Resveratrol Brain Delivery for Neurological Disorders Prevention and Treatment

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.

Quantifying morphologies of developing neuronal cells using deep learning with imperfect annotations

The functionality of human intelligence relies on the interaction and health of neurons, hence, quantifying neuronal morphologies can be crucial for investigating the functionality of the human brain. This paper proposes a deep learning (DL) based method for segmenting and quantifying neuronal structures in fluorescence microscopy images of developing neuronal cells cultured in vitro. Compared to the majority of supervised DL-based segmentation methods that heavily rely on creating exact corresponding masks of neuronal structures for the preparation of training samples, the proposed approach allows for imperfect annotation of neurons, as it only requires tracing the centrelines of the neurites. This ability accelerates the preparation of training data by several folds. Our proposed framework is built on a modified version of PSPNet with an EfficientNet backbone pre-trained on the CityScapes dataset. To handle the imperfectness of training samples, we incorporated a weighted combination of two loss functions, namely the Dice loss and Lovász loss functions, into our network. We evaluated the proposed framework and several other state-of-the-art methods on a published dataset of approximately 900 manually quantified cultured mouse neurons. Our results indicate a close correlation between the proposed method and manual quantification in terms of neuron length and the number of branches while demonstrating improved analysis speed. Furthermore, the proposed method achieved high accuracy in neuron segmentation, as evidenced by the evaluation of the neurons' length and number of branches.

Nature's Toolbox for Alzheimer's Disease: A Review on the Potential of Natural Products as Alzheimer's Disease Drugs

Numerous clinical trials involving natural products have been conducted to observe cognitive performances and biomarkers in Alzheimer's Disease (AD) patients. However, to date, no natural-based drugs have been approved by the FDA as treatments for AD. In this review, natural product-based compounds that were tested in clinical trials from 2011 to 2023, registered at www.clinicaltrials.gov were reviewed. Thirteen compounds, encompassing 7 different mechanisms of action were covered. Several observations were deduced, which are: i) several compounds showed cognitive improvement, but these improvements may not extend to AD, ii) compounds that are endogenous to the human body showed better outcomes, and iii) Docosahexaenoic acid (DHA) and cerebrolysin had the most potential as AD drugs among the 13 compounds. Based on the current findings, natural products may be more suitable as a supplement than AD drugs in most cases. However, the studies covered here were conducted in a relatively short amount of time, where compounds acting on AD pathways may take time to show any effect. Given the diverse pathways that these natural products are involved in, they may potentially produce synergistic effects that would be beneficial in treating AD. Additionally, natural products benefit from both physicochemical properties being in more favorable ranges and active transport playing a more significant role than it does for synthetic compounds.

Cytotoxic Activity of the Red Grape Polyphenol Resveratrol against Human Prostate Cancer Cells: A Molecular Mechanism Mediated by Mobilization of Nuclear Copper and Generation of Reactive Oxygen Species

Resveratrol, a polyphenolic compound found primarily in red grapes and pomegranates is known as an antioxidant but can act as a pro-oxidant when copper ions are present. Here, resveratrol is demonstrated to reduce cell growth (as evaluated by MTT assay) and promote apoptosis-like cell death (as measured by Histone/DNA ELISA) in prostate cancer cell lines PC3 and C42B. This effect is effectively inhibited by a copper chelator (neocuproine) and reactive oxygen species (ROS) scavengers (thiourea for hydroxyl radical, superoxide dismutase for superoxide anion, and catalase for hydrogen peroxide). These inhibitory effects provide evidence that intracellular copper reacts with resveratrol within cancer cells, resulting in DNA damage via the generation of reactive oxygen species. Additionally, it has been demonstrated that non-tumorigenic epithelial cell lines (MCF-10A) grown in media supplemented with copper are more susceptible to growth inhibition by resveratrol, as confirmed by the observed reduction in cell proliferation. Copper supplementation induces enhanced expression of the copper transporter CTR1 in MCF-10A cells, which is reduced by the addition of resveratrol to the media. The selective cell death of cancer cells generated by copper-mediated and ROS mechanisms may help to explain the anticancer properties of resveratrol.

Enhancing the Bioavailability of Resveratrol: Combine It, Derivatize It, or Encapsulate It?

Overcoming the limited bioavailability and extensive metabolism of effective in vitro drugs remains a challenge that limits the translation of promising drugs into clinical trials. Resveratrol, despite its well-reported therapeutic benefits, is not metabolically stable and thus has not been utilized as an effective clinical drug. This is because it needs to be consumed in large amounts to overcome the burdens of bioavailability and conversion into less effective metabolites. Herein, we summarize the more relevant approaches to modify resveratrol, aiming to increase its biological and therapeutic efficacy. We discuss combination therapies, derivatization, and the use of resveratrol nanoparticles. Interestingly, the combination of resveratrol with established chemotherapeutic drugs has shown promising therapeutic effects on colon cancer (with oxaliplatin), liver cancer (with cisplatin, 5-FU), and gastric cancer (with doxorubicin). On the other hand, derivatizing resveratrol, including hydroxylation, amination, amidation, imidation, methoxylation, prenylation, halogenation, glycosylation, and oligomerization, differentially modifies its bioavailability and could be used for preferential therapeutic outcomes. Moreover, the encapsulation of resveratrol allows its trapping within different forms of shells for targeted therapy. Depending on the nanoparticle used, it can enhance its solubility and absorption, increasing its bioavailability and efficacy. These include polymers, metals, solid lipids, and other nanoparticles that have shown promising preclinical results, adding more "hype" to the research on resveratrol. This review provides a platform to compare the different approaches to allow directed research into better treatment options with resveratrol.

Plasma Gel Matrix as a Promising Carrier of Epigallocatechin Gallate for Regenerative Medicine

Plasma gel (PG) is a protein matrix prepared from platelet-poor plasma and can be utilized as a drug carrier for controlled release. We previously demonstrated its applicability as a carrier of polyphosphate. Epigallocatechin-3-gallate (EGCG) is the main flavonoid found in green tea and functions as a strong antioxidant. To explore the applicability of PG as an EGCG carrier, we examined the release of EGCG from the PG matrix using an in vitro system. Pooled platelet-poor plasma (PPP) was prepared from four healthy adult male donors, mixed with EGCG, and heated at 75 °C for 10 or 20 min to prepare the PG matrix. The PG-EGCG matrix was incubated in PBS at 37 °C, and the EGCG released into PBS was determined using spectrophotometry. The antioxidant capacity was determined based on the principle of the iodine decolorization reaction. EGCG precipitated and incorporated into the PG matrix during thermal preparation. Trypsin, used to simulate the in vivo degradation of PG, released EGCG from the PG matrix over time. The released EGCG maintained its antioxidant capacity during incubation. These results indicate that thermally prepared PG matrices can be utilized as a promising EGCG carrier in the fields of tissue engineering and regenerative medicine.

Role of autophagy and proteostasis in neurodegenerative diseases: Exploring the therapeutic interventions

Neurodegenerative disorders are devastating disorders characterized by gradual loss of neurons and cognition or mobility impairment. The common pathological features of these diseases are associated with the accumulation of misfolded or aggregation of proteins. The pivotal roles of autophagy and proteostasis in maintaining cellular health and preventing the accumulation of misfolded proteins, which are associated with neurodegenerative diseases like Huntington's disease (HD), Alzheimer's disease (AD), and Parkinson's disease (PD). This article presents an in-depth examination of the interplay between autophagy and proteostasis, highlighting how these processes cooperatively contribute to cellular homeostasis and prevent pathogenic protein aggregate accumulation. Furthermore, the review emphasises the potential therapeutic implications of targeting autophagy and proteostasis to mitigate neurodegenerative diseases. While advancements in research hold promise for developing novel treatments, the article also addresses the challenges and complexities associated with modulating these intricate cellular pathways. Ultimately, advancing understanding of the underlying mechanism of autophagy and proteostasis in neurodegenerative disorders provides valuable insights into potential therapeutic avenues and future research directions.

