• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.425-430
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• 2011

In this study, we found that Forsythiae fructus (FF) and one of its main compounds, arctigenin, significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Arctigenin also suppressed the expression of inducible nitric oxide synthase and cyclooxygenase-2, and inhibited the activation of extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38. Moreover, it also reduced levels of proinflammatory cytokines, interleukin $1{\beta}$, tumor necrosis factor ${\alpha}$ and prostaglandin E2, and inhibited neuronal death in LPS-treated organotypic hippocampal cultures. Therefore, we suggest that arctigenin may confer a neuroprotective effect via the inhibition of neuroinflammation.

• Korean Journal of Pharmacognosy
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• v.50 no.2
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• pp.118-123
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• 2019

Glutamate acts as an important neurotransmitter in brain. However, high concentration of glutamate showed an excitatory neurotoxicity and resulted to neuronal cell death. Neuronal cell death is known for one of the reason of Alzheimer's disease, a neurodegenerative disease. We tried to find neuroprotective medicinal plants by neuroprotection activity against glutamate injured HT22 cells as a model system. In the course of bioscreening of various medicinal plants, Taraxacum platycarpum extract showed significant neuroprotective activity. We tried to elucidate mechanisms of neuroprotective activity. T. platycarpum extract reduced ROS and intracellular $Ca^{2+}$ concentration increased by glutamate induced neurotoxicity. In addition, mitochondrial membrane potential was restored to the control level. Also, glutathione level, glutathione reductase and glutathione peroxidase activity were increased by T. platycarpum extract treatment. These data suggested that T. platycarpum showed neuroprotective activity via antioxidative activity.

• Journal of Pharmacopuncture
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• v.21 no.4
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• pp.226-240
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• 2018

Neuroprotection or prevention of neuronal loss is a complicated molecular process that is mediated by various cellular pathways. Use of different pharmacological agents as neuroprotectants has been reported especially in the last decades. These neuroprotective agents act through inhibition of inflammatory processes and apoptosis, attenuation of oxidative stress and reduction of free radicals. Control of this injurious molecular process is essential to the reduction of neuronal injuries and is associated with improved functional outcomes and recovery of the patients admitted to the intensive care unit. This study reviews neuroprotective agents and their mechanisms of action against central nervous system damages.

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.247.2-247.2
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• 2003

• Biomedical Science Letters
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• v.23 no.1
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• pp.17-24
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• 2017

Estrogens are effective neuroprotectants in vivo and in vitro. To obtain a better insight into the molecular mechanisms of action of neuroprotection by $17{\beta}-estradiol$ (E2), we examined the differential effects of E2 on the fluidity of synaptosomal plasma membrane vesicles (SPMV) isolated from rat cerebral cortex. Intramolecular excimerization of 1,3-di(1-pyrenyl)-propane (Py-3-Py) was used to investigate the effects of E2 on the bulk and annular lateral diffusion of the SPMV. In addition, we examined the effects of E2 on the rotational diffusion of individual leaflet of SPMV exploiting selective quenching of outer monolayer 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence by trinitrophenyl groups. The $F{\ddot{o}}rster$ distance $R_0$ value for the tryptophan-Py-3-Py donor-acceptor pair was $26.9{\AA}$. E2 increased the lateral mobility of both bulk and annular lipids in SPMV in a dose-dependent manner, but a larger effect on bulk lipids was observed. Although E2 decreased the anisotropy of DPH in SPMV, E2 had a greater fluidizing effect on the outer leaflet compared to the inner leaflet. These results suggest that E2 selectively fluidizes the more fluid regions within SPMV. It is highly probable that E2 mostly fluidizes the bulk lipids, away from either annular lipids or lipid rafts, in the outer leaflet of SPMV. This selective fluidization may be one of the nongenomic mechanisms of neuroprotection by E2.

• Biomolecules & Therapeutics
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• v.24 no.5
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• pp.495-500
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• 2016

This study aimed to explore the neuroprotection and mechanism of isoflurane on rats with spinal cord ischemic injury. Total 40 adult male Sprague-Dawley rats were divided into the four groups (n=10). Group A was sham-operation group; group B was ischemia group; group C was isoflurane preconditioning group; group D was isoflurane preconditioning followed by ischemia treatment group. Then the expressions of TWIK-related $K^+$ channel 1 (TREK1) in the four groups were detected by immunofluorescent assay, real time-polymerase chain reactions (RT-PCR) and western blot. The primary neurons of rats were isolated and cultured under normal and hypoxic conditions. Besides, the neurons under two conditions were transfected with green fluorescent protein (GFP)-TREK1 and lentivirual to overexpress and silence TREK1. Additionally, the neurons were treated with isoflurane or not. Then caspase-3 activity and cell cycle of neurons under normal and hypoxic conditions were detected. Furthermore, nicotinamide adenine dinucleotide hydrate (NADH) was detected using NAD+/NADH quantification colorimetric kit. Results showed that the mRNA and protein expressions of TREK1 increased significantly in group C and D. In neurons, when TREK1 silenced, isoflurane treatment improved the caspase-3 activity. In hypoxic condition, the caspase-3 activity and sub-G1 cell percentage significantly increased, however, when TREK1 overexpressed the caspase-3 activity and sub-G1 cell percentage decreased significantly. Furthermore, both isoflurane treatment and overexpression of TREK1 significantly decreased NADH. In conclusion, isoflurane-induced neuroprotection in spinal cord ischemic injury may be associated with the up-regulation of TREK1.

