity. Intracellular ROS contents and neuronal cell viability were investigated using the DCF-DA assay and MTT reduction assay. FEC also showed remarkable neuronal cell-protective effect compared with vitamin C as a positive control for both $H_2O_2$-treated PC-12 and MC-IXC cells. Based on the neuronal cell-protective effects, mitochondrial function was analyzed in PC-12 cells, and FEC significantly restored mitochondrial damage by increasing the mitochondrial membrane potential (${\Delta}{\Psi}m$) and ATP levels and regulating mitochondrial-mediated proteins (p-AMPK and BAX). Finally, the inhibitory effects against acetylcholinesterase (AChE), which is a critical hydrolyzing enzyme of the neurotransmitter acetylcholine in the cholinergic system, were investigated ($IC_{50}$ value = 1.3 mg/ml) and showed a mixed (competitive and noncompetitive) pattern of inhibition. Our findings suggest that FEC may be used as a potential material for alleviating oxidative stress-induced neuronal damage by regulating mitochondrial function and AChE inhibition.

• Biomolecules & Therapeutics
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• v.28 no.5
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• pp.381-388
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• 2020

Methamphetamine (METH) is a highly addictive psychostimulant and one of the most widely abused drugs worldwide. The continuous use of METH eventually leads to drug addiction and causes serious health complications, including attention deficit, memory loss and cognitive decline. These neurological complications are strongly associated with METH-induced neurotoxicity and neuroinflammation, which leads to neuronal cell death. The current review investigates the molecular mechanisms underlying METH-mediated neuronal damages. Our analysis demonstrates that the process of neuronal impairment by METH is closely related to oxidative stress, transcription factor activation, DNA damage, excitatory toxicity and various apoptosis pathways. Thus, we reach the conclusion here that METH-induced neuronal damages are attributed to the neurotoxic and neuroinflammatory effect of the drug. This review provides an insight into the mechanisms of METH addiction and contributes to the discovery of therapeutic targets on neurological impairment by METH abuse.

• Nutrition Research and Practice
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• v.12 no.2
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• pp.93-100
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• 2018

BACKGROUND/OBJECTIVE: Oxidative stress plays a key role in neuronal cell damage, which is associated with neurodegenerative disease. The aim of present study was to investigate the neuroprotective effects of perilla oil (PO) and its active component, alpha-linolenic acid (ALA), against hydrogen peroxide $(H_2O_2)$-induced oxidative stress in SH-SY5Y neuronal cells. MATERIALS/METHODS: The SH-SY5Y human neuroblastoma cells exposed to $250{\mu}M$ $H_2O_2$ for 24 h were treated with different concentrations of PO (25, 125, 250 and $500{\mu}g/mL$) and its major fatty acid, ALA (1, 2.5, 5 and $25{\mu}g/mL$). We examined the effects of PO and ALA on $H_2O_2$-induced cell viability, lactate dehydrogenase (LDH) release, and nuclear condensation. Moreover, we determined whether PO and ALA regulated the apoptosis-related protein expressions, such as cleaved-poly ADP ribose polymerase (PARP), cleaved caspase-9 and -3, BCL-2 and BAX. RESULTS: Treatment of $H_2O_2$ resulted in decreased cell viability, increased LDH release, and increase in the nuclei condensation as indicated by Hoechst 33342 staining. However, PO and ALA treatment significantly attenuated the neuronal cell death, indicating that PO and ALA potently blocked the $H_2O_2$-induced neuronal apoptosis. Furthermore, cleaved-PARP, cleaved caspase-9 and -3 activations were significantly decreased in the presence of PO and ALA, and the $H_2O_2$-induced up-regulated BAX/BCL-2 ratio was blocked after treatment with PO and ALA. CONCLUSIONS: PO and its main fatty acid, ALA, exerted the protective activity from neuronal oxidative stress induced by $H_2O_2$. They regulated apoptotic pathway in neuronal cell death by alleviation of BAX/BCL-2 ratio, and down-regulation of cleaved-PARP and cleaved caspase-9 and -3. Although further studies are required to verify the protective mechanisms of PO and ALA from neuronal damage, PO and ALA are the promising agent against oxidative stress-induced apoptotic neuronal cell death.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.117-125
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• 2007

Neuronal ischemia is a pathological process caused by a lack of oxygen (anoxia) and glucose (hypoglycemia), resulting in neuronal death. It is believed that apoptosis is one of the mechanisms involved in ischemic cell death. Neuronal apoptosis is a process characterized by nuclear DNA fragmentation, changes of plasma membrane organization. To elucidate the mechanism of neuronal death following ischemic insult and to develop neuroprotective effects of Daebowonjeon(DBWJ) against ischemic damage, in vitro models are used. In vitro models of cell death have been devloped with pheochromocytoma (PC12) cell, which have become widely used as neuronal models of oxidative stress, trophic factor, serum deprivation and chemical hypoxia. Using a special ischemic device and PC12 cultures, we investigated an in vitro model of ischemia based on combined Oxygen and Glucose Deprivation (OGD) insult, followed by reoxygenation, mimicking the pathological conditions of ischemia. In this study, Daebowonjeon rescued PC12 cells from Oxygen-Glucose Deprivation (OGD)-induced cell death in a dose-dependent manner The nuclear staining of PC12 cells clearly showed that DBWJ attenuated nuclear condensation and fragmentation which represent typical neuronal apoptotic characteristics. DBWJ also prevents the LDH release and induction of Hypoxia Inducing Factor (HIF)-1 by OGD-exposed PC12 cells. Furthermore, DBWJ reduced the activation of polyADP-ribose polymerase (PARP) by OGO-exposed PC12 cells. These results suggest that apoptosis is an important characteristic of OGD-induced neuronal death and that oriental medicine, such as DBWJ, may prevent PC12 cell from OG D-induced neuronal death by inhibiting the apoptotic process.