A soy protein enzymatic digest mitigates Nrf2-related oxidative stress and attenuates depression-like behavior in a mouse model of sub-chronic restraint stress

Continuous oxidative stress conditions have been identified as a major cause of various neuropsychiatric disorders, including depression. The present study investigated the potential antidepressant-like effects of a soy protein enzymatic digest (SPD) containing soy-deprestatin, which is a soy-derived peptide with reported antidepressant-like effects, as well as its ability to mitigate oxidative stress in the brain caused by sub-chronic restraint stress. Mice were divided into two groups: a control group and restraint stress group. The restraint stress group was further divided into two groups administered water or SPD. After repeated short-time restraints over five days, we evaluated immobility times in the tail suspension test, and antioxidant enzyme activities, glutathione levels, oxidative stress maker levels, and the gene expression levels of Nrf2 and antioxidant enzymes in the brain. The results obtained showed that the oral administration of SPD reduced immobility times in mice exposed to restraint stress. In comparisons with the water-treated restraint group, the administration of SPD restored superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities and glutathione levels and prevented restraint stress-induced increases in malondialdehyde, carbonyl protein, and 8-OHdG levels in the restraint stress group. In addition, high expression levels of Nrf2, HO-1, NQO-1 and GCLC were observed in the SPD-treated restraint group. These results suggest that SPD attenuated repeated restraint stress-induced depression-like behaviors by mitigating oxidative stress through the activation of the Nrf2 signaling pathway.

Therapeutic potential of stilbenes in neuropsychiatric and neurological disorders: A comprehensive review of preclinical and clinical evidence

Neuropsychiatric disorders are anticipated to be a leading health concern in the near future, emphasizing an outstanding need for the development of new effective therapeutics to treat them. Stilbenes, with resveratrol attracting the most attention, are an example of multi-target compounds with promising therapeutic potential for a broad array of neuropsychiatric and neurological conditions. This review is a comprehensive summary of the current state of research on stilbenes in several neuropsychiatric and neurological disorders such as depression, anxiety, schizophrenia, autism spectrum disorders, epilepsy, traumatic brain injury, and neurodegenerative disorders. We describe and discuss the results of both in vitro and in vivo studies. The majority of studies concentrate on resveratrol, with limited findings exploring other stilbenes such as pterostilbene, piceatannol, polydatin, tetrahydroxystilbene glucoside, or synthetic resveratrol derivatives. Overall, although extensive preclinical studies show the potential benefits of stilbenes in various central nervous system disorders, clinical evidence on their therapeutic efficacy is largely missing.

Recent Developments in Nanoparticle Formulations for Resveratrol Encapsulation as an Anticancer Agent

Resveratrol is a polyphenolic compound that has gained considerable attention in the past decade due to its multifaceted therapeutic potential, including anti-inflammatory and anticancer properties. However, its anticancer efficacy is impeded by low water solubility, dose-limiting toxicity, low bioavailability, and rapid hepatic metabolism. To overcome these hurdles, various nanoparticles such as organic and inorganic nanoparticles, liposomes, polymeric nanoparticles, dendrimers, solid lipid nanoparticles, gold nanoparticles, zinc oxide nanoparticles, zeolitic imidazolate frameworks, carbon nanotubes, bioactive glass nanoparticles, and mesoporous nanoparticles were employed to deliver resveratrol, enhancing its water solubility, bioavailability, and efficacy against various types of cancer. Resveratrol-loaded nanoparticle or resveratrol-conjugated nanoparticle administration exhibits excellent anticancer potency compared to free resveratrol. This review highlights the latest developments in nanoparticle-based delivery systems for resveratrol, focusing on the potential to overcome limitations associated with the compound's bioavailability and therapeutic effectiveness.

Effect of gold-conjugated resveratrol nanoparticles on glioma cells and its underlying mechanism

BACKGROUND

 Glioblastoma is the most aggressive brain tumor with poor prognosis. Although Resveratrol (Rsv) is known to have therapeutic effects on glioma, the effects of gold-conjugated resveratrol nanoparticles (Rsv-AuNPs) on glioma cells are rarely reported.

OBJECTIVE

We aimed to investigate the effects of Rsv-AuNPs on glioma cells and its underlying mechanism.

METHOD

Human glioma cell line U87 was treated with different concentrations of Rsv-AuNPs. CCK-8, transwell, and wound healing assay were performed to measure the effects of Rsv-AuNPs on cell proliferation, invasion, and migration ability, respectively. Flow cytometry assay was used to detect the effects of Rsv-AuNPs on apoptosis. Changes of protein expressions related to proliferation, invasion, migration, and apoptosis were measured by Western blot assay. In addition, the inhibitory role of Rsv-AuNPs in the PI3K/AKT/mTOR signaling pathway was verified by using PI3K inhibitor LY294002.

RESULTS

Rsv-AuNPs treatment significantly suppressed proliferation, migration, and invasion of U87 cells (all P < 0.05) and increased the apoptosis rate (P < 0.05). The changes of proteins related to proliferation, migration, invasion and apoptosis were consistent (all P < 0.05). Moreover, Rsv-AuNPs treatment significantly inhibited the phosphorylation of PI3K, AKT and mTOR proteins in U87 cells (P < 0.05).

CONCLUSION

The present study found that Rsv-AuNPs inhibited the proliferation, migration, and invasion of U87 cells and induced apoptosis by inhibiting the activation of PI3K/AKT/mTOR signaling pathway. In the future, Rsv-AuNPs might be applied to the clinical treatment of glioma through more in-depth animal and clinical research.

Nano biomaterials based strategies for enhanced brain targeting in the treatment of neurodegenerative diseases: an up-to-date perspective

Neurons and their connecting axons gradually degenerate in neurodegenerative diseases (NDs), leading to dysfunctionality of the neuronal cells and eventually their death. Drug delivery for the treatment of effected nervous system is notoriously complicated because of the presence of natural barriers, i.e., the blood-brain barrier and the blood cerebrospinal fluid barrier. Palliative care is currently the standard care for many diseases. Therefore, treatment programs that target the disease's origin rather than its symptoms are recommended. Nanotechnology-based drug delivery platforms offer an innovative way to circumvent these obstacles and deliver medications directly to the central nervous system, thereby enabling treatment of several common neurological problems, i.e., Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. Interestingly, the combination of nanomedicine and gene therapy enables targeting of selective mutant genes responsible for the progression of NDs, which may provide a much-needed boost in the struggle against these diseases. Herein, we discussed various central nervous system delivery obstacles, followed by a detailed insight into the recently developed techniques to restore neurological function via the differentiation of neural stem cells. Moreover, a comprehensive background on the role of nanomedicine in controlling neurogenesis via differentiation of neural stem cells is explained. Additionally, numerous phytoconstituents with their neuroprotective properties and molecular targets in the identification and management of NDs are also deliberated. Furthermore, a detailed insight of the ongoing clinical trials and currently marketed products for the treatment of NDs is provided in this manuscript.

Natural products for the treatment of neurodegenerative diseases

BACKGROUND

Neurodegenerative diseases are among the most common diseases in older adults worldwide. Alzheimer's disease (AD) and Parkinson's disease (PD) are two of the most common neurodegenerative diseases, and are accompanied by cerebral cortical atrophy, neuronal loss, protein accumulation, and excessive accumulation of metal ions. Natural products exhibit outstanding performance in improving cerebral circulatory disorders, promoting cerebral haematoma absorption, repairing damaged nerve tissue, and improving damaged nerve function. In recent years, studies have shown that neuroinflammatory mechanisms and signalling pathways closely related to the occurrence and development of neurological diseases include microglial activation, nuclear factor-κB (NF-κB) pathway, mitogen activated protein kinases (MAPK) pathway, reactive oxygen pathway, nucleotide binding oligomerisation domain-like receptor protein3 (NLRP3) inflammasomes, toll-like receptor4 (TLR4) pathway, nuclear factor erythroid 2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) pathway, phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway, and intestinal flora. Therefore, this study considered the mechanism of neurological diseases as the starting point to review the mechanism of action of natural products in the prevention and treatment of AD and PD in recent years to provide a theoretical basis for clinical prevention and treatment.

AIM

Natural products are a promising source of novel lead structures that have long been used to treat various nervous system diseases.

