Neurovascular Correlates of Cobalamin, Folate, and Homocysteine in Dementia.

BACKGROUND: Cobalamin (Cbl) and folate are common supplements clinicians prescribe as an adjuvant therapy for dementia patients, on the presumption of their neurotrophic and/or homocysteine (Hcy) lowering effect. However, the treatment efficacy has been found mixed and the effects of Cbl/folate/Hcy on the human brain remain to be elucidated. OBJECTIVE: To explore the neurovascular correlates of Cbl/folate/Hcy in Alzheimer's disease (AD) and subcortical ischemic vascular dementia (SIVD). METHODS: Sixty-seven AD patients and 57 SIVD patients were prospectively and consecutively recruited from an outpatient clinic. Multimodal 3-Tesla magnetic resonance imaging was performed to quantitatively evaluate cerebral blood flow (CBF) and white matter integrity. The relationship between neuroimaging metrics and the serum levels of Cbl/folate/Hcy was examined by using the Kruskal-Wallis test, partial correlation analysis, and moderation analysis, at a significance level of 0.05. RESULTS: As a whole, CBF mainly associated with Cbl/folate while white matter hyperintensities exclusively associated with Hcy. As compared with AD, SIVD exhibited more noticeable CBF correlates (spatially widespread with Cbl and focal with folate). In SIVD, a bilateral Cbl-moderated CBF coupling was found between medial prefrontal cortex and ipsilateral basal ganglia, while in the fronto-subcortical white matter tracts, elevated Hcy was associated with imaging metrics indicative of increased injury in both axon and myelin sheath. CONCLUSIONS: We identified the neurovascular correlates of previously reported neurotrophic effect of Cbl/folate and neurotoxic effect of Hcy in dementia. The correlates exhibited distinct patterns in AD and SIVD. The findings may help improving the formulation of supplemental Cbl/folate treatment for dementia.

Exploring the Oxidative Stress Mechanism of Buyang Huanwu Decoction in Intervention of Vascular Dementia Based on Systems Biology Strategy.

OBJECTIVE: To explore the oxidative stress mechanism of modified Buyang Huanwu decoction (MBHD) in intervention of vascular dementia (VD) based on systems biology strategy. METHODS: In this study, through the reverse virtual target prediction technology and transcriptomics integration strategy, the active ingredients and potential targets of MBHD treatment of VD were analyzed, and the drug-disease protein-protein interaction (PPI) network was constructed. Then, bioinformatics analysis methods are used for Gene Ontology (GO) enrichment analysis and pathway enrichment analysis, and finally find the core biological process. After that, in animal models, low-throughput technology is used to detect gene expression and protein expression of key molecular targets in oxidative stress-mediated inflammation and apoptosis signaling pathways to verify the mechanism of MBHD treatment of VD rats. Finally, the potential interaction relationship between MBHD and VD-related molecules is further explored through molecular docking technology. RESULTS: There are a total of 54 MBHD components, 252 potential targets, and 360 VD genes. The results of GO enrichment analysis and pathway enrichment analysis showed that MBHD may regulate neuronal apoptosis, nitric oxide synthesis and metabolism, platelet activation, NF-κB signaling pathway-mediated inflammation, oxidative stress, angiogenesis, etc. Among them, SIRT1, NF-κB, BAX, BCL-2, CASP3, and APP may be important targets for MBHD to treat VD. Low-throughput technology (qRT-PCR/WB/immunohistochemical technology) detects oxidative stress-mediated inflammation and apoptosis-related signaling pathway molecules. The molecular docking results showed that 64474-51-7, cycloartenol, ferulic acid, formononetin, kaempferol, liquiritigenin, senkyunone, wallichilide, xanthinin, and other molecules can directly interact with NF-κB p65, BAX, BCL-2, and CASP3. CONCLUSION: The active compounds of MBHD interact with multiple targets and multiple pathways in a synergistic manner, and have important therapeutic effects on VD mainly by balancing oxidative stress/anti-inflammatory and antiapoptotic, enhancing metabolism, and enhancing the immune system.

Bushenhuoxue improves cognitive function and activates brain-derived neurotrophic factor-mediated signaling in a rat model of vascular dementia.

