Moscatilin Ameliorates Tau Phosphorylation and Cognitive Deficits in Alzheimer's Disease Models

GSK3: A potential target and pending issues for treatment of Alzheimer's disease

Glycogen synthase kinase-3 (GSK3), consisting of GSK3α and GSK3β subtypes, is a complex protein kinase that regulates numerous substrates. Research has observed increased GSK3 expression in the brains of Alzheimer's disease (AD) patients and models. AD is a neurodegenerative disorder with diverse pathogenesis and notable cognitive impairments, characterized by Aβ aggregation and excessive tau phosphorylation. This article provides an overview of GSK3's structure and regulation, extensively analyzing its relationship with AD factors. GSK3 overactivation disrupts neural growth, development, and function. It directly promotes tau phosphorylation, regulates amyloid precursor protein (APP) cleavage, leading to Aβ formation, and directly or indirectly triggers neuroinflammation and oxidative damage. We also summarize preclinical research highlighting the inhibition of GSK3 activity as a primary therapeutic approach for AD. Finally, pending issues like the lack of highly specific and affinity-driven GSK3 inhibitors, are raised and expected to be addressed in future research. In conclusion, GSK3 represents a target in AD treatment, filled with hope, challenges, opportunities, and obstacles.

Neuroprotective Effects of Davallia mariesii Roots and Its Active Constituents on Scopolamine-Induced Memory Impairment in In Vivo and In Vitro Studies

Beta-amyloid (Aβ) proteins, major contributors to Alzheimer's disease (AD), are overproduced and accumulate as oligomers and fibrils. These protein accumulations lead to significant changes in neuronal structure and function, ultimately resulting in the neuronal cell death observed in AD. Consequently, substances that can inhibit Aβ production and/or accumulation are of great interest for AD prevention and treatment. In the course of an ongoing search for natural products, the roots of Davallia mariesii T. Moore ex Baker were selected as a promising candidate with anti-amyloidogenic effects. The ethanol extract of D. mariesii roots, along with its active constituents, not only markedly reduced Aβ production by decreasing β-secretase expression in APP-CHO cells (Chinese hamster ovary cells which stably express amyloid precursor proteins), but also exhibited the ability to diminish Aβ aggregation while enhancing the disaggregation of Aβ aggregates, as determined through the Thioflavin T (Th T) assay. Furthermore, in an in vivo study, the extract of D. mariesii roots showed potential (a tendency) for mitigating scopolamine-induced memory impairment, as evidenced by results from the Morris water maze test and the passive avoidance test, which correlated with reduced Aβ deposition. Additionally, the levels of acetylcholine were significantly elevated, and acetylcholinesterase levels significantly decreased in the brains of mice (whole brains). The treatment with the extract of D. mariesii roots also led to upregulated brain-derived neurotrophic factor (BDNF) and phospho-cAMP response element-binding protein (p-CREB) in the hippocampal region. These findings suggest that the extract of D. mariesii roots, along with its active constituents, may offer neuroprotective effects against AD. Consequently, there is potential for the development of the extract of D. mariesii roots and its active constituents as effective therapeutic or preventative agents for AD.

Nature's Toolbox Against Tau Aggregation: An Updated Review of Current Research

Tau aggregation is a hallmark of several neurodegenerative disorders, such as Alzheimer's disease (AD), frontotemporal dementia, and progressive supranuclear palsy. Hyperphosphorylated tau is believed to contribute to the degeneration of neurons and the development of these complex diseases. Therefore, one potential treatment for these illnesses is to prevent or counteract tau aggregation. In recent years, interest has been increasing in developing nature-derived tau aggregation inhibitors as a potential treatment for neurodegenerative disorders. Researchers have become increasingly interested in natural compounds with multifunctional features, such as flavonoids, alkaloids, resveratrol, and curcumin, since these molecules can interact simultaneously with the various targets of AD. Recent studies have demonstrated that several natural compounds can inhibit tau aggregation and promote the disassembly of pre-formed tau aggregates. Nature-derived tau aggregation inhibitors hold promise as a potential treatment for neurodegenerative disorders. However, it is important to note that more research is needed to fully understand the mechanisms by which these compounds exert their effects and their safety and efficacy in preclinical and clinical studies. Nature-derived inhibitors of tau aggregation are a promising new direction in the research of neurodegenerative complexities. This review focuses on the natural products that have proven to be a rich supply for inhibitors in tau aggregation and their uses in neurodegenerative complexities, including AD.

