본 연구에서는 가물치(Channa argus) 추출물의 신경세포 분화와 산화 스트레스에서의 효능을 분석하기 위하여 녹차와 효소를 이용한 다양한 추출 방법(상온 추출물, RE; 녹차 상온 추출물, GRE; 효소 상온 추출물, ERE; 녹차 효소 상온 추출물, GERE)을 사용하여 제조 된 추출물의 아미노산 조성과 항산화 활성을 비교 분석하였고, 신경성장인자 (NGF) 유도 신경세포 분화 및 과산화수소 처리에 의해 유도된 PC12 세포 독성에 대한 보호효과를 규명하고자 하였다. 총 아미노산 함량은 RE 및 GRE보다 효소 추출물인 ERE 및 GERE에서 훨씬 더 높았다. 효소 가수 분해물 (ERE 및 GERE)에서 ABTS 라디칼 소거 활성은 RE 및 GRE보다 높았다. 또한, RE와 ERE는 PC12 세포에서 neuronal growth factor (NGF) 매개 신경 돌기 성장뿐만 아 니라 growth associated protein (GAP)-43 및 synapsin-1의 발현을 현저하게 향상 시켰다. 과산화수소(H2O2)에 의해 손 상된 PC12 세포에 4가지 유형의 Channa argus 추출물을 첨가한 후 PC12 세포의 생존율을 측정하였다. PC12 세포 의 생존율은 RE, GRE, GERE에서 각각 77.5±1.9%, 84.0±0.8%, 81.1±0.9%이였다. 이러한 세포 생존율은 H2O2 만을 처리 한 음성 대조군(70.0±2.0%)에 비해 더 높았다. H2O2 처리에 의해 유도 된 세포 독성도 RE, GRE 및 GERE 처리에 대한 반응으로 상당히 완화되었다. 종합하면, Channa argus 추출물은 산화 스트레스와 신경 손상을 감소시키는 기능성 물질로 유용하다는 것을 시사하며, 향후 이들 소재를 활용한 다양한 기능성 제품의 개발이 필요할 것으로 판단된다.

Alpha-lipoic acid (ALA) is a naturally occurring antioxidant and has been previously used to treat diabetes and cardiovascular disease. However, the autophagy effects of ALA against oxidative stress-induced dopaminergic neuronal cell injury remain unclear. The aim of this study was to investigate the role of ALA in autophagy and apoptosis against oxidative stress in the SH-SY5Y human dopaminergic neuronal cell line. We examined SH-SY5Y phenotypes using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (cell viability/proliferation), 4′,6-diamidino-2-phenylindole dihydrochloride nuclear staining, Live/Dead cell assay, cellular reactive oxygen species (ROS) assay, immunoblotting, and immunocytochemistry. Our data showed ALA attenuated hydrogen peroxide (H2O2)-induced ROS generation and cell death. ALA effectively suppressed Bax up-regulation and Bcl-2 and BclxL down-regulation. Furthermore, ALA increased the expression of the antioxidant enzyme, heme oxygenase-1. Moreover, the expression of Beclin-1 and LC-3 autophagy biomarkers was decreased by ALA in our cell model. Combined, these data suggest ALA protects human dopaminergic neuronal cells against H2O2-induced cell injury by inhibiting autophagy and apoptosis.

Cognitive impairment is considered to be key research topics in the field of neurodegenerative diseases and in understanding of learning and memory. In the present study, we investigated neuroprotective effects of Schisandra chinensis (SC) and Ribes fasciculatum (RF) extracts in hydrogen peroxide-induced neuronal cell death in vitro and scopolamine-induced cognitive impairment in Sprague Dawley® (SD) rat in vivo. Apoptotic cell death in neuroblastic PC12 cell line was induced by hydrogen peroxide for 1 hour at 100 μM. However, mixture of SC and RF treatment prevented peroxide induced PC12 cell death with no neurotoxic effects. For in vivo experiment, the effect of SC and RF extracts on scopolamine-induced cognitive impairment in SD rat was evaluated by spontaneous alternation behavior in Y-Maze test. After 30 min scopolamine injection, the scopolamine-induced rats presented significantly decreased % spontaneous alteration and acetylcholine level, compared to non-induced group. However, treatment of SC+RF extracts rescued the reduced % spontaneous alteration with acetylcholine concentration from hippocampus in scopolamineinduced rats. These results suggested that mixture of SC and RF extract may be a potential natural therapeutic agent for the prevention of cognitive impairment.

