• Nutrition Research and Practice
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• 제14권6호
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• pp.593-605
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• 2020

BACKGROUND/OBJECTIVES: Alzheimer's disease is common age-related neurodegenerative condition characterized by amyloid beta (Aβ) accumulation that leads cognitive impairment. In the present study, we investigated the protective effect of paeoniflorin (PF) against Aβ-induced neuroinflammation and the underlying mechanism in C6 glial cells. MATERIALS/METHODS: C6 glial cells were treated with PF and Aβ_25-35, and cell viability, nitric oxide (NO) production, and pro-inflammatory cytokine release were measured. Furthermore, the mechanism underlying the effect of PF on inflammatory responses and Aβ degradation was determined by Western blot. RESULTS: Aβ_25-35 significantly reduced cell viability, but this reduction was prevented by the pretreatment with PF. In addition, PF significantly inhibited Aβ_25-35-induced NO production in C6 glial cells. The secretion of interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha was also significantly reduced by PF. Further mechanistic studies indicated that PF suppressed the production of these pro-inflammatory cytokines by regulating the nuclear factor-kappa B (NF-κB) pathway. The protein levels of inducible NO synthase and cyclooxygenase-2 were downregulated and phosphorylation of NF-κB was blocked by PF. However, PF elevated the protein expression of inhibitor kappa B-alpha and those of Aβ degrading enzymes, insulin degrading enzyme and neprilysin. CONCLUSIONS: These findings indicate that PF exerts protective effects against Aβ-mediated neuroinflammation by inhibiting NF-κB signaling, and these effects were associated with the enhanced activity of Aβ degradation enzymes.

• The Korean Journal of Physiology and Pharmacology
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• 제23권6호
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• pp.483-491
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• 2019

Cordycepin exerts neuroprotective effects against excitotoxic neuronal death. However, its direct electrophysiological evidence in Alzheimer's disease (AD) remains unclear. This study aimed to explore the electrophysiological mechanisms underlying the protective effect of cordycepin against the excitotoxic neuronal insult in AD using whole-cell patch clamp techniques. ${\beta}$-Amyloid ($A{\beta}$) and ibotenic acid (IBO)-induced injury model in cultured hippocampal neurons was used for the purpose. The results revealed that cordycepin significantly delayed $A{\beta}$ + IBO-induced excessive neuronal membrane depolarization. It increased the onset time/latency, extended the duration, and reduced the slope in both slow and rapid depolarization. Additionally, cordycepin reversed the neuronal hyperactivity in $A{\beta}$ + IBO-induced evoked action potential (AP) firing, including increase in repetitive firing frequency, shortening of evoked AP latency, decrease in the amplitude of fast afterhyperpolarization, and increase in membrane depolarization. Further, the suppressive effect of cordycepin against $A{\beta}$ + IBO-induced excessive neuronal membrane depolarization and neuronal hyperactivity was blocked by DPCPX (8-cyclopentyl-1,3-dipropylxanthine, an adenosine $A_1$ receptor-specific blocker). Collectively, these results revealed the suppressive effect of cordycepin against the $A{\beta}$ + IBO-induced excitotoxic neuronal insult by attenuating excessive neuronal activity and membrane depolarization, and the mechanism through the activation of $A_1R$ is strongly recommended, thus highlighting the therapeutic potential of cordycepin in AD.

• Biomolecules & Therapeutics
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• 제32권1호
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• pp.77-83
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• 2024

