BACKGROUND/OBJECTIVES: Alzheimer's disease (AD) is characterized by deficits in memory and cognitive functions. The accumulation of amyloid beta peptide (Abeta) and oxidative stress in the brain are the most common causes of AD. MATERIALS/METHODS: Caffeic acid (CA) is an active phenolic compound that has a variety of pharmacological actions. We studied the protective abilities of CA in an Abeta25-35-injected AD mouse model. CA was administered at an oral dose of 10 or 50 mg/kg/day for 2 weeks. Behavioral tests including T-maze, object recognition, and Morris water maze were carried out to assess cognitive abilities. In addition, lipid peroxidation and nitric oxide (NO) production in the brain were measured to investigate the protective effect of CA in oxidative stress. RESULTS: In the T-maze and object recognition tests, novel route awareness and novel object recognition were improved by oral administration of CA compared with the Abeta25-35-injected control group. These results indicate that administration of CA improved spatial cognitive and memory functions. The Morris water maze test showed that memory function was enhanced by administration of CA. In addition, CA inhibited lipid peroxidation and NO formation in the liver, kidney, and brain compared with the Abeta25-35-injected control group. In particular, CA 50 mg/kg/day showed the stronger protective effect from cognitive impairment than CA 10 mg/kg/day. CONCLUSIONS: The present results suggest that CA improves Abeta25-35-induced memory deficits and cognitive impairment through inhibition of lipid peroxidation and NO production.
Administration, Oral ; Alzheimer Disease* ; Amyloid beta-Peptides ; Animals ; Brain ; Kidney ; Lipid Peroxidation ; Liver ; Memory ; Memory Disorders ; Mice ; Nitric Oxide ; Oxidative Stress ; Phenol ; Water

OBJECTIVETo study the effects of immunization with the fusion protein CAC (a product of prokaryotic expression of recombinant HBcAg and β-amyloid peptide fusion gene) against the toxicity induced by intrahippocampal injection of aggregated β-amyloid peptide (Aβ) in rats.

METHODSSD rats were immunized intraperitoneally with the fusion protein CAC, and the titer of anti-Aβ antibody was evaluated by ELISA. When the titers of the anti-Aβ antibody reached 1:3 000, aggregated Aβ was injected into the CA1 region of the rat hippocampus. Two weeks after Aβ injection, the rats underwent morris water maze test before sacrificed to prepare the brain slices with Congo red and haematoxylin staining.

RESULTSThe titer of anti-Aβ antibody reached 1:3 000 after 5 immunizations with the fusion protein. After Aβ injection, the saline-immunized rats showed a reduced cognitive behavior in the Morris water maze test compared to the CAC-immunized rats. In the saline-immunized rats, the neurons around the site of Aβ injection exhibited obvious cell damages with Aβ deposits and glial infiltration, whereas in CAC-immunized rats, Aβ deposits were significantly reduced or even absent.

CONCLUSIONImmunization with the fusion protein CAC can inhibit the toxicity induced by intrahippocampal aggregated Aβ injection.

Amyloid beta-Peptides ; administration & dosage ; biosynthesis ; genetics ; immunology ; Animals ; Antibodies ; blood ; Hepatitis B Core Antigens ; biosynthesis ; genetics ; Hippocampus ; metabolism ; Immunization ; Injections ; Male ; Peptide Fragments ; administration & dosage ; immunology ; Rats ; Rats, Sprague-Dawley ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

BACKGROUNDThe advent of brain stimulation techniques to treat movement disorders and psychiatric diseases has shown potential to decode the neural mechanism that underlies the cognitive process by modulating the interrupted circuit. Here, the present investigation aimed at evaluating the influence of deep brain stimulation of the anterior nucleus thalamus (ANT-DBS) on memory.

METHODSThirty-two rats were randomized into phosphate buffer saline (PBS) group (n = 8, rats received PBS injections without implantation of electrodes into the ANT), Alzheimer's dementia (AD) group (n = 8, rats received Aβ1-40 injections without implantation of electrodes into the ANT), ANT sham stimulation group (n = 8, rats received Aβ1-40 injections with implantation of electrodes into the ANT but without stimulation) and ANT stimulation group (n = 8, rats received Aβ1-40 injections with implantation of electrodes into the ANT and stimulation). A Morris maze test was used for determining the effect of electrical stimulation on cognitive function in rats. The data were assessed statistically with one-way analysis of variance (ANOVA) followed by Tukey's tests for multiple post hoc comparisons.

