ABSTRACT
Microglia, the main immune macrophages in the central nervous system, can be highly involved in the occurrence and development of Alzheimer's disease(AD)through microglia polarization and receptor protein expression. Traditional Chinese Medicine has been demonstrated to have regulatory effects on MG. Many active components in Traditional Chinese herbs play important roles in decreasing β-amyloid peptide(Aβ)accumulation, inhibiting neuro-inflammation and regulating microglia polarization etc. In this study the role of microglia in the pathogenesis of AD and the mechanism by which Traditional Chinese Medicine regulating microglia are reviewed to provide a reference for the treatment of AD.
ABSTRACT
Objective To observe the effect of electroacupuncture at " Baihui"," Shenshu" and " Taixi" points on learning and memory,the expression of Aβ and insulin degrading enzyme(IDE) in the brain of SAMP8 mice.Methods Eight-month-old SAMR1 and SAMP8 mice were treated with electroacupuncture at " Baihui"," Shenshu" and "Taixi" points for eight consecutive weeks.The distribution and expression of Aβ and IDE in the brain prefrontal cortex of mouse were observed using immunohistochemistry and Western blot.Learning and memory function was assayed by Morris water maze(MWM).Results Compared with the normal control group,the brain prefrontal cortex of SAMP8 mice showed increased Aβ levels ((179.02± 15.11) ％),decreased IDE protein expression ((51.35 ± 14.94) ％).MWM showed the escape latency in SAMP8 mice was significantly longer than that in the control group (P＜0.05).Compared with the model group,Aβ levels in SAMP8 mice were markedly decreased in electroacupuncture group((119.72±9.21)％) and memantine-treated group ((116.84 ± 12.09) ％).IDE protein levels were increased by ((92.06 ± 8.05) ％) and ((83.84± 15.28) ％) after treatment with electroacupuncture and memantine relative to model group.MWM showed the escape latency was significantly shorter in SAMP8 mice treated with electroacupuncture and memantine than that in the model group(P＜0.05).Conclusion Electroacupuncture at " Baihui"," Shenshu" and "Taixi" points can inhibit Aβ levels,increase the expression of IDE and improve the learning and memory function of SAMP8 mice.
ABSTRACT
OBJECTIVE To observe the effect of baicalin on Aβ25-35 induced learning and memory deficits and changes in autophagy-related genes in mice so as to explore the related mechanisms of Alzheimer disease (AD) treatment . METHODS C57 mice were administered with 3μL Aβ25-35 3 mmol·L-1 by intracerebroventricular injection to establish an AD model. Baicalin was given by intracerebroventricular injection at the dose of 25, 50 and 100 mg · kg-1 for 15 d, respectively. The total distance and the central grid residence time were measured in the open-field test. The escape latency and the time to reach the platform were monitored in the Morris water maze trial. The autophagic vacuoles in the hippocampus of the mice were observed by transmission electron microscopy before the protein expressions of microtu?bule-associated protein 1 light chain 3 (LC3) and Beclin1 in brain tissue were analyzed by Western blot?ting assay. RESULTS Intracerebroventricular injection of Aβ25-35 could reduce the total distance from (3984±321)cm to (2790±306)cm and extend central grid residence time from (3.6±1.2)s to (8.8±2.9)s in the open-field test. The escape latency of water maze also increased from (22.0 ± 1.9)s to (38.8 ± 2.2)s. Autophagic vacuoles or late autophagic vacuoles and increased Beclin1 and LC3 and protein level were observed in the hippocampus after Aβ25-35 injection. Intraperitoneal injection of Baicalin 50 and 100 mg · kg-1 for fifteen consecutive days extended the total distance in open-field test to (3705 ± 337)cm and (3968 ± 448)cm, respectively, while the central grid residence time was reduced to (5.6 ± 1.8)s and (3.9±1.5)s, respectively. The total time taken to reach the platform in water maze test was reduced to (28.6± 1.9)s, (22.9 ± 1.7)s. Mitochondrial swelling, vacuolar membrane structure or autophagic vacuoles were visible in the hippocampus. LC3 and Beclin1 protein expression was significantly up-regulated(P<0.01). CONCLUSION Baicalin shows protective effect against Aβ25-35 induced learning and memory deficits, and this effect may be related to the activation of autophagy in the mouse hippocampus.