OBJECTIVE: To explore the protective mechanisms of the Traditional Chinese Medicine Bushenhuoxue (BSHX) in a rat model of vascular dementia (VD). METHODS: A rat model of VD was developed using bilateral common carotid artery occlusion (BCCAO). Rats were administered BSHX (10.14 or 5.07 g/kg), nimodipine (11.06 mg/kg; positive control), or saline (control) by gavage daily for 30 d post-surgery. Learning and memory abilities were assessed using the Morris water maze. Morphological changes in the hippocampus were observed using light microscopy (hematoxylin and eosin staining) and transmission electron microscopy (TEM). The mRNA and protein expression levels of brain-derived neurotrophic factor (BDNF), tyrosine receptor kinase B (TrkB), phosphatidyl inositol 3-kinase (PI3K), serine/threonine kinase (AKT), and cAMP response element binding protein (CREB) were measured by real-time polymerase chain reaction (RT-PCR) and Western blot, respectively. RESULTS: Compared with the sham group, rats with BCCAO exhibited impaired learning and memory abilities (Morris water maze) and showed abnormalities in neuronal morphology (light microscopy) and ultrastructure (TEM) in the hippocampus. They also had decreased mRNA and protein expressions of BDNF, TrkB, PI3K, AKT, and CREB in hippocampal tissue (all P < 0.05). In rats with BCCAO, administration of BSHX attenuated deficits in learning and memory, improved the morphology and ultrastructure of hippocampal neurons, and enhanced mRNA and protein expression levels of BDNF, TrkB, PI3K, AKT, and CREB (all P < 0.05). CONCLUSION: BSHX may protect hippocampal neurons and improve learning and memory abilities, at least in part via the activation of BDNF/TrkB/PI3K/AKT/CREB signaling.

Rhizoma Coptidis for Alzheimer's Disease and Vascular Dementia: A Literature Review.

BACKGROUND: Alzheimer's disease (AD) and vascular dementia (VaD) are major types of dementia, both of which cause heavy economic burdens for families and society. However, no currently available medicines can control dementia progression. Rhizoma coptidis, a Chinese herbal medicine, has been used for >2000 years and is now gaining attention as a potential treatment for AD and VaD. METHODS: We reviewed the mechanisms of the active ingredients of Rhizoma coptidis and Rhizoma coptidis-containing Chinese herbal compounds in the treatment of AD and VaD. We focused on studies on ameliorating the risk factors and the pathological changes of these diseases. RESULTS: The Rhizoma coptidis active ingredients include berberine, palmatine, coptisine, epiberberine, jatrorrhizine and protopine. The most widely studied ingredient is berberine, which has extensive therapeutic effects on the risk factors and pathogenesis of dementia. It can control blood glucose and lipid levels, regulate blood pressure, ameliorate atherosclerosis, inhibit cholinesterase activity, Aß generation, and tau hyperphosphorylation, decrease neuroinflammation and oxidative stress and alleviate cognitive impairment. Other ingredients (such as jatrorrhizine, coptisine, epiberberine and palmatine) also regulate blood lipids and blood pressure; however, there are relatively few studies on them. Rhizoma coptidis-containing Chinese herbal compounds like Huanglian-Jie-Du-Tang, Huanglian Wendan Decoction, Banxia Xiexin Decoction and Huannao Yicong Formula have anti-inflammatory and antioxidant stress activities, regulate insulin signaling, inhibit γ-secretase activity, neuronal apoptosis, tau hyperphosphorylation, and Aß deposition, and promote neural stem cell differentiation, thereby improving cognitive function. CONCLUSION: The "One-Molecule, One-Target" paradigm has suffered heavy setbacks, but a "multitarget- directed ligands" strategy may be viable. Rhizoma coptidis active ingredients and Rhizoma coptidiscontaining Chinese herbal compounds have multi-aspect therapeutic effects on AD and VaD.

In search of multimodal brain alterations in Alzheimer's and Binswanger's disease.