건조방법을 달리한 초석잠(Stachys sieboldii Miq.)을 열수 및 70% 에탄올 용매로 추출하여 제조한 후 추출물 농도에 따른 총 flavonoid 및 총 polyphenol 함량, DPPH radical 소거활성, ABTS radical 소거활성, 산화적 스트레스로부터의 신경세포 보호효과에 미치는 효과를 조사하기 위하여 실시 하였다. 초석잠 추출물들의 총 flavonoid와 총 polyphenol 함량은 동결건조 열수 추출물에서 각각 가장 높았다(p<0.05). DPPH 및 ABTS radical 소거활성은 농도의존적으로 증가하였으며, 1,000 ug/mL 농도에서는 동결건조 열수추출물에서 유의적으로 가장 높게 나타났으나, 대조군인 비타민 C에 비해 유의적으로 낮았다(p<0.05). 신경세포 보호효과는 열품 및 동결건조 열수추출물에서 농도의존적으로 높게 나타났으며, 대조군인 비타민 C에 비해 낮았다(p<0.05). 본 연구를 통하여 열풍건조에 비해 동결건조 초석잠의 열수추출물이 총 flavonoid와 총 polyphenol 함량이 더 높게 함유되어 있어 항산화 활성 및 산화적 스트레스로부터의 신경세포 보호효과가 우수하게 나타내는 것이 관찰되었다.

This study was carried out to identify medicinal mushrooms with protective effects against oxidative stress in PC12 neuronal cell line, followed by evaluation of their antioxidant property. Extracts of medicinal mushrooms, including Ganoderma lucidum extract (GLE), antler-shaped Ganoderma lingzhi extract (AGLE), Hericium erinaceus extract (HEE), and Sanghuangporus baumii extract (SBE), were screened for cytotoxicity using MTT assay. None of the extracts up to 10 μg/ml concentration affected cell viability. These extracts were further checked for their protective effect against oxidative stress-induced reactive oxygen species (ROS) production. Exposure to 50 μM H₂O₂ induced ROS generation in PC12 cells, which was inhibited only by treatment with AGLE. In addition, inhibition of H₂O₂-induced ROS generation by AGLE was found to be in a dose-dependent manner (2.5, 5, and 10 μg/ml). Microscopic examination of DCF fluorescence for detection of ROS showed a similar pattern. Further, antioxidant activity of AGLE was determined by ABTS radical cation assay, and its IC50 was found to be 46.90±0.31 μg/ml. Taken together, these results suggest that AGLE may help to alleviate oxidative stress in PC12 neuronal cells.

Actinidia arguta (Actinidiaceae), which is commonly referred to as hardy kiwifruit, has been reported to possess anti-inflammatory, anti-allergic and antioxidative properties. The protective effect of the leaves and stems of A. arguta against amyloid β protein (Aβ) (25-35)-induced cultured neuronal cell death and memory impairment was investigated in the current study. Exposure of cultured cortical neurons to 10 μM Aβ (25-35) for 24 h induced significant neuronal death as assessed by a 3-[4,5-dimethylthiazol- 2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. However, A. arguta (10 and 50 μg/ ml) prevented Aβ (25-35)-induced apoptotic neuronal death in cultured cortical neurons. A. arguta also inhibited the 100 μM H2O2-induced decrease of the MTT reduction rate in cultured neurons. Memory impairment was produced by intracerebroventricular microinjection of 15 nmol Aβ (25- 35) and examined using the passive avoidance test in ICR mice. Chronic treatments with A. arguta (50 and 100 mg/ kg, 14 days, p.o.) significantly prevented memory impairment induced by Aβ (25-35), and A. arguta inhibited the Aβ (25-35)-induced increase of cholinesterase activity in the brains of memory impaired mice. These results suggest that A. arguta might be able to inhibit Aβ (25-35)-induced neuronal death and memory impairment via antioxidative and anti-cholinesterase effects and that A. arguta could have a therapeutic role for preventing the progression of neurodegeneration in Alzheimer’s disease.

