Neuroprotective Properties of Resveratrol and Its Derivatives-Influence on Potential Mechanisms Leading to the Development of Alzheimer's Disease

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

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

Resveratrol and Extra Virgin Olive Oil: Protective Agents Against Age-Related Disease

Resveratrol and extra virgin olive oil are both recognized for their potential protective effects against age-related diseases. This overview highlights their mechanisms of action, health benefits, and the scientific evidence supporting their roles in promoting longevity and cognitive health. A literature search was conducted. Important findings related to the health benefits, mechanisms of action, and clinical implications of resveratrol and EVOO were summarized. Both resveratrol and EVOO have complementary mechanisms that may enhance their anti-aging effects. Resveratrol and EVOO are promising age-related disease-protective agents. Their antioxidant, anti-inflammatory, and neuroprotective properties contribute to improved health outcomes and longevity. Incorporating these compounds into a balanced diet may offer significant benefits for aging populations, supporting cognitive health and reducing the risk of chronic diseases. Continued research is essential to fully understand their mechanisms and optimize their use in clinical settings. Future research should focus on investigating the synergistic effects of resveratrol and EVOO when consumed together, as they may enhance each other's bioavailability and efficacy in promoting health; conducting extensive clinical trials to confirm the long-term benefits of these compounds in various populations, particularly in aging individuals; further exploring the molecular pathways through which resveratrol and EVOO exert their effects, including their interactions with gut microbiota and metabolic pathways.

Latest Perspectives on Alzheimer's Disease Treatment: The Role of Blood-Brain Barrier and Antioxidant-Based Drug Delivery Systems

There has been a growing interest recently in exploring the role of the blood-brain barrier (BBB) in the treatment of Alzheimer's disease (AD), a neurodegenerative disorder characterized by cognitive decline and memory loss that affects millions of people worldwide. Research has shown that the BBB plays a crucial role in regulating the entry of therapeutics into the brain. Also, the potential benefits of using antioxidant molecules for drug delivery were highlighted in Alzheimer's treatment to enhance the therapeutic efficacy and reduce oxidative stress in affected patients. Antioxidant-based nanomedicine shows promise for treating AD by effectively crossing the BBB and targeting neuroinflammation, potentially slowing disease progression and improving cognitive function. Therefore, new drug delivery systems are being developed to overcome the BBB and improve the delivery of therapeutics to the brain, ultimately improving treatment outcomes for AD patients. In this context, the present review provides an in-depth analysis of recent advancements in AD treatment strategies, such as silica nanoparticles loaded with curcumin, selenium nanoparticles loaded with resveratrol, and many others, focusing on the critical role of the BBB and the use of antioxidant-based drug delivery systems.

Effects of association between resveratrol and ketamine on behavioral and biochemical analysis in mice

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a phenol commonly found in grapes and wine, has been associated as protective in experimental models involving alterations in different neurotransmitter systems. However, studies are reporting that resveratrol could have adverse effects. This study evaluated if the association of a low dose of ketamine and resveratrol could induce behavioral manifestations associated with biochemical alterations. Moreover, the effects of treatment with resveratrol and/or ketamine on monoamine oxidase (MAO) activity, oxidative stress markers, and IL-6 levels in the brain were also investigated. Male Swiss mice received a low dose of ketamine (20 mg/kg) for 14 consecutive days, and resveratrol (10, 30, or 100 mg/kg) from day 8 up to day 14 of the experimental period, intraperitoneally. Locomotor, stereotyped behavior, Y-maze, novel recognition object test (NORT), and social interaction were quantified as well as ex vivo analysis of MAO activity, IL-6 levels, and oxidative stress markers (TBARS and total thiol levels) in brain tissues. Ketamine per se reduced the number of bouts of stereotyped behavior on day 8 of the experimental period. Resveratrol per se reduced the locomotor and exploratory activity in the open field, the time of exploration of new objects in the NORT, MAO-A activity in the striatum and increased the IL-6 levels in the cortex. These effects were attenuated when the mice were co-treated with ketamine and resveratrol. There was a decrease in MAO-A activity in the cortex of mice treated with ketamine + resveratrol 100 mg/kg. No significant alterations were found in oxidative stress markers. Resveratrol does not appear to cause summative effects with ketamine on behavioral alterations. However, the effect of resveratrol per se, mainly on locomotor and exploratory activity, should be better investigated.

