• Journal of Ginseng Research
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• v.46 no.4
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• pp.572-584
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• 2022

Background: Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of trinucleotide CAG repeat in the Huntingtin (Htt) gene. The major pathogenic pathways underlying HD involve the impairment of cellular energy homeostasis and DNA damage in the brain. The protein kinase ataxia-telangiectasia mutated (ATM) is an important regulator of the DNA damage response. ATM is involved in the phosphorylation of AMP-activated protein kinase (AMPK), suggesting that AMPK plays a critical role in response to DNA damage. Herein, we demonstrated that expression of polyQ-expanded mutant Htt (mHtt) enhanced the phosphorylation of ATM. Ginsenoside is the main and most effective component of Panax ginseng. However, the protective effect of a ginsenoside (compound K, CK) in HD remains unclear and warrants further investigation. Methods: This study used the R6/2 transgenic mouse model of HD and performed behavioral tests, survival rate, histological analyses, and immunoblot assays. Results: The systematic administration of CK into R6/2 mice suppressed the activation of ATM/AMPK and reduced neuronal toxicity and mHTT aggregation. Most importantly, CK increased neuronal density and lifespan and improved motor dysfunction in R6/2 mice. Conversely, CK enhanced the expression of Bcl2 protected striatal cells from the toxicity induced by the overactivation of mHtt and AMPK. Conclusions: Thus, the oral administration of CK reduced the disease progression and markedly enhanced lifespan in the transgenic mouse model (R6/2) of HD.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.327-334
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• 2020

Oxidative stress is common cause of neurodegenerative diseases. The purpose of this study is to investigate the in vitro free radical scavenging activity and protective effect of three Glycyrrhiza species including Glycyrrhiza uralensis, G. glabra, and a new variety of Glycyrrihza (Shinwongam, SW) against hydrogen peroxide-induced oxidative stress in C6 glial cells. In vitro assays, radical scavenging activities of G. uralensis, G. glabra, and SW against 2,2-diphenyl-1-picrylhydrazyl, ·OH, and O2- increased as concentration-dependent manner. In addition, the SW was found to contain the highest polyphenol and flavonoid contents. The treatment of H2O2 to C6 glial cell induced oxidative stress, whereas G. uralensis, G. glabra, and SW significantly increased the cell viability as dose-dependent manner. In particular, SW exerted stronger protective effect on H2O2-induced cytotoxicity, than G. uralensis and G. glabra. Furthermore, reactive oxygen species (ROS) formation was significantly elevated by H2O2 in C6 glial cells. However, treatments of G. uralensis, G. glabra, and SW decreased ROS formation. In addition, SW decreased pro-inflammatory related protein expression levels such as inducible nitric oxide synthase and cyclooxygenase-2, compared to H2O2-treated control group. These results indicated that G. uralensis and G. glavra, especially SW, may be useful for preventing from oxidative stress-induced neuronal damage by regulating inflammatory reaction.

• Clinical and Experimental Pediatrics
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• v.52 no.5
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• pp.588-593
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• 2009

Purpose : To investigate whether growth hormone (GH) has a protective effect on neurons in hippocampal slice cultures of neonatal rats exposed to oxygen-glucose deprivation (OGD). Methods : Cultured hippocampal slices of 7-day-old rats were exposed to OGD for 60 min. Then, the slices were immediately treated with three doses of GH (5, 50, or $500{\mu}M$) in media. The relative fluorescent densities of propidium iodide (PI) uptake in the slices and relative lactate dehydrogenase (LDH) activities in the media were determined and compared between each GH- treated group of slices and untreated slices (control) at 12 and 24 h after OGD. Immunofluorescent staining for caspase-3 and TUNEL staining were performed to observe the effect of GH on apoptotic neuronal death. Results : The relative fluorescent densities of PI uptake in CA1 and dentate gyrus (DG) of the hippocampal slices in each GH-treated group were not significantly different from those in the untreated slices at 12 and 24 h after OGD (P>0.05). Treatment with GH could reduce the relative LDH activities in the media of the GH-treated groups only at 12 h after OGD (P<0.05). Expression of caspase-3 and TUNEL positivity in CA1 and DG of the slices treated with 50-iM GH were not different from those of the untreated slices at 12 and 24 h after OGD. Conclusion : Treatment of hippocampal slice cultures with GH after OGD does not show a definitive protective effect on neuronal death but can reduce the LDH efflux of the slices in media at 12 h after OGD.