This study examined the antioxidant and neuronal cell protective effects of the water and methanol extracts of Eugenia caryophyllata Thunb. The total polyphenol content was significantly higher in the methanol extract than in the water extract. The DPPH radical scavenging activity in the water extract was similar to Vit. C at a concentration of 100~200 μg/mL. The ABTS radical scavenging activity in the water and methanol extract was similar to Vit. C at a concentration of 800~1,000 μg/mL. The superoxide dismutase (SOD)-like activity in the methanol extract was similar to Vit. C at a concentration of 800~1,000 μg/mL. The DPPH, ABTS radical scavenging and (SOD)-like activity increased with increasing extract concentration. In a cell viability using MTT, the water extract (50 and 100 ppm) and methanol extract (100 ppm) had a protective effect against H2O2-induced neurotoxicity.The result ssuggest that the extract of E. caryophyllata Thunb. has antioxidant activities and may be useful for treating neurodegenerative disorders.

Antioxidant and neuronal cell protective effects of aqueous extract from lotus (Nelumbo nucifera) leaf tea (LLTE) were investigated. The 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging effect, ferric reducing antioxidant power, and malondialdehyde inhibition of LLTE were increased in a dose dependent manner. Intracellular reactive oxygen species accumulation resulting from hydrogen peroxide (H2O2) treatment was significantly reduced when LLTE were present in the media compared to PC12 cells treated with H2O2 only. In neuronal cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl- tetrazoliumbromide (MTT), LLTE showed protective effect against H2O2-induced neurotoxicity. In addition, lactate dehydrogenase release into medium was also inhibited by LLTE (7.13-43.89%). Total phenolics of LLTE were 33.16 mg/g and a quercetin was identified as major phenolics (105.93 mg/100g). Therefore, above these data suggest that LLTE including quercetin may be useful in the natural antioxidant substance, and may reduce the risk of neurodegenerative disease.

The generation of patient-specific pluripotent stem cells has the potential to accelerate the implementation of stem cells for clinical treatment of degenerative diseases. This study was to examine the in vitro neuron cell differentiation characteristics of our established human (h) iPS cells (IMR90-iPS-1~2) derived from human somatic cells. For the neuron differentiation, well grown hiPS colonies were recovered by collagenase treatment and then suspended cultured in a non-adherent bacteriological culture dish using human embryonic stem (hES) cell culture medium for 4 days. Embryoid bodies were plated and cultured in serum-free ITSFN (insulin/transferrin/selenium/fibronectin) medium for 8 days to select neural precursor cells. Then selected neuronal cells were dissociated, plated onto poly-L-ornithin/laminin coated dish at a concentration of 2 x 105 cells/cm2 and expanded in N2 medium containing 20 ng/ml bFGF, 200 ng/ml SHH and 100 ng/ml FGF-8 for 7 days. For the final differentiation step involved removing agents and culturing for 14 days in 20 ng/ml BDNF added N2 medium. In the neural precursor stage, >90% of nestin positive cells and >50% NCAM positive cells were obtained. Also, in final differentiation step, we confirmed the high percent (>80%) of mature neuron tubulin-β positive cells and approximately >20% of tyrosine hydroxylase positive cells. Also, these results were confirmed by RT-PCR. These results indicated that hiPS cells have potential to generate specific neuron differentiation and especially TH+ neuron was also can be obtained, and thus hiPS-derived neural cells might be an usable source for the study of neuro-degenerative disease.

