Ginkgo biloba Extract (EGb761), Cholinesterase Inhibitors, and Memantine for the Treatment of Mild-to-Moderate Alzheimer's Disease: A Network Meta-Analysis

Algorithmic Spaced Retrieval Enhances Long-Term Memory in Alzheimer Disease: Case-Control Pilot Study

BACKGROUND

Spaced retrieval is a learning technique that involves engaging in repeated memory testing after increasingly lengthy intervals of time. Spaced retrieval has been shown to improve long-term memory in Alzheimer disease (AD), but it has historically been difficult to implement in the everyday lives of individuals with AD.

OBJECTIVE

This research aims to determine, in people with mild cognitive impairment (MCI) due to AD, the efficacy and feasibility of a mobile app that combines spaced retrieval with a machine learning algorithm to enhance memory retention. Specifically, the app prompts users to answer questions during brief daily sessions, and a machine learning algorithm tracks each user's rate of forgetting to determine the optimal spacing schedule to prevent anticipated forgetting.

METHODS

In this pilot study, 61 participants (young adults: n=21, 34%; healthy older adults: n=20, 33%; people with MCI due to AD: n=20, 33%) used the app for 4 weeks to learn new facts and relearn forgotten name-face associations. Participation during the 4-week period was characterized by using the app once per day to answer 15 questions about the facts and names. After the 4-week learning phase, participants completed 2 recognition memory tests approximately 1 week apart, which tested memory for information they had studied using the app as well as information they had not studied.

RESULTS

After using the mobile app for 1 month, every person with MCI due to AD demonstrated improvements in memory for new facts that they had studied via the app compared to baseline (P<.001). All but one person with MCI due to AD (19/20, 95%) showed improvements of more than 10 percentage points, comparable to the improvements shown by young adults and healthy older adults. Memory for name-face associations was similarly improved for all participant groups after using the app but to a lesser degree. Furthermore, for both new facts and name-face associations, we found no memory decay for any participant group after they took a break of approximately 1 week from using the app at the end of the study. Regarding usability, of the 20 people with MCI due to AD, 16 (80%) self-adhered to the app's automated practice schedule, and half of them (n=10, 50%) expressed an interest in continuing to use it.

CONCLUSIONS

These results demonstrate early evidence that spaced retrieval mobile apps are both feasible for people with early-stage AD to use in their everyday lives and effective for supporting memory retention of recently learned facts and name-face associations.

Neuropsychological Assessment for Early Detection and Diagnosis of Dementia: Current Knowledge and New Insights

Dementia remains an underdiagnosed syndrome, and there is a need to improve the early detection of cognitive decline. This narrative review examines the role of neuropsychological assessment in the characterization of cognitive changes associated with dementia syndrome at different states. The first section describes the early indicators of cognitive decline and the major barriers to their identification. Further, the optimal cognitive screening conditions and the most widely accepted tests are described. The second section analyzes the main differences in cognitive performance between Alzheimer's disease and other subtypes of dementia. Finally, the current challenges of neuropsychological assessment in aging/dementia and future approaches are discussed. Essentially, we find that current research is beginning to uncover early cognitive changes that precede dementia, while continuing to improve and refine the differential diagnosis of neurodegenerative disorders that cause dementia. However, neuropsychology faces several barriers, including the cultural diversity of the populations, a limited implementation in public health systems, and the adaptation to technological advances. Nowadays, neuropsychological assessment plays a fundamental role in characterizing cognitive decline in the different stages of dementia, but more efforts are needed to develop harmonized procedures that facilitate its use in different clinical contexts and research protocols.

Pharmacologic and Nutritional Interventions for Early Alzheimer's Disease: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background

Early intervention is essential for meaningful disease modification in Alzheimer's disease (AD).

Objective

We aimed to determine the efficacy and safety of pharmacologic and nutritional interventions for early AD.

Methods

PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov were searched from database inception until 1 September 2023. We included randomized controlled trials that evaluated the efficacy of interventions in early AD. Only interventions that demonstrated efficacy compared to placebo were included in the network meta-analysis (NMA). Then we performed frequentist fixed-effects NMA to rank the interventions. GRADE criteria were used to evaluate the level of evidence.

Results

Fifty-eight trials including a total of 33,864 participants and 48 interventions were eligible for inclusion. Among the 48 interventions analyzed, only 6 (12.5%) treatments- ranging from low to high certainty- showed significant improvement in cognitive decline compared to placebo. High certainty evidence indicated that donanemab (standardized mean difference [SMD] -0.239, 95% confidence interval [CI] -0.343 to -0.134) and lecanemab (SMD -0.194, 95% CI -0.279 to -0.108) moderately slowed the clinical progression in patients with amyloid pathology. Additionally, methylphenidate, donepezil, LipiDiDiet, and aducanumab with low certainty showed significant improvement in cognitive decline compared to placebo. However, there was no significant difference in serious adverse events as reported between the six interventions and placebo.

Conclusions

Only 12.5% of interventions studied demonstrated efficacy in reducing cognitive impairment in early AD. Donanemab and lecanemab have the potential to moderately slow the clinical progression in patients with amyloid pathology. Further evidence is required for early intervention in AD.

