The emerging role of nitric oxide in the synaptic dysfunction of vascular dementia

With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.

Mendelian Randomization Study of Causal Relationship between Inflammatory Factors and Vascular Dementia and Chinese Herbal Medicines Screening for Prevention and Treatment

Objective: This study aims to examine the causal relationship between inflammatory factors and the probability of developing vascular dementia (VD) using Mendelian Randomization (MR) and Chinese herbal medicine prediction method, and to screen potential Chinese herbal medicines for the prevention and treatment of VD. Methods: Single nucleotide polymorphisms (SNPs) that exhibit a strong association with vascular dementia (VD) were identified as instrumental variables from the summary statistics of genome-wide association studies (GWAS). The primary analytical method employed was inverse variance weighting (IVW), while auxiliary analyses included the MR-Egger method, weighted median method, simple model, and weighted model. A two-way Mendelian randomization analysis was conducted to assess the causal relationship between inflammatory factors and the risk of VD, thereby identifying the key inflammatory factors involved. The MR-Egger intercept test and Cochran’s Q test were employed to assess the horizontal polymorphism and heterogeneity of instrumental variables. A sensitivity analysis was conducted by excluding one method at a time. Ultimately, based on key inflammatory factors, predictions for the prevention and treatment using traditional Chinese medicine were made, along with the screening of homologous herbal remedies. Results: Based on the results of the forward MR, the probability of developing VD was elevated when the inflammatory factors CXCL10 and CXCL5 were expressed at higher levels, whereas the probability of developing VD decreased as the expression levels of IL-13 and IL-20RA increased. These findings were supported by the assessment of pleiotropy, heterogeneity, and sensitivity. The results of the reverse MR analysis showed that there was no causal relationship between VD, as an exposure dataset, and these four inflammatory factors. According to the key inflammatory factors, 37 Chinese herbal medicines such as Siraitia grosvenorii were selected. Their characteristics including four natures, five flavors, channel tropism and treatment efficiency were cold, warm, neutral, pungent, sweet, bitter, lung meridian, spleen meridian, liver meridian, kidney meridian and clearing heat. Among them, Siraitia grosvenorii, Poria with hostwood, Perilla frutescens, and Radix Platycodi were all medicine and food homologous Chinese herbal medicines. Conclusions: The increase of CXCL10 and CXCL5 expression levels can increase the risk of VD, and the increase of IL-13 and IL-20 RA expression levels can reduce the risk of VD. Siraitia grosvenorii and other Chinese herbal medicines might be potential sources of therapeutic drugs for the treatment of VD. Medicine and food homologous Chinese herbal medicines, such as Siraitia grosvenorii, Poria with hostwood, Perilla frutescens, and Radix Platycodi, may help the elderly population with corresponding Traditional Chinese Medicine (TCM) constitutions to prevent VD.

Causal relationships between gut microbiota and dementia:A twosample,bidirectional,Mendelian randomization study

BACKGROUND Existing evidence suggests that gut microbiota represent a significant environmental risk factor for various forms of dementia,including Alzheimer's dementia,vascular dementia,and dementia in other diseases classified elsewhere.However,the exact causal relationships between gut microbiota and the different forms of dementia or their subtypes remain unclear.AIM To investigate putative causal relationships between gut microbiota and dementia or its subtypes using Mendelian randomization(MR)analysis.METHODS A bidirectional,two-sample,MR analysis was conducted utilizing publicly available gut microbiota-related genome-wide association study(GWAS)summary data from the MiBioGen consortium alongside GWAS summary statistics for dementia and its subtypes from the FinnGen consortium.Instrumental variables were selected according to the fundamental tenets of MR and their strengths were evaluated using the F-statistic.Five MR methods were employed,and the robustness of our findings was validated.To account for multiple comparisons,we applied the Bonferroni method for P-value adjustment.RESULTS We identified several gut microbiota taxa exhibiting putative causal relationships with dementia or its subtypes,potentially serving as risk or protective factors for the disease.In addition,reverse MR analysis indicated that the relative abundance of several gut microbiota taxa might be influenced by dementia or its subtypes.An exhaustive sensitivity analysis confirmed the absence of heterogeneity and horizontal pleiotropy.After applying correction for multiple testing,we observed that the order Bacillales(odds ratio:0.830,95%confidence interval:0.740-0.932,P=0.00155,Padjust=0.0311)exhibited a strong association with Alzheimer’s disease-related dementia.CONCLUSION The results suggest that gut microbiota is causally associated with dementia.Our findings provide novel insights into the pathophysiology of dementia and have important implications for its treatment and prevention.