Optimization of process conditions for ionic liquid-based ultrasound-enzyme-assisted extraction of resveratrol from Polygonum Cuspidatum

This work offered a productive technique for resveratrol extraction from Polygonum Cuspidatum (P. Cuspidatum) using ionic liquids in synergy with ultrasound-enzyme-assisted extraction (UEAE). Firstly, ionic liquids with different carbon chains and anions were evaluated. Subsequently, a comprehensive investigation was carried out to evaluate the effect of seven crucial parameters on the resveratrol yield: pH value, enzyme concentration, extraction temperature, extraction time, ultrasonic power, concentration of ionic liquid (IL concentration) and the liquid-solid ratio. Employing the Plackett-Burman Design (PBD), the critical factors were effectively identified. Building upon this foundation, the process was further optimized through the application of Response Surface Methodology (RSM) and an Artificial Neural Network-Genetic Algorithm (ANN-GA). The following criteria were determined to be the ideal extraction conditions: an enzyme concentration of 2.18%, extraction temperature of 58 °C, a liquid-solid ratio of 29 mL/g, pH value of 5.5, extraction time of 30 min, ultrasonic power of 250 W, and extraction solvent of 0.5 mol/L 1-butyl-3-methylimidazolium bromide. Under these conditions, the resveratrol yield was determined to be 2.90 ± 0.15 mg/g. Comparative analysis revealed that the ANN-GA model provided a better fit to the experimental data of resveratrol yield than the RSM model, suggesting superior predictive capabilities of the ANN-GA approach. The introduction of a novel green solvent system in this experiment not only simplifies the extraction process but also enhances safety and feasibility. This research paves the way for innovative approaches to extracting resveratrol from botanical sources, showcasing its significant potential for a wide range of applications.

Outcome of resveratrol and resveratrol with donepezil combination on the β-amyloid plaques and neurofibrillary tangles in Alzheimer's disease

The goal of this research was to study the effect of different doses of resveratrol (RS) and RS with donepezil (DPZ) on the deposition of amyloid beta (Aβ) and neurofibrillary tangles (NFTs) in colchicine-induced Alzheimer's disease (AD) brain. The study included three months old male Albino Wistar rats and consisted of six animal groups: AD model (group 1), treatment groups, RS 10 mg/kg body weight (group 2), RS 20 mg/kg body weight (group 3), RS 10 mg/kg body weight along with DPZ 1 mg/kg body weight (group 6), prophylaxis groups, RS 10 mg/kg body weight (group 4) and RS 20 mg/kg body weight (group 5). In the treatment groups, RS was given for 7 consecutive days from the day of induction of AD, and in the prophylaxis groups, we started RS 7 days even before the induction of AD and continued for seven days after the induction. The number of Aβs and NFTs at the frontal region, cornu ammonis (CA) 1,2,3,4 and dentate gyrus regions of hippocampus were evaluated. The immunohistochemical analysis was performed by using mouse anti-β-amyloid antibody for the Aβ plaques and polyclonal rabbit anti-human tau for the tau-positive neurons. The present study observed the accumulation of Aβ plaques and tau-positive neurons in the AD model. However, their numbers were significantly decreased in the treatment groups (p < 0.001). The best results were observed when RS 10 mg was given prophylactically (p < 0.01) and RS along with DPZ (p < 0.001), suggesting the neuroprotective effect of RS and its synergistic effect with the DPZ.

Phytonutrients in the promotion of healthspan: a new perspective

Considering a growing, aging population, the need for interventions to improve the healthspan in aging are tantamount. Diet and nutrition are important determinants of the aging trajectory. Plant-based diets that provide bioactive phytonutrients may contribute to offsetting hallmarks of aging and reducing the risk of chronic disease. Researchers now advocate moving toward a positive model of aging which focuses on the preservation of functional abilities, rather than an emphasis on the absence of disease. This narrative review discusses the modulatory effect of nutrition on aging, with an emphasis on promising phytonutrients, and their potential to influence cellular, organ and functional parameters in aging. The literature is discussed against the backdrop of a recent conceptual framework which describes vitality, intrinsic capacity and expressed capacities in aging. This aims to better elucidate the role of phytonutrients on vitality and intrinsic capacity in aging adults. Such a review contributes to this new scientific perspective-namely-how nutrition might help to preserve functional abilities in aging, rather than purely offsetting the risk of chronic disease.

