• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1459-1466
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• 2006

The water extract of Hwansodan has been traditionally used for treatment of ischemic brain damage in oriental medicine. However, little is known about the mechanism by which the water extract of Hwansodan rescues cells from neurodegenerative disease. PC12 pheochromocytoma cells have been used extensively as a model for studying the cellular and molecular mechanisms of neuronal cell damages. Under deprivation of growth factor and ischemic injury, PC12 cells spontaneously undergoes apoptotic cell death. Serum and glucose deprivation markedly decreased the viability of PC12 cells, which was characterized with apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the aqueous extract of Hwansodan significantly reduced serum and glucose deprivation-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Pretreatment of Hwansodan also ingibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 was completely abolished in serum and glucose deprivated cells. Furthermore, pretreatment of Hwansodan obviously increased heme oxygenase 1 (HO-1) expression in PC12 cells. Taken together, the data suggest that the protective effects of Hwansodan against serum and glucose deprivation induced oxidative injuries may be achieved through the scavenging of reactive oxygene species accompanying with HO-1 induction.

• BMB Reports
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• v.52 no.7
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• pp.439-444
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• 2019

Although hypoxic/ischemic injury is thought to contribute to the incidence of Alzheimer's disease (AD), the molecular mechanism that determines the relationship between hypoxia-induced ${\beta}$-amyloid ($A{\beta}$) generation and development of AD is not yet known. We have now investigated the protective effects of N,4,5-trimethylthiazol-2-amine hydrochloride (KHG26702), a novel thiazole derivative, on oxygen-glucose deprivation (OGD)-reoxygenation (OGD-R)-induced $A{\beta}$ production in SH-SY5Y human neuroblastoma cells. Pretreatment of these cells with KHG26702 significantly attenuated OGD-R-induced production of reactive oxygen species and elevation of levels of malondialdehyde, prostaglandin $E_2$, interleukin 6 and glutathione, as well as superoxide dismutase activity. KHG26702 also reduced OGD-R-induced expression of the apoptotic protein caspase-3, the apoptosis regulator Bcl-2, and the autophagy protein becn-1. Finally, KHG26702 reduced OGD-R-induced $A{\beta}$ production and cleavage of amyloid precursor protein, by inhibiting secretase activity and suppressing the autophagic pathway. Although supporting data from in vivo studies are required, our results indicate that KHG26702 may prevent neuronal cell damage from OGD-R-induced toxicity.

• Molecules and Cells
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• v.42 no.1
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• pp.36-44
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• 2019

Alzheimer's disease (AD) is the most frequent age-related human neurological disorder. The characteristics of AD include senile plaques, neurofibrillary tangles, and loss of synapses and neurons in the brain. ${\beta}-Amyloid$ ($A{\beta}$) peptide is the predominant proteinaceous component of senile plaques. The amyloid hypothesis states that $A{\beta}$ initiates the cascade of events that result in AD. Amyloid precursor protein (APP) processing plays an important role in $A{\beta}$ production, which initiates synaptic and neuronal damage. ${\delta}-Catenin$ is known to be bound to presenilin-1 (PS-1), which is the main component of the ${\gamma}-secretase$ complex that regulates APP cleavage. Because PS-1 interacts with both APP and ${\delta}-catenin$, it is worth studying their interactive mechanism and/or effects on each other. Our immunoprecipitation data showed that there was no physical association between ${\delta}-catenin$ and APP. However, we observed that ${\delta}-catenin$ could reduce the binding between PS-1 and APP, thus decreasing the PS-1 mediated APP processing activity. Furthermore, ${\delta}-catenin$ reduced PS-1-mediated stabilization of APP. The results suggest that ${\delta}-catenin$ can influence the APP processing and its level by interacting with PS-1, which may eventually play a protective role in the degeneration of an Alzheimer's disease patient.

• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.119-131
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• 2021

Over-produced reactive oxygen species (ROS) exert oxidative damage on lipids, proteins, and DNA in the human body, which leads to the onset of neurodegenerative diseases such as Alzheimer's disease (AD). In this study, we explored the cellular antioxidant effect of Cirsium japonicum var. maackii (CJM) against hydrogen peroxide (H₂O₂)-induced oxidative stress in neuronal cells. The antioxidant activity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, 2',7'-dichlorofluorescin diacetate and nitric oxide (NO) assays, and the molecular mechanisms were examined by Western blot analysis. H₂O₂ treatment of SH-SY5Y cells decreased cell viability and increased ROS and NO production compared to H₂O₂-untreated cells. However, CJM increased cell viability and decreased ROS and NO accumulation in the H₂O₂-treated SH-SY5Y cells compared to H₂O₂-treated control cells. Especially, the EtOAc fraction from CJM showed the strongest antioxidant effect compared with the other extracts and fractions. Therefore, we further examined the CJM mechanism against oxidative stress using the EtOAc fraction from CJM. The EtOAc fraction up-regulated the expressions of heme oxygenase-1, NAD(P)H quinone oxidoreductase 1, and thioredoxin reductase 1. These results indicate that CJM promotes the activation of antioxidative enzymes, which eliminate ROS and NO, and further leads to an increase in the cell viability. Taken together, our results show that CJM exhibited an antioxidant activity in H₂O₂-treated SH-SY5Y cells, and it could be a novel antioxidant agent for the prevention or treatment of neurodegenerative disease such as AD.