Alzheimer's disease (AD) is a neurodegenerative disease characterized by neuronal cell death and memory impairment. Corticosterone (CORT) is a glucocorticoid hormone produced by the hypothalamic-pituitary-adrenal axis in response to a stressful condition. Excessive stress and high CORT levels are known to cause neurotoxicity and aggravate various diseases, whereas mild stress and low CORT levels exert beneficial actions under pathophysiological conditions. However, the effects of mild stress on AD have not been clearly elucidated yet. In this study, the effects of low (3 and 30 nM) CORT concentration on Aβ_25-35-induced neurotoxicity in SH-SY5Y cells and underlying molecular mechanisms have been investigated. Cytotoxicity caused by Aβ_25-35 was significantly inhibited by the low concentration of CORT treatment in the cells. Furthermore, CORT pretreatment significantly reduced Aβ_25-35-mediated pro-apoptotic signals, such as increased Bim/Bcl-2 ratio and caspase-3 cleavage. Moreover, low concentration of CORT treatment inhibited the Aβ_25-35-induced cyclooxygenase-2 and pro-inflammatory cytokine expressions, including tumor necrosis factor-α and interleukin-1β. Aβ_25-35 resulted in intracellular accumulation of reactive oxygen species and lipid peroxidation, which were effectively reduced by the low CORT concentration. As a molecular mechanism, low CORT concentration activated the nuclear factor-erythroid 2-related factor 2, a redox-sensitive transcription factor mediating cellular defense and upregulating the expression of antioxidant enzymes, such as NAD(P)H:quinone oxidoreductase, glutamylcysteine synthetase, and manganese superoxide dismutase. These findings suggest that low CORT concentration exerts protective actions against Aβ_25-35-induced neurotoxicity and might be used to treat and/or prevent AD.

• Journal of Ginseng Research
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• 제48권1호
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• pp.59-67
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• 2024

Background: Alzheimer's disease (AD) has memory impairment associated with aggregation of amyloid plaques and neurofibrillary tangles in the brain. Although anti-amyloid β (Aβ) protein antibody and chemical drugs can be prescribed in the clinic, they show adverse effects or low effectiveness. Therefore, the development of a new drug is necessarily needed. We focused on the cognitive function of Panax ginseng and tried to find active ingredient(s). We isolated panaxcerol D, a kind of glycosyl glyceride, from the non-saponin fraction of P. ginseng extract. Methods: We explored effects of acute or sub-chronic administration of panaxcerol D on cognitive function in scopolamine- or Aβ_25-35 peptide-treated mice measured by several behavioral tests. After behavioral tests, we tried to unveil the underlying mechanism of panaxcerol D on its cognitive function by Western blotting. Results: We found that pananxcerol D reversed short-term, long-term and object recognition memory impairments. The decreased extracellular signal-regulated kinases (ERK) or Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in scopolamine-treated mice was normalized by acute administration of panaxcerol D. Glial fibrillary acidic protein (GFAP), caspase 3, NF-kB p65, synaptophysin and brainderived neurotrophic factor (BDNF) expression levels in Aβ_25-35 peptide-treated mice were modulated by sub-chronic administration of panaxcerol D. Conclusion: Pananxcerol D could improve memory impairments caused by cholinergic blockade or Aβ accumulation through increased phosphorylation level of ERK or its anti-inflammatory effect. Thus, panaxcerol D as one of non-saponin compounds could be used as an active ingredient of P. ginseng for improving cognitive function.

• 한국응용과학기술학회지
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• 제37권3호
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• pp.418-428
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• 2020

