An update on the novel and approved drugs for Alzheimer disease

Exploring Alzheimer's disease treatment: Established therapies and novel strategies for future care

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by a gradual decline in cognitive function, memory impairment, and alterations in behavior. As the predominant etiology of dementia, AD affects millions of individuals worldwide, with its hallmark pathological feature being the accumulation of amyloid beta (Aβ) plaques, which disrupt neuronal function and progressively compromise brain structure. Early clinical manifestations often include forgetfulness, disorientation, and social withdrawal. Primarily impacting the elderly population, AD significantly impairs daily functioning and diminishes overall quality of life. Current therapeutic approaches for AD mainly focus on symptomatic relief and decelerating the disease's progression. Cholinesterase inhibitors, such as donepezil and rivastigmine, increase acetylcholine (ACh) levels to enhance cognitive function in individuals with mild to moderate AD. For individuals in more advanced stages of the disease, NMDA receptor antagonists modulate glutamate activity to mitigate excitotoxicity. In addition to pharmacological interventions, lifestyle modifications such as adherence to a balanced diet, regular physical activity, and cognitive engagement are advocated to support brain health. Novel therapeutic avenues are being explored to address underlying pathophysiological mechanisms, such as metal ion dysregulation within the brain. Furthermore, non-pharmacological approaches, including cognitive-behavioral therapy and patient support groups, provide essential behavioral and emotional support. Cutting-edge research continues to investigate innovative treatments, such as immunotherapies targeting amyloid plaques and tau tangles and neuroprotective compounds derived from natural sources. The goal of these multifaceted strategies is to alleviate symptoms, enhance quality of life, and offer hope for individuals and families affected by AD. This review provides a comprehensive summary of both established and emerging therapeutic interventions for the management of AD.

Neuroprotective effects of Gastrodia elata and its compounds in a Caenorhabditis elegans Alzheimer's disease model

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by learning and memory impairments, primarily caused by excessive β-amyloid protein (Aβ) accumulation, which induces neurotoxicity and metabolic dysfunction. Gastrodia elata (GE), a medicinal herb, has demonstrated antioxidant, antidepressant, and neuroprotective properties, making it a promising candidate for treating neurological diseases. However, systematic studies on its active compounds improving learning and memory through targeted metabolomics remain limited.

PURPOSE

This study aimed to evaluate the neuroprotective effects of Gastrodia elata (GE) and its active compounds, with a specific focus on learning and memory impairments in Alzheimer's disease.

METHODS

Using Caenorhabditis elegans (C. elegans) models of AD, the effects of GE and its active compounds were assessed through chemotaxis assays, targeted metabolomics, and LC-QQQ-MS analysis. Key neurotransmitter levels, including l-Leucine (l-Leu), l-Phenylalanine (l-Phe), γ-aminobutyric acid (GABA), and Acetylcholine (ACh), were quantified. The study also utilized principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) to investigate metabolic biomarkers.

RESULTS

Parishin E (BG E) was identified as the most effective compound in reducing Aβ levels and modulating key biomarkers associated with learning and memory impairments. LC-QQQ-MS analysis showed that BG E restored neurotransmitter levels closer to those of healthy controls. GE extracts (100 μg/ml) and the positive control Huperzine A (Hup A, 8 μg/ml) significantly delayed paralysis in AD C. elegans models. PCA and OPLS-DA analyses confirmed that BG E normalized metabolic biomarkers and key neurotransmitter levels associated with AD.

CONCLUSION

These findings highlight the therapeutic potential of Gastrodia elata, particularly its active compound Parishin E (BG E), in mitigating learning and memory impairments in Alzheimer's disease. This study provides a foundation for further validation in advanced models and supports the development of natural therapeutics for neurological disorders.

A Ginsenoside Composition Ameliorated Aβ and Tau Aggregation via Autophagy Lysosome Pathway

Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by the abnormal deposition of amyloid-beta (Aβ) peptides and neurofibrillary tangles (NFTs). Ginsenosides, the primary active constituents in ginseng, exhibit potential in combating AD. In our previous work, the ginsenoside SumI was demonstrated to have superior anti-AD activity compared to other ginsenosides when used alone. This study revealed that SumI effectively decreased the lysosomal pH, promoted autophagosome formation, increased autophagic flux, and facilitated the transport of misfolded proteins to lysosomes for degradation in Caenorhabditis elegans. SumI activated the HLH-30 transcription factor by triggering a lipid-catabolic response akin to starvation. bec-1 RNAi significantly abrogated the anti-AD effect of SumI. Our findings indicate that SumI mitigated protein aggregation by activating the autophagy-lysosome pathway in C. elegans and provide scientific evidence that ginsenoside composition could be a potential therapeutic agent for treating or preventing AD.

Neuroprotective Potential of Tetraselmis chuii Compounds: Insights into Blood-Brain Barrier Permeability and Intestinal Transport

Background/Objectives: Alzheimer's disease (AD) is the most common type of dementia, characterized by complex processes such as neuro-inflammation, oxidative damage, synaptic loss, and neuronal death. Carotenoids are among the potential therapeutic molecules that have attracted attention due to their neuroprotective properties, but their efficacy is limited mainly by their capacity to cross the blood-brain barrier (BBB). Results: The results showed that T. chuii extracts could protect neuronal cells from neurotoxic damage, especially against L-glutamate and H2O2. Moreover, the BBB permeability and the intestinal transport analyses revealed that fucoxanthinol, crocoxanthin, diatoxanthin, neoxanthin, violaxanthin, and prasinoxanthin have diverse permeabilities depending on the incubation time and the cell model used. Fucoxanthinol was the carotenoid with the highest and similar permeability in HBMEC cells (4.41%, 5.13%, and 18.94% at 2, 4, and 24 h, respectively) and Caco-2 cells (7.01%, 8.63%, and 18.36% at the same times), while crocoxanthin, diatoxanthin, and neoxanthin showed different kinetics. Methods: The neuroprotective potential of two extracts obtained from Tetraselmis chuii microalga were evaluated against Aβ1-42-, L-glutamate-, and H2O2-induced toxicities in SH-SY5Y cells. In addition, the BBB permeability and the intestinal transepithelial transport of the main carotenoids present in the extracts were evaluated and compared using two cell culture models, HBMEC and Caco-2 cells. For that aim, the transport of the bioactive molecules across the barriers was evaluated using UHPLC-q-TOF-MS after 2, 4, and 24 h of incubation. Conclusions: These findings indicate that T. chuii is a promising natural source of bioactive compounds to develop functional foods against neurodegenerative diseases.

Functionalized Nanoparticles: A Promising Approach for Effective Management of Alzheimer's Disease

The severe neurodegenerative disease known as Alzheimer's disease (AD) is typified by a progressive loss of memory and cognitive function. The prevalence of AD is rising due to an aging global population, calling for novel treatment strategies. A potential treatment option for AD that shows promise is the use of functionalized nanoparticles (NPs). Recent developments in the synthesis, design, and use of functionalized NPs in AD therapy are examined in this review. An outline of the pathophysiological mechanisms underlying AD is given in the first section, focusing on the roles played by tau protein aggregates and amyloid-beta plaques in the development of the illness. We then explore the many approaches used to functionalize NPs, such as surface alterations and bioconjugation methods, which enable accurate drug administration, targeted delivery, and enhanced biocompatibility. The review also emphasizes the therapeutic potential of functionalized NPs, highlighting their capacity to improve neuroprotection, lower amyloid-beta aggregation, and improve blood-brain barrier penetration. The potential of NPs as a tool for disease modification and symptom relief is highlighted by recent pre-clinical and clinical research. Concerns about toxicity and safety are also covered, underscoring the significance of thorough testing and the field's future directions. Functionalized NPs have great promise as a multimodal strategy to treat AD, offering patients hope for better quality of life, early diagnosis, and efficient disease treatment. This study highlights the growing role of nanotechnology in the search for novel and potent therapies for AD.