Structural and functional brain abnormalities have been widely identified in dementia, but with variable replicability and significant overlap. Alzheimer's disease (AD) and Binswanger's disease (BD) share similar symptoms and common brain changes that can confound diagnosis. In this study, we aimed to investigate correlated structural and functional brain changes in AD and BD by combining resting-state functional magnetic resonance imaging (fMRI) and diffusion MRI. A group independent component analysis was first performed on the fMRI data to extract 49 intrinsic connectivity networks (ICNs). Then we conducted a multi-set canonical correlation analysis on three features, functional network connectivity (FNC) between ICNs, fractional anisotropy (FA) and mean diffusivity (MD). Two inter-correlated components show significant group differences. The first component demonstrates distinct brain changes between AD and BD. AD shows increased cerebellar FNC but decreased thalamic and hippocampal FNC. Such FNC alterations are linked to the decreased corpus callosum FA. AD also has increased MD in the frontal and temporal cortex, but BD shows opposite alterations. The second component demonstrates specific brain changes in BD. Increased FNC is mainly between default mode and sensory regions, while decreased FNC is mainly within the default mode domain and related to auditory regions. The FNC changes are associated with FA changes in posterior/middle cingulum cortex and visual cortex and increased MD in thalamus and hippocampus. Our findings provide evidence of linked functional and structural deficits in dementia and suggest that AD and BD have both common and distinct changes in white matter integrity and functional connectivity.

Herbal Medicine for Vascular Dementia: An Overview of Systematic Reviews.

INTRODUCTION: Vascular dementia (VaD), a severe neurologic condition related to aging of the cerebrovascular structure, has been treated with herbal medications and products. In this overview of systematic reviews (SRs) on the effects of herbal medications, we aimed to summarize the current clinical evidence on the benefits of herbal drugs and to propose an evidence map outlining their effects on VaD. METHODS: SRs assessing their effects on cognitive function or performance and the associated safety, published until December 2018, were located from PubMed, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, China National Knowledge Infrastructure, and Oriental Medicine Advanced Searching Integrated System. A Measurement Tool to Assess systematic Reviews 2 was used to assess their overall confidence. A bubble plot was proposed to present the depth and width of the current status of the evidence supporting the use of individual herbal drugs. RESULTS: Ten SRs (4 on individual herbal medications and 6 on various herbal drugs) were included. The overall evidence on herbal medicines suggests that they are effective in improving cognitive function and performance. Individual herbal medications including FuFangHaiShe, NaoXinTong, YinDanXing- NaoTong, NaoMaiTai, ShenFuTang, and TongXinLuo showed favourable effects when assessed via a minimal mental state examination score but have limited evidence supporting their effectiveness due to the scarcity of randomized controlled trials. Concerning safety, most SRs did not outline the estimated risk ratio of adverse events. CONCLUSION: Herbal medications might have benefits for VaD patients but they need to be evaluated further.

Wuzang Wenyang Huayu decoction regulates differentially expressed transcripts in the rats' hippocampus after cerebral hypoperfusion.

The modified Wenyang Huayu decoction has been widely used to treat vascular dementia in China for thousands of years. We have previously proved that a modified version, Wuzang Wenyang Huayu decoction has the potential to be a more effective clinical treatment that can attenuate cerebral ischaemic injury. However, the global transcript profile and signalling conduction pathways regulated by this recipe remains unclear. This study established a two-vessel occlusion rat model by bilateral common carotid artery occlusion. Two groups of rats were intragastrically treated Wuzang Wenyang Huayu 2.5 g/kg vs or Piracetam 0.15 g/kg for 2 weeks. Learning and memory abilities were measured with Morris water maze. Neuronal plasticity was observed by HE staining. Differentially expressed transcripts of rat hippocampus were analysed by transcriptomics with Illumina HiSeq2500 platform. Results showed that Wuzang Wenyang Huayu decoction significantly alleviated learning, memory deficits, coordination dysfunction and prevented hippocampus cellular injury; Results further revealed the increased gene expression in KEGG metabolic pathways (MT-ND2. MT-ND3, MT-ND4, MT-ND4L, MT-ND5 and MT-ATP8) and genes involved in signal transduction, carcinogenesis, immune system, endocrine system, nervous system etc (Results further revealed differential expression of genes involved in various systems, including MT-ND2) Our discovery is likely to provide new insights to molecular mechanisms of Wuzang Wenyang Huayu regarding hippocampal transcripts in a murine vascular dementia model.

Discovery of Potent, Selective, and Orally Bioavailable Inhibitors against Phosphodiesterase-9, a Novel Target for the Treatment of Vascular Dementia.

To identify phosphodiesterase-9 (PDE9) as a novel target for the treatment of vascular dementia (VaD), a series of pyrazolopyrimidinone analogues were discovered based on a hit 1. Hit-to-lead optimization resulted in a potent inhibitor 2 with excellent selectivity and physicochemical properties to enable in vivo studies. Oral administration of 2 (5.0 mg/kg) caused notable therapeutic effects in the VaD mouse model, providing a promising lead or chemical probe for investigating the biological functions of PDE9 inhibition.

