Novel Flavonol Alkaloids in Green Tea: Synthesis, Detection, and Anti-Alzheimer's Disease Effect in a Transgenic Caenorhabditis elegans CL4176 Model.

Novel N-ethy-2-pyrrolidinone-substituted flavonols, myricetin alkaloids A-C (1-3), quercetin alkaloids A-C (4a, 4b, and 5), and kaempferol alkaloids A and B (6 and 7), were prepared from thermal reaction products of myricetin, quercetin, kaempferol─l-theanine, respectively. We used HPLC-ESI-HRMS/MS to detect 1-7 in 14 cultivars of green tea and found that they were all present in "Shuchazao," "Longjing 43", "Fudingdabai", and "Zhongcha 108" green teas. The structures of 1-4 and 6 were determined by extensive 1D and 2D NMR spectroscopies. These flavonol alkaloids along with their skeletal flavonols were assessed for anti-Alzheimer's disease effect based on molecular docking, acetylcholinesterase inhibition, and the transgenic Caenorhabditis elegans CL4176 model. Compound 7 strongly binds to the protein amyloid ß (Aß1-42) through hydrogen bonds (BE: -9.5 kcal/mol, Ki: 114.3 nM). Compound 3 (100 µM) is the strongest one in significantly extending the mean lifespan (13.4 ± 0.5 d, 43.0% promotion), delaying the Aß1-42-induced paralysis (PT50: 40.7 ± 1.9 h, 17.1% promotion), enhancing the locomotion (140.0% promotion at 48 h), and alleviating glutamic acid (Glu)-induced neurotoxicity (153.5% promotion at 48 h) of CL4176 worms (p < 0.0001).

Kaempferia parviflora Extracts Protect Neural Stem Cells from Amyloid Peptide-Mediated Inflammation in Co-Culture Model with Microglia.

The existence of neuroinflammation and oxidative stress surrounding amyloid beta (Aß) plaques, a hallmark of Alzheimer's disease (AD), has been demonstrated and may result in the activation of neuronal death and inhibition of neurogenesis. Therefore, dysregulation of neuroinflammation and oxidative stress is one possible therapeutic target for AD. Kaempferia parviflora Wall. ex Baker (KP), a member of the Zingiberaceae family, possesses health-promoting benefits including anti-oxidative stress and anti-inflammation in vitro and in vivo with a high level of safety; however, the role of KP in suppressing Aß-mediated neuroinflammation and neuronal differentiation has not yet been investigated. The neuroprotective effects of KP extract against Aß42 have been examined in both monoculture and co-culture systems of mouse neuroectodermal (NE-4C) stem cells and BV-2 microglia cells. Our results showed that fractions of KP extract containing 5,7-dimethoxyflavone, 5,7,4'-trimethoxyflavone, and 3,5,7,3',4'-pentamethoxyflavone protected neural stem cells (both undifferentiated and differentiated) and microglia activation from Aß42-induced neuroinflammation and oxidative stress in both monoculture and co-culture system of microglia and neuronal stem cells. Interestingly, KP extracts also prevented Aß42-suppressed neurogenesis, possibly due to the contained methoxyflavone derivatives. Our data indicated the promising role of KP in treating AD through the suppression of neuroinflammation and oxidative stress induced by Aß peptides.

Effects of common plastic products heat exposure on cognition: Mediated by gut microbiota.

Considering plastic exposure patterns in modern society, the effects of exposure to leachate from boiled-water treated plastic products on cognitive function was probed in mice through changes in gut microbiota diversity. In this study, Institute for Cancer Research (ICR) mice were used to establish drinking water exposure models of three popular kinds of plastic products, including non-woven tea bags, food-grade plastic bags and disposable paper cups. 16S rRNA was used to detect changes in the gut microbiota of mice. Behavioral, histopathology, biochemistry, and molecular biology experiments were used to evaluate cognitive function in mice. Our results showed that the diversity and composition of gut microbiota changed at genus level compared to control group. Nonwoven tea bags-treated mice were proved an increase in Lachnospiraceae and a decreased in Muribaculaceae in gut. Alistipes was increased under the intervention of food grade plastic bags. Muribaculaceae decreased and Clostridium increased in disposable paper cups group. The new object recognition index of mice in the non-woven tea bag and disposable paper cup groups decreased, and amyloid ß-protein (Aß) and tau phosphorylation (P-tau) protein deposition. Cell damage and neuroinflammation were observed in the three intervention groups. Totally speaking, oral exposure to leachate from boiled-water treated plastic results in cognitive decline and neuroinflammation in mammals, which is likely related to MGBA and changes in gut microbiota.