METHODOLOGY

This review collected literature on neurological diseases and natural products from 2012 to 2022, which were mainly searched through databases such as ScienceDirect, Springer, PubMed, SciFinder, China National Knowledge Infrastructure (CNKI), Wanfang, Google Scholar, and Baidu Academic. The following keywords were searched: neurological disorders, natural products, signalling pathway, mechanism of action.

RESULTS

This review summarises the pathogenesis of degenerative neurological diseases, recent findings on natural products used in neurodegenerative diseases, and the molecular mechanisms underlying these effects.

Understanding the Molecular Mechanisms of Polyphenol Inhibition of Amyloid β Aggregation

Alzheimer's disease (AD) is highly associated with self-aggregation of amyloid β (Aβ) proteins into fibrils. Inhibition of Aβ aggregation by polyphenols is one of the major therapeutic strategies for AD. Among them, four polyphenols (brazilin, resveratrol, hematoxylin, and rosmarinic acid) have been reported to be effective at inhibiting Aβ aggregation, but the inhibition mechanisms are still unclear. In this work, these four polyphenols were selected to explore their interactions with the Aβ17-42 pentamer by molecular dynamics simulation. All four polyphenols can bind to the pentamer tightly but prefer different binding sites. Conversion of the β-sheet to the random coil, fewer interchain hydrogen bonds, and weaker salt bridges were observed after binding. Interestingly, different Aβ17-42 pentamer destabilizing mechanisms for resveratrol and hematoxylin were found. Resveratrol inserts into the hydrophobic core of the pentamer by forming hydrogen bonds with Asp23 and Lys28, while hematoxylin prefers to bind beside chain A of the pentamer, which leads to β-sheet offset and dissociation of the β1 sheet of chain E. This work reveals the interactions between the Aβ17-42 pentamer and four polyphenols and discusses the relationship between inhibitor structures and their inhibition mechanisms, which also provides useful guidance for screening effective Aβ aggregation inhibitors and drug design against AD.

Resveratrol improves the prognosis of rats after spinal cord injury by inhibiting mitogen-activated protein kinases signaling pathway

Spinal cord injury (SCI) is a serious condition that results in irreparable nerve damage and severe loss of motor or sensory function. Resveratrol (3,4',5-trihy- droxystilbene) is a naturally occurring plant-based polyphenol that has demonstrated powerful antioxidative, anti-inflammatory, and anti-carcinogenic pharmaceutical properties in previous studies. In the central nervous system, it promotes neuronal recovery and protects residual function. However, the role of resveratrol in SCI recovery remains elusive. In this study, the potential mechanisms by which resveratrol affect SCI in rats were assessed by constructing a contusion model of SCI. Resveratrol was intraperitoneally administered to rats. Behavioral scores and electrophysiological examinations were performed to assess functional recovery. After magnetic resonance imaging and staining with hematoxylin and eosin (HE) and Luxor Fast Blue (LFB), tissue recovery was analyzed. Immunofluorescence with NeuN and glial fibrillary acidic protein (GFAP) was employed to evaluate neuronal survival and glial changes. TdT-mediated dUTP nick end labeling (TUNEL) assay was performed to examine apoptotic rates. Moreover, network pharmacology was performed to identify relevant pathways of resveratrol for the treatment of SCI. Lastly, ELISA was performed to detect the expression levels of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and IL-6. Our findings revealed that resveratrol dramatically improved the hindlimb locomotor function and their electrophysiological outcomes. Notably, lesion size was significantly reduced on magnetic resonance imaging. HE and LFB staining exposed increased sparseness of tissue and myelin. GFAP and NeuN immunofluorescence assays at the lesion site determined that resveratrol boosted neuronal survival and attenuated glial cell overgrowth. In addition, resveratrol reduced the density and number of TUNEL-positive cells in rats after injury. Additionally, gene ontology analysis revealed that the enriched differentially expressed protein was associated with the JNK/p38MAPK (c-jun N-terminal kinase/p38 mitogen-activated protein kinase) signaling pathway. Following resveratrol treatment, the expression levels of IL-1β, TNF-α, and IL-6 were decreased. In summary, the administration of resveratrol protects motor function and neuronal survival in rats after SCI. Furthermore, resveratrol exerts an anti-inflammatory effect by blocking the JNK/p38MAPK signaling pathway.

The Pharmacological Properties of Red Grape Polyphenol Resveratrol: Clinical Trials and Obstacles in Drug Development

Resveratrol is a stilbenoid from red grapes that possesses a strong antioxidant activity. Resveratrol has been shown to have anticancer activity, making it a promising drug for the treatment and prevention of numerous cancers. Several in vitro and in vivo investigations have validated resveratrol's anticancer capabilities, demonstrating its ability to block all steps of carcinogenesis (such as initiation, promotion, and progression). Additionally, resveratrol has been found to have auxiliary pharmacological effects such as anti-inflammatory, cardioprotective, and neuroprotective activity. Despite its pharmacological properties, several obstacles, such as resveratrol's poor solubility and bioavailability, as well as its adverse effects, continue to be key obstacles to drug development. This review critically evaluates the clinical trials to date and aims to develop a framework to develop resveratrol into a clinically viable drug.

The Role of Glucose Concentration and Resveratrol in Modulating Neuroinflammatory Cytokines: Insights from an In Vitro Blood-Brain Barrier Model

BACKGROUND The prevalence of type 2 diabetes mellitus is rising, presumably because of a coexisting pandemic of obesity. Since diabetic neuropathy and neuroinflammation are frequent and significant complications of both prolonged hyperglycemia and iatrogenic hypoglycemia, the effect of glucose concentration and resveratrol (RSV) supplementation on cytokine profile was assessed in an in vitro model of the blood-brain barrier (BBB). MATERIAL AND METHODS The in vitro model of BBB was formed of endothelial cells and astrocytes, which represented the microvascular and brain compartments (MC and BC, respectively). The BC concentrations of selected cytokines - IL-10, IL-12, IL-17A, TNF-alpha, IFN-γ, GM-CSF in response to different glucose concentrations in the MC were studied. The influence of LPS in the BC and RSV in the MC on the cytokine profile in the BC was examined. RESULTS Low glucose concentration (40 mg/dL) in the MC resulted in increased concentration of all the cytokines in the BC except TNF-alpha, compared to normoglycemia-imitating conditions (90 mg/dL) (P<0.05). High glucose concentration (450 mg/dL) in the MC elevated the concentration of all the cytokines in the BC (P<0.05). RSV decreased the level of all cytokines in the BC after 24 h following its administration for all glucose concentrations in the MC (P<0.02). The greatest decline was observed in normoglycemic conditions (P<0.05). CONCLUSIONS Both hypo- and hyperglycemia-simulating conditions impair the cytokine profile in BC, while RSV can normalize it, despite relatively poor penetration through the BBB. RSV exhibits anti-neuroinflammatory effects, especially in the group with normoglycemia-simulating conditions.

Resveratrol in Neurodegeneration, in Neurodegenerative Diseases, and in the Redox Biology of the Mitochondria

Neurodegeneration is a process leading to the progressive loss of structure and functions of neurons. Many neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease have shown many common points at the subcellular level. Neurons are metabolically active cells and need a high amount of energy. Mitochondria are known as the energy synthesis center for cells, involved in the synthesis of adenosine triphosphate by oxidative phosphorylation. Rather than just being an energy synthesis center, it has critical importance for many cellular functions such as calcium homeostasis, cell proliferation, cell growth, and apoptosis. In the process of mitochondrial dysfunction, cellular functions are disrupted and cells enter the apoptotic or necrotic pathway. Resveratrol (trans-3,5,4-trihydoxystilbene), a plant-derived polyphenol found in the seed of grapes, berries, peanuts, and wine, has many biological effects such as inhibition of lipid peroxidation, scavenging of free radicals, changes in eicosanoid synthesis, inhibition of platelet aggregation, anti-inflammatory and anticancer activity, and regulation of lipid metabolism. Through the reviewed literature, the current study investigated the protective role of resveratrol in neurodegenerative diseases. Studies show that resveratrol moderates mitochondrial function, redox status, and cellular dynamics in both in vivo and in vitro experimental models of neurodegeneration. Resveratrol suppresses reactive oxygen species production by reducing the activity of complex III due to its competition effect with coenzyme Q. In the present work, we discussed the protective effects of resveratrol on neurodegeneration, neurodegenerative diseases, and the redox biology of the mitochondria.