Systematic review and network meta-analysis of efficacy and safety of interventions for preventing anti-tuberculosis drug induced liver injury

Anti-tuberculosis drug induced liver injury (Anti-TB DILI) is the most common adverse events (AEs) necessitating therapy interruption but there is no preventing regimen. This study aimed to examine the efficacy and safety of herbs/alternative medicines for preventing anti-TB DILI. Relevant articles were identified through a systematic search in 5 international databases from inception till March 2022. All randomized controlled trials (RCT) assessing the effects of herbal or alternative medicines against anti-TB DILI were included. The network meta-analysis (NMA) was used to synthesize the evidence for preventing hepatotoxicity using a random-effects model. A total of 3423 patients from 14 RCTs were included. The NMA indicated that supplementation of Turmeric plus Tinospora cordifolia (RR 0.07; 95% CI 0.02 to 0.28), and N-acetyl cysteine (NAC) (RR 0.09; 95% CI 0.01 to 0.75) significantly reduced the incidence of anti-TB DILI compared with placebo. In addition, poly herbal product significantly reduced alkaline phosphatase (ALP) (MD - 21.80; 95% CI - 33.80 to - 9.80) and total bilirubin (Tbil) compared with placebo (MD - 0.51; 95% CI - 0.76 to - 0.26). There was no statistically significant difference in the occurrence of AEs in any intervention. In conclusion, Turmeric plus Tinospora cordifolia, NAC and poly-herbal product may provide benefit for preventing anti-TB DILI in TB patients. However, these findings are based on a small number of studies. Additional studies are warranted to confirm the findings.

Efficacy and acceptability of anti-inflammatory eicosapentaenoic acid for cognitive function in Alzheimer's dementia: A network meta-analysis of randomized, placebo-controlled trials with omega-3 fatty acids and FDA-approved pharmacotherapy

Alzheimer's dementia (AD) is a major contributor to global disability, and effective therapies to modify disease progression are currently lacking. The neuro-inflammatory theory is a potential etiology underlying this neurodegenerative disease. Previous randomized, controlled trials (RCTs) have provided inconclusive results regarding efficacy of omega-3 polyunsaturated fatty acids (PUFAs) regimens, which might provide anti-inflammatory benefits in the management of AD, in improving cognitive function among participants with AD. The objective of this frequentist-model based network meta-analysis (NMA) was to evaluate the potential advantages of omega-3 PUFAs and currently FDA-approved medications for AD on overall cognitive function in AD individuals. The primary outcomes were: (1) changes in cognitive function, and (2) acceptability, which refers to all-cause discontinuation. Additionally, secondary outcomes included quality of life, behavioral disturbances and safety/tolerability, which was assessed through the frequency of any reported adverse event. This NMA included 52 RCTs (6 with omega-3 PUFAs and 46 with FDA-approved medications) involving 21,111 participants. The results showed that long-term high-dose (1500-2000 mg/day) of eicosapentaenoic acid (EPA)-dominant omega-3 PUFAs augmented with anti-oxidants had the highest potential for cognitive improvement among all investigated treatments [standardized mean difference = 3.00, 95% confidence intervals (95 %CIs) = 1.84-4.16]. Compared to placebo, omega-3 PUFAs had similar acceptability [odds ratio (OR) = 0.46, 95 %CIs = 0.04 to 5.87] and safety profiles (OR = 1.24, 95 %CIs = 0.66 to 2.33)o. These findings support the potential neurotherapeutic effects of high dosage EPA-dominant omega-3 PUFAs for the amelioration of cognitive decline in patients with AD. Future large-scale, long-term RCTs should focus on different dosages of EPA-dominant omega-3 PUFAs regimens on improving cognitive dysfunction in patients with AD at different levels of inflammatory status and psychopathology.

Mapping new pharmacological interventions for cognitive function in Alzheimer's disease: a systematic review of randomized clinical trials

Background and Objective: Alzheimer's disease (AD) is a progressive neurodegenerative disorder, that is, characterized by cognitive decline. To date, there are no effective treatments for AD. Therefore, the objective of this study was to map new perspectives on the effects of pharmacological treatment on cognitive function and the overall psychological state in patients with AD. Methods: Two independent researchers searched for randomized clinical trials (RCTs) exploring new pharmacological approaches related to cognition in Alzheimer's disease in adults from 2018 to 2023 in PubMed, Web of Science, Scopus, and Cochrane Library databases. A total of 17 RCTs were included in this review. Results: The results show that in recent years, new drugs have been tested in patients with Alzheimer's disease, including masitinib, methylphenidate, levetiracetam, Jiannao Yizhi, and Huannao Yicong formulas. Most studies have been conducted in populations with mild to moderate Alzheimer's disease. Conclusion: Although some of the drugs found suggested improvement in cognitive function, the scarcity of available studies highlights the need for further research in this area. Systematic review registration: [www.crd.york.ac.uk/prospero], identifier [CRD42023409986].

Nicotinic acetylcholine receptors and learning and memory deficits in Neuroinflammatory diseases

Animal survival depends on cognitive abilities such as learning and memory to adapt to environmental changes. Memory functions require an enhanced activity and connectivity of a particular arrangement of engram neurons, supported by the concerted action of neurons, glia, and vascular cells. The deterioration of the cholinergic system is a common occurrence in neurological conditions exacerbated by aging such as traumatic brain injury (TBI), posttraumatic stress disorder (PTSD), Alzheimer's disease (AD), and Parkinson's disease (PD). Cotinine is a cholinergic modulator with neuroprotective, antidepressant, anti-inflammatory, antioxidant, and memory-enhancing effects. Current evidence suggests Cotinine's beneficial effects on cognition results from the positive modulation of the α7-nicotinic acetylcholine receptors (nAChRs) and the inhibition of the toll-like receptors (TLRs). The α7nAChR affects brain functions by modulating the function of neurons, glia, endothelial, immune, and dendritic cells and regulates inhibitory and excitatory neurotransmission throughout the GABA interneurons. In addition, Cotinine acting on the α7 nAChRs and TLR reduces neuroinflammation by inhibiting the release of pro-inflammatory cytokines by the immune cells. Also, α7nAChRs stimulate signaling pathways supporting structural, biochemical, electrochemical, and cellular changes in the Central nervous system during the cognitive processes, including Neurogenesis. Here, the mechanisms of memory formation as well as potential mechanisms of action of Cotinine on memory preservation in aging and neurological diseases are discussed.