Promising thiazolidinedione-thiazole based multi-target and neuroprotective hybrids for Alzheimer's disease: Design, synthesis, in-vitro, in-vivo and in-silico studies

Alzheimer's disease (AD) is marked by low neurotransmitter levels, inflammation, increased oxidative stress, and the aggregation of amyloid-β and tau proteins. The development of hybrid compounds acting as multi-target-directed ligands (MTDLs) is a novel and contemporary approach in Alzheimer's disease therapeutics. The objective of our current research focuses on identifying compounds with balanced, even moderate inhibition potential against multiple targets associated with cholinergic deficit and neuroinflammation. Inspired by our previous study, the thiazolidinedione-thiazole-based framework has been employed to design and synthesize a series of new hybrids. The inhibitory effects of the synthesized compounds on selected enzymes were investigated by employing in-vitro methods. The synergistic inhibition of acetylcholinesterase (AChE), monoamine oxidase-B (MAO-B), β-secretase (BACE-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) by compound 49 is believed to have a more potent effect in treating Alzheimer's disease. Enzyme kinetic studies and their effect on substrate-enzyme interactions of the compounds with significant inhibitory potency for AChE and MAO-B were also investigated. Central nervous system (CNS) penetration was determined using in-vitro PAMPA assay. A neurotoxicity test on neuroblastoma cell lines (SH-SY5Y) showed that the compounds were non-toxic. Compound 49 showed an excellent neuroprotective effect by significantly reducing H2O2-induced oxidative stress. Antioxidant enzymes were studied in an in-vivo experiment in the brains of male BALB/c mice. Compound 49 showed its ability to reduce the oxidative stress. Furthermore, molecular docking studies and 100 ns MD simulations performed on the AChE, MAO-B, and COX-2 ligand-protein complexes revealed stable conformations of the ligand-protein interactions throughout the simulations.

Virtual screening and molecular dynamics of anti-Alzheimer compounds from Cardiospermum halicacabum via GC-MS

Background

Ayurveda is an ancient Indian medicinal system that uses medicinal plants for their neuroprotective effects. Ayurveda claims that the (C. halicacabum) leaves possess significant neuroprotective properties. Alzheimer's is characterized by the accumulation of amyloid-β, acetylcholinesterase, and tau tangles that interfere with neural transmission and impair cognitive abilities.

Objectives

This study aimed to identify novel potential anti-Alzheimer phytoconstituents of C. halicacabum leaves using in silico methods.

Methods

This study utilized the Box-Behnken design within the response surface methodology (RSM) to optimize and combine the effects of process variables, namely powder weight, solvent volume, and extraction time, on the microwave-assisted extraction (MAE) of C. halicacabum leaves. The optimization process revealed that these variables, along with microwave usage, significantly influenced the extraction yield. The ethanolic extract was examined using gas chromatography-mass spectrometry (GC-MS) analysis, and the identified phytoconstituents were further analyzed through computer-based simulations, including docking, absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies, assessment of drug-likeness, molecular dynamics, LigPlot analysis, and density functional theory (DFT) analysis.

Results

Gas chromatography-mass spectrometry (GC-MS) analysis identified 40 phytoconstituents and 37 were successfully characterized. Molecular docking and dynamics simulations revealed two lead compounds, acetic acid (dodecahydro-7-hydroxy-1,4b,8,8-tetramethyl-10-oxo-2(1H)-phenanthrenylidene)-,2-(dimethylamino)ethyl ester, [1R-(1. alpha)], and 1-(2-hydroxyethoxy)-2-methyldodecane, which exhibited superior stability in the docked complex compared to galantamine.

Conclusion

Based on computational predictions and observed pharmacological properties, these findings suggest that phytoconstituents may have therapeutic effects against selected AD targets.

Bamboo Leaf Flavonoids from Phyllostachys glauca McClure Suppress the Progression of Alzheimer's Disease Induced by Circadian Rhythm Disruption Through Regulating Hif3α/Rab7/TNFα/IL1β Pathway

Circadian rhythm disruption is a modifiable risk factor for Alzheimer's disease (AD) progression, marked by neuroinflammation, oxidative stress, and amyloid-β (Aβ) accumulation. Hypoxia-inducible factor 3α (Hif3α) has emerged as a key regulator of inflammatory and oxidative pathways. To evaluate the impacts of circadian disruption on AD progression and investigate the therapeutic potential of bamboo leaf flavonoids (BLFs), C57BL/6N mice (normal mice) and APP/PS1 transgenic mice (AD mice) were exposed to circadian disruption via randomized light exposure and stress, as the in vivo model. Then, BLFs were administered to assess effects on neuroinflammation, oxidative stress, and organ damage. Next, Nissl body staining and Aβ protein immunohistochemistry were performed to evaluate the effects of BLFs on brain pathology. Through transcriptome sequencing, key factors and the related pathway were screened out. In vitro, molecular mechanisms were explored in PC12 cells treated with Aβ42 and Hif3α siRNA fragments. Results demonstrated that circadian disruption increased oxidative stress and early liver and kidney damage degrees, with greater severity in AD mice. BLFs partially reversed oxidative damage and reduced Aβ deposition. Transcriptome analysis revealed upregulation of Hif3α in circadian-disrupted mice, linked to inflammation and oxidative stress. In vitro, the knockdown of Hif3α reduced inflammation and normalized protein expression, which could be regulated by BLFs and suppressed AD progression. In conclusion, circadian disruption exacerbated AD progression via regulating Hif3α/Rab7/TNFα/IL1β pathway. BLFs offered neuroprotection roles by mitigating inflammation and oxidative damage, highlighting Hif3α as a promising target for AD therapy and biomarker development.

Class balancing diversity multimodal ensemble for Alzheimer's disease diagnosis and early detection

Alzheimer's disease (AD) poses significant global health challenges due to its increasing prevalence and associated societal costs. Early detection and diagnosis of AD are critical for delaying progression and improving patient outcomes. Traditional diagnostic methods and single-modality data often fall short in identifying early-stage AD and distinguishing it from Mild Cognitive Impairment (MCI). This study addresses these challenges by introducing a novel approach: multImodal enseMble via class BALancing diversity for iMbalancEd Data (IMBALMED). IMBALMED integrates multimodal data from the Alzheimer's Disease Neuroimaging Initiative database, including clinical assessments, neuroimaging phenotypes, biospecimen, and subject characteristics data. It employs a new ensemble of model classifiers, designed specifically for this framework, which combines eight distinct families of learning paradigms trained with diverse class balancing techniques to overcome class imbalance and enhance model accuracy. We evaluate IMBALMED on two diagnostic tasks (binary and ternary classification) and four binary early detection tasks (at 12, 24, 36, and 48 months), comparing its performance with state-of-the-art algorithms and an unbalanced dataset method. To further validate the proposed model and ensure genuine generalization to real-world scenarios, we conducted an external validation experiment using data from the most recent phase of the ADNI dataset. IMBALMED demonstrates superior diagnostic accuracy and predictive performance in both binary and ternary classification tasks, significantly improving early detection of MCI at a 48-month time point and showing excellent generalizability in the 12-month task during external validation. The method shows improved classification performance and robustness, offering a promising solution for early detection and management of AD.

Experimental and theoretical studies on structural changes in the microtubule affinity-regulating kinase 4 (MARK4) protein induced by N-hetarenes: a new class of therapeutic candidates for Alzheimer's disease

Introduction

Alzheimer's disease (AD) is a neurodegenerative disorder that progressively affects the cognitive function and memory of the affected person. Unfortunately, only a handful of effective prevention or treatment options are available today. Microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine protein that plays a critical role in regulating microtubule dynamics and facilitating cell division. The dysregulated expression of MARK4 has been associated with a range of diseases, including AD.

Methods

In this study, we synthesized a series of N-hetarenes via Pd(0)-catalyzed Suzuki-Miyaura cross coupling reaction. All compounds were characterized using multi-spectroscopic techniques and evaluated for their activity against the MARK4 enzyme through ATPase inhibition assays. The experimental data was further supported by computational and quantum chemical calculations. We also computed the drug-likeness, bioavailability, and toxicity (ADME/T) profiles of the compounds.

Results

Six new 4-(6-(arylpyrimidin-4-yl)piperazine-1-carboximidamides 5-10 were prepared in good yields. ATPase inhibition assay conducted on these compounds demonstrated IC50 values in micromolar range (5.35 ± 0.22 to 16.53 ± 1.71 μM). Among the tested compounds, 4-(6-(p-tolyl)pyrimidin-4-yl)piperazine-1-carboximidamide (5; IC50 = 5.35 ± 0.22 μM) and 4-(6-(benzo[b]thiophen-2-yl)pyrimidin-4-yl)piperazine-1-carboximidamide (9; IC50 = 6.68 ± 0.80 μM) showed the best activity. The binding constant (K), as determined by the fluorescence quenching assay was estimated to be 1.5 ± 0.51 × 105 M-1 for 5 and 1.14 ± 0.26 × 105 M-1 for 9. The results of molecular docking and MD simulation studies against MARK4 (PDB: 5ES1) indicated that compounds were able to bind the ATP binding pocket of the MARK4, leading to its stabilization. Additionally, ADME/T analysis revealed a high degree of drug-likeness of the compounds.