Naringin Protects against Tau Hyperphosphorylation in Aß 25-35-Injured PC12 Cells through Modulation of ER, PI3K/AKT, and GSK-3ß Signaling Pathways.

Alzheimer's disease (AD) is the most common form of dementia and a significant social and economic burden. Estrogens can exert neuroprotective effects and may contribute to the prevention, attenuation, or even delay in the onset of AD; however, long-term estrogen therapy is associated with harmful side effects. Thus, estrogen alternatives are of interest for countering AD. Naringin, a phytoestrogen, is a key active ingredient in the traditional Chinese medicine Drynaria. Naringin is known to protect against nerve injury induced by amyloid beta-protein (Aß) 25-35, but the underlying mechanisms of this protection are unclear. To investigate the mechanisms of naringin neuroprotection, we observed the protective effect on Aß 25-35-injured C57BL/6J mice's learning and memory ability and hippocampal neurons. Then, an Aß 25-35 injury model was established with adrenal phaeochromocytoma (PC12) cells. We examined the effect of naringin treatment on Aß 25-35-injured PC12 cells and its relationship with estrogen receptor (ER), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT), and glycogen synthase kinase (GSK)-3ß signaling pathways. Estradiol (E2) was used as a positive control for neuroprotection. Naringin treatment resulted in improved learning and memory ability, the morphology of hippocampal neurons, increased cell viability, and reduced apoptosis. We next examined the expression of ERß, p-AKT (Ser473, Thr308), AKT, p-GSK-3ß (Ser9), GSK-3ß, p-Tau (Thr231, Ser396), and Tau in PC12 cells treated with Aß 25-35 and either naringin or E2, with and without inhibitors of the ER, PI3K/AKT, and GSK-3ß pathways. Our results demonstrated that naringin inhibits Aß 25-35-induced Tau hyperphosphorylation by modulating the ER, PI3K/AKT, and GSK-3ß signaling pathways. Furthermore, the neuroprotective effects of naringin were comparable to those of E2 in all treatment groups. Thus, our results have furthered our understanding of naringin's neuroprotective mechanisms and indicate that naringin may comprise a viable alternative to estrogen therapy.

A Combination of Caffeine Supplementation and Enriched Environment in an Alzheimer's Disease Mouse Model.

A variety of factors has been associated with healthy brain aging, and epidemiological studies suggest that physical activity and nutritional supplements such as caffeine may reduce the risk of developing dementia and, in particular, Alzheimer's disease (AD) in later life. Caffeine is known to act as a cognitive enhancer but has been also shown to positively affect exercise performance in endurance activities. We have previously observed that chronic oral caffeine supplementation and a treatment paradigm encompassing physical and cognitive stimulation by enriched environment (EE) housing can improve learning and memory performance and ameliorate hippocampal neuron loss in the Tg4-42 mouse model of AD. Here, we investigated whether these effects were synergistic. To that end, previous findings on individual treatments were complemented with unpublished, additional data and analyzed in depth by ANOVA followed by Bonferroni multiple comparison post tests. We further evaluated whether plasma neurofilament light chain levels reflect neuropathological and behavioral changes observed in the experimental groups. While a treatment combining physical activity and caffeine supplementation significantly improved learning and memory function compared to standard-housed vehicle-treated Tg4-42 in tasks such as the Morris water maze, no major additive effect outperforming the effects of the single interventions was observed.

Effects of Melissa officinalis Extract Containing Rosmarinic Acid on Cognition in Older Adults Without Dementia: A Randomized Controlled Trial.