Neuroprotective Potential of Biflavone Ginkgetin: A Review

Neurological disorders are becoming more common, and there is an intense search for molecules that can help treat them. Several natural components, especially those from the flavonoid group, have shown promising results. Ginkgetin is the first known biflavonoid, a flavonoid dimer isolated from ginkgo (Ginkgo biloba L.). Later, its occurrence was discovered in more than 20 different plant species, most of which are known for their use in traditional medicine. Herein we have summarized the data on the neuroprotective potential of ginkgetin. There is evidence of protection against neuronal damage caused by ischemic strokes, neurotumors, Alzheimer's disease (AD), and Parkinson's disease (PD). Beneficial effects in ischemic strokes have been demonstrated in animal studies in which injection of ginkgetin before or after onset of the stoke showed protection from neuronal damage. AD protection has been the most studied to date. Possible mechanisms include inhibition of reactive oxygen species, inhibition of β-secretase, inhibition of Aβ fibril formation, amelioration of inflammation, and antimicrobial activity. Ginkgetin has also shown positive effects on the relief of PD symptoms in animal studies. Most of the available data are from in vitro or in vivo animal studies, where ginkgetin showed promising results, and further clinical studies should be conducted.

Efficacy and safety of herbal medicine on dementia and cognitive function: An umbrella review of systematic reviews and meta-analysis

This study aims to summarize the effects of herbs on dementia and assess the strength of evidence. Six international and local databases were searched from inception to October 2021 for systematic reviews and meta-analyses of clinical trials investigated the effects of herbal medicine on dementia or cognitive function. Two researchers independently extracted data, assessed the methodological quality, and rated the credibility of evidence according to established criteria. Thirty-seven articles evaluating 13 herbal medicines were included. Of these, 65% were rated critically low using AMSTAR2. Of 90 unique outcomes, 41 (45.6%) were statistically significant based on random effects model (p ≤ .05). Only 3 herbs were supported by suggestive evidence whereas the others were supported by weak evidence. The suggestive evidence supported benefits of Chinese herbal medicine (CHM) plus pharmacotherapy (WMD:1.84; 95% CI: 1.34, 2.35) and Vinpocetine (WMD: -0.94; 95%CI: -1.50, -0.38) on improving cognitive function assessing by Montreal Cognitive Assessment and Syndrom-Kurz-Test, respectively. Moreover, suggestive evidence supported benefit of Huperzia serrata on improving Activities of Daily Living (WMD:-7.18; 95%CI: -9.12, -5.23). No SAE was reported. In conclusion, several herbs were used for improving dementia and cognitive function but recent evidence were limited by the small sample size and poor methodological quality. Therefore, further large and well-designed studies are needed to support the evidence.

Efficacy of pharmacotherapy and non-pharmacotherapy of Alzheimer dementia: A protocol for systematic review and meta-analysis

BACKGROUND

Alzheimer disease (AD) is the most common cause of dementia worldwide. Despite the publication of numerous systematic reviews and meta-analyses that have summarized the evidence associated with pharmacotherapies (PTs) and non-pharmacotherapies (NPTs) for the wide range of interventions available for AD treatment, their comparative safety and efficacy remains insufficiently defined.

METHODS

Systematic reviews of randomized controlled trials (RCTs) will be selected according to the following criteria: conducted in elderly patients aged 60 years or older with AD living in community or institutionalized settings, applied pairwise meta-analysis (PMA) or network meta-analysis (NMA) approaches providing pooled relative treatment effects for at least 1 pair of PTs or NPTs, and providing at least 1 of the following outcomes for patients/caregivers: cognitive, functional status, behavior, quality of life (QoL), and caregiver stress or burden. All article screening, data extraction, and risk of bias assessment will be completed independently by 2 reviewers. Relative treatment rankings will be reported with mean ranks and surface under the cumulative ranking curves.

RESULTS AND CONCLUSION

We will determine the most efficacious treatment strategies for AD patients from the most highly ranked treatments. These results will help to guide clinical decision-making and improve patient care.

The Dose and Duration-dependent Association between Melatonin Treatment and Overall Cognition in Alzheimer's Dementia: A Network Meta- Analysis of Randomized Placebo-Controlled Trials

BACKGROUND

While Alzheimer's dementia (AD) has a prevalence as high as 3-32% and is associated with cognitive dysfunction and the risk of institutionalization, no efficacious and acceptable treatments can modify the course of cognitive decline in AD. Potential benefits of exogenous melatonin for cognition have been divergent across trials.

OBJECTIVE

The current network meta-analysis (NMA) was conducted under the frequentist model to evaluate the potential beneficial effects of exogenous melatonin supplementation on overall cognitive function in participants with AD in comparison to other FDA-approved medications (donepezil, galantamine, rivastigmine, memantine, and Namzaric).

METHODS

The primary outcome was the changes in the cognitive function [measured by mini-mental state examination (MMSE)] after treatment in patients with Alzheimer's dementia. The secondary outcomes were changes in the quality of life, behavioral disturbance, and acceptability (i.e., drop-out due to any reason and rate of any adverse event reported).

RESULTS

The current NMA of 50 randomized placebo-controlled trials (RCTs) revealed the medium-term lowdose melatonin to be associated with the highest post-treatment MMSE (mean difference = 1.48 in MMSE score, 95% confidence intervals [95% CIs] = 0.51 to 2.46) and quality of life (standardized mean difference = -0.64, 95% CIs = -1.13 to -0.15) among all of the investigated medications in the participants with AD. Finally, all of the investigated exogenous melatonin supplements were associated with similar acceptability as was the placebo.

CONCLUSION

The current NMA provides evidence for the potential benefits of exogenous melatonin supplementation, especially medium-term low-dose melatonin, in participants with AD.

