In vitro protective effects of Withania somnifera (L.) dunal root extract against hydrogen peroxide and β‐amyloid(1–42)‐induced cytotoxicity in differentiated PC12 cells

Withania somnifera L. Dunal (Solanaceae), also known as ‘ashwagandha’ in Sanskrit and as ‘Indian ginseng’, is used widely in Ayurvedic medicine as a nerve tonic and memory enhancer, with antiaging, antistress, immunomodulatory and antioxidant properties. There is a paucity of data on the potential neuroprotective effects of W. somnifera root, as traditionally used, against H₂O₂‐ and Aβ_(1–42)‐induced cytotoxicity which are current targets for novel approaches to treat dementia, especially dementia of the Alzheimer's type (AD). In this study, an aqueous extract prepared from the dried roots of W. somnifera was assessed for potential protective effects against H₂O₂‐ and Aβ_(1–42)‐aggregated fibril cytotoxicity by an MTT assay using a differentiated rat pheochromocytoma PC12 cell line. The results suggest that pretreatments of differentiated PC12 cells with aqueous extracts of W. somnifera root significantly protect differentiated PC12 cells against both H₂O₂‐ and Aβ_(1–42)‐induced cytotoxicity, in a concentration dependent manner. To investigate the compounds that could explain the observed effects, the W. somnifera extract was analysed by liquid chromatography–serial mass spectrometry and numerous withanolide derivatives, including withaferin A, were detected. These results demonstrate the neuroprotective properties of an aqueous extract of W. somnifera root and may provide some explanation for the putative ethnopharmacological uses of W. somnifera for cognitive and other neurodegenerative disorders that are associated with oxidative stress. Copyright © 2010 John Wiley & Sons, Ltd.     

清开灵注射液对血脑屏障模型通透性的影响

目的通过观察清开灵注射液对血脑屏障（BBB）模型通透性的影响,探究其抗脑缺血再灌注损伤作用的可能机制及靶点。方法采用细胞插入器培养单层脑微血管内皮细胞,建立体外BBB模型,三气培养箱中1%O2模拟缺氧培养24 h,分为正常组、缺氧组、清开灵小剂量组和大剂量组,通过对跨内皮细胞电阻（TEER）和辣根过氧化物酶（HRP）透过率的测定,观察清开灵注射液对缺氧损伤BBB通透性的影响。结果清开灵注射液可改善缺氧对BBB造成的损伤,提高TEER,降低跨内皮细胞通透性,并且有剂量依赖的趋势,清开灵注射液大剂量组与缺氧组比较,差异有统计学意义（P〈0.01）,清开灵注射液小剂量组改善作用虽不如大剂量组显著,但亦能减少HRP透过BBB（P〈0.05）。结论清开灵注射液能有效改善缺氧损伤造成的BBB功能受损。     

Neurotherapeutic Effects of Pueraria mirifica Extract in Early‐ and Late‐Stage Cognitive Impaired Rats

We determined the neurotherapeutic effects of Pueraria mirifica extract (PME) and pure puerarin (PU) in comparison with 17β‐estradiol (E₂) in early‐ and late‐stage cognitive impaired rats. Rats were ovariectomized (OVX), kept for 2 and 4 months to induce early‐ and late‐stage cognitive impairment, respectively, and divided into four groups that were treated daily with (i) distilled water, (ii) 100 mg/kg of PME, (iii) 7 mg/kg of PU, and (iv) 80 µg/kg of E₂ for 4 months. The estrogen deficiency symptoms of OVX rats were abrogated by treatment with E₂ or PME, but not by treatment with PU. The mRNA level of genes associated with amyloid production (App and Bace1) and hyperphosphorylated Tau (Tau4) were upregulated together with the level of impaired cognition in the 2‐ and 4‐month OVX rats. Treatment with E₂ reduced the level of cognitive impairment more than that with PME and PU, and 2‐month OVX rats were more responsive than 4‐month OVX rats. All treatments down‐regulated the Bace1 mRNA level in 2‐month OVX rats, while PU and PME also decreased the App mRNA level in 2‐ and 4‐month OVX rats, respectively. Only PU suppressed Tau4 expression in 2‐month OVX rats. Thus, PME and PU elicit neurotherapeutic effects in different pathways, and earlier treatment is optimal. Copyright © 2016 John Wiley & Sons, Ltd.     