RESULTSThe data showed that in the training test, PBS group and AD group managed to learn the hidden-platform faster and faster while AD group needed a significantly longer time to reach the platform than PBS group (P < 0.05). Meanwhile, ANT stimulation group demonstrated a significantly shorter time to reach the platform (P < 0.05) compared to the AD group, while there was no significant difference between the ANT sham stimulation group and the AD group (P > 0.05). On the probe test, the AD group spent less time ((10.15 ± 2.34) seconds) in the target quadrant than the PBS group ((28.20 ± 2.75) seconds) (P < 0.05). And the times of platform-traversing of the AD group (3.35 ± 1.12) significantly decreased compared with the PBS group (8.69 ± 2.87) (P < 0.05). However, the times of platform-traversing and the time spent in the target quadrant of the ANT stimulation group significantly increased compared to the AD group (P < 0.05), while times of platform-traversing or the time spent in the target quadrant was not significantly different between the ANT sham stimulation group and the AD group (P > 0.05).

CONCLUSIONBilateral high-frequency stimulation of the ANT may be useful as a potential therapeutic modality for cognitive dysfunction in AD.

Amyloid beta-Peptides ; administration & dosage ; toxicity ; Animals ; Anterior Thalamic Nuclei ; drug effects ; Cognition ; drug effects ; Cognition Disorders ; chemically induced ; therapy ; Deep Brain Stimulation ; methods ; Hippocampus ; drug effects ; Male ; Peptide Fragments ; administration & dosage ; toxicity ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the changes of p38MAPK expression in a rat model of Alzheimer disease (AD).

METHODSSeventy-two adult SD rats were randomized equally into 4 groups, and a single-dose injection of Abeta25-35 (dementia group), normal saline (saline group), SB203580 (inhibitor group), or DMSO (inhibitor control group) was administered into the lateral cerebral ventricle. Y-maze tast was performed to evaluate the behavioral changes of the rats after the injections, and on days 4, 7 and 14 after the injection, p38MAPK expression in the hippocampal CA1 area was measured by means of immunohistochemistry.

RESULTSOn days 7 and 14 following Abeta25-35 injection, the training times, error number and total reaction time were significantly higher in dementia group than in saline group (P<0.05), but all these indices were significantly lowered in the inhibitor group as compared with the dementia group (P<0.05). Immunohistochemistry revealed obvious p38 expression in the dementia group 4 days after Abeta25-35 injection, which increased significantly with the passage of time (P<0.01). The gray scale in the inhibitor group was significantly higher than that in the dementia group (P<0.01).

CONCLUSIONp38MAPK activation in the hippocampal CA1 area is an event that persists during the entire course of Abeta25-35-induced AD in rats, and the inhibitor SB203580 prevents p38MAPK expression and improves the learning and memory abilities of the rats.

Alzheimer Disease ; chemically induced ; enzymology ; metabolism ; Amyloid beta-Peptides ; administration & dosage ; toxicity ; Animals ; Hippocampus ; drug effects ; enzymology ; Immunohistochemistry ; Male ; Maze Learning ; drug effects ; Peptide Fragments ; administration & dosage ; toxicity ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; p38 Mitogen-Activated Protein Kinases ; biosynthesis

Tongluo Xingnao effervescent tablet (TLXNET) is a patented prescription, which comes from modified Xionggui decoction and can improve cognitive function. However, its effect on the urine metabolites and anti-dementia mechanism in the dementia model rats induced by hippocampal injection with A&beta;25-35 remains unclear. The experiment focused on the changes in trajectory and inter-relationship among the urinary metabolite of rats in the blank group, A&beta;25-35 hippocampal injection dementia model group and the TLXNET intervention group, in order to determine theirs characteristic metabolic markers and explain the anti-dementia effect of TLX-NET base on the change of metabolic trajectory of these bio-markers. According to the experimental results, 5, 6-indolequinone, 4-hydroxyphenyl pyruvic acid (4-HPPA), cortisol and 3-thiosulfate lactic were preliminarily identified as the characteristic metabolic markers. They mainly participate in dopamine system, glucocorticoids and energy metabolic pathways. TLXNET can apparently downregulate the disturbances of metabolic trajectory of the four bio-markers. The experiment indicates that the dementia model induced by injecting A&beta;25-3 into hippocampus has its characteristic endogenous metabolic markers in urine, and ELXNET can ameliorate dementia by down-regulating the disturbances of metabolic trajectory.
Amyloid beta-Peptides ; metabolism ; toxicity ; Animals ; Biomarkers ; urine ; Dementia ; drug therapy ; urine ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Hippocampus ; drug effects ; metabolism ; Humans ; Male ; Metabolomics ; Peptide Fragments ; metabolism ; toxicity ; Rats ; Rats, Sprague-Dawley ; Tablets ; administration & dosage ; Urine ; chemistry

OBJECTIVETo investigate the expression of Redox factor-1(Ref-1) in rats with Alzheimer's disease (AD).