Natural Compounds for Preventing Age-Related Diseases and Cancers

Aging is a multifaceted process influenced by hereditary factors, lifestyle, and environmental elements. As time progresses, the human body experiences degenerative changes in major functions. The external and internal signs of aging manifest in various ways, including skin dryness, wrinkles, musculoskeletal disorders, cardiovascular diseases, diabetes, neurodegenerative disorders, and cancer. Additionally, cancer, like aging, is a complex disease that arises from the accumulation of various genetic and epigenetic alterations. Circadian clock dysregulation has recently been identified as an important risk factor for aging and cancer development. Natural compounds and herbal medicines have gained significant attention for their potential in preventing age-related diseases and inhibiting cancer progression. These compounds demonstrate antioxidant, anti-inflammatory, anti-proliferative, pro-apoptotic, anti-metastatic, and anti-angiogenic effects as well as circadian clock regulation. This review explores age-related diseases, cancers, and the potential of specific natural compounds in targeting the key features of these conditions.

Unraveling the therapeutic efficacy of resveratrol in Alzheimer's disease: an umbrella review of systematic evidence

CONTEXT

Resveratrol (RV), a natural compound found in grapes, berries, and peanuts, has been extensively studied for its potential in treating Alzheimer's disease (AD). RV has shown promise in inhibiting the formation of beta-amyloid plaques (Aβ) and neurofibrillary tangles (NFTs), protecting against neuronal damage and oxidative stress, reducing inflammation, promoting neuroprotection, and improving the function of the blood-brain barrier (BBB). However, conflicting results have been reported, necessitating a comprehensive umbrella review of systematic reviews to provide an unbiased conclusion on the therapeutic effectiveness of RV in AD.

OBJECTIVE

The objective of this study was to systematically synthesize and evaluate systematic and meta-analysis reviews investigating the role of RV in AD using data from both human and animal studies.

DATA SOURCES AND EXTRACTION

Of the 34 systematic and meta-analysis reviews examining the association between RV and AD that were collected, six were included in this study based on specific selection criteria. To identify pertinent studies, a comprehensive search was conducted in English-language peer-reviewed journals without any restrictions on the publication date until October 15, 2023. The search was carried out across multiple databases, including Embase, MEDLINE (PubMed), Cochrane Library, Web of Science, and Google Scholar, utilizing appropriate terms relevant to the specific research field. The AMSTAR-2 and ROBIS tools were also used to evaluate the quality and risk of bias of the included systematic reviews, respectively. Two researchers independently extracted and analyzed the data, resolving any discrepancies through consensus. Of note, the study adhered to the PRIOR checklist.

DATA ANALYSIS

This umbrella review presented robust evidence supporting the positive impacts of RV in AD, irrespective of the specific mechanisms involved. It indeed indicated that all six systematic and meta-analysis reviews unanimously concluded that the consumption of RV can be effective in the treatment of AD.

CONCLUSION

RV exhibits promising potential for benefiting individuals with AD through various mechanisms. It has been observed to enhance cognitive function, reduce Aβ accumulation, provide neuroprotection, protect the BBB, support mitochondrial function, facilitate synaptic plasticity, stabilize tau proteins, mitigate oxidative stress, and reduce neuroinflammation commonly associated with AD.