본 연구는 알츠하이머(Alzheimer's disease: AD) 형질전환 생쥐를 대상으로 저항성 운동(resistance exercise: RE)이 해마의 베타 아밀로이드(β-amyloid: Aβ) 단백질 대사, 신경세포사멸 및 인지기능에 미치는 영향을 확인하는데 목적이 있다. AD 비 형질전환 생쥐(non-transgenic: non-tg, n=14)와 형질전환 생쥐(transgenic: Tg, n=14)를 무선 배정하여 비 형질전환 생쥐 대조군 (non-tg-control: NTC, n=7), 비 형질전환 생쥐 저항성 운동군(non-tg-RE: NTRE, n=7), 형질전환 대조군(tg-control: TC, n=7) 및 형질전환 저항성 운동군(tg-RE: TRE, n=7)으로 구분하였다. RE는 특수 제작한 사다리 저항성 운동 기구를 사용하여 점진적으로 set 수를 증가시켜 총 8주간 실시하였다. 운동 후 인지기능 능력을 평가하기 위한 수중미로검사와 Aβ 단백질 대사, 신경세포사멸 지표 및 SIRT1/PGC-1α 단백질 발현 수준을 확인하였다. 수중미로검사 결과 거리와 시간 모두 TC 집단에서 유의하게 증가 되었지만 RE를 실시한 TRE 집단에서 거리와 시간이 감소 되어 인지능력이 개선된 것으로 확인되었다. 또한, TC 집단에서 증가된 Aβ 단백질 발현은 RE를 통해 감소하는 것으로 나타났다. 신경세포사멸 관련 단백질인 Bcl-2/Bax ratio는 TC 집단에서 유의하게 감소되어 신경세포사멸이 증가 된 것으로 나타났지만 RE는 Bcl-2/Bax ratio을 증가시켜 신경세포사멸을 감소시킨 것으로 확인되었다. TC 집단에서 증가된 BACE1 및 ROCK1과 감소된 ADAM10과 RARβ 단백질 발현은 RE를 통해 감소되거나 증가 된 것으로 나타났고, SIRT1/PGC-1α 단백질 발현은 TC 집단에서 감소 되었지만 RE를 통해 증가 된 것으로 나타났다. 따라서 8주간의 RE는 AD의 병리학적 특징인 Aβ 단백질 발현을 감소시키고 관련 생성 기전들을 조절하여(SIRT1/PGC-1α 기전 활성, 아밀로이드 생성기전 억제, 비-아밀로이드 생성기전 활성) 신경세포사멸 억제시키고 결과적으로 인지기능을 개선 시킬 수 있는 효과적인 운동 방법이라고 생각된다.

• 한국식품영양과학회지
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• 제45권11호
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• pp.1552-1563
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• 2016

본 연구는 양파의 불쾌치를 저감화시킨 무취음료와 양파 과피 추출물을 첨가한 생리활성 성분 강화음료의 $H_2O_2$로 유도된 산화적 스트레스에 대한 뇌신경세포 보호 효과와 $A{\beta}$로 유도된 인지기능 장애 동물모델에서의 개선 효과를 검증하고자 수행되었다. 뇌신경세포 보호 효과에서는 상대적으로 강화음료에서 무취음료 대비 우수한 산화적 스트레스 억제효과 및 생존율을 나타내었다. $A{\beta}$로 유도된 인지기능 장애 동물모델에 있어 Y-maze, passive avoidance 및 Morris water maze test에서 강화음료가 상대적으로 우수한 학습 및 기억력 개선 효과를 나타내는 것을 확인할 수 있었다. 마우스의 뇌 조직에서 강화음료 그룹은 AChE 활성을 저해하고, 신경전달물질인 ACh의 함량을 증가시킴으로써 $A{\beta}$로 유도된 cholinergic system 장애에 있어 개선 효과를 나타내었다. 또한, 마우스 뇌에서 SOD 함량의 증가, oxidized GSH/total GSH와 MDA 함량을 감소시킴으로써 $A{\beta}$와 같은 산화적 스트레스 인자에 대한 뛰어난 항산화 효과를 나타내었다. 최종적으로 무취음료와 강화음료의 주요성분들을 Q-TOF UPLC/MS system을 통하여 분석한 결과, 강화음료의 경우 무취음료보다 생리활성을 가진 2개의 steroidal saponin과 6개의 phenolic 화합물 등이 추가 검출되었다. 이러한 결과들을 종합해볼 때 강화음료는 상대적으로 protocatechuic acid와 quercetin 같은 강력한 항산화 효과를 나타내는 phenolic 화합물과 steroidal saponin 계열에 의한 우수한 인지기능 개선 효과를 기반으로 한 고부가가치 식품으로 활용될 수 있는 산업적 가능성이 있다고 판단된다.