Clinical effects of acupuncture therapy for vascular dementia

OBJECTIVE： To evaluate clinical acupuncture treatment studies for vascular dementia, as well as to collect high-quality evidence related to clinical acupuncture treatment for clinical diagnosis. DATA SOURCES： PubMed database （1966-2010）, Embase database （1986-2010）, Cochrane Library （Issue 1,2010）, Chinese Biomedical Literature Database （1979-2010）, China HowNet database （1979-2010）, VlP Journals Database （1989-2010）, and Wanfang database （1998-2010） were analyzed by computer.

Therapeutic effects of dental pulp stem cells on vascular dementia in rat models

Dental pulp stem cells are a type of adult stem cells with strong proliferative ability and multi-differentiation potential. There are no studies on treatment of vascular dementia with dental pulp stem cells. In the present study, rat models of vascular dementia were established by two-vessel occlusion, and 30 days later, rats were injected with 2 × 10^(7) dental pulp stem cells via the tail vein. At 70 days after vascular dementia induction, dental pulp stem cells had migrated to the brain tissue of rat vascular dementia models and differentiated into neuronlike cells. At the same time, doublecortin, neurofilament 200, and Neu N m RNA and protein expression levels in the brain tissue were increased, and glial fibrillary acidic protein m RNA and protein expression levels were decreased. Behavioral testing also revealed that dental pulp stem cell transplantation improved the cognitive function of rat vascular dementia models. These findings suggest that dental pulp stem cell transplantation is effective in treating vascular dementia possibly through a paracrine mechanism. The study was approved by the Animal Ethics Committee of Harbin Medical University(approval No. KY2017-132) in 2017.

Transcatheter treatment of atherosclerotic lesions of the brain complicated by vascular dementia development

The research focuses on the effectiveness of transluminal laser revascularization of the brain in the treatment of atherosclerotic lesions accompanied by vascular dementia development. 1125 patients aged from 29 to 81 (average age 75) suffering from various kinds of atherosclerotic lesions of cerebral vessels were examined during the research. The examination plan included: computed tomography of the brain (CT), magnetic resonance imaging (MRI), scintigraphy of the brain (SG), rheoencephalography (REG), cerebral multi-gated angiography (MUGA). 665 (59.11%) patients suffered from diseases accompanied by the development of vascular dementia. To perform transcatheter treatment, 639 patients were selected: Group 1 (CDR-1)—352 patients, Group 2 (CDR-2)—184 patients, Group 3 (CDR-3)—103 patients. To conduct revascularization of main intracranial arteries high-energy laser systems were used;for revascularization of the distal intracranial branches low-energy laser systems were used. The clinical outcome depended on the severity of dementia and the timing of the intervention. A good clinical outcome in Group 1 was obtained in 281 (79.82%) cases, in Group 2 in 81 (44.02%) cases, in Group 3 in 9 (8.73%) cases. A satisfactory clinical outcome in Group 1 was obtained in 53 (15.34%) cases, in Group 2 in 62 (33.70%) cases, in Group 3 in 31 (30.09%) cases. A relatively satisfactory clinical outcome in Group 1 was obtained in 17 (4.83%) cases, in Group 2 in 41 (22.28%) cases, in Group 3 in 63 (61.16%) cases. No negative effect was observed after the intervention. Evaluating the data obtained it can be concluded that the method of transluminal laser revascularization of cerebral blood vessels is an effective one for the treatment of atherosclerotic lesions of the brain accompanied by dementia.