ABSTRACT
This study was designed to investigate the effect of gastrodin (GAS) against β-amyloid plaques in 5×FAD Alzheimer's disease (AD) transgenic mice, and utilize 117 cell model (over-expression of Aβ and β-secretase) to explore the underlying mechanism. 5×FAD mice model were randomly divided into three groups, including GAS-high dose group (GAS-H, 200 mg·kg-1·d-1), GAS-middle dose group (GAS-M, 100 mg·kg-1·d-1) and GAS-low dose group (GAS-L, 50 mg·kg-1·d-1). Meanwhile, the wild type mice were used in the control group. After being treated with GAS for three months, 5×FAD mice were evaluated by Morris water maze for the learning and memory ability and by ELISA for Aβ in the cerebral homogenate. Then, Aβplaques in the hippocampus and cortex of 5×FAD mice were observed and analyzed with immunohistochemical staining. The cell apoptosis rate and the cell viability were determined in vitro, after the cells were treated with different concentrations of GAS (10, 25, 50 and 100 μmol·L-1). Furthermore, Intracelluar/extracelluar Aβ were determined by ELISA. Effects of GAS on BACE (β-secretase site APP cleaving enzyme) mRNA and protein expression were analyzed in 117 cell models by Q-PCR and Western blotting. The results suggest that GAS is able to restore the learning and memory capacity of 5×FAD mice, and reduce Aβ in the cerebral homogenate and Aβ plaques in the brain. Compared with the untreated transgenic positive group, A β plaques were declined in hippocampus and cortex of GAS-H group by 93.28% and 88.88%, and A β was reduced in the cerebral homogenate by 55.74%. In vitro study suggests a dose-dependent effect of GAS in reducing Aβ in 117 cell models. When the cells were treated with 100 μmol·L-1 GAS, extracelluar Aβ and intracellular Aβ of 117 cells were reduced by 63.1% and 49.1%. BACE expression was largely suppressed in mRNA by 32.9% (P-1 GAS, the protein level was declined by 47.9% (Pβ production and accumulation by inhibiting β-secretase.
ABSTRACT
Aim To explore the effects and mecha-nisms of choro-oxime derivatives on spatial learning and memory impairment in Kunming mice and SD rats induced by scopolamine and Aβ1-42 , respectively. Methods 40 Kunming mice were randomly divided into 5 groups: control group, model group, donepezil treatment group, arimoclomol treatment group and TCO-2 treatment group. There were 8 mice in each group. Mice of control group were established by intra-peritoneal injection of saline, and mice of other groups were injected with scopolamine and caused memory im-pairment. Both control group and model group were treated with solvent by intraperitoneal administration;donepezil treatment group received donepezil by intra-gastric administration; arimoclomol treatment group and TCO-2 treatment group were given the correspond-ing drugs by abdominal injection, respectively. The solvent and drugs were given at the same time every morning for 8 days. Spatial learning and memory abili-ty were tested by Morris water maze from the fifth day of the drugs administration. 40 SD rats were divided into 5 groups the same as the dementia model men-tioned above. Mice of control group were established by intracerebroventricular injection of saline, and mice of other groups were injected with insoluble Aβ1-42 to be induced of memory impairment. Solvent and drugs were also delivered as mentioned above. Morris water maze was carried out from the fifth day of the drug de-livery. After that, acetyl cholinesterase activity of hip-pocampus was tested with acetyl cholinesterase reagent kit; the content of Aβ1-42 in hippocampus was meas-ured by ELISA assay kit;the expression of phosphoryl-ated tau proteins was detected by Western Blot. Re-sults In both two dementia models, choro-oxime de-rivatives could improve the spatial learning and memory ability, shorten the escape latency and increase the times of crossing the former platform. Choro-oxime de-rivatives could also inhibit the acetyl cholinesterase ac-tivity in animal brain, decrease the concentration of Aβ1-42 and the expression of phosphorylated tau pro-teins in the dementia rats’ hippocampus. Conclusions Spatial learning and memory deficits induced by sco-polamine and Aβ1-42 could be reversed by choro-oxime derivatives. It may be concerned with enhancement of the cholinergic system functions and reduction of the levels of Aβ1-42 and phosphorylated tau proteins in the brain.
ABSTRACT
Objective: To determine the effect of polygona-polysaccharose (PP) on learning and memory ability in rats with Alzheimer’s disease (AD). Methods: Forty ifve Sprague-Dawley rats were assigned into 3 groups. Rats in the sham-operated group were injected with normal saline. Rats in the Aβ group were injected with Aβ1-42. Rats in the PP group were injected with 16% PP solution for 45 days consecutively. hTe Morris water maze was used to investigate the ability of learning and memory in the rats. hTe effect of Aβ and PP on the hippocampus cells was observed by HE and Congo red staining of methanol. Results: Rats in the sham-operated group had no obvious morphological change; and morphology of rats in the PP group was basicaly normal. The layer of pyramidal cells in the Aβ group was decreased. hTe cells appeared sparse and irregular and became smaller. Karyopyknosis and vacuolardegeneration cells were also found. More positive staining materials aggradated in the Aβ group compared with the PP group by Congo red staining (P<0.05). Conclusion: Aβ infusion into the hippocampus results in the impairment of the neuronal degeneration in the rats, which shows similar characterizations of AD. PP can reduce the deposition of Aβ in the hippocampus.