Conclusion

We demonstrated that 4-(6-(arylpyrimidin-4-yl)piperazine-1-carboximidamides) are a promising class of N-hetarenes for developing next-generation anti-AD drugs. The reported class of compounds inhibited MARK4 activity in-vitro at micromolar concentration by targeting the ATP-binding pocket. These findings provide valuable insights for future drug design.

Kaempferia parviflora extract and its methoxyflavones as potential anti-Alzheimer assessing in vitro, integrated computational approach, and in vivo impact on behaviour in scopolamine-induced amnesic mice

Alzheimer's disease (AD), a growing global challenge, lacks effective preventive and therapeutic strategies. This study explored the promising potential of the Kaempferia parviflora (KP) and its methoxyflavones (MFs) against the disease. We evaluated KP extract and its five MFs for antioxidant capacity, cholinesterase inhibition (AChE, and BChE), amyloid plaque (Aβ) reduction, neuroprotection, and memory improvement in a mouse model. HPLC quantified the five MFs in KP extract, with 5,7-dimethoxyflavone (F1) being the most abundant. 5,7,4'-Trimethoxyflavone (F3) and 5-hydroxy-3,7-dimethoxyflavone (F4) exhibited the strongest AChE and BChE inhibitory activities, respectively. MFs hindered Aβ1-42 aggregation and destabilized fibrils, with F3 showing the potent anti-aggregation and the strongest fibril destabilization. They also protected SH-SY5Y cells from Aβ1-42-induced damage. Notably, F3 combined anti-cholinesterase and anti-Aβ activities, suggesting its potential as a multi-target agent. KP extract ameliorated scopolamine-induced memory deficits in mice, suggesting its potential for cognitive improvement. These findings revealed that KP can be a promising candidate for herbal medicine development against AD. Its multi-target MFs offered a unique advantage by targeting multiple AD pathways. KP may have a great potential to modify the disease and overcome the challenge of drug development as cognitive enhancing herbal medicine.

In Silico and In Vitro Evaluation of Quinoline Derivatives as Potential Inhibitors of AChE, BACE1, and GSK3β for Neurodegenerative Diseases Treatment

Neurodegenerative diseases are characterized by the structural and functional loss of neurons, which impacts populations worldwide. Enzymes such as acetylcholinesterase (AChE), beta-site APP cleaving enzyme-1 (BACE1), and glycogen synthase kinase 3-beta (GSK3β) are implicated in their progression. Therefore, developing compounds that inhibit these enzymes is relevant for treating these conditions. This study investigated the potential of quinoline analogs as multitarget enzyme inhibitors through in silico and in vitro assays. In silico analyses highlighted one of the derivatives as the most potent inhibitor for all proteins. In vitro assays confirmed that the quinoline derivatives modulated the activity of the three targets. The best derivative in silico also exhibited significant AChE inhibition of 94.6 %. For GSK3β and BACE1, four derivatives, with quinoline linked to the sulfonamide nitrogen, showed inhibition values above 40 %. Two of them demonstrated no cytotoxicity for human glioblastoma cell proliferation, and the most potent was noncytotoxic at 7.8 and 3.9 μg mL-1. In murine fibroblasts, the most potent derivative showed no cytotoxicity, unlike its effect on glioblastoma cells. Similarly, other derivatives were noncytotoxic at concentrations less than 62.5 μg mL-1. These findings highlight one of the derivatives as promising multitarget enzyme inhibitors for the treatment of neurodegenerative diseases.

Cholinesterase Inhibitors from Plants and Their Potential in Alzheimer's Treatment: Systematic Review

INTRODUCTION

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by memory loss and cognitive decline, primarily due to dysfunction of acetylcholine caused by acetylcholinesterase and butyrylcholinesterase. While synthetic cholinesterase inhibitors like donepezil, rivastigmine, and galantamine are commonly used, they have notable side effects, prompting interest in natural alternatives. Medicinal plants, rich in bioactive compounds like flavonoids and alkaloids, have shown potential as cholinesterase inhibitors with additional antioxidants and anti-inflammatory benefits. This study aimed to evaluate the cholinesterase-inhibiting effects of various plant species and their compounds to identify new therapeutic candidates and reduce side effects.

METHOD

A PRISMA-compliant review was conducted, screening studies from multiple databases, with a final inclusion of 64 in vivo studies.

RESULTS

These studies highlighted plant extracts such as Ferula ammoniacum, Elaeagnus umbellata, Bacopa monnieri, and Centella asiatica, which improved memory, reduced oxidative stress, and provided neuroprotection. Some extracts also reduced amyloid plaques, enhanced neuronal integrity, and restored cholinesterase activity, indicating their potential as therapeutic agents for AD and other neurodegenerative diseases.

CONCLUSIONS

The findings underscore the promise of plant-based compounds in treating cognitive decline and cholinergic dysfunction in AD, advocating for further research into their therapeutic potential.

Newer Therapeutic Approaches in Treating Alzheimer's Disease: A Comprehensive Review

Alzheimer's disease (AD) is an aging-related irreversible neurodegenerative disease affecting mostly the elderly population. The main pathological features of AD are the extracellular Aβ plaques generated by APP cleavage through the amyloidogenic pathway, the intracellular neurofibrillary tangles (NFT) resulting from the hyperphosphorylated tau proteins, and cholinergic neurodegeneration. However, the actual causes of AD are unknown, but several studies suggest hereditary mutations in PSEN1 and -2, APOE4, APP, and the TAU genes are the major perpetrators. In order to understand the etiology and pathogenesis of AD, various hypotheses are proposed. These include the following hypotheses: amyloid accumulation, tauopathy, inflammation, oxidative stress, mitochondrial dysfunction, glutamate/excitotoxicity, cholinergic deficiency, and gut dysbiosis. Currently approved therapeutic interventions are donepezil, galantamine, and rivastigmine, which are cholinesterase inhibitors (ChEIs), and memantine, which is an N-methyl-d-aspartate (NMDA) antagonist. These treatment strategies focus on only symptomatic management of AD by attenuating symptoms but not regeneration of neurons or clearance of Aβ plaques and hyperphosphorylated Tau. This review focuses on the pathophysiology, novel therapeutic targets, and disease-altering treatments such as α-secretase modulators, active immunotherapy, passive immunotherapy, natural antioxidant products, nanomaterials, antiamyloid therapy, tau aggregation inhibitors, transplantation of fecal microbiota or stem cells, and microtubule stabilizers that are in clinical trials or still under investigation.

Therapeutic Role of Heterocyclic Compounds in Neurodegenerative Diseases: Insights from Alzheimer's and Parkinson's Diseases

Alzheimer's and Parkinson's are the most common neurodegenerative diseases (NDDs). The development of aberrant protein aggregates and the progressive and permanent loss of neurons are the major characteristic features of these disorders. Although the precise mechanisms causing Alzheimer's disease (AD) and Parkinson's disease (PD) are still unknown, there is a wealth of evidence suggesting that misfolded proteins, accumulation of misfolded proteins, dysfunction of neuroreceptors and mitochondria, dysregulation of enzymes, and the release of neurotransmitters significantly influence the pathophysiology of these diseases. There is no effective protective medicine or therapy available even with the availability of numerous medications. There is an urgent need to create new and powerful bioactive compounds since the number of people with NDDs is rising globally. Heterocyclic compounds have consistently played a pivotal role in drug discovery due to their exceptional pharmaceutical properties. Many clinically approved drugs, such as galantamine hydrobromide, donepezil hydrochloride, memantine hydrochloride, and opicapone, feature heterocyclic cores. As these heterocyclic compounds have exceptional therapeutic potential, heterocycles are an intriguing research topic for the development of new effective therapeutic drugs for PD and AD. This review aims to provide current insights into the development and potential use of heterocyclic compounds targeting diverse therapeutic targets to manage and potentially treat patients with AD and PD.