BACKGROUND: Previous in vitro and in vivo studies on Alzheimer's disease (AD) models have reported that rosmarinic acid (RA) can inhibit the formation of amyloid-ß fibrils as well as the oligomerization and deposition of amyloid-ß protein. Melissa officinalis (M. officinalis) extract containing 500 mg of RA is tolerable and safe in healthy individuals and patients with mild AD dementia. OBJECTIVE: This randomized placebo-controlled double-blind trial aimed to assess the effects of M. officinalis extract on cognition in older adults without dementia. METHODS: This study included individuals who were diagnosed with subjective or mild cognitive impairment (n = 323). The trial involved M. officinalis extract supplementation (500 mg of RA per day) period of 96 weeks followed by a washout period of 24 weeks. The primary endpoint was the Alzheimer's Disease Assessment Scale-cognitive subscale score, and the secondary endpoints were other cognitive measure results as well as safety and tolerability. RESULTS: There were no significant differences in cognitive measures between the placebo and M. officinalis groups from baseline to 96 weeks. However, based on the analysis of Clinical Dementia Rating Sum of Boxes scores in participants without hypertension, the score was found to be increased by 0.006 and decreased by 0.085 in the M. officinalis and placebo groups, respectively; this difference was statistically significant (p = 0.036). Furthermore, there were no differences in vital signs, physical and neurological measures, or hippocampal volume between the two groups. CONCLUSION: These results indicate that M. officinalis extract may help prevent cognitive decline in older adults without hypertension.

Aerobic Training with Naringin Supplementation Improved Spatial Cognition via H2S Signaling Pathway in Alzheimer's Disease Model Rats.

OBJECTIVES: This study examined the effects of one-month naringin administration and exercise training on cognitive impairment and H2S signaling pathway in an Amyloid ß (Aß)-injected rat. METHODS: Rats were divided into four groups: control group; rats underwent Aß microinjection surgery, exercise group; rats underwent Aß microinjection surgery and trained by treadmill for four weeks, naringin group; rats underwent Aß microinjection surgery, and rats orally administrated 80 mg.kg-1 naringin for four weeks, naringin+exercise group; rats underwent Aß microinjection surgery and were trained by treadmill for four weeks, and also, rats orally administrated 80 mg.kg-1 naringin for four weeks. After one month of treatment, spatial learning and memory were measured, and then hippocampi were sampled. S-adenosylmethionine (SAM), cystathionine-ß-synthase (CBS), hydrogen sulfide (H2S) levels, and neuronal death were detected in the hippocampi of rats. RESULTS: Naringin and exercise improved spatial learning (latency time, P < .001) and memory (P < .001) in the Morris Water Maze test in Aß-injected rats compared with the control group. SAM (P < .01), CBS (P < .001), and H2S (P < .01) levels are increased in the naringin+exercise group compared with the control group. CONCLUSION: The result of this study supports the effect of exercise and/or naringin to improve cognitive dysfunction and cell death through the production of H2S.

Vitamin D3 supplementation ameliorates cognitive impairment and alters neurodegenerative and inflammatory markers in scopolamine induced rat model.

A multifaceted approach can be effective for the treatment of dementia including the most common form, Alzheimer's disease (AD). However, currently, it involves only symptomatic treatment with cholinergic drugs. Beneficial effects of high Vitamin D3 levels or its intake in the prevention and treatment of cognitive disorders have been reported. Thus, the present study examined the preventive effect of Vitamin D3 (Calcitriol) supplementation on cognitive impairment and evaluated its impact on the accumulation or degradation of Aß plaques. A single intraperitoneal injection of scopolamine was used to induce cognitive impairment in rats. Treatment of Vitamin D3 was provided for 21 days after the injection. Various behavioral parameters like learning, spatial memory and exploratory behavior, biochemical alterations in the brain homogenate and histology of the hippocampus were investigated. Our results indicated that scopolamine-induced rats depicted cognitive deficits with high Aß levels and hyperphosphorylated tau proteins in the brain tissue, while Vitamin D supplementation could significantly improve the cognitive status and lower these protein levels. These results were supported by the histopathological and immunohistochemical staining of the hippocampal brain region. Furthermore, mechanistic analysis depicted that Vitamin D supplementation improved the Aß protein clearance by increasing the neprilysin levels. It also reduced the accumulation of Aß plaques by lowering neuroinflammation as well as oxidative stress. The present findings indicate that Vitamin D3 supplementation can ameliorate cognitive deficits and thereby delay AD progression by increasing Aß plaque degradation, reducing inflammation and oxidative stress.