Conjugation, Prodrug, and Co-Administration Strategies in Support of Nanotechnologies to Improve the Therapeutic Efficacy of Phytochemicals in the Central Nervous System

Phytochemicals, produced as secondary plant metabolites, have shown interesting potential therapeutic activities against neurodegenerative diseases and cancer. Unfortunately, poor bioavailability and rapid metabolic processes compromise their therapeutic use, and several strategies are currently proposed for overcoming these issues. The present review summarises strategies for enhancing the central nervous system's phytochemical efficacy. Particular attention has been paid to the use of phytochemicals in combination with other drugs (co-administrations) or administration of phytochemicals as prodrugs or conjugates, particularly when these approaches are supported by nanotechnologies exploiting conjugation strategies with appropriate targeting molecules. These aspects are described for polyphenols and essential oil components, which can improve their loading as prodrugs in nanocarriers, or be part of nanocarriers designed for targeted co-delivery to achieve synergistic anti-glioma or anti-neurodegenerative effects. The use of in vitro models, able to simulate the blood-brain barrier, neurodegeneration or glioma, and useful for optimizing innovative formulations before their in vivo administration via intravenous, oral, or nasal routes, is also summarised. Among the described compounds, quercetin, curcumin, resveratrol, ferulic acid, geraniol, and cinnamaldehyde can be efficaciously formulated to attain brain-targeting characteristics, and may therefore be therapeutically useful against glioma or neurodegenerative diseases.

The effect of polyphenols in post stroke adults: A systematic review of randomised controlled trials

BACKGROUND

After a stroke, survivors are often left with significant disabilities and are at a greater risk of recurrent strokes. It is vital stroke survivors receive effective treatments to assist with rehabilitation and reduce risk factors for secondary stroke. Observational and preclinical studies have highlighted the promising role of polyphenols in these regards.

METHODS

A systematic review of original research which assessed the role of polyphenols on health outcomes in post stroke adults was conducted. PROQUEST, SCOPUS (Elsevier), MEDLINE (EBSCO), Embase and Cochrane Library databases were searched up to the 29th of October 2021.

RESULTS

A total of 9 studies met the full inclusion criteria and were included in this review. Several classes of polyphenols were assessed including hydroxybenzoic acids, stilbenes and flavonoids. Numerous health outcomes were assessed including vascular function, stroke disability, blood pressure, blood glucose and c-reactive protein. The majority of the studies included in this review (n = 8) note improvements in the polyphenol groups for at least one outcome measure. However, small sample sizes, short trial length and reporting bias prevent firm conclusions from being drawn.

CONCLUSION

This review provides promising preliminary evidence that polyphenols may be beneficial for post stroke adults, however, more research is required. To ensure reliable methodology and replication of results, future studies should include outcome statistics and effect sizes. Trials with a longer duration and large sample size should also be considered.

Activities of (Poly)phenolic Antioxidants and Other Natural Autophagy Modulators in the Treatment of Sanfilippo Disease: Remarkable Efficacy of Resveratrol in Cellular and Animal Models

Sanfilippo disease, caused by mutations in the genes encoding heparan sulfate (HS) (a glycosaminoglycan; GAG) degradation enzymes, is a mucopolysaccharidosis (MPS), which is also known as MPS type III, and is characterized by subtypes A, B, C, and D, depending on identity of the dysfunctional enzyme. The lack of activity or low residual activity of an HS-degrading enzyme leads to excess HS in the cells, impairing the functions of different types of cells, including neurons. The disease usually leads to serious psychomotor dysfunction and death before adulthood. In this work, we show that the use of molecules known as dietary (poly)phenolic antioxidants and other natural compounds known as autophagy activators (genistein, capsaicin, curcumin, resveratrol, trehalose, and calcitriol) leads to accelerated degradation of accumulated HS in the fibroblasts of all subtypes of MPS III. Both the cytotoxicity tests we performed and the available literature data indicated that the use of selected autophagy inducers was safe. Since it showed the highest effectivity in cellular models, resveratrol efficacy was tested in experiments with a mouse model of MPS IIIB. Urinary GAG levels were normalized in MPS IIIB mice treated with 50 mg/kg/day resveratrol for 12 weeks or longer. Behavioral tests indicated complete correction of hyperactivity and anxiety in these animals. Biochemical analyses indicated that administration of resveratrol caused autophagy stimulation through an mTOR-independent pathway in the brains and livers of the MPS IIIB mice. These results indicate the potential use of resveratrol (and possibly other autophagy stimulators) in the treatment of Sanfilippo disease.

Are the epigenetic changes predictive of therapeutic efficacy for psychiatric disorders? A translational approach towards novel drug targets

The etiopathogenesis of mental disorders is not fully understood and accumulating evidence support that clinical symptomatology cannot be assigned to a single gene mutation, but it involves several genetic factors. More specifically, a tight association between genes and environmental risk factors, which could be mediated by epigenetic mechanisms, may play a role in the development of mental disorders. Several data suggest that epigenetic modifications such as DNA methylation, post-translational histone modification and interference of microRNA (miRNA) or long non-coding RNA (lncRNA) may modify the severity of the disease and the outcome of the therapy. Indeed, the study of these mechanisms may help to identify patients particularly vulnerable to mental disorders and may have potential utility as biomarkers to facilitate diagnosis and treatment of psychiatric disorders. This article summarizes the most relevant preclinical and human data showing how epigenetic modifications can be central to the therapeutic efficacy of antidepressant and/or antipsychotic agents, as possible predictor of drugs response.

Phytochemistry, Pharmacology and Molecular Mechanisms of Herbal Bioactive Compounds for Sickness Behaviour

The host's response to acute infections or tissue injury is a sophisticated and coordinated adaptive modification called sickness behaviour. Many herbs have been studied for their ability to protect animals against experimentally induced sickness behaviour. However, there is a lack of knowledge and experimental evidence on the use of herbal bioactive compounds (HBACs) in the management of sick behaviour. The goal of this review is to provide a concise summary of the protective benefits and putative mechanisms of action of phytochemicals on the reduction of lipopolysaccharide (LPS)-induced sickness behaviour. Relevant studies were gathered from the search engines Scopus, ScienceDirect, PubMed, Google Scholar, and other scientific databases (between 2000 and to date). The keywords used for the search included "Lipopolysaccharide" OR "LPS" OR "Sickness behaviour" OR "Sickness" AND "Bioactive compounds" OR "Herbal medicine" OR "Herbal drug" OR "Natural products" OR "Isolated compounds". A total of 41 published articles that represented data on the effect of HBACs in LPS-induced sickness behaviour were reviewed and summarised systemically. There were 33 studies that were conducted in mice and 8 studies in rats. A total of 34 HBACs have had their effects against LPS-induced changes in behaviour and biochemistry investigated. In this review, we examined 34 herbal bioactive components that have been tested in animal models to see if they can fight LPS-induced sickness behaviour. Future research should concentrate on the efficacy, safety, and dosage needed to protect against illness behaviour in humans, because there is a critical shortage of data in this area.

Effects of lifespan-extending interventions on cognitive healthspan

Ageing is known to be the primary risk factor for most neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and Huntington's disease. They are currently incurable and worsen over time, which has broad implications in the context of lifespan and healthspan extension. Adding years to life and even to physical health is suboptimal or even insufficient, if cognitive ageing is not adequately improved. In this review, we will examine how interventions that have the potential to extend lifespan in animals affect the brain, and if they would be able to thwart or delay the development of cognitive dysfunction and/or neurodegeneration. These interventions range from lifestyle (caloric restriction, physical exercise and environmental enrichment) through pharmacological (nicotinamide adenine dinucleotide precursors, resveratrol, rapamycin, metformin, spermidine and senolytics) to epigenetic reprogramming. We argue that while many of these interventions have clear potential to improve cognitive health and resilience, large-scale and long-term randomised controlled trials are needed, along with studies utilising washout periods to determine the effects of supplementation cessation, particularly in aged individuals.

Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer's Disease: Dietary Plant Polyphenols

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

Resveratrol Mitigates Oxygen and Glucose Deprivation-Induced Inflammation, NLRP3 Inflammasome, and Oxidative Stress in 3D Neuronal Culture

Oxygen glucose deprivation (OGD) can produce hypoxia-induced neurotoxicity and is a mature in vitro model of hypoxic cell damage. Activated AMP-activated protein kinase (AMPK) regulates a downstream pathway that substantially increases bioenergy production, which may be a key player in physiological energy and has also been shown to play a role in regulating neuroprotective processes. Resveratrol is an effective activator of AMPK, indicating that it may have therapeutic potential as a neuroprotective agent. However, the mechanism by which resveratrol achieves these beneficial effects in SH-SY5Y cells exposed to OGD-induced inflammation and oxidative stress in a 3D gelatin scaffold remains unclear. Therefore, in the present study, we investigated the effect of resveratrol in 3D gelatin scaffold cells to understand its neuroprotective effects on NF-κB signaling, NLRP3 inflammasome, and oxidative stress under OGD conditions. Here, we show that resveratrol improves the expression levels of cell viability, inflammatory cytokines (TNF-α, IL-1β, and IL-18), NF-κB signaling, and NLRP3 inflammasome, that OGD increases. In addition, resveratrol rescued oxidative stress, nuclear factor-erythroid 2 related factor 2 (Nrf2), and Nrf2 downstream antioxidant target genes (e.g., SOD, Gpx GSH, catalase, and HO-1). Treatment with resveratrol can significantly normalize OGD-induced changes in SH-SY5Y cell inflammation, oxidative stress, and oxidative defense gene expression; however, these resveratrol protective effects are affected by AMPK antagonists (Compounds C) blocking. These findings improve our understanding of the mechanism of the AMPK-dependent protective effect of resveratrol under 3D OGD-induced inflammation and oxidative stress-mediated cerebral ischemic stroke conditions.

Modulation of cellular redox environment as a novel therapeutic strategy for Parkinson's disease

Parkinson's disease (PD) is an incurable neurodegenerative movement disorder. PD affects 2% of the population above 65 years old; however, with the growing number of senior citizens, PD prevalence is predicted to increase in the following years. Pathologically, PD is characterized by dopaminergic cell neurodegeneration in the substantia nigra, resulting in decreased dopamine levels in the nigrostriatal pathway, triggering motor symptoms. Although the pathological mechanisms leading to PD are still unclear, large evidence indicates that oxidative stress plays an important role, not only because it increases with age which is the most significant risk factor for PD development, but also as a result of alterations in several processes, particularly mitochondria dysfunction. The modulation of oxidative stress, especially using dietary mitochondriotropic antioxidants, represents a promising approach to prevent or treat PD. Although most mitochondria-targeted antioxidants with beneficial effects in PD-associated models have failed to show any therapeutic benefit in clinical trials, several questions remain to be clarified. Hereby, we review the role played by oxidative stress in PD pathogenesis, emphasizing mitochondria as reactive oxygen species (ROS) producers and as targets for oxidative stress-related dysfunctional mechanisms. In addition, we also describe the importance of using dietary-based mitochondria-targeted antioxidants as a valuable strategy to counteract the deleterious effects of ROS in pre-clinical and/or clinical trials of PD, pointing out their significance to slow, and possibly halt, the progression of PD.

Resveratrol: A potential therapeutic natural polyphenol for neurodegenerative diseases associated with mitochondrial dysfunction

Most polyphenols can cross blood-brain barrier, therefore, they are widely utilized in the treatment of various neurodegenerative diseases (ND). Resveratrol, a natural polyphenol contained in blueberry, grapes, mulberry, etc., is well documented to exhibit potent neuroprotective activity against different ND by mitochondria modulation approach. Mitochondrial function impairment is the most common etiology and pathological process in various neurodegenerative disorders, viz. Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and amyotrophic lateral sclerosis. Nowadays these ND associated with mitochondrial dysfunction have become a major threat to public health as well as health care systems in terms of financial burden. Currently available therapies for ND are limited to symptomatic cures and have inevitable toxic effects. Therefore, there is a strict requirement for a safe and highly effective drug treatment developed from natural compounds. The current review provides updated information about the potential of resveratrol to target mitochondria in the treatment of ND.

Native PLGA nanoparticles regulate APP metabolism and protect neurons against β-amyloid toxicity: Potential significance in Alzheimer's disease pathology

Biodegradable poly(lactic-co-glycolic acid)(PLGA) nanoparticles have been used extensively in delivering drugs to target tissues due to their excellent biocompatibility. Evidence suggests that PLGA-conjugated drugs/agents can attenuate pathology in cellular/animal models of Alzheimer's disease (AD), which is initiated by increased level/aggregation of amyloid β (Aβ) peptide generated from amyloid precursor protein (APP). The beneficial effects were attributed to conjugated-drugs rather than to PLGA nanoparticles. Interestingly, we recently reported that PLGA without any drug/agent (native PLGA) can suppress Aβ aggregation/toxicity. However, very little is known about the internalization, subcellular localization or effects of PLGA in neurons. In this study, using primary mouse cortical neurons, we first showed that native PLGA is internalized by an energy-mediated clathrin-dependent/-independent pathway and is localized in endosomal-lysosomal-autophagic vesicles. By attenuating internalization, PLGA can protect neurons against Aβ-mediated toxicity. Additionally, PLGA treatment altered expression profiles of certain AD-associated genes and decreased the levels of APP, its cleaved products α-/β-CTFs and Aβ peptides in mouse as well as iPSC-derived neurons from control and AD patients. Collectively, these results suggest that native PLGA not only protects neurons against Aβ-induced toxicity but also influences the expression of AD-related genes/proteins - highlighting PLGA's implication in normal and AD-related pathology.

Protective Effect of Resveratrol on Knee Osteoarthritis and its Molecular Mechanisms: A Recent Review in Preclinical and Clinical Trials

Osteoarthritis (OA) is one of the progressing chronic joint associated with by many complex factors such as age, obesity, and trauma. Knee osteoarthritis (KOA) is the most common type of OA. KOA is characterized by articular cartilage destruction and degeneration, synovial inflammation, and abnormal subchondral bone changes. To date, no practical clinical approach has been able to modify the pathological progression of KOA. Drug therapy is limited to pain control and may lead to serious side effects when taken for a long time. Therefore, searching for safer and more reliable treatments has become necessary. Interestingly, more and more research has focused on natural products, and monomeric compounds derived from natural products have received much attention as drug candidates for KOA treatment. Resveratrol (RES), a natural phenolic compound, has various pharmacological and biological activities, including anti-cancer, anti-apoptotic, and anti-decay. Recently, studies on the effects of RES on maintaining the normal homeostasis of chondrocytes in KOA have received increasing attention, which seems to be attributed to the multi-targeted effects of RES on chondrocyte function. This review summarizes preclinical trials, clinical trials, and emerging tissue engineering studies of RES for KOA and discusses the specific mechanisms by which RES alleviates KOA. A better understanding of the pharmacological role of RES in KOA could provide clinical implications for intervention in the development of KOA.