ABSTRACT
This study was aimed to observe different forms of β-amyloid peptide (Aβ) and insulin degrading enzyme (IDE) in the hippocampus and cortex in order to further explore the role of Aβ and IDE on spleen yin deficiency di-abetes-associated cognitive decline (DACD), and the effect of Zi-Bu Pi-Y in method. The rats were randomly divided into five groups, which were the blank control (Cont) group, diabetes (DM) group, spleen yin deficiency (pi) group, spleen yin deficiency diabetes (piDM) group and Zi-Bu Pi-Y in recipe (ZBPYR) group. Soluble and insoluble Aβ in the hippocampus and cortex of rats were extracted by gradient centrifugation, and then measured by ELISA. The ex-pression of IDE was observed by western blot. The results showed that the content of soluble and insoluble Aβ1-42 in the hippocampus and cortex of the DM group and piDM group were higher than the Cont group. The soluble and in-soluble Aβ1-42 content in the hippocampus and cortex of the ZBPYR group were reduced compared with the DM group and the piDM group. The soluble Aβ1-40 in the cortex of the DM group, pi group and piDM group were in-creased compared with the Cont group (P < 0.05). The soluble Aβ1-40 content of the ZBPYR group was decreased compared with the DM group and the piDM group (P < 0.05). The expression of IDE protein was decreased in the hippocampus of the DM group and the piDM group compared with the Cont group (P< 0.05), and the IDE protein level in the hippocampus of the ZBPYR group was increased compared with the DM group and the piDM group (P<0.05). The expression of IDE protein in the cortex of the DM group, pi group and piDM group was lower than the Cont group (P< 0.05). The IDE protein level in the cortex of the ZBPYR group was reduced compared to the DM group (P< 0.05). It was concluded that the increased Aβ1-42 in brain may be a major pathological change of DACD and spleen yin deficiency DACD. The decreased IDE expression may be one of the reasons to induce increasing of Aβ1-42 level. The Zi-Bu Pi-Y in method may decrease the Aβ1-42 content by upregulating IDE protein expression.
ABSTRACT
Objective To study the effect of ratanasampil (RNSP) which is Traditional Tibetan Medicine on the levels of serum β-amyloid protein, interleukin and tumor necrosis factor alpha (TNF-α) in patients with mild to moderate Alzheimer's disease (AD). Methods One hundred AD patients were divided into two groups in randomized controlled study, including treatment group (RNSP 1 g/d) and control group (piracetam 2.4 g/d). The treatment lasted 12 weeks. The Mini Mental State Examination (MMSE), Alzheimer' s disease Assessment Scale-cognitive subscale (ADAS-cog) and Activity of Daily Living Scale (ADLs) were taken to evaluate the efficacy. Serum levels of amyloid peptides (Aβ40 and Aβ42 ) were measured by ELISA assay. The radioimmunologic assay was used to determine the serum levels of IL-1β, IL-2, IL-6, IL-8 and TNF-α. Results The scores of MMSE, ADAS-cog and ADL significantly improved at 12 weeks after RNSP treatment (P＜0.01, 0.01, 0.05, respectively), while had no significant changes in piracetam group (P＜0.05).The levels of TNF-α, IL-1β, IL-6 and Aβ42 were significantly lower in RNSP group than in Piracetam group (P＜0.01). There was a decrease trend of the Aβ42/Aβ40 ratio at 12 weeks after RNSP treatment (P＜0. 05, P＜0.01 ). The serum Aβ42 level had strong correlations with TNF-α, IL-1 β and IL-6. There were no significant differences in Aβ40 and IL-8 between RNSP group and piracetam group. No obvious drug side effect happened on the groups. Conclusions The reductions of serum TNF-α, IL-1β and IL-6 levels after RNSP treatment may lead to decrease of Aβ42 production in AD patients. RNSP may decrease the Aβ42/Aβ40 ratio and slow down the progress of AD. It may improve the learning and memory ability in treating patients with mild to moderate AD and is well tolerated and safe.