麝香配伍冰片对大鼠局灶性脑缺血再灌注损伤的脑保护研究

目的:研究麝香配伍冰片对局灶性脑缺血再灌注损伤大鼠的脑保护作用。方法:用颈内动脉线栓法建立大鼠局灶性脑缺血再灌注模型,检测脑梗死体积,并比较其神经功能行为积分;干湿重法观察脑含水量的变化,通过收集透出脑血管外的伊文思蓝(EB)来示踪血脑屏障(BBB)的变化。结果:脑缺血2h再灌注24h,与假手术组比较模型组脑梗死体积显著增大(P<0.01),神经功能行为积分显著升高(P<0.01);麝香冰片组脑梗死体积较模型组缩小(P<0.05),同时,麝香冰片组、麝香组可使大鼠神经功能行为积分下降(P<0.05～0.01),其中以麝香冰片组作用最明显;模型组较假手术组脑含水量及EB含量明显增加(P<0.01),血脑屏障遭到破坏;麝香冰片组脑含水量较模型组明显降低(P<0.05),麝香冰片组及冰片组EB含量较模型组明显降低(P<0.01)。结论:麝香配伍冰片可减少局灶性脑缺血再灌注大鼠脑梗死体积、改善脑缺血后神经行为症状,有效降低脑缺血再灌注后脑含水量及血脑屏障的通透性,对局灶性脑缺血再灌注损伤大鼠有一定的脑保护作用。     

Effects of the Total Alkaloidal Extract of Murraya koenigii Leaf on Oxidative Stress and Cholinergic Transmission in Aged Mice

Alzheimer's disease (AD) is characterized by signs of major oxidative stress and the loss of cholinergic cells. The present study was designed to investigate the role of the total alkaloidal extract from Murraya koenigii (MKA) leaves on age related oxidative stress and the cholinergic pathway in aged mice. Ascorbic acid (100 mg/kg, p.o.) was used as a standard drug. The MKA improved the level of protective antioxidants such as glutathione peroxidase (GPx), reduced glutathione (GSH), glutathione reductase (GRD), superoxide dismutase (SOD) and catalase (CAT) in brain homogenate at higher doses (20 and 40 mg/kg, p.o.). Moreover, a dose dependent decline was noted in lipid peroxidation (LPO) and the nitric oxide assay (NO) at all doses of MKA (10, 20 and 40 mg/kg, p.o.). Interestingly, significant progress was noted with the supplementation of MKA by an improvement of the acetylcholine (ACh) levels and a reduction in the acetylcholinesterase (AChE) activity in aged mouse brain. In addition, a significant elevation of serum albumin (ALBU), alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST) and total protein as well as a decline in creatinine, total cholesterol, urea nitrogen and glucose levels with MKA also ameliorated the hepatic and renal functions in normal ageing process. The results showed the possible utility of Murraya koenigii leaves in neuroprotection against neurodegenerative disorders such as Alzheimer's disease. Copyright © 2012 John Wiley & Sons, Ltd.     