Thermosensitive Hydrogels Loaded with Resveratrol Nanoemulsion: Formulation Optimization by Central Composite Design and Evaluation in MCF-7 Human Breast Cancer Cell Lines

The second most common cause of mortality among women is breast cancer. A variety of natural compounds have been demonstrated to be beneficial in the management of various malignancies. Resveratrol is a promising anticancer polyphenolic compound found in grapes, berries, etc. Nevertheless, its low solubility, and hence its low bioavailability, restrict its therapeutic potential. Therefore, in our study, we developed a thermosensitive hydrogel formulation loaded with resveratrol nanoemulsion to enhance its bioavailability. Initially, resveratrol nanoemulsions were formulated and optimized utilizing a central composite-face-centered design. The independent variables for optimization were surfactant level, homogenization speed, and time, while the size and zeta potential were the dependent variables. The optimized nanoemulsion formulation was converted into a sensitive hydrogel using poloxamer 407. Rheological studies proved the formation of gel consistency at physiological temperature. Drug loading efficiency and in vitro drug release from gels were also analyzed. The drug release mechanisms from the gels were assessed using various mathematical models. The effect of the optimized thermosensitive resveratrol nanoemulsion hydrogel on the viability of human breast cancer cells was tested using MCF-7 cancer cell lines. The globule size of the selected formulation was 111.54 ± 4.16 nm, with a zeta potential of 40.96 ± 3.1 mV. Within 6 h, the in vitro release profile demonstrated a release rate of 80%. According to cell line studies, the produced hydrogel of resveratrol nanoemulsion was cytotoxic to breast cancer cells. Overall, the results proved the developed nanoemulsion-loaded thermosensitive hydrogel is a promising platform for the effective delivery of resveratrol for the management of breast cancer.

Targeting autophagy and neuroinflammation pathways with plant-derived natural compounds as potential antidepressant agents

Major depressive disorder (MDD) is a life-threatening disease that presents several characteristics. The pathogenesis of depression still remains poorly understood. Moreover, the mechanistic interactions of natural components in treating depression to target autophagy and neuroinflammation are yet to be evaluated. This study overviewed the effects of plant-derived natural components in regulating critical pathways, particularly neuroinflammation and autophagy, associated with depression. A list of natural components, including luteolin, apigenin, hyperforin, resveratrol, salvianolic acid b, isoliquiritin, nobiletin, andrographolide, and oridonin, have been investigated. All peer-reviewed journal articles were searched by Scopus, MEDLINE, PubMed, Web of Science, and Google Scholar using the appropriated keywords, including depression, neuroinflammation, autophagy, plant, natural components, etc. The neuroinflammation and autophagy dysfunction are critically associated with the pathophysiology of depression. Natural components with higher efficiency and lower complications can be used for targeting neuroinflammation and autophagy. These components with different doses showed the beneficial antidepressant properties in rodents. These can modulate autophagy markers, mainly AMPK, LC3II/LC3I ratio, Beclin-1. Moreover, they can regulate the NLRP3 inflammasome, resulting in the suppression of proinflammatory cytokines (e.g., IL-1β and IL-18). Future in vitro and in vivo studies are required to develop novel therapeutic approaches based on plant-derived active components to treat MDD.

Evaluation of Resveratrol and Piceatannol Anticonvulsant Potential in Adult Zebrafish (Danio rerio)

Epilepsy is a common neurological disorder which affects 50 million people worldwide. Patients with epilepsy may present cognitive deficits and psychological impairment. Currently, 30% of patients fail to respond to any available antiseizure drug, and a significant number of patients do not well tolerate the offered treatments. Then, it is necessary to find out alternatives for controlling epileptic seizures. Studies have shown that despite its neuroprotective effects, resveratrol shows poor anticonvulsant properties. Resveratrol analog, piceatannol, possesses higher biological activity than resveratrol and could be an alternative to control seizure. Thus, the present study investigated the effects of resveratrol and piceatannol in pentylenetetrazole-induced seizures in adult zebrafish (Danio rerio). Only the experimental positive control (diazepam) showed anticonvulsant effect in this study. In addition, no behavioral changes were observed 24 h after seizure occurrence. Finally, the expression of genes related to neuronal activity (c-fos), neurogenesis (p70S6Ka and p70S6Kb), inflammatory response (interleukin 1β), and cell apoptosis (caspase-3) did not change by pentylenetetrazole-induced seizures. Therefore, we failed to observe any anticonvulsant and neuroprotective potential of resveratrol and piceatannol in adult zebrafish. However, resveratrol and piceatannol benefits in epilepsy are not discharged, and more studies are necessary.

Exploring the Therapeutic Potential of Phytochemicals in Alzheimer’s Disease: Focus on Polyphenols and Monoterpenes

Alzheimer’s disease (AD) is a chronic, complex neurodegenerative disorder mainly characterized by the irreversible loss of memory and cognitive functions. Different hypotheses have been proposed thus far to explain the etiology of this devastating disorder, including those centered on the Amyloid-β (Aβ) peptide aggregation, Tau hyperphosphorylation, neuroinflammation and oxidative stress. Nonetheless, the therapeutic strategies conceived thus far to treat AD neurodegeneration have proven unsuccessful, probably due to the use of single-target drugs unable to arrest the progressive deterioration of brain functions. For this reason, the theoretical description of the AD etiology has recently switched from over-emphasizing a single deleterious process to considering AD neurodegeneration as the result of different pathogenic mechanisms and their interplay. Moreover, much relevance has recently been conferred to several comorbidities inducing insulin resistance and brain energy hypometabolism, including diabetes and obesity. As consequence, much interest is currently accorded in AD treatment to a multi-target approach interfering with different pathways at the same time, and to life-style interventions aimed at preventing the modifiable risk-factors strictly associated with aging. In this context, phytochemical compounds are emerging as an enormous source to draw on in the search for multi-target agents completing or assisting the traditional pharmacological medicine. Intriguingly, many plant-derived compounds have proven their efficacy in counteracting several pathogenic processes such as the Aβ aggregation, neuroinflammation, oxidative stress and insulin resistance. Many strategies have also been conceived to overcome the limitations of some promising phytochemicals related to their poor pharmacokinetic profiles, including nanotechnology and synthetic routes. Considering the emerging therapeutic potential of natural medicine, the aim of the present review is therefore to highlight the most promising phytochemical compounds belonging to two major classes, polyphenols and monoterpenes, and to report the main findings about their mechanisms of action relating to the AD pathogenesis.

Phytochemicals Targeting Oxidative Stress, Interconnected Neuroinflammatory, and Neuroapoptotic Pathways Following Radiation

The radiation for therapeutic purposes has shown positive effects in different contexts; however, it can increase the risk of many age-related and neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and Parkinson's disease (PD). These different outcomes highlight a dose-response phenomenon called hormesis. Prevailing studies indicate that high doses of radiation could play several destructive roles in triggering oxidative stress, neuroapoptosis, and neuroinflammation in neurodegeneration. However, there is a lack of effective treatments in combating radiation-induced neurodegeneration, and the present drugs suffer from some drawbacks, including side effects and drug resistance. Among natural entities, polyphenols are suggested as multi-target agents affecting the dysregulated pathogenic mechanisms in neurodegenerative disease. This review discusses the destructive effects of radiation on the induction of neurodegenerative diseases by dysregulating oxidative stress, apoptosis, and inflammation. We also describe the promising effects of polyphenols and other candidate phytochemicals in preventing and treating radiation-induced neurodegenerative disorders, aiming to find novel/potential therapeutic compounds against such disorders.

Trans-resveratrol electrochemical detection using portable device based on unmodified screen-printed electrode

Trans-resveratrol (t-RESV) is an important and natural polyphenolic antioxidant generally found in grapes and in its derivatives such as red wine and grape juices. The t-RESV has been explored in the pharmaceutical industry for its anti-inflammatory, anti-cancer, and neuroprotective properties. The t-RESV electrochemical determination has basically been carried out using modified electrodes-based sensors. Although these devices show good analytical performance, the electrode preparation can be laborious, and the devices may lack reproducibility. In this sense, it was proposed here a new methodology for the t-RESV electrochemical detection using unmodified screen-printed electrodes and differential pulse voltammetry (DPV). The response of the anodic signal has optimized varying the most important parameters of DPV (pulse time, pulse potential, and pulse step) using the response surface methodology. We showed based on analysis of variance that the new mathematical model developed can predict responses for the t-RESV using DPV. Furthermore, the new analytical method was validated from the limits of detection and quantification. We have still shown that t-RESV can be quantified in commercial drug using DPV with the optimized parameters. The selectivity test also showed that the sensor can be used to determine the antioxidant in other more complex matrices. Additionally, the proposed electrochemical system is completely portable and can work with its own energy, which facilitates point-of-care analysis.