Blueberry Anthocyanins Extract Attenuates Acrylamide-Induced Oxidative Stress and Neuroinflammation in Rats.

Acrylamide (AA) is a widespread environmental and dietary-derived neurotoxin, which can induce oxidative stress and associated inflammation in the brain. Anthocyanins widely occur as natural antioxidant and anti-inflammatory phytochemicals. Herein, the protective effects of blueberry anthocyanins extract (BAE) against AA-induced neurotoxicity were investigated in rats. The rats were pretreated with BAE (175 mg/kg body weight/day) by oral gavage for the first 7 days, followed by the co-administration of BAE and AA (35 mg/kg body weight/day) by oral gavage for the next 12 days. Results showed that BAE significantly decreased the malondialdehyde (MDA) production, and increased glutathione (GSH) and antioxidant enzyme levels; and it also suppressed microglial activation, astrocytic reaction, and pro-inflammatory cytokine expressions. Furthermore, BAE elevated the extracellular signal-related kinase (ERK)/cAMP response elements binding protein (CREB)/brain-derived neurotrophic factor (BDNF) pathway, and relieved the accumulation of amyloid beta (Aß) 1-42 and 1-40 after AA exposure. Consequently, AA-induced neuronal necrosis and downregulation of synaptosomal-associated protein 25 (SNAP-25) were attenuated by BAE in the hippocampus and cerebral cortex. In conclusion, BAE can exert a protective function on neurons and synapses against AA-induced oxidative stress and neuroinflammation.

Quercitrin improved cognitive impairment through inhibiting inflammation induced by microglia in Alzheimer's disease mice.

OBJECTIVE: Diets rich in quercitrin show a neuroprotective effect, but the mechanism is not very clear at present. The objective of this study is to explore the effect and mechanism of quercitrin in the treatment of alzheimer's disease (AD). METHODS: 5XFAD transgenic mice were fed with a diet supplemented with quercitrin for three consecutive months. Behavioral experiments were conducted to assess the cognitive ability, luminex liquid chip technology was used to assess the production of proinflammatory cytokines and immunohistochemistry was used to elucidate the activation of microglia. RESULTS: Quercitrin increased the frequency in exploring new objects, shortened the escape latency and increased the frequency crossing the platform in AD model mice. Quercitrin inhibited the activation and proliferation of microglia, inhibited the secretion of inflammatory cytokines and chemokines and reduced the accumulation of amyloid-ß plaques in AD model mice. CONCLUSION: Quercitrin improved mice cognitive impairment through alleviating the intensity of inflammatory response and is a promising medicinal plant extract in the treatment of AD.

Acupuncture Effect Assessment in APP/PS1 Transgenic Mice: On Regulating Learning-Memory Abilities, Gut Microbiota, and Microbial Metabolites.

Alzheimer's disease (AD) is a brain illness that affects learning and memory capacities over time. In recent investigations, acupuncture has been shown to be an effective alternative treatment for AD. We investigated the effect of acupuncture on learning and memory abilities using a water maze in APP/PS1 transgenic mice. The amounts of Aß and tau protein in mice's hippocampal tissue were determined using Western blot. The levels of IL-1ß, IL-10, LPS and TNF-α in mice's serum were measured using ELISA. The variations of gut microbiota in mice's feces were determined using the 16SrDNA technique, and the metabolites were examined using a untargeted metabolomics methodology. The results showed that acupuncture treatment improved mice's learning and memory abilities substantially. Acupuncture therapy regulated the Aß and tau protein concentration as well as the levels of IL-10 and LPS. Acupuncture treatment influenced the mouse microbiota and metabolites and had been linked to six biochemical pathways. This study adds to our understanding of the effect of acupuncture on AD and opens the door to further research into the alterations of intestinal bacteria in the presence of AD.

Gut microbiota modulation in Alzheimer's disease: Focus on lipid metabolism.