• Herbal Formula Science
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• v.25 no.1
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• pp.51-68
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• 2017

Objectives : Oxidative stress due to excessive accumulation of reactive oxygen species (ROS) is one of the risk factors for the development of several chronic diseases, including neurodegenerative diseases. Methods : In the present study, we investigated the protective effects of cheongnoemyeongsin-hwan (CNMSH) against oxidative stress‑induced cellular damage and elucidated the underlying mechanisms in neuronal-derived SH-SY5Y cells. Results : Our results revealed that treatment with CNMSH prior to hydrogen peroxide (H2O2) exposure significantly increased the SH-SY5Y cell viability, indicating that the exposure of the SH-SY5Y cells to CNMSH conferred a protective effect against oxidative stress. CNMSH also effectively attenuated H2O2‑induced comet tail formation, and decreased the phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V‑positive cells. In addition, CNMSH exhibited scavenging activity against intracellular ROS generation and restored the mitochondria membrane potential (MMP) loss that were induced by H2O2, suggesting that CNMSH prevents H2O2‑induced DNA damage and cell apoptosis. Moreover, H2O2 enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with CNMSH. Furthermore, CNMSH increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). According to our data, CNMSH is able to protect SH-SY5Y cells from H2O2-induced apoptosis throughout blocking cellular damage related to oxidative stress through a mechanism that would affect ROS elimination and activating Nrf2/HO-1 signaling pathway. Conclusions : Therefore, we believed that CNMSH may potentially serve as an agent for the treatment and prevention of neurodegenerative diseases caused by oxidative stress.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.87-92
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• 2009

The antioxidant properties and protective effects of Inula britannica on ${H_2}{O_2}$-induced SH-SY5Y neuroblastoma cell damage were investigated. A series of solvent fractions, including hexane(Fr.H), petroleum ether, chloroform, ethyl acetate(Fr.EA), and water fraction(Fr.W), were prepared from the 70% methanol extracts of Inula britannica. Fr.W had the highest total contents of phenolics and flavonoids, followed by Fr.EA. The antioxidant properties of the fractions were also evaluated by analyzing their scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radicals, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, and nitric oxide. Fr.W showed the strongest activities in all assays. The concentrations of Fr.W that resulted in 50% reductions of the DPPH and ABTS radicals were 20.7 ${\mu}g$/mL and 39.4 ${\mu}g$/mL, respectively. Fr.W showed the weakest cytotoxic activities on the SH-SY5Y cells, whereas it effectively protected ${H_2}{O_2}$-induced cell death, increasing cell survival by 35.0-77.0% at a concentration range of 62.5-250 ${\mu}g$/mL. In this range, Fr.W also significantly decreased intracellular ROS levels by 34-39%. Overall, the antioxidant properties of Inula britannica can contribute to rescuring neuronal cells from oxidative stress-induced cell injury.

• The Journal of Korean Medicine
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• v.31 no.2
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• pp.1-18
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• 2010

Objective: The water extract of Chilgi-tang (CGT) has been traditionally used in treatment of heart diseases caused by stress in Oriental Medicine. However, little is known about the mechanism by which CGT rescues neuronal cells from injury damage. Therefore, this study was designed to evaluate the protective effects of CGT on Neuro-2A cells by glucose deprivation-induced cell death. Methods: We investigated how cell death induced by glucose deprivation was associated with increased reactive oxygen species (ROS) generation. Result: The CGT treatment prior to glucose deprivation insult significantly reduced the number of cell deaths and the glucose deprivation-induced increase in ROS. Nitric oxide (NO) was also attenuated by CGT treatment. In addition, we demonstrated that the anti-cell death effect of CGT was blocked by heme oxygenase-1 (HO-1) activation. Finally, pretreatment of cells with a hemin, HO-1 inducer, reduced glucose deprivation-induced cell death. In contrast, pretreatment of cells with a ZnPP, HO-1 activity inhibitor, attenuated CGT-induced inhibition of cell death. Conclusions: These findings indicate that ROS plays an important role in glucose deprivation-induced cell death and that CGT may prevent glucose deprivation-induced cell death by inhibiting the ROS generation through HO-1 activation in Neuro-2A cells.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.3
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• pp.301-309
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• 2018