Pathogenesis, Rehabilitation Assessment, Treatment Status, and Research Progress of Vascular Dementia

Given the global trends in population aging,the prevalence of vascular dementia(VD)is increasing year by year.VD has become the second most common type of dementia and can seriously threaten the quality of life of patients.Since VD is preventable,it is important to study VD clinically in order to improve the prognosis of patients.In recent years,a large number of studies have been carried out at home and abroad,focusing on the pathogenesis,rehabilitation assessment,and treatment of VD.This article is a concise overview of these studies.

Influence of folic acid and vitamin B12 combined therapy on plasma Hcy, inflammatory factor levels and blood vessels endothelial function in patients with vascular dementia and type H hypertension

Objective:To investigate influence of folic acid and vitamin B12 combined therapy on plasma homocysteine (Hcy) level, blood vessels endothelial function and inflammatory factors in patients with vascular dementia and type H hypertension.Methods:100 cases of patients with vascular dementia and type H hypertension accorded with the inclusion criteria were selected as research objects. They were randomly divided as the control group and the therapeutic group, 50 cases each. For control group, Enalapril tablets were administered by mouth for treatment. For therapeutic group, folic acid and vitamin B12 treatment were provided on the basis of treatment for control group. Treatments were continued for 12 weeks. Plasma Hcy levels, inflammatory factors [(interleukin-6 (IL-6), interleukin-8 (IL-8) and hypersensitive C reaction protein (hs-CRP)], blood vessels endothelial function indexes variation in patients before and after treatment were observed and detected.Results:Plasma Hcy, IL-6, IL-8 and hs-CRP levels in two groups of patients after treatment were significantly decreased comparing with the same group before treatment, and the above index levels in therapeutic group after treatment were significantly lower than control group (P<0.05);For comparison of blood vessels endothelial function indexes in the patients, NO levels in two groups after treatment were increased in various degrees, and endothelin-1 (ET-1) were decreased. The differences between levels of the two indexes in therapeutic group before and after treatment were significant, and levels after treatment in therapeutic group were significantly better than in control group (P<0.05). While variations of the differences in control group before and after treatment were not significant (P>0.05);After treatment, diastolic pressure and systolic pressure in the two groups of patients were significantly improved comparing with before treatment (P<0.05). However, after treatment, the differences of levels between therapeutic group and control group were not significant (P>0.05). MMSE score in therapeutic group after treatment was significantly higher than before treatment, and significantly higher than in control group (P<0.05).Conclusions: Combined therapy of folic acid and vitamin B12 for treating vascular dementia with type H hypertension could effectively decrease plasma Hcy and inflammatory factor levels, and improve blood vessels endothelial function and dementia degree on patients. It has certain clinical value which deserves to be promoted.

A meta-analysis of Chinese herbal medicines for vascular dementia

OBJECTIVE： To investigate the efficacy and safety of Chinese herbal medicines in the treatment of patients with vascular dementia. DATA RETRIEVAL： We retrieved publications from Cochrane Library （2004 to July 2011）, PubMed （1966 to July 2011）, the Chinese Science and Technique Journals Database （1977 to July 2011）, the China National Knowledge Infrastructure （1979 to July 2011）, Google Scholar （July 2011）, and the Chinese Biomedical Database （1977 to July 2011） using the key words ＂Chinese medicine OR Chinese herbal medicine＂ and ＂vascular dementia OR mild cognition impair OR multi-infarct dementia OR small-vessel dementia OR strategic infarct dementia OR hypoperfusion dementia OR hemorrhagic dementia OR hereditary vascular dementia＂. SELECTION CRITERIA： Randomized controlled trials comparing Chinese herbal medicines with placebo/western medicine in the treatment of patients with vascular dementia were included. Diagnostic standards included Diagnostic and Statistical Manual of Mental Disorders-IV, and National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherche et I＇Enseignement en Neurosciences. Two participants independently conducted literature screening, quality evaluation and data extraction. The quality of each trial was assessed according to the Cochrane Reviewers＇ Handbook 5.0. MAIN OUTCOME MEASURES： Effective rate, Mini-Mental State Examination scores, Hasegawa Dementia Scale scores, and incidence of adverse reactions. RESULTS： We identified 1 143 articles discussing the effects of Chinese medicine on vascular dementia. Thirty-one of these were included in the analysis. These studies involved a total of 2 868 participants （1 605 patients took Chinese medicine decoctions （treatment group）; 1 263 patients took western medicine or placebo）. The results of our meta-analysis revealed that Chinese herbal remedies in the treatment group were more efficacious than the control intervention （relative risk （RR） = 1.27; 95% confidence interval （C/）： 1.18-1.38, P 〈 0.01）. Mini-Mental State Examination scores were higher in patients taking Chinese herbal medicines than in those in the control group （weighted mean difference （WMD） = 2.83; 95%CI： 2.55-3.12, P 〈 0.01）. Patients in the treatment group showed better disease amelioration than those in the control group （Hasegawa Dementia Scale scores; WMD = 2.41, 95%CI： 1.48-3.34, P 〈 0.01）. There were also considerably fewer adverse reactions among those in the treatment group compared with those in the control group （RR = 0.20, 95%CI： 0.08-0.47, P 〈 0.01）. CONCLUSION： Chinese herbal medicine appears to be safer and more effective than control measures in the treatment of vascular dementia. However, the included trials were generally low in quality. More well-designed, high-quality trials are needed to provide better evidence for the assessment of the efficacy and safety of Chinese medicines for vascular dementia.