Insights into the Therapeutic and Pharmacological Properties of Resveratrol as a Nutraceutical Antioxidant Polyphenol in Health Promotion and Disease Prevention

Resveratrol (3, 5, 4'-trihydroxystilbene) is a polyphenolic derivative with herbal origin. It has attracted considerable attention in recent decades. Many studies have revealed the benefits of Resveratrol over several human disease models, including heart and neurological diseases, nephroprotective, immune regulation, antidiabetic, anti-obesity, age-related diseases, antiviral, and anticancer in experimental and clinical conditions. Recently, the antioxidant and anti-inflammatory activities of Resveratrol have been observed, and it has been shown that Resveratrol reduces inflammatory biomarkers, such as tissue degradation factor, cyclooxygenase 2, nitric oxide synthase, and interleukins. All of these activities appear to be dependent on its structural properties, such as the number and position of the hydroxyl group, which regulates oxidative stress, cell death, and inflammation. Resveratrol is well tolerated and safe even at higher pharmacological doses and desirably affects cardiovascular, neurological, and diabetic diseases. Consequently, it is plausible that Resveratrol can be regarded as a beneficial nutritional additive and a complementary drug, particularly for therapeutic applications. The present review provides an overview of currently available investigations on preventive and therapeutic characteristics and the main molecular mechanisms of Resveratrol and its potent derivatives in various diseases. Thus, this review would enhance knowledge and information about Resveratrol and encourage researchers worldwide to consider it as a pharmaceutical drug to struggle with future health crises against different human disorders.

Mediterranean Shrub Species as a Source of Biomolecules against Neurodegenerative Diseases

Neurodegenerative diseases are associated with oxidative stress, due to an imbalance in the oxidation-reduction reactions at the cellular level. Various treatments are available to treat these diseases, although they often do not cure them and have many adverse effects. Therefore, it is necessary to find complementary and/or alternative drugs that replace current treatments with fewer side effects. It has been demonstrated that natural products derived from plants, specifically phenolic compounds, have a great capacity to suppress oxidative stress and neutralize free radicals thus, they may be used as alternative alternative pharmacological treatments for pathological conditions associated with an increase in oxidative stress. The plant species that dominate the Mediterranean ecosystems are characterized by having a wide variety of phenolic compound content. Therefore, these species might be important sources of neuroprotective biomolecules. To evaluate this potential, 24 typical plant species of the Mediterranean ecosystems were selected, identifying the most important compounds present in them. This set of plant species provides a total of 403 different compounds. Of these compounds, 35.7% are phenolic acids and 55.6% are flavonoids. The most relevant of these compounds are gallic, vanillic, caffeic, chlorogenic, p-coumaric, and ferulic acids, apigenin, kaempferol, myricitrin, quercetin, isoquercetin, quercetrin, rutin, catechin and epicatechin, which are widely distributed among the analyzed plant species (in over 10 species) and which have been involved in the literature in the prevention of different neurodegenerative pathologies. It is also important to mention that three of these plant species, Pistacea lentiscus, Lavandula stoechas and Thymus vulgaris, have most of the described compounds with protective properties against neurodegenerative diseases. The present work shows that the plant species that dominate the studied geographic area can provide an important source of phenolic compounds for the pharmacological and biotechnological industry to prepare extracts or isolated compounds for therapy against neurodegenerative diseases.

Effect of resveratrol and combination of resveratrol and donepezil on the expression of microglial cells and astrocytes in Wistar albino rats of colchicine-induced Alzheimer's disease

Aim

The goal was to evaluate the effect of resveratrol (RS) and combination therapy of RS and donepezil (DPZ), on the numerical expression of microglial cells and astrocytes, in the frontal cortex, regions of the hippocampus in colchicine-induced Alzheimer's disease (AD) model.

Methods

The study involved male albino Wistar rats of three months, age and consisted of 6 groups, with six animals each. The immunohistochemical staining with mouse monoclonal anti-human CD 68 and mouse monoclonal anti-GFAP was performed to assess the number of microglial cells and astrocytes, respectively.

Results

AD group showed an increase in the number of microglia, and the numbers declined in the treatment groups, RS 10, RS 20, RS10/10 and DPZ + RS (p < 0.001). Astrocyte count was increased in the treatment groups in contrast to the AD group (p < 0.05). The DPZ + RS combination group revealed substantial elevation in the number of astrocytes and decreased microglial number among all the groups (p < 0.001).

Conclusion

RS administration has diminished the microglial number and elevated the number of astrocytes. The elevated reactive astrocytes have decreased the microglial population. However, the limitation of our study is utilizing the colchicine for the induction of neurodegeneration. Using the transgenic models of AD may give a better insight into the pathogenesis and effect of RS. Another limitation of this study is the administration of RS and DPZ through different routes. The prospects of this research include studying the probiotic nature of RS and the effect of RS in other neurodegenerative disorders.