A New Insight into an Alternative Therapeutic Approach to Restore Redox Homeostasis and Functional Mitochondria in Neurodegenerative Diseases

Neurodegenerative diseases are accompanied by oxidative stress and mitochondrial dysfunction, leading to a progressive loss of neuronal cells, formation of protein aggregates, and a decrease in cognitive or motor functions. Mitochondrial dysfunction occurs at the early stage of neurodegenerative diseases. Protein aggregates containing oxidatively damaged biomolecules and other misfolded proteins and neuroinflammation have been identified in animal models and patients with neurodegenerative diseases. A variety of neurodegenerative diseases commonly exhibits decreased activity of antioxidant enzymes, lower amounts of antioxidants, and altered cellular signalling. Although several molecules have been approved clinically, there is no known cure for neurodegenerative diseases, though some drugs are focused on improving mitochondrial function. Mitochondrial dysfunction is caused by oxidative damage and impaired cellular signalling, including that of peroxisome proliferator-activated receptor gamma coactivator 1α. Mitochondrial function can also be modulated by mitochondrial biogenesis and the mitochondrial fusion/fission cycle. Mitochondrial biogenesis is regulated mainly by sirtuin 1, NAD⁺, AMP-activated protein kinase, mammalian target of rapamycin, and peroxisome proliferator-activated receptor γ. Altered mitochondrial dynamics, such as increased fission proteins and decreased fusion products, are shown in neurodegenerative diseases. Due to the restrictions of a target-based approach, a phenotype-based approach has been performed to find novel proteins or pathways. Alternatively, plasma membrane redox enzymes improve mitochondrial function without the further production of reactive oxygen species. In addition, inducers of antioxidant response elements can be useful to induce a series of detoxifying enzymes. Thus, redox homeostasis and metabolic regulation can be important therapeutic targets for delaying the progression of neurodegenerative diseases.

The Efficacy and Safety of Alzheimer's Disease Therapies: An Updated Umbrella Review

BACKGROUND

Evidence summaries for efficacy and safety of frequently employed treatments of Alzheimer's disease (AD) are sparse.

OBJECTIVE

We aimed to perform an updated umbrella review to identify an efficacious and safe treatment for AD patients.

METHODS

We conducted a search for meta-analyses and systematic reviews on the Embase, PubMed, The Cochrane Library, and Web of Science to address this knowledge gap. We examined the cognitive functions, behavioral symptoms, global clinical assessment, and Activities of Daily Living as efficacy endpoints, and the incidence of adverse events as safety profiles.

RESULTS

Sixteen eligible papers including 149 studies were included in the umbrella review. The results showed that AChE inhibitors (donepezil, galantamine, rivastigmine, Huperzine A), Ginkgo biloba, and cerebrolysin appear to be beneficial for cognitive, global performances, and activities of daily living in patients with AD. Furthermore, anti-Aβ agents are unlikely to have an important effect on slowing cognitive or functional impairment in mild to moderate AD.

CONCLUSION

Our study demonstrated that AChE inhibitors, Ginkgo biloba, and cerebrolysin are the optimum cognitive and activities of daily living medication for patients with AD.

The Use of Ginkgo Biloba L. as a Neuroprotective Agent in the Alzheimer's Disease

Alzheimer's disease, a neurodegenerative disease, is one of the most common causes of dementia if elderly people worldwide. Alzheimer's disease leads to the alienation of individuals and their exclusion from social and professional life. It is characterized mainly by the degradation of memory and disorientation, which occurs as a result of the loss of neuronal structure and function in different brain areas. In recent years, more and more attention has been paid to use in the treatment of natural bioactive compounds that will be effective in neurodegenerative diseases, including Alzheimer's disease. G. biloba L. and its most frequently used standardized extract (EGb 761), have been used for many years in supportive therapy and in the prevention of cognitive disorders. The paper presents an overview of reports on the pathogenesis of Alzheimer's disease, as well as a summary of the properties of G. biloba extract and its effects on the possible pathogenesis of the disease. By exploring more about the pathogenesis of the disease and the benefits of G. biloba extract for patients with Alzheimer's disease, it will be possible to create an individualized therapeutic protocol to optimize the treatment.

Discovery of a naturally occurring broad-spectrum inhibitor against gut bacterial β-glucuronidases from Ginkgo biloba

Gut bacterial β-glucuronidases (GUS) play an important role in deconjugation of various O-glucuronides, which are tightly linked with the drug-induced intestinal toxicity. Increasing evidence has indicated that inhibition of bacterial GUS could alleviate GUS-associated intestinal toxicity, but the potent and broad-spectrum inhibitors against multiple bacterial GUS have been rarely reported. This study aimed to find potent and broad-spectrum GUS inhibitors from Ginkgo biloba. It was found that amentoflavone displayed relatively strong inhibition on three GUS including CpGUS, SpasGUS and EcGUS. Further investigations demonstrated that amentoflavone could inhibit GUS-mediated PNPG hydrolysis in a dose-dependent manner with IC₅₀ values of 2.36 μM, 2.88 μM and 3.43 μM for CpGUS, SpasGUS and EcGUS, respectively. Inhibition kinetic studies showed that amentoflavone functioned as a non-competitive inhibitor against all tested GUS with K_i values of less than 2 μM. Docking simulations indicated that amentoflavone could tightly bind on allosteric sites of three GUS mainly via hydrogen bonding interactions, and the number of hydroxyl groups of amentoflavone played crucial roles in these interactions. Collectively, our findings suggested that amentoflavone was a potent broad-spectrum inhibitor against bacterial GUS, which can be used as a promising lead compound for developing novel agents to alleviate GUS-associated intestinal toxicity.