Recommendation for and comparison of three types of dementia： Alzheimer’s disease, subcortical ischemic vascular dementia, and mixed dementia

With the progress in global demography of aging, dementia has become a great world health-care issue that require urgent attention and settlement. Demen-tia can arise from a variety of factors, such as neuronal degeneration for Alzheimer’s disease （AD）, vascular risk factors and multiple infarcts for vascular dementia （VaD）, and both degeneration and vascular factors for mixed de-mentia （MD）. Pathophysiology of AD includes the amy-loid and tau protein hypothesis, and infammation-related mechanisms are also widespread mentioned. Subcortical ischemic vascular dementia （SIVD）, a subtype of VaD, is commonly caused by complete or incomplete lacunar infarction of VaD pathology. MD involves both degenera-tion and vascular factors, and the interaction between the two results in the complication of the pathological mech-anism and clinical phenotype. The clinical manifestationsof AD are often divided into four stages according to the progress of the disease, while the phenotypes of SIVD usually has two categories. As for MD, the phenotypes are complex and diverse. Several clinical studies showedthat its symptoms and signs are more similar to SIVD than AD. This article aims to analyze and compare the differ-ent aspects of the three kinds of dementia.

A pancreatic player in dementia:pathological role for islet amyloid polypeptide accumulation in the brain

Type 2 diabetes mellitus patients have a markedly higher risk of developing dementia.While multiple factors contribute to this predisposition,one of these involves the increased secretion of amylin,or islet amyloid polypeptide,that accompanies the pathophysiology of type 2 diabetes mellitus.Islet amyloid polypeptide accumulation has undoubtedly been implicated in various forms of dementia,including Alzheimer’s disease and vascular dementia,but the exact mechanisms underlying islet amyloid polypeptide’s causative role in dementia are unclear.In this review,we have summarized the literature supporting the various mechanisms by which islet amyloid polypeptide accumulation may cause neuronal damage,ultimately leading to the clinical symptoms of dementia.We discuss the evidence for islet amyloid polypeptide deposition in the brain,islet amyloid polypeptide interaction with other amyloids implicated in neurodegeneration,neuroinflammation caused by islet amyloid polypeptide deposition,vascular damage induced by islet amyloid polypeptide accumulation,and islet amyloid polypeptide-induced cytotoxicity.There are very few therapies approved for the treatment of dementia,and of these,clinical responses have been controversial at best.Therefore,investigating new,targetable pathways is vital for identifying novel therapeutic strategies for treating dementia.As such,we conclude this review by discussing islet amyloid polypeptide accumulation as a potential therapeutic target not only in treating type 2 diabetes mellitus but as a future target in treating or even preventing dementia associated with type 2 diabetes mellitus.