Inhibition of Acetylcholinesterase and Amyloid-β Aggregation by Piceatannol and Analogs: Assessing In Vitro and In Vivo Impact on a Murine Model of Scopolamine-Induced Memory Impairment

Currently, no drug is effective in delaying the cognitive impairment of Alzheimer's disease, which ranks as one of the top 10 causes of death worldwide. Hydroxylated stilbenes are active compounds that exist in fruit and herbal plants. Piceatannol (PIC) and gnetol (GNT), which have one extra hydroxyl group in comparison to resveratrol (RSV), and rhapontigenin (RHA) and isorhapontigenin (isoRHA), which were metabolized from PIC in vivo and contain the same number of hydroxyl groups as RSV, were evaluated for their effects on Alzheimer's disease-associated factors in vitro and in animal experiments. Among the five hydroxylated stilbenes, PIC was shown to be the most active in DPPH radical scavenging and in inhibitory activities against acetylcholinesterase and amyloid-β peptide aggregations, with concentrations for half-maximal inhibitions of 40.2, 271.74, and 0.48 μM. The different interactions of the five hydroxylated stilbenes with acetylcholinesterase or amyloid-β were obtained by molecular docking. The scopolamine-induced ICR mice fed with PIC (50 mg/kg) showed an improved learning behavior in the passive avoidance tests and had significant differences (p < 0.05) compared with those in the control group. The RHA and isoRHA at 10 μM were proven to stimulate neurite outgrowths in the SH-SY5Y cell models. These results reveal that nutraceuticals or functional foods containing PIC have the potential for use in the treatment of neurodegenerative disorders.

The central administration of vitisin a, extracted from Vitis vinifera, improves cognitive function and related signaling pathways in a scopolamine-induced dementia model

Neurodegenerative disorders, such as Alzheimer's disease (AD), are characterized by cognitive function loss and progressive memory impairment. Vitis vinifera, which is consumed in the form of fruits and wines in various countries, contains several dietary stilbenoids that have beneficial effects on neuronal disorders related to cognitive impairment. However, few studies have investigated the hypothalamic effects of vitisin A, a resveratrol tetramer derived from V. vinifera stembark, on cognitive functions and related signaling pathways. In this study, we conducted in vitro, ex vivo, and in vivo experiments with multiple biochemical and molecular analyses to investigate its pharmaceutical effects on cognitive functions. Treatment with vitisin A increased cell viability and cell survival under H₂O₂-exposed conditions in a neuronal SH-SY5 cell line. Ex vivo experiments showed that vitisin A treatment restored the scopolamine-induced disruption of long-term potentiation (LTP) in the hippocampal CA3-CA1 synapse, indicating the restoration of synaptic mechanisms of learning and memory. Consistently, central administration of vitisin A ameliorated scopolamine-induced disruptions of cognitive and memory functions in C57BL/6 mice, as evidenced by Y-maze and passive avoidance tests. Further studies showed that vitisin A upregulates BDNF-CREB signaling in the hippocampus. Together, our findings suggest that vitisin A exhibits neuroprotective effects, at least partially, by upregulating BDNF-CREB signaling and LTP.

Neurotrophic fragments as therapeutic alternatives to ameliorate brain aging

Aging is a global phenomenon and a complex biological process of all living beings that introduces various changes. During this physiological process, the brain is the most affected organ due to changes in its structural and chemical functions, such as changes in plasticity and decrease in the number, diameter, length, and branching of dendrites and dendritic spines. Likewise, it presents a great reduction in volume resulting from the contraction of the gray matter. Consequently, aging can affect not only cognitive functions, including learning and memory, but also the quality of life of older people. As a result of the phenomena, various molecules with notable neuroprotective capacity have been proposed, which provide a therapeutic alternative for people under conditions of aging or some neurodegenerative diseases. It is important to indicate that in recent years the use of molecules with neurotrophic activity has shown interesting results when evaluated in in vivo models. This review aims to describe the neurotrophic potential of molecules such as resveratrol (3,5,4′-trihydroxystilbene), neurotrophins (brain-derived neurotrophic factor), and neurotrophic-type compounds such as the terminal carboxyl domain of the heavy chain of tetanus toxin, cerebrolysin, neuropeptide-12, and rapamycin. Most of these molecules have been evaluated by our research group. Studies suggest that these molecules exert an important therapeutic potential, restoring brain function in aging conditions or models of neurodegenerative diseases. Hence, our interest is in describing the current scientific evidence that supports the therapeutic potential of these molecules with active neurotrophic.