Medicinal herbs and nutritional supplements for dementia therapy: potential therapeutic targets and clinical evidence

Spices and herbs have been used for medicinal purposes for centuries. Also, in the last decades, the use of different nutritional supplements has been implemented to treat all kinds of diseases, including those that present an alteration in cognitive functioning. Dementia is a clinical syndrome in which a person's mental and cognitive capacities gradually decline. As the disease progresses, the person's autonomy diminishes. As there is not an effective treatment to prevent progressive deterioration in many of these pathologies, nutritional interventions have been, and still are, one of the most widely explored therapeutic possibilities. In this review, we have discussed a great number of potentially interesting plants, nutritional derivatives and probiotics for the treatment of dementia around the world. Their action mechanisms generally involve neuroprotective effects via anti-inflammatory, antioxidant, anti-apoptotic, b-amyloid and tau anti-aggregate actions; brain blood flow improvement, and effects on synaptic cholinergic and dopaminergic neurotransmission, which may optimize cognitive performance in patients with cognitive impairment. As for their efficacy in patients with cognitive impairment and/or dementias, evidence is still scarce and/or their outcomes are controversial. We consider that many of these substances have promising therapeutic properties. Therefore, the scientific community has to continue with a more complete research focused on both identifying possible action mechanisms and carrying out clinical trials, preferably randomized double-blind ones, with a greater number of patients, a long-term follow-up, dose standardization and the use of current diagnosis criteria.

Stachydrine Inhibits PC12 Cell Apoptosis Induced by Aβ25-35 in an in vitro Cell Model of Neurocognitive Disorders

Background:

Abnormal deposition of amyloid beta (Aβ) is considered the primary cause of neurocognitive disorders (NCDs). Inhibiting cytotoxicity is an important aspect of the treatment of NCDs. Stachydrine (STA) has been widely used for gynecological and cardiovascular disorders. However, whether STA has protective functions in PC12 cells treated with Aβ25-35 remains unclear.

Introduction:

Traditional Chinese Medicine, stachydrine (STA), is a water-soluble alkaloid of Leonurus heterophyllus, which can inhibit cell apoptosis, suppress tumor growth, maintain homeostasis of myocardial cells, and alleviate endothelial dysfunction. This study will investigate the effect of STA on inhibiting PC12 cell apoptosis induced by Aβ25-35 in an in vitro cell model of neurocognitive disorders.

Methods:

The differentially expressed genes (DEGs) in cells treated with STA were analyzed according to the Gene Expression Omnibus (GSE) 85871 data, and the STITCH database was used to identify the target genes of STA. PC12 cells were treated with Aβ25-35 and/or STA, 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed and lactate dehydrogenase (LDH) activity was determined. The cell cycle distribution was detected by flow cytometry, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) or Western blotting were used to detect the expression of genes or proteins.

Results:

GSE85871 data showed 37 upregulated and 48 downregulated genes among the DEGs affected by STA. The results from the STITCH database showed that RPS8 and EED were target genes of STA. GSE1297 analysis showed the 13 most significantly upregulated genes. STA might affect the occurrence of NCDs through the interaction of TP53 with EED and RPS8. Finally, Aβ25-35 promoted apoptosis and LDH release of PC-12 cells, arrested the cell cycle in the G2/M phase, and inhibited the expression of the RPS8, EED, Bcl-2 and P53 genes. STA could reverse the effect of Aβ25-35.

Conclusion:

STA may play an important role in inhibiting apoptosis induced by Aβ25-35 by targeting the RPS8 and EED genes in the NCDs model in vitro.

Epileptic Mechanisms Shared by Alzheimer's Disease: Viewed via the Unique Lens of Genetic Epilepsy

Our recent work on genetic epilepsy (GE) has identified common mechanisms between GE and neurodegenerative diseases including Alzheimer's disease (AD). Although both disorders are seemingly unrelated and occur at opposite ends of the age spectrum, it is likely there are shared mechanisms and studies on GE could provide unique insights into AD pathogenesis. Neurodegenerative diseases are typically late-onset disorders, but the underlying pathology may have already occurred long before the clinical symptoms emerge. Pathophysiology in the early phase of these diseases is understudied but critical for developing mechanism-based treatment. In AD, increased seizure susceptibility and silent epileptiform activity due to disrupted excitatory/inhibitory (E/I) balance has been identified much earlier than cognition deficit. Increased epileptiform activity is likely a main pathology in the early phase that directly contributes to impaired cognition. It is an enormous challenge to model the early phase of pathology with conventional AD mouse models due to the chronic disease course, let alone the complex interplay between subclinical nonconvulsive epileptiform activity, AD pathology, and cognition deficit. We have extensively studied GE, especially with gene mutations that affect the GABA pathway such as mutations in GABA_A receptors and GABA transporter 1. We believe that some mouse models developed for studying GE and insights gained from GE could provide unique opportunity to understand AD. These include the pathology in early phase of AD, endoplasmic reticulum (ER) stress, and E/I imbalance as well as the contribution to cognitive deficit. In this review, we will focus on the overlapping mechanisms between GE and AD, the insights from mutations affecting GABA_A receptors, and GABA transporter 1. We will detail mechanisms of E/I imbalance and the toxic epileptiform generation in AD, and the complex interplay between ER stress, impaired membrane protein trafficking, and synaptic physiology in both GE and AD.

Does the application of acetylcholinesterase inhibitors in the treatment of Alzheimer's disease lead to depression?

Introduction: Alzheimer's disease and depression are health conditions affecting millions of people around the world. Both are strongly related to the level of the neurotransmitter acetylcholine. Since cholinergic deficit is characteristic of Alzheimer's disease, acetylcholinesterase inhibitors are applied as relevant drugs for the treatment of this disease, elevating the level of acetylcholine. On the other hand, a high level of acetylcholine is found to be associated with the symptoms of clinical depression.Areas covered: This article aims to discuss if acetylcholinesterase inhibitors used as anti-Alzheimer's drugs could be the cause of the symptoms of clinical depression often linked to this neurological disorder. Emphasis will be put on drugs currently in use and on newly investigated natural products, which can inhibit AChE activity.Expert opinion: Currently, it is not proven that the patient treated for Alzheimer's disease is prone to increased risk for depression due to the acetylcholinesterase inhibition, but there are strong indications. The level of acetylcholine is not the only factor in highly complicated diseases like AD and depression. Still, it needs to be considered isolated, keeping in mind the nature of presently available therapy, especially during a rational drug design process.