Modern interpretation of the traditional application of Shihu - A comprehensive review on phytochemistry and pharmacology progress of Dendrobium officinale

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) "Shihu" has a long history of medicinal use in China from some species of Dendrobium. D. officinale is a major source of "Shihu" and is widely cultivated in south of China and listed separately as "Tiepi Shihu" by the Chinese Pharmacopoeia in now time. Traditionally, D. officinale has been widely used in daily health care and the treatment of diabetes and gastrointestinal diseases.

AIM OF THIS REVIEW

In order to better develop and utilize D. officinale, we conducted this systematic review of previous studies, showed clear structure of all isolates from D. officinale together with pharmacological progress, hoping to provide references for further research and utilization. In addition, specific display of the chemical components and the research progress of related activities can help to better understand the traditional records and modern pharmaceutical applications of the plant medicine.

MATERIALS AND METHODS

Information on phytochemistry and pharmacological studies of D. officinale was collected from various scientific databases including Web of Science, SciFinder, ACS, Springer, Scopus, PubMed, ScienceDirect, Google Scholar and CNKI.

RESULTS

More than 180 compounds isolated from D. officinale, including bibenzyls, phenols, phenylpropanoids, lignans, flavonoids and polysaccharides are listed in this review. Furthermore, modern pharmacological researches such as hypoglycemia, immune regulation, antioxidant, cardiovascular regulation and gastrointestinal protection are summarized.

CONCLUSION

Based on the summary of the research work of D. officinale, we systematically show the chemical composition of the plant, and concluded the relationship of those composition with plant habitat together with the relationship between the structure of chemical components and pharmacological activity. Moreover, we suggest that some of small molecule compounds could also be quality control of D. officinale besides polysaccharides.

Structural diversification of bioactive bibenzyls through modular co-culture leading to the discovery of a novel neuroprotective agent

Bibenzyls, a kind of important plant polyphenols, have attracted growing attention for their broad and remarkable pharmacological activities. However, due to the low abundance in nature, uncontrollable and environmentally unfriendly chemical synthesis processes, these compounds are not readily accessible. Herein, one high-yield bibenzyl backbone-producing Escherichia coli strain was constructed by using a highly active and substrate-promiscuous bibenzyl synthase identified from Dendrobium officinale in combination with starter and extender biosynthetic enzymes. Three types of efficiently post-modifying modular strains were engineered by employing methyltransferases, prenyltransferase, and glycosyltransferase with high activity and substrate tolerance together with their corresponding donor biosynthetic modules. Structurally different bibenzyl derivatives were tandemly and/or divergently synthesized by co-culture engineering in various combination modes. Especially, a prenylated bibenzyl derivative (12) was found to be an antioxidant that exhibited potent neuroprotective activity in the cellular and rat models of ischemia stroke. RNA-seq, quantitative RT-PCR, and Western-blot analysis demonstrated that 12 could up-regulate the expression level of an apoptosis-inducing factor, mitochondria associated 3 (Aifm3), suggesting that Aifm3 might be a new target in ischemic stroke therapy. This study provides a flexible plug-and-play strategy for the easy-to-implement synthesis of structurally diverse bibenzyls through a modular co-culture engineering pipeline for drug discovery.

Pandanus amaryllifolius Exhibits In Vitro Anti-Amyloidogenic Activity and Promotes Neuroprotective Effects in Amyloid-β-Induced SH-SY5Y Cells

Accumulation of amyloid-beta (Aβ) plaques leading to oxidative stress, mitochondrial damage, and cell death is one of the most accepted pathological hallmarks of Alzheimer’s disease (AD). Pandanus amaryllifolius, commonly recognized as fragrant screw pine due to its characteristic smell, is widely distributed in Southeast Asia and is consumed as a food flavor. In search for potential anti-AD agents from terrestrial sources, P. amaryllifolius was explored for its in vitro anti-amyloidogenic and neuroprotective effects. Thioflavin T (ThT) assay and the high-throughput screening multimer detection system (MDS-HTS) assay were used to evaluate the extracts’ potential to inhibit Aβ aggregations and oligomerizations, respectively. The crude alcoholic extract (CAE, 50 μg/mL) and crude base extract (CBE, 50 μg/mL) obstructed the Aβ aggregation. Interestingly, results revealed that only CBE inhibited the Aβ nucleation at 100 μg/mL. Both CAE and CBE also restored the cell viability, reduced the level of reactive oxygen species, and reversed the mitochondrial dysfunctions at 10 and 20 μg/mL extract concentrations in Aβ-insulted SY-SY5Y cells. In addition, the unprecedented isolation of nicotinamide from P. amaryllifolius CBE is a remarkable discovery as one of its potential bioactive constituents against AD. Hence, our results provided new insights into the promising potential of P. amaryllifolius extracts against AD and further exploration of other prospective bioactive constituents.