Stabilization of mitochondria-associated endoplasmic reticulum membranes regulates Aβ generation in a three-dimensional neural model of Alzheimer's disease

INTRODUCTION

We previously demonstrated that regulating mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) affects axonal Aβ generation in a well-characterized three-dimensional (3D) neural Alzheimer's disease (AD) model. MAMs vary in thickness and length, impacting their functions. Here, we examined the effect of MAM thickness on Aβ in our 3D neural model of AD.

METHODS

We employed fluorescence resonance energy transfer (FRET) or fluorescence-based MAM stabilizers, electron microscopy, Aβ enzyme-linked immunosorbent assay (ELISA), and live-cell imaging with kymography to assess how stabilizing MAMs of different gap widths influence Aβ production and MAM axonal mobility.

RESULTS

Stabilizing tight MAMs (∼6 nm gap width) significantly increased Aβ levels, whereas basal (∼25 nm) and loose MAMs (∼40 nm) maintained or reduced Aβ levels, respectively. Tight MAMs reduced mitochondrial axonal velocity compared to basal MAMs, while loose MAMs showed severely reduced axonal distribution.

DISCUSSION

Our findings suggest that stabilizing MAMs of specific gap widths, particularly in axons, without complete destabilization could be an effective therapeutic strategy for AD.

HIGHLIGHTS

The stabilization of MAMs exacerbates or ameliorates Aβ generation from AD neurons in a MAM gap width-dependent manner. A specific stabilization threshold within the MAM gap width spectrum shifts the amyloidogenic process to non-amyloidogenic. Tight MAMs slow down mitochondrial axonal transport compared to lose MAMs offering a quantitative method for measuring MAM stabilization.

Emerging advances in nano-biomaterial assisted amyloid beta chimeric antigen receptor macrophages (CAR-M) therapy: reducing plaque burden in Alzheimer's disease

Alzheimer's disease is the most common form, accounting for 60-70% of 55 million dementia cases. Even though the precise pathophysiology of AD is not completely understood, clinical trials focused on antibodies targeting aggregated forms of β amyloid (Aβ) have demonstrated that reducing amyloid plaques can arrest cognitive decline in patients in the early stages of AD. In this study, we provide an overview of current research and innovations for controlled release from nano-biomaterial-assisted chimeric antigen receptor macrophage (CAR-M) therapeutic strategies targeted at AD. Nano-bio materials, such as iron-oxide nanoparticles (IONPs), can be made selectively (Hp-Hb/mannose) to bind and take up Aβ plaques like CAR-M cells. By using nano-bio materials, both the delivery and stability of CAR-M cells in brain tissue can be improved to overcome the barriers of the BBB and enhance therapeutic effects. By enhancing the targeting capabilities and stability of CAR-M cells, mRNA-loaded nano-biomaterials can significantly improve the efficacy of immunotherapy for plaque reduction in AD. This novel strategy holds promise for translating preclinical successes into clinical applications, potentially revolutionising the management of AD.

Drugs repurposing in the experimental models of Alzheimer's disease

The currently approved drugs for Alzheimer's disease (AD) are only for symptomatic treatment in the early stages of the disease but they could not halt the neurodegeneration, additionally, the safety profile of the recently developed immunotherapy is a big issue. This review aims to explain the importance of the drugs repurposing technique and strategy to develop therapy for AD. We illustrated the biological alterations in the pathophysiology of AD including the amyloid pathology, the Tau pathology, oxidative stress, mitochondrial dysfunction, neuroinflammation, glutamate-mediated excitotoxicity, insulin signaling impairment, wingless-related integration site/β-catenin signaling, and autophagy. Additionally, we demonstrated the different repurposed drugs in the experimental models of AD including the anti-inflammatory, anti-hypertensive, anti-diabetic, antiepileptic, antidepressant and anticancer drugs. Further, we showed the pipeline and FDA approved drugs for AD. The repurposed drugs have a promising therapeutic activity against AD, confirming the value of the drugs repurposing technique to elucidate curative therapy for AD.

Sodium Thiosulfate: An Innovative Multi-Target Repurposed Treatment Strategy for Late-Onset Alzheimer's Disease

Late-onset Alzheimer's disease (LOAD) is a chronic, multifactorial, and progressive neurodegenerative disease that associates with aging and is highly prevalent in our older population (≥65 years of age). This hypothesis generating this narrative review will examine the important role for the use of sodium thiosulfate (STS) as a possible multi-targeting treatment option for LOAD. Sulfur is widely available in our environment and is responsible for forming organosulfur compounds that are known to be associated with a wide range of biological activities in the brain. STS is known to have (i) antioxidant and (ii) anti-inflammatory properties; (iii) chelation properties for calcium and the pro-oxidative cation metals such as iron and copper; (iv) donor properties for hydrogen sulfide production; (v) possible restorative properties for brain endothelial-cell-derived bioavailable nitric oxide. Thus, it becomes apparent that STS has the potential for neuroprotection and neuromodulation and may allow for an attenuation of the progressive nature of neurodegeneration and impaired cognition in LOAD. STS has been successfully used to prevent cisplatin oxidative-stress-induced ototoxicity in the treatment of head and neck and solid cancers, cyanide and arsenic poisoning, and fungal skin diseases. Most recently, intravenous STS has become part of the treatment plan for calciphylaxis globally due to vascular calcification and ischemia-induced skin necrosis and ulceration. Side effects have been minimal with reports of metabolic acidosis and increased anion gap; as with any drug treatment, there is also the possibility of allergic reactions, possible long-term osteoporosis from animal studies to date, and minor side-effects of nausea, headache, and rhinorrhea if infused too rapidly. While STS poorly penetrates the intact blood-brain barrier(s) (BBBs), it could readily penetrate BBBs that are dysfunctional and disrupted to deliver its neuroprotective and neuromodulating effects in addition to its ability to penetrate the blood-cerebrospinal fluid barrier of the choroid plexus. Novel strategies such as the future use of nano-technology may be helpful in allowing an increased entry of STS into the brain.

A Narrative Review on the Neuroprotective Potential of Brown Macroalgae in Alzheimer's Disease

Systematic Alzheimer's disease (AD) is a neurodegenerative disease increasingly prevalent in the aging population. AD is characterized by pathological features such as β-amyloid (Aβ) plaque accumulation, tau neurofibrillary tangles formation, oxidative stress, an impaired cholinergic system, and neuroinflammation. Many therapeutic drugs have been developed to slow the progression of AD by targeting these pathological mechanisms. However, synthetic drugs, such as donepezil and memantine, can often lead to side effects. In this context, seaweeds have been drawing attention as a nutrient source and a potential source of health-improving metabolites. Studies have shown that extracts from brown macroalgae can potentially reduce the inflammation associated with neurodegenerative diseases by inhibiting proinflammatory cytokine expression. Furthermore, their bioactive compounds exhibit antioxidant properties vital in combating oxidative stress. Antioxidants, mainly carotenoids and phenolic compounds, have been linked to improved cognitive function and a reduced risk of neurodegenerative disorders by protecting neuronal cells through their ability to scavenge free radicals. In addition, omega-3 fatty acids found in certain macroalgae have the potential to support brain health and cognitive function, further enhancing their neuroprotective effects. In conclusion, this review has comprehensively evaluated the research conducted on brown macroalgae in the last five years, covering their potential bioactive compounds, methods of obtaining these compounds, and their neuroprotective properties against AD. The limited number of clinical studies in the literature highlights the need for further research. This narrative review provides a basic framework for new approaches to neuroprotective strategies, such as those associated with brown macroalgae natural resources. Furthermore, they may play an increasingly important role in developing functional foods and nutraceuticals that can support human health in preventing and managing neurodegenerative diseases.