Acute and Sub‐Acute Oral Toxicity Assessment of the Hydroalcoholic Extract of Withania somnifera Roots in Wistar Rats

Withania somnifera is a widely used medicinal plant for several disorders. Toxicity studies on Withania somnifera are not available. Acute and sub‐acute oral toxicities of Withania somnifera root extract in Wistar rats were evaluated in the present study. In the acute toxicity study, WSR extract was administered to five rats at 2000 mg/kg, once orally and were observed for 14 days. No toxic signs/mortality were observed. In the sub‐acute study, WSR extract was administered once daily for 28 days to rats at 500, 1000 and 2000 mg/kg, orally. No toxic signs/mortality were observed. There were no significant changes (P < 0.05) in the body weights, organ weights and haemato‐biochemical parameters in any of the dose levels. No treatment related gross/histopathological lesions were observed. The present investigation demonstrated that the no observed adverse effect level was 2000 mg/kg body weight per day of hydroalcoholic extract of W. somnifera in rats and hence may be considered as non‐toxic. Copyright © 2012 John Wiley & Sons, Ltd.     

Influence of the Green Tea Leaf Extract on Neurotoxicity of Aluminium Chloride in Rats

Aluminium may have an important role in the aetiology/pathogenesis/precipitation of Alzheimer's disease. Because green tea (Camellia sinensis L.) reportedly has health‐promoting effects in the central nervous system, we evaluated the effects of green tea leaf extract (GTLE) on aluminium chloride (AlCl₃) neurotoxicity in rats. All solutions were injected into the cornu ammonis region 1 hippocampal region. We measured the performance of active avoidance (AA) tasks, various enzyme activities and total glutathione content (TGC) in the forebrain cortex (FbC), striatum, basal forebrain (BFb), hippocampus, brain stem and cerebellum. AlCl₃ markedly reduced AA performance and activities of cytochrome c oxidase (COX) and acetylcholinesterase (AChE) in all regions. It decreased TGC in the FbC, striatum, BFb, hippocampus, brain stem and cerebellum, and increased superoxide dismutase activity in the FbC, cerebellum and BFb. GTLE pretreatment completely reversed the damaging effects of AlCl₃ on AA and superoxide dismutase activity, markedly corrected COX and AChE activities, and moderately improved TGC. GTLE alone increased COX and AChE activities in almost all regions. GTLE reduces AlCl₃ neurotoxicity probably via antioxidative effects and improves mitochondrial and cholinergic synaptic functions through the actions of (?)‐epigallocatechin gallate and (?)‐epicatechin, compounds most abundantly found in GTLE. Our results suggest that green tea might be beneficial in Alzheimer's disease. Copyright © 2013 John Wiley & Sons, Ltd.     

Inhibitory Effect of Ethanol Extract of Magnolia officinalis on Memory Impairment and Amyloidogenesis in a Transgenic Mouse Model of Alzheimer's Disease via Regulating β‐Secretase Activity

Alzheimer's disease (AD) is the most common form of dementia and is characterized by deposition of amyloid beta (Aβ) in the brain. The components of the herb Magnolia officinalis are known to have antiinflammatory, antioxidative and neuroprotective activities. In this study we investigated the effects of ethanol extract of M. officinalis on memory dysfunction and amyloidogenesis in a transgenic mouse model of AD. Oral pretreatment of ethanol extract of M. officinalis (10 mg/kg in 0.05% ethanol) into drinking water for 3 months inhibited memory impairment and Aβ deposition in the brain of Tg2576 mice. Ethanol extract of M. officinalis also decreased activity of β‐secretase, cleaving Aβ from amyloid precursor protein (APP), and expression of β‐site APP cleaving enzyme 1 (BACE1), APP and its product, C99. Our results showed that ethanol extract of M. officinalis effectively prevented memory impairment via down‐regulating β‐secretase activity. Copyright © 2012 John Wiley & Sons, Ltd.     