• 대한영상의학회지
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• 제84권3호
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• pp.638-652
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• 2023

목적 경도인지장애와 알츠하이머 치매 환자에서 아밀로이드베타 양성을 예측할 수 있는 MRI 특징을 알아보고 머신러닝으로 아밀로이드베타 양성 예측 모형의 성능을 알아보고자 하였다. 대상과 방법 후향적 및 단면조사연구로 경도인지장애와 알츠하이머 치매 총 139명의 환자를 대상으로 하였다. 이들은 모두 뇌 MRI와 아밀로이드 PET-CT를 시행하였다. 대상자는 아밀로이드 베타 양성군(n = 84)과 아밀로이드 베타 음성군(n = 55)으로 분류하였다. 시각적 분석으로는 뇌백질 고신호 병변의 Fazekas 척도와 뇌미세출혈 개수를 시행하였다. 정량분석으로 뇌백질 고신호 병변의 부피와 국소뇌부피를 측정하였다. 다중 로지스틱 회귀분석과 머신러닝 기법으로 아밀로이드베타 양성을 가장 잘 예측할 수 있는 MRI 특징을 확인하였다. 결과 시각적분석에서 아밀로이드베타 양성군은 뇌백질 고신호 병변의 Fazekas 척도(p = 0.02)와 뇌미세출혈 개수(p = 0.04)가 유의미하게 높았다. 해마, 내후각피질, 설전부의 국소뇌부피들은 아밀로이드베타 양성군에서 유의미하게 작았다(p < 0.05). 제3뇌실(p = 0.002)의 부피는 아밀로이드베타 양성군에서 유의미하게 컸다. 간이 정신 상태 검사와 국소뇌부피를 이용하여 머신러닝기법을 이용했을 때 좋은 정확도를 보였다(81.1%). 결론 간이 정신 상태 검사, 제3뇌실과 해마 부피를 이용한 머신러닝의 적용은 아밀로이드베타 양성을 예측하는데 활용될 수 있다.

• 생명과학회지
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• 제30권7호
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• pp.598-605
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• 2020

아롱부챗말은 갈조강에 속하는 갈조류의 일종이다. 이전의 보고에 의하면 아롱부챗말은 amyloid-β에 의한 신경병증을 완화하고 혈소판 응집도 억제하는 것으로 알려져 있다. 본 연구는 아롱부챗말의 피부미백 효과를 평가하고 활성 성분을 확인하도록 고안되었다. 이러한 연구를 위하여 아롱부챗말 99% 에틸알코올을 이용하여 추출하였고 활성은 arbutin을 양성 대조군으로 하여 비교하였다. 먼저, 아롱부챗말 추출물은 멜라닌 생성의 속도조절효소인 tyrosinase의 활성을 용량 의존적으로 억제함을 확인하였다. 주목할만한 점으로, 200 μM arbutin은 tyrosinase의 활성을 58.1% 억제한 반면, 0.5% 아롱부챗말 추출물은 76.7% 억제하였다. 아롱부챗말 추출물은 α-melanocyte-stimulating hormone에 의한 TRP-1과 TRP-2 mRNA 발현 증가도 저해하였다. 게다가, 아롱부챗말 추출물은 흑색종 세포인 B16F10 세포에서 멜라닌의 합성을 유의하게 감소시켰다. 아롱부챗말의 활성성분으로는 fucosterol이 확인되었고 함량분석에서 0.66%로 확인되었다. Fucosterol은 흑생종 세포에서 멜라닌 합성 억제 효과가 고시 성분인 arbutin과 유사하였다. 마지막으로, 아롱부챗말의 세포독성을 MTT assay와 LDH release assay를 이용하여 분석하였다. 이 실험에서 아롱부챗말 추출물은 LDH 유출을 유의하게 감소시키는 것을 확인하였다. 종합하면, 본 연구에서는 아롱부챗말 추출물이 피부 미백용 화장품의 활성성분으로 사용되기에 충분한 가능성을 갖고 있는 것으로 확인하였다.

