• International Journal of Oral Biology
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• v.49 no.1
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• pp.10-17
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• 2024

Glutamate-mediated oxidative stress causes neuronal cell death by increasing intracellular Ca²⁺ uptake, reactive oxidative species (ROS) generation, mitogen-activated protein kinase (MAPK) activation, and translocation of apoptosis-inducing factor (AIF) to the nucleus. In the current study, we demonstrated that corydaline exerts potent neuroprotective effects against glutamate-induced neurotoxicity. Treatment with 5 mmol/L glutamate increased cellular Ca²⁺ influx, ROS generation, MAPK activation, and AIF translocation. In contrast, corydaline treatment decreased cellular Ca²⁺ influx and ROS generation. Western blot analysis revealed that glutamate-mediated MAPK activation was attenuated by corydaline treatment. We further demonstrated that corydaline treatment inhibited the glutamate-mediated translocation of AIF to the nucleus. We propose that corydaline is a promising lead structure for the development of safe and effective neuroprotectants.

• Journal of Life Science
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• v.24 no.7
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• pp.737-742
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• 2014

The objective of this study was to investigate the fatty acid composition of raw and dried abalone (Haliotis discus hannai) and to determine the effect of abalone extracts on cytotoxic activity and anti-oxidant properties. Dried abalone was extracted with acetone/methylene chloride (A+M) and methanol (MeOH), and the extracts were fractionated using n-hexane, 85% aq. methanol (MeOH), butanol (BuOH), and water. Cytotoxic activity against HT-29 cancer cell lines was determined using the 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. Antioxidant activity was measured using a fluorescence sensitive dye, 2'-7' dichlorofluorescein-diacetate (DCFH-DA). The fatty acid composition of dried abalone was higher (22:6n-3) than that of raw abalone, and it had a lower percentage of 20:4n-6 than raw abalone. Analysis of cell viability showed that the crude extract treatments and fractions were cytotoxic, suppressing the growth of HT-29 cancer cell lines (p<0.05). The A+M extract showed a higher cytotoxic effect on the growth of HT-29 cells compared to the MeOH extract. Among the fractions, the 85% aq. MeOH fraction showed the strongest cytotoxicity against the growth of HT-29 cells. The highest activity in terms of scavenging reactive oxygen species (ROS) was likewise obtained with the use of 85% aq. MeOH. Our results suggest that the 85% aq. MeOH fraction has a potent inhibitory effect on the proliferation of human cancer cells.

• The Korea Journal of Herbology
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• v.26 no.3
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• pp.75-82
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• 2011

Objectives : In this study, we evaluated the effect of Chungganhaeju-hwan(CGHJH) on hydrogen peroxide($H_2O_2$)-induced and ethanol(EtOH)-induced neuronal damage in vitro and in vivo, respectively. Methods:We carried out the anti-oxidant effects of CGHJH against hydrogen peroxide($H_2O_2$)-induced toxicity in HT22 and PC12 cells using thiazolyl blue tetrazolium bromide. Then, to investigate the protective effect on CGHJH against EtOH-induced memory impairment and hippocampal cell damage in male ICR mice, we performed novel object recognition test(NORT), and analysed the brain tissues after immunohistochemistry and western blotting. Results:CGHJH showed protective effect from $H_2O_2$-induced cell toxicity at doses of $1\sim100{\mu}g$/mL in both HT22 and PC12 cells. CGHJH had also recovery effect from EtOH-induced memory impairment in ICR mice from NORT and it protected hippocampal cells against EtOH toxicity in the result of cresyl violet and NeuN immunoreactivity. Conclusion : These results demonstrate that CGHJH has protective effect in neuronal cells against $H_2O_2$ and EtOH toxicities and this effect could be a main role of recovery effect on EtOH-induced memory loss.

• The Korea Journal of Herbology
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• v.34 no.5
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• pp.29-37
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• 2019

Objectives : Bang-poong (Saposhnikovia divaricata; SD) was traditionally used to treat inflammatory disorders. In this study, we aimed to investigate whether Bang-poong and related species including SD, Glehnia littoralis (GL), and Peucedanum japonicum (PJ) possess neuroprotective effects and acetylcholinesterase (AChE) inhibitory activities. Methods : Roots of SD, GL and PJ were extracted with distilled water (DW) or 70% ethanol (EtOH). We assessed 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activities of the extracts. To examine neuroprotective effects, we measured cell viability in PC12 or HT22 cells after treatment of the extracts with $H_2O_2$ or amyloid-beta ($A{\beta}$). To assess anti-neuroinflammatory effects, we measured the nitric oxide (NO) levels after treatment with the extracts and lipopolysaccharide (LPS) in BV2 microglial cells. In addition, we performed AChE inhibition assay to explore effects of the extracts on the cholinergic system. Results : DW and EtOH extracts of SD, GL and PJ showed mild DPPH free radical scavenging activities. Also, DW extracts of GL and PJ showed protective effects against $H_2O_2$-induced toxicity in PC12 cells. In LPS-activated BV2 cells, EtOH extracts of SD, GL and PJ exerted inhibitory effects on NO production. Meanwhile, DW extracts of SD, GL and PJ inhibited the $A{\beta}$-induced cell death in HT22 cells. In addition, DW and EtOH extracts of GL exhibited remarkable inhibitory activities on AChE. Conclusions : We demonstrated that SD, GL and PJ exert anti-oxidative, anti-neuroinflammatory and AChE inhibitory activities. These results indicate that SD, GL and PJ could be potential candidates for neurological disorders.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.2
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• pp.328-332
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• 2010