Plasmalogen Replacement Therapy

Plasmalogens, a subclass of glycerophospholipids containing a vinyl-ether bond, are one of the major components of biological membranes. Changes in plasmalogen content and molecular species have been reported in a variety of pathological conditions ranging from inherited to metabolic and degenerative diseases. Most of these diseases have no treatment, and attempts to develop a therapy have been focusing primarily on protein/nucleic acid molecular targets. However, recent studies have shifted attention to lipids as the basis of a therapeutic strategy. In these pathological conditions, the use of plasmalogen replacement therapy (PRT) has been shown to be a successful way to restore plasmalogen levels as well as to ameliorate the disease phenotype in different clinical settings. Here, the current state of PRT will be reviewed as well as a discussion of future perspectives in PRT. It is proposed that the use of PRT provides a modern and innovative molecular medicine approach aiming at improving health outcomes in different conditions with clinically unmet needs.

Molecular mechanisms of resveratrol and EGCG in the inhibition of Aβ42 aggregation and disruption of Aβ42 protofibril: similarities and differences

The aggregation of amyloid-β protein (Aβ) into fibrillary deposits is implicated in Alzheimer's disease (AD), and inhibiting Aβ aggregation and clearing Aβ fibrils are considered as promising strategies to treat AD. It has been reported that resveratrol (RSV) and epigallocatechin-3-gallate (EGCG), two of the most extensively studied natural polyphenols, are able to inhibit Aβ fibrillization and remodel the preformed fibrillary aggregates into amorphous, non-toxic species. However, the mechanisms by which RSV inhibits Aβ₄₂ aggregation and disrupts Aβ₄₂ protofibril, as well as the inhibitory/disruptive mechanistic similarities and differences between RSV and EGCG, remain mostly elusive. Herein, we performed extensive all-atom molecular dynamics (MD) simulations on Aβ₄₂ dimers (the early aggregation state of Aβ₄₂) and protofibrils (the intermediate of Aβ₄₂ fibril formation and elongation) in the absence/presence of RSV or EGCG molecules. Our simulations show that both RSV and EGCG can bind with Aβ₄₂ monomers and inhibit the dimerization of Aβ₄₂. The binding of RSV with Aβ₄₂ peptide is mostly viaπ-π stacking interactions, while the binding of EGCG with Aβ₄₂ is mainly through hydrophobic, π-π stacking, and hydrogen-bonding interactions. Moreover, both RSV and EGCG disrupt the β-sheet structure and K28-A42 salt bridges, leading to a disruption of Aβ₄₂ protofibril structure. RSV mainly binds with residues whose side-chains point inwards from the surface of the protofibril, while EGCG mostly binds with residues whose side-chains point outwards from the surface of the protofibril. Furthermore, RSV interacts with Aβ₄₂ protofibrils mostly viaπ-π stacking interactions, while EGCG interacts with Aβ₄₂ protofibrils mainly via hydrogen-bonding and hydrophobic interactions. For comparison, we also explore the effects of RSV/EGCG molecules on the aggregation inhibition and protofibril disruption of the Iowa mutant (D23N) Aβ. Our findings may pave the way for the design of more effective drug candidates as well as the utilization of cocktail therapy using RSV and EGCG for the treatment of AD.

Neuroprotective Effects of Resveratrol in Ischemic Brain Injury

Cerebral ischemia represents the third cause of death and the first cause of disability in adults. This process results from decreasing cerebral blood flow levels as a result of the occlusion of a major cerebral artery. This restriction in blood supply generates low levels of oxygen and glucose, which leads to a decrease in the energy metabolism of the cell, producing inflammation, and finally, neurological deterioration. Currently, blood restoration of flow is the only effective approach as a therapy in terms of ischemic stroke. However, a significant number of patients still have a poor prognosis, probably owing to the increase in the generation of reactive oxygen species (ROS) during the reperfusion of damaged tissue. Oxidative stress and inflammation can be avoided by modulating mitochondrial function and have been identified as potential targets for the treatment of cerebral ischemia. In recent years, the beneficial actions of flavonoids and polyphenols against cerebrovascular diseases have been extensively investigated. The use of resveratrol (RSV) has been shown to markedly decrease brain damage caused by ischemia in numerous studies. According to in vitro and in vivo experiments, there is growing evidence that RSV is involved in several pathways, including cAMP/AMPK/SIRT1 regulation, JAK/ERK/STAT signaling pathway modulation, TLR4 signal transduction regulation, gut/brain axis modulation, GLUT3 up-regulation inhibition, neuronal autophagy activation, and de novo SUR1 expression inhibition. In this review, we summarize the recent outcomes based on the neuroprotective effect of RSV itself and RSV-loaded nanoparticles in vitro and in vivo models focusing on such mechanisms of action as well as describing the potential therapeutic strategies in which RSV plays an active role in cases of ischemic brain injury.

Resveratrol inhibits inflammation after spinal cord injury via SIRT-1/NF-κB signaling pathway

Spinal cord injury (SCI) can cause severe trauma to the central nervous system. Resveratrol has been widely studied for several of its medicinal properties, including anti-inflammatory, anti-aging and anti-oxidative effects. The regulation of SIRT-1 is thought to be related to the effects of resveratrol. As a downstream component of SIRT-1, NF-κB is one of the important signaling pathways that regulate the inflammatory response. Herein, we explored how treatment with resveratrol promoted recovery of motor function after SCI by activating the SIRT-1/NF-κB signaling pathway and inhibiting inflammation in rat models. Recovery of hind limb function was observed using the Basso, Beattie, and Bresnahan locomotor rating scale at different time points after SCI. Western blot analysis, immunofluorescence, Nissl staining and HE staining were utilized to observe the morphological characteristics of spinal cord tissue, as well as the expression of SIRT-1, NF-κB, TNF-α, IL-1β, IL-6 and brain-derived neurotrophic factor. Resveratrol treatment promoted motor function recovery, increased the expression of brain-derived neurotrophic factor, and reduced loss of motor neurons and lesion size among rats after SCI. Meanwhile, inflammatory response was inhibited as the SIRT-1/NF-κB signaling pathway was modulated. These results suggest that resveratrol can help achieve neuroprotective effect by inhibiting inflammation, regulated by the SIRT-1/NF-κB signaling pathway.

Resveratrol Relieves Hyperoxia-Induced Brain Injury in Neonatal Rats by Activating Sirt1

OBJECTIVE

Neonatal rats with hyperoxia-induced brain injury were treated with resveratrol to investigate its protective effects through analyzing changes in reactive oxygen species (ROS), Sirt1, p53, and acetylated p53 levels.

STUDY DESIGN

Neonatal rats were randomly divided into hyperoxia and resveratrol intervened groups. Rats in both groups were placed in a hyperoxia chamber for 7 days to induce hyperoxia-induced brain injury. The rats in the resveratrol intervened group were administered resveratrol 60 μg/g body weight daily, whereas those in the hyperoxia group were administered a dimethyl sulfoxide-based solvent. Brain tissues were collected, and hematoxylin and eosin (H&E) and TUNEL staining, ROS measurements, real time-polymerase chain reaction, and western blotting were performed.

RESULTS

H&E and TUNEL staining revealed increased cell damage and apoptosis in brain tissue from hyperoxia-exposed animals compared with the findings in animals in the resveratrol intervened group. Real time-polymerase chain reaction and western blotting identified increases in Sirt1 expression and decreases in p53 expression in the resveratrol intervened group. In addition, acetylated p53 protein expression was lower in the intervened group than in the hyperoxia group.

CONCLUSION

Resveratrol alleviated brain apoptosis induced by hyperoxia in neonatal rats by upregulating Sirt1-mediated pathways, suggesting its potentially beneficial role in the treatment of brain injury induced by hyperoxia.