BACKGROUND & AIMS: Alzheimer's disease (AD) and age-related dementias represent a major and increasing global health challenge. Unhealthy diet and lifestyle can unbalance the intestinal microbiota composition and, consequently energy metabolism, contributing to AD pathogenesis. Impairment of cerebral cholesterol metabolism occurs in both aging and AD, and lipid-lowering agents have been associated to a lower risk of neurodegenerative diseases, but the link between blood lipid profile and AD remains a matter of debate. Recently, probiotics have emerged as a promising and safe strategy to manipulate gut microbiota composition and increase the host health status through a multi-level mechanism that is currently under investigation. Specifically, oral supplementation with a multi-strain probiotic formulation (SLAB51) reduced amyloid beta aggregates and brain damages in a triple transgenic mouse model of AD (3xTg-AD). Treated mice showed improved cognitive functions in response to an enrichment of gut anti-inflammatory metabolites, increased plasma concentrations of neuroprotective gut hormones, and ameliorated glucose uptake and metabolism. METHODS: This work focuses on the evaluation of the effects of SLAB51 chronic administration on lipid metabolism in 3xTg-AD mice and the respective wild-type counterpart. On this purpose, 8 weeks old mice were orally administered with SLAB51 for 4 and 12 months to analyze the plasma lipid profile (using lipidomic analyses and enzymatic colorimetric assays), along with the cerebral and hepatic expression levels of key regulators of cholesterol metabolism (through Western blotting and ELISA). RESULTS: Upon probiotics administration, cholesterol biosynthesis was inhibited in AD mice with a process involving sterol regulatory element binding protein 1c and liver X receptors mediated pathways. Decreased plasma and brain concentration of 27-hydroxycholesterol and increased brain expression of cholesterol 24S-hydroxylase indicated that alternative pathways of bile acid synthesis are influenced. The plasmatic increase of arachidonic acid in treated AD mice reflects dynamic interactions among several actors of a complex inflammatory response, in which polyunsaturated fatty acids can compete each other and simultaneously co-operate in the resolution of inflammation. CONCLUSIONS: These evidence, together with the hypocholesterolemic effects, the ameliorated fatty acids profile and the decreased omega 6/omega 3 ratio successfully demonstrated that microbiota modulation through probiotics can positively change lipid composition in AD mice, with arachidonic acid representing one important hub metabolite in the interactions among probiotic-induced lipid profile changes, insulin sensitivity, and inflammation.

Optimal Formula of Angelica sinensis Ameliorates Memory Deficits in ß-amyloid Protein-induced Alzheimer's Disease Rat Model.

OBJECTIVE: Angelica (A.) sinensis is used as a traditional medical herb for the treatment of neurodegeneration, aging, and inflammation in Asia. A. sinensis optimal formula (AOF) is the best combination in A. sinensis that has been screened to rescue the cognitive ability in ß-amyloid peptide (Aß25-35)-treated Alzheimer's disease (AD) rats. The objective of this study was to investigate the effect of AOF on the learning and memory of AD rats as well as to explore the underlying mechanisms. METHODS: Male Wistar rats were infused with Aß25-35 for AD model induction or saline (negative control). Five groups of AD rats were fed on AOF at 20, 40, or 80 mL/kg every day, donepezil at 0.9 mg/kg every day (positive control), or an equal volume of water (AD model) intragastrically once a day for 4 weeks, while the negative control rats were fed on water. The Morris water maze test was used to evaluate the cognitive function of the rats. The Aß accumulation, cholinergic levels, and antioxidative ability were detected by ELISA. Additionally, the candidate mechanism was determined by gene sequencing and quantitative real-time polymerase chain reaction. RESULTS: The results showed that AOF administration significantly ameliorated Aß25-35-induced memory impairment. AOF decreased the levels of amyloid-ß precursor protein and Aß in the hippocampus, rescued the cholinergic levels, increased the activity of superoxide dismutase, and decreased the malondialdehyde level. In addition, AOF inhibited the expression of IL1b, Mpo, and Prkcg in the hippocampus. CONCLUSION: These experimental findings illustrate that AOF prevents the decrease in cognitive function and Aß deposits in Aß25-35-treated rats via modulating neuroinflammation and oxidative stress, thus highlighting a potential therapeutic avenue to promote the co-administration of formulas that act on different nodes to maximize beneficial effects and minimize negative side effects.

Molecular Insights to the Wnt Signaling During Alzheimer's Disorder: a Potential Target for Therapeutic Interventions.