Acupuncture has been used for the treatment and prevention of stress-related disorders. In the present study, the effect of electroacupuncture on the behavioral and biochemical responses to restraint stress was evaluated in rats. Sprague-Dawley male rats underwent to immobilization stress for 21 days (6 hours/day). Electroacupuncture (2 Hz, 2 mA, and 10 minutes) was applied either to the acupuncture point HT7 (Shenmen) or the nonacupuncture point in the tail for the last 7 days. Rats were randomly divided into four groups: the normal group (n=10, without the restraint stress), the stress group (n=10, with restraint stress), the HT7 group (n=10, with restraint stress and electroacupuncture to HT7), and the NA group (n=10, with restraint stress and electroacupuncture to the nonacupuncture point). The anxiety-related behavior was tested using the elevated plus maze and the Vogel test on day 22. The expression of tyrosine hydroxylase in the locus coeruleus was measured by immunohistochemistry. R maze and the Vogecreased the response of the anxiety-related behavior. The number of tyrosine hydroxylase-immunoreactive cells were also increased. The HT7 group showed a significant decrease of anxiety-related behavioral response, compared to the stress group. The tyrosine hydroxylase-immunoreactive expression was also decreased in the HT7 group. These findings suggestthat electroacupuncture to HT7 might play a role in reducing the stress-related responses, which may be helpful for the treatment of stress-related disorders.

• Journal of Ginseng Research
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• v.43 no.2
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• pp.326-334
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• 2019

Background: The objective of our study was to analyze the neuroprotective effects of ginsenoside derivatives Rb1, Rb2, Rc, Rd, Rg1, and Rg3 against glutamate-mediated neurotoxicity in HT22 hippocampal mouse neuron cells. Methods: The neuroprotective effect of ginsenosides were evaluated by measuring cell viability. Protein expressions of mitogen-activated protein kinase (MAPK), Bcl2, Bax, and apoptosis-inducing factor (AIF) were determined by Western blot analysis. The occurrence of apoptotic and death cells was determined by flow cytometry. Cellular level of $Ca^{2+}$ and reactive oxygen species (ROS) levels were evaluated by image analysis using the fluorescent probes Fluor-3 and 2',7'-dichlorodihydrofluorescein diacetate, respectively. In vivo efficacy of neuroprotection was evaluated using the Mongolian gerbil of ischemic brain injury model. Result: Reduction of cell viability by glutamate (5 mM) was significantly suppressed by treatment with ginsenoside Rb2. Phosphorylation of MAPKs, Bax, and nuclear AIF was gradually increased by treatment with 5 mM of glutamate and decreased by co-treatment with Rb2. The occurrence of apoptotic cells was decreased by treatment with Rb2 ($25.7{\mu}M$). Cellular $Ca^{2+}$ and ROS levels were decreased in the presence of Rb2, and in vivo data indicated that Rb2 treatment (10 mg/kg) significantly diminished the number of degenerated neurons. Conclusion: Our results suggest that Rb2 possesses neuroprotective properties that suppress glutamate-induced neurotoxicity. The molecular mechanism of Rb2 is by suppressing the MAPKs activity and AIF translocation.

• The Korea Journal of Herbology
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• v.34 no.4
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• pp.9-18
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• 2019

