Rutin improves spatial memory in Alzheimer's disease transgenic mice by reducing Aβ oligomer level and attenuating oxidative stress and neuroinflammation

Metabolic reprogramming through histone lactylation in microglia and macrophages recruits CD8+ T lymphocytes and aggravates spinal cord injury

Crosstalk between the central nervous system (CNS) and the immune system has recently gained increased attention; however, the interaction between innate and adaptive immunity after CNS injury remains unclear. Here, using single-cell RNA sequencing, we identified accumulation of CD8+ T lymphocytes in the cerebrospinal fluid of patients with spinal cord injury (SCI) and in spinal cords of injured mice, thus indicating poor neurological function. Furthermore, through genetic or pharmacologic interruption strategies, we found that CXCL16 chemokines derived from injury-activated microglia and macrophages (IAMs) recruited CXCR6+CD8+ T cells and further contributed to neuronal loss after SCI. Mechanistically, glycolytic reprogramming in IAMs enhanced histone-lactylation-mediated Cxcl16 transcription, whereas suppressing glycolysis through Pkm2 deletion partially reversed this effect. Notably, a pharmacologic intervention targeting the CXCL16-CXCR6 axis with Rutin promoted locomotor restoration after SCI. Our study highlights the crucial role of glycolytically reprogrammed IAM-derived CXCL16 chemokines in modulating a maladaptive innate/adaptive immune axis and reveals several potential therapeutic strategies.

Rutin ameliorates stress-induced blood‒brain barrier dysfunction and cognitive decline via the endothelial HDAC1‒Claudin-5 axis

BACKGROUND

Emerging evidence suggests that chronic stress compromises blood‒brain barrier (BBB) integrity by disrupting brain microvascular endothelial cells (BMECs), contributing to the development of cognitive impairments. Thus, targeting the BBB is expected to be a promising treatment strategy. The biological function of rutin has been investigated in neurological disorders; however, its regulatory role in stress-induced BBB damage and cognitive decline and the underlying mechanisms remain elusive.

METHODS

In a chronic unpredictable mild stress (CUMS) mouse model, a fluorescent dye assay and behavioral tests, including a novel object recognition test and Morris water maze, were performed to evaluate the protective effects of rutin on BBB integrity and cognition. The effects of rutin on BMEC function were also investigated in hCMEC/D3 cells (a human brain microvascular endothelial cell line) in vitro. Furthermore, the molecular mechanisms by which rutin restores BBB endothelium dysfunction were explored via RNA-seq, quantitative real-time PCR, western blotting, immunofluorescence and chromatin immunoprecipitation. Finally, biotinylated tumor necrosis factor-α (TNF-α) was employed to test the influence of rutin on the ability of circulating TNF-α to cross the BBB.

RESULTS

We identified that rutin attenuated BBB hyperpermeability and cognitive impairment caused by the 8-week CUMS procedure. Moreover, rutin promoted the proliferation, migration and angiogenesis ability of BMECs, and the integrity of the cellular monolayer through positively regulating the expression of genes involved. Furthermore, rutin impeded histone deacetylase 1 (HDAC1) recruitment and stabilized H3K27ac to increase Claudin-5 protein levels. Ultimately, normalization of the hippocampal HDAC1‒Claudin-5 axis by rutin blocked the infiltration of circulating TNF-α into the brain parenchyma and alleviated neuroinflammation.

CONCLUSIONS

This work establishes a protective role of rutin in regulating BMEC function and BBB integrity, and reveals that rutin is a potential drug candidate for curing chronic stress-induced cognitive deficits.

Plant-Based Inhibitors of Protein Aggregation

The assembly of amyloidogenic proteins and peptides into toxic oligomeric and fibrillar aggregates is closely connected to the onset and progression of more than 50 protein diseases, such as Alzheimer's disease, Parkinson's disease, prion disease, and type 2 diabetes, to name only a few. Considerable research efforts at identifying the therapeutic strategies against these maladies are currently focused on preventing and inhibiting pathogenic protein aggregation by various agents. Plant-based extracts and compounds have emerged as promising sources of potential inhibitors due to their dual role as nutraceuticals as part of healthy diets and as specific pharmaceuticals when administered at higher concentrations. In recent decades, several plant extracts and plant-extracted compounds have shown potential to modulate protein aggregation. An ever-growing body of research on plant-based amyloid inhibitors requires a detail analysis of existing data to identify potential knowledge gaps. This review summarizes the recent progress in amyloid inhibition using 17 flavonoids, 11 polyphenolic non-flavonoid compounds, 23 non-phenolic inhibitors, and 59 plant extracts, with the main emphasis on directly modulating the fibrillation of four amyloid proteins, namely amyloid-β peptide, microtubule-associated protein tau, α-synuclein, and human islet amyloid polypeptide.

Ligature-induced periodontitis in a transgenic mouse model of Alzheimer's disease dysregulates neuroinflammation, exacerbates cognitive impairment, and accelerates amyloid pathology

A growing body of literature has identified periodontal disease among the modifiable risk factors for Alzheimer's disease (AD), but the mechanisms underlying this relationship is unknown. This study investigated this relationship using a ligature-induced preclinical periodontitis (Pd) model in non-transgenic (non-Tg) and 3xTg-AD mice. We found that ligature placement caused significant alveolar bone loss, with 3xTg-AD mice exhibiting exacerbated bone loss, suggesting AD-related genetic risk may amplify disease progression. Pd induced robust local inflammatory gene expression in both genotypes, but 3xTg-AD mice indicated a dysregulated immune response. Cognitive deficits were observed only in Pd-afflicted 3xTg-AD mice, specifically in hippocampus-mediated spatial memory and perirhinal cortex-mediated object recognition memory, while non-Tg mice remained unaffected. Neuroinflammatory responses varied by brain region, with the hippocampus and prefrontal cortex (PFC) showing the most pronounced changes. In these regions, 3xTg-AD mice exhibited significantly altered cytokine gene expression compared to non-Tg mice, particularly at later time points. Synaptic markers revealed vulnerabilities in 3xTg-AD mice, including reduced baseline Syp expression and dysregulated Synpo post-ligature. Pd transiently reduced glutamate receptor gene expression in both genotypes, with non-Tg mice showing persistent changes, potentially linked to preserved memory. Pd also accelerated amyloid-β (Aβ) deposition and sustained neurodegeneration in 3xTg-AD mice. Overall, this study shows that combining Pd and AD-related genetic risk exacerbates inflammation, cognitive impairment, synaptic dysfunction, Aβ pathology, and neurodegeneration. Neither insult alone was sufficient to produce these effects, highlighting the synergistic impact. These findings emphasize the need to explore anti-inflammatory interventions and downstream mechanisms to mitigate the confluence of these diseases.

Cellular stress response and neuroprotection of flavonoids in neurodegenerative diseases: Clinical insights into targeted therapy and molecular signaling pathways

Neurodegenerative diseases (NDs) are caused by the gradual decline of neuronal structure and function, which presents significant challenges in treatment. Cellular stress responses significantly impact the pathophysiology of these disorders, often exacerbating neuronal damage. Plant-derived flavonoids have demonstrated potential as neuroprotective agents due to their potent anti-inflammatory, anti-apoptotic, and antioxidant properties. This review provides an in-depth analysis of the molecular processes and clinical insights that cause the neuroprotective properties of flavonoids in NDs. By controlling essential signaling pathways such as Nrf2/ARE, MAPK, and PI3K/Akt, flavonoids can lower cellular stress and improve neuronal survival. The study discusses the challenges of implementing these discoveries in clinical practice and emphasizes the therapeutic potential of specific flavonoids and their derivatives. Flavonoids are identified as potential therapeutic agents for NDs, potentially slowing progression by regulating cellular stress and improving neuroprotection despite their potential medicinal uses and clinical challenges. The study designed a strategy to identify literature published in prestigious journals, utilizing search results from PubMed, Scopus, and WOS. We selected and investigated original studies, review articles, and research reports published until 2024. It suggests future research and therapeutic approaches to effectively utilize the neuroprotective properties of flavonoids.

Network pharmacological analysis and in vitro testing of the rutin effects on triple-negative breast cancer

Objectives

This study aims to assess the potential mechanism of rutin to treat triple-negative breast cancer (TNBC) based on network pharmacology followed by in vitro experiments.

Methods

The potential rutin targets were predicted, and the DisGeNET database was used to obtain the disease targets. The intersection targets were identified with Venny 2.1 software, with the String database subsequently used as input to produce the "drug-target-disease" visual network employing Cytoscape 3.7.2. Gene ontology. Kyoto Encyclopaedia of Genes and Genomes analyses were performed for intersection targets, while AutoDock Vina was used for molecular docking and visualization. Cell viability was assessed using the Colorimetric CCK-8 test, and apoptosis was analyzed using PI/Annexin V. The predicted core targets were confirmed by qPCR and western blotting assays.

Results

EGFR, IL6, TNF, and INS were found as the primary targets. The molecular docking analysis revealed the rutin interaction with the core targets. The in vitro results confirmed that rutin inhibited the growth of the MDA-MB-231 cell line. Rutin also induced cell death and decreased the expressions of IL6, TNF, INS, and EGFR.

Conclusion

Rutin's multi-target effects and molecular mechanism for treating TNBC were confirmed through preliminary results. The results provide a theoretical base for rutin's possible function in breast cancer treatment.

Restoring adapter protein complex 4 function with small molecules: an in silico approach to spastic paraplegia 50

This study focuses on spastic paraplegia type 50 (SPG50), an adapter protein complex 4 deficiency syndrome caused by mutations in the adapter protein complex 4 subunit mu-1 (AP4M1) gene, and on the downstream alterations of the AP4M1 protein. We applied a battery of heterogeneous computational resources, encompassing two in-house tools described here for the first time, to (a) assess the druggability potential of AP4M1, (b) characterize SPG50-associated mutations and their 3D scenario, (c) identify mutation-tailored drug candidates for SPG50, and (d) elucidate their mechanisms of action by means of structural considerations on homology models of the adapter protein complex 4 core. Altogether, the collected results indicate R367Q as the mutation with the most promising potential of being corrected by small-molecule drugs, and the flavonoid rutin as best candidate for this purpose. Rutin shows promise in rescuing the interaction between the AP4M1 and adapter protein complex subunit beta-1 (AP4B1) subunits by means of a glue-like mode of action. Overall, this approach offers a framework that could be systematically applied to the investigation of mutation-wise molecular mechanisms in different hereditary spastic paraplegias, too.

Oxalis erythrorhiza Gillies ex Hooker et Arnott (Oxalidaceae): Chemical Analysis, Biological In Vitro and In Vivo Properties and Behavioral Effects

In this work, a decoction (DOe) and a methanolic global extract (MGEOe), obtained with the aerial parts of Oxalis erythrorhiza Gillies ex Hooker et Arnott (Oxalidaceae), were evaluated. The high-resolution liquid chromatography in conjunction with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS) analysis showed forty compounds in MGEOe and twenty-nine in DOe, including flavones, C-glycosyl flavones, isoflavones, fatty acids, terpenes, phenolic acids, and sterols. The antioxidant properties were evaluated by DPPH, TEAC, FRAP, and ILP assays. Both DOe and MGEOe showed stronger antioxidant activities. The anti-inflammatory effects were evaluated by COX inhibition method, where DOe demonstrated a significant inhibitory effect. The cytotoxic effects were evaluated in the tumoral HCT-116 and non-tumoral HBL-100 cell lines, revealing a selective action from DOe and MGOe on cancer cells. DOe was evaluated in an animal model of insulin resistance, which is characterized by alterations in glucose and lipid metabolism, as well as cognitive impairments, including anxiety-like behavior and memory deficits. Male SD rats received sucrose (10% w/v, SUC), a half dilution of DOe (5% w/v) with sucrose (HDOeS) or DOe with sucrose (DOeS) from PND21 to PND61. Then, anxiety-like behavior and spatial memory were assessed using the open field (OF), elevated plus maze (EPM) and the novel object location (NOL) tests, respectively. Serum parameters basal glycemia, total cholesterol (TC) and tryglicerides were measured using commercial kits. The lipid peroxidation was determined in homogenates of cerebral cortex, hippocampus and hypothalamus by TBAR assay. Only HDOeS exhibited lower anxiety-like behavior in OF and improved performance in NOL compared to SUC. Furthermore, DOeS showed reduced serum parameters, while HDOeS presented lower TC levels than SUC. No differences were observed on TBAR assay. The beneficial properties of these preparations could be attributed to the identified metabolites. These findings highlighted O. erythrorhiza as a potential source of compounds to improve human health; however, further research is required to elucidate its mechanisms of action.

Establishing network pharmacology between natural polyphenols and Alzheimer's disease using bioinformatic tools - An advancement in Alzheimer's research

Alzheimer's disease (AD) is a major cause of disability and one of the top causes of mortality globally. AD remains a major public health challenge due to its prevalence, impact on patients and caregivers, and the current lack of a cure. In recent years, polyphenols have garnered attention for their potential therapeutic effects on AD. The objective of the study was to establish network pharmacology between selected polyphenols of plant origin and AD. Insilico tools such as SwissADME, ProTox3.0, pkCSM, Swiss Target Prediction, DisGeNET, InterActiVenn, DAVID database, STRING database, Cytoscape/CytoHubba were employed to establish the multi-target potential of the polyphenolic compounds. The present study revealed that out of 17 polyphenols, 10 ligands were found to possess a drug-likeness nature along with desirable pharmacokinetic parameters and a lesser toxicity profile. Also, the results highlighted the possible interactions between the polyphenols and the disease targets involved in AD. Further, this study has shed light on the mTOR pathway and its impact on AD through the autophagic mechanism. Overall, this study indicated that polyphenols could be a better therapeutic option for treating AD. Hence, the consumption of polyphenolic cocktails as a part of the diet could produce more effective outcomes against the disease. Additional studies are warranted in the future to explore additional pathways and genes to provide a comprehensive understanding regarding the usage of the shortlisted polyphenols and their derivatives for the prevention and treatment of AD.

The Potential Effects of Red Wine and Its Components on Neurocognitive Disorders: A Narrative Review

BACKGROUND

The aging population is associated with a net increase in the incidence and prevalence of chronic-degenerative diseases, particularly neurocognitive disorders. Therefore, the identification of preventative strategies to restrain the burden of such chronic conditions is of key relevance. Red wine and its components have accumulated evidence regarding their positive effects in terms of neurological pathologies associated with neurocognitive symptoms.

METHODS

Based on this background, the present narrative review aims to summarize the state-of-the-art evidence on the effects of red wine and its components on neurocognitive disorders in both preclinical and clinical settings.

RESULTS

The main findings highlight a protective effect of wine polyphenols present in red wine on dementia in different preclinical models of cognitive decline. The current translational clinical evidence remains uncertain, especially considering the risk-to-benefit ratio of alcohol consumption on brain health.

CONCLUSIONS

Given the overall health risks associated with red wine consumption and consistent with the prevailing guidelines in the literature, there is insufficient evidence to support light-to-moderate red wine consumption as an effective strategy for preventing these diseases. However, the largely preclinical findings on polyphenols derived from red wine remain of significant interest in this context.

Natural products targeting amyloid-β oligomer neurotoxicity in Alzheimer's disease

Alzheimer's disease (AD) constitutes a major global health issue, characterized by progressive neurodegeneration and cognitive impairment, for which no curative treatment is currently available. Current therapeutic approaches are focused on symptom management, highlighting the critical need for disease-modifying therapy. The hallmark pathology of AD involves the aggregation and accumulation of amyloid-β (Aβ) peptides in the brain. Consequently, drug discovery efforts in recent decades have centered on the Aβ aggregation cascade, which includes the transition of monomeric Aβ peptides into toxic oligomers and, ultimately, mature fibrils. Historically, anti-Aβ strategies focused on the clearance of amyloid fibrils using monoclonal antibodies. However, substantial evidence has highlighted the critical role of Aβ oligomers (AβOs) in AD pathogenesis. Soluble AβOs are now recognized as more toxic than fibrils, directly contributing to synaptic impairment, neuronal damage, and the onset of AD. Targeting AβOs has emerged as a promising therapeutic approach to mitigate cognitive decline in AD. Natural products (NPs) have demonstrated promise against AβO neurotoxicity through various mechanisms, including preventing AβO formation, enhancing clearance mechanisms, or converting AβOs into non-toxic species. Understanding the mechanisms by which anti-AβO NPs operate is useful for developing disease-modifying treatments for AD. In this review, we explore the role of NPs in mitigating AβO neurotoxicity for AD drug discovery, summarizing key evidence from biophysical methods, cellular assays, and animal models. By discussing how NPs modulate AβO neurotoxicity across various experimental systems, we aim to provide valuable insights into novel therapeutic strategies targeting AβOs in AD.

Rutin Ameliorates ALS Pathology by Reducing SOD1 Aggregation and Neuroinflammation in an SOD1-G93A Mouse Model

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive loss of motor neurons, with limited effective treatments. Recently, the exploration of natural products has unveiled their potential in exerting neuroprotective effects, offering a promising avenue for ALS therapy. In this study, the therapeutic effects of rutin, a natural flavonoid glycoside with neuroprotective properties, were evaluated in a superoxide dismutase 1 (SOD1)-G93A mouse model of ALS. We showed that rutin reduced the level of SOD1 aggregation and diminished glial cell activation in spinal cords and brainstems, resulting in significantly improved motor function and motor neuron restoration in SOD1-G93A mice. Our findings indicated that rutin's multi-targeted approach to SOD1-related pathology makes it a promising candidate for the treatment of ALS.

Unveiling the impact of aging on BBB and Alzheimer's disease: Factors and therapeutic implications

Alzheimer's disease (AD) is a highly prevalent neurodegenerative condition that has devastating effects on individuals, often resulting in dementia. AD is primarily defined by the presence of extracellular plaques containing insoluble β-amyloid peptide (Aβ) and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein (P-tau). In addition, individuals afflicted by these age-related illnesses experience a diminished state of health, which places significant financial strain on their loved ones. Several risk factors play a significant role in the development of AD. These factors include genetics, diet, smoking, certain diseases (such as cerebrovascular diseases, obesity, hypertension, and dyslipidemia), age, and alcohol consumption. Age-related factors are key contributors to the development of vascular-based neurodegenerative diseases such as AD. In general, the process of aging can lead to changes in the immune system's responses and can also initiate inflammation in the brain. The chronic inflammation and the inflammatory mediators found in the brain play a crucial role in the dysfunction of the blood-brain barrier (BBB). Furthermore, maintaining BBB integrity is of utmost importance in preventing a wide range of neurological disorders. Therefore, in this review, we discussed the role of age and its related factors in the breakdown of the blood-brain barrier and the development of AD. We also discussed the importance of different compounds, such as those with anti-aging properties, and other compounds that can help maintain the integrity of the blood-brain barrier in the prevention of AD. This review builds a strong correlation between age-related factors, degradation of the BBB, and its impact on AD.

Dietary anti-inflammatory and anti-bacterial medicinal plants and its compounds in bovine mastitis associated impact on human life

Bovine mastitis (BM) is the most common bacterial mediated inflammatory disease in the dairy cattle that causes huge economic loss to the dairy industry due to decreased milk quality and quantity. Milk is the essential food in the human diet, and rich in crucial nutrients that helps in lowering the risk of diseases like hypertension, cardiovascular diseases and type 2 diabetes. The main causative agents of the disease include various gram negative, and positive bacteria, along with other risk factors such as udder shape, age, genetic, and environmental factors also contributes much for the disease. Currently, antibiotics, immunotherapy, probiotics, dry cow, and lactation therapy are commonly recommended for BM. However, these treatments can only decrease the rise of new cases but can't eliminate the causative agents, and they also exhibit several limitations. Hence, there is an urgent need of a potential source that can generate a typical and ideal treatment to overcome the limitations and eliminate the pathogens. Among the various sources, medicinal plants and its derived products always play a significant role in drug discovery against several diseases. In addition, they are also known for its low toxicity and minimum resistance features. Therefore, plants and its compounds that possess anti-inflammatory and anti-bacterial properties can serve better in bovine mastitis. In addition, the plants that are serving as a food source and possessing pharmacological properties can act even better in bovine mastitis. Hence, in this evidence-based study, we particularly review the dietary medicinal plants and derived products that are proven for anti-inflammatory and anti-bacterial effects. Moreover, the role of each dietary plant and its compounds along with possible role in the management of bovine mastitis are delineated. In this way, this article serves as a standalone source for the researchers working in this area to help in the management of BM.

Simultaneous estimation of rutin and donepezil through RP-HPLC: implication in pharmaceutical and biological samples

Aim: A HPLC method was developed and validated for the novel combination of rutin (RN) and donepezil (DNP). Materials & methods: RN and DNP were simultaneously eluted through a C18 column (Ø 150 × 4.6 mm) with a 60:40 v/v ratio of 0.1% formic acid aqueous solution to methanol at 0.5 ml/min. Results: The purposed method was found linear, selective, reproducible, accurate and precise with percent RSD less than 2. The limit of quantification for RN and DNP was found 3.66 and 3.25 μg/ml, respectively. Conclusion: Validated as per the ICH guidelines, the developed method efficiently quantified RN and DNP co-loaded in DQAsomes (121 nm) estimating matrix effect, release profile, entrapment efficiency, loading efficiency and in vivo plasma kinetics.

Therapeutic effects of tetrandrine in inflammatory diseases: a comprehensive review

Inflammation can be triggered by any factor. The primary pathological manifestations can be summarized as the deterioration, exudation, and proliferation of local tissues, which can cause systemic damage in severe cases. Inflammatory lesions are primarily localized but may interact with body systems to cause provocative storms, parenchymal organ lesions, vascular and central nervous system necrosis, and other pathologic responses. Tetrandrine (TET) is a bisbenzylquinoline alkaloid extracted from the traditional Chinese herbal medicine Stephania tetrandra, which has been shown to have significant efficacy in inflammatory conditions such as rheumatoid arthritis, hepatitis, nephritis, etc., through NF-κB, MAPK, ERK, and STAT3 signaling pathways. TET can regulate the body's imbalanced metabolic pathways, reverse the inflammatory process, reduce other pathological damage caused by inflammation, and prevent the vicious cycle. More importantly, TET does not disrupt body's normal immune function while clearing the body's inflammatory state. Therefore, it is necessary to pay attention to its dosage and duration during treatment to avoid unexpected side effects caused by a long half-life. In summary, TET has a promising future in treating inflammatory diseases. The author reviews current therapeutic studies of TET in inflammatory conditions to provide some ideas for subsequent anti-inflammatory studies of TET.

Multi-omics identification of a key glycosyl hydrolase gene FtGH1 involved in rutin hydrolysis in Tartary buckwheat (Fagopyrum tataricum)

Rutin, a flavonoid rich in buckwheat, is important for human health and plant resistance to external stresses. The hydrolysis of rutin to quercetin underlies the bitter taste of Tartary buckwheat. In order to identify rutin hydrolysis genes, a 200 genotypes mini-core Tartary buckwheat germplasm resource was re-sequenced with 30-fold coverage depth. By combining the content of the intermediate metabolites of rutin metabolism with genome resequencing data, metabolite genome-wide association analyses (GWAS) eventually identified a glycosyl hydrolase gene FtGH1, which could hydrolyse rutin to quercetin. This function was validated both in Tartary buckwheat overexpression hairy roots and in vitro enzyme activity assays. Mutation of the two key active sites, which were determined by molecular docking and experimentally verified via overexpression in hairy roots and transient expression in tobacco leaves, exhibited abnormal subcellular localization, suggesting functional changes. Sequence analysis revealed that mutation of the FtGH1 promoter in accessions of two haplotypes might be necessary for enzymatic activity. Co-expression analysis and GWAS revealed that FtbHLH165 not only repressed FtGH1 expression, but also increased seed length. This work reveals a potential mechanism behind rutin metabolism, which should provide both theoretical support in the study of flavonoid metabolism and in the molecular breeding of Tartary buckwheat.

To evaluate the effect of endothelin receptor agonist IRL-1620 alone and in combination with donepezil in modulating neurodegeneration elicited by amyloid-β in rats

BACKGROUND

The development of efficient therapies for Alzheimer''s disease is essential since it is a serious public health problem. This investigation sought to ascertain any potential synergistic benefits of treating Alzheimer's disease with IRL-1620 monotherapy in addition to Donepezil. Additionally, the effect of IRL-1620 was evaluated using different doses (5 μg/kg,7 μg/kg, and 9 μg/kg). The study further assessed neurobehavioral, biochemical, molecular, and histopathological parameters to evaluate the efficacy of both IRL1620 by its own and in association with Donepezil. Fifty-eight adult male Wistar rats were allocated to eight experimental groups. A dose-ranging study of IRL-1620 was conducted using different doses administered via intravenous injection. Alzheimer's disease was induced by Aβ administration, and treatment arms included disease Control (Sham), Donepezil monotherapy, and combination treatment with IRL-1620 5 μg/kg (Dose selected from the dose-ranging study). The treatment using IRL-1620 (9 μg/kg) intravenously and Donepezil (1 mg/kg orally) both on its own and in addition substantially enhanced memory in comparison with the control group (p < 0.05). Dose of IRL-1620 (9 μg/kg) intravenously, escape latency decreased and the time spent in the target quadrant was considerably increased, and they further benefited from combination therapy. Moreover, IRL-1620 (9 μg/kg) intravenously and combination treatment reduced lipid peroxidation and acetylcholinesterase levels while increasing antioxidant enzyme levels. Immunohistochemistry and molecular analysis revealed enhanced expression of neurotrophic factors with combination treatment. The combination of IRL-1620 and Donepezil showed significant improvements in memory and neurobehavioral parameters (p < 0.05). Alzheimer's disease in male Wistar rats. These results indicate to the probable therapeutic advantages of IRL-1620 and Donepezil in the management of Alzheimer's disease. The combination treatment exhibited enhanced effects compared to monotherapy, highlighting its potential promising therapeutic approach. Additional research is required to understand the mechanisms behind these synergistic benefits and to establish the ideal dosage and duration of therapy for therapeutic applications.

Hawaiian native herb Mamaki prevents dementia by ameliorating neuropathology and repairing neurons in four different mouse models of neurodegenerative diseases

Neurodegenerative diseases including Alzheimer's disease, frontotemporal dementia, and dementia with Lewy bodies are age-related disorders and the main cause of dementia. They are characterized by the cerebral accumulation of Aβ, tau, α-synuclein, and TDP-43. Because the accumulation begins decades before disease onset, treatment should be started in the preclinical stage. Such intervention would be long-lasting, and therefore, prophylactic agents should be safe, non-invasively taken by the patients, and inexpensive. In addition, the agents should be broadly effective against etiologic proteins and capable of repairing neurons damaged by toxic oligomers. These requirements are difficult to meet with single-ingredient pharmaceuticals but may be feasible by taking proper diets composed of multiple ingredients. As a source of such diets, we focused on the Hawaiian native herb Mamaki. From its dried leaves and fruits, we made three preparations: hot water extract of the leaves, non-extracted simple crush powder of the leaves, and simple crush powder of the fruits, and examined their effects on the cognitive function and neuropathologies in four different mouse models of neurodegenerative dementia. Hot water extract of the leaves attenuated neuropathologies, restored synaptophysin levels, suppressed microglial activation, and improved memory when orally administered for 1 month. Simply crushed leaf powder showed a higher efficacy, but simply crushed fruit powder displayed the strongest effects. Moreover, the fruit powder significantly enhanced the levels of brain-derived neurotrophic factor expression and neurogenesis, indicating its ability to repair neurons. These results suggest that crushed Mamaki leaves and fruits are promising sources of dementia-preventive diets.

Oral administration of phytochemicals protects honey bees against cognitive and motor impairments induced by the insecticide fipronil

Pollution produced by exposure to pesticides is a major concern for food security because the negative impacts on pollinators. Fipronil, an insecticide broadly used around the globe has been associated with the ongoing decline of bees. With a characteristic neuroactive toxicodynamic, fipronil leads to cognitive and motor impairments at sublethal dosages. Despite of regional bans, multilevel strategies are necessary for the protection of pollinators. Recent evidence suggests that specific nutrients in the diets of bees may induce protection against insecticides. Here, we evaluated whether the administration of three phytochemicals, namely rutin, kaempferol and p-coumaric acid provide protection to the Africanized honey bee Apis mellifera against oral administration of realistic dosages of fipronil. We tested the potential impairment produced by fipronil and the protection induced by the phytochemicals in learning, 24h memory, sucrose sensitivity and motor control. We found that the administration of fipronil induced a concentration-dependent impairment in learning and motor control, but not 24h memory or sucrose sensitivity across a 24h window. We also found that the administration of rutin, p-coumaric acid, kaempferol and the mixture was innocuous and generally offered protection against the impairments induced by fipronil. Overall, our results indicate that bees can be prophylactically protected against insecticides via nutrition, providing an alternative to the ongoing conflict between the use of insecticides and the decline of pollinators. As the studied phytochemicals are broadly present in nectar and pollen, our results suggest that the nutritional composition, and not only its production, should be considered when implementing strategies of conservation via gardens and co-cropping.

In Silico Insights into Micro-Mechanism Understanding of Extracts of Taxus Chinensis Fruits Against Alzheimer's Disease

BACKGROUND

The taxus chinensis fruit (TCF) shows promises in treatment of aging-related diseases such as Alzheimer's disease (AD). However, its related constituents and targets against AD have not been deciphered.

OBJECTIVE

This study was to uncover constituents and targets of TCF extracts against AD.

METHODS

An integrated approach including ultrasound extractions and constituent identification of TCF by UPLC-QE-MS/MS, target identification of constituents and AD by R data-mining from Pubchem, Drugbank and GEO databases, network construction, molecular docking and the ROC curve analysis was carried out.

RESULTS

We identified 250 compounds in TCF extracts, and obtained 3,231 known constituent targets and 5,326 differential expression genes of AD, and 988 intersection genes. Through the network construction and KEGG pathway analysis, 19 chemicals, 31 targets, and 11 biological pathways were obtained as core compounds, targets and pathways of TCF extracts against AD. Among these constituents, luteolin, oleic acid, gallic acid, baicalein, naringenin, lovastatin and rutin had obvious anti-AD effect. Molecular docking results further confirmed above results. The ROC AUC values of about 87% of these core targets of TCF extracts was greater than 0.5 in the two GEO chips of AD, especially 10 targets with ROC AUC values greater than 0.7, such as BCL2, CASP7, NFKBIA, HMOX1, CDK2, LDLR, RELA, and CCL2, which mainly referred to neuron apoptosis, response to oxidative stress and inflammation, fibroblast proliferation, etc.Conclusions:The TCF extracts have diverse active compounds that can act on the diagnostic genes of AD, which deserve further in-depth study.

Comprehensive insight into the molecular interaction of rutin with human transferrin: Implication of natural compounds in neurodegenerative diseases

Neurodegeneration, a process of irreversible neuronal damage, is characterized by a damaged neuronal structure and function. The interplay between various proteins maintains homeostasis of essential metals in the brain, shielding neurons from degeneration; human transferrin (Htf) is essential in maintaining iron homeostasis. Any disruption in iron homeostasis results in the development of neurodegenerative diseases (NDs) and their pathology, mainly Alzheimer's disease (AD). Rutin is a known compound for its neuroprotective effects. In this work, we deciphered the binding of rutin with Htf in a bid to understand the interaction mechanism. The results of fluorescence and UV-vis spectroscopy demonstrated strong interaction between rutin and Htf. The enthalpy change (∆H°) and entropy change (∆S°) analysis demonstrated hydrophobic interactions as the prevalent forces. The binding mechanism of rutin was further assessed atomistically by molecular docking and extensive 200 ns molecular dynamic simulation (MD) studies; molecular docking showed binding of rutin within Htf's binding pocket. MD results suggested that binding of rutin to Htf does not cause significant structural switching or disruption of the protein's native packing. Overall, the study deciphers the binding of rutin with hTf, delineating the binding mechanism and providing a platform to use rutin in NDs therapeutics.

The role of natural flavonoids on neuroinflammation as a therapeutic target for Alzheimer's disease: a narrative review

Alzheimer's disease is a neurodegenerative disease that affects a large proportion of older adult people and is characterized by memory loss, progressive cognitive impairment, and various behavioral disturbances. Although the pathological mechanisms underlying Alzheimer's disease are complex and remain unclear, previous research has identified two widely accepted pathological characteristics: extracellular neuritic plaques containing amyloid beta peptide, and intracellular neurofibrillary tangles containing tau. Furthermore, research has revealed the significant role played by neuroinflammation over recent years. The inflammatory microenvironment mainly consists of microglia, astrocytes, the complement system, chemokines, cytokines, and reactive oxygen intermediates; collectively, these factors can promote the pathological process and aggravate the severity of Alzheimer's disease. Therefore, the development of new drugs that can target neuroinflammation will be a significant step forward for the treatment of Alzheimer's disease. Flavonoids are plant-derived secondary metabolites that possess various bioactivities. Previous research found that multiple natural flavonoids could exert satisfactory treatment effects on the neuroinflammation associated with Alzheimer's disease. In this review, we describe the pathogenesis and neuroinflammatory processes of Alzheimer's disease, and summarize the effects and mechanisms of 13 natural flavonoids (apigenin, luteolin, naringenin, quercetin, morin, kaempferol, fisetin, isoquercitrin, astragalin, rutin, icariin, mangiferin, and anthocyanin) derived from plants or medicinal herbs on neuroinflammation in Alzheimer's disease. As an important resource for the development of novel compounds for the treatment of critical diseases, it is essential that we focus on the exploitation of natural products. In particular, it is vital that we investigate the effects of flavonoids on the neuroinflammation associated with Alzheimer's disease in greater detail.

Therapeutic considerations of bioactive compounds in Alzheimer's disease and Parkinson's disease: Dissecting the molecular pathways

Leading neurodegenerative diseases Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by the impairment of memory and motor functions, respectively. Despite several breakthroughs, there exists a lack of disease-modifying treatment strategies for these diseases, as the available drugs provide symptomatic relief and bring along side effects. Bioactive compounds are reported to bear neuroprotective properties with minimal toxicity, however, a detailed elucidation of their modes of neuroprotection is lacking. The review elucidates the neuroprotective mechanism(s) of some of the major phyto-compounds in pre-clinical and clinical studies of AD and PD to understand their potential in combating these diseases. Curcumin, eugenol, resveratrol, baicalein, sesamol and so on have proved efficient in countering the pathological hallmarks of AD and PD. Curcumin, resveratrol, caffeine and so on have reached the clinical phases of these diseases, while aromadendrin, delphinidin, cyanidin and xanthohumol are yet to be extensively explored in pre-clinical phases. The review highlights the need for extensive investigation of these compounds in the clinical stages of these diseases so as to utilize their disease-modifying abilities in the real field of treatment. Moreover, poor pharmacokinetic properties of natural compounds are constraints to their therapeutic yields and this review suggests a plausible contribution of nanotechnology in overcoming these limitations.

Phytochemical and Nutraceutical Screening of Ethanol and Ethyl Acetate Phases of Romanian Galium verum Herba (Rubiaceae)

Galium species are used worldwide for their antioxidant, antibacterial, antifungal, and antiparasitic properties. Although this plant has demonstrated its antitumor properties on various types of cancer, its biological activity on cutaneous melanoma has not been established so far. Therefore, the present study was designed to investigate the phytochemical profile of two extracts of G. verum L. herba (ethanolic and ethyl acetate) as well as the biological profile (antioxidant, antimicrobial, and antitumor effects) on human skin cancer. The extracts showed similar FT-IR phenolic profiles (high chlorogenic acid, isoquercitrin, quercitrin, and rutin), with high antioxidant capacity (EC50 of ethyl acetate phase (0.074 ± 0.01 mg/mL) > ethanol phase (0.136 ± 0.03 mg/mL)). Both extracts showed antimicrobial activity, especially against Gram-positive Streptococcus pyogenes and Staphylococcus aureus bacilli strains, the ethyl acetate phase being more active. Regarding the in vitro antitumor test, the results revealed a dose-dependent cytotoxic effect against A375 melanoma cell lines, more pronounced in the case of the ethyl acetate phase. In addition, the ethyl acetate phase stimulated the proliferation of human keratinocytes (HaCaT), while this effect was not evident in the case of the ethanolic phase at 24 h post-stimulation. Consequently, G. verum l. could be considered a promising phytocompound for the antitumor approach of cutaneous melanoma.

Research Progress on Natural Plant Molecules in Regulating the Blood-Brain Barrier in Alzheimer's Disease

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder. With the aging population and the continuous development of risk factors associated with AD, it will impose a significant burden on individuals, families, and society. Currently, commonly used therapeutic drugs such as Cholinesterase inhibitors, N-methyl-D-aspartate antagonists, and multiple AD pathology removal drugs have been shown to have beneficial effects on certain pathological conditions of AD. However, their clinical efficacy is minimal and they are associated with certain adverse reactions. Furthermore, the underlying pathological mechanism of AD remains unclear, posing a challenge for drug development. In contrast, natural plant molecules, widely available, offer multiple targeting pathways and demonstrate inherent advantages in modifying the typical pathologic features of AD by influencing the blood-brain barrier (BBB). We provide a comprehensive review of recent in vivo and in vitro studies on natural plant molecules that impact the BBB in the treatment of AD. Additionally, we analyze their specific mechanisms to offer novel insights for the development of safe and effective targeted drugs as well as guidance for experimental research and the clinical application of drugs for the prevention and treatment of AD.

Inflammatory signaling pathways in the treatment of Alzheimer's disease with inhibitors, natural products and metabolites (Review)

The intricate nature of Alzheimer's disease (AD) pathogenesis poses a persistent obstacle to drug development. In recent times, neuroinflammation has emerged as a crucial pathogenic mechanism of AD, and the targeting of inflammation has become a viable approach for the prevention and management of AD. The present study conducted a comprehensive review of the literature between October 2012 and October 2022, identifying a total of 96 references, encompassing 91 distinct pharmaceuticals that have been investigated for their potential impact on AD by inhibiting neuroinflammation. Research has shown that pharmaceuticals have the potential to ameliorate AD by reducing neuroinflammation mainly through regulating inflammatory signaling pathways such as NF‑κB, MAPK, NLRP3, PPARs, STAT3, CREB, PI3K/Akt, Nrf2 and their respective signaling pathways. Among them, tanshinone IIA has been extensively studied for its anti‑inflammatory effects, which have shown significant pharmacological properties and can be applied clinically. Thus, it may hold promise as an effective drug for the treatment of AD. The present review elucidated the inflammatory signaling pathways of pharmaceuticals that have been investigated for their therapeutic efficacy in AD and elucidates their underlying mechanisms. This underscores the auspicious potential of pharmaceuticals in ameliorating AD by impeding neuroinflammation.

Binding mechanism and biological effects of flavone DYRK1A inhibitors for the design of new antidiabetics

The selective inhibition of kinases from the diabetic kinome is known to promote the regeneration of beta cells and provide an opportunity for the curative treatment of diabetes. The effect can be achieved by carefully tailoring the selectivity of inhibitor toward a particular kinase, especially DYRK1A, previously associated with Down syndrome and Alzheimer's disease. Recently DYRK1A inhibition has been shown to promote both insulin secretion and beta cells proliferation. Here, we show that commonly available flavones are effective inhibitors of DYRK1A. The observed biochemical activity of flavone compounds is confirmed by crystal structures solved at 2.06 Å and 2.32 Å resolution, deciphering the way inhibitors bind in the ATP-binding pocket of the kinase, which is driven by the arrangement of hydroxyl moieties. We also demonstrate antidiabetic properties of these biomolecules and prove that they could be further improved by therapy combined with TGF-β inhibitors. Our data will allow future structure-based optimization of the presented scaffolds toward potent, bioavailable and selective anti-diabetic drugs.

Exploring the therapeutic potential of natural compounds for Alzheimer's disease: Mechanisms of action and pharmacological properties

Alzheimer's Disease (AD) is a global public health priority characterized by high mortality rates in adults and an increasing prevalence in aging populations worldwide. Despite significant advancements in comprehending the pathogenesis of AD since its initial report in 1907, there remains a lack of effective curative or preventive measures for the disease. In recent years, natural compounds sourced from diverse origins have garnered considerable attention as potential therapeutic agents for AD, owing to their anti-inflammatory, antioxidant, and neuroprotective properties. This review aims to consolidate the therapeutic effects of natural compounds on AD, specifically targeting the reduction of β-amyloid (Aβ) overproduction, anti-apoptosis, autophagy, neuroinflammation, oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Notably, the identified compounds exhibiting these effects predominantly originate from plants. This review provides valuable insights into the potential of natural compounds as a reservoir of novel therapeutic agents for AD, thereby stimulating further research and contributing to the development of efficacious treatments for this devastating disease.

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.

Toxicity of Copper and Zinc alone and in combination in Caenorhabditis elegans model of Huntington's disease and protective effects of rutin

Copper (Cu) and Zinc (Zn) are required in small concentrations for metabolic functions, but are also toxic. There is a great concern about soil pollution by heavy metals, which may exposure the population to these toxicants, either by inhalation of dust or exposure to toxicants through ingestion of food derived from contaminated soils. In addition, the toxicity of metals in combination is questionable, as soil quality guidelines only assess them separately. It is well known that metal accumulation is often found in the pathologically affected regions of many neurodegenerative diseases, including Huntington's disease (HD). HD is caused by an autosomal dominantly inherited CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. This results in the formation of a mutant huntingtin (mHTT) protein with an abnormally long polyglutamine (polyQ) repeat. The pathology of HD results in loss of neuronal cells, motor changes, and dementia. Rutin is a flavonoid found in various food sources, and previous studies indicate it has protective effects in HD models and acts as a metal chelator. However, further studies are needed to unravel its effects on metal dyshomeostasis and to discern the underlying mechanisms. In the present study, we investigated the toxic effects of long-term exposure to copper, zinc, and their mixture, and the relationship with the progression of neurotoxicity and neurodegeneration in a C. elegans-based HD model. Furthermore, we investigated the effects of rutin post metal exposure. Overall, we demonstrate that chronic exposure to the metals and their mixture altered body parameters, locomotion, and developmental delay, in addition to increasing polyQ protein aggregates in muscles and neurons causing neurodegeneration. We also propose that rutin has protective effects acting through mechanisms involving antioxidant and chelating properties. Altogether, our data provides new indications about the higher toxicity of metals in combination, the chelating potential of rutin in the C. elegans model of HD and possible strategies for future treatments of neurodegenerative diseases caused by the aggregation of proteins related to metals.

Brain-targeted lycopene-loaded microemulsion modulates neuroinflammation, oxidative stress, apoptosis and synaptic plasticity in β-amyloid-induced Alzheimer's disease mice

OBJECTIVES

β-Amyloid protein (Aβ) plays pivotal roles in pathogenesis of Alzheimer's disease (AD) and triggers various pathophysiological events. Lycopene is a promising neuroprotector with multiple bioactivities, while its bioavailability is limited. Lycopene-loaded microemulsion (LME) possessing superior bioavailability and brain-targeting efficiency was developed in our previous study. In this investigation, we aimed to comprehensively evaluate its neuroprotective effects and underlying mechanisms using intracerebroventricular (ICV) Aβ_1-42 injection mice.

METHODS

Mice were assigned to the Sham, Aβ, Aβ + LME and Aβ + lycopene dissolved in olive oil (LOO) groups. ICV Aβ_1-42 administration was performed, followed by oral gavage of brain-targeted LME or conventional LOO formulation for 3 weeks. Brain samples were harvested for immunohistochemistry, biochemical assays and western blotting analyses.

RESULTS

Our findings verified Aβ-induced neurotoxicity on neuroinflammation, oxidative stress, apoptosis, Aβ metabolisms and synaptic plasticity. LME supplementation dramatically attenuated astrocytosis and microgliosis, decreased malondialdehyde production and rescued antioxidant capacities, normalized apoptotic parameters and alleviated neuronal loss, inhibited amyloidogenic processing and activated non-amyloidogenic pathway, together with upregulating synaptic protein expressions and restoring synaptic plasticity. Nevertheless, most of these phenomena were not observed for mice treated with LOO, implying that LME showed significantly higher therapeutic efficacy against Aβ injury.

DISCUSSION

In summary, brain-targeted LME could exert neuroprotective function via suppressing a series of cascades triggered by Aβ aggregates, thus ameliorating Aβ neurotoxicity and associated abnormalities. Given this, LME may serve as an attractive candidate for AD prevention and treatment, and superiority of brain-targeting delivery is highlighted.

Hesperidin methylchalcone (HMC) hinders amyloid-β induced Alzheimer's disease by attenuating cholinesterase activity, macromolecular damages, oxidative stress and apoptosis via regulating NF-κB and Nrf2/HO-1 pathways

Phytocompounds therapy has recently emerged as an effective strategy to treat Alzheimer's disease. Herein, the protective effect of hesperidin methylchalcone (HMC) was evaluated through Alzheimer's disease models of Neuro-2a cells and Wistar rats. The in vitro results showed that HMC possesses significant ability to inhibit the acetylcholinesterase enzyme and exhibiting anti-aggregation and disaggregation properties. Furthermore, HMC could protect the Neuro-2a cells against Aβ-induced neurotoxicity. Simultaneously, HMC treatment significantly improved the cognitive deficits caused by Aβ-peptide on spatial memory in Wistar rats. HMC significantly enhanced the cholinergic effects by inhibiting AChE, BuChE, β-secretase activity, caspase-3 activity, and attenuating macromolecular damages and apoptosis. Notably, HMC reduced the Aβ-induced oxidative stress by activating the antioxidative defence enzymes. In addition, the HMC treatment suppressed the expression of immunocytokines such as p-NF-κB p65, p-IκBα, induced by Aβ; whereas upregulating Nrf2, HO-1 in brain homogenate. These results suggest that HMC could attenuate Aβ-induced neuroinflammation in brain via suppressing NF-κB signalling pathway and activating the Nrf2/HO-1 pathway, thereby improving memory and cognitive impairments in Wistar rats. Overall, the present study reports that HMC can act as a potent candidate with multi-faceted neuroprotective potential against Aβ-induced memory dysfunction in Wistar rats for the treatment of Alzheimer's disease.

Inhibition of ferroptosis through regulating neuronal calcium homeostasis: An emerging therapeutic target for Alzheimer's disease

Alzheimer's disease (AD), a chronic and progressive neurodegenerative disease, generates a serious threat to the health of the elderly. The AD brain is microscopically characterized by amyloid plaques and neurofibrillary tangles. There are still no effective therapeutic drugs to restrain the progression of AD though much attention has been paid to exploit AD treatments. Ferroptosis, a type of programmed cell death, has been reported to promote the pathological occurrence and development of AD, and inhibition of neuronal ferroptosis can effectively improve the cognitive impairment of AD. Studies have shown that calcium (Ca²⁺) dyshomeostasis is closely related to the pathology of AD, and can drive the occurrence of ferroptosis through several pathways, such as interacting with iron, and regulating the crosstalk between endoplasmic reticulum (ER) and mitochondria. This paper mainly reviews the roles of ferroptosis and Ca²⁺ in the pathology of AD, and highlights that restraining ferroptosis through maintaining the homeostasis of Ca²⁺ may be an innovative target for the treatment of AD.

Structural fingerprinting of pleiotropic flavonoids for multifaceted Alzheimer's disease

Alzheimer's disease has emerged as one of the most challenging neurodegenerative diseases associated with dementia, loss of cognitive functioning and memory impairment. Despite enormous efforts to identify disease modifying technologies, the repertoire of currently approved drugs consists of a few symptomatic candidates that are not capable of halting disease progression. Moreover, these single mechanism drugs target only a small part of the pathological cascade and do not address most of the etiological basis of the disease. Development of therapies that are able to simultaneously tackle all the multiple interlinked causative factors such as amyloid protein aggregation, tau hyperphosphorylation, cholinergic deficit, oxidative stress, metal dyshomeostasis and neuro-inflammation has become the focus of intensive research in this domain. Flavonoids are natural phytochemicals that have demonstrated immense potential as medicinal agents due to their multiple beneficial therapeutic effects. The polypharmacological profile of flavonoids aligns well with the multifactorial pathological landscape of Alzheimer's disease, making them promising candidates to overcome the challenges of this neurodegenerative disorder. This review presents a detailed overview of the pleiotropic biology of flavonoids favourable for Alzheimer therapeutics and the structural basis for these effects. Structure activity trends for several flavonoid classes such as flavones, flavonols, flavanones, isoflavones, flavanols and anthocyanins are comprehensively analyzed in detail and presented.

A Review on Phyto-Therapeutic Approaches in Alzheimer's Disease

Neurodegenerative diseases occur due to progressive and sometimes irreversible loss of function and death of nerve cells. A great deal of effort is being made to understand the pathogenesis of neurodegenerative diseases. In particular, the prevalence of Alzheimer's disease (AD) is quite high, and only symptomatic therapy is available due to the absence of radical treatment. The aim of this review is to try to elucidate the general pathogenesis of AD, to provide information about the limit points of symptomatic treatment approaches, and to emphasize the potential neurologic effects of phytocompounds as new tools as therapeutic agents for disease prevention, retardation, and therapy. This survey also covers the notable properties of herbal compounds such as their effects on the inhibition of an enzyme called acetylcholinesterase, which has significant value in the treatment of AD. It has been proven that phytopharmaceuticals have long-term effects that could protect nervous system health, eliminate inflammatory responses, improve cognitive damage, provide anti-aging effects in the natural aging process, and alleviate dementia sequelae. Herbal-based therapeutic agents can afford many advantages and can be used as potentially as new-generation therapeutics or complementary agents with high compliance, fewer adverse effects, and lower cost in comparison to the traditional pharmaceutical agents in the fight against AD.

Progress in the development of naturally derived active metabolites-based drugs: Potential therapeutics for Alzheimer's disease

Alzheimer's disease (AD) is an extensive age-associated neurodegenerative disorder. In spite of wide-ranging progress in understanding the AD pathology for the past 50 years, clinical trials based on the hypothesis of amyloid-beta (Aβ) have reserved worsening particularly at late-stage human trials. Consequently, very few old drugs are presently used for AD with inadequate clinical consequences and various side effects. We focus on widespread pharmacological and beneficial principles for existing as well as future drugs. Multitargeting approaches by means of general antioxidant and anti-inflammatory mechanisms allied with particular receptor and/or enzyme-mediated actions in neuroprotection and neurodegeneration. The plant kingdom comprises a vast range of species with an incredible diversity of bioactive metabolites with diverse chemical scaffolds. In recent times, an increasing body of facts recommended the use of phytochemicals to decelerate AD's onset and progression. The definitive goal of AD investigation is to avert the onset of neurodegeneration, thereby allowing successful aging devoid of cognitive decline. At this point, we discussed the neurological protective role of natural products and naturally derived therapeutic agents for AD from various natural polyphenolic compounds and medicinal plants. In conclusion, medicinal plants act as a chief source of different bioactive constituents.

Mechanistic Insights into the Neuroprotective Potential of Sacred Ficus Trees

Ficus religiosa (Bo tree or sacred fig) and Ficus benghalensis (Indian banyan) are of immense spiritual and therapeutic importance. Various parts of these trees have been investigated for their antioxidant, antimicrobial, anticonvulsant, antidiabetic, anti-inflammatory, analgesic, hepatoprotective, dermoprotective, and nephroprotective properties. Previous reviews of Ficus mostly discussed traditional usages, photochemistry, and pharmacological activities, though comprehensive reviews of the neuroprotective potential of these Ficus species extracts and/or their important phytocompounds are lacking. The interesting phytocompounds from these trees include many bengalenosides, carotenoids, flavonoids (leucopelargonidin-3-O-β-d-glucopyranoside, leucopelargonidin-3-O-α-l-rhamnopyranoside, lupeol, cetyl behenate, and α-amyrin acetate), flavonols (kaempferol, quercetin, myricetin), leucocyanidin, phytosterols (bergapten, bergaptol, lanosterol, β-sitosterol, stigmasterol), terpenes (α-thujene, α-pinene, β-pinene, α-terpinene, limonene, β-ocimene, β-bourbonene, β-caryophyllene, α-trans-bergamotene, α-copaene, aromadendrene, α-humulene, alloaromadendrene, germacrene, γ-cadinene, and δ-cadinene), and diverse polyphenols (tannin, wax, saponin, leucoanthocyanin), contributing significantly to their pharmacological effects, ranging from antimicrobial action to neuroprotection. This review presents extensive mechanistic insights into the neuroprotective potential, especially important phytochemicals from F. religiosa and F. benghalensis. Owing to the complex pathophysiology of neurodegenerative disorders (NDDs), the currently existing drugs merely alleviate the symptoms. Hence, bioactive compounds with potent neuroprotective effects through a multitarget approach would be of great interest in developing pharmacophores for the treatment of NDDs.

Neuroprotective Effect of Artichoke-Based Nanoformulation in Sporadic Alzheimer’s Disease Mouse Model: Focus on Antioxidant, Anti-Inflammatory, and Amyloidogenic Pathways

The vast socio-economic impact of Alzheimer’s disease (AD) has prompted the search for new neuroprotective agents with good tolerability and safety profile. With its outstanding role as antioxidant and anti-inflammatory, alongside its anti-acetylcholinesterase activity, the artichoke can be implemented in a multi-targeted approach in AD therapy. Moreover, artichoke agricultural wastes can represent according to the current United Nations Sustainable Development goals an opportunity to produce medicinally valuable phenolic-rich extracts. In this context, the UPLC-ESI-MS/MS phytochemical characterization of artichoke bracts extract revealed the presence of mono- and di-caffeoylquinic acids and apigenin, luteolin, and kaempferol O-glycosides with remarkable total phenolics and flavonoids contents. A broad antioxidant spectrum was established in vitro. Artichoke-loaded, chitosan-coated, solid lipid nanoparticles (SLNs) were prepared and characterized for their size, zeta potential, morphology, entrapment efficiency, release, and ex vivo permeation and showed suitable colloidal characteristics, a controlled release profile, and promising ex vivo permeation, indicating possibly better physicochemical and biopharmaceutical parameters than free artichoke extract. The anti-Alzheimer potential of the extract and prepared SLNs was assessed in vivo in streptozotocin-induced sporadic Alzheimer mice. A great improvement in cognitive functions and spatial memory recovery, in addition to a marked reduction of the inflammatory biomarker TNF-α, β-amyloid, and tau protein levels, were observed. Significant neuroprotective efficacy in dentate Gyrus sub-regions was achieved in mice treated with free artichoke extract and to a significantly higher extent with artichoke-loaded SLNs. The results clarify the strong potential of artichoke bracts extract as a botanical anti-AD drug and will contribute to altering the future medicinal outlook of artichoke bracts previously regarded as agro-industrial waste.

Forest Biomass as a Promising Source of Bioactive Essential Oil and Phenolic Compounds for Alzheimer's Disease Therapy

Alzheimer’s disease (AD) is the most common neurodegenerative disorder affecting elderly people worldwide. Currently, there are no effective treatments for AD able to prevent disease progression, highlighting the urgency of finding new therapeutic strategies to stop or delay this pathology. Several plants exhibit potential as source of safe and multi-target new therapeutic molecules for AD treatment. Meanwhile, Eucalyptus globulus extracts revealed important pharmacological activities, namely antioxidant and anti-inflammatory properties, which can contribute to the reported neuroprotective effects. This review summarizes the chemical composition of essential oil (EO) and phenolic extracts obtained from Eucalyptus globulus leaves, disclosing major compounds and their effects on AD-relevant pathological features, including deposition of amyloid-β (Aβ) in senile plaques and hyperphosphorylated tau in neurofibrillary tangles (NFTs), abnormalities in GABAergic, cholinergic and glutamatergic neurotransmission, inflammation, and oxidative stress. In general, 1,8-cineole is the major compound identified in EO, and ellagic acid, quercetin, and rutin were described as main compounds in phenolic extracts from Eucalyptus globulus leaves. EO and phenolic extracts, and especially their major compounds, were found to prevent several pathological cellular processes and to improve cognitive function in AD animal models. Therefore, Eucalyptus globulus leaves are a relevant source of biological active and safe molecules that could be used as raw material for nutraceuticals and plant-based medicinal products useful for AD prevention and treatment.

Integrated comparative metabolomics and network pharmacology approach to uncover the key active ingredients of Polygonati rhizoma and their therapeutic potential for the treatment of Alzheimer’s disease

Alzheimer’s disease (AD) has become a worldwide disease affecting human health and resulting in a heavy economic burden on the healthcare system. Polygonati rhizoma (PR), a kind of traditional Chinese medicine (TCM), is known to improve learning and memory abilities. However, its AD-treating material basis and therapeutic potential for the treatment of AD have remained unclear. Therefore, the present study aimed to uncover the key active ingredients of PR and its therapeutic potential for the treatment of AD. First, we used comparative metabolomics to identify the potential key active ingredients in the edible and medicinal PR. Second, network pharmacology was used to decipher the effects and potential targets of key active ingredients in the PR for the treatment of AD, and molecular docking was further used to identify the binding ability of those active ingredients with AD-related target of AChE. The rate of acetylcholinesterase (AChE) inhibition, oxidative stress, neuroprotective effects, and anti-inflammatory activity were assessed in vitro to screen the potential active ingredients in the PR with therapeutic potential against AD. Finally, APPswe/PS1dE9 AD mice were used to screen the therapeutic components in the PR. Seven overlapping upregulated differential metabolites were identified as the key active ingredients, among which cafestol, isorhamnetin, and rutin have AChE inhibitory activity, anti-inflammatory activity, and neuroprotective effects in vitro validation assays. Furthermore, in vivo results showed that cafestol, isorhamnetin, and rutin displayed several beneficial effects in AD transgenic mice by reducing the number of Aβ-positive spots and the levels of inflammatory cytokines, inhibiting the AChE activity, and increasing the antioxidant levels. Each compound is involved in a different function in the early stages of AD. In conclusion, our results corroborate the current understanding of the therapeutic effects of PR on AD. In addition, our work demonstrated that the proposed network pharmacology-integrated comparative metabolomics strategy is a powerful way of identifying key active ingredients and mechanisms contributing to the pharmacological effects of TCM.

Z-Guggulsterone attenuates cognitive defects and decreases neuroinflammation in APPswe/PS1dE9 mice through inhibiting the TLR4 signaling pathway

Growing evidence indicates that inflammatory damage is implicated in the pathogenesis of Alzheimer's disease (AD). Z-Guggulsterone (Z-GS) is a natural steroid, which is extracted from Commiphora mukul and has anti-inflammatory effects in vivo and in vitro. In the present study, we investigated the disease-modifying effects of chronic Z-GS administration on the cognitive and neuropathological impairments in the transgenic mouse models of AD. We found that chronic Z-GS administration prevented learning and memory deficits in the APPswe/PS1dE9 mice. In addition, Z-GS treatment significantly decreased cerebral amyloid-β (Aβ) levels and plaque burden via inhibiting amyloid precursor protein (APP) processing by reducing beta-site APP cleaving enzyme 1 (BACE1) expression in the APPswe/PS1dE9 mice. We also found that Z-GS treatment markedly alleviated neuroinflammation and reduced synaptic defects in the APPswe/PS1dE9 mice. Furthermore, the activated TLR4/NF-κB signaling pathways in APPswe/PS1dE9 mice were remarkably inhibited by Z-GS treatment, which was achieved via suppressing the phosphorylation of JNK. Collectively, our data demonstrate that chronic Z-GS treatment restores cognitive defects and reverses multiple neuropathological impairments in the APPswe/PS1dE9 mice. This study provides novel insights into the neuroprotective effects and neurobiological mechanisms of Z-GS on AD, indicating that Z-GS is a promising disease-modifying agent for the treatment of AD.

Protective Effects of Zingerone Against Depression-Like Behavior and Biochemical Changes in Chronic Stressed Rats: Antioxidant Effects

Ginger contains zingerone, an active constituent possessing antioxidant and neuroprotective properties. The present study was designed to explore the efficacy of the bioactive compound, zingerone, for treating behavioral and biochemical alterations in rats exposed to chronic restraint stress (CRS). Female Wistar rats were administered zingerone (25, 50, and 100 mg/kg p.o.) once daily for a period of 28 days while being exposed to CRS (6 h/day). Our results indicated that the stressed animals depicted depression-like behavior (reduced sucrose preference and increased immobility time) associated with increased lipid peroxidation (LPO) (cortex), decreased catalase (CAT) (hippocampus and cortex), and increased superoxide dismutase (SOD) (hippocampus and cortex). In addition, metabolic alterations were characterized by hyperglycemia and increased glycosylated hemoglobin in the CRS rats. However, no alterations were observed for learning and memory and in the levels of reduced glutathione. Repeated zingerone administration significantly reversed depression-like behavior elicited by CRS in rats. Furthermore, a significant antioxidant effect was exhibited by zingerone, as shown by decreased LPO and enhanced activity of SOD and CAT in chronically stressed rats. The findings of our study demonstrated that zingerone possesses protective actions against chronic stress-induced depressive-like behavioral, biochemical, and metabolic alterations and that its underlying mechanism may be attributed to its antioxidant properties. The results also signify its pharmacological and possible nutritional importance.

Multifunctional icariin and tanshinone IIA co-delivery liposomes with potential application for Alzheimer's disease

The blood-brain barrier (BBB) is a protective barrier for brain safety, but it is also a major obstacle to the delivery of drugs to the cerebral parenchyma such as the hippocampus, hindering the treatment of central nervous system diseases such as Alzheimer's disease (AD). In this work, an anti-AD brain-targeted nanodrug delivery system by co-loading icariin (ICA) and tanshinone IIA (TSIIA) into Aniopep-2-modified long-circulating (Ang2-ICA/TSIIA) liposomes was developed. Low-density lipoprotein receptor-related protein-1 (LRP1) was a receptor overexpressed on the BBB. Angiopep-2, a specific ligand of LRP1, exhibited a high binding efficiency with LRP1. Additionally, ICA and TSIIA, drugs with neuroprotective effects are loaded into the liposomes, so that the liposomes not only have an effective BBB penetration effect, but also have a potential anti-AD effect. The prepared Ang2-ICA/TSIIA liposomes appeared narrow dispersity and good stability with a diameter of 110 nm, and a round morphology. Cell uptake observations, BBB models in vitro, and imaging analysis in vivo showed that Ang2-ICA/TSIIA liposomes not only penetrate the BBB through endocytosis, but also accumulate in N2a cells or brain tissue. The pharmacodynamic analysis in vivo demonstrated that Ang2-ICA/TSIIA liposomes could improve AD-like pathological features in APP/PS1 mice, including inhibiting neuroinflammation and oxidative stress, reducing apoptosis, protecting neurons, and improving cognitive function. Therefore, Ang2-ICA/TSIIA liposomes are considered a potentially effective therapeutic strategy for AD.

Computer-aided identification of cholinergic and monoaminergic inhibitory flavonoids from Hibiscus sabdariffa L

BACKGROUND

The reduced levels of acetylcholine and dopamine lead to Alzheimer's disease AD and Parkinson disease PD, respectively, due to the action of cholinesterase and monoamine oxidase B.

METHODS

Therapeutic options for AD and PD involve respective cholinergic and monoaminergic inhibitors, and considering the adverse outcomes of cholinergic- and monoaminergic- inhibitory therapeutics, phytoconstituents may be promising alternatives. Reports have shown that different extracts of the calyx of Hibiscus sabdariffa exhibit anticholinesterase and monoamine oxidase B inhibitory properties with potential to delay and prevent the development of AD and PD. However, there is limited knowledge on the multitarget cholinergic and monoaminergic inhibitory activities of individual compounds in this plant. Computational methods were used to identify the specific compounds responsible for the observed cholinergic and monoaminergic inhibitory activities of the H. sabdariffa calyx extracts.

RESULTS

Results confirm that three flavonoids: delphinidin-3-sambubioside, kaempferol-3-O-rutinoside and quercetin-3-rutinoside showed strong binding affinity with acetylcholinesterase, butyrylcholinesterase and monoamine oxidase B while the observed stability of the ligands-enzymes complexes over the MD simulation time suggests their cholinergic and monoaminergic inhibitory properties.

CONCLUSION

The three flavonoids may be responsible for the reported anticholinergic and monoaminergic inhibitory potentials of H. sabdariffa extracts and could be enlisted as multi-target inhibitory agents for cholinesterases and monoamine oxidase B.

Cortex metabolome and proteome analysis reveals chronic arsenic exposure via drinking water induces developmental neurotoxicity through hnRNP L mediated mitochondrial dysfunction in male rats

Lots of people are at the risk of arsenic-contaminated drinking water. Arsenic exposure was confirmed to be closely linked to neurocognitive deficits, particularly during childhood. The multi-omics approaches are known be well suitable for toxicological research. Thus, this study aimed to explore the molecular mechanisms of arsenic-induced learning and memory function impairments through the integrative proteome and metabolome analysis of cortex in rats. The weaned rats were exposed to arsenic-contaminated drinking water for six months to mimic the developmental exposure. 220 differential proteins and 19 differential metabolites were identified in the cortex, and nine potential biomarkers were found to be related to impaired Morris water maze (MWM) indicators. Chronic arsenic exposure affected the cognitive function by inducing the overproduction of amyloid-β (Aβ) peptides and the redox imbalance in the mitochondria. Glycolysis and tricarboxylic acid (TCA) cycle enhancement driven by the increased heterogeneous nuclear ribonucleoprotein L (hnRNP L) is a low-dose protective mechanism against arsenic-induced ATP deficiency and oxidative stress. Moreover, apoptosis is another important pathway of arsenic-induced neurotoxicity. This study provides new evidence about the alterations of proteins and metabolites in the cortex of the exposed rats under arsenic toxicity. These findings suggest hnRNP L could be a potential target for the treatment of arsenic-induced neurotoxicity.