COVID-19 and Alzheimer's disease: how one crisis worsens the other

Alzheimer’s disease (AD) has emerged as a key comorbidity of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The morbidity and mortality of COVID-19 are elevated in AD due to multiple pathological changes in AD patients such as the excessive expression of viral receptor angiotensin converting enzyme 2 and pro-inflammatory molecules, various AD complications including diabetes, lifestyle alterations in AD, and drug-drug interactions. Meanwhile, COVID-19 has also been reported to cause various neurologic symptoms including cognitive impairment that may ultimately result in AD, probably through the invasion of SARS-CoV-2 into the central nervous system, COVID-19-induced inflammation, long-term hospitalization and delirium, and post-COVID-19 syndrome. In addition, the COVID-19 crisis also worsens behavioral symptoms in uninfected AD patients and poses new challenges for AD prevention. In this review, we first introduce the symptoms and pathogenesis of COVID-19 and AD. Next, we provide a comprehensive discussion on the aggravating effects of AD on COVID-19 and the underlying mechanisms from molecular to social levels. We also highlight the influence of COVID-19 on cognitive function, and propose possible routes of viral invasion into the brain and potential mechanisms underlying the COVID-19-induced cognitive impairment. Last, we summarize the negative impacts of COVID-19 pandemic on uninfected AD patients and dementia prevention.

Preclinical systematic review of ginsenoside Rg1 for cognitive impairment in Alzheimer's disease

Ginseng has been used for the treatment of aging and memory impairment for thousands of years. Several studies have found that ginsenoside Rg1, as one of the main active components of ginseng, could potentially improve cognitive function in several different animal models. A preclinical systematic review to evaluate the efficacy and mechanisms of ginsenoside Rg1 for ameliorating cognitive impairments in Alzheimer's disease is reported here. We searched six databases from their inceptions to January 2019. Thirty-two studies were selected, which included a total of 1,643 animals. According to various cognitive behavioral tests, the results of the meta-analyses showed that ginsenoside Rg1 significantly improved cognitive behavioral impairments in most Alzheimer's disease models (P < 0.05), but there were no significant effects in animals with neuronal degeneration induced by chronic stress or in SAMP8 transgenic mice. The potential mechanisms included antioxidant and anti-inflammatory effects, amelioration of Alzheimer's disease-related pathology, synapse protection, and up-regulation of nerve cells via multiple signaling pathways.

Phytochemical Analysis, In Vitro Anticholinesterase, Antioxidant Activity and In Vivo Nootropic Effect of Ferula ammoniacum (Dorema ammoniacum) D. Don. in Scopolamine-Induced Memory Impairment in Mice

Background: Ferula ammoniacum (D. Don) is one of the endemic medicinal plants that is traditionally used to treat a number of diseases. Although the plant has been used to enhance memory, the investigational evidence supporting the nootropic effect was unsubstantial. Hence, the rationale for this study was to assess the potential beneficial effect of F. ammoniacum seed extracts on learning and memory in mice. Methods: The powdered plant samples (aerial parts) were subjected to extraction ad fractionation. Among the extracts, crude and ethyl acetate extracts were screened for major phytochemicals through HPLC analysis. All the extracts were evaluated for the in vitro anticholinesterase (AChE and BChE) and antioxidant potentials. Among the extracts the active fraction was further assessed for improving learning and memory in mice using behavioural tests like Y-maze and novel object recognition test (NORT) using standard protocols. After behavioural tests, all the animals were sacrificed and brains tissues were assessed for the ex vivo anticholinesterase and antioxidant potentials. Results: Phytochemicals like chlorogenic acid, quercetin, mandelic acid, phloroglucinol, hydroxy benzoic acid, malic acid, epigallocatechin gallate, ellagic acid, rutin, and pyrogallol were identified in crude methanolic extract (Fa.Met) and ethyl acetate fraction (Fa.EtAc) through HPLC. Fa.EtAc and Fa.Chf extracts more potently inhibited AChE and BChE with IC50 values of 40 and 43 µg/mL, and 41 and 42 µg/mL, respectively. Similarly highest free radical scavenging potential was exhibited by Fa.EtAc fraction against DPPH (IC50 = 100 µg/mL) and ABTS (IC50 = 120 µg/mL). The extract doses, 100 and 200 mg/kg body weight significantly (p < 0.01) improved the short-term memory by increasing the percent spontaneous alternation in the Y-maze test along with increasing discrimination index in the NORT that clearly indicated the enhancement in the recognition memory of mice. Conclusion: The extracts more potently scavenged the tested free radicals, exhibited anticholinesterase activities, improved the learning abilities and reduced the memory impairment induced by scopolamine in mice model thus suggesting that these extracts could be effectively used for the management of oxidative stress, neurodegenerative diseases and memory loss.

EGB761 ameliorates chronic cerebral hypoperfusion-induced cognitive dysfunction and synaptic plasticity impairment

Chronic cerebral hypoperfusion (CCH) may lead to the cognitive dysfunction, but the underlying mechanisms are unclear. EGB761, extracted from Ginkgo biloba and as a phytomedicine widely used in the world, has been showed to have various neuroprotective roles and mechanisms, and therapeutic effects in Alzheimer’s disease and other cognitive dysfunctions. However, improvements in cognitive function after CCH, following treatment with EGB761, have not been ascertained yet. In this study, we used the behavior test, electrophysiology, neurobiochemistry, and immunohistochemistry to investigate the EGB761’s effect on CCH-induced cognitive dysfunction and identify its underlying mechanisms. The results showed that EGB761 ameliorates spatial cognitive dysfunction occurring after CCH. It may also improve impairment of the long-term potentiation, field excitable potential, synaptic transmission, and the transmission synchronization of neural circuit signals between the entorhinal cortex and hippocampal CA1. EGB761 may also reverse the inhibition of neural activity and the degeneration of dendritic spines and synaptic structure after CCH; it also prevents the downregulation of synaptic proteins molecules and pathways related to the formation and stability of dendritic spines structures. EGB761 may inhibit axon demyelination and ameliorate the inhibition of the mTOR signaling pathway after CCH to improve protein synthesis. In conclusion, EGB761 treatment after CCH may improve spatial cognitive function by ameliorating synaptic plasticity impairment, synapse degeneration, and axon demyelination by rectifying the inhibition of the mTOR signaling pathway.