• Sleep Medicine and Psychophysiology
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• v.28 no.1
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• pp.18-26
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• 2021

Sleep is essential to brain function and mental health. Insomnia and obstructive sleep apnea (OSA) are the two most common sleep disorders, and are major public health concerns. Proton magnetic resonance spectroscopy (¹H-MRS) is a non-invasive method of quantifying neurometabolite concentrations. Therefore, ¹H-MRS studies on individuals with sleep disorders may enhance our understanding of the pathophysiology of these disorders. In this article, we reviewed ¹H-MRS studies in insomnia and OSA that reported changes in neurometabolite concentrations. Previous studies have consistently reported insomnia-related reductions in γ-aminobutyric acid (GABA) levels in the frontal and occipital regions, which suggest that changes in GABA are important to the etiology of insomnia. These results may support the hyperarousal theory that insomnia is associated with increased cognitive and physiological arousal. In addition, the severity of insomnia was associated with low glutamate and glutamine levels. Previous studies of OSA have consistently reported reduced N-acetylaspartate (NAA) levels in the frontal, parieto-occipital, and temporal regions. In addition, OSA was associated with increased myo-inositol levels. These results may provide evidence that intermittent hypoxia induced by OSA may result in neuronal damage in the brain, which can be related to neurocognitive dysfunction in patients with OSA. The current review summarizes findings related to neurochemical changes in insomnia and OSA. Future well-designed studies using ¹H-MRS have the potential to enhance our understanding of the pathophysiology of sleep disorders including insomnia and OSA.

• Nutrition Research and Practice
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• v.16 no.2
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• pp.173-193
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• 2022

BACKGROUND/OBJECTIVES: Alzheimer's disease (AD) is one of the most representative neurodegenerative disease mainly caused by the excessive production of amyloid beta (Aβ). Several studies on the antioxidant activity and protective effects of Populus tomentiglandulosa (PT) against cerebral ischemia-induced neuronal damage have been reported. Based on this background, the present study investigated the protective effects of PT against cognitive impairment in AD. MATERIALS/METHODS: We orally administered PT (50 and 100 mg/kg/day) for 14 days in an Aβ_25-35-induced mouse model and conducted behavioral experiments to test cognitive ability. In addition, we evaluated the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum and measured the production of lipid peroxide, nitric oxide (NO), and reactive oxygen species (ROS) in tissues. RESULTS: PT treatment improved the space perceptive ability in the T-maze test, object cognitive ability in the novel object recognition test, and spatial learning/long-term memory in the Morris water-maze test. Moreover, the levels of AST and ALT were not significantly different among the groups, indicating that PT did not show liver toxicity. Furthermore, administration of PT significantly inhibited the production of lipid peroxide, NO, and ROS in the brain, liver, and kidney, suggesting that PT protected against oxidative stress. CONCLUSIONS: Our study demonstrated that administration of PT improved Aβ_25-35-induced cognitive impairment by regulating oxidative stress. Therefore, we propose that PT could be used as a natural agent for AD improvement.

• Journal of the Korean Society of Food Culture
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• v.37 no.6
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• pp.503-509
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• 2022

Methylglyoxal is a highly reactive precursor which forms advanced glycation end products (AGEs). AGEs and methylglyoxal are known to induce various diseases such as diabetes, vascular disorders, Diabetes Mellitus (DM), and neuronal disorders. Juglans regia L is an important food commonly used worldwide, having nutritious components, including phenolic compounds. Since ancient times, Juglans regia L have been differently applied by various countries for health and in diverse diseases, including arthritis, asthma, skin disorders, cancer, and diabetes mellitus. However, the effect of diabetes-induced renal damage against AGEs remains unclear. This study evaluates the anti-glycation and renal protective effects of ethanol extract of Juglans regia L against methylglyoxal-induced renal tubular epithelial cell death. Exposure to methylglyoxal resulted in reduced cell viability in NRK-52E cells, but co-treatment with Juglans regia L extracts significantly increased the cell viability. In addition, we examined the anti-glycation effect of Juglans regia L extracts. Compared to the positive control aminoguanidine and Alagebrium, treatment with Juglans regia L extracts significantly inhibited the formation of AGEs, collagen cross-linking, and breaking collagen cross-linking. Taken together, our results indicate that Juglans regia L is a potential therapeutic agent for regulating diabetic complications by exerting anti-glycation and renal protective activities.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.79-86
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• 2013