자색고구마 추출물의 항산화 효과와 산화적 스트레스로 유도된 PC12 신경세포에 대한 보호효과에 대하여 연구하 였다. 자색고구마 추출물의 총 페놀함량은 44.25 mg/g, monomeric anthocyanin 함량은 2,394 mg/L로 나타났 다. 자색고구마 추출물의 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylben-zthiazoline- 6-sulfonic acid) (ABTS) radical 소거활성, ferric reducing/antioxidant power (FRAP) 및 환원력은 농도 의존 적으로 항산화 활성이 증가하였다. MTT {3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazoliumbromide} reduction assay를 이용하여 자색고구마 추출물의 신경세포 보호효과를 측정한 결과, 세포 생존율이 두드러지게 증가하는 것으로 나타났다. 산화적 스트레스는 신경세포막 손상 정도를 증가시키기 때문에 lactate dehydrogenase (LDH) release assay와 neutral red uptake assay를 이용하여 세포막 손상 보호효과를 조사한 결과 자색고구마 추출물 처리구는 대조구에 비하여 산화적 스트레스로 유도된 세포막 손상 보호효과가 농도 의존적으로 나타났다. 따라서 자색고구마 추출물은 천연 항산화 소재 및 알츠하이머성 치매와 같은 신경퇴행성 질환의 예방 소재로서의 활용 가능성이 기대된다.

The peel of Citrus sunki exhibits multiple biological activities such as anti-oxidant, anti-inflammation and anti-obesity, but little is known about neurodegeneration-related activities. In this study, we investigated the protective effect of ethanolic extract from both immature and mature Citrus sunki peel on neuronal cell death. Treatment of the neuroblastoma cell line SH-SY5Y with MPP+, an inducer of Parkinson disease model, increased cell death in a dose dependent manner. Increased levels of active caspase-3 and cleaved PARP were detected. Treatment with immature Citrus sunki peel extract significantly reduced MPP+-induced neurotoxicity. Cytoprotection with immature Citrus sunki peel extract was associated with a decrease in caspase-3 activation and PARP cleavage. In contrast, mature Citrus sunki peel extract had no significant effects. These data suggest that immature Citrus sunki peel extract may exert anti-apoptotic effect through the inhibition of caspase-3 signaling pathway on MPP+-induced neuronal cell death.

본 연구에서는 20종 생약 열수추출물의 AChE 활성, 산화 스트레스로 인한 지질 과산화물 생성 억제능 및 뇌신경 세포 사멸에 대한 보호효과를 비교하였다. AChE의 억제활 성은 산수유, 감초, 당귀 열수추출물에서 우수하였으며, 그 중 산수유가 가장 높은 억제율을 나타내었다. 또한 H2O2/ FeSO4로 산화 스트레스를 유발시켜 생약 열수추출물의 지 질과산화물 생성 억제 활성을 조사한 결과 소엽, 하수오, 계피 및 감초 열수추출물에서 높은 항산화 활성을 보였다. L-Glutamate에 의해 유도된 신경세포 독성에 대한 보호효 과는 감초, 계피, 길경, 박하 열수추출물의 100 μg/mL 농도 에서 관찰되었다. 본 연구를 종합적으로 살펴보았을 때, 감초 열수추출물이 치매 예방 및 개선제로써의 활용가능성 이 가장 뛰어난 것으로 판단된다. 향후 치매예방 효능을 가지는 새로운 화합물 발굴을 위한 기초자료로 활용될 것으 로 사료된다.