Alzheimer's disease treatment: The share of herbal medicines

One of the most frequent forms of dementia in neurological disorders is Alzheimer's disease (AD). It is a chronic neurodegenerative disease characterized by impaired learning and memory. Pathological symptoms as extracellular amyloid-beta (Aβ) plaques and intracellular accumulation of neurofibrillary tangles occur in AD. Due to the aging of the population and increased prevalence of AD, discovery of new therapeutic agents with the highest effectiveness and fewer side effect seems to be necessary. Numerous synthetic medicines such as tacrine, donepezil, galantamine, rivastigmine, memantine, glutathione, ascorbic acid, ubiquinone, ibuprofen, and ladostigil are routinely used for reduction of the symptoms and prevention of disease progression. Nowadays, herbal medicines have attracted popular attention for numerous beneficial effects with little side effects. Lavandula angustifolia, Ginkgo biloba, Melissa officinalis, Crocus sativus, Ginseng, Salvia miltiorrhiza, and Magnolia officinalis have been widely used for relief of symptoms of some neurological disorders. This paper reviews the therapeutic effects of phytomedicines with prominent effects against various factors implicated in the emergence and progression of AD.

Interactions between Ginkgo biloba L. and Scutellaria baicalensis Georgi in multicomponent mixtures towards cholinesterase inhibition and ROS scavenging

This study gives new insights to understand the type of interactions between Ginkgo biloba L. and Scutellaria baicalensis Georgi, two Chinese medicinal plants with well documented neuroprotective effects, on three targets in Alzheimer's disease (AD): acetylcholinesterase (AChE) and butyrylcholnesterase (BuChE) inhibition and hydrogen peroxide scavenging. Individual samples, binary mixtures with different proportions of both plant species, and also a commercial multicomponent combination containing both plants together with unroasted Coffea arabica L. and quercetin-3-O-rutinoside were used to perform this in vitro evaluation. Sample phenolic profiles were also determined by HPLC-DAD, showing the presence of several flavonoid glycosides, phenolic acids and a methylxanthine. In order to investigate the possible synergism/antagonism interaction, data obtained were analyzed by CompuSyn software. The results showed that G. biloba and S. baicalensis alone display better activities than in mixtures, most of the interactions exhibiting different degrees of antagonism. A slight synergism interaction was only observed for the commercial multicomponent mixture tested against H₂O₂. Further analysis was carried out to understand which compounds could be responsible for the antagonistic interaction. Seventeen single pure compounds present in all extracts were tested against AChE inhibition, most of them displaying weak or no activity. Only caffeine had a remarkable activity. Five different binary and quaternary mixture compositions were design to deepen the interaction between these compounds, revealing mainly phenolic acid-flavonoid, flavonoid-flavonoid and methylxanthine-flavonoid-phenolic acid antagonistic interactions. These results clearly show that, for the targets evaluated, there is no potentiation of the neuroprotective effect by combining S. baicalensis and G. biloba extracts.

Network Pharmacology-Based Strategy to Investigate the Pharmacological Mechanisms of Ginkgo biloba Extract for Aging

Aging is a main risk factor for a number of debilitating diseases and contributes to an increase in mortality. Previous studies have shown that Ginkgo biloba extract (EGb) can prevent and treat aging-related diseases, but its pharmacological effects need to be further clarified. This study aimed to propose a network pharmacology-based method to identify the therapeutic pathways of EGb for aging. The active components of EGb and targets of sample chemicals were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database. Information on aging-related genes was obtained from the Human Ageing Genomic Resources database and JenAge Ageing Factor Database. Subsequently, a network containing the interactions between the putative targets of EGb and known therapeutic targets of aging was established, which was used to investigate the pharmacological mechanisms of EGb for aging. A total of 24 active components, 154 targets of active components of EGb, and 308 targets of aging were obtained. Network construction and pathway enrichment were conducted after data integration. The study found that flavonoids (quercetin, luteolin, and kaempferol) and beta-sitosterol may be the main active components of EGb. The top eight candidate targets, namely, PTGS2, PPARG, DPP4, GSK3B, CCNA2, AR, MAPK14, and ESR1, were selected as the main therapeutic targets of EGb. Pathway enrichment results in various pathways were associated with inhibition of oxidative stress, inhibition of inflammation, amelioration of insulin resistance, and regulation of cellular biological processes. Molecular docking results showed that PPARG had better binding capacity with beta-sitosterol, and PTGS2 had better binding capacity with kaempferol and quercetin. The main components of EGb may act on multiple targets, such as PTGS2, PPARG, DPP4, and GSK3B, to regulate multiple pathways, and play an antiaging role by inhibiting oxidative stress, inhibiting inflammation, and ameliorating insulin resistance.

Plasma Tau Variants Detected by a Novel Anti-Tau Monoclonal Antibody: A Potential Biomarker for Alzheimer's Disease

BACKGROUND

A major drawback in Alzheimer's disease (AD) is the lack of validated biomarkers for routine clinical diagnostic. We have reported earlier a novel blood biomarker, named Alz-tau®, based on variants of platelet tau. This marker evaluates the ratio of high molecular weight tau (HMWtau) and the low molecular weight (LMWtau) tau.

OBJECTIVE

To analyze a potential novel source of antigen for Alz-tau®, plasma tau, detected by immunoreactivity with the novel monoclonal antibody, tau51.

METHODS

We evaluated tau variants in plasma precipitated with ammonium sulfate from 36 AD patients and 15 control subjects by western blot with this novel monoclonal antibody.