Chemical constituents from the stems of Dendrobium gratiosissimum and their biological activities

Eight C₆-C₃-based bibenzyl derivatives (dengraphenols A-G, K), three mono-bibenzyls (dengraphenols I, L-M), one bis-bibenzyl (dengraphenol H), one oxyneolignane (dengraphenol J), one phenanthrene (dengraphenol N), and one picrotoxane-type sesquiterpene (dengrasusane A) were isolated from the stems of Dendrobium gratiosissimum. The resolution of dengraphenols A-J by chiral HPLC afforded ten pairs of enantiomers [(±)-dengraphenols A-J]. Their structures with absolute configurations were elucidated on the basis of comprehensive spectroscopic analyses, computational calculation methods and single-crystal X-ray diffraction, among which twenty-four [(±)-dengraphenols A-E, (+)-dengraphenol F, (±)-dengraphenols G-J, dengraphenols K-N, dengrasusane A] were undescribed. Ten compounds [(±)-dengraphenol B, (±)-dengraphenols D-E, (±)-dengraphenol H, (-)-dengraphenol I and dengraphenol N)] showed potent cytotoxicity against eight human cancer cell lines (A431, A2780, H460, HCT8, BGC823, SW1990, Daoy, and HGC27) with IC₅₀ values of 3.77-9.75 μM. At a concentration of 10 μM, (-)-dengraphenol C, (±)-dengraphenol F, and (±)-dengraphenol K exhibited remarkable hepatoprotective activity against APAP-induced toxicity with a cell survival rate of 65.8%, 70.6% and 73.5%, respectively; dengraphenol N displayed significant anti-inflammatory effects; and dengraphenol K showed strong inhibitory activity against α-glucosidase with IC₅₀ values of 5.71 μM. These results would provide potential compounds for drug discovery.

Synbiotic Musa acuminata skin extract and Streptococcus salivarius K12 inhibit candida species biofilm formation

This study aimed to determine the effect of synbiotic Musa acuminata skin extract (MASE) and Streptococcus salivarius K12 (K12) on Candida species biofilm formation. Liquid chromatography quadrupole time-of-flight (LC-Q-TOF-MS) was conducted to characterize MASE. To determine the effect of synbiotic on Candida biofilm, 200 µL of RPMI-1640 containing Candida, K12, and MASE were pipetted into the same well and incubated at 37 °C for 72 h. A similar protocol was repeated with K12 or MASE to determine the probiotic and prebiotic effects, respectively. Dimorphism, biofilm biomass, and Candida total cell count (TCC) were determined. A total of 60 compounds were detected in MASE. C. albicans (ALT5) and Candida lusitaniae exhibited the highest reduction in biofilm biomass when co-cultured with prebiotic (77.70 ± 7.67%) and synbiotic (97.73 ± 0.28%), respectively. All Candida spp. had decreased TCC and hyphae when co-cultured with synbiotic. In conclusion, MASE and K12 inhibit Candida biofilm formation.

Design and synthesis of novel diosgenin-triazole hybrids targeting inflammation as potential neuroprotective agents

Alzheimer's disease is a progressive neurodegenerative disease, and its incidence is expected to increase as the global population ages. Recent studies provide increasing evidence that inflammation plays a key role in the pathogenesis and progression of AD. Diosgenin, an active ingredient in Dioscorea nipponica Makino, is a promising bioactive lead compound in the treatment of Alzheimer's disease, which exhibited anti-inflammatory activity. To search for more efficient anti-Alzheimer agents, a series of novel diosgenin-triazolyl hybrids were designed, synthesized, and their neuroprotective effects against oxygen-glucose deprivation-induced neurotoxicity and LPS-induced NO production were evaluated. Most of these new hybrids displayed better activities than DIO. In particular, the promising compound L6 not only demonstrated an excellent neuroprotective effect but also showed the best anti-inflammatory activity. The structure-activity relationship study illustrated that the introduction of benzyl or phenyl triazole did improve the activity, and the introduction of benzyl triazole was better than that of phenyl triazole. The results we obtained showed that the diosgenin skeleton could be a promising structural template for the development of new anti-Alzheimer drug candidates, and compound L6 has the potential to be an important lead compound for further research.