• Annals of Clinical Neurophysiology
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• v.8 no.1
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• pp.63-70
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• 2006

Background: Testosterone is reported to have neuroprotective effect in various neurological diseases. Recently, the mechanism involved in nitric oxide (NO)-mediated motor neuron death is under extensive investigation. The Cu/Zn-superoxide dismutase (SOD1) mutations has been implicated in selective motor neuron death of amyotrophic lateral sclerosis (ALS) and it is said to play an important role in NO-mediated motor neuron death. However, neuroprotective effect of testosterone on motor neuron exposed to NO has rarely been studied. Methods: Motor neuron-neuroblastoma hybrid cells expressing wild-type or mutant (G93A or A4V) SOD gene were treated with $200{\mu}M$ S-nitrosoglutathione. After 24 hr, cell viability was measured by MTT assay. To see the neuroprotective effect of testosterone, pretreatment with 1 nM testosterone was done 1 hr before S-nitroglutathione treatment. To study the mechanism of protective effect, $20{\mu}M$ flutamide (androgen receptor antagonist) was also pretreated with testosterone 1 hr before S-nitroglutathione treatment. Results: S-nitrosoglutathione showed significant neurotoxic effect in all three cell lines. Percentage of cell death was somewhat different in each cell line. 1 nM testosterone showed neuroprotective effect in G93A and wild-type cell line. In A4V cell line, testosterone did not showed neuroprotective effect. The neuroprotective effect of testosterone was reversed by $20{\mu}M$ flutamide. Conclusions: These results indicate that testosterone induces neuroprotection in NO-mediated motor neuron death directly through the androgen receptor. This neuroprotective effect of testosterone varies according to the types of SOD1 gene mutation. These data suggest that testosterone may be of therapeutic value against ALS.

• Korean Journal of Pharmacognosy
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• v.53 no.4
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• pp.192-201
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• 2022

This study aimed to compare bioactivities of Centella asiatica (CA) cultivated in smart farms and fields. Component analysis, cell viability, anti-inflammatory activity, neuroprotection activity, and antioxidant activity were examined with 70% ethanol extracts of CA cultivated in smart farm (SEE) and field (FEE), respectively. Asiaticoside was analyzed by high performance liquid chromatography (HPLC) and as a result, SEE had more asiaticoside content than FEE. After treatment of RAW 264.7 cells with SEE and FEE, there was no cytotoxicity within the treated concentrations. SEE and FEE showed nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 inhibitory activities in a dose-dependent manner in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Moreover, SEE inhibited more NO, TNF-α, and IL-6 production levels than FEE. SEE and FEE reversed the H₂O₂-induced SH-SY5Y cell death. Especially, SEE was more effective in changing the H₂O₂-induced SH-SY5Y cell death than FEE. The antioxidant activity was confirmed by various methods such as total phenol content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide dismutase (SOD). As a result, SEE showed the most potent antioxidant activities about TPC, DPPH, and SOD methods. This study suggested that SEE has higher bioactivities such as effect of anti-inflammation, neuroprotection, and antioxidation than FEE.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2017.10a
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• pp.212-212
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• 2017

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.69-69
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• 2003

Neuroprotective strategies have been appeared to be effective in a variety of stroke models. One of the major focuses has been related to the activities of estrogen. $17\beta$-estradiol valerate(EV) has been reported to exert neuroprotective effects when administered before an ischemic insult. The purpose of this study was to determine whether EV can protect against brain injury via estrogen receptor. Chronic and acute pretreatment can reduce the ischemic damage of focal cerebral ischemia in OVX rat, indicating that EV may be a new therapeutic class of drugs to prevent neuronal damage associated with cerebral ischemia. RNAs were extracted from the hippocampus of ovariectomized female rat with or without EV. Differential gene expression profiles were revealed(Bone morphogenetic protein type 1A receptor, Protein disulphide isomerase, cytochrome bc-1 complex core P, thiol-specific antioxidant protein). RT-PCR and in situ hybridization were used to validate the relative expression pattern obtained by the cDNA array. This Study was supported by the Korea Science and Engineering Foundation(KOSEF) through the Biohealth Products Research Center(BPRC), Inje University, Korea