METHODSAD rat model was established by a single injection of beta-amyloid peptide (Abeta25-35) into the lateral cerebral ventricle of rats. Y-shape maze task was conducted to check the ethology. At 4th, 7th and 14th day after injection, Ref-1 expression in hippocampus CA1 area was detected by immunohistochemistry.

RESULTThe numbers of repeated learning and error and the total reaction time in AD group were significantly higher than those in control group at 7th and 14th day after injection of Abeta25-35 (P<0.05). At 4th day after injection of Abeta25-35, the Ref-1 expression was increased with time prolongation in AD group(P<0.01).

CONCLUSIONInjection of Abeta25-35 in lateral cerebral ventricle can decrease the learning and memory abilities of rats, and results also indicate that Ref-1 expression in hippocampus may be involved in the development of AD.

Alzheimer Disease ; chemically induced ; metabolism ; Amyloid beta-Peptides ; administration & dosage ; Animals ; DNA-(Apurinic or Apyrimidinic Site) Lyase ; metabolism ; Hippocampus ; drug effects ; metabolism ; Male ; Maze Learning ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley

To study the effect of Cu2+ and Zn2+ on amyloid-beta peptides (Abeta) aggregation, the morphology, size and cell toxicity of Abeta40 aggregates formed with the metal ions have been observed by the methods including ultraviolet spectroscopy, fluorescence spectroscopy and transmission electron microscopy. The results showed that Cu2+ and Zn2+ can accelerate Abeta40 aggregation, and both changed the morphology and size of Abeta40 aggregates. Zn2+ induced Abeta40 to form fibrous Abeta40 aggregates, while the amorphous and fibrous aggregates were produced by the interaction between Cu2+ and Abeta40. In addition, H2O2 was produced when Abeta40 reduced Cu2+. The relationship between metal ions and Abeta40 aggregates was analyzed, and the function of metal ions in Alzheimer's disease (AD) was illustrated in the research.
Amyloid beta-Peptides ; chemistry ; Cell Survival ; drug effects ; Copper ; administration & dosage ; chemistry ; toxicity ; Dose-Response Relationship, Drug ; HeLa Cells ; Humans ; Hydrogen Peroxide ; chemistry ; Ions ; chemistry ; Microscopy, Electron, Transmission ; Peptide Fragments ; chemistry ; Spectrometry, Fluorescence ; Spectrophotometry, Ultraviolet ; Zinc ; chemistry

Cranberry extract (CBE) rich in polyphenols are potent to delay paralysis induced by alleviating β-amyloid (Aβ) toxicity in C. elegans model of Alzheimer's disease (AD). In order to better apply CBE as an anti-AD agent efficiently, we sought to deterrmine whether preventive or therapeutic effect contributes more prominently toward CBE's anti-AD activity. As the level of Aβ toxicity and memory health are two major pathological parameters in AD, in the present study, we compared the effects of CBE on Aβ toxicity and memory health in the C. elegans AD model treated with preventive and therapeutic protocols. Our results revealed that CBE prominently showed the preventive efficacy, providing a basis for further investigation of these effects in mammals.
Alzheimer Disease ; drug therapy ; genetics ; metabolism ; psychology ; Amyloid beta-Peptides ; metabolism ; toxicity ; Animals ; Caenorhabditis elegans ; drug effects ; metabolism ; Dietary Supplements ; analysis ; Disease Models, Animal ; Female ; Fruit ; chemistry ; Humans ; Male ; Memory ; drug effects ; Plant Extracts ; administration & dosage ; Vaccinium macrocarpon ; chemistry

BACKGROUNDAlzheimer's disease (AD) is a neurodegenerative disorder and the leading cause of dementia in the elderly. The two hallmark lesions in AD brain are deposition of amyloid plaques and neurofibrillary tangles (NFTs). Hypercholesteremia is one of the risk factors of AD. But its role in the pathogenesis of AD is largely unknown. The aim of this study was to investigate the relationship between hypercholesteremia and tau phosphorylation or beta-amyloid (Abeta), and evaluate the effect of atorvastatin on the level of tau phosphorylation and Abeta in the brains of rats fed with high cholesterol diet.