N-homocysteinylation of tau and MAP1 is increased in autopsy specimens of Alzheimer's disease and vascular dementia.

The pathomechanisms that associate a deficit in folate and/or vitamin B12 and the subsequent hyperhomocysteinemia with pathological brain ageing are unclear. We investigated the homocysteinylation of microtubule-associated proteins (MAPs) in brains of patients with Alzheimer's disease or vascular dementia, and in rats depleted in folate and vitamin B12, Cd320 KO mice with selective B12 brain deficiency and H19-7 neuroprogenitors lacking folate. Compared with controls, N-homocysteinylated tau and MAP1 were increased and accumulated in protein aggregates and tangles in the cortex, hippocampus and cerebellum of patients and animals. N-homocysteinylation dissociated tau and MAPs from ß-tubulin, and MS analysis showed that it targets lysine residues critical for their binding to ß-tubulin. N-homocysteinylation increased in rats exposed to vitamin B12 and folate deficit during gestation and lactation and remained significantly higher when they became 450 days-old, despite returning to normal diet at weaning, compared with controls. It was correlated with plasma homocysteine (Hcy) and brain expression of methionine tRNAsynthetase (MARS), the enzyme required for the synthesis of Hcy-thiolactone, the substrate of N-homocysteinylation. Experimental inactivation of MARS prevented the N-homocysteinylation of tau and MAP1, and the dissociation of tau and MAP1 from ß-tubulin and PSD95 in cultured neuroprogenitors. In conclusion, increased N-homocysteinylation of tau and MAP1 is a mechanism of brain ageing that depends on Hcy concentration and expression of MARS enzyme. Its irreversibility and cumulative occurrence throughout life may explain why B12 and folate supplementation of the elderly has limited effects, if any, to prevent pathological brain ageing and cognitive decline. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Effect of medicated thread moxibustion on apoptosis of hippocampal neurons in rat models of chronic cerebral ischemic vascular dementia.

To investigate the effect of medicated thread moxibustion onapoptosis in hippocampal neuronsin a rat model of chronic cerebral ischemic vascular dementia. A total of 40 male Wistar rats were randomly divided into normal group and sham-operated group (7 rats each), and rat model of chronic cerebral ischemic vascular dementia (14 rats). The model group rats were treated with medicated thread moxibustion two weeks after surgery, once a day, with one day break every six days, (24 times in all)and an observation period of 4 weeks. At the end of therapy, H&E staining was used to monitor changes in the neurons in CA1 area of the rat hippocampus. Changes in related indexes such as Bax, Bc1-2 and C-fos of neuron apoptosis in hippocampus CA1 area were determined by immunohistochemistry, while protein expression was semi-quantitatively assayed using imaging analysis technique. There was significant hippocampal neuronal necrosis six weeks after model establishment, but the necrosis was milder in rats in the medicated thread moxibustion group. Bax and C-fos were positively expressed and significantly higher in the hippocampus of chronic cerebral ischemic vascular dementia rats (model group) than in the medicated thread moxibustion group after treatment (p <0.01). The expression of Bcl-2 was increased in the medicated thread group after treatment, and was higher in the model group, but comparable to that in the sham-operated group (p=0.975>0.05). Medicated thread moxibustion alleviates hippocampal neuronal necrosis, inhibits neuron apoptosis in hippocampus CA1 area, protects nerves, and maintains relative equilibrium inBax/Bcl-2 through down-regulation of C-fos and Bax and up-regulation of Bcl-2. Thus, cell apoptosis-related pathway may be one of its mechanisms of action.

Harpagoside Rescues the Memory Impairments in Chronic Cerebral Hypoperfusion Rats by Inhibiting PTEN Activity.