Objectives : The purpose of this study is to investigate neuroprotective effects and molecular mechanisms of luteolin against ${\beta}$-amyloid ($A{\beta}_{25-35}$)-induced oxidative cell death in BV-2 cells. Methods : The protective effects of luteolin against $A{\beta}_{25-35}$-induced cytotoxicity and apoptotic cell death were determined by MTT dye reduction assay and TUNEL staining, respectively. The apoptotic cell death was further analyzed by measuring mitochondrial transmembrane potential and expression of pro- and/or anti-apoptotic proteins. To elucidate the molecular mechanisms underlying the protective effects of luteolin, intracellular accumulation of reactive oxygen species, oxidative damages, and expression of antioxidant enzymes were examined. Results : Luteolin pretreatment effectively attenuated $A{\beta}_{25-35}$-induced apoptotic cell death indices such as DNA fragmentation, dissipation of mitochondrial transmembrane potential, increased Bax/Bcl-2 ratio, and activation of c-Jun N-terminal kinase and caspase-3 in BV-2 cells. Furthermore, $A{\beta}_{25-35}$-induced intracellular formation of reactive oxygen species and subsequent oxidative damages such as lipid peroxidation and depletion of endogenous antioxidant glutathione were suppressed by luteolin treatment. The neuroprotective effects of luteolin might be mediated by up-regulation of cellular antioxidant defense system via up-regulation of ${\gamma}$-glutamylcysteine ligase, a rate-limiting enzyme in the glutathione biosynthesis and superoxide dismutase, an enzyme involved in dismutation of superoxide anion into oxygen and hydrogen peroxide. Conclusions : These findings suggest that luteolin has a potential to protect against $A{\beta}_{25-35}$-induced neuronal cell death and damages thereby exhibiting therapeutic utilization for the prevention and/or treatment of Alzheimer's disease.

• The Korea Journal of Herbology
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• v.28 no.5
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• pp.21-28
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• 2013

Objectives : The aim of this study was to investigate the neuroprotective effects and mechanisms of Cyperi Rhizoma extracts (CRE) using in vitro and in vivo models of Parkinson's disease (PD). Methods : We evaluated the neuroprotective effect of CRE against 1-methyl-4-phenylpyridinium (MPP+) toxicity using tyrosine hydroxylase immunohistochemistry (IHC) in primary rat mesencephalic dopaminergic neurons. In addition, the effect of CRE was evaluated in mice PD model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). For evaluations, C57bl/6 mice were orally treated with CRE 50 mg/kg for 5 days and were injected intraperitoneally with MPTP (20 mg/kg) at 2 h intervals on the last day. To identify the CRE affects on MPTP-induced neuronal loss of dopaminergic neurons in substantia nigra pars compacta (SNpc) and striatum of mice, the behavioral tests and IHC analysis were carried out. Also, we conducted nitric oxide (NO) and tumor necrosis factor-alpha (TNF-${\alpha}$) assay in dopaminergic neurons and IHC using glial markers in SNpc of mice to assess the anti-inflammation effects. Results : In primary mesencephalic culture system, CRE protected dopaminergic cells against $10{\mu}M$ MPP+-induced toxicity at 0.2 and $1.0{\mu}g/mL$. In the behavior tests, CRE treated group showed improved motor deteriorations than those in the MPTP only treated group. CRE significantly protected striatal dopaminergic damage from MPTP-induced neurotoxicity in mice. Moreover, CRE inhibited productions of NO and TNF-${\alpha}$ in dopaminergic culture system and activation of astrocyte and microglia in SNpc of the mice. Conclusion : We concluded that CRE shows anti-parkinsonian effect by protecting dopaminergic neurons against MPP+/MPTP toxicities through anti-inflammatory actions.

• Korean Journal of Veterinary Research
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• v.63 no.1
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• pp.6.1-6.9
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• 2023

Stroke is a major cause of death and long-term disability. Chlorogenic acid is a phenolic compound with a potent neuroprotective effect. γ-enolase is a phosphopyruvate hydratase found in mature neurons and plays an important role in neuronal survival. This study investigated whether chlorogenic acid regulates the expression of γ-enolase during cerebral ischemia. Middle cerebral artery occlusion (MCAO) was performed to induce cerebral ischemia. Adult male rats were used and chlorogenic acid (30 mg/kg) or phosphate buffered saline (PBS) was injected intraperitoneally 2 hours after MCAO surgery. Cerebral cortical tissues were collected 24 hours after MCAO surgery. Our proteomic approach identified the reduction of γ-enolase caused by MCAO damage and the mitigation of this reduction by chlorogenic acid treatment. Results of reverse transcription-polymerase chain reaction and Western blot analyses showed a decrease in γ-enolase expression in the PBS-treated MCAO group. However, chlorogenic acid treatment attenuated this decrease. Results of immunofluorescence staining showed the change of γ-enolase by chlorogenic acid treatment. These results demonstrated that chlorogenic acid regulates the γ-enolase expression during MCAO-induced ischemia. Therefore, we suggest that chlorogenic acid mediates the neuroprotective function by regulating the γ-enolase expression in cerebral ischemia and may be used as a therapeutic agent for brain diseases including stroke.