Objectives : It has been known to be correlated between phlegm and dementia from the perspective of oriental medicine, but it is unexplored whether herbal medicines to treat phlegm have pharmacological actions on Alzheimer's disease (AD). The aim of this study was to evaluate and to compare effects of herbal medicines to treat phlegm against AD in vitro. Methods : We selected 11 herbal medicines which treat phlegm and obtained each extract by boiling in 10-fold distilled water for 2 h. And we performed the assay of acetylcholinesterase (AChE) inhibitory effects of 11 herbal extracts. Next, we evaluated neuroprotective effects of them against amyloid $beta_{25-35}$ ($A{\beta}_{25-35}$) plaque-induced toxicity in HT22 mouse hippocampal neuronal cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. To investigate whether they show the anti-inflammatory effects against lipopolysaccharide (LPS), we also measured the levels of nitric oxide (NO) in BV2 microglia cells using griess reagent assay. Results : We found that Gamiyeongsin-hwan (GYH) and Cheonghunhwadam-tang (CHT) exhibited remarkable AChE inhibitory effects. In HT22 cells, Arisaematis Rhizoma, Trichosanthis Semen and Fritillariae Thunbergii Bulbus suppressed $A{\beta}_{25-35}$ plaque-induced neuronal cell death. In BV2 cells, Cheongung-hwan significantly inhibited the increase of NO contents induced by LPS and GYH and CHT showed a tendency to inhibit LPS-induced NO generation. Conclusions : These results suggest that several herbal medicines to treat phlegm showed the significant effects on AChE inhibition, neuroprotection against $A{\beta}_{25-35}$ plaque-induced toxicity, and inhibition of NO generation. Therefore, we demonstrate the possibility that herbal medicines with treating phlegm has effects against AD.

• Journal of Life Science
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• v.26 no.4
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• pp.475-483
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• 2016

The current study was conducted to evaluate beneficial effects of a new formula (CWC-9) using four traditional Oriental medicinal herbs, Cynanchum wilfordii, Rehmannia glutinosa, Polygala tenuifolia, and Acorus gramineus, on hippocampal cells and memory function. To examine the neuroprotective effects of a new four-herb extract, cell viability, cytotoxicity, and reactive oxygen species (ROS) assays were performed in HT22 cells and behavioral tests (Morris water maze and passive avoidance retention), Western blot, and immunohistochemistry were performed in a mouse model of focal cerebral ischemia. In HT22 hippocampal cells, pretreatment with CWC-9 resulted in significantly reduced glutamate-induced cell death with suppression of ROS accumulation caused by glutamate. In a mouse model of focal cerebral ischemia, we observed significant improvement of spatial and short-term memory function by treatment with CWC-9. Phosphorylated p38 mitogen-activated protein kinases (MAPK) in hippocampus of ischemic mice were decreased by treatment with CWC-9, but phosphorylated phosphatidylinositol-3 kinase (PI3K) and cAMP response element binding protein (CREB) were significantly enhanced. By immunohistochemical analysis, we confirmed higher expression of phosphorylation of CREB in the hippocampal neurons of CWC-9 treated mice. These results suggest that new multi-herb formula CWC-9 mainly exerted beneficial effects on cognitive function through regulation of neuro-protective signaling pathways associated with CREB.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.543-548
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• 2018

The current study examined antioxidant and neuronal cell protective effects of the crude polysaccharide fraction in Cudrania tricuspidata fruits (CTP). The radical scavenging activities of (1,1-diphenyl-picrylhydrazyl and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) and reducing power and FRAP of CTP were increased dose-dependently. In addition, the expression of neuroprotective effect of CTP was tested in HT22 mouse hippocampal cells. CTP treatment exhibited non cytotoxicity at dose levels below $500{\mu}g/mL$. Within this optimal concentration range, CTP treatment significantly increased cell viability in $H_2O_2-treated$ HT22 cells. Furthermore, CTP treatment increased superoxide dismutase (SOD) activity and decreased malonaldehyde (MDA) levels in HT22 cells. Therefore, these results indicate that the crude polysaccharide fraction from Cudrania tricuspidata fruits (CTP) possesses antioxidant activities and displays therapeutic potential as a useful source material in the development of brain disorder treatments targeting oxidative stress in neuronal cells.

• Biomolecules & Therapeutics
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• v.29 no.3
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• pp.321-330
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• 2021

Oxidative stress plays a crucial role in the development of neuronal disorders including brain ischemic injury. Thioredoxin 1 (Trx1), a 12 kDa oxidoreductase, has anti-oxidant and anti-apoptotic functions in various cells. It has been highly implicated in brain ischemic injury. However, the protective mechanism of Trx1 against hippocampal neuronal cell death is not identified yet. Using a cell permeable Tat-Trx1 protein, protective mechanism of Trx1 against hydrogen peroxide-induced cell death was examined using HT-22 cells and an ischemic animal model. Transduced Tat-Trx1 markedly inhibited intracellular ROS levels, DNA fragmentation, and cell death in H2O2-treatment HT-22 cells. Tat-Trx1 also significantly inhibited phosphorylation of ASK1 and MAPKs in signaling pathways of HT-22 cells. In addition, Tat-Trx1 regulated expression levels of Akt, NF-κB, and apoptosis related proteins. In an ischemia animal model, Tat-Trx1 markedly protected hippocampal neuronal cell death and reduced astrocytes and microglia activation. These findings indicate that transduced Tat-Trx1 might be a potential therapeutic agent for treating ischemic injury.