Vascular dementia (VaD) is the second most common dementia worldwide. Unlike Alzheimer's disease, VaD does not yet have effective therapeutic drugs. Harpagoside is the most important component extracted from Harpagophytum procumbens, a traditional Chinese medicine that has been widely used. The neuroprotective effects of harpagoside have been studied in Aß- and MPTP-induced neurotoxicity. However, whether harpagoside is protective against VaD is not clear. In this study, with the use of chronic cerebral hypoperfusion rats, a well-known VaD model, we demonstrated that chronic administration (two months) of harpagoside was able to restore both the spatial learning/memory and fear memory impairments. Importantly, the protective effects of harpagoside were not due to alterations in the physiological conditions, metabolic parameters, or locomotor abilities of the rats. Meanwhile, we found that harpagoside suppressed the overactivation of PTEN induced by CCH by enhancing PTEN phosphorylation. Furthermore, harpagoside elevated the activity of Akt and inhibited the activity of GSK-3ß, downstream effectors of PTEN. Overall, our study suggested that harpagoside treatment might be a potential therapeutic drug targeting the cognitive impairments of VaD.

Anti-oxidative and Anti-apoptotic Effects of Acupuncture: Role of Thioredoxin-1 in the Hippocampus of Vascular Dementia Rats.

Emerging evidence suggests that acupuncture treatment has anti-oxidative effects that affect cognitive impairment in vascular dementia (VD) rats. In the present study, we aimed to investigate whether thioredoxin-1 (Trx-1)/thioredoxin reductase-1 (TrxR-1) was involved in the beneficial effects of acupuncture. After 2-weeks of acupuncture treatment, Morris water maze (MWM), dihydroethidium (DHE) staining, Nissl staining and TdT-mediated dUTP nick end labeling (TUNEL) staining were used to assess the effects of acupuncture on cognitive function and hippocampal neuronal injury in two-vessel occlusion (2VO) model. The protein and mRNA levels of Trx-1 and TrxR-1, the activity of TrxR-1 as well as the phosphorylation of the apoptosis signal-regulating kinase 1 (ASK1)-c-Jun N-terminal kinase (JNK)/p38 pathway were measured by Western blot, real-time PCR analysis, TrxR-1 activity analysis and immunofluorescence (IF) staining respectively. We found that there were oxidative and apoptotic injury in the CA1 area, accompanied with the decreased expressions of Trx-1 and TrxR-1 in the hippocampus. Acupuncture ameliorated cognitive deficits caused by cerebral ischemic injury and inhibited oxidative stress and neuronal apoptotic injury in the hippocampus. Acupuncture also up-regulated the expressions of Trx-1 and TrxR-1, increased the activity of TrxR-1, accompanied with inhibiting the activation of the ASK1-JNK/p38 pathway. However, the effects of acupuncture on improving cognitive function, inhibiting oxidative stress and neuron apoptotic damage were blocked by Trx-1siRNA. In conclusion, these findings indicated that acupuncture treatment improved VD though anti-oxidative and anti-apoptotic mechanisms which involved the up-regulations of Trx-1/TrxR-1 and inhibitions of ASK1-JNK/p38 pathway.

Ling-Yang-Gou-Teng-decoction prevents vascular dementia through inhibiting oxidative stress induced neurovascular coupling dysfunction.

ETHNOPHARMACOLOGICAL RELEVANCE: Vascular dementia (VaD) is the common cognitive disorder derived mainly from lacunar stroke (LS). The oxidative stress induced neurovascular coupling (NVC) dysfunction involves in the pathogenesis of VaD. Currently, there is no specific drug for VaD. Ling-Yang-Gou-Teng -Decoction (LG), a well-known traditional Chinese formula, has been used for preventing VaD in clinic. AIM OF THE STUDY: In this study, we aimed to investigate the underlying mechanism of LG on VaD in rats. MATERIALS AND METHOD: VaD was replicated with autologous micro-thrombi against the background of hypercholesterolemia induced with high fatty diet. PTX (68.90 mg/kg/day), LG with three dosages (2.58, 8.14, 25.80 g/kg/day) was orally administrated to VaD rats, respectively. The NVC sensitivity was defined as the ratio of the microcirculative cerebral blood velocity (CBV) to the electroencephalograph (EEG) before and after penicillin stimulation. Behavioral performance, pathological changes of brain and oxidation related molecules were detected to assess the effects of LG on VaD. RESULTS: LG exhibited beneficial effects on the VaD, which was demonstrated as improved exploratory, learning and memory abilities, relieved vascular or neural pathological changes in cerebral cortex or hippocampus. LG maintained NVC sensitivity, which was confirmed as significantly increased ΔCBV and the elevated ratio of ΔCBV/ΔqEEG. The underlying mechanisms of LG was associated with antioxidant effects, which was confirmed as significantly decreased nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) expression, and increased superoxide dismutase 3 (SOD3) expression. LG also reduced iNOS, increased nNOS and eNOS expression to restore NO bioavailability. CONCLUSIONS: The results suggested that LG prevented VaD may associate with inhibiting oxidative stress, protecting NO bioavailability, and then maintaining NVC sensitivity.