连翘酯苷对东莨菪碱模型小鼠学习记忆的影响及其机制研究

目的:研究连翘酯苷对东莨菪碱模型小鼠学习记忆的影响,并探讨其作用机制,为连翘酯苷抗阿尔茨海默病研究提供数据支撑。方法:昆明种小鼠,随机分为4组,分别为正常组,东莨菪碱模型组,多奈哌齐组(3 mg·kg-1)和连翘酯苷(200 mg·kg-1)组,每组12只。各组连续给药14 d。给药第14天,东莨菪碱模型组、多奈哌齐组和连翘酯苷组给予东莨菪碱(3 mg·kg-1),腹腔注射。20 min后,进行跳台实验。同时,观察连翘酯苷对乙酰胆碱酯酶(Ach E)和环磷酸腺苷-细胞外信号调节激酶通路的影响。另设一批实验,昆明种小鼠分为4组,分别为正常组,东莨菪碱模型组,维生素E组(100 mg·kg-1)和连翘酯苷(200 mg·kg-1)组,给药14 d后,断头处死动物,检测连翘酯苷对东莨菪碱模型超氧化物歧化酶(SOD),丙二醛(MDA),单胺氧化酶(MAO)的影响。结果:跳台实验获得期和巩固期,东莨菪碱模型组与正常组比较,安全期时间比率显著下降(P0.05),连翘酯苷显著增加安全期时间比率(P0.05)。连翘酯苷显著降低东莨菪碱模型小鼠大脑皮层和海马Ach E活性(P0.05)。连翘酯苷显著升高东莨菪碱模型小鼠海马P-ERK含量,与东莨菪碱组比较,具有显著性差异(P0.05)。同时,东莨菪碱组与正常组比较,显著降低小鼠大脑皮层和海马SOD活性、升高MDA含量、升高MAO活性(P0.05)。连翘酯苷能显著升高小鼠大脑皮层和海马SOD活性、降低MDA含量和MAO活性,与东莨菪碱组比较,具有显著性差异(P0.05)。结论:连翘酯苷可提高东莨菪碱模型小鼠的学习记忆能力,其机制可能与抑制模型小鼠大脑皮层Ach E活性,促进环磷酸腺苷(c AMP)表达,活化细胞外信号调节激酶(ERK)及抗氧化有关。     

基于“毒损脑络”理论探讨川芎嗪防治阿尔茨海默病的可行性

随着老龄化程度的不断加深,阿尔茨海默病已成为我国健康卫生事业不容忽视的社会问题。在中医领域,阿尔茨海默病用于描述痴呆、健忘等认知能力缺陷的病症。经过历代医家的传承总结,“毒损脑络”理论已成为该病较为成熟的病机假说。瘀血作为其中一大致病毒邪,与现代药理学中探讨阿尔茨海默病的相关理论也有着紧密联系。川芎是临床治疗阿尔茨海默病方剂中的高频药味,川芎嗪作为其主要成分之一,具有舒张血管、抗血小板聚集、抗动脉粥样硬化、抗心肌缺血等一系列心血管系统药理作用,体现了川芎活血化瘀的功效,但尚未有充足的研究着眼于川芎嗪单一成分对阿尔茨海默病病理机制的影响。该文从中医理论与现代药理角度入手,在心血管功能、氧化应激、炎症反应、线粒体功能、胆碱能系统等多个方面探讨了川芎嗪对阿尔茨海默病相关病理及致病机制的影响,并对未来利用川芎嗪防治阿尔茨海默病做出了展望。     