Sulfonamido, amido heterocyclic adducts of tetrazole derivatives as BACE1 inhibitors: in silico exploration

Alzheimer's disease is a neurodegenerative disorder accounting for 60-80% of dementia cases and is accompanied by a high mortality rate in patients above 70 years of age. The formation of senile plaques composed of amyloid-β protein is a hallmark of Alzheimer's disease. Beta-site APP cleaving enzyme 1 (BACE1) is a proteolytic enzyme involved in the degradation of amyloid precursor protein, which further degrades to form toxic amyloid-β fragments. Hence, inhibition of BACE1 was stated to be an effective strategy for Alzheimer's therapeutics. Keeping in mind the structures of different BACE1 inhibitors that had reached the clinical trials, we designed a library of compounds (total 164) based on a substituted 5-amino tetrazole scaffold which was an isosteric replacement of the cyclic amidine moiety, a common component of the BACE1 inhibitors which reached the clinical trials. The scaffold was linked to different structural moieties with the aid of an amide or sulfonamide bond to design some novel molecules. Molecular docking was initially performed and the top 5 molecules were selected based on docking scores and protein-ligand interactions. Furthermore, molecular dynamic simulations were performed for these molecules (3g, 7k, 8n, 9d, 9g) for 100 ns and MM-GBSA calculations were performed for each of these complexes. After critical evaluation of the obtained results, three potential molecules (9d, 8n, and 7k) were forwarded for prolonged stability studies by performing molecular dynamic simulations for 250 ns and simultaneous MM-GBSA calculations. It was observed that the compounds (9d, 8n, and 7k) were forming good interactions with the amino acid residues of the catalytic site of the enzyme with multiple non-covalent interactions. In MD simulations, the compounds have shown better stability and better binding energy throughout the runtime.

MAD-microbial (origin of) Alzheimer's disease hypothesis: from infection and the antimicrobial response to disruption of key copper-based systems

Microbes have been suspected to cause Alzheimer's disease since at least 1908, but this has generally remained unpopular in comparison to the amyloid hypothesis and the dominance of Aβ and Tau. However, evidence has been accumulating to suggest that these earlier theories are but a manifestation of a common cause that can trigger and interact with all the major molecular players recognized in AD. Aβ, Tau and ApoE, in particular appear to be molecules with normal homeostatic functions but also with alternative antimicrobial functions. Their alternative functions confer the non-immune specialized neuron with some innate intracellular defenses that appear to be re-appropriated from their normal functions in times of need. Indeed, signs of infection of the neurons by biofilm-forming microbial colonies, in synergy with herpes viruses, are evident from the clinical and preclinical studies we discuss. Furthermore, we attempt to provide a mechanistic understanding of the AD landscape by discussing the antimicrobial effect of Aβ, Tau and ApoE and Lactoferrin in AD, and a possible mechanistic link with deficiency of vital copper-based systems. In particular, we focus on mitochondrial oxidative respiration via complex 4 and ceruloplasmin for iron homeostasis, and how this is similar and possibly central to neurodegenerative diseases in general. In the case of AD, we provide evidence for the microbial Alzheimer's disease (MAD) theory, namely that AD could in fact be caused by a long-term microbial exposure or even long-term infection of the neurons themselves that results in a costly prolonged antimicrobial response that disrupts copper-based systems that govern neurotransmission, iron homeostasis and respiration. Finally, we discuss potential treatment modalities based on this holistic understanding of AD that incorporates the many separate and seemingly conflicting theories. If the MAD theory is correct, then the reduction of microbial exposure through use of broad antimicrobial and anti-inflammatory treatments could potentially alleviate AD although this requires further clinical investigation.

In-vitro Neuro-2a cytotoxicity analysis and molecular docking investigation on potential anti-amyloid agents from Adiantum lunulatum

In neurodegenerative diseases, amyloid formation by some proteins cause neuronal damage and loss. To prevent this neuronal damage and loss certain pharmaceuticals are available. Many of these pharmaceuticals act on the neurodegenerative disease symptoms but not on the root cause. This study helps to detect more effective agents which directly act on the root cause and reduce the risk of neurodegenerative diseases. To identify new anti-amyloid agents, the folk medicinally important plant Adiantum lunulatum was collected, authenticated, dried, extracted with ethanol and analyzed by GC-MS method. The screening of the identified phytochemicals was done using the webservers swissADME and ProTox-II. In-vitro MTT assay using Neuro-2a cell lines was carried out to determine the cytotoxicity of the extract. The interactions of these phytochemicals with the amyloid forming peptides and proteins were predicted using the molecular docking tools such as AutoDock Vina and BIOVIA discovery studio visualizer 2020. Through GC-MS analysis, 18 different volatile phytochemicals were identified from the ethanol extract. From this, 7 phytochemicals were selected based on the computational non-toxicity prediction. In-vitro cytotoxicity analysis of the ethanol extract using Neuro-2a cell lines detected the IC50 value of 0.09 mg/ml. Of these, the phytochemical P1 (trans, trans-9, 12-Octadecadienoic acid, propyl ester) interacts with tau, and huntingtin proteins, P2 (2-Pentadecanone, 6, 10, 14-trimethyl-) interacts with prion protein. The phytochemicals P1, P3 (Ethyl oleate), P4 (Octadecanoic acid, ethyl ester), and P5 (Phytol) interact with acetylcholinesterase. P2, P4, P5 and P6 (Henicosanal), interact with BACE-1. The phytochemical P3 interacts with γ- Secretase. The interaction of P2 and P5 with BACE-1 and P3 with γ- Secretase show better inhibition in inhibitory constant (K i ) analysis. These phytochemicals have been predicted to show significant potential against the formation or breakdown of peptide/protein amyloids, and further in-vitro studies are necessary to develop them into anti-amyloid agents.

Mannich reaction mediated derivatization of chromones and their biological evaluations as putative multipotent ligands for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is a complex neurological disorder and multiple pathways are associated with its pathology. Currently available single-targeting drugs are found to be ineffective for the treatment of AD, and most of these drugs provide symptomatic relief. The multi-target directed ligand strategy is proposed as an effective approach for the treatment of AD. Herein, we report the design and synthesis of a series of 2-phenyl substituted chromone derivatives and their evaluation against AChE, MAO-B, and β amyloid self-aggregation inhibition. In the series, NS-4 and NS-13 were identified as the potent leads against all the specified targets. NS-4 and NS-13 exhibited balanced multipotent activities against AChE with IC50 values of 3.09 μM, and 0.625 μM and against MAO-B with IC50 values of 19.64 μM and 12.31 μM, respectively. These compounds also displayed 28.5% and 32.2% self-aggregation inhibition potential against Aβ1-42, respectively. All the compounds were found to be selective for AChE over BuChE. Additionally, NS-4 also exhibited potent BuChE inhibition with an IC50 value of 1.95 μM. Moreover, NS-4 and NS-13 reduced intracellular ROS levels up to 65% against SH-SY5Y cells at 25 μM concentration. The lead compounds were found to be neuroprotective and exhibited no cytotoxicity even at 25 μM concentration. In enzyme kinetic inhibition studies, these compounds showed mixed-type inhibition to AChE. In the computational studies, binding interactions, and orientations of the ligands at the active site of the enzymes were analyzed and these lead compounds were found to be thermodynamically stable inside the active cavity for up to 100 ns.

Mesenchymal stem cell therapy for Alzheimer's disease: A novel therapeutic approach for neurodegenerative diseases

Alzheimer's disease (AD) is one of the most progressive and prevalent types of neurodegenerative diseases in the aging population (aged >65 years) and is considered a major factor for dementia, affecting 55 million people worldwide. In the current scenario, drug-based therapies have been employed for the treatment of Alzheimer's disease but are only able to provide symptomatic relief to patients rather than a permanent solution from Alzheimer's. Recent advancements in stem cell research unlock new horizons for developing effective and highly potential therapeutic approaches due to their self-renewal, self-replicating, regenerative, and high differentiation capabilities. Stem cells come in multiple lineages such as embryonic, neural, and induced pluripotent, among others. Among different kinds of stem cells, mesenchymal stem cells are the most investigated for Alzheimer's treatment due to their multipotent nature, low immunogenicity, ability to penetrate the blood-brain barrier, and low risk of tumorigenesis, immune & inflammatory modulation, etc. They have been seen to substantially promote neurogenesis, synaptogenesis by secreting neurotrophic growth factors, as well as in ameliorating the Aβ and tau-mediated toxicity. This review covers the pathophysiology of AD, new medications, and therapies. Further, it will focus on the advancements and benefits of Mesenchymal Stem Cell therapies, their administration methods, clinical trials concerning AD progression, along with their future prospective.