In the adult brain, Wnt signaling is crucial for neurogenesis, and it also regulates neuronal development, neuronal maturation, neuronal differential, and proliferation. Impaired Wnt signaling pathways are associated with enhanced levels of amyloid-ß, reduced ß-catenin levels, and increased expression of GSK-3ß enzyme, suggesting its direct association with the pathogenesis of Alzheimer's disorder (AD). These findings are consolidated by reports where activation of Wnt signaling by genetic factors and pharmacological intervention has improved the cognitive functions in animals and restored neurogenesis in the adult brain. Various natural and synthetic molecules have been identified that modulate Wnt signaling in the adult brain and promote neurogenesis and alleviate behavioral dysfunction. These molecules include lithium, valproic acid, ethosuximide, selenomethionine, curcumin, andrographolide, xanthoceraside, huperzine A, pyridostigmine, ginkgolide-B, ricinine, cannabidiol, and resveratrol. These molecules are associated with the DKK1 and GSK-3ß inhibition and ß-catenin stabilization along with their effects on neurogenesis, neuronal proliferation, and differentiation in the hippocampus through modulation of Wnt signaling and thereby could prove beneficial in the management of AD pathogenesis. Although modulation of the Wnt signaling seems to suggest to be promising in the management of AD, unfortunately, most of the literature available for the association of Wnt signaling and AD pathogenesis is either from preclinical studies or post-mortem brain. Therefore, it will be interesting to understand the role of Wnt signaling in AD patients, and a rigorous investigation could provide us with a better understanding of AD pathogenesis and the identification of novel targets for therapeutic interventions.

Effect of Dietary Pyrroloquinoline Quinone Disodium Salt on Cognitive Function in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study.

BACKGROUND: Cognitive dysfunctions are increasing alarmingly around the world, and researchers are exploring preventive measures for improving brain performance. Pyrroloquinoline quinone (PQQ), a naturally occurring coenzyme in foods, exhibits potent antioxidant activity, and improves diverse functions which include mitochondrial activation, growth, repair, protection of nerve cells by increased expression of nerve growth factor (NGF) and NGF receptors; and suppression of fibril formation and aggregation of amyloid ß. OBJECTIVE: This randomized, double-blind, placebo-controlled, parallel-group clinical investigation (RCT) evaluated the efficacy and safety of PQQ disodium salt powder (mnemoPQQ®) for improved cognitive function after 12 weeks of supplementation in healthy Japanese male and female (age 40 to <80 Y). METHODS: 64 healthy subjects were randomly assigned to receive either mnemoPQQ® (PQQ disodium salt: 21.5 mg/day) or a placebo over a period of 12 weeks. The efficacy of mnemoPQQ® on cognitive performance (memory, attention, judgment, and cognitive flexibility) was examined using Cognitrax as the primary outcome (primary endpoint), and forgetfulness questionnaire (DECO: Deterioration Cognitive Observee) and Mini-Mental State Examination-Japanese (MMSE-J) as the secondary outcome (secondary endpoint). RESULTS: A total of 58 subjects (placebo = 31; Age = 70.91 ± 3.06 Y; mnemoPQQ® group = 27; Age = 72.10 ± 3.77 Y) completed the study over a period of 12 weeks of supplementation. Significant improvements were observed on the Cognitrax's cognitive function domain score on "composite memory", "verbal memory", "reaction time", "complex attention", "cognitive flexibility", "executive function", and "motor speed" in the mnemoPQQ® group as compared to the placebo group. The DECO and the MMSE-J scores were also significantly improved in the mnemoPQQ® group. No adverse events were observed. CONCLUSIONS: Study demonstrates that supplementation of PQQ disodium salt is useful in improving memory, attention, judgment, and cognitive function, in middle-aged to elderly population, who feel they have become more forgetful because of aging.

Dietary uptake of Salvia macilenta extract improves Nrf2 antioxidant signaling pathway and diminishes inflammation and apoptosis in amyloid beta-induced rats.