镇心省睡益智方及其精油对AD模型小鼠学习记忆的影响

目的:观察镇心省睡益智方水提液及其精油对β淀粉样前体蛋白基因/早老素基因(APP/PS1)双转基因小鼠学习记忆的影响并探讨其可能机制。方法:采用APP/PS1双转基因痴呆小鼠及同月龄相同遗传背景C57BL/6JNju小鼠2种小鼠。C57BL/6JNju小鼠作为正常组,APP/PS1双转基因痴呆小鼠随机分为模型组,镇心省睡益智方精油低、高质量浓度组(12.13,48.50 mg·L~(-1)),镇心省睡益智方水提液组(0.46 g·kg~(-1)),每组12只。每天给药1次,连续给药22 d。给药结束后采用跳台实验、Morris水迷宫实验对小鼠行为学能力进行检测,采用尼氏染色观察海马CA1区神经元变化,采用硫磺素(Th S)染色观察海马DG区老年斑(SP)沉积,采用免疫组化法检测小鼠脑组织中葡萄糖转运蛋白1(GLUT1),胰岛素受体底物-1(IRS-1)的表达,采用酶联免疫吸附测定(ELISA)检测小鼠海马组织中乙酰胆碱(ACH),γ-氨基丁酸(GABA),谷氨酸(GLU)含量的变化。结果:与正常组比较,模型组小鼠跳台实验潜伏期显著缩短,错误次数显著增加(P0.01),Morris水迷宫实验定位航行逃避潜伏期明显延长(P0.05,P0.01),海马CA1区神经元出现缺失,DG区出现明显的老年斑沉积(P0.05),ACH,GLUT1含量均显著下降(P0.01),GABA,GLU水平及IRS-1的表达均显著升高(P0.01);与模型组比较,各给药组均可显著延长小鼠跳台实验潜伏期、减少跳台错误次数(P0.01),明显降低定位航行小鼠逃避潜伏期(P0.05,P0.01),可一定程度保护小鼠海马CA1区神经元,减少DG区老年斑沉积(P0.05,P0.01),明显增加小鼠脑组织中ACH,GLUT1表达(P0.05,P0.01),显著降低GABA,GLU水平及IRS-1的表达(P0.01)。结论:镇心省睡益智方水提液及其精油能够改善APP/PS1小鼠的学习记忆行为,保护神经元,增加脑组织GLUT1的表达,减少脑组织IRS-1的表达,减少老年斑沉积,升高ACH含量,降低GABA,GLU含量,可能是其防治阿尔茨海默症的机制。     

知母宁在神经退行性疾病中作用机制的研究进展

知母宁是一种具有C-糖苷和氧杂蒽酮成分的天然化合物,具有抗氧化、抗炎性损伤、提高线粒体生物能量和改善认知缺陷等多种生物活性,可以通过血脑屏障在中枢神经系统中发挥神经保护作用。对知母宁在神经退行性疾病中的作用及机制研究进展进行综述,以此探究其发挥神经保护作用的潜在分子机制,为其进一步的研究和应用提供参考。     

三焦针法对阿尔茨海默病免疫功能影响的研究

[目的]观察三焦针法对阿尔茨海默病(AD)的临床疗效及对患者免疫功能的影响。[方法]收集AD患者32例和健康老年人30例。AD组给予三焦针法,取穴膻中、中脘、气海、血海、足三里和外关,健康组不给予任何干预。利用简易精神状态检查表(MMSE)、临床痴呆量表(CDR)、老年性痴呆评估量表-认知分量表(ADAS-cog)和日常生活活动量表(ADL)评价AD患者针刺前后的认知功能、非认知功能和日常生活能力。应用流式细胞术和酶联免疫吸附法(ELISA法)检测外周血CD3~+、CD3~+CD4~+、CD3~+CD8~+T细胞数量、CD4~+/CD8~+比例、免疫球蛋白(IgG)、白介素(IL)-1β、IL-2、IL-6、干扰素-γ(IFN-γ)的水平。[结果]针刺后AD组MMSE评分升高,CDR、ADAS-cog、ADL评分降低(P0.05)。与健康组比较,AD组CD3~+、CD8~+T细胞数量减少,CD4~+T细胞数量增加(P0.05),针刺后CD3~+T细胞数量增加(P0.05)。与健康组比较,AD组IL-1β、IL-2、IL-6、IFN-γ水平增加(P0.05),IgG未见明显改变(P0.05),针刺后以上细胞因子水平降低(P0.05)。[结论]三焦针法可能通过调节AD患者的免疫功能而改善其痴呆状态。     

Evaluation of Samjunghwan,a traditional medicine,for neuroprotection against damage by amyloid-beta in rat cortical neurons

Aim of the study

Samjunghwan (SJH) is a multi-herbal traditional medicine composed of Mori Fructus, Lycii Radicis Cortex, and Atractylodis Rhizoma Alba and it is clinically applied as an anti-aging agent in neurodegenerative disorders, to promote longevity. In the present study, we evaluated the neuroprotective effect of SJH in Alzheimer's disease induced by amyloid-beta (Abeta) and examined the related pathways.