Panax ginseng extract attenuates neuronal injury and cognitive deficits in rats with vascular dementia induced by chronic cerebral hypoperfusion

Panax ginseng is a slow-growing perennial plant.Panax ginseng extract has numerous biological activities,including antitumor,anti-inflammatory and antistress activities.Panax ginseng extract also has a cognition-enhancing effect in rats with alcohol-induced memory impairment.In this study,we partially occluded the bilateral carotid arteries in the rat to induce chronic cerebral hypoperfusion,a wellknown model of vascular dementia.The rats were then intragastrically administered 50 or 100 mg/kg Panax ginseng extract.Morris water maze and balance beam tests were used to evaluate memory deficits and motor function,respectively.Protein quantity was used to evaluate cholinergic neurons.Immunofluorescence staining was used to assess the number of glial fibrillary acidic protein-positive cells.Western blot assay was used to evaluate protein levels of vascular endothelial growth factor,basic fibroblast growth factor,Bcl-2 and Bax.Treatment with Panax ginseng extract for 8 weeks significantly improved behavioral function and increased neuronal density and VEGF and b FGF protein expression in the hippocampal CA3 area.Furthermore,Panax ginseng extract reduced the number of glial fibrillary acidic protein-immunoreactive cells,and it decreased apoptosis by upregulating Bcl-2 and downregulating Bax protein expression.The effect of Panax ginseng extract was dose-dependent and similar to that of nimodipine,a commonly used drug for the treatment of vascular dementia.These findings suggest that Panax ginseng extract is neuroprotective against vascular dementia induced by chronic cerebral hypoperfusion,and therefore might have therapeutic potential for preventing and treating the disease.

Autophagy activation aggravates neuronal injury in the hippocampus of vascular dementia rats

It remains unclear whether autophagy affects hippocampal neuronal injury in vascular dementia. In the present study, we investigated the effects of autophagy blockade on hippocampal neuro- nal injury in a rat model of vascular dementia. In model rats, hippocampal CA1 neurons were severely damaged, and expression of the autophagy-related proteins beclin-1, cathepsin B and microtubule-associated protein 1 light chain 3 was elevated compared with that in sham-operated animals. These responses were suppressed in animals that received a single intraperitoneal injection of wortmannin, an autophagy inhibitor, prior to model establishment. The present results confirm that autophagy and autophagy-related proteins are involved in the pathological changes of vascular dementia, and that inhibition of autophagy has neuroprotective effects.

Effects of repetitive transcranial magnetic stimulation on cognitive function and cholinergic activity in the rat hippocampus after vascular dementia

Repetitive transcranial magnetic stimulation （rTMS） is a non-invasive treatment that can enhance the recovery of neurological function after stroke. Whether it can similarly promote the recovery of cognitive function after vascular dementia remains unknown, In this study, a rat model for vascular dementia was established by the two-vessel occlusion method. Two days after injury, 30 pulses of rTMS were ad- ministered to each cerebral hemisphere at a frequency of 0.5 Hz and a magnetic field intensity of 1,33 T. The Morris water maze test was used to evaluate learning and memory function. The Karnovsky-Roots method was performed to determine the density of cholinergic neurons in the hippocampal CA1 region. Immunohistochemical staining was used to determine the number of brain-derived neurotroph- ic factor （BDNF）-immunoreactive cells in the hippocampal CA1 region, rTMS treatment for 30 days significantly improved learning and memory function, increased acetylcholinesterase and choline acetyltransferase activity, increased the density of cholinergic neurons, and increased the number of BDNF-immunoreactive cells. These results indicate that rTMS can ameliorate learning and memory deficiencies in rats with vascular dementia, The mechanism through which this occurs might be related to the promotion of BDNF expression and subsequent restoration of cholinergic system activity in hippocampal CA 1 region.

Resveratrol improves cognition and reduces oxidative stress in rats with vascular dementia

Resveratrol possesses beneficial biological effects, which include anti-oxidant, anti-inflammatory and anti-carcinogenic properties. Recently, resveratrol has been shown to exhibit neuroprotective effects in models of Parkinson＇s disease, cerebral ischemia and Alzheimer＇s disease. However, its effects on vascular dementia remain unclear. The present study established a rat model of vascular dementia using permanent bilateral common carotid artery occlusion. At 8-12 weeks after model induction, rats were intragastrically administered 25 mg/kg resveratrol daily. Our results found that resveratrol shortened the escape latency and escape distances in the Morris water maze, and pro- longed the time spent percentage and swimming distance percentage in the target quadrant during the probe test, indicating that resveratrol improved learning and memory ability in vascular dementia rats. Further experiments found that resveratrol decreased malonyldialdehyde levels, and increased superoxide dismutase activity and glutathione levels in the hippocampus and cerebral cortex of vascular dementia rats. These results confirmed that the neuroprotective effects of resveratrol on vascular dementia were associated with its anti-oxidant properties.