Exploring the therapeutic potential of steroidal alkaloids in managing Alzheimer's disease

Steroidal alkaloids are secondary metabolites that are often found in plants, fungi and sponges. These compounds are considered as a source of bioactive compounds for the treatment of chronic diseases, such as neurological disorder like Alzheimer's disease (AD). Some examples of alkaloid derivatives currently used to treat AD symptoms include galantamine, huperzine A, and other alkaloids. AD is a multifactorial disease caused by multiple factors such as inflammation, oxidative stress, and protein aggregation. Based on the various important neuroprotective activities and different pharmacological effects of steroidal alkaloids with polypharmacological modulatory effects, they can lead to the development of new drugs for the treatment of AD. There are limited studies on the involvement of steroidal alkaloids in AD. Therefore, the mechanisms and neuroprotective abilities of these compounds are still poorly understood. The purpose of this review article is to provide an overview of the mechanism, toxicity and neuroprotective benefits of steroidal alkaloids and to discuss future possibilities to improve the application of steroidal alkaloids as anti-AD agents. The therapeutic value and limitations of the steroidal alkaloid are investigated to provide new perspectives for future clinical development studies.

Mutation of TRPML1 Channel and Pathogenesis of Neurodegeneration in Haimeria

Neurodegenerative diseases, a group of debilitating disorders, have garnered increasing attention due to their escalating prevalence, particularly among aging populations. Alzheimer's disease (AD) reigns as a prominent exemplar within this category, distinguished by its relentless progression of cognitive impairment and the accumulation of aberrant protein aggregates within the intricate landscape of the brain. While the intricate pathogenesis of neurodegenerative diseases has been the subject of extensive investigation, recent scientific inquiry has unveiled a novel player in this complex scenario-transient receptor potential mucolipin 1 (TRPML1) channels. This comprehensive review embarks on an exploration of the intricate interplay between TRPML1 channels and neurodegenerative diseases, with an explicit spotlight on Alzheimer's disease. It immerses itself in the intricate molecular mechanisms governing TRPML1 channel functionality and elucidates their profound implications for the well-being of neurons. Furthermore, the review ventures into the realm of therapeutic potential, pondering the possibilities and challenges associated with targeting TRPML1 channels as a promising avenue for the amelioration of neurodegenerative disorders. As we traverse this multifaceted terrain of neurodegeneration and the enigmatic role of TRPML1 channels, we embark on a journey that not only broadens our understanding of the intricate machinery governing neuronal health but also holds promise for the development of innovative therapeutic interventions in the relentless battle against neurodegenerative diseases.

Profiling of microglial-originated microvesicles to unearthing their lurking potential as potent foreseeable biomarkers for the diagnosis of Alzheimer's disease: A systematic review

BACKGROUND

Alzheimer's Disease is a neurodegenerative disease characterized by accumulation of phosphorylated tau and amyloid deposits within the brain tissues in the elderly population. Numerous studies established that amassment of these toxic accretions within the brain tissues initiates neuronal demise and synaptic impairment which becomes the underlying basis for memory loss and cognitive abnormalities in these patients.

HYPOTHESIS

Hypoxia, oxidative stress, and inflammation are commonly encountered perils in the neuronal milieu that derail the neuron-synapse interactions and maneuver them to undergo apoptosis. A spinoff from neuronal desecration is microglial activation which forms a cardinal role in mounting innate immune defenses for warding off and reversing off toxic stimulus encountered.

RESULTS

A potential ramification of microglial activation in this context is assembly, processing and exuding of micro-vesicles into the extracellular space. These micro-vesicles will be packaged with amyloid and tau deposits which accumulate intracellularly within microglial cells secondary to their professional scavenging function. These microglial MVs are prone to seed tau and amyloid beta into the surrounding neuron-synapse framework, thus are implicated in spreading the disease pathology in AD.

CONCLUSIONS

Therefore, these MVs can be considered as an omen for disease initiation, progression, monitoring as well gauging the treatment response in the clinical AD cohorts. We speculate future research studies to unmask the dormant potential of these microglial MVs as reliable markers for diagnosis, evaluating the disease progression as well as treatment in AD. This will open the door for early diagnosis of AD so as to prioritize management and optimize clinical outcomes..

Research Progress on the Pathogenesis, Diagnosis, and Drug Therapy of Alzheimer's Disease

As the population ages worldwide, Alzheimer's disease (AD), the most prevalent kind of neurodegenerative disorder among older people, has become a significant factor affecting quality of life, public health, and economies. However, the exact pathogenesis of Alzheimer's remains elusive, and existing highly recognized pathogenesis includes the amyloid cascade hypothesis, Tau neurofibrillary tangles hypothesis, and neuroinflammation hypothesis. The major diagnoses of Alzheimer's disease include neuroimaging positron emission computed tomography, magnetic resonance imaging, and cerebrospinal fluid molecular diagnosis. The therapy of Alzheimer's disease primarily relies on drugs, and the approved drugs on the market include acetylcholinesterase drugs, glutamate receptor antagonists, and amyloid-β monoclonal antibodies. Still, the existing drugs can only alleviate the symptoms of the disease and cannot completely reverse it. This review aims to summarize existing research results on Alzheimer's disease pathogenesis, diagnosis, and drug therapy, with the objective of facilitating future research in this area.

The donepezil transdermal system for the treatment of patients with mild, moderate, or severe Alzheimer's disease: a critical review

INTRODUCTION

Cholinesterase inhibitors, along with memantine, are the mainstay of symptomatic treatment for AD (Alzheimer's disease); however, these medications are typically administered orally, which can be difficult for people with AD and their caregivers.

AREAS COVERED

In this drug profile and narrative review, the authors trace the development of the new FDA-approved transdermal donepezil. The authors discuss the studies showing its bioequivalence with the oral formulation, including two double-blinded placebo controlled non-inferiority trials. The authors also compare the patch to the only other transdermal cholinesterase inhibitor on the market, rivastigmine, and highlight the potential advantages and disadvantages between these two treatments.

EXPERT OPINION

While the patch is bio-equivalent, it is rather large and may not be affordable for some patients. In addition, there is no high dose (e.g. 23 mg) equivalent. Nevertheless, transdermal donepezil will be useful for people with AD and their caregivers, given its effectiveness and potential convenience.

Harnessing the potential of mesenchymal stem cells-derived exosomes in degenerative diseases

Mesenchymal stem cells (MSCs) have gained attention as a promising therapeutic approach in both preclinical and clinical osteoarthritis (OA) settings. Various joint cell types, such as chondrocytes, synovial fibroblasts, osteoblasts, and tenocytes, can produce and release extracellular vesicles (EVs), which subsequently influence the biological activities of recipient cells. Recently, extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have shown the potential to modulate various physiological and pathological processes through the modulation of cellular differentiation, immune responses, and tissue repair. This review explores the roles and therapeutic potential of MSC-EVs in OA and rheumatoid arthritis, cardiovascular disease, age-related macular degeneration, Alzheimer's disease, and other degenerative diseases. Notably, we provide a comprehensive summary of exosome biogenesis, microRNA composition, mechanisms of intercellular transfer, and their evolving role in the highlight of exosome-based treatments in both preclinical and clinical avenues.

Effectiveness of epigallocatechin gallate nanoparticles on the in-vivo treatment of Alzheimer's disease in a rat/mouse model: a systematic review

BACKGROUND

Alzheimer's disease (AD) is a neurological disease that causes memory loss over time. Current therapies are limited and frequently inadequate. Epigallocatechin gallate (EGCG), has antioxidant, anti-inflammatory, antifibrosis, anti-remodeling and tissue-protective qualities that may be effective in treatment of different diseases, including AD. Because of nanoparticles' high surface area, they can enhance solubility, stability, pharmacokinetics and biodistribution, and diminish toxicities. Besides, lipid nanoparticles have a high binding affinity that can enhance the rate of drug transport across BBB. So, EGCG nanoparticles represent a promising treatment for AD.

OBJECTIVES

This systematic review sought to assess the efficacy of EGCG nanoparticles against AD in rat/mouse models.

METHODS

Study was conducted in accordance with PRISMA guidelines, and the protocol was registered in PROSPERO. Electronic databases were searched to discover relevant studies published up to October 2022.

RESULTS

Two studies met the inclusion criteria out of 1338 and were included in this systematic review. Collectively, the results indicate that EGCG has a significant potential for reducing AD pathology and improving cognitive deficits in rat/mouse models. The formulated particles were in the nanometer range, as indicated by TEM, with good particle size control and stability. EGCG nanoparticles showed superior pharmacokinetic characteristics and improved blood-brain barrier permeability, and increased brain bioavailability compared to free EGCG. Additionally, nanoEGCG were more effective in modulating oxidative stress than free formulation and decreased AChE in the cortex and hippocampus of AlCl3-treated rats.