• Journal of Korean Neurosurgical Society
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• 제29권4호
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• pp.461-470
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• 2000

Objective : Many investigators have demonstrated the protective effects of hypothermia following traumatic brain injury(TBI) in both animals and humans. It has long been recognized that mild to moderate hypothermia improves neurologic outcomes as well as reduces histologic and biochemical sequelae after TBI. In this study, two immunohistochemical staining using terminal deoxynucleotidyl-transferase-mediated biotin dUTP nick end labeling(TUNEL), staining of apoptosis, and ${\beta}$-amyloid precursor protein(${\beta}$-APP), a marker of axonal injury, were done and the authors evaluated the protective effects of hypothermia on axonal and neuronal injury after TBI in rats. Material and Method : The animals were prepared for the delivery of impact-acceleration brain injury as described by Marmarou and colleagues. TBI is achieved by allowing of a weight drop of 450gm, 1 m height to fall onto a metallic disc fixed on the intact skull of the rats. Fourty Sprague-Dawley rats weighing 400 to 450g were subjected to experimental TBI induced by an impact-acceleration device. Twenty rats were subjected to hypothermia after injury, with their rectal temperatures maintained at $32^{\circ}C$ for 1 hour. After this 1-hour period of hypothermia, rewarming to normothermic levels was accomplished over 30-minute period. Following 12 hours, 24 hours, 1 week and 2 weeks later the animals were killed and semiserial sagittal sections of the brain were reacted for visualization of the apoptosis and ${\beta}$-APP. Results : The density of ${\beta}$-APP marked damaged axons within the corticospinal tract at the pontomedullary junction and apoptotic cells at the contused cerebral cortex were calculated for each animal. In comparison with the untreated controls, a significant reduction in ${\beta}$-APP marked damaged axonal density and apoptotic cells were found in all hypothermic animals(p<0.05). Conclusion : This study shows that the posttraumatic hypothermia result in substantial protection in TBI, at least in terms of the injured axons and neurons.

• 대한본초학회지
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• 제30권1호
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• pp.67-75
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• 2015

Objectives : The aim of this study is to examine the neuroprotective effect of wheat bran extract (WBE) against ${\beta}$-amyloid ($A{\beta}$)-induced apoptotic cell death in SH-SY5Y human neuroblastoma cells and memory impairment in triple transgenic animal model's of Alzheimer's disease (3xTg AD mice). Methods : In SH-SY5Y cells, MTT assay and TUNEL staining were conducted to evaluate the protective effect of WBE against $A{\beta}_{25-35}$-induced neurotoxicity and apoptosis. Alterations in mitochondrial transmembrane potential (MMP), expression of proapoptotic Bax and antiapoptotic Bcl-2 proteins, cleavage of PARP, and brain-derived neurotrophic factor (BDNF) levels were analyzed to elucidate the neuroprotective mechanism of WBE. To further investigate the memory enhancing effect of WBE, Morris water maze test was performed in 3xTg AD mice. Results : In SH-SY5Y cells, WBE protected against $A{\beta}_{25-35}$-caused cytotoxicity and apoptosis as shown by the restoration of cell viability in MTT assay and inhibition of DNA fragmentation in TUNEL staining. $A{\beta}_{25-35}$-induced apoptotic signals such as dissipation of MMP, decreased Bcl-2/Bax ratio, and cleavage of PARP were suppressed by WBE. Moreover, WBE up-regulated the protein levels of BDNF, which seemed to be mediated by activation of cAMP response element-binding protein (CREB). In 3xTg AD mice, oral administration of WBE attenuated learning and memory deficit as verified by reduced mean escape latency in water maze test. Conclusions : WBE protects neuronal cells from $A{\beta}_{25-35}$-induced apoptotic cell death and restores learning and memory impairments in 3xTg AD mice. These findings suggest that WBE exhibit neuroprotective potential for the management of AD.