Neuroprotective Studies of Evodiamine in an Okadaic Acid-Induced Neurotoxicity

Background: Alzheimer’s disease (AD) is the most common neurodegenerative disease, and it manifests as progressive memory loss and cognitive decline. However, there are no effective therapies for AD, which is an urgent problem to solve. Evodiamine, one of the main bioactive ingredients of Evodia rutaecarpa, has been reported to ameliorate blood–brain barrier (BBB) permeability and improve cognitive impairment in ischemia and AD mouse models. However, whether evodiamine alleviates tauopathy remains unclear. This study aimed to examine whether evodiamine ameliorates tau phosphorylation and cognitive deficits in AD models. Methods: A protein phosphatase 2A inhibitor, okadaic acid (OA), was used to induce tau phosphorylation to mimic AD-like models in neuronal cells. Protein expression and cell apoptosis were detected using Western blotting and flow cytometry, respectively. Spatial memory/cognition was assessed using water maze, passive avoidance tests, and magnetic resonance imaging assay in OA-induced mice models, and brain slices were evaluated further by immunohistochemistry. Results: The results showed that evodiamine significantly reduced the expression of phosphor-tau, and further decreased tau aggregation and neuronal cell death in response to OA treatment. This inhibition was found to be via the inhibition of glycogen synthase kinase 3β, cyclin-dependent kinase 5, and mitogen-activated protein kinase pathways. In vivo results indicated that evodiamine treatment ameliorated learning and memory impairments in mice, whereas Western blotting and immunohistochemical analysis of the mouse brain also confirmed the neuroprotective effects of evodiamine. Conclusions: Evodiamine can decrease the neurotoxicity of tau aggregation and exhibit a neuroprotective effect. Our results demonstrate that evodiamine has a therapeutic potential for AD treatment.

Neuroprotective potential of the oxindole alkaloids isomitraphylline and mitraphylline in human neuroblastoma SH-SY5Y cells

The purified oxindole alkaloids, isomitraphylline and mitraphylline from Uncaria perrottetii, revealed their ability to break amyloid aggregates in vitro suggesting their therapeutic potentials in Alzheimer's disease (AD). Thioflavin-T assay for assessing amyloid-beta (Aβ) aggregation of these alkaloids exhibited inhibitions at 60.321% ± 2.61 (50 μM) for isomitraphylline and 43.17% ± 3.48 (50 μM) for mitraphylline. Neuroprotective effects were elaborated against Aβ-induced SH-SY5Y cells at 20 μM and 10 μM for isomitraphylline, and 20 μM for mitraphylline. In addition, both alkaloids attenuated and protected the H₂O₂-induced SH-SY5Y cell cytotoxicity at 20 μM. The intracellular ROS levels of SH-SY5Y cells from H₂O₂-induced oxidative stress were reduced at 20 μM and 10 μM, and the mitochondrial membrane potentials of Aβ-induced SH-SY5Y cells were protected at 20 μM. The overall results suggested the potentials of both alkaloids to target certain pathological biomarkers of AD and could be further investigated as therapeutic or preventive drug leads against AD.