Materials and methods

To evaluate the protective effect of SJH, we conducted thiazolyl blue tetrazolium bromide, lactate dehydrogenase, and MAP-2 staining assays of primary cultured rat cortical neurons stressed by Abeta_25–35. To investigate the possible mechanism of action, we examined the Bcl-2/Bax expression ratio, mitochondrial membrane potential (Δψ_M), cytochrome C release, and caspase-3 activation, focusing on the mitochondria-mediated apoptotic pathways.

Results

SJH at concentrations of 10 and 100 μg/ml provided significant protection of rat cortical neurons from Abeta_25–35 neurotoxicity. At the maximum effective dose of 100 μg/ml, SJH significantly increased the anti-apoptotic protein (Bcl-2)/pro-apoptotic protein (Bax) ratio and inhibited Δψ_M depolarization, cytosolic cytochrome C release, and caspase-3 activation.

Conclusion

SJH appears to provide neuroprotection against mitochondria-mediated apoptotic pathways in this Abeta_25–35-induced Alzheimer's disease model.     

Genistein protects against amyloid‐beta‐induced toxicity in SH‐SY5Y cells by regulation of Akt and Tau phosphorylation

Alzheimer's disease is a neurodegenerative disorder characterized by extracellular deposition of amyloid‐β (Aβ) peptide and hyperphosphorylation of Tau protein, which ultimately leads to the formation of intracellular neurofibrillary tangles and cell death. Increasing evidence indicates that genistein, a soy isoflavone, has neuroprotective effects against Aβ‐induced toxicity. However, the molecular mechanisms involved in its neuroprotection are not well understood. In this study, we have established a neuronal damage model using retinoic‐acid differentiated SH‐SY5Y cells treated with different concentrations of Aβ_25–35 to investigate the effect of genistein against Aβ‐induced cell death and the possible involvement of protein kinase B (PKB, also termed Akt), glycogen synthase kinase 3β (GSK‐3β), and Tau as an underlying mechanism to this neuroprotection. Differentiated SH‐SY5Y cells were pre‐treated for 24 hr with genistein (1 and 10 nM) and exposed to Aβ_25–35 (25 μM), and we found that genistein partially inhibited Aβ induced cell death, primarily apoptosis. Furthermore, the protective effect of genistein was associated with the inhibition of Aβ‐induced Akt inactivation and Tau hyperphosphorylation. These findings reinforce the neuroprotective effects of genistein against Aβ toxicity and provide evidence that its mechanism may involve regulation of Akt and Tau proteins.     

Curcumin intervention for cognitive function in different types of people: A systematic review and meta‐analysis

Curcumin is a polyphenolic natural compound with diverse and attractive biological activities, which may prevent or ameliorate pathological processes underlying age‐related cognitive decline, dementia, or mood disorders. However, clinical trials and animal studies have yielded conflicting conclusions regarding its effectiveness for cognition in different individuals. The aim of this review is to meta‐analytically assess the effectiveness of curcumin for cognitive function in different types of people. A preliminary search on PubMed, Embase, Web of Science, ClinicalTrials.gov, Cochrane Library, Chinese National Knowledge Infrastructure, and Wanfang Data and China Biology Medicine disc was performed to identify randomized controlled trials investigating the effect of curcumin on cognition. Six clinical trials with a total of 289 subjects met inclusion criteria for this review. We used a random‐effects model to calculate the pooled standardized difference of means (SMD). For older adults who received curcumin, scores on measures of cognitive function (SMD = 0.33, 95% confidence interval [CI] [0.05, 0.62]; p = 0.02), occurrence of adverse events (odds ratio [OR] = 5.59, 95% CI [0.96, 36.80]; p = 0.05), and measures of depression (SMD = ?0.29, 95% CI [0.64, 0.05]; p = 0.09) indicated significant memory improvement. In patients with Alzheimer's disease (AD), scores in measures of cognition status (SMD = ?0.90, 95% CI [1.48, ?0.32]; p = 0.002) indicated that there was a trend for treated subjects to do worse than placebo‐treated subjects on the Mini‐Mental State Examination. The occurrence of adverse events (OR = 0.87, 95% CI [0.10, 7.51]; p = 0.90) was similar to those who received placebo. Due to insufficient data, it was impossible to provide a narrative account of only the outcomes for schizophrenia. Curcumin appears to be more effective in improving cognitive function in the elderly than in improving symptoms of AD and schizophrenia. Curcumin is also safe and tolerated among these individuals. Because of the small number of studies available, a funnel plot or sensitivity analysis was not possible. Further high‐quality trials with larger sample sizes or bioavailability‐improved curcumin formulations may be considered for reliable assessment.     

Ginseng Protein Reverses Amyloid Beta Peptide and H2O2 Cytotoxicity in Neurons,and Ameliorates Cognitive Impairment in AD Rats Induced by a Combination of D‐Galactose and AlCl3

Ginseng (Panax ginseng C.A. Meyer) is one of the most widely used herbal medicines worldwide. The present study evaluated the neuroprotective effects of ginseng protein (GP) and its possible mechanisms in a cellular and animal model of AD. The results demonstrated that GP (10–100 µg/mL) significantly improved the survival rate of neurons and reduced the cells' apoptosis and the mRNA expression of caspase‐3 and Bax/Bcl‐2. In addition, GP (0.1 g/kg) significantly shortened the escape latency, prolonged the crossing times and the percentage of residence time; reduced the level of Aβ_1–42 and p‐tau, the activity of T‐NOS and iNOS, and the content of MDA and NO, improved the activity of SOD, the concentration of cAMP and the protein expression of p‐PKA/PKA and ‐CREB/CREB. The results demonstrated that GP significantly inhibited Alzheimer‐like pathophysiological changes induced by Aβ_25–35 or H₂O₂ in cells or those induced by D‐gal/ Al in animals. These neuroprotective effects of GP may be associated with the cAMP/PKA/CREB pathway. Also, in combination with our previous studies, these results indicate that the anti‐AD mechanism of GP was likely to activate the CREB pathway through multiple channels. Copyright © 2016 John Wiley & Sons, Ltd.     

Guarana (Paullinia cupana Mart.) Prevents β‐Amyloid Aggregation,Generation of Advanced Glycation‐end Products (AGEs), and Acrolein‐Induced Cytotoxicity on Human Neuronal‐Like Cells

Advanced glycation end‐products (AGEs) are considered potent molecules capable of promoting neuronal cell death and participating in the development of neurodegenerative disorders such as Alzheimer's disease (AD). Previous studies have shown that AGEs exacerbate β‐amyloid (Aβ) aggregation and AGE‐related cross‐links are also detected in senile plaques. Acrolein (ACR) is an α, β‐unsaturated aldehyde found in the environment and thermally processed foods, which can additionally be generated through endogenous metabolism. The role of ACR in AD is widely accepted in the literature. Guarana (Paullinia cupana Mart.) is popularly consumed by the population in Brazil, mainly for its stimulant activity. In the present study, we showed that guarana (10, 100, and 1000 µg/mL) is able to prevent protein glycation, β‐amyloid aggregation, in vitro methylglyoxal, glyoxal, and ACR (20 μM)‐induced toxicity on neuronal‐like cells (SH‐SY5Y). Since these are considered typical AD pathological hallmarks, we propose that guarana may deserve further research as a potential therapeutic agent in such a neurodegenerative disease. Copyright © 2014 John Wiley & Sons, Ltd.     

Catalpol provides a protective effect on fibrillary Aβ1–42‐induced barrier disruption in an in vitro model of the blood–brain barrier

Excessive amyloid beta (Aβ) deposition in brain is mainly responsible for cell damage and blood–brain barrier (BBB) disruption in Alzheimer's disease (AD). Catalpol, an iridoid glucoside extracted from the root of Rehmannia glutinosa Libosch, has neuroprotective effect against AD. It is unclear whether catalpol has a protective effect on Aβ‐induced BBB leakage. We employed an immortalized endothelial cell line (bEnd.3) and astrocytes co‐culture to mimic a BBB model in vitro and investigated the effect of catalpol on BBB. We found that treatment with catalpol decreased BBB hyperpermeability induced by fibrillar Aβ_1–42. Data from western blotting showed that catalpol prevented fibrillar Aβ_1–42‐induced bEnd.3 cell apoptosis through mitochondria‐dependent and death receptor pathways; decreased the levels of matrix metalloproteinases (MMPs), MMP‐2, MMP‐9, and the receptor for advanced glycation end products; and increased the levels of tight junction proteins (ZO‐1, occludin, and claudin‐5), low‐density lipoprotein receptor‐related protein 1, and P‐glycoprotein in fibrillar Aβ_1–42‐treated bEnd.3 cells. Moreover, catalpol also enhanced soluble Aβ efflux across the fibrillar Aβ_1–42‐treated bEnd.3 cells BBB monolayer model. Altogether, our results suggest that catalpol alleviate fibrillar Aβ_1–42‐induced BBB disruption, enhance soluble Aβ clearance, and offer a feasible therapeutic application in AD treatment.     

Cognitive Ameliorating Effect of Acanthopanax koreanum Against Scopolamine‐Induced Memory Impairment in Mice

Acanthopanax koreanum Nakai (Araliaceae) is one of the most widely cultivated medicinal plants in Jeju Island, Korea, and the roots and stem bark of A. koreanum have been traditionally used as a tonic agent for general weakness. However, the use of A. koreanum for general weakness observed in the elderly, including those with declined cognitive function, has not been intensively investigated. This study was performed to investigate the effect of the ethanol extract of A. koreanum (EEAK) on cholinergic blockade‐induced memory impairment in mice. To evaluate the ameliorating effects of EEAK against scopolamine‐induced memory impairment, mice were orally administered EEAK (25, 50, 100, or 200 mg/kg), and several behavioral tasks, including a passive avoidance task, the Y‐maze, and a novel object recognition task, were employed. Besides, western blot analysis was conducted to examine whether EEAK affected memory‐associated signaling molecules, such as protein kinase B (Akt), Ca²⁺/calmodulin‐dependent protein kinase II (CaMKII), and cAMP response element‐binding protein (CREB). The administration of EEAK (100 or 200 mg/kg, p.o.) significantly ameliorated the scopolamine‐induced cognitive impairment in the passive avoidance task, the Y‐maze, and the novel object recognition task. The phosphorylation levels of both Akt and CaMKII were significantly increased by approximately two‐fold compared with the control group because of the administration of EEAK (100 or 200 mg/kg) (p < 0.05). Moreover, the phosphorylation level of CREB was also significantly increased compared with the control group by the administration of EEAK (200 mg/kg) (p < 0.05). The present study suggests that EEAK ameliorates the cognitive dysfunction induced by the cholinergic blockade, in part, via several memory‐associated signaling molecules and may hold therapeutic potential against cognitive dysfunction, such as that presented in neurodegenerative diseases, for example, Alzheimer's disease. Copyright © 2017 John Wiley & Sons, Ltd.