BACKGROUND: Studies showed the protective role of Salvia in traditional medicine against neurodegenerative diseases. Salvia macilenta is one of the potent antioxidant herbs among Salvia species against oxidative stress. In the current study, the effect of oral administration of S. macilenta in the antioxidant, anti-inflammatory activities of Aß-injected male albino Wistar rats was determined. METHODS: Rats were received S. macilenta (50 mg/kg/day) orally, for ten successive days and then some of them received Aß (10 ng/µl) in their hippocampus (CA1 region). Proteins involved in antioxidant defense system and inflammatory signaling pathways in the hippocampus and prefrontal cortex were evaluated using Western blotting technique. To study apoptosis, Western blotting technique and histological staining were used. Catalase activity, glutathione peroxidase (GSH) and nitric oxide levels were measured. RESULTS: Results demonstrated that S. macilenta increased Nrf2 protein level and decreased TNFα and IL-6 protein level in Aß-injected rats compared to the Aß-injected group in the hippocampus and prefrontal cortex. Histological analysis showed pretreatment with S. macilenta decreased apoptosis levels in the hippocampus and prefrontal cortex, about 41 and 42%, compared to Aß-injected rats, respectively. This study showed that catalase activity was changed in the S. macilenta + Aß group compared to the Aß-injected rats. Also, GSH level was increased in the S. macilenta + Aß group compared to the Aß-injected rat. CONCLUSION: Orally treatment of S. macilenta extract in Aß-injected rats could ameliorate protective pathways and, so, it can be one of the proposed dietary supplements for the prevention of Alzheimer's disease and dementia.

Preventive effect of Ninjin-yoei-to, a Kampo medicine, on amyloid ß1-42-induced neurodegeneration via intracellular Zn2+ toxicity in the dentate gyrus.

Ninjin-yoei-to (NYT), a Kampo medicine, has ameliorative effects on cognitive dysfunction via enhancing cholinergic neuron activity. To explore an efficacy of NYT administration for prevention and cure of Alzheimer's disease, here we examined the effect of NYT on amyloid ß1-42 (Aß1-42)-induced neurodegeneration in the dentate gyrus. A diet containing 3% NYT was administered to mice for 2 weeks and human Aß1-42 was intracerebroventricularly injected. Neurodegeneration in the dentate granule cell layer of the hippocampus, which was determined 2 weeks after the injection, was rescued by administration of the diet for 4 weeks. Aß staining (uptake) was not modified in the dentate granule cell layer by pre-administration of the diet for 2 weeks, while Aß1-42-induced increase in intracellular Zn2+ was reduced, suggesting that pre-administration of NYT prior to Aß injection is effective for reducing Aß1-42-induced Zn2+ toxicity in the dentate gyrus. As a matter of fact, Aß1-42-induced neurodegeneration in the dentate gyrus was rescued by pre-administration of NYT. Interestingly, the level of metallothioneins, intracellular Zn2+-binding proteins, which can capture Zn2+ from Zn-Aß1-42 complexes, was elevated in the dentate granule cell layer by pre-administration of NYT. The present study suggests that pre-administration of NYT prevents Aß1-42-mediated neurodegeneration in the dentate gyurs by induced synthesis of metallothioneins, which reduces intracellular Zn2+ toxicity induced by Aß1-42.

Lindera glauca Blume ameliorates amyloid-ß1-42-induced memory impairment in mice with neuroprotection and activation of the CREB-BDNF pathway.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder presenting cognitive decline accompanied by deposits of amyloid-ß (Aß) and tau hyperphosphorylation. Without current treatment to AD, many studies suggested diverse approaches, one of which was herbal medicine and its active compounds. Very few studies have examined the effect of Lindera glauca Blume (L. glauca) in models of degenerative disease despite the attention that it received as a novel potential treatment source. We examined the efficacy of L. glauca in a mouse model of AD, which was induced by intrahippocampal injection of Aß1-42. METHODS: Mice were intrahippocampally infused with Aß1-42 and were orally administered ethanolic extract of L.glauca before and after infusion for 21 days. Y-maze test and Morris water maze was conducted to assess memory impairment. Immunohistochemistry and western blot analysis were performed to assess the effect of L. glauca administration on pathological changes in mice. RESULTS: L. glauca exhibited beneficial effects in spatial and reference learning as shown in increased time spent in the target quadrant in Morris water maze and increased spontaneous alternation in Y-maze. At the same time, decline of Aß burden and phosphorylated tau were observed in the hippocampus of L. glauca-treated mouse under intrahippocampal injection of Aß1-42. The results corresponded with amelioration of the decreased neuronal marker, neuronal-specific nuclear protein (NeuN) and attenuation of the increased reactive astrocyte marker, glial fibrillary acidic protein (GFAP) levels in hippocampus. Additionally, 21-day treatment with L. glauca inhibited downregulation of phosphorylated cAMP response element-binding protein (p-CREB) and brain-derived neurotrophic factor (BDNF) levels. CONCLUSION: L. glauca improves behavioral deficits induced by Aß1-42 and inhibits both Aß- and tau-related pathological changes, stimulating neuroprotection mediated by CREB activation. L. glauca can be suggested as a new candidate for treatment of AD.