RESULTS

The HMW/LMWtau ratio was statistically different between AD patients and controls.

CONCLUSIONS

Plasma tau variants are suitable to be considered as a novel antigen source for the Alz-tau® biomarker for AD.

Pharmacogenetic considerations when prescribing cholinesterase inhibitors for the treatment of Alzheimer's disease

INTRODUCTION

Cholinergic dysfunction, demonstrated in the late 1970s and early 1980s, led to the introduction of acetylcholinesterase inhibitors (AChEIs) in 1993 (Tacrine) to enhance cholinergic neurotransmission as the first line of treatment against Alzheimer's disease (AD). The new generation of AChEIs, represented by Donepezil (1996), Galantamine (2001) and Rivastigmine (2002), is the only treatment for AD to date, together with Memantine (2003). AChEIs are not devoid of side-effects and their cost-effectiveness is limited. An option to optimize the correct use of AChEIs is the implementation of pharmacogenetics (PGx) in the clinical practice.

AREAS COVERED

(i) The cholinergic system in AD, (ii) principles of AD PGx, (iii) PGx of Donepezil, Galantamine, Rivastigmine, Huperzine and other treatments, and (iv) practical recommendations.

EXPERT OPINION

The most relevant genes influencing AChEI efficacy and safety are APOE and CYPs. APOE-4 carriers are the worst responders to AChEIs. With the exception of Rivastigmine (UGT2B7, BCHE-K), the other AChEIs are primarily metabolized via CYP2D6, CYP3A4, and UGT enzymes, with involvement of ABC transporters and cholinergic genes (CHAT, ACHE, BCHE, SLC5A7, SLC18A3, CHRNA7) in most ethnic groups. Defective variants may affect the clinical response to AChEIs. PGx geno-phenotyping is highly recommended prior to treatment.

Pharmacological treatment of neuropsychiatric symptoms of dementia: a network meta-analysis protocol

Background

Neuropsychiatric symptoms (NPS) of dementia are a common issue in dementia patients which can lead to poor medical and functional outcomes. Pharmacological interventions are its treatment of choice. However, whether to use pharmacological treatments in this population and which drug should be preferred remain controversial. We therefore aimed to compare and rank pharmacological interventions for NPS according to their efficacy and acceptability profiles by quantifying information from randomized controlled trials (RCTs).

Methods

We will include all RCTs reported as double-blind and comparing one active drug with another or with placebo that compare cholinesterase inhibitors (ChEIs), N-methyl-D-aspartic acid (NMDA) receptor modulators, antipsychotics, antidepressants, and mood stabilisers. Studies will be retrieved by searching electronic databases, including Cochrane Central Register of Controlled Trials, PubMed, MEDLINE, Clinicaltrial.govs, EMBASE, and with no date or language restrictions. The primary outcomes were efficacy (change in overall symptoms) and acceptability (all-cause discontinuation). The network meta-analysis (NMA) will be conducted in R software within a Bayesian framework. The quality of evidence will be evaluated using the Cochrane risk of bias tool, and the GRADE approach. We will conduct subgroup analyses to assess the robustness of our findings.

Results

The results of this study will be published in a peer-reviewed journal.

Conclusions

This systematic review will synthesize the available evidence on the comparative efficacy of different pharmacological approaches in the management of overall NPS, agitation, psychosis, apathy and depressive symptoms in dementia patients. The results of the present NMA will influence evidence-based treatment decisions for clinicians.

Different Doses of Pharmacological Treatments for Mild to Moderate Alzheimer's Disease: A Bayesian Network Meta-Analysis

Background

Pharmacological treatments play a significant role in treating mild to moderate Alzheimer's disease (AD), but the optimal doses of various drugs used for these treatments are unknown. Our study compared the efficacy, acceptability, and safety of different doses of pharmacological treatments for mild to moderate AD.

Methods

Randomized controlled trials (RCTs) were identified by searching the PubMed, EMBASE, and Cochrane Library databases (all RCTs published from the date of inception of the databases until September 19, 2019). Trials comparing the efficacy, acceptability, and safety of pharmacological interventions involving donepezil, galantamine, rivastigmine, memantine, huperzine A, and Ginkgo biloba extract EGb761, alone or in combination, were identified. The primary outcomes were efficacy, acceptability, and safety.

Results

Our meta-analysis included 37 studies involving 14,705 participants. In terms of improving cognitive function, galantamine 32 mg, galantamine 24 mg, donepezil 5 mg, and donepezil 10 mg were more effective than other interventions, with the surface under the cumulative ranking curve (SUCRA) values of 93.2, 75.5, 73.3, and 65.6%, respectively. According to the SUCRA values, EGb761 240 mg was considered to be the optimal intervention in terms of both acceptability and safety. With regard to clinical global impression, rivastigmine 12 mg had the highest probability of being ranked first (83.7%). The rivastigmine 15 cm² patch (SUCRA = 93.7%) may be the best choice for daily living. However, there were no interventions that could significantly improve neuropsychiatric symptoms, compared with the placebo.

Conclusions

Different doses of the tested pharmacological interventions yielded benefits with regard to cognition, acceptability, safety, function, and clinical global impressions, but not effective behaviors.

Current status and future prospects of pathophysiology-based neuroprotective drugs for the treatment of vascular dementia

Vascular dementia (VaD) is a progressive neurocognitive clinical syndrome that is caused by a decrease in cerebral blood flow and damage to the neurovascular unit. Given increasing life expectancy, VaD is emerging as one of the leading health problems in society. Despite the high global prevalence of cognitive impairment associated with VaD, diagnosis and treatment still remain limited because of the complexity of mechanisms of neuronal loss. Therefore, advances in our understanding of the pathophysiological mechanisms involved is crucial for the development of new therapeutic strategies. In this review, we highlight the pathophysiology, current pharmacology-based primary and secondary prevention strategies and emerging treatment options for VaD.