Acupuncture inhibits TXNIP-associated oxidative stress and inflammation to attenuate cognitive impairment in vascular dementia rats.

AIMS: Oxidative stress and inflammation have been implicated in the pathogenesis of vascular dementia (VD). Thioredoxin-interacting protein (TXNIP) plays a vital role in oxidative stress and NOD-like receptor protein 3 (NLRP3) inflammasome activation. There is evidence that acupuncture has an antioxidative and neuroprotective effect in VD. In this study, we investigated whether acupuncture can attenuate cognitive impairment via inhibiting TXNIP-associated oxidative stress and inflammation in VD rats. METHODS: Both common carotid arteries were occluded (2-vessel occlusion [2VO]) in rats to model VD. The neuroprotective effect of acupuncture was assessed by the Morris water maze and Nissl staining. Oxidative stress was assessed by detecting levels of reactive oxygen species, DNA oxidation, and antioxidase. Western blot, real-time PCR, and immunofluorescence were used to detect the expression of TXNIP, NLRP3, caspase-1, and IL-1ß. A TXNIP siRNA intraventricular injection was applied to investigate whether acupuncture mimicked the effect of TXNIP inhibitor. RESULTS: Our findings demonstrated that VD rats treated with acupuncture had reduced hippocampal neuronal loss and oxidative stress. The upregulation of TXNIP, NLRP3, caspase-1, and IL-1ß induced by 2VO was also reversed by acupuncture. Furthermore, TXNIP siRNA had a similar effect as acupuncture on cognition, hippocampal neurons, and ROS production in VD rats. CONCLUSION: In conclusion, our study suggests that the neuroprotective effects of acupuncture in VD are mediated through reducing expression of TXNIP-associated oxidative stress and inflammation.

Ligustrazine suppresses neuron apoptosis via the Bax/Bcl-2 and caspase-3 pathway in PC12 cells and in rats with vascular dementia.

The aim of this study was to examine the comprehensive neuroprotective mechanism of ligustrazine, which is extracted from Ligusticum Chuanxiong Hort., against vascular dementia (VD) in rats and apoptosis in oxygen and glucose deprivation (OGD) PC12 cells. Rats were subjected to bilateral common carotid artery occlusion (BCCAO) surgery and administered ligustrazine intragastrically for 6 weeks. At the end of the experiments, the hippocampal biomarkers brain-derived neurotrophic factor (BDNF), monocyte chemotactic protein 1 (MCP-1), and homocysteine (Hcy) were examined. In experiments in vitro, OGD PC12 cells were treated with ligustrazine for 0.5, 1, 3, 6, 12, or 24 h. The cell-released biomarkers BDNF, MCP-1, and Hcy were examined. Microscopy, acridine orange-ethidium bromide (AO/EB) staining, and flow cytometry assays were performed to investigate apoptosis. Cleaved caspase-3, Bcl-2 associated X protein (Bax), and B cell lymphoma 2 (Bcl-2) expression was examined using Western blot assays. The results showed that biomarkers, including MCP-1 and Hcy, were significantly increased in both the in vivo and in vitro models, while the BDNF level was significantly decreased compared with the sham or vehicle models. Microscopy, AO/EB staining, and flow cytometry analysis showed that severe cell damage occurred in OGD PC12 cells, and apoptosis played a major role in this environment. Further Western blot studies showed that the apoptosis-related Bax/Bcl-2 protein ratio and cleaved caspase-3 were significantly increased in the experiment. However, ligustrazine profoundly suppressed the imbalance of these biomarkers, reduced cell damage, decreased the Bax/Bcl-2, and downregulated cleaved caspase-3. Pro- and anti-apoptotic biomarkers of multiple pathways including BDNF, MCP-1, and Hcy played a joint role in triggering the activation of the mitochondria-related Bax/Bcl-2 and caspase-3 apoptosis pathway in VD. Ligustrazine attenuated VD by comprehensively regulating BDNF, MCP-1, and Hcy and inactivating the Bax/Bcl-2 and caspase-3 apoptosis pathway. Our data provide novel insight into ligustrazine, which is a promising neuroprotective agent for VD disease treatment strategies. © IUBMB Life, 70(1):60-70, 2018.