Anti-Inflammatory and Tau Phosphorylation-Inhibitory Effects of Eupatin

Alzheimer's disease (AD), which is among the most prevalent neurodegenerative diseases, manifests as increasing memory loss and cognitive decline. Tau phosphorylation and aggregation are strongly linked to neurodegeneration, as well as associated with chronic neuroinflammatory processes. The anti-inflammation effects of natural products have led to wide recognition of their potential for use in treating and preventing AD. This study investigated whether eupatin, a polymethoxyflavonoid found in Artemisia species, has inhibitory effects on neuroinflammation and tau phosphorylation. We treated mouse macrophages and microglia cells with lipopolysaccharides (LPSs) to activate inflammatory signals, and we treated neuronal cells with a protein phosphatase 2A inhibitor, okadaic acid (OA), or transfection with pRK5-EGFP-Tau P301L plasmid to induce tau phosphorylation. The results indicated that eupatin significantly reduced the LPS-induced protein expression and phosphorylation of p65 and inducible nitric oxide synthase as well as downstream products interleukin 6 and nitrite, respectively. Furthermore, eupatin markedly inhibited the expression of phospho-tau in response to OA treatment and plasmid transfection. We discovered that this inhibition was achieved through the inhibition of glycogen synthase kinase 3β (GSK3β), and molecular docking results suggested that eupatin can sufficiently bind to the GSK3β active site. Our results demonstrate that eupatin has neuroprotective effects, making it suitable for AD treatment.

Mesenchymal Stem Cell-Conditioned Medium Improves Mitochondrial Dysfunction and Suppresses Apoptosis in Okadaic Acid-Treated SH-SY5Y Cells by Extracellular Vesicle Mitochondrial Transfer

BACKGROUND

Mesenchymal stem cells-conditioned medium (MSC-CM) provides a promising cell-free therapy for Alzheimer's disease (AD) mainly due to the paracrine of MSCs, but the precise mechanisms remain unclear. Studies suggests that mitochondrial dysfunction precedes the accumulation of amyloid-β plaques and neurofibrillary tangles, and involves in the onset and development of AD.

OBJECTIVE

In the present study, we evaluated the protective effects and explored the related-mitochondrial mechanisms of human umbilical cord derived MSC-CM (hucMSC-CM) in an AD model in vitro.

METHODS

To this end, an AD cellular model was firstly established by okadaic acid (OA)-treated SH-SY5Y cells, and then treated by hucMSC-CM to assess the oxidative stress, mitochondrial function, apoptosis, AD-related genes, and signaling pathways.

RESULTS

hucMSC-CM significantly deceased tau phosphorylated at Thr181 (p181-tau) level, which was increased in AD. hucMSC-CM also alleviated intracellular and mitochondrial oxidative stress in OA-treated SH-SY5Y cells. In addition, hucMSC-CM suppressed apoptosis and improved mitochondrial function in OA-treated SH-SY5Y cells. Flow cytometric analysis indicated that hucMSC-CM exerted the protective effects relying on or partly extracellular vesicle (EV) mitochondrial transfer from hucMSCs to OA-treated SH-SY5Y cells. Moreover, RNA sequencing data further demonstrated that hucMSC-CM regulated many AD-related genes, signaling pathways and mitochondrial function.

CONCLUSION

These results indicated that MSC-CM or MSC-EVs containing abundant mitochondria may provide a novel potential therapeutic approach for AD.

A Bibenzyl Component Moscatilin Mitigates Glycation-Mediated Damages in an SH-SY5Y Cell Model of Neurodegenerative Diseases through AMPK Activation and RAGE/NF-κB Pathway Suppression

Moscatilin can protect rat pheochromocytoma cells against methylglyoxal-induced damage. Elimination of the effect of advanced glycation end-products (AGEs) but activation of AMP-activated protein kinase (AMPK) are the potential therapeutic targets for the neurodegenerative diseases. Our study aimed to clarify AMPK signaling’s role in the beneficial effects of moscatilin on the diabetic/hyperglycemia-associated neurodegenerative disorders. AGEs-induced injury in SH-SY5Y cells was used as an in vitro neurodegenerative model. AGEs stimulation resulted in cellular viability loss and reactive oxygen species production, and mitochondrial membrane potential collapse. It was observed that the cleaved forms of caspase-9, caspase-3, and poly (ADP-ribose) polymerase increased in SH-SY5Y cells following AGEs exposure. AGEs decreased Bcl-2 but increased Bax and p53 expression and nuclear factor kappa-B activation in SH-SY5Y cells. AGEs also attenuated the phosphorylation level of AMPK. These AGEs-induced detrimental effects were ameliorated by moscatilin, which was similar to the actions of metformin. Compound C, an inhibitor of AMPK, abolished the beneficial effects of moscatilin on the regulation of SH-SY5Y cells’ function, indicating the involvement of AMPK. In conclusion, moscatilin offers a promising therapeutic strategy to reduce the neurotoxicity or AMPK dysfunction of AGEs. It provides a potential beneficial effect with AGEs-related neurodegenerative diseases.