CONCLUSION

This systematic analysis of the two studies included showed that EGCG nanoparticles are efficacious as a potential therapeutic intervention for AD in rat/mouse models. However, limited number of studies found indicates insufficient data in this research point that requires further investigation by experimental studies.

Research progress of PROTACs for neurodegenerative diseases therapy

Neurodegenerative diseases (NDD) are characterized by the gradual deterioration of neuronal function and integrity, resulting in an overall decline in brain function. The existing therapeutic options for NDD, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, fall short of meeting the clinical demand. A prominent pathological hallmark observed in numerous neurodegenerative disorders is the aggregation and misfolding of proteins both within and outside neurons. These abnormal proteins play a pivotal role in the pathogenesis of neurodegenerative diseases. Targeted degradation of irregular proteins offers a promising avenue for NDD treatment. Proteolysis-targeting chimeras (PROTACs) function via the ubiquitin-proteasome system and have emerged as a novel and efficacious approach in drug discovery. PROTACs can catalytically degrade "undruggable" proteins even at exceptionally low concentrations, allowing for precise quantitative control of aberrant protein levels. In this review, we present a compilation of reported PROTAC structures and their corresponding biological activities aimed at addressing NDD. Spanning from 2016 to present, this review provides an up-to-date overview of PROTAC-based therapeutic interventions. Currently, most protein degraders intended for NDD treatment remain in the preclinical research phase. Overcoming several challenges is imperative, including enhancing oral bioavailability and permeability across the blood-brain barrier, before these compounds can progress to clinical research or eventually reach the market. However, armed with an enhanced comprehension of the underlying pathological mechanisms and the emergence of innovative scaffolds for protein degraders, along with further structural optimization, we are confident that PROTAC possesses the potential to make substantial breakthroughs in the field of neurodegenerative diseases.

Cell-Penetrating Peptides: Promising Therapeutics and Drug-Delivery Systems for Neurodegenerative Diseases

Currently, one of the most significant and rapidly growing unmet medical challenges is the treatment of neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). This challenge encompasses the imperative development of efficacious therapeutic agents and overcoming the intricacies of the blood-brain barrier for successful drug delivery. Here we focus on the delivery aspect with particular emphasis on cell-penetrating peptides (CPPs), widely used in basic and translational research as they enhance drug delivery to challenging targets such as tissue and cellular compartments and thus increase therapeutic efficacy. The combination of CPPs with nanomaterials such as nanoparticles (NPs) improves the performance, accuracy, and stability of drug delivery and enables higher drug loads. Our review presents and discusses research that utilizes CPPs, either alone or in conjugation with NPs, to mitigate the pathogenic effects of neurodegenerative diseases with particular reference to AD and PD.

Antisense therapy: a potential breakthrough in the treatment of neurodegenerative diseases

Neurodegenerative diseases are a group of disorders characterized by the progressive degeneration of neurons in the central or peripheral nervous system. Currently, there is no cure for neurodegenerative diseases and this means a heavy burden for patients and the health system worldwide. Therefore, it is necessary to find new therapeutic approaches, and antisense therapies offer this possibility, having the great advantage of not modifying cellular genome and potentially being safer. Many preclinical and clinical studies aim to test the safety and effectiveness of antisense therapies in the treatment of neurodegenerative diseases. The objective of this review is to summarize the recent advances in the development of these new technologies to treat the most common neurodegenerative diseases, with a focus on those antisense therapies that have already received the approval of the U.S. Food and Drug Administration.

Therapeutic approaches in proteinopathies

A family of maladies known as amyloid disorders, proteinopathy, or amyloidosis, are characterized by the accumulation of abnormal protein aggregates containing cross-β-sheet amyloid fibrils in many organs and tissues. Often, proteins that have been improperly formed or folded make up these fibrils. Nowadays, most treatments for amyloid illness focus on managing symptoms rather than curing or preventing the underlying disease process. However, recent advances in our understanding of the biology of amyloid diseases have led to the development of innovative therapies that target the emergence and accumulation of amyloid fibrils. Examples of these treatments include the use of small compounds, monoclonal antibodies, gene therapy, and others. In the end, even if the majority of therapies for amyloid diseases are symptomatic, greater research into the biology behind these disorders is identifying new targets for potential therapy and paving the way for the development of more effective treatments in the future.

Gut instincts: Unveiling the connection between gut microbiota and Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder marked by neuroinflammation and gradual cognitive decline. Recent research has revealed that the gut microbiota (GM) plays an important role in the pathogenesis of AD through the microbiota-gut-brain axis. However, the mechanism by which GM and microbial metabolites alter brain function is not clearly understood. GM dysbiosis increases the permeability of the intestine, alters the blood-brain barrier permeability, and elevates proinflammatory mediators causing neurodegeneration. This review article introduced us to the composition and functions of GM along with its repercussions of dysbiosis in relation to AD. We also discussed the importance of the gut-brain axis and its role in communication. Later we focused on the mechanism behind gut dysbiosis and the progression of AD including neuroinflammation, oxidative stress, and changes in neurotransmitter levels. Furthermore, we highlighted recent developments in AD management, such as microbiota-based therapy, dietary interventions like prebiotics, probiotics, and fecal microbiota transplantation. Finally, we concluded with challenges and future directions in AD research based on GM.

Novel Pitolisant-Derived Sulfonyl Compounds for Alzheimer Disease

Alzheimer's disease (AD) is a complex and multifactorial neurodegenerative disorder characterized by cognitive decline, memory loss, behavioral changes, and other neurological symptoms. Considering the urgent need for new AD therapeutics, in the present study we designed, synthesized, and evaluated multitarget compounds structurally inspired by sulfonylureas and pitolisant with the aim of obtaining multitarget ligands for AD treatment. Due to the diversity of chemical scaffolds, a novel strategy has been adopted by merging into one structure moieties displaying H3R antagonism and acetylcholinesterase inhibition. Eight compounds, selected by their binding activity on H3R, showed a moderate ability to inhibit acetylcholinesterase activity in vitro, and two of the compounds (derivatives 2 and 7) were also capable of increasing acetylcholine release in vitro. Among the tested compounds, derivative 2 was identified and selected for further in vivo studies. Compound 2 was able to reverse scopolamine-induced cognitive deficits with results comparable to those of galantamine, a drug used in clinics for treating AD. In addition to its efficacy, this compound showed moderate BBB permeation in vitro. Altogether, these results point out that the fragment-like character of compound 2 leads to an optimal starting point for a plausible medicinal chemistry approach for this novel strategy.

Comprehensive Investigation of Natural Ligands as Inhibitors of β Secretase to Identify Alzheimer's Disease Therapeutics

INTRODUCTION

Alzheimer's disease (AD) is an alarmingly prevalent worldwide neurological disorder that affects millions of people and has severe effects on cognitive functions. The amyloid hypothesis, which links AD to Aβ (amyloid beta) plaque aggregation, is a well-acknowledged theory. The β-secretase (BACE1) is the main cause of Aβ production, which makes it a possible target for therapy. FDA-approved therapies for AD do exist, but none of them explicitly target BACE1, and their effectiveness is constrained and accompanied by adverse effects.

MATERIALS AND METHODS

We determined the essential chemical components of medicinal herbs by conducting a thorough literature research for BACE1. Computational methods like molecular docking, ADMET (Absorption, distribution, metabolism, excretion, toxicity) screening, molecular dynamic simulations, and MMPBSA analysis were performed in order to identify the most promising ligands for β-secretase.

RESULTS

The results suggested that withasomniferol, tinosporide, and curcumin had better binding affinity with BACE1, suggesting their potential as therapeutic candidates against Alzheimer's disease.

CONCLUSION

Herbal therapeutics have immense applications in the treatment of chronic diseases like Alzheimer's disease, and there is an urgent need to assess their efficacy as therapeutics.