Effect of glycosides of Cistanche on the expression of mitochondrial precursor protein and keratin type Ⅱ cytoskeletal 6A in a rat model of vascular dementia

Glycosides of Cistanche（GC）is a preparation used extensively for its neuroprotective effect against neurological diseases,but its mechanisms of action remains incompletely understood.Here,we established a bilateral common carotid artery occlusion model of vascular dementia in rats and injected the model rats with a suspension of GC（10 mg/kg/day,intraperitoneally）for 14 consecutive days.Immunohistochemistry showed that GC significantly reduced p-tau and amyloid beta（Aβ）immunoreactivity in the hippocampus of the model rats.Proteomic analysis demonstrated upregulation of mitochondrial precursor protein and downregulation of keratin type II cytoskeletal6A after GC treatment compared with model rats that had received saline.Western blot assay confirmed these findings.Our results suggest that the neuroprotective effect of GC in vascular dementia occurs via the promotion of neuronal cytoskeleton regeneration.

Hippocampal expression of synaptic structural proteins and phosphorylated cAMP response element-binding protein in a rat model of vascular dementia induced by chronic cerebral hypoperfusion

The present study established a rat model of vascular dementia induced by chronic cerebral hypoperfusion through permanent ligation of bilateral common carotid arteries.At 60 days after modeling,escape latency and swimming path length during hidden-platform acquisition training in Morris water maze significantly increased in the model group.In addition,the number of accurate crossings over the original platform significantly decreased,hippocampal CA1 synaptophysin and growth-associated protein 43 expression significantly decreased,cAMP response element-binding protein expression remained unchanged,and phosphorylated cAMP response element-binding protein expression significantly decreased.Results suggested that abnormal expression of hippocampal synaptic structural protein and cAMP response element-binding protein phosphorylation played a role in cognitive impairment following chronic cerebral hypoperfusion.

Improving cognitive impairment by Tongxinluo via inhibiting expression of beta-secretase 1/beta-amyloid peptide in experimental vascular dementia