Neural precursor cells (NPCs) with abilities to self-renew and differentiate into neurons are born in the subventricular zone of the hippocampus and the subgranular zone in the adult mammalian brain. NPCs maintain their population by symmetric cell division and neuronal cell differentiation started by asymmetric cell division. Asymmetric cell division produces two daughter cells with different cellular fates. It has been shown that multiple transcription factors, like homeodomain transcription factors and basic helix loop helix (bHLH) transcription factors, play cruel role in cell fate determination (Bertrand et al., 2002). Multipotent cortical progenitors are maintained in a proliferative state by bHLH factors including Id and Hes families. The transition from proliferation to neurogenesis involves a coordinate increase in the activity of proneural bHLH factors (Mash1, Neurogenin1, and Neurogenin2). As development proceeds, inhibition of proneural bHLH factors in cortical progenitors promotes the formation of astrocytes. Finally, the formation of oligodendrocytes is triggered by an increase in the activity of bHLH factors Olig1 and Olig2 that may be coupled with a decrease in Id activity. Thus, bHLH factors have key roles in corticogenesis, affecting the timing of differentiation and the specification of cell fate. Hes1 is a vertebrate homologue of the Drosophila bHLH protein Hairy, originally known as a transcriptional repressor that negatively regulates neuronal differentiation. Hes1 expression in neuronal precursors precedes and represses the expression of the neuronal commitment gene Mash1, a bHLH activator homologus to the proneuronal Achaete-Scute genes in Drosophila (Campuzano and Modolell, 1992). Down regulation of Hes1 expression in developing neuroblasts may be necessary for the induction of a regulatory cascade of bHLH activator proteins that controls the commitment and progression of neural differentiation. Expression of Hes1 inhibited neurite outgrowth, whereas Mash1 expression increased neurite outgrowth. Mash1 can induce bipolar neuron differentiation (Tomita et al., 1996) and NSCs culture obtained from Mash1-/- mice cannot differentiate into GBAergic neurons (Oishi et al., 2009) Hes1 is an essential effector for Notch signaling, which regulates the maintenance of undifferentiated cells (Artavanis-Tsakonas et al., 1999). In contrast, it is previously reported that platelet-derived growth factor induces the expression of Mash1 mRNA by regulating the phosphorylation of Hes1 and TLE1 (Ju et al., 2004). Hes1 is required for neuronal differentiation in PDGF treated NSC cultures. The major cell types in the cerebral cortex and hippocampus are the glutamatergic neurons and the GABAergic neurons. Cholinergic neurons are important in spatial learning and memory formation and depleted in patient’s brain of early Alzheimer’s disease. It has not been clear, however, whether new born adult NPCs could generate different cell types of neurons with distinct cellular and physiological properties. During the development, glutamatergic neurons consisting of radially migrating neurons are originated from the ventricular zone of the dorsal telenchephalon (pallium) and give rise to pyramidal neurons. Glutamate and glutamate receptors are involved in cognitive functions by forming major excitatory network. GABAergic neurons in the neocortex and hippocampus are in part migrated from the ventral telenchephalon or from the dorsal NPCs and function as local interneurons by forming inhibitory networks which regulate large populations of glutamatergic pyramidal neurons. During the development, spatiotemporal gene expression regulated by extracellular signaling factors is believed to determine the formation of neuronal phenotypes. Platelet derived growth factor B is known to induce the differentiation into neurons rather than glial cells in the rat NPCs. We found that platelet derived growth factor B is expressed in dorsal cortex and hippocampus more than in ventral cortex in the period of pyramidal cell differentiation of the embryonic rat brain. It indeed induces cell type specific differentiation into glutamatergic cells that produce the glutamate transpoter, vGluT1 and glutamate at the late stage of differentiation although it promotes neuronal differentiation at the early stage in NPCs primarily cultured from the rat embryonic hippocampus. Brain-derived neurotrophic factor, however, facilitated GABAergic differentiation in the hippocampal NPCs that generate glutamatergic pyramidal cells in a similar manner. We also found many transcriptional factors such as homeobox genes (Dlx1, Nkx2.1, Pax6) and bHLH genes (NeuroD, Ngn1, Hes1) are involved in cell type specific differentiation into glutamatergic, GABAergic, and cholinergic cells. We observed the expression of Pax6, homeodomain transcription factor, and Hes1, bHLH transcription factor, increased during PDGF-induced early differentiation in neural stem cells. These transcription factors, however, are also expressed in differentiated neurons with specific phenotype at late differentiation stage. We found pax6 is expressed in cholinergic neurons in the adult brains and in cultures. Phosphorylation of neurogenic transcription factors by protein kinases has been reported as predominant strategy in gene regulation during neuronal development and these regulated activities of different transcription factors are known to be involved in cell fate determination. Homeodomaininteracting protein kinases2 (HIPK2) which belongs to HIPK family has been identified as a nuclear serine-threonine kinase and is known to interact with several transcription factors to regulate gene transcriptions. Among several transcription factors, HIPK2 is mainly reported to target the homeodomain transcription factors such as Nkx and Pax6. Considering the importance of homeodomain transcription factors in neurogenesis and differentiation, HIPK2 also seem to play critical roles in those transcriptional regulations during embryogenesis. To define the roles of HIPK2 in neuronal differentiation during embryonic development, we investigated the expression patterns of neurogenic transcription factors such as Pax6, Hes1 and Mash1 in HIPK2 overexpressing NSCs. Hes1 showed different expression patterns between the wild type and mutant HIPK2 overexpressed cells and Mash1, which is reported to be repressed by Hes1, also showed altered expression patterns. We detected the mRNA expression of Hes1 is upregulated by HIPK2 during neuronal differentiation. The overexpressed Pax6 induced differentiation of neural stem cells into cholinergic neurons and suppressed differentiation into GABAnergic neuron both in vitro and in vivo transplantation study. To evaluate the effect of Pax6 on the transcriptional activation of Hes1 promoter, we performed luciferase reporter assay in NIH3T3 cells. Reporter expression of Hes1 promoter was enhanced upon stimulation with wild type Pax6 and wild type HIPK2. Furthermore, the HDAC inhibition mediated by TSA(Trichostatin A) has been shown to repress the reporter expression. The treatment of TSA increased neurofilaments and GAD expression in E14.5 cortical neuronal cell. These findings suggest that Pax6 promotes neuronal subtype differentiation via regulation of Hes1 bHLH transcription factor, which is mediated by HDAC. To examine the effect of Pax6 and HIPK2 on the transcriptional activation of Hes1, efficiency of hes1 promoter was measured by a luciferase reporter assay. When DNA constructs encoding Pax6 and HIPK2 were transfected along with Hes1 promoter, the expression of the reporter was highly increased. Furthermore, the HDAC inhibition mediated by TSA(Trichostatin A) repressed the reporter expression. Interaction of Pax6 and HIPK2 was shown by co-immunoprecipitation and binding of Pax6 to hes1 promoter was detected by chromatin immunoprecipitation. I also found overexpression of HIPK2 and Pax6 facilitated neural stem cells to differentiate into cholinergic cell fate in NSCs primarily cultured from the rat hippocampus. This is also supported by analysis of the brains of sey/neu Pax6 mutant mice and HIPK2 knock out mice. These findings suggest that Pax6 activation by HIPK2 promotes neuronal subtype differentiation via up regulation of Hes1 and down regulation of Mash1 and it is mediated by HDAC.