Recent research progress on natural small molecule bibenzyls and its derivatives in Dendrobium species

Orchidaceous plant Dendrobium genus is often used as a tonic, and its phenolic components have attracted attention for its anti-tumor and anti-diabetic complications. Bibenzyls is one of the essential phenolic active ingredients in the Dendrobium genus. At present, 89 bibenzyl derivatives have been extracted and identified from 46 Dendrobium species. The activity studies have shown that 42 compounds have pharmaceutical activity. Among them, 23 compounds showed antitumor activity; 7 compounds showed anti-diabetes and its complications activity; 10 compounds exhibited neuroprotective effects; 18 compounds showed antioxidant effects; 11 compounds had anti-inflammatory activity; 3 compounds had Antiplatelet aggregation effects; 3 compounds had antibacterial and antiviral effects. The Bibenzyls is small-molecular compounds of natural origin and widely sourced. Previous studies showed that the bibenzyls has good anti-tumor, anti-diabetes and its complications, and neuroprotective effects, and it has great potential for treating tumors, diabetes and its complications, Alzheimer's disease (AD) and Parkinson's disease (PD). Additionally, compounds such as moscatilin (1), gigantol (2) and chrysotoxine (3) have been further studied as lead compounds, and compounds exhibited therapeutical effects had been synthesized. Enough pieces of evidences have shown that the Bibenzyls have good development prospects. This article reviews the pharmacological effects of bibenzyls in Dendrobium species and provides an idea for its further development.

Effect of (m)RVD-hemopressin against Aβ1-42-induced apoptosis and inhibition of neurite outgrowth in SH-SY5Y cells

Alzheimer's disease (AD) is a serious neurodegenerative disease. Senile plaques (SPs) in the extracellular space and neurofibrillary tangles (NFTs) in the intracellular areas of the brain are two typical features of AD. SPs and NFTs are composed of amyloid-β (Aβ) aggregates and hyperphosphorylated Tau, respectively. (m)RVD-hemopressin (RVD), which is derived from mouse brain peptide, binds to the cannabinoid 1 receptor (CB1R) as an agonist. Our previous study indicated that RVD reversed Aβ1-42-induced memory impairment in mice. Here, we investigated the underlying molecular mechanism of RVD on Aβ1-42-induced neurotoxicity in retinoic acid-differentiated human neuroblastoma SH-SY5Y cells. Cell viability and neurite outgrowth were investigated by live cell imaging and analysis instrument. We found that RVD reversed Aβ1-42-induced Tau phosphorylation, apoptosis and suppression of neurite outgrowth and the synapse-associated protein postsynaptic density protein 95 (PSD-95) by inhibiting the activity of protein kinase A (PKA) and glycogen synthase kinase 3β (GSK-3β). Combined treatment with AM251 (a CB1R antagonist) blocked the effects of RVD. In conclusion, RVD may be a potential therapeutic agent for the treatment of cognitive dysfunctions, such as Alzheimer's disease.

Protective Effects of Compounds from Cimicifuga dahurica against Amyloid Beta Production in Vitro and Scopolamine-Induced Memory Impairment in Vivo

Cimicifuga dahurica has traditionally been used as an antipyretic, analgesic, and anti-inflammatory agent and as a treatment for uterine and anal prolapse. This study has investigated the potential beneficial effects of this medicinal plant and its components on Alzheimer's disease (AD) with a focus on amyloid beta (Aβ) production and scopolamine-induced memory impairment in mice. An ethanol extract from C. dahurica roots decreased Aβ production in APP-CHO cells [Chinese hamster ovarian (CHO) cells stably expressing amyloid precursor protein (APP)], as determined by an enzyme-linked immunosorbent assay and Western blot analysis. Then, the compounds isolated from C. dahurica were tested for their antiamyloidogenic activities. Four compounds (1-4) efficiently interrupted Aβ generation by suppressing the level of β-secretase in APP-CHO cells. Moreover, the in vivo experimental results demonstrated that compound 4 improved the cognitive performances of mice with scopolamine-induced disruption on behavioral tests and the expression of memory-related proteins. Taken together, these results suggest that C. dahurica and its constituents are potential agents for preventing or alleviating the symptoms of AD.