Hypoglycemic medicines in the treatment of Alzheimer's disease: Pathophysiological links between AD and glucose metabolism

Alzheimer's Disease (AD) is a global chronic disease in adults with beta-amyloid (Aβ) deposits and hyperphosphorylated tau protein as the pathologic characteristics. Although the exact etiology of AD is still not fully elucidated, aberrant metabolism including insulin signaling and mitochondria dysfunction plays an important role in the development of AD. Binding to insulin receptor substrates, insulin can transport through the blood-brain barrier (BBB), thus mediating insulin signaling pathways to regulate physiological functions. Impaired insulin signaling pathways, including PI3K/Akt/GSK3β and MAPK pathways, could cause damage to the brain in the pathogenesis of AD. Mitochondrial dysfunction and overexpression of TXNIP could also be causative links between AD and DM. Some antidiabetic medicines may have benefits in the treatment of AD. Metformin can be beneficial for cognition improvement in AD patients, although results from clinical trials were inconsistent. Exendin-4 may affect AD in animal models but there is a lack of clinical trials. Liraglutide and dulaglutide could also benefit AD patients in adequate clinical studies but not semaglutide. Dipeptidyl peptidase IV inhibitors (DPP4is) such as saxagliptin, vildagliptin, linagliptin, and sitagliptin could boost cognitive function in animal models. And SGLT2 inhibitors such as empagliflozin and dapagliflozin were also considerably protective against new-onset dementia in T2DM patients. Insulin therapy is a promising therapy but some studies indicated that it may increase the risk of AD. Herbal medicines are helpful for cognitive function and neuroprotection in the brain. For example, polyphenols, alkaloids, glycosides, and flavonoids have protective benefits in cognition function and glucose metabolism. Focusing on glucose metabolism, we summarized the pharmacological mechanism of hypoglycemic drugs and herbal medicines. New treatment approaches including antidiabetic synthesized drugs and herbal medicines would be provided to patients with AD. More clinical trials are needed to produce definite evidence for the effectiveness of hypoglycemic medications.

Resveratrol Analogues as Dual Inhibitors of Monoamine Oxidase B and Carbonic Anhydrase VII: A New Multi-Target Combination for Neurodegenerative Diseases?

Neurodegenerative diseases (NDs) are described as multifactorial and progressive syndromes with compromised cognitive and behavioral functions. The multi-target-directed ligand (MTDL) strategy is a promising paradigm in drug discovery, potentially leading to new opportunities to manage such complex diseases. Here, we studied the dual ability of a set of resveratrol (RSV) analogs to inhibit two important targets involved in neurodegeneration. The stilbenols 1−9 were tested as inhibitors of the human monoamine oxidases (MAOs) and carbonic anhydrases (CAs). The studied compounds displayed moderate to excellent in vitro enzyme inhibitory activity against both enzymes at micromolar/nanomolar concentrations. Among them, the best compound 4 displayed potent and selective inhibition against the MAO-B isoform (IC50 MAO-A 0.43 µM vs. IC50 MAO-B 0.01 µM) with respect to the parent compound resveratrol (IC50 MAO-A 13.5 µM vs. IC50 MAO-B > 100 µM). It also demonstrated a selective inhibition activity against hCA VII (KI 0.7 µM vs. KI 4.3 µM for RSV). To evaluate the plausible binding mode of 1−9 within the two enzymes, molecular docking and dynamics studies were performed, revealing specific and significant interactions in the active sites of both targets. The new compounds are of pharmacological interest in view of their considerably reduced toxicity previously observed, their physicochemical and pharmacokinetic profiles, and their dual inhibitory ability. Compound 4 is noteworthy as a promising lead in the development of MAO and CA inhibitors with therapeutic potential in neuroprotection.

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.

Amentoflavone Promotes Cellular Uptake and Degