Putative Role of Red Wine Polyphenols against Brain Pathology in Alzheimer's and Parkinson's Disease

Investigating the effects of Thymus vulgaris essential oil, Allium cepa extract, and their active compounds (thymol and quercetin) on expression profile of genes related to Alzheimer's disease in PC12 model cell

Thymus vulgaris and Allium cepa are plants with great medicinal importance. Thymol monoterpene and quercetin, which are present in these plants, have anti-Alzheimer's and antioxidant effects. The objectives of this research were investigating the effects of these compounds on the pathogenesis and progress of Alzheimer's disease in cells modeled by formaldehyde. MTT, flow cytometry, and RT-PCR were used to investigate the toxicity, survival rate and apoptosis of the cells, and the expression level of PP2A, GSK3, NMDAR, BACE1, and APP genes, respectively. Also, the total antioxidant capacity of the modeled cells was measured. The results showed that the two compounds as well as the plants extract and essential oil were able to increase the percentage of cell survival; among them, Thymus vulgaris essential oil had the greatest effect (93.55316 % in 48 h exposure). In addition, quercetin was able to reduce the rate of apoptosis in Alzheimer's cells (4.73 %) which was greater than the effects of other compounds. In general, the essential oil of Thymus vulgaris compared to thymol; and quercetin compared to Allium cepa extract showed more improving effects on the expression of genes involved in the disease. All four compounds increased the antioxidant capacity of the modeled cells compared to the control group, and these effects were almost equal between the compounds. According to the obtained results, both plants, especially Thymus vulgaris can be proposed as candidates to be included in the diet of Alzheimer's patients. In addition, polyphenols thymol and quercetin as derivates from the studied plants can be used in new drugs development for Alzheimer's disease, with greater safety than currently used drugs. These results are significant because most of the drug for Alzheimer's treatments such as cholinesterases (e.g. rivastigmine and donepezil) and memantine are chemically based and have many side effects.

Correlation between dietary factors and Parkinson's disease revealed by the analysis of Mendelian randomization

Background

The intricate interplay between dietary habits and the development of Parkinson's Disease (PD) has long been a subject of scientific inquiry. Mendelian Randomization (MR) emerges as a potent tool, harnessing genetic variants to infer causality in observational data. While evidence links diet to Parkinson's Disease (PD) etiology, a thorough MR exploration of dietary impacts on PD, particularly involving gut microbiota, is still emerging.

Methods

This research leverages the IEU Open GWAS project's vast GWAS database to address the knowledge gap in understanding diet's influence on PD, employing a diverse range of dietary variables. Our holistic dataset includes various foods like processed fava beans, bap, red wine, to cheese, reflecting a commitment to untangling dietary complexities in PD etiology. Advancing from initial dietary-PD associations, we innovatively explore the gut microbiota, focusing on Parabacteroides goldsteinii, in relation to bap intake and PD, employing MR. Utilizing weighted median, MR-Egger, and inverse variance weighting methods, we ensure rigorous causality assessments, meticulously mitigating pleiotropy and heterogeneity biases to uphold finding validity.

Results

Our findings indicate red wine (OR: 1.031; 95% CI 1.001-1.062; p = 0.044) and dried fruit consumption (OR: 2.019; 95% CI 1.052-3.875; p = 0.035) correlate with increased PD risk, whereas broad beans (OR: 0.967; 95% CI 0.939-0.996; p = 0.024) and bap intake (OR: 0.922; 95% CI 0.860-0.989; p = 0.023) show protective effects against PD. Employing MR, specifically the IVW method, revealed a significant inverse association between bap intake and gut microbiota, marked by an 8.010-fold decrease in Parabacteroides goldsteinii per standard deviation increase in bap intake (95% CI 1.005-63.818, p = 0.049). Furthermore, a connection between PD and Parabacteroides goldsteinii was observed (OR: 0.810; 95% CI 0.768-0.999; p = 0.049), suggesting a potential microbiota-mediated pathway in PD etiology.

Conclusion

Our study links dietary habits to PD risk, showing higher PD risk with red wine and dried fruit consumption, and a protective effect from broad beans and bap. Using MR, we found bap intake inversely correlates with Parabacteroides goldsteinii in the gut, suggesting bap influences microbiota. Further, higher Parabacteroides goldsteinii levels correlate with lower PD risk, highlighting a complex interplay of diet, gut microbiome, and neurological health. These insights shed light on potential dietary interventions for PD.

Impact of micronutrients and nutraceuticals on cognitive function and performance in Alzheimer's disease

Alzheimer's disease (AD) is a major global health problem today and is the most common form of dementia. AD is characterized by the formation of β-amyloid (Aβ) plaques and neurofibrillary clusters, leading to decreased brain acetylcholine levels in the brain. Another mechanism underlying the pathogenesis of AD is the abnormal phosphorylation of tau protein that accumulates at the level of neurofibrillary aggregates, and the areas most affected by this pathological process are usually the cholinergic neurons in cortical, subcortical, and hippocampal areas. These effects result in decreased cognitive function, brain atrophy, and neuronal death. Malnutrition and weight loss are the most frequent manifestations of AD, and these are also associated with greater cognitive decline. Several studies have confirmed that a balanced low-calorie diet and proper nutritional intake may be considered important factors in counteracting or slowing the progression of AD, whereas a high-fat or hypercholesterolemic diet predisposes to an increased risk of developing AD. Especially, fruits, vegetables, antioxidants, vitamins, polyunsaturated fatty acids, and micronutrients supplementation exert positive effects on aging-related changes in the brain due to their antioxidant, anti-inflammatory, and radical scavenging properties. The purpose of this review is to summarize some possible nutritional factors that may contribute to the progression or prevention of AD, understand the role that nutrition plays in the formation of Aβ plaques typical of this neurodegenerative disease, to identify some potential therapeutic strategies that may involve some natural compounds, in delaying the progression of the disease.

Butein Increases Resistance to Oxidative Stress and Lifespan with Positive Effects on the Risk of Age-Related Diseases in Caenorhabditis elegans

Butein is a flavonoid found in many plants, including dahlia, butea, and coreopsis, and has both antioxidant and sirtuin-activating activities. In light of the postulated role of free radicals in aging, we examined the effects of butein on aging and on genetic or nutritional models of age-related diseases in Caenorhabditis elegans. Butein showed radical scavenging activity and increased resistance to oxidative stress in Caenorhabditis elegans. The mean lifespan of Caenorhabditis elegans was significantly increased by butein, from 22.7 days in the untreated control to 25.0 days in the butein-treated group. However, the lifespan-extending effect of butein was accompanied by reduced production of progeny as a trade-off. Moreover, the age-related decline in motility was delayed by butein supplementation. Genetic analysis showed that the lifespan-extending effect of butein required the autophagic protein BEC-1 and the transcription factor DAF-16 to regulate stress response and aging. At the genetic level, expression of the DAF-16 downstream target genes hsp-16.2 and sod-3 was induced in butein-treated worms. Butein additionally exhibited a preventive effect in models of age-related diseases. In an Alzheimer's disease model, butein treatment significantly delayed the paralysis caused by accumulation of amyloid-beta in muscle, which requires SKN-1, not DAF-16. In a high-glucose-diet model of diabetes mellitus, butein markedly improved survival, requiring both SKN-1 and DAF-16. In a Parkinson's disease model, dopaminergic neurodegeneration was completely inhibited by butein supplementation and the accumulation of α-synuclein was significantly reduced. These findings suggest the use of butein as a novel nutraceutical compound for aging and age-related diseases.

Insights into the Neuroprotective Potential of Epicatechin: Effects against Aβ-Induced Toxicity in Caenorhabditis elegans

Medical therapies to avoid the progression of Alzheimer's disease (AD) are limited to date. Certain diets have been associated with a lower incidence of neurodegenerative diseases. In particular, the regular intake of foods rich in polyphenols, such as epicatechin (EC), could help prevent or mitigate AD progression. This work aims to explore the neuroprotective effects of EC using different transgenic strains of Caenorhabditis elegans, which express human Aβ1-42 peptides and contribute to elucidating the mechanisms involved in the effects of EC in AD. The performed assays indicate that this flavan-3-ol was able to reduce the signs of β-amyloid accumulation in C. elegans, improving motility and chemotaxis and increasing survival in transgenic strain peptide producers compared to nematodes not treated with EC. The neuroprotective effects exhibited by EC in C. elegans could be explained by the modulation of inflammation and stress-associated genes, as well as autophagy, microgliosis, and heat shock signaling pathways, involving the regulation of cpr-5, epg-8, ced-7, ZC239.12, and hsp-16 genes. Overall, the results obtained in this study support the protective effects of epicatechin against Aβ-induced toxicity.

Neurobehavioral impairments from chromium exposure: Insights from a zebrafish model and drug validation

We have developed a zebrafish model to explore the alterations in neurobehaviors resulting from both acute and chronic exposure to chromium (Cr). Zebrafish exposed to half (HC group: 19.7 mg/L) and a quarter (LC group: 9.85 mg/L) of the LD50 concentration of Cr for a span of 2 weeks exhibited aberrant locomotion, heightened anxiety, cognitive impairment, and reduced aggression - hallmark traits reminiscent of an Alzheimer's Disease (AD)-like syndrome. Furthermore, zebrafish exposed to an environmentally relevant concentration of Cr (EC group: 100 μg/L) for an extended period of 9 weeks exhibited behaviors comparable to those observed in the HC group. Moreover, the study investigated the neuroprotective effects of donepezil (Don), galantamine (Gal) and resveratrol (Res) drugs in response to neurobehavioral impairments induced by Cr (VI) exposure in zebrafish. Don and Res effectively protect the zebrafish from Cr (VI)-induced anxiety, and memory impairment. Furthermore, Cr (VI) exposure induced heightened oxidative stress while simultaneously diminishing antioxidant enzyme levels. Remarkably, these effects were counteracted in the drug-treated groups. Likewise, exposure to Cr (VI) led to an increase in the expression of genes linked to AD and neuroinflammation. Nevertheless, drug treatment reversed this effect in Cr (VI)-exposed fish. The results of our study highlight the potentials of zebrafish model in demonstrating neurobehavioral impairments induced by Cr (VI), thereby paving the way for its utilization in vivo neurobehaviors investigations and pharmaceutical screening.

The neuroprotective effect of quercetin nanoparticles in the therapy of neuronal damage stimulated by acrolein

A gradual loss of neuronal function or structure causes neurodegenerative disorders such as Parkinson's and Alzheimer's. Neurological damage might cause cell death. Acrolein is a high-risk air and water contaminant that causes neurodegenerative disorders. Quercetin has several strategies for treating neurodegenerative disorders but has limited bioavailability inside the body. One of the hypotheses offered to improve quercetin's bioavailability is to convert it into quercetin nanoparticles. This study aims to comprehend the immunohistochemical devastation that might arise in the cerebellum because of acrolein treatment. Furthermore, the protective and ameliorative roles of quercetin nanoparticles against oxidative stress and neurotoxicity induced in mice by acrolein were assessed. Ninety male albino rats weighing 120 to 200 g were used in the present investigation. The animals were split up into the following six groups: the control group, the acrolein-treated group: animals were given acrolein (3 mg/kg) for 30 days, quercetin nanoparticles treated group: animals were given quercetin nanoparticles (30 mg/kg) for 30 days. The administration of acrolein was found to be connected to immunohistochemical abnormalities in the cerebellum. Marked differences were observed in Bax, Bcl-2, TNF-α, and GFAP expressions in the cerebellum. Treatment of rats with quercetin nanoparticles either before or after treatment with acrolein has been found to preserve the cerebellum tissues from the toxic impacts and oxidative stress induced by acrolein. This may open the door to more nanomedicine studies and a new avenue for employing nanoparticles as a therapeutic intervention in neurodegenerative illnesses.

Valine conjugated polymeric nanocarriers for targeted co-delivery of rivastigmine and quercetin in rat model of Alzheimer disease

Multifunctional nanocarriers are increasingly promising for disease treatment aimed at finding effective therapy and overcoming barriers in drug delivery. Herein, valine conjugated chitosan (VLCS) was used for surface modification of nanocarriers (NCs) based on Poly (ε-caprolactone)-Poly (ethylene glycol)-Poly (ε-caprolactone) (PCL-PEG-PCL) triblock copolymers (NCs@VLCS). The nanocarriers were co-loaded with rivastigmine (RV) and quercetin (QT) to yield the final RV/QT-NCs@VLCS as a multifunctional nanocarrier for Alzheimer's disease (AD) treatment. The large amino acid transporter 1 (LAT-1) was selected for the direction of the NCs to the brain. The biocompatibility of the nanocarrier was studied in HEK-293 and SH-SY5Y cells and rats. The Morris water maze test demonstrated a faster regain of memory loss with RV/QT-NCs@VLCS compared to the other groups. Furthermore, RV/QT-NCs@VLCS and RV/QT-NCs improved GSH depletion induced by scopolamine (SCO), with RV/QT-NCs@VLCS having a superior effect. The real-time PCR analysis revealed that co-delivery of RV and QT by NCs@VLCS showed significantly higher efficacy than sole delivery of RV. RV/QT-NCs@VLCS treatment also modulated the expression of BDNF, ACHE, and TNF-α. The findings revealed that NCs@VLCS co-loaded with RV and QT, significantly increased efficacy relative to the single use of RV and could be considered a potent multifunctional drug delivery system for Alzheimer's treatment.

Purification and characterization of novel isoforms of the polyphenol oxidase from Malus domestica fruit pulp

Polyphenol oxidases (PPOs), belong to the group of oxidoreductases that are copper containing enzymes and are responsible for plant browning. PPOs are extensively distributed in plant kingdom and can oxidize wide range of aromatic compounds of industrial importance. The aim of this study was purification and characterization of PPO isoforms from the fruit pulp of Golden delicious apple. High performance liquid chromatography was used to purify the two novel isoforms of PPO and further their molecular weights (45 and 28 kDa) were determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified isoforms have optimum pH (6.5), optimum temperature (40°C), the Vmax (4.45 μM/min) and Km (74.21 mM) with catechol substrate. The N-terminal microsequences of both PPO isoforms were determined using a pulse liquid protein sequencer and found to be AKITFHG (28 kDa) and APGGG (45 kDa). Polyphenol oxidases are efficiently used in the pharmaceutical, paper and pulp, textiles and food industries. Recently, the PPOs have been used for bioremediation and in the development of biosensors.

Polyphenols and Their Impact on the Prevention of Neurodegenerative Diseases and Development

It is well known that neurodegenerative diseases' development and progression are accelerated due to oxidative stress and inflammation, which result in impairment of mitochondrial function, cellular damage, and dysfunction of DNA repair systems. The increased consumption of antioxidants can postpone the development of these disorders and improve the quality of patients' lives who have already been diagnosed with neurodegenerative diseases. Prolonging life span in developed countries contributes to an increase in the incidence ratio of chronic age-related neurodegenerative disorders, such as PD (Parkinson's disease), AD (Alzheimer's disease), or numerous forms of age-related dementias. Dietary supplementation with neuroprotective plant-derived polyphenols might be considered an important element of healthy aging. Some polyphenols improve cognition, mood, visual functions, language, and verbal memory functions. Polyphenols bioavailability differs greatly from one compound to another and is determined by solubility, degree of polymerization, conjugation, or glycosylation resulting from chemical structure. It is still unclear which polyphenols are beneficial because their potential depends on efficient transport across the BBB (blood-brain barrier), bioavailability, and stability in the CNS (central nervous system). Polyphenols improve brain functions by having a direct impact on cells and processes in the CNS. For a direct effect, polyphenolic compounds must be able to overcome the BBB and accumulate in brain tissue. In this review, the latest achievements in studies (animal models and clinical trials) on the effect of polyphenols on brain activity and function are described. The beneficial impact of plant polyphenols on the brain may be summarized by their role in increasing brain plasticity and related cognition improvement. As reversible MAO (monoamine oxidase) inhibitors, polyphenols are mood modulators and improve neuronal self-being through an increase in dopamine, serotonin, and noradrenaline amounts in the brain tissue. After analyzing the prohealth effects of various eating patterns, it was postulated that their beneficial effects result from synergistic interactions between individual dietary components. Polyphenols act on the brain endothelial cells and improve the BBB's integrity and reduce inflammation, thus protecting the brain from additional injury during stroke or autoimmune diseases. Polyphenolic compounds are capable of lowering blood pressure and improving cerebral blood flow. Many studies have revealed that a nutritional model based on increased consumption of antioxidants has the potential to ameliorate the cognitive impairment associated with neurodegenerative disorders. Randomized clinical trials have also shown that the improvement of cognitive functions resulting from the consumption of foods rich in flavonoids is independent of age and health conditions. For therapeutic use, sufficient quantities of polyphenols must cross the BBB and reach the brain tissue in active form. An important issue in the direct action of polyphenols on the CNS is not only their penetration through the BBB, but also their brain metabolism and localization. The bioavailability of polyphenols is low. The most usual oral administration also conflicts with bioavailability. The main factors that limit this process and have an effect on therapeutic efficacy are: selective permeability across BBB, gastrointestinal transformations, poor absorption, rapid hepatic and colonic metabolism, and systemic elimination. Thus, phenolic compounds have inadequate bioavailability for human applications to have any beneficial effects. In recent years, new strategies have been attempted in order to exert cognitive benefits and neuroprotective effects. Converting polyphenols into nanostructures is one of the theories proposed to enhance their bioavailability. The following nanoscale delivery systems can be used to encapsulate polyphenols: nanocapsules, nanospheres, micelles, cyclodextrins, solid lipid nanoparticles, and liposomes. It results in great expectations for the wide-scale and effective use of polyphenols in the prevention of neurodegenerative diseases. Thus far, only natural polyphenols have been studied as neuroprotectors. Perhaps some modification of the chemical structure of a given polyphenol may increase its neuroprotective activity and transportation through the BBB. However, numerous questions should be answered before developing neuroprotective medications based on plant polyphenols.

Targeting Nrf2 signaling pathway and oxidative stress by resveratrol for Parkinson's disease: an overview and update on new developments

Parkinson's disease (PD) as a prevalent neurodegenerative condition impairs motor function and is caused by the progressive deterioration of nigrostriatal dopaminergic (DAergic) neurons. The current therapy solutions for PD are ineffective because they could not inhibit the disease's progression and they even have adverse effects. Natural polyphenols, a group of phytochemicals, have been found to offer various health benefits, including neuroprotection against PD. Among these, resveratrol (RES) has neuroprotective properties owing to its capacity to protect mitochondria and act as an antioxidant. An increase in the formation of reactive oxygen species (ROS) leads to oxidative stress (OS), which is responsible for cellular damage resulting in lipid peroxidation, oxidative protein alteration, and DNA damage. In PD models, it's been discovered that RES pretreatment can diminish oxidative stress by boosting endogenous antioxidant status and directly scavenging ROS. Several studies have examined the involvement of RES in the modulation of the transcriptional factor Nrf2 in PD models because this protein recognizes oxidants and controls the antioxidant defense. In this review, we have examined the molecular mechanisms underlying the RES activity and reviewed its effects in both in vitro and in vivo models of PD. The gathered evidence herein showed that RES treatment provides neuroprotection against PD by reducing OS and upregulation of Nrf2. Moreover, in the present study, scientific proof of the neuroprotective properties of RES against PD and the mechanism supporting clinical development consideration has been described.

Endophytic Fusarium species, a unique bioresource for disaggregator of misfolded alpha-synuclein

Aggregation of α-synuclein into toxic oligomeric structures has been implicated in the pathogenesis of Parkinson's disease via several key stages of fibrillation, oligomerization, and aggregation. Disaggregation or prevention of aggregation has garnered a lot of attention as a therapeutic strategy to prevent or delay the progression of Parkinson's disease. It has been recently established that certain polyphenolic compounds and catechins present in plants and tea extracts exhibit the potential to inhibit the α-synuclein aggregation. However, their copious supply for therapeutic development is still unsolved. Herein, we report for the first time the disaggregation potential of α-synuclein by an endophytic fungus residing in tea leaves (Camellia sinensis). Briefly, a recombinant yeast expressing α-synuclein was used for pre-screening of 53 endophytic fungi isolated from tea using anti-oxidant activity as a marker for the disaggregation of the protein. One isolate #59CSLEAS exhibited 92.4% reduction in production of the superoxide ions, which were similar to the already established α-synuclein disaggregator, Piceatannol exhibiting 92.8% reduction. Thioflavin T assay further established that #59CSLEAS decreased the oligomerization of α-synuclein by 1.63-fold. Subsequently Dichloro-dihydro-fluorescein diacetate-based fluorescence assay exhibited a reduction in total oxidative stress in the recombinant yeast in the presence of fungal extract, thereby indicating the prevention of oligomerization. Oligomer disaggregation potential of the selected fungal extract was found to be 56.5% as assessed by sandwich ELISA assay. Using morphological as well as molecular methods, the endophytic isolate #59CSLEAS was identified as Fusarium sp. The sequence was submitted in the Genbank with accession number ON226971.1.

The Role of Dietary Antioxidants and Their Potential Mechanisms in Alzheimer’s Disease Treatment

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder associated with cognitive decline and characterized by amyloid-β plaques and neurofibrillary tau tangles. Although AD’s exact pathophysiology remains unclear, oxidative stress is known to play a role in the neurodegenerative process. Since no curative treatment exists, antioxidants represent a potential treatment for AD due to their ability to modulate oxidative stress. Therefore, this review aims to examine the impact of antioxidant supplementation and its potential mechanisms on cognitive function. The review primarily discusses research articles published between 2012 and 2022 reporting the results of clinical trials involving antioxidant supplementation on cognitive function in individuals with AD. Antioxidant supplementation included probiotics, selenium, melatonin, resveratrol, rosmarinic acid, carotenoids, curcumin, vitamin E, and coenzyme Q. While the studies included in this review did not provide much evidence for the beneficial role of antioxidant supplements on cognitive function in AD, the results varied from antioxidant to antioxidant and among trials examining the same antioxidant. Furthermore, many of the studies’ findings face several limitations, including short trial durations, small sample sizes, and a lack of diversity among study participants. As a result, more research is required to examine the impact of antioxidant supplementation on cognitive function in AD.

Bioactive self-healing hydrogel based on tannic acid modified gold nano-crosslinker as an injectable brain implant for treating Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is one of the most common long-term neurodegenerative diseases. Current treatments for PD are mostly based on surgery and medication because of the limitation and challenges in selecting proper biomaterials. In this study, an injectable bioactive hydrogel based on novel tannic acid crosslinker was developed to treat PD.

METHODS

The oxidized tannic acid modified gold nano-crosslinker was synthesized and used to effectively crosslink chitosan for preparation of the bioactive self-healing hydrogel. The crosslinking density, conductivity, self-healing ability, and injectability of the hydrogel were characterized. Abilities of the hydrogel to promote the proliferation and differentiation of neural stem cells (NSCs) were assessed in vitro. Anti-inflammatory property was analyzed on J774A.1 macrophages. The hydrogel was injected in the PD rat model for evaluation of the motor function recovery, electrophysiological performance improvement, and histological repair.

RESULTS

The hydrogel exhibited self-healing property and 34G (~ 80 μm) needle injectability. NSCs grown in the hydrogel displayed long-term proliferation and differentiation toward neurons in vitro. Besides, the hydrogel owned strong anti-inflammatory and antioxidative capabilities to rescue inflamed NSCs (~ 90%). Brain injection of the bioactive hydrogel recovered the motor function of PD rats. Electrophysiological measurements showed evident alleviation of irregular discharge of nerve cells in the subthalamic nucleus of PD rats administered with the hydrogel. Histological examination confirmed that the hydrogel alone significantly increased the density of tyrosine hydroxylase positive neurons and fibers as well as reduced inflammation, with a high efficacy similar to drug-loaded hydrogel.

CONCLUSION

The new bioactive hydrogel serves as an effective brain injectable implant to treat PD and a promising biomaterial for developing novel strategies to treat brain diseases.

Beneficial Effects of Red Wine Polyphenols on Human Health: Comprehensive Review

Polyphenols are secondary plant metabolites synthesized during the development of the grape berry as a response to stress conditions. They are important constituents in red wines that contribute to the sensory properties and antioxidant activity of wines. Due to the development of highly sophisticated analytical devices, it is now possible to characterize the structure of highly polymerized polyphenols and obtain a full polyphenol profile of red wines. Red wine polyphenols include the ones present in grapes as well as new polyphenol products formed during the winemaking process. Among them, the most important groups and their representatives are flavanols (catechin), stilbenes (trans-resveratrol), flavonols (quercetin) and hydroxybenzoic acids (gallic acid). It is known that polyphenols exhibit beneficial effects on human health, such as anti-inflammatory, anticarcinogenic and cardio-protective effects. Many studies have been conducted on the health effects of red wine polyphenols in cancer chemopreventive activities, neuroprotective effects and impact on cardiovascular diseases, gut microbiota in humans, etc. This review will provide major scientific findings on the impact of red wine polyphenols on human health as well as a review of polyphenols present in red wines and their main features.

Unveiling the Potential of Polyphenols as Anti-Amyloid Molecules in Alzheimer's Disease

Alzheimer's disease (AD) is a devastating neurodegenerative disease that mostly affects the elderly population. Mechanisms underlying AD pathogenesis are yet to be fully revealed, but there are several hypotheses regarding AD. Even though free radicals and inflammation are likely to be linked with AD pathogenesis, still amyloid-beta (Aβ) cascade is the dominant hypothesis. According to the Aβ hypothesis, a progressive buildup of extracellular and intracellular Aβ aggregates has a significant contribution to the AD-linked neurodegeneration process. Since Aβ plays an important role in the etiology of AD, therefore Aβ-linked pathways are mainly targeted in order to develop potential AD therapies. Accumulation of Aβ plaques in the brains of AD individuals is an important hallmark of AD. These plaques are mainly composed of Aβ (a peptide of 39-42 amino acids) aggregates produced via the proteolytic cleavage of the amyloid precursor protein. Numerous studies have demonstrated that various polyphenols (PPHs), including cyanidins, anthocyanins, curcumin, catechins and their gallate esters were found to markedly suppress Aβ aggregation and prevent the formation of Aβ oligomers and toxicity, which is further suggesting that these PPHs might be regarded as effective therapeutic agents for the AD treatment. This review summarizes the roles of Aβ in AD pathogenesis, the Aβ aggregation pathway, types of PPHs, and distribution of PPHs in dietary sources. Furthermore, we have predominantly focused on the potential of food-derived PPHs as putative anti-amyloid drugs.

The role of dietary antioxidants in type 2 diabetes and neurodegenerative disorders: An assessment of the benefit profile

Healthy diet is vital to cellular health. The human body succumbs to numerous diseases which afflict severe economic and psychological burdens on the patient and family. Oxidative stress is a possible crucial regulator of various pathologies, including type 2 diabetes and neurodegenerative diseases. It generates reactive oxygen species (ROS) that trigger the dysregulation of essential cellular functions, ultimately affecting cellular health and homeostasis. However, lower levels of ROS can be advantageous and are implicated in a variety of signaling pathways. Due to this dichotomy, the terms oxidative "eustress," which refers to a good oxidative event, and "distress," which can be hazardous, have developed. ROS affects multiple signaling pathways, leading to compromised insulin secretion, insulin resistance, and β-cell dysfunction in diabetes. ROS is also associated with increased mitochondrial dysfunction and neuroinflammation, aggravating neurodegenerative conditions in the body, particularly with age. Treatment includes drugs/therapies often associated with dependence, side effects including non-selectivity, and possible toxicity, particularly in the long run. It is imperative to explore alternative medicines as an adjunct therapy, utilizing natural remedies/resources to avoid all the possible harms. Antioxidants are vital components of our body that fight disease by reducing oxidative stress or nullifying the excess toxic free radicals produced under various pathological conditions. In this review, we focus on the antioxidant effects of components of dietary foods such as tea, coffee, wine, oils, and honey and the role and mechanism of action of these antioxidants in alleviating type 2 diabetes and neurodegenerative disorders. We aim to provide information about possible alternatives to drug treatments used alone or combined to reduce drug intake and encourage the consumption of natural ingredients at doses adequate to promote health and combat pathologies while reducing unwanted risks and side effects.

Gut microbiota, pathogenic proteins and neurodegenerative diseases

As the world's population ages, neurodegenerative diseases (NDs) have brought a great burden to the world. However, effective treatment measures have not been found to alleviate the occurrence and development of NDs. Abnormal accumulation of pathogenic proteins is an important cause of NDs. Therefore, effective inhibition of the accumulation of pathogenic proteins has become a priority. As the second brain of human, the gut plays an important role in regulate emotion and cognition functions. Recent studies have reported that the disturbance of gut microbiota (GM) is closely related to accumulation of pathogenic proteins in NDs. On the one hand, pathogenic proteins directly produced by GM are transmitted from the gut to the central center via vagus nerve. On the other hand, The harmful substances produced by GM enter the peripheral circulation through intestinal barrier and cause inflammation, or cross the blood-brain barrier into the central center to cause inflammation, and cytokines produced by the central center cause the production of pathogenic proteins. These pathogenic proteins can produced by the above two aspects can cause the activation of central microglia and further lead to NDs development. In addition, certain GM and metabolites have been shown to have neuroprotective effects. Therefore, modulating GM may be a potential clinical therapeutic approach for NDs. In this review, we summarized the possible mechanism of NDs caused by abnormal accumulation of pathogenic proteins mediated by GM to induce the activation of central microglia, cause central inflammation and explore the therapeutic potential of dietary therapy and fecal microbiota transplantation (FMT) in NDs.

Quercetin Nanoemulsion Ameliorates Neuronal Dysfunction in Experimental Alzheimer's Disease Model

Aluminum is the most abundant metal that can get admission to the human through several means that include our food, drinking water, cans, drugs, and deodorants, causing neurodegenerative diseases such as Alzheimer's disease (AD). The present study aims to evaluate the role of quercetin nanoemulsion (QCNE) in attenuating neuronal dysfunction in aluminum chloride (AlCl3)-induced experimental AD. All animals were classified into six groups including negative control group (I): received a vehicle; QC group: received intraperitoneal (IP) injection of QC; Alzheimer's group: received AlCl3 orally; treated group (I): received AlCl3 orally and IP injection of QC; treated group (II): received AlCl3 orally and QC orally; and treated group (III): received AlCl3 orally and IP injection of QCNE. At the end of the experimental period (30 days), the brain was used to study biochemical parameters (measurement of neurotransmitters (serotonin, dopamine, and norepinephrine), oxidant/antioxidant parameters (reduced glutathione, malondialdehyde, superoxide dismutase, and advanced oxidation protein product), and inflammatory markers (adiponectin, interleukin 1β, and plasma tumor necrosis factor-alpha)), while another part was for brain immune-histochemical analysis (study cyclooxygenases (COX-1 and COX-2)). Results showed that the mean value of oxidative stress markers was significantly increased in the AD group as well as the inflammatory biomarkers and all the study neurotransmitters, whereas these parameters were attenuated in treated groups, especially those that received QCNE. The immunohistochemistry findings confirm our results. Both approaches (QC and QCNE) succeeded in retracting the negative impact of AlCl3. Meanwhile, the effect of QCNE is more potent in mitigating the impact mediated by AlCl3 in treated animals. In conclusion, the treatment mainly by QCNE has huge potential in protecting against AlCl3-induced neuronal dysfunction, as shown in our results by the elevation of brain antioxidant/anti-inflammatory activities and neurotransmitter levels as well as mending of the histopathological changes in animal models.

Free radical biology in neurological manifestations: mechanisms to therapeutics interventions

Recent advancements and growing attention about free radicals (ROS) and redox signaling enable the scientific fraternity to consider their involvement in the pathophysiology of inflammatory diseases, metabolic disorders, and neurological defects. Free radicals increase the concentration of reactive oxygen and nitrogen species in the biological system through different endogenous sources and thus increased the overall oxidative stress. An increase in oxidative stress causes cell death through different signaling mechanisms such as mitochondrial impairment, cell-cycle arrest, DNA damage response, inflammation, negative regulation of protein, and lipid peroxidation. Thus, an appropriate balance between free radicals and antioxidants becomes crucial to maintain physiological function. Since the 1brain requires high oxygen for its functioning, it is highly vulnerable to free radical generation and enhanced ROS in the brain adversely affects axonal regeneration and synaptic plasticity, which results in neuronal cell death. In addition, increased ROS in the brain alters various signaling pathways such as apoptosis, autophagy, inflammation and microglial activation, DNA damage response, and cell-cycle arrest, leading to memory and learning defects. Mounting evidence suggests the potential involvement of micro-RNAs, circular-RNAs, natural and dietary compounds, synthetic inhibitors, and heat-shock proteins as therapeutic agents to combat neurological diseases. Herein, we explain the mechanism of free radical generation and its role in mitochondrial, protein, and lipid peroxidation biology. Further, we discuss the negative role of free radicals in synaptic plasticity and axonal regeneration through the modulation of various signaling molecules and also in the involvement of free radicals in various neurological diseases and their potential therapeutic approaches. The primary cause of free radical generation is drug overdosing, industrial air pollution, toxic heavy metals, ionizing radiation, smoking, alcohol, pesticides, and ultraviolet radiation. Excessive generation of free radicals inside the cell R1Q1 increases reactive oxygen and nitrogen species, which causes oxidative damage. An increase in oxidative damage alters different cellular pathways and processes such as mitochondrial impairment, DNA damage response, cell cycle arrest, and inflammatory response, leading to pathogenesis and progression of neurodegenerative disease other neurological defects.

Pharmacological effects and mechanisms of tannic acid

In recent years, increasing attention has been paid to the pharmacological efficacy of tannins. Tannic acid (TA), the simplest hydrolysable tannin that has been approved by the FDA as a safe food additive, is one of the most important components of these traditional medicines. Studies have shown that TA displays a wide range of pharmacological activities, such as anti-inflammatory, neuroprotective, antitumor, cardioprotective, and anti-pathogenic effects. Here, we summarize the known pharmacological effects and associated mechanisms of TA. We focus on the effect and mechanism of TA in various animal models of inflammatory disease and organ, brain, and cardiovascular injury. Moreover, we discuss the possible molecular targets and signaling pathways of TA, in addition to the pharmacological effects of TA-based nanoparticles and TA in combination with chemotherapeutic drugs.

The role of nutrition on Parkinson's disease: a systematic review

BACKGROUND

Parkinson's disease (PD) in elderly patients is the second most prevalent neurodegenerative disease. The pathogenesis of PD is associated with dopaminergic neuron degeneration of the substantia nigra in the basal ganglia, causing classic motor symptoms. Oxidative stress, mitochondrial dysfunction, and neuroinflammation have been identified as possible pathways in laboratory investigations. Nutrition, a potentially versatile factor from all environmental factors affecting PD, has received intense research scrutiny.

METHODS

A systematic search was conducted in the MEDLINE, EMBASE, and WEB OF SCIENCE databases from 2000 until the present. Only randomized clinical trials (RCTs), observational case-control studies, and follow-up studies were included.

RESULTS

We retrieved fifty-two studies that met the inclusion criteria. Most selected studies investigated the effects of malnutrition and the Mediterranean diet (MeDiet) on PD incidence and progression. Other investigations contributed evidence on the critical role of microbiota, vitamins, polyphenols, dairy products, coffee, and alcohol intake.

CONCLUSIONS

There are still many concerns regarding the association between PD and nutrition, possibly due to underlying genetic and environmental factors. However, there is a body of evidence revealing that correcting malnutrition, gut microbiota, and following the MeDiet reduced the onset of PD and reduced clinical progression. Other factors, such as polyphenols, polyunsaturated fatty acids, and coffee intake, can have a potential protective effect. Conversely, milk and its accessory products can increase PD risk. Nutritional intervention is essential for neurologists to improve clinical outcomes and reduce the disease progression of PD.

Pharmacological Mechanism of Shen Huang Chong Ji for Treating Alzheimer's Disease Based on Network Pharmacology and Experimental Validation

The traditional Chinese medicine (TCM) formula, Sheng Huang Chong Ji (SHCJ) is largely applied for treating Alzheimer's disease (AD), but not much is known regarding its active compounds, molecular targets, and mechanism of action. The current study aimed to predict the potential molecular mechanism of SHCJ against AD based on network pharmacology combined with in vitro validation. Using public databases, SHCJ's active compounds, their potential targets, and AD-related genes were screened, while Cytoscape Version 3.7.2 was used to build protein-protein interaction (PPI) and compound-disease-target (C-D-T) networks. Analysis of enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) terms was then carried out in R 4.0.2, including associated packages. Subsequently, molecular docking analysis was performed with AutoDock Vina 1.1.2, with intro experiments involving SH-SY5Y cells used to further investigate the mechanism of SHCJ against AD. Finally, a total of 56 active compounds of SHCJ and 192 SHCJ-AD-related targets were identified. Quercetin was identified as the top potential candidate agent. HSP90AA1, AKT1, and MAPK1 represent potential therapeutic targets. The PI3K-Akt signaling pathway potentially represents a core one mediating the effects of SHCJ against AD. Additionally, molecular docking analysis indicated that quercetin could combine well with AKT1 and multiple apoptosis-related target genes. During cell experiments, a significant increase in cell viability along with a decrease in Aβ _25-35-induced apoptosis was observed after treatment with SHCJ. Furthermore, SHCJ significantly increased the phosphorylation of PI3K and Akt while reversing Aβ _25-35-induced apoptosis-related protein expression downregulation.

Ferulic acid protects renal tubular epithelial cells against anoxia/reoxygenation injury mediated by AMPKα1

Anoxia/reoxygenation (A/R) injury causes dysfunction of rat renal tubular epithelial cells (NRK-52E), which is associated with excess reactive oxygen species (ROS) generation and eventually leads to apoptosis. Ferulic acid (FA), a phenolic acid, which is abundant in fruits and vegetables. FA possesses the properties of scavenging free radicals and cytoprotection against oxygen stress. In the study, the protective effects of FA against NRK-52E cells damage induced by A/R were explored and confirmed the role of AMP-activated protein kinaseα1 (AMPKα1). We found that after NRK-52E cells suffered A/R damage, FA pretreatment increased the cell viability and decreased LDH activity in culture medium in a concentration-dependent manner, the activities of endogenous antioxidant enzymes such as glutathione peroxidase, superoxide dismutase and catalase improved, intracellular ROS generation and malondialdehyde contents mitigated. In addition, pretreatment of 75 μM FA ameliorated mitochondrial dysfunction by A/R-injury and ultimately decreased apoptosis (25.3 ± 0.61 vs 12.1 ± 0.60), which was evidenced by preventing the release of cytochrome c from mitochondria to the cytoplasm. 75 μM FA pretreatment also significantly upregulated AMPKα1 expression (3.16 ± 0.18 folds) and phosphorylation (2.56 ± 0.13 folds). However, compound C, a specific AMPK inhibitor, significantly attenuated FA pretreatment's effects, as mentionedabove. These results firstly clarified that FA pretreatment attenuated NRK-52E cell damage induced by A/R via upregulating AMPKα1 expression and phosphorylation.

Agaricus Mushroom-Enriched Diets Modulate the Microbiota-Gut-Brain Axis and Reduce Brain Oxidative Stress in Mice

Neurodegenerative diseases pose a major problem for developed countries, and stress has been identified as one of the main risk factors in the development of these disorders. Here, we have examined the protective properties against brain oxidative stress of two diets supplemented with 5% (w/w) of Agaricus bisporus (white button mushroom) or Agaricus bisporus brunnescens (Portobello mushroom) in mice. These diets did not modify the weight gain of the animals when compared to those fed with a regular diet, even after feeding on them for 15 weeks. The long-term modification of the microbiota after 12 weeks on the diets was investigated. At the phylum level, there was a large increase of Verrucomicrobia and a reduction of Cyanobacteria associated with the mushroom diets. No changes were observed in the Firmicutes/Bacteroidetes ratio, whose stability is a marker for a healthy diet. At the family level, three groups presented significant variations. These included Akkermansiaceae and Tannerellaceae, which significantly increased with both diets; and Prevotellaceae, which significantly decreased with both diets. These bacteria participate in the generation of microbiota-derived short-chain fatty acids (SCFAs) and provide a link between the microbiota and the brain. Mice subjected to restraint stress showed an upregulation of Il-6, Nox-2, and Hmox-1 expression; a reduction in the enzymatic activities of catalase and superoxide dismutase; and an increase in lipid peroxidation in their brains. All these parameters were significantly prevented by feeding for 3 weeks on the Agaricus-supplemented diets. In summary, the supplementation of a healthy diet with Agaricus mushrooms may significantly contribute to prevent neurodegenerative diseases in the general population.

Protective effects of functional foods against Parkinson's disease: A narrative review on pharmacology, phytochemistry, and molecular mechanisms

In Persian Medicine (PM), PD (brain-based tremor) is a known CNS disorder with several therapeutic and preventive options. In their medical textbooks and pharmacopeias, Persian great scientists such as Rhazes (854-925 AD), Avicenna (980-1037 AD), and Jorjani (1042-1136 AD), have discussed pharmacological and nutritional strategies for the prevention, slowing progression, and treatment of PD. In the present study, we surveyed plant- and animal-based foods recommended by PM for the prevention and treatment of CNS-related tremors. In vivo and in-vitro pharmacological evidence supporting the beneficial effects of PM-recommended foods in prevention and alleviating PD, major active phytochemicals along with the relevant mechanisms of action were studied. Several PM plants possess potent antioxidant, antiinflammatory, and PD preventing properties. Garlic and allicin, cabbage and isothiocyanates, chickpea seed and its O-methylated isoflavones biochanin A and formononetin, cinnamon, and cinnamaldehyde, saffron and its crocin, crocetin, and safranal, black cumin and its thymoquinone, black pepper and piperine, pistachio and genistein and daidzein, and resveratrol are among the most effective dietary itemsagainst PD. They act through attenuating neurotoxin-induced memory loss and behavioral impairment, oxidative stress, and dopaminergic cell death. PM-recommended foods can help alleviate PD progression and also discovering and developing new neuroprotective anti-PD pharmaceuticals.

Animal models in the study of Alzheimer's disease and Parkinson's disease: A historical perspective

Alzheimer's disease and Parkinson's disease are two of the most prevalent and disabling neurodegenerative diseases globally. Both are proteinopathic conditions and while occasionally inherited, are largely sporadic in nature. Although the advances in our understanding of the two have been significant, they are far from complete and neither diagnosis nor the current practices in treatment and rehabilitation is adequately helpful. Animal models have historically found application as testing beds for novel therapeutics and continue to be valuable aids in pharmacological research. This review chronicles the development of those models in the context of Alzheimer's and Parkinson's disease, and highlights the shifting paradigms in studying two human-specific conditions in non-human organisms.

Chemical Composition and Polyphenolic Compounds of Red Wines: Their Antioxidant Activities and Effects on Human Health—A Review

Red wine, an alcoholic beverage is composed of a spectrum of complex compounds such as water, alcohol, glycerol, organic acid, carbohydrates, polyphenols, and minerals as well as volatile compounds. Major factors that affect the levels of phenolic compounds in red wines are the variety of grapes and the storage of the wines. Among the constituents of red wine, phenolic compounds play a crucial role in attributes including color and mouthfeel and confer beneficial properties on health. Most importantly, phenolic compounds such as flavanols, flavonols, flavanones, flavones, tannins, anthocyanins, hydroxycinnamic acids, hydroxybenzoic acids, and resveratrol can prevent the development of cardiovascular diseases, cancers, diabetes, inflammation, and some other chronic diseases.

Olive oil and wine as source of multi-target agents in the prevention of Alzheimer disease

Olive oil and wine are consumed daily worldwide and they constitute the fundamental pillars of the healthy Mediterranean diet. Polyphenolic compounds, naturally present in both olive oil and wine, are responsible for their beneficial properties. Current studies have shown the neuroprotective effects of polyphenols independently of their well-known antioxidant action. In this work, we have focused on reviewing the protective effect of polyphenols from extra virgin olive oil and wine in Alzheimer´s disease (AD), to emphasize that both food could be a possible therapeutic tool. Beneficial effects have been described in β-aggregation, neurofibrillary tangles, autophagy and mitochondrial function, as well as in cerebral insulin resistance. Furthermore, to date a harmful dose has not been described. Both preclinical and clinical works demonstrate that polyphenols act on neuropathological and cognitive disorders of AD, preventing or stopping the onset of this devastating disease. However, there are certain limitations in these studies, since it is very difficult to research diseases that lead to cognitive impairment. Although all the findings obtained are very encouraging, more studies should be carried out to use the polyphenols from olive oil and wine as therapeutic agents in the progression of AD. Therefore, more longitudinal studies in humans with a homogeneous cohort of patients are necessary to corroborate the efficacy of these nutraceuticals, as well as analyze which is the most appropriate dose for this purpose.

The Neuroprotective Effects of Cannabis-Derived Phytocannabinoids and Resveratrol in Parkinson's Disease: A Systematic Literature Review of Pre-Clinical Studies

Currently, there are no pharmacological treatments able to reverse nigral degeneration in Parkinson’s disease (PD), hence the unmet need for the provision of neuroprotective agents. Cannabis-derived phytocannabinoids (CDCs) and resveratrol (RSV) may be useful neuroprotective agents for PD due to their anti-oxidative and anti-inflammatory properties. To evaluate this, we undertook a systematic review of the scientific literature to assess the neuroprotective effects of CDCs and RSV treatments in pre-clinical in vivo animal models of PD. The literature databases MEDLINE, EMBASE, PsychINFO, PubMed, and Web of Science core collection were systematically searched to cover relevant studies. A total of 1034 publications were analyzed, of which 18 met the eligibility criteria for this review. Collectively, the majority of PD rodent studies demonstrated that treatment with CDCs or RSV produced a significant improvement in motor function and mitigated the loss of dopaminergic neurons. Biochemical analysis of rodent brain tissue suggested that neuroprotection was mediated by anti-oxidative, anti-inflammatory, and anti-apoptotic mechanisms. This review highlights the neuroprotective potential of CDCs and RSV for in vivo models of PD and therefore suggests their potential translation to human clinical trials to either ameliorate PD progression and/or be implemented as a prophylactic means to reduce the risk of development of PD.

Targeting Mitochondria by Plant Secondary Metabolites: A Promising Strategy in Combating Parkinson's Disease

Parkinson’s disease (PD) is one of the most prevalent and debilitating neurodegenerative conditions, and is currently on the rise. Several dysregulated pathways are behind the pathogenesis of PD; however, the critical targets remain unclear. Accordingly, there is an urgent need to reveal the key dysregulated pathways in PD. Prevailing reports have highlighted the importance of mitochondrial and cross-talked mediators in neurological disorders, genetic changes, and related complications of PD. Multiple pathophysiological mechanisms of PD, as well as the low efficacy and side effects of conventional neuroprotective therapies, drive the need for finding novel alternative agents. Recently, much attention has been paid to using plant secondary metabolites (e.g., flavonoids/phenolic compounds, alkaloids, and terpenoids) in the modulation of PD-associated manifestations by targeting mitochondria. In this line, plant secondary metabolites have shown promising potential for the simultaneous modulation of mitochondrial apoptosis and reactive oxygen species. This review aimed to address mitochondria and multiple dysregulated pathways in PD by plant-derived secondary metabolites.

Polyphenols and Stem Cells for Neuroregeneration in Parkinson's Disease and Amyotrophic Lateral Sclerosis

Parkinson's disease (PD) and Amyotrophic lateral sclerosis (ALS) are neurological disorders, pathologically characterized by chronic degeneration of dopaminergic neurons and motor neurons respectively. There is still no cure or effective treatment against the disease progression and most of the treatments are symptomatic. The present review offers an overview of the different factors involved in the pathogenesis of these diseases. Subsequently, we focused on the recent advanced studies of dietary polyphenols and stem cell therapies, which have made it possible to slow down the progression of neurodegeneration. To date, stem cells and different polyphenols have been used for the directional induction of neural stem cells into dopaminergic neurons and motor neurons. We have also discussed their involvement in the modulation of different signal transduction pathways and growth factor levels in various in vivo and in vitro studies. Likewise stem cells, polyphenols also exhibit the potential of neuroprotection by their anti-apoptotic, anti-inflammatory, anti-oxidant properties regulating the growth factors levels and molecular signaling events. Overall this review provides a detailed insight into recent strategies that promise the use of polyphenol with stem cell therapy for the possible treatment of PD and ALS.

Phenolic Analysis and In Vitro Biological Activity of Red Wine, Pomace and Grape Seeds Oil Derived from Vitis vinifera L. cv. Montepulciano d'Abruzzo

Grape pomace is commonly considered a waste product of monovarietal red wine production. Methods: HPLC-DAD analysis was performed to determine the polyphenol and flavonoid contents of all the extracts obtained from Montepulciano d’Abruzzo red wine and grape skins whereas, GC-MS was applied to the determination of fatty acid composition in grape seeds oil. Biological characterization involves antioxidant and antimicrobial assays for all the extracts and seeds oil; Their ability to inhibit α-glucosidase, α-amylase, α-tyrosinase, and ChE enzymes was also detected, together with anti-inflammatory activity on wine, grape skin extracts, and seeds oil by lipoxygenase (5-LOX) and LPS-stimulated macrophage release assays. Data indicate significative polyphenols content (199.31 ± 7.21 mgGAE/g), antioxidant (CUPRAC assay (1036.98 mgTE/g)), enzymatic inhibition (α-tyrosinase: 151.30 ± 1.20 mgKAE/g) and anti-inflammatory activities for wine-organic extract 2, while the antimicrobial activity of grape skin decoction is higher than those reported by wine extracts on three bacterial strains. Interestingly only dealcoholized wine and wine-aqueous extract exerts inhibitory effects on α-glucosidase (20.62 ± 0.23 mmolACAE/g and 19.81 ± 0.03 mmolACAE/g, respectively), while seeds oil is rich in oleic and linoleic acids. These results confirm the strong antioxidant properties of Montepulciano d’Abruzzo grape pomace, suggesting the potential use of this waste product as functional food supplements in the human diet and in cosmeceutics.

Anti-Oxidative, Anti-Inflammatory and Anti-Apoptotic Effects of Flavonols: Targeting Nrf2, NF-κB and p53 Pathways in Neurodegeneration

Neurodegenerative diseases are one of the leading causes of disability and death worldwide. Intracellular transduction pathways that end in the activation of specific transcription factors are highly implicated in the onset and progression of pathological changes related to neurodegeneration, of which those related to oxidative stress (OS) and neuroinflammation are particularly important. Here, we provide a brief overview of the key concepts related to OS- and neuroinflammation-mediated neuropathological changes in neurodegeneration, together with the role of transcription factors nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB). This review is focused on the transcription factor p53 that coordinates the cellular response to diverse genotoxic stimuli, determining neuronal death or survival. As current pharmacological options in the treatment of neurodegenerative disease are only symptomatic, many research efforts are aimed at uncovering efficient disease-modifying agents. Natural polyphenolic compounds demonstrate powerful anti-oxidative, anti-inflammatory and anti-apoptotic effects, partially acting as modulators of signaling pathways. Herein, we review the current understanding of the therapeutic potential and limitations of flavonols in neuroprotection, with emphasis on their anti-oxidative, anti-inflammatory and anti-apoptotic effects along the Nrf2, NF-κB and p53 pathways. A better understanding of cellular and molecular mechanisms of their action may pave the way toward new treatments.

Potential of Sorghum Polyphenols to Prevent and Treat Alzheimer's Disease: A Review Article

Alzheimer's disease (AD) is characterized by the excessive deposition of extracellular amyloid-beta peptide (Aβ) and the build-up of intracellular neurofibrillary tangles containing hyperphosphorylated tau proteins. This leads to neuronal damage, cell death and consequently results in memory and learning impairments leading to dementia. Although the exact cause of AD is not yet clear, numerous studies indicate that oxidative stress, inflammation, and mitochondrial dysfunction significantly contribute to its onset and progression. There is no effective therapeutic approach to stop the progression of AD and its associated symptoms. Thus, early intervention, preferably, pre-clinically when the brain is not significantly affected, is a better option for effective treatment. Natural polyphenols (PP) target multiple AD-related pathways such as protecting the brain from Aβ and tau neurotoxicity, ameliorating oxidative damage and mitochondrial dysfunction. Among natural products, the cereal crop sorghum has some unique features. It is one of the major global grain crops but in the developed world, it is primarily used as feed for farm animals. A broad range of PP, including phenolic acids, flavonoids, and condensed tannins are present in sorghum grain including some classes such as proanthocyanidins that are rarely found in others plants. Pigmented varieties of sorghum have the highest polyphenolic content and antioxidant activity which potentially makes their consumption beneficial for human health through different pathways such as oxidative stress reduction and thus the prevention and treatment of neurodegenerative diseases. This review summarizes the potential of sorghum PP to beneficially affect the neuropathology of AD.

Polyphenols and neuroprotection: Therapeutic implications for cognitive decline

Dietary polyphenols have been the focus of major interest for their potential benefits on human health. Several preclinical studies have been conducted to provide a rationale for their potential use as therapeutic agents in preventing or ameliorating cognitive decline. However, results from human studies are scarce and poorly documented. The aim of this review was to discuss the potential mechanisms involved in age-related cognitive decline or early stage cognitive impairment and current evidence from clinical human studies conducted on polyphenols and the aforementioned outcomes. The evidence published so far is encouraging but contrasting findings are to be taken into account. Most studies on anthocyanins showed a consistent positive effect on various cognitive aspects related to aging or early stages of cognitive impairment. Studies on cocoa flavanols, resveratrol, and isoflavones provided substantial contrasting results and further research is needed to clarify the therapeutic potential of these compounds. Results from other studies on quercetin, green tea flavanols, hydroxycinnamic acids (such as chlorogenic acid), curcumin, and olive oil tyrosol and derivatives are rather promising but still too few to provide any real conclusions. Future translational studies are needed to address issues related to dosage, optimal formulations to improve bioavailability, as well as better control for the overall diet, and correct target population.

Targeting autophagy using small-molecule compounds to improve potential therapy of Parkinson's disease

Parkinson's disease (PD), known as one of the most universal neurodegenerative diseases, is a serious threat to the health of the elderly. The current treatment has been demonstrated to relieve symptoms, and the discovery of new small-molecule compounds has been regarded as a promising strategy. Of note, the homeostasis of the autolysosome pathway (ALP) is closely associated with PD, and impaired autophagy may cause the death of neurons and thereby accelerating the progress of PD. Thus, pharmacological targeting autophagy with small-molecule compounds has been drawn a rising attention so far. In this review, we focus on summarizing several autophagy-associated targets, such as AMPK, mTORC1, ULK1, IMPase, LRRK2, beclin-1, TFEB, GCase, ERRα, C-Abelson, and as well as their relevant small-molecule compounds in PD models, which will shed light on a clue on exploiting more potential targeted small-molecule drugs tracking PD treatment in the near future.

Vitis Vinifera Leaf Extract Protects Against Glutamate-Induced Oxidative Toxicity in HT22 Hippocampal Neuronal Cells and Increases Stress Resistance Properties in Caenorhabditis Elegans

Vitis vinifea has been used for traditional medicines, food, beverages, and dietary antioxidant supplements. The chemical compositions and biological activities of the fruits and seeds have been extensively investigated. However, the biological effects of the leaves are limited, and its anti-neurodegeneration or antiaging activities are little known. The current work aims to study the beneficial effects of V. vinifera leaf extract on neuroprotective effects in HT22 cells, antiaging, and oxidative stress resistance properties in the Caenorhabditis elegans model. The ethanol extract was characterized by phytochemical composition using gas/liquid chromatography–mass spectrometry and reversed-phase high-performance liquid chromatography. The beneficial effects of V. vinifera ethanol (VVE) extract on antioxidant properties, neuroprotective effects, and the underlying mechanisms were studied by in vitro and in vivo studies. In HT22 cells, we found that VVE has a protective effect against glutamate-mediated oxidative stress-induced cell death. The gene expression of cellular antioxidant enzymes such as CAT, SODs, GSTs, and GPx was upregulated by VVE treatment. Moreover, VVE was also shown to alleviate oxidative stress and attenuate reactive oxygen species accumulation in C. elegans. We demonstrated that VVE could upregulate the expression of stress-response genes gst-4 and sod-3 and downregulate the expression of hsp-16.2. Our results suggest that the oxidative stress resistance properties of VVE are possibly involved in DAF-16/FoxO transcription factors. VVE reduced age-related markers (lipofuscin) while did not extend the life span of C. elegans under normal conditions. This study reports the neuroprotective effect and antioxidant activity of V. vinifera leaf extract and suggests its potential as a dietary or alternative supplement to defend against oxidative stress and age-related diseases.

The Role of PGC1α in Alzheimer's Disease and Therapeutic Interventions

The peroxisome proliferator-activated receptor co-activator-1α (PGC1α) belongs to a family of transcriptional regulators, which act as co-activators for a number of transcription factors, including PPARs, NRFs, oestrogen receptors, etc. PGC1α has been implicated in the control of mitochondrial biogenesis, the regulation of the synthesis of ROS and inflammatory cytokines, as well as genes controlling metabolic processes. The levels of PGC1α have been shown to be altered in neurodegenerative disorders. In the brains of Alzheimer's disease (AD) patients and animal models of amyloidosis, PGC1α expression was reduced compared with healthy individuals. Recently, it was shown that overexpression of PGC1α resulted in reduced amyloid-β (Aβ) generation, particularly by regulating the expression of BACE1, the rate-limiting enzyme involved in the production of Aβ. These results provide evidence pointing toward PGC1α activation as a new therapeutic avenue for AD, which has been supported by the promising observations of treatments with drugs that enhance the expression of PGC1α and gene therapy studies in animal models of AD. This review summarizes the different ways and mechanisms whereby PGC1α can be neuroprotective in AD and the pre-clinical treatments that have been explored so far.

Mechanistic insights and perspectives involved in neuroprotective action of quercetin

Neurodegenerative diseases (NDDs) are the primary cause of disabilities in the elderly people. Growing evidence indicates that oxidative stress, mitochondrial dysfunction, neuroinflammation and apoptosis are associated with aging and the basis of most neurodegenerative disorders. Quercetin is a flavonoid with significant pharmacological effects and promising therapeutic potential. It is widely distributed among plants and typically found in daily diets mainly in fruits and vegetables. It shows a number of biological properties connected to its antioxidant activity. Neuroprotection by quercetin has been reported in many in vitro as well as in in vivo studies. However, the exact mechanism of action is still mystery and similarly there are a number of hypothesis exploring the mechanism of neuroprotection. Quercetin enhances neuronal longevity and neurogenesis by modulating and inhibiting wide number of pathways. This review assesses the food sources of quercetin, its pharmacokinetic profile, structure activity relationship and its pathophysiological role in various NDDs and it also provides a synopsis of the literature exploring the relationship between quercetin and various downstream signalling pathways modulated by quercetin for neuroprotection for eg. nuclear factor erythroid 2-related factor 2 (Nrf2), Paraoxonase-2 (PON2), c-Jun N-terminal kinase (JNK), Tumour Necrosis Factor alpha (TNF-α), Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha (PGC-1α), Sirtuins, Mitogen-activated protein kinases (MAPKs) signalling cascades, CREB (Cyclic AMP response element binding protein) and Phosphoinositide 3- kinase(PI3K/Akt). Therefore, the aim of the present review was to elaborate on the cellular and molecular mechanisms of the quercetin involved in the protection against NDDs.

A Grape Juice Supplemented with Natural Grape Extracts Is Well Accepted by Consumers and Reduces Brain Oxidative Stress

Neurodegenerative diseases pose a major health problem for developed countries. Stress, which induces oxidation in the brain, has been identified as the main risk factor for these disorders. We have developed an antioxidant-enriched drink and have examined its protective properties against acute oxidative stress. We found that addition of red grape polyphenols and MecobalActive^® to grape juice did not provoke changes in juice organoleptic characteristics, and that the pasteurization process did not greatly affect the levels of flavonoids and vitamin B12. Out of all combinations, grape juice with red grape polyphenols was selected by expert judges (28.6% selected it as their first choice). In vivo, oral administration of grape juice supplemented with red grape polyphenols exerted an antioxidant effect in the brain of stressed mice reducing two-fold the expression of genes involved in inflammation and oxidation mechanisms and increasing three-fold the expression of genes related to protection against oxidative stress. In addition, we found that this drink augmented antioxidant enzyme activity (17.8 vs. 8.2 nmol/mg), and prevented lipid peroxidation in the brain (49.7 vs. 96.5 nmol/mg). Therefore, we propose supporting the use of this drink by the general population as a new and global strategy for the prevention of neurodegeneration.

Can Natural Products Exert Neuroprotection without Crossing the Blood-Brain Barrier?

The scope of evidence on the neuroprotective impact of natural products has been greatly extended in recent years. However, a key question that remains to be answered is whether natural products act directly on targets located in the central nervous system (CNS), or whether they act indirectly through other mechanisms in the periphery. While molecules utilized for brain diseases are typically bestowed with a capacity to cross the blood–brain barrier, it has been recently uncovered that peripheral metabolism impacts brain functions, including cognition. The gut–microbiota–brain axis is receiving increasing attention as another indirect pathway for orally administered compounds to act on the CNS. In this review, we will briefly explore these possibilities focusing on two classes of natural products: omega-3 polyunsaturated fatty acids (n-3 PUFAs) from marine sources and polyphenols from plants. The former will be used as an example of a natural product with relatively high brain bioavailability but with tightly regulated transport and metabolism, and the latter as an example of natural compounds with low brain bioavailability, yet with a growing amount of preclinical and clinical evidence of efficacy. In conclusion, it is proposed that bioavailability data should be sought early in the development of natural products to help identifying relevant mechanisms and potential impact on prevalent CNS disorders, such as Alzheimer’s disease.

Polyphenol-Peptide Interactions in Mitigation of Alzheimer's Disease: Role of Biosurface-Induced Aggregation

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder, responsible for nearly two-thirds of all dementia cases. In this review, we report the potential AD treatment strategies focusing on natural polyphenol molecules (green chemistry) and more specifically on the inhibition of polyphenol-induced amyloid aggregation/disaggregation pathways: in bulk and on biosurfaces. We discuss how these pathways can potentially alter the structure at the early stages of AD, hence delaying the aggregation of amyloid-β (Aβ) and tau. We also discuss multidisciplinary approaches, combining experimental and modelling methods, that can better characterize the biochemical and biophysical interactions between proteins and phenolic ligands. In addition to the surface-induced aggregation, which can occur on surfaces where protein can interact with other proteins and polyphenols, we suggest a new concept referred as "confinement stability". Here, on the contrary, the adsorption of Aβ and tau on biosurfaces other than Aβ- and tau-fibrils, e.g., red blood cells, can lead to confinement stability that minimizes the aggregation of Aβ and tau. Overall, these mechanisms may participate directly or indirectly in mitigating neurodegenerative diseases, by preventing protein self-association, slowing down the aggregation processes, and delaying the progression of AD.

Role of medicinal plants against neurodegenerative diseases

Diseases with a significant loss of neurons, structurally and functionally are termed as neurodegenerative diseases. Due to the present therapeutic interventions and progressive nature of diseases, a variety of side effects have risen up, thus leading the patients to go for an alternative medication. The role of medicinal plants in such cases has been beneficial because of their exhibition via different cellular and molecular mechanisms. Alleviation in inflammatory responses, suppression of the functionary aspect of pro-inflammatory cytokines like a tumor, improvement in antioxidative properties is among few neuroprotective mechanisms of traditional plants. Variation in transcription and transduction pathways play a vital role in the preventive measures of plants in such diseases. Neurodegenerative diseases are generally caused by depletion of proteins, oxidative and inflammatory stress, environmental changes and so on, with aging being the most important cause. Natural compounds can be used in order to treat neurodegenerative diseases Medicinal plants such as Ginseng, Withania somnifera, Bacopa monnieri, Ginkgo biloba, etc. are some of the medicinal plants for prevention of neurological symptoms. This review deals with the use of different medicinal plants for the prevention of neurodegenerative diseases.

Date seeds alleviate behavioural and neuronal complications of metabolic syndrome in rats

Unhealthy dietary habits can play a crucial role in metabolic damages, promoting alteration of neural functions through the lifespan. Recently, dietary change has been perceived as the first line intervention in prevention and/or treatment of metabolic damages and related diseases. In this context, our study was designed to assess the eventual therapeutic effect of date seeds administration on memory and learning and on neuronal markers in a rat Metabolic Syndrome model. For this purpose, 32 adult male Wistar rats were fed with standard diet or high-fat high-sugar diet during ten weeks. After this, 16 rats were sacrified and the remaining rats received an oral administration of 300 mg of date seeds/kg of body weight during four supplementary weeks. Before sacrifice, we evaluate cognitive performances by the Barnes maze test. Afterwards, neuronal, astrocytic, microtubular and oxidative markers were investigated by immunoblotting methods. In Metabolic syndrome rats, results showed impairment of spatial memory and histological alterations. We identified neuronal damages in hippocampus, marked by a decrease of NeuN and an increase of GFAP and pTau396. Finally, we recorded an increase in protein oxidation and lipid peroxidation, respectively identified by an up-regulation of protein carbonyls and 4-HNe. Interestingly, date seeds administration improved these behavioural, histological, neuronal and oxidative damages highlighting the neuroprotective effect of this natural compound. Liquid Chromatography-Mass Spectrometry (LC-MS) identified, in date seeds, protocatechuic acid, caffeoylshikimic acid and vanillic acid, that could potentially prevent the progression of neurodegenerative diseases, acting through their antioxidant properties.

Neuroinflammation Mechanisms and Phytotherapeutic Intervention: A Systematic Review

Neuroinflammation is indicated in the pathogenesis of several acute and chronic neurological disorders. Acute lesions in the brain parenchyma induce intense and highly complex neuroinflammatory reactions with similar mechanisms among various disease prototypes. Microglial cells in the CNS sense tissue damage and initiate inflammatory responses. The cellular and humoral constituents of the neuroinflammatory reaction to brain injury contribute significantly to secondary brain damage and neurodegeneration. Inflammatory cascades such as proinflammatory cytokines from invading leukocytes and direct cell-mediated cytotoxicity between lymphocytes and neurons are known to cause "collateral damage" in models of acute brain injury. In addition to degeneration and neuronal cell loss, there are secondary inflammatory mechanisms that modulate neuronal activity and affect neuroinflammation which can even be detected at the behavioral level. Hence, several of health conditions result from these pathogenetic conditions which are underlined by progressive neuronal function loss due to chronic inflammation and oxidative stress. In the first part of this Review, we discuss critical neuroinflammatory mediators and their pathways in detail. In the second part, we review the phytochemicals which are considered as potential therapeutic molecules for treating neurodegenerative diseases with an inflammatory component.

Prevention by Dietary Polyphenols (Resveratrol, Quercetin, Apigenin) Against 7-Ketocholesterol-Induced Oxiapoptophagy in Neuronal N2a Cells: Potential Interest for the Treatment of Neurodegenerative and Age-Related Diseases

The Mediterranean diet is associated with health benefits due to bioactive compounds such as polyphenols. The biological activities of three polyphenols (quercetin (QCT), resveratrol (RSV), apigenin (API)) were evaluated in mouse neuronal N2a cells in the presence of 7-ketocholesterol (7KC), a major cholesterol oxidation product increased in patients with age-related diseases, including neurodegenerative disorders. In N2a cells, 7KC (50 µM; 48 h) induces cytotoxic effects characterized by an induction of cell death. When associated with RSV, QCT and API (3.125; 6.25 µM), 7KC-induced toxicity was reduced. The ability of QCT, RSV and API to prevent 7KC-induced oxidative stress was characterized by a decrease in reactive oxygen species (ROS) production in whole cells and at the mitochondrial level; by an attenuation of the increase in the level and activity of catalase; by attenuating the decrease in the expression, level and activity of glutathione peroxidase 1 (GPx1); by normalizing the expression, level and activity of superoxide dismutases 1 and 2 (SOD1, SOD2); and by reducing the decrease in the expression of nuclear erythroid 2-like factor 2 (Nrf2) which regulates antioxidant genes. QCT, RSV and API also prevented mitochondrial dysfunction in 7KC-treated cells by counteracting the loss of mitochondrial membrane potential (ΨΔm) and attenuating the decreased gene expression and/or protein level of AMP-activated protein kinase α (AMPKα), sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) implicated in mitochondrial biogenesis. At the peroxisomal level, QCT, RSV and API prevented the impact of 7KC by counteracting the decrease in ATP binding cassette subfamily D member (ABCD)3 (a peroxisomal mass marker) at the protein and mRNA levels, as well as the decreased expresssion of genes associated with peroxisomal biogenesis (Pex13, Pex14) and peroxisomal β-oxidation (Abcd1, Acox1, Mfp2, Thiolase A). The 7KC-induced decrease in ABCD1 and multifunctional enzyme type 2 (MFP2), two proteins involved in peroxisomal β-oxidation, was also attenuated by RSV, QCT and API. 7KC-induced cell death, which has characteristics of apoptosis (cells with fragmented and/or condensed nuclei; cleaved caspase-3; Poly(ADP-ribose) polymerase (PARP) fragmentation) and autophagy (cells with monodansyl cadaverine positive vacuoles; activation of microtubule associated protein 1 light chain 3–I (LC3-I) to LC3-II, was also strongly attenuated by RSV, QCT and API. Thus, in N2a cells, 7KC induces a mode of cell death by oxiapoptophagy, including criteria of OXIdative stress, APOPTOsis and autoPHAGY, associated with mitochondrial and peroxisomal dysfunction, which is counteracted by RSV, QCT, and API reinforcing the interest for these polyphenols in prevention of diseases associated with increased 7KC levels.

Functional Foods: An Approach to Modulate Molecular Mechanisms of Alzheimer's Disease

A new epoch is emerging with intense research on nutraceuticals, i.e., "food or food product that provides medical or health benefits including the prevention and treatment of diseases", such as Alzheimer's disease. Nutraceuticals act at different biochemical and metabolic levels and much evidence shows their neuroprotective effects; in particular, they are able to provide protection against mitochondrial damage, oxidative stress, toxicity of β-amyloid and Tau and cell death. They have been shown to influence the composition of the intestinal microbiota significantly contributing to the discovery that differential microorganisms composition is associated with the formation and aggregation of cerebral toxic proteins. Further, the routes of interaction between epigenetic mechanisms and the microbiota-gut-brain axis have been elucidated, thus establishing a modulatory role of diet-induced epigenetic changes of gut microbiota in shaping the brain. This review examines recent scientific literature addressing the beneficial effects of some natural products for which mechanistic evidence to prevent or slowdown AD are available. Even if the road is still long, the results are already exceptional.

Natural and Synthetic Derivatives of Hydroxycinnamic Acid Modulating the Pathological Transformation of Amyloidogenic Proteins

This review presents the main properties of hydroxycinnamic acid (HCA) derivatives and their potential application as agents for the prevention and treatment of neurodegenerative diseases. It is partially focused on the successful use of these compounds as inhibitors of amyloidogenic transformation of proteins. Firstly, the prerequisites for the emergence of interest in HCA derivatives, including natural compounds, are described. A separate section is devoted to synthesis and properties of HCA derivatives. Then, the results of molecular modeling of HCA derivatives with prion protein as well as with α-synuclein fibrils are summarized, followed by detailed analysis of the experiments on the effect of natural and synthetic HCA derivatives, as well as structurally similar phenylacetic and benzoic acid derivatives, on the pathological transformation of prion protein and α-synuclein. The ability of HCA derivatives to prevent amyloid transformation of some amyloidogenic proteins, and their presence not only in food products but also as natural metabolites in human blood and tissues, makes them promising for the prevention and treatment of neurodegenerative diseases of amyloid nature.