Paeoniflorin improves regional cerebral blood flow and suppresses inflammatory factors in the hippocampus of rats with vascular dementia.

OBJECTIVE: To explore the delayed neuroprotection induced by paeoniflorin (PF), the principal component of Paeoniae radix prescribed in Chinese medicine, and its underlying mechanisms in rats subjected to vascular dementia (VD). METHODS: A rat model of VD was induced by bilateral common carotid arteries occlusion (BCCAO). Low-dose or high-dose PF (20 or 40 mg/kg once per day) was administrated for 28 days after VD. The behavioral analysis of rat was measured by water morris. Regional cerebral blood volume (rCBV), regional cerebral blood flflow (rCBF) and mean transit time (MTT) were measured in the bilateral hippocampus by perfusion-weighted imaging (PWI). The levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were measured by commercially available enzyme-linked immunosorbent assay kits. Protein levels were evaluated by western blot analysis. mRNA levels were evaluated by real time-polymerase chain reaction. Western blotting was used to estimate p65 translocation. RESULTS: The behavioral analysis showed that PF could decrease the escape latency time (P<0.05), and increase the residence time of the original platform quadrant and the across platform frequency in water maze in VD rats (P<0.05). Likewise, PF remarkably promoted the rCBV (P<0.05), rCBF and decreased per minute MTT (P<0.05) in hippocampus of VD rats. Furthermore, PF decreased the release of IL-1ß, IL-6 and TNF-α as well as inhibited the mRNA expression of IL-1ß, IL-6 and TNF-α in the hippocampus of VD rats (P<0.05 or P<0.01). PF also could decrease the protein expressions of inducible nitric oxide synthase and cyclooxygenase-2 in the hippocampus of VD rats (P<0.05 or P<0.01). In addition, PF signifificantly inhibited the nuclear factor κB (NF-κB) pathway in the hippocampus of VD rats. CONCLUSIONS: PF signifificantly attenuates cognitive impairment, improves hippocampus perfusion and inhibits inflflammatory response in VD rats. In addition, the anti-inflflammatory effects of PF might be due to inhibiting the NF-κB pathway. PF may be a potential clinical application in improving VD.

Neuroprotective and memory enhancing effects of auraptene in a rat model of vascular dementia: Experimental study and histopathological evaluation.

Vascular dementia and Alzheimer disease are most common type of dementia. These diseases have been associated with cognitive decline and affected personal behavioral activities. Moreover, the pattern of cerebral blood flow in mild cognitive disorder has appeared as a predictive indication for the development into Alzheimer's disease. Permanent, bilateral occlusion of the common carotid arteries (2VO) is a standard animal model to study vascular dementia and chronic cerebral hypoperfusion. In present study neuroprotective and memory enhancing effects of auraptene (AUR), a citrus coumarin, were studied in 2VO rats. Different doses (25, 8 & 4mg/kg) of AUR were administered orally. The spatial memory performance was tested with Morris water maze after 2VO induction. Biochemical experiments and histopathological evaluations were also applied to investigate the neuroprotective effect of AUR in brain tissue. In comparison with 2VO group, AUR could significantly decrease the scape latency time in treated rats. Also AUR increased the percentage of time spent and traveled pathway in target quadrant on final trial test day. All behavioral results were confirmed by biochemical and histopathological data. Biochemical data indicated that AUR could decrease malondialdehyde (MDA), as lipid peroxidation indicator, and increase glutathione (GSH) content in cortex and hippocampus tissues. Histopathological data showed that AUR could protect cerebrocortical and hippocampus neurons against ischemia. This study demonstrated the memory enhancing effect and neuroprotective activity of AUR after induction of brain ischemia in a rat model of vascular dementia.

Chronic treatment with resveratrol, a natural polyphenol found in grapes, alleviates oxidative stress and apoptotic cell death in ovariectomized female rats subjected to chronic cerebral hypoperfusion.