BACKGROUND： Tongxinluo has been clinically proven to be effective in improving memory and cognitive function in patients with post-stroke vascular dementia. Is the mechanism related to the deposition of beta-amyloid peptide （A β ） in hippocampus？ OBJECTIVE： To observe the effect of Tongxinluo on cognitive impairment in a mouse model with vascular dementia and the changes of A β deposition and β -secretase 1 （BACE1） expression. DESIGN： Randomized controlled study. SETTING： State Key Laboratory of Pharmaceutical Biotechnology of Nanjing University and Affiliated Drum Tower Hospital of Nanjing University Medical School. MATERIALS： The experiment was carried out in the State Key Laboratory of Pharmaceutical Biotechnology of Nanjing University and Affiliated Drum Tower Hospital of Nanjing University Medical School from March 2006 to January 2007. A total of 36 healthy Kunming mice, 18 of each gender, were chosen. The study was conducted in accordance with the National Regulations of Experimental Animal Administration, and all animal experiments were approved by the Committee of Experimental Animal Administration of Nanjing University. Tongxinluo was provided by Shijiazhuang Yiling Pharmaceutical Co., Ltd. METHODS： All mice were randomly divided into 6 groups, including naive control （n=6）, sham-operated control （n=6） and experimental groups treated with different doses of Tongxinluo （0.2, 0.4, and 0.6 g/kg/d; n=6 for each group） or vehicle （n=6）. Five groups were subjected to bilateral common carotid arteries （2-VO） occlusion to produce a vascular dementia model （no occlusion was performed in sham-operated group）. The mice in the Tongxinluo treatment groups were intragastricly administered daily with a Tongxinluo suspension （40 g/L in distilled water） at doses of 0.2, 0.4 or 0.6 g/kg/d from day 1 to day 30 post-surgery. The animals in vehicle, sham-operated and naive groups were administered an equal volume of distilled water. MAIN OUTCOME MEASURES： ①Escape latency time determined in all groups of mice before and after 2-VO occlusion by Morris water maze. ②Changes in BACEI mRNA expression in the hippocampi of mice among the six groups by RT-PCR assay, and BACEI and A β protein expression in the hippocampi of mice by Western blot. RESULTS： All 36 mice were involved in the final analysis.① No difference was detected in escape latency time to a hidden platform among all groups in water maze test before surgery （P 〉 0.05） At 30 days after 2-VO occlusion, the vehicle animals exhibited a significantly longer latency in finding the hidden platform compared to that of sham-operated and naive animals （P 〈 0.01）. The prolonged escape latency was significantly reduced by oral administration of 0.4 g or 0.6 kg/day （P 〈 0.01, P 〈 0.05）. BACEI mRNA and protein expression in vehicle animals were much higher than in sham-operated and naive animals （P 〈 0.01）. The ischemia-induced increases in BACE1 mRNA and protein level were attenuated by all three doses of Tongxinluo treatment （P 〈 0.01）, and the 0.4 g/kg/d treatment was the most effective. A β protein expression in vehicle animals after 2-VO occlusion were much higher than in sham-operated and naive animals （P 〈 0.01）. 2-VO occlusion-induced A β generation was significantly attenuated by all doses of Tongxinluo treatment, with the most effective dose being 0.4 g/kg/d （P 〈 0.01）. CONCLUSION： BACE1 mRNA levels and protein levels of BACEI and A β are reduced in the hippocampi of vascular dementia model mice by all three doses of Tongxinluo treatment, with the most effective dose being 0.4 g/kg/d. The results suggest that inhibition of post-ischemia BACEI expression and A β generation in brain might underlie Tongxinluo＇s effects in improving cognitive impairment.

Puerarin decreases hypoxia inducible factor-1 alpha in the hippocampus of vascular dementia rats

In this study, a rat vascular dementia model was established by permanent bilateral common carotid arterial occlusion. Rats were intraperitoneally injected with puerarin 3 days before modeling, for 45 successive days. Results demonstrated that in treated animals hippocampal structures were clear, nerve cells arranged neatly, and cytoplasm was rich in Nissl bodies. The number of cells positive for hypoxia inducible factor-1 alpha, erythropoietin and endothelial nitric oxide synthase was reduced; and the learning and memory abilities of rats were significantly improved. Our experimental findings indicate that puerarin can significantly improve learning and memory in a vascular dementia model, and that the underlying mechanism may be associated with the regulation of the expression of hypoxia inducible factor-1 alpha.

Kongsheng Zhenzhong pill's effect on the learning and memory ability and its neuroprotective effects in vascular dementia rats

Clinical reports have demonstrated that the Kongsheng Zhenzhong pill （KSZZP）, a classical prescription deriving from Valuable Prescription for Emergencies, has good therapeutic effects on vascular dementia. However, the mechanisms that mediate its effects remain unclear. In this study, the expression of N-methyI-D-aspartate receptor 1 mRNA, the content of nitric oxide, and the concentration of calcium in neurons was determined with in situ hybridization, spectrophotometry and flow cytometry, respectively. In addition, the expressions of N-methyI-D-aspartate receptor 1, nerve growth factor protein, and glial cell line-derived neurotrophic factor protein were detected with immunohistochemistry. We found that KSZZP could significantly decrease the expression of N-methyI-D-aspartate receptor 1 mRNA and protein, the content of nitric oxide, and the concentration of calcium in neurons. KSZZP also increased the expression of nerve growth factor and glial cell line-derived neurotrophic factor protein in the hippocampus CA1 region and in the cerebral cortex. Morris water maze and passive avoidance tests verified that KSZZP ameliorated the cognitive impairments of vascular dementia rats. Moreover, the KSZZP-induced improvements in the cognitive functions of vascular dementia rats were correlated with both inhibition of N-methyl-D-aspartate-induced excitable neurotoxicity and elevation of neurotrophic factor expression.