"Olfactory three-needle" acupuncture enhances synaptic function in Aß1-42-induced Alzheimer's disease via activating PI3K/AKT/GSK-3ß signaling pathway.

Synaptic dysfunction and neuronal loss are related to cognitive impairment of Alzheimer's disease. Recent evidence indicates that regulating the phosphatidylinositol 3-Kinase (PI3K)/AKT/GSK-3ß pathway is a therapeutic strategy for improving synaptic plasticity in Alzheimer's disease. Here, we investigated "olfactory three-needle" effects on synaptic function and the PI3K/AKT/GSK-3ß signaling pathway in ß-amyloid1-42 (Aß1-42)-induced Alzheimer's disease rats. A three-needle olfactory bulb insertion for 28 days alleviated Aß1-42-induced Alzheimer's disease rats' cognitive impairment as assessed by performance in the Morris water maze test. Furthermore, the three-needle electrode inhibited neuro-apoptosis and neuro-inflammation. It significantly upregulated the protein expression of postsynaptic density protein 95, synaptophysin, and GAP43, indicating a protective effect on hippocampal synaptic plasticity. Additionally, the activation level of PI3K/AKT signaling and the phosphorylation inactivation of GSK-3ß were significantly enhanced by the "olfactory three-needle". Our findings suggested that the three-needle acupuncture is a potential alternative to improve synaptic plasticity and neuronal survival of Alzheimer's disease brain in rodents.

The Effect of TCM-Induced HAMP on Key Enzymes in the Hydrolysis of AD Model Cells.

Alzheimer's disease (AD) process is characterized classically by two hallmark pathologies: ß-amyloid (Aß) plaque deposition and neurofibrillary tangles of hyperphosphorylated tau. Aß peptides play an important role in AD, but despite much effort the molecular mechanisms of how Aß contributes to AD remain unclear. The present study evaluated the effects of the active components of Epimedium, Astragalus and Radix Puerariae induced HAMP on key enzymes in the hydrolysis of APP in HT22 cells. The active components of Epimedium, Astragalus and Radix Puerariae could effectively up-regulate the expression of HAMP, alleviate the iron overload in the brain tissues of mice, significantly improve the learning and memory ability of AD, down-regulate the expression of Aß and reduce the deposition of SP in an APPswe/PS1ΔE9 transgenic mouse model of AD. HAMP and Aß25-35 induced HT22 cells are used as AD cell models in this study to investigate the effect of the compound consisting of the effective components of Epimedium, Astragalus and Pueraria on the key enzymes in the hydrolysis of APP. After the administration of traditional Chinese medicine (TCM), the expression levels of ADAM10 and ADAM17 were increased while the expression level of BACE1 decreased. This indicates that TCM can promote the expression level of ADAM10 and ADAM17, inhibit the expression level of BACE1, thus further inhibiting the production of amyloid protein and reducing the production of Aß and SP. Compared with RNAi group, the expression level of ADAM10 and ADAM17 in Aß + RNAi group was decreased while the expression level of BACE1 increased. Compared with the Aß + RNAi group the expression level of ADAM10 and ADAM17 in the Aß + RNAi + TCM group was increased while the expression level of BACE1 was decreased. The present study indicated the effects of the active components of Epimedium, Astragalus and Radix Puerariae may alleviate AD by up-regulating the expression of HAMP, thus reducing brain iron overload, promoting the expression of ADAM10 and ADAM17, inhibiting the expression of BACE1, and reducing the deposition of Aß.