OBJECTIVES: Resveratrol appears to have neuroprotective potential in various animal models of brain disorders including cerebral ischemia and neurodegenerative diseases. Chronic cerebral hypoperfusion is a well-known pathological condition contributing to the neurodegenerative diseases such as vascular dementia. Purpose of the present study is to evaluate the possible therapeutic potential of resveratrol in a model of vascular dementia of ovariectomized female rats. Assessment of the potential was based on the determination of brain oxidative status, caspase-3 level, glial fibrillary acidic protein (GFAP), and neuronal damage on hippocampus and cerebral cortex. METHODS: For creating the model of chronic cerebral hypoperfusion, ovariectomized female Wistar rats were subjected to the modified two vessel occlusion method, with the right common carotid artery being occluded first and the left one a week later. RESULTS: At the 15th day following the ligation, neuronal damage was accompanied by the increased immunoreactivities of both GFAP and caspase-3, and significant neurodegeneration was evident in the hippocampus and cortex, all of which were significantly alleviated with resveratrol treatment (10 mg/kg). Biochemical analysis revealed that the resveratrol treatment decreased lipid peroxidation and restored reduced glutathione level as well. DISCUSSION: The collected data of the present study suggest that the administration of resveratrol may provide a remarkable therapeutic benefit for vascular dementia, which is most likely related to the prevention of both apoptotic cell death and oxidative stress. We believe that therapeutic efficacy of resveratrol deserves to be tested for potential clinical application in postmenopausal elderly women suffering from vascular dementia.

Acupuncture ameliorates cognitive impairment and hippocampus neuronal loss in experimental vascular dementia through Nrf2-mediated antioxidant response.

Emerging evidence suggests acupuncture could exert neuroprotection in the vascular dementia via anti-oxidative effects. However, the involvement of Nrf2, a master regulator of antioxidant defense, in acupuncture-induced neuroprotection in vascular dementia remains undetermined. The goal of our study was to investigate the contribution of Nrf2 in acupuncture and its effects on vascular dementia. Morris water maze and Nissl staining were used to assess the effect of acupuncture on cognitive function and hippocampal neurodegeneration in experimental vascular dementia. The distribution of Nrf2 in neurons in hippocampus, the protein expression of Nrf2 in both cytosol and nucleus, and the protein and mRNA levels of its downstream target genes NQO1 and HO-1 were detected by double immunofluorescent staining, Western blotting and realtime PCR analysis respectively. Cognitive function and microglia activation were measured in both wild-type and Nrf2 gene knockout mice after acupuncture treatment. We found that acupuncture could remarkably reverse the cognitive deficits, neuron cell loss, reactive oxygen species production, and decreased cerebral blood flow. It was notable that acupuncture enhanced nuclear translocation of Nrf2 in neurons and up-regulate the protein and mRNA levels of Nrf2 and its target genes HO-1 and NQO1. Moreover, acupuncture could significantly down-regulated the over-activation of microglia after common carotid artery occlusion surgery. However, the reversed cognitive deficits, neuron cell loss and microglia activation by acupuncture were abolished in Nrf2 gene knockout mice. In conclusion, these findings provide evidence that the neuroprotection of acupuncture in models of vascular dementia was via the Nrf2 activation and Nrf2-dependent microglia activation.

Acupuncture attenuates cognitive deficits and increases pyramidal neuron number in hippocampal CA1 area of vascular dementia rats.

BACKGROUND: Decreased cognition is recognized as one of the most severe and consistent behavioral impairments in dementia. Experimental studies have reported that acupuncture may improve cognitive deficits, relieve vascular dementia (VD) symptoms, and increase cerebral perfusion and electrical activity. METHODS: Multi-infarction dementia was modeled in rats with 3% microemboli saline suspension. Two weeks after acupuncture at Zusanli (ST36), all rats were subjected to a hidden platform trial to test their 3-day spatial memory using the Morris water maze test. To estimate the numbers of pyramidal neuron, astrocytes, and synaptic boutons in hippocampal CA1 area, we adopted an unbiased stereology method to accurately sample and measure the size of cells. RESULTS: We found that acupuncture at ST36 significantly decreased the escape latency of VD rats. In addition, acupuncture significantly increased the pyramidal neuron number in hippocampal CA1 area (P < 0.05) and tended to decrease the number of astrocytes (P = 0.063). However, there was no significant change in the synaptic bouton number of hippocampal CA1 area in any of the groups (P > 0.05). CONCLUSIONS: These findings suggest that acupuncture may improve cognitive deficits and increase pyramidal neuron number of hippocampal CA1 area in VD rats.