Statins mediate vascular protection and reduce the prevalence of cardiovascular diseases. Recent work indicates that statins have anticonvulsive effects in the brain; however, little is known about the precise mechanism for its protective effect in kainic acid (KA)-induced seizures. Here, we investigated the protective effects of atorvastatin pretreatment on KA-induced neuroinflammation and hippocampal cell death. Mice were treated via intragastric administration of atorvastatin for 7 days, injected with KA, and then sacrificed after 24 h. We observed that atorvastatin pretreatment reduced KA-induced seizure activity, hippocampal cell death, and neuroinflammation. Atorvastatin pretreatment also inhibited KA-induced lipocalin-2 expression in the hippocampus and attenuated KA-induced hippocampal cyclooxygenase-2 expression and glial activation. Moreover, AKT phosphorylation in KA-treated hippocampus was inhibited by atorvastatin pretreatment. These findings suggest that atorvastatin pretreatment may protect hippocampal neurons during seizures by controlling lipocalin-2-associated neuroinflammation.

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.282-287
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• 2003

We reported that neurotoxicity may contribute to cyanide-induced neuronal injury. Cyanide stimulates the release of glutamate which can activate glutamate receptors to propagate excitotoxic processes. We examined the role of plant extracts in mediating the cyanide-induced cytotoxicity and report here that the cytotoxicity assessed in SK- N-SH cell cultures by measuring lactate dehydrogenase (LDH) in the culture media was significantly blocked by Evodia officinalis MeOH extract (OMU). Also, when OMU was treated in NaCN level cultures, the neurite outgrowth was regenerated as much as in the treatment of NaCN only. These results indicate that OMU treatment were not only protected the neurons against NaCN-induced damage but also regenerated the neurite outgrowth of neuroblastoma cells.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.04a
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• pp.123-135
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• 2006

Alzheimer's disease (AD) is the most common form of dementia in the aging population and is clinically characterized by a progressive loss of cognitive abilities. Pathologically, it is defined by the appearance of senile plaques - extracellular insoluble, congophilic protein aggregates composed of amyloid $\beta$ (A$\beta$) and neurofibrillary tangles (NFTs) - inyracellular lesions consisting of paired helical filaments from hyperphosphorylated cytoskeletal tau protein as described by Alois Alzheimer a century ago. These hallmarks still serve as the major criteria for a definite diagnosis of the disease. Consequently, one of the key strategy for drug development in this disease area focuses on reducing the concentration of cerebral A$\beta$ plaque by using substances that inhibit A$\beta$ fibril formation. We focused on developing inhibitors by synthesizing several kinds of aromatic molecules. The synthetic compounds were initially screened to evaluate the effective compound by tioflavin T fluorescence assay. The selected effective compounds were tested cytotoxicity and protective effect from A$\beta$-induced neuronal toxicity by cell based MTT assay with HT22 hippocampal neurons. The BBB permeability on effectors was also tested in in vitro co-culture model(HUVEC/C6 cell line). The behavior test wea carried out in mutant APP/PS1 transgenic mouse model of Alzheimer's disease. And inhibition of A$\beta$ fibril formation by the effective compound was monitored with transmitted electron microscopic images.

• The Journal of Korean Medicine
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• v.23 no.1
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• pp.50-60
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• 2002

Objectives: Sunghyangjunggisan (SHJS) is a commonly prescribed drug with a wide neuropharmacological spectrum. The water extracts of SHJS were found to be protective against neurotoxicity elicited by deprivation of serum and glucose. Methods: The morphological examination and Hoechst staining of nucleus also clearly showed that the extracts attenuated the cell shrinkage, membrane blebbing, representing typical neuronal apoptotic phenomena and nucleosome-sized fragmentation under the microscope in PC 12 rat pheochromocytoma cells. Results: Activation of protein kinase A (PKA) with dibutyl-cAMP and forskolin also protected during glucose deprivation, although it was not additive with the effect provided by phorbol ester. Interestingly, treatment with the protein kinase A inhibitor, KT5720, was not neuroprotective in the presence of SHJS. Electrophoretic mobility shift assays were used to characterize the neuroprotective binding of nuclear proteins to consensus sequences for AP-l, nuclear factor kappa B ($NF-{\kappa}B$) after glucose deprivation. When PC 12 cells are induced to undergo apoptosis by serum deprivation, AP-l and $NF-{\kappa}B$ DNA binding activity transiently increases to a slight degree. This stimulation is blocked by the water extracts of SHJS. The site of action of the drugs appeared to involve specific inhibition of AP-1 and nuclear factor kB binding activity. Conclusions: Taken together, these results suggested the possibility that the extracts of SHJS might provide a neurotrophic-like activity in PC 12 cells.