Oxidative Stress, Mitochondrial Dysfunction, and Neuroprotection of Polyphenols with Respect to Resveratrol in Parkinson's Disease

Parkinson’s disease (PD) is the second most common neurodegenerative disease and is characterized by dopaminergic neuronal loss. The exact pathogenesis of PD is complex and not yet completely understood, but research has established the critical role mitochondrial dysfunction plays in the development of PD. As the main producer of cytosolic reactive oxygen species (ROS), mitochondria are particularly susceptible to oxidative stress once an imbalance between ROS generation and the organelle’s antioxidative system occurs. An overabundance of ROS in the mitochondria can lead to mitochondrial dysfunction and further vicious cycles. Once enough damage accumulates, the cell may undergo mitochondria-dependent apoptosis or necrosis, resulting in the neuronal loss of PD. Polyphenols are a group of natural compounds that have been shown to offer protection against various diseases, including PD. Among these, the plant-derived polyphenol, resveratrol, exhibits neuroprotective effects through its antioxidative capabilities and provides mitochondria protection. Resveratrol also modulates crucial genes involved in antioxidative enzymes regulation, mitochondrial dynamics, and cellular survival. Additionally, resveratrol offers neuroprotective effects by upregulating mitophagy through multiple pathways, including SIRT-1 and AMPK/ERK pathways. This compound may provide potential neuroprotective effects, and more clinical research is needed to establish the efficacy of resveratrol in clinical settings.

Impact of dietary polyphenols on neuroinflammation-associated disorders

Neurodegenerative disorders like Alzheimer's, Parkinson's, and associated dementia typically originate with altered protein folding and aggregation of their β structures in the neurons. This self-aggregation leads to glial activation in the brain, causing neuroinflammation and leads to neuronal death. According to statistics provided by WHO, there are around 50 million people with dementia worldwide and every year, 10 million more cases are projected to increase. Also, around 5-8 percentage of people who are aged above 60 globally has dementia or associated disorders. Over 82 million in 2030 and 152 in 2050 are expected to have dementia. Most of these patients fall into low-middle-income countries which makes it even more essential to find an affordable and effective treatment method. Polyphenols of different origin are studied for their potential role as anti-neuro-inflammatory molecules. This review would summarize recent advances in three widely researched dietary polyphenols projected as potential therapeutic agents for disorders like Alzheimer's, Parkinson's, etc. They are Resveratrol, Catechins, and Tannins. The review would discuss the recent advances and challenges in using these polyphenols using specific examples as potential therapeutic agents against neuroinflammation associated disorders. An abstract of neuroinflammation-associated events and the effects by selected polyphenols.

Revisiting the role of mitochondria in spinal muscular atrophy

Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease of variable clinical severity that is caused by mutations in the survival motor neuron 1 (SMN1) gene. Despite its name, SMN is a ubiquitous protein that functions within and outside the nervous system and has multiple cellular roles in transcription, translation, and proteostatic mechanisms. Encouragingly, several SMN-directed therapies have recently reached the clinic, albeit this has highlighted the increasing need to develop combinatorial therapies for SMA to achieve full clinical efficacy. As a subcellular site of dysfunction in SMA, mitochondria represents a relevant target for a combinatorial therapy. Accordingly, we will discuss our current understanding of mitochondrial dysfunction in SMA, highlighting mitochondrial-based pathways that offer further mechanistic insights into the involvement of mitochondria in SMA. This may ultimately facilitate translational development of targeted mitochondrial therapies for SMA. Due to clinical and mechanistic overlaps, such strategies may also benefit other motor neuron diseases and related neurodegenerative disorders.

Polyphenols: Natural compounds with promising potential in treating polycystic ovary syndrome

Polyphenols are natural compounds used by plants as a defense system against various stresses. In recent years, the importance of these polyhydroxyphenols has extensively increased due to their potent cardioprotection, anti-carcinogenic, anti-oxidant, anti-apoptotic, and anti-inflammatory properties. Therefore, various studies have reported promising results from the studies investigating their efficacy as a therapeutic strategy in various disorders such as human malignancies, cardiovascular diseases, nervous system impairments, diabetes, metabolic syndrome, aging, and inflammation-associated disorders, as well as a polycystic ovarian syndrome (PCOS). Since oxidative stress, hormonal, metabolic, and endocrine disturbances have been shown to play a crucial role in the initiation/progression of PCOS, polyphenols are suggested to be an effective treatment for this disorder. Therefore, this study aimed to discuss the therapeutic potential of multiple polyphenols in PCOS.

Coconut oil-based resveratrol nanoemulsion: Optimization using response surface methodology, stability assessment and pharmacokinetic evaluation

Phytochemicals are widely studied for therapeutic applications and nanostructured delivery systems for phytochemicals are under spotlight. Resveratrol is a promising candidate for neurodegenerative disorders. In the present study, we aimed to formulate nanoemulsion of resveratrol by ultrasonication process using response surface methodology. The effect of both formulation and ultrasonication process factors were studied for the nanoemulsification process using coconut oil, Pluronic-P107, and Cremophor EL. The time, intensity, and power of ultrasonication were selected as process factors. The globule size, PDI, and zeta potential were the responses selected. The concentrations of oil and surfactant and the intensity were found to significantly influence the globule size. The concentration of resveratrol in the optimized nanoemulsion formulation was 2.6442 mg/ml. The in vitro drug release in pH 6.8 phosphate buffer as well as in vitro permeation study on goat nasal mucosa proved the superiority of the nanoemulsion formulation. On intranasal administration in the rat at a resveratrol dose of 2 mg/kg, the brain targeting efficacy of the nanoemulsion formulation was high. Overall, this research provides the benefit of intake of resveratrol containing fruits and, its incorporation into nanoemulsions system could be a promising alternative for the management of Alzheimer's disease.

Liposomes: Novel Drug Delivery Approach for Targeting Parkinson's Disease

Parkinson's disease is one of the most severe progressive neurodegenerative disorders, having a mortifying effect on the health of millions of people around the globe. The neural cells producing dopamine in the substantia nigra of the brain die out. This leads to symptoms like hypokinesia, rigidity, bradykinesia, and rest tremor. Parkinsonism cannot be cured, but the symptoms can be reduced with the intervention of medicinal drugs, surgical treatments, and physical therapies. Delivering drugs to the brain for treating Parkinson's disease is very challenging. The blood-brain barrier acts as a highly selective semi-permeable barrier, which refrains the drug from reaching the brain. Conventional drug delivery systems used for Parkinson's disease do not readily cross the blood barrier and further lead to several side-effects. Recent advancements in drug delivery technologies have facilitated drug delivery to the brain without flooding the bloodstream and by directly targeting the neurons. In the era of Nanotherapeutics, liposomes are an efficient drug delivery option for brain targeting. Liposomes facilitate the passage of drugs across the blood-brain barrier, enhances the efficacy of the drugs, and minimize the side effects related to it. The review aims at providing a broad updated view of the liposomes, which can be used for targeting Parkinson's disease.

Role of natural products for the treatment of Alzheimer's disease

Negative psychological and physiological consequences of neurodegenerative disorders represent a high social and health cost. Among the neurodegenerative disorders Alzheimer's disease (AD) is recognized as a leading neurodegenerative condition and a primary cause of dementia in the elderlys. AD is considered as neurodegenerative disorder that progressively impairs cognitive function and memory. According to current epidemiological data, about 50 milLion people worldwide are suffering from AD. The primary symptoms of AD are almost inappreciable and usually comprise forgetfulness of recent events. Numerous processes are involved in the development of AD, for example oxidative stress (OS) mainly due to mitochondrial dysfunction, intracellular the accumulation of hyperphosphorylated tau (τ) proteins in the form of neurofibrillary tangles, excessive the accumulation of extracellular plaques of beta-amyloid (Aβ), genetic and environmental factors. Running treatments only attenuate symptoms and temporarily reduce the rate of cognitive progression associated with AD. This means that most treatments focus only on controlLing symptoms, particularly in the initial stages of the disease. In the past, the first choice of treatment was based on natural ingredients. In this sense, diverse natural products (NPs) are capable to decrease the symptoms and alleviate the development of several diseases including AD attracting the attention of the scientific community and the pharmaceutical industry. Specifically, numerous NPs including flavonoids, gingerols, tannins, anthocyanins, triterpenes and alkaloids have been shown anti-inflammatory, antioxidant, anti-amyloidogenic, and anti-choLinesterase properties. This review provide a summary of the pathogenesis and the therapeutic goals of AD. It also discusses the available data on various plants and isolated natural compounds used to prevent and diminish the symptoms of AD.