• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.316-322
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• 2012

Siegesbeckia Herba is known to have anti-oxidant, anti-inflammatory, anti-allergic and anti-tumor. The objective of this study is to explore the neuroprotective effect of Siegesbeckia Herba against glutamate-induced oxidative stress in mouse hippocampal HT22 cells. Siegesbeckia Herba 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 the mouse hippocampal HT22 cells. Especially, ethyl acetate fraction showed higher protective effect. In HT22 cell, Siegesbeckia Herba ethyl acetate fraction makes the nuclear accumulation of Nrf2. Further, we found that treatment with c-JUN N-terminal kinase (JNK) inhibitor (SP600125) reduced Siegesbeckia Herba ethyl acetate fraction induced HO-1 expression and Siegesbeckia Herba ethyl acetate fraction also increased JNK phosphorylation. In conclusion, the ethyl acetate fraction of 70% ethanol extract of Siegesbeckia Herba significantly protect glutamate-induced oxidative damage by induction of HO-1 via Nrf2 and JNK pathway in mouse hippocampal HT22. Taken together these finding suggest that Siegesbeckia Herba ethyl acetate fraction good source for taking active compounds and may be a potential therapeutic for brain disorder by targeting the oxidative stress of neuronal cell.

• Journal of Life Science
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• v.26 no.12
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• pp.1458-1465
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• 2016

We investigated the neuroprotective effect of an ethanol extract from Asparagus cochinchinensis (AC) against glutamate-induced toxicity in the HT22 hippocampal cell, which is an ideal in vitro model for oxidative stress. The neuroprotective effects of AC in HT22 cells were evaluated by analyzing cell viability, lactate dehydrogenase (LDH), flow cytometry for cell death types, reactive oxygen species (ROS), mitochondria membrane potential (MMP), and Western blot assays. In the cell death analysis, AC treatment resulted in significantly attenuated glutamate-induced loss of cell viability with a decrease in LDH release. AC treatment also reduced glutamate-induced apoptotic cell death. In the ROS and MMP analysis, AC treatment inhibited the elevation of intracellular ROS induced by glutamate exposure and the disruption of MMP. In oxidative stress-related proteins analysis, AC treatment inhibited the expression of poly ADP ribose polymerase and heme oxygenase-1 by glutamate. These results indicate that AC exerts a significant neuroprotective effect against glutamate-induced hippocampal damage by decreasing ROS production and stabilizing MMP. Thus, AC potentially provides a new strategy for the treatment of oxidative stress-related diseases.

• 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.

• Korean Journal of Acupuncture
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• v.38 no.1
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• pp.32-42
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• 2021

Objectives : In this study, we investigated the neuroprotective effects of ethanol extract of Lonicera japonica flower buds (EELJ) on glutamate-induced neurotoxicity in mouse hippocampus-derived neuronal HT22 cells. Methods : After analyzing the cytoprotective effect of EELJ on glutamate in HT22 cells, the inhibitory effect of apoptosis was studied using flow cytometry. In order to analyze the antioxidant efficacy of EELJ, the levels of reactive oxygen species (ROS) and glutathione (GSH) were investigated, and the effects on the activities of superoxide dismutase (SOD) and catalase (CAT) were also analyzed. Furthermore, the effect of EELJ on the expression of apoptosis regulators such as Bax and Bcl-2 in glutamate-treated HT22 cells was investigated. Results : According the current results, pretreatment with EELJ significantly reduced glutamate-induced loss of cell viability and release of lactate dehydrogenase. EELJ also markedly attenuated glutamate-induced generation of intracellular ROS, which was associated with increased levels of GSH, and activity of SOD and CAT in glutamate-stimulated HT22 cells. In addition, EELJ was strikingly inhibited glutamate-induced apoptosis in HT22 cells. Furthermore, the expression of pro-apoptotic Bax was increased and the expression of anti-apoptotic Bcl-2 was decreased in glutamate-treated HT22 cells, while in the presence of EELJ, their expressions were maintained at the control levels. Conclusions : These findings indicate that EELJ protects glutamate-induced cytotoxicity in HT22 hippocampal neurons through antioxidant activity. Therefore, although identification of biologically active substances of EELJ and re-evaluation through animal experiments is necessary, this natural substance is a promising candidate for further research in preventing and treating oxidative stress-mediated neurodegenerative diseases.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.213-217
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• 2008

Oxidative stress is considered to play an important role in a variety of neurodegenerative disorders of central nervous system. The immortalized mouse hippocampal cell line, HT22, phenotypically resembles neuronal precursor cells but lacks functional ionotropic glutamate receptors, thus excluding excitotoxicity as a cause for glutamate triggered cell death. Therefore, HT22 cells are a useful model for studying oxidative glutamate toxicity. In this study, we examined whether the methanol extracts of some native plants at Mt. Baekdu could protect HT22-immortalized hippocampal cells against glutamate-induced oxidative stress. Seventy-eight plants sources were collected at Mt. Baekdu, and extracted with methanol. These extracts had been screened the protective effects against glutamate-induced oxidative damage in HT22 cells at the 100 and 300 ${\mu}g/ml$. Of these, thirteen methanolic extracts, Acer mono (leaf), Artemisia stolonifera (aerial part), Carduus crispus (aerial part), Carex mongolica (whole plant), Clematis hexapetala (whole plant), Galeopsis bifida (aerial part), Galium verum (whole plant), Ganoderma lucidum (whole plant), Ixeris chinensis (whole plant), Malva verticillata (aerial part), Polygonum senticosum (whole plant), Rebes mandshricum (branch), and Taraxacum mongolicum (aerial part), showed significant protective effects against glutamate-induced oxidative damage in HT22 cells.

• 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.

• Korean Journal of Pharmacognosy
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• v.44 no.4
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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.

• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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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.

• Journal of Ginseng Research
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• v.42 no.2
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• pp.225-228
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• 2018

Our results suggested that thermal stress can lead to activation of hippocampal cell damage and reduction of memory-associated molecules in HT22 cells. These findings also provide a part of molecular rationale for the role of ginsenoside Rg5 as a potent cognitive impairment preventive compound in blocking the initiation of hippocampal damage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1019-1024
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• 2009

Diabetic neuropathy is characterized by the decrease of cell viability in neuron, which is induced by the hyperglycemia. HT22 cell is the neuron cell line originated from hippocampus. Ginsenosides have been reported to retain anti-diabetic effect. However, the preventive effect of ginsenosides in the condition of diabetic neuropathy was not elucidated. Thus, this study was conducted to examine the protective effect of ginsenoside total saponin (GTS), panoxadiol (PD), and panoxatriol (PT) in the high glucose-induced cell death of HT22 cells, an in vitro cellular model for diabetic neuropathy. In present study, high glucose increased lactate dehydrogenase(LDH) activity, the lipid peroxide(LPO) formation and induced the decrease of cell viability. These effects were completely prevented by the treatment of GTS, but partially prevented by the treatment of PD and PT. High glucose also increased the expression of Bax and cleaved form of caspase-3 but decreased that of Bcl-2. These effects of high glucose on Bax, Bcl-2 and cleaved form of caspase-3 were completely prevented by the treatment of GTS, but partially prevented by the treatment of PD and PT in HT22 cells. In conclusion, ginsenosides prevented high glucose-induced cell death of hippocampal neuron through the inhibition of oxidative stress and apoptosis in HT 22 cells.