본 연구에서는 시판 메밀차 열수 추출물의 항산화 효과 및 신경세포 보호효과를 조사하였다. 시판 메밀차 열수 추출물의 ABTS 라디칼 소거 활성, FRAP 및 MDA 생성 저해 실험결과 농도 의존적인 경향이 나타났으며 또한 높은 항산화 활성을 보여주었다. 과산화수소로 유발된 산화적 손상에 의한 ROS 축적량을 조사한 결과 단독 처리구보다 메밀차 열수 추출물 처리구에서 낮은 ROS 축적량을 나타내었다. MTT 및 LDH 분석을 통한 PC12 세포

PC12 신경세포를 이용하여 구아바 열매와 잎 추출물이 로 유도된 신경세포 독성에 대한 보호 효과를 조사하였다. 구아바 열매와 잎 열수 추출물의 총페놀성 화합물 함량은 각각 11.75 및 293.25 mg/g이었고, gallic acid 함량은 각각 22.78 및 117.34 mg/100 g이었다. 처리한 PC12 cell내의 활성산소 생성억제효과를 측정한 결과 구아바 잎열수 추출물에서 높은 활성산소 생성 억제효과를 보였다. MTT방법을 이용하

본 연구에서는 예비실험결과 높은 총 페놀 화합물 함량(17.71 mg/g)을 나타낸 어성초 60% 메탄올 추출물의 항산화 효과 및 신경세포 보호효과를 알아보기 위해 다양한 연구를 진행하였다. 어성초의 DPPH와 ABTS radical 소거 활성 및 FRAP assay결과 농도 의존적인 경향이 나타났으며, 높은 항산화 활성을 보여주었다. MTT, LDH assay를 통한 신경세포 보호효과를 측정한 결과 MTT 실험에서는 어성초 60% 메탄올 추출물