METHODSSprague-Dawley (SD) rats were randomly divided into normal diet control group, high cholesterol diet group, and high cholesterol diet plus atorvastatin (Lipitor, 15 mg x kg(-1) x d(-1)) treated group. Blood from caudal vein was collected to measure total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and high-density lipoprotein (HDL) at the end of the 3rd and the 6th months by an enzymatic method. The animals were sacrificed 6 months later and brains were removed. All left brain hemispheres were fixed for immunohistochemistry. Hippocampus and cerebral cortex were separated from right hemispheres and homogenized separately. Tau phosphorylation and Abeta in the brain tissue were determined by Western blotting (using antibodies PHF-1 and Tau-1) and anti-Abeta40/anti-Abeta42, respectively.

RESULTSWe found that high cholesterol diet led to hypercholesteremia of rats as well as hyperphosphorylation of tau and increased Abeta level in the brains. Treatment of the high cholesterol diet fed rats with atorvastatin prevented the changes of both tau phosphorylation and Abeta level induced by high cholesterol diet.

CONCLUSIONSHypercholesteremia could induce tau hyperphosphorylation and Abeta production in rat brain. Atorvastatin could inhibit tau hyperphosphorylation and decrease Abeta generation. It may play a protective role in the patho-process of hypercholesteremia-induced neurodegeneration in the brain.

Administration, Oral ; Amyloid beta-Peptides ; metabolism ; Animals ; Antibodies, Monoclonal ; Atorvastatin Calcium ; Blotting, Western ; Brain ; drug effects ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Heptanoic Acids ; administration & dosage ; pharmacology ; therapeutic use ; Immunohistochemistry ; Male ; Phosphorylation ; drug effects ; Pyrroles ; administration & dosage ; pharmacology ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; tau Proteins ; metabolism

OBJECTIVETo observe the effect of total coptis alkaloids (TCA) on beta -amyloid peptide (A beta 25-35) induced learning and memory dysfunction in rats, and to explore its mechanism.

METHODSForty male Wistar rats were randomly divided into four groups: the control group, the model group, the TCA low dose (60 mg/kg) group and the TCA high dose (120 mg/kg) group, 10 in each. A beta 25-35 (5microl, 2 microg/microl) was injected into bilateral hippocampi of each rat to induce learning and memory dysfunction. TCA were administered through intragavage for consecutive 15 days. Morris Water Maze test was used to assess the impairment of learning and memory; concentration of malondialdehyde (MDA) in cerebral cortex was determined by thiobarbituric acid reactive substance to indicate the level of lipid peroxidation in brain tissues; activity of manganese-superoxide dismutase (Mn-SOD) in cerebral cortex was determined by xanthine-oxidase to indicate the activity of the enzyme; and NF- kappa B protein expression in cerebral cortex was measured by SP immunohistochemistry.

RESULTS(1) Morris Water Maze test showed that, during the 4 consecutive days of acquisition trials, the rats in the model group took longer latency and searching distance than those in the control group (P<0.01), which could be shortened by high dose TCA (P<0.05); during the spatial probe trial on the fifth day, the rats in the model group took shorter searching time and distance on the previous flat area than those in the control group (P<0.01), which could be prolonged after TCA treatment (for low dose group, P<0.05; for high dose group, P<0.01). (2) Analysis of cerebral cortical tissues showed that, compared with the control group, MDA level got significantly increased and Mn-SOD activity decreased in the model group (both P<0.01). After having been treated with TCA, the MDA level got significantly decreased (P<0.05 and P<0.01 respectively for low and high dose group), while relative increase of Mn-SOD activity only appeared in high dose group (P<0.05). (3) Immunohistochemistry analysis showed the protein expression of NF- kappa B got significantly increased after modeling, while high dose TCA can significantly inhibit it.

CONCLUSIONTCA could improve A beta 25-35 induced dysfunction of learning and memory in rats, and its protective mechanism is associated with its actions in decreasing MDA level, increasing Mn-SOD activity and inhibiting the expression of NF-kappa B in cerebral cortex.

Alkaloids ; administration & dosage ; pharmacology ; Amyloid beta-Peptides ; administration & dosage ; Animals ; Cerebral Cortex ; metabolism ; Coptis ; chemistry ; Dose-Response Relationship, Drug ; Hippocampus ; drug effects ; Injections ; Learning Disorders ; chemically induced ; psychology ; Male ; Malondialdehyde ; metabolism ; Maze Learning ; drug effects ; Memory ; drug effects ; Memory Disorders ; chemically induced ; psychology ; NF-kappa B ; metabolism ; Peptide Fragments ; administration & dosage ; Rats ; Rats, Wistar ; Reaction Time ; drug effects ; Superoxide Dismutase ; metabolism ; Swimming