Anti-amyloid potential of some phytochemicals against Aβ-peptide and α-synuclein, tau, prion, and Huntingtin protein

Some molecules self-assemble to create complex structures through molecular self-assembly. Hydrogel preparation, tissue repair, and therapeutic drug delivery are a few applications of molecular self-assembly. However, the self-assembly of amino acids, peptides, and proteins forms amyloid fibrils, resulting in various disorders, most notably neurodegenerative ailments. Examples include the self-assembly of phenylalanine, which causes phenylketonuria; Aβ, which causes Alzheimer's disease; the tau protein, which causes both Alzheimer's and Parkinson's diseases; and α-synuclein, which causes Parkinson's illness. This review provides information related to phytochemicals of great significance that can prevent the formation of, or destabilize, amino acid, peptide, and protein self-assemblies.

Synergistic neuroprotection by phytocompounds of Bacopa monnieri in scopolamine-induced Alzheimer's disease mice model

BACKGROUND

Millions of people around the globe are affected by Alzheimer's disease (AD). This crippling condition has no treatment despite intensive studies. Some phytocompounds have been shown to protect against Alzheimer's in recent studies.

METHODS

Thus, this work aimed to examine Bacopa monnieri phytocompounds' synergistic effects on neurodegeneration, antioxidant activity, and cognition in the scopolamine-induced AD mice model. The toxicity study of two phytocompounds: quercetin and bacopaside X revealed an LD50 of more than 2000 mg/kg since no deaths occurred.

RESULTS

The neuroprotection experiment consists of 6 groups i.e., control (saline), scopolamine (1 mg/kg), donepezil (5 mg/kg), Q (25 mg/kg), BX (20 mg/kg), and Q + BX (25 mg/kg + 20 mg/kg). Visual behavioral assessment using the Morris water maze showed that animals in the diseased model group (scopolamine) moved more slowly toward the platform and exhibited greater thigmotaxis behavior than the treatment and control groups. Likewise, the concentration of biochemical NO, GSH, and MDA improved in treatment groups concerning the diseased group. mRNA levels of different marker genes including ChAT, IL-1α, IL-1 β, TNF α, tau, and β secretase (BACE1) improved in treatment groups with respect to the disease group.

CONCLUSION

Both bacopaside X and quercetin synergistically have shown promising results in neuroprotection. Therefore, it is suggested that Q and BX may work synergistically due to their antioxidant and neuroprotective property.

A New Perspective for the Treatment of Alzheimer's Disease: Exosome-like Liposomes to Deliver Natural Compounds and RNA Therapies

With the increment of the aging population in recent years, neurodegenerative diseases exert a major global disease burden, essentially as a result of the lack of treatments that stop the disease progression. Alzheimer's Disease (AD) is an example of a neurodegenerative disease that affects millions of people globally, with no effective treatment. Natural compounds have emerged as a viable therapy to fill a huge gap in AD management, and in recent years, mostly fueled by the COVID-19 pandemic, RNA-based therapeutics have become a hot topic in the treatment of several diseases. Treatments of AD face significant limitations due to the complex and interconnected pathways that lead to their hallmarks and also due to the necessity to cross the blood-brain barrier. Nanotechnology has contributed to surpassing this bottleneck in the treatment of AD by promoting safe and enhanced drug delivery to the brain. In particular, exosome-like nanoparticles, a hybrid delivery system combining exosomes and liposomes' advantageous features, are demonstrating great potential in the treatment of central nervous system diseases.

Protein aggregation and neurodegenerative disease: Structural outlook for the novel therapeutics

Before the controversial approval of humanized monoclonal antibody lecanemab, which binds to the soluble amyloid-β protofibrils, all the treatments available earlier, for Alzheimer's disease (AD) were symptomatic. The researchers are still struggling to find a breakthrough in AD therapeutic medicine, which is partially attributable to lack in understanding of the structural information associated with the intrinsically disordered proteins and amyloids. One of the major challenges in this area of research is to understand the structural diversity of intrinsically disordered proteins under in vitro conditions. Therefore, in this review, we have summarized the in vitro applications of biophysical methods, which are aimed to shed some light on the heterogeneity, pathogenicity, structures and mechanisms of the intrinsically disordered protein aggregates associated with proteinopathies including AD. This review will also rationalize some of the strategies in modulating disease-relevant pathogenic protein entities by small molecules using structural biology approaches and biophysical characterization. We have also highlighted tools and techniques to simulate the in vivo conditions for native and cytotoxic tau/amyloids assemblies, urge new chemical approaches to replicate tau/amyloids assemblies similar to those in vivo conditions, in addition to designing novel potential drugs.

Microorganism-Derived Molecules as Enzyme Inhibitors to Target Alzheimer's Diseases Pathways

Alzheimer's disease (AD) is the most common form of dementia. It increases the risk of other serious diseases and causes a huge impact on individuals, families, and socioeconomics. AD is a complex multifactorial disease, and current pharmacological therapies are largely based on the inhibition of enzymes involved in the pathogenesis of AD. Natural enzyme inhibitors are the potential sources for targeting AD treatment and are mainly collected from plants, marine organisms, or microorganisms. In particular, microbial sources have many advantages compared to other sources. While several reviews on AD have been reported, most of these previous reviews focused on presenting and discussing the general theory of AD or overviewing enzyme inhibitors from various sources, such as chemical synthesis, plants, and marine organisms, while only a few reviews regarding microbial sources of enzyme inhibitors against AD are available. Currently, multi-targeted drug investigation is a new trend for the potential treatment of AD. However, there is no review that has comprehensively discussed the various kinds of enzyme inhibitors from the microbial source. This review extensively addresses the above-mentioned aspect and simultaneously updates and provides a more comprehensive view of the enzyme targets involved in the pathogenesis of AD. The emerging trend of using in silico studies to discover drugs concerning AD inhibitors from microorganisms and perspectives for further experimental studies are also covered here.

Neuroprotective Effect of α-Lipoic Acid against Aβ25-35-Induced Damage in BV2 Cells

The prevalence of Alzheimer's disease (AD) is significantly increasing due to the aging world population, and the currently available drug treatments cannot cure or even slow its progression. α-lipoic acid (LA) is a biological factor widely found in spinach and meat and can dissolve in both lipid and aqueous phases. In medicine, LA has been shown to reduce the symptoms of diabetic polyneuropathy, acute kidney injury, cancers, and some metabolism-related diseases. This study to proves that α-lipoic acid (LA) can stabilize the cognitive function of patients with Alzheimer's disease (AD). BV2 cells were divided into control, LA, Aβ_25-35, and LA + Aβ_25-35 groups. Cell growth; IL-6, IL-1β, TNF-α, IFN-γ, SOD, GPx, CAT, ROS, NO, and iNOS secretion; Wnt-related proteins; cell apoptosis; and cell activation were examined. Here, we found that LA could effectively repress apoptosis and changes in the morphology of microglia BV2 cells activated by Aβ_25-35, accompanied by the inhibition of the inflammatory response induced by Aβ_25-35. The Wnt/β-catenin pathway is also involved in preventing Aβ_25-35-induced cytotoxicity in microglia by LA. We found an inhibitory effect of LA on microglia toxicity induced by Aβ_25-35, suggesting that a combination of anti-inflammatory and antioxidant substances may offer a promising approach to the treatment of AD.

Recent Updates on the Development of Therapeutics for the Targeted Treatment of Alzheimer's Disease

Alzheimer's disease (AD) is a complicated, multifaceted, irreversible, and incurable neurotoxic old age illness. Although NMDA (N-methyl D-aspartate)-receptor antagonists, cholinesterase repressors, and their pairings have been approved for the treatment, they are useful for short symptomatic relief. Researchers throughout the globe have been constantly working to uncover the therapy of Alzheimer's disease as new candidates must be determined, and newer treatment medicines must be developed. The aim of this review is to address recent advances in medication research along with new Alzheimer's disease therapy for diverse targets. Information was gathered utilizing a variety of internet resources as well as websites, such as ALZFORUM (alzforum.org) and clinicaltrials.gov. In contrast to other domains, the proposed medicines target amyloids (secretases, A42 generation, neuroinflammation, amyloid precipitation, and immunization), tau proteins (tau phosphorylation/aggregation and immunotherapy), and amyloid deposition. Despite tremendous advancement in our understanding of the underlying pathophysiology of Alzheimer's disease, the FDA (Food and Drug Administration) only approved aducanumab for diagnosis and treatment in 2003. Hence, novel treatment tactics are needed to find and develop therapeutic medicines to combat Alzheimer's disease.