电针对阿尔海茨默病模型大鼠跳台试验潜伏期和错误次数的影响及其相关机制研究

目的:探讨电针对阿尔海茨默病模型大鼠运动能力的影响。方法:将通过筛选的模型大鼠分为空白对照组、模型对照组、模型组、西药组和电针组5组,电针组给予电针治疗,西药给予哈伯因灌液,其余三组每日给予相同容量的生理盐水,共治疗6周。观察各组大鼠跳台试验潜伏期和错误次数。结果:造模后模型组与空白组比较逃避潜伏期缩短,错误次数增多(P<0.01),电针组、西药组治疗后潜伏期较长,错误次数较少(P<0.05);治疗后,电针组、西药对照组较模型组海马CA1区tau蛋白表达表达水平显著增多(P<0.01)。结论:电针对AD大鼠记忆能力的恢复有重要的调节作用。

Development of a Zebrafish Model for Rapid Drug Screening against Alzheimer＇s Disease

Alzheimer＇s disease, the leading cause of dementia in the elderly, is a complex neurodegenerative disorder which leads to a progressive decline in cognitive functions. A rapid screening model is highly demanded for identification and evaluation of novel anti-Alzheimer＇s disease drugs from a large numbers of compounds. Until now, numerous studies utilized zebrafish model for drug discovery. Since aluminum can induce a similar biological activity in zebrafish as in Alzheimer patients, in this study, we developed a novel animal model using 3 to 5 day post-fertilization larval zebrafish by optimizing the doses and duration of aluminum chloride exposure. Six anti-Alzheimer＇s disease drugs with a variety of mechanisms were tested to validate the newly developed zebrafish model. Importantly, Rivastigmine, ThT, Flurbiprofen and AM-117 could increase the value of Dyskinesia Recovery Rate by 53.4-64%, 169.4-200%, 54.5-96% and 70.9-121%, respectively. Rivastigmine, Memantine, ThT, Flurbiprofen, Rosiglitazone and AM-117 improved the value of Response Efficiency by 86.6-175.1%, 28.2-66.6%, 127.2-236.5%, 118.3-323.7%, 26.6-140.8% and 70.2-161.4%, respectively. Our results suggest that the zebrafish model developed in this study could be a useful tool for high throughput screening of potential novel anti-Alzheimer＇s disease leading compounds targeting acetylcholinesterase, N-methyl-D-aspartic acid receptor, γ-secretase, peroxisome proliferator-activated receptor-γand amyloid-β.

Evaluation of the prevention and treatment effects of acupuncture-moxibustion for Alzheimer disease based on various mouse models

Objective:To evaluate the prevention and treatment effects of acupuncture-moxibustion for Alzheimer disease(AD)based on various AD mouse models.Methods:Several representative types of mouse models were selected according to the pathophysiological causes of AD,including senescence accelerated mouse/prone(SAMP)mice,soluble amyloid-βprotein(Aβ)injection mice/rats,amyloid precursor protein(APP)transgenic mice,and APP/PS1 double transgenic mice.Through the observation of behavioral changes and analysis of core items,the possible mechanisms of acupuncture-moxibustion in preventing and treating AD were explored.Results:Acupuncture-moxibusiton therapy can improve AD mice's cognitive dysfunction;the major action mechanisms including increasing cerebral blood flow,improving the expressions of vital proteins in the hippocampus,preventing neuron cell apoptosis,promoting the clearance of Aβdeposition,activating autophagy pathway to reduce memory deficits and regulating the metabolisms of brain-derived neurotrophic factor,tyrosine kinase receptor B,N-acetylaspartate and glutamic acid.Conclusion:Although the optimal mouse model is not determined,it is sure that acupuncture-moxibustion therapy can improve cognitive function.A more suitable AD animal model should be duplicated in order to better explore the inherent action mechanism of acupuncture-moxibustion in preventing and treating AD.

Biochemical and behavioral characterization of the double transgenic mouse model (APPswe/PS1dE9) of Alzheimer’s disease

Objective The double transgenic mouse model （APPswe/PSldE9） of Alzheimer＇s disease （AD） has been widely used in experimental studies. β-Amyloid （Aβ） peptide is excessively produced in AD mouse brain, which affects synaptic function and the development of central nervous system. However, little has been reported on characterization of this model. The present study aimed to characterize this mouse AD model and its wild-type counterparts by biochemical and functional approaches. Methods Blood samples were collected from the transgenic and the wild-type mice, and radial arm water maze behavioral test was conducted at the ages of 6 and 12 months. The mice were sacrificed at 12-month age. One hemisphere of the brain was frozen-sectioned for immunohistochemistry and the other hemisphere was dissected into 7 regions. The levels ofAβ1-40, Aβ1-42 and 8-hydroxydeoxyguanosine （8-OHdG） in blood or/and brain samples were analyzed by ELISA. Secretase activities in brain regions were analyzed by in vitro assays. Results The pre-mature death rate of transgenic mice was approximately 35% before 6-month age, and high levels of Aβ1-40 and Aβ1-42 were detected in these dead mice brains with a ratio of 1 ： 1 0. The level of blood-borne Aβ at 6-month age was similar with that at 12-month age. Besides, Aβ1-40 level in the blood was significantly higher than Aβ1-42 level at the ages of 6 and 12 months （ratio 2.37：1）. In contrast, the level of Aβ1-42 in the brain （160.6 ng/mg protein） was higher than that of Aβ1-40 （74 ng/mg protein） （ratio 2.17：1）. In addition, the levels of Aβ1-40 and Aβ1-42 varied markedly among different brain regions. Aβ1-42 level was significantly higher than Aβ1-40 level in cerebellum, frontal and posterior cortex, and hippocampus. Secretase activity assays did not reveal major differences among different brain regions or between wild-type and transgenic mice, suggesting that the transgene PS1 did not lead to higher 7-secretase activity but was more efficient in producing Aβ1-42 peptides. 8-OHdG, the biomarker of DNA oxidative damage, showed a trend of increase in the blood of transgenic mice, but with no significant difference, as compared with the wild-type mice. Behavioral tests showed that transgenic mice had significant memory deficits at 6-month age compared to wild-type controls, and the deficits were exacerbated at 12-month age with more errors. Conclusion These results suggest that this mouse model mimics the early-onset human AD and may represent full-blown disease at as early as 6-month age for experimental studies.

Effect of Yizhitongxuan decoction on learning and memory ability,Gαq/11 expression and Na^+-K^+-ATP enzyme activity in rat models of Alzheimer's Disease

OBJECTIVE: To study the effects of Yizhitongxuan decoction on learning and memory abilities, Gαq/11expression and Na+-K+-ATPenzymeactivityin rat models of Alzheimer's disease(AD) caused by injecting Aβ25-35 into the hippocampus.METHODS: Ninety male Wistar rats(age ≥10 months)were selected and injected with Aβ25-35 into their hippocampi to establish model animals,which were randomly divided into six groups including a sham-operated group(blank group), a model group, a donepezil HCL group(Western Medicinegroup),and ahigh/general/dilute concentrations of Yizhitongxuan decoction groups(TCMⅠⅡⅢgroup).The Morris watermaze was used to examine the learning and memory abilities of rats in each group by place navigation and spatial probe tests.Then, the rats were sacrificed to collect the hippocampi for biochemical tests, using western blotting to detect the expression of Gαq/11 and an ultramicro Na+-K+-ATP enzyme kit to measure Na+-K+-ATP enzyme activity.RESULTS:Yizhitongxuan decoction improved model rats' learning and memory abilities, and increased the expression of Gαq/11 in the hippocampus and the level of Na+-K+-ATP enzyme activity in braintissue.CONCLUSION: Yizhitongxuan decoction could improve model rats' learning and memory abilities,and had a regulating effect on the expression of Gαq/11and Na+-K+-ATP enzyme activity.

Ameliorating effect of Zhizi(Fructus Gardeniae) extract and its glycosides on scopolamine-induced memory impairment

OBJECTIVE： To study the chemical constituents of Zhizi （Fructus Gardeniae） and their antiamnesic ef- fect in a mouse model of Alzheimer＇s disease. METHODS： Ameliorating effects of the extracts, fractions and constituents on scopolamine-in- duced memory impairment in vivo using a passive avoidance task system and their inhibitory activi- ties on acetylcholinesterase （ACHE） in vitro were ex- amined. The isolation of components was per- formed by chromatographic techniques and their structures were identified on the basis of spectral analysis. RESULTS： Activity-guided fractionation of the total extracts resulted in the isolation of two glycosides, geniposide and cr0cin from the n-butanol fraction and genipin and crocetin from the ethylacetate fraction. Among the fractions tested, n-butanol fraction showed the strongest AChE inhibition （43.4% at a final dose of 0.03 mg/mL） and also ex- hibited outstanding efficacy （65.9% at a dose of2.50 mg/kg） in an experimental model of amnesia. Geniposide showed a 22.8% AChE inhibitory activi- ty and a potent ameliorating effect on scopol- amine-induced memory impairment in amnesic mice of 93.4% as compared to the control group. CONCLUSION： Geniposide, a main constituent of gardenia should be considered a candidate for fur- ther clinical study for the purpose of developing a cognition activator and its mechanism of action may be mediated, at least in part, by the acetylcho- line enhancing cholinergic nervous system.

Effects of Compound Danshen tablets(复方丹参片) on spatial cognition and expression of brain β-amyloid precursor protein in a rat model of alzheimer's disease

OBJECTIVE:To observe the effects of Compound Danshen Tablets(CDST) on spatial cognition and expression of brain b-amyloid precursor protein(β-APP) in a rat model of Alzheimer's disease.METHODS:The rat model of Alzheimer's disease(AD) was established using D-galactose to cause subacute aging combined with Meynert nucleus damage.Rat behavior was monitored using the Morris water maze,and the expression of β-APP in rat brain tissue was detected via immunohistochemistry.RESULTS:CDST significantly improved spatial cognition and decreased β-APP expression in the cortex and hippocampus(P<0.05,P<0.01).CONCLUSIONS:CDST can significantly improve spatial cognition in a rat model of AD.This observation is possibly related to a reduction in β-APP ex-pression in the rat brain.