A stroke is the major cause of death and can cause neurological damage. The striatum serves as an input gate of the basal ganglia in assisting motor behavior. The activity-dependent synaptic plasticity in the dorsal striatum (DS) is known to play a key role for recovery of motor control after brain injury. Exercise supports functional recovery from ischemic brain injury through brain-derived neurotrophic factor (BDNF) -induced synaptic plasticity. Exercise upregulate the levels of BDNF within both the hippocampus and cerebral cortes and might act as a gate that primes the brain to respond to environmental stimulation, while simultaneously increasing the ability of neurons to resist insult. However, little is known about the effects of exercise on neuroprotection in the DS. Therefore, in this study we attempted to investigate the effects of exercise on the neuronal cell population in the DS. Transient focal brain ischemia was induced by middle cerebral artery occlusion (MCAO) on male Sprague-Dawley rats (300±30). Animals were subjected to forced treadmill exercise group and sedentary group after MCAO. Exercise improved neurologic functions measured by modified neurological severity score. Exercise group showed reduced infarct volume measured by vital staining with 2,3,5-triphenyltetrazolium chloride. Immunohistochemical analysis was performed in the DS with antibodies of neuronal nuclei (NeuN) protein, glial fibrillary acidic protein (GFAP), a matured neuronal marker and an astrocyte marker respectively and BDNF. Ischemic injury decreased NeuN+ cell population but exercise attenuated this decrease while increase in GFAP+ cell population induced by MCAO was inhibited by exercise. These findings suggest that the neurological function recovery by exercise after ischemic brain injury may be mediated by alteration of neuronal cell population in the DS.

Cerebral ischemia results from a transient or permanent reduction in cerebral blood flow that decreases oxygen and glucose supply. When the cellular oxygen supply is reduced to critical level, damage to cells and induction of cell death are occurred by excitotoxicity, oxidative stress and inflammation. Ischemia remains one of the leading causes of death, but there is no effective treatment that might protect neurons gainst ischemia by interrupting the cascade of cell death. In this study, human neuroblastoma SH-SY5Y cells are exposed to oxygen and glucose deprivation (OGD) followed by reoxgenation. OGD can mimic the acute restriction of metabolite and oxygen supply caused by ischemia and is widely used as a model of ischemic conditions. SH-SY5Y cells are treated samples at the commencement of OGD to achieve different final concentrations, and cell viabilities were quantified using the measurement of flow cytometry analysis. Of those tested, the extracts of Polygala tenuifolia (roots), Dictamnus dasycarpus (barks), Polygala tenuifolia (roots), Eucommia ulmoides (branches), Eucommia ulmoides (barks), Poria cocos (whole), Sophora flavescens (roots) showed neuroprotective effects, with EC50 values of 4.5±0.6, 7.9±1.5, 10.5±0.7, 18.4±1.9, 19.6±0.3, 21.6±1.9, and 30.7±3.9μg/ml, respectively.

This study investigated the protective roles and mechanism of magnolol, from the stem bark of Magnolia officinalis against potential neurotoxin 3-hydroxykynurenine (3-HK)-induced neuronal cell death. For the evaluation of protective role of magnolol, we examined cell viability, apoptotic nuclei, change of mitochondrial membrane potential and caspase activity in human neuroblastoma SH-SY5Y cells. It was found that 3-HK induces neuronal cell death in the human neuroblastoma SH-SY5Y cell line. The reduced cell viability produced characteristic features such as cell shrinkages, plasma membrane blebbing, chromatin condensation, and nuclear fragmentation. The cells treated with 3-HK showed an increase in the concentration of reactive oxygen species (ROS) as well as in caspase activity. In addition, both are involved in the 3-HK-induced apoptosis. Magnolol attenuated the cell viability reduction by 3-HK in both a dose- and time-dependent manner. Optical microscopy showed that magnolol inhibited the cell morphological features in the 3-HK-treated cells. Furthermore, the increase in the ROS concentration and the caspase activities by 3-HK were also attenuated by magnolol. These results showed that magnolol has a protective effect on the 3-HK induced cell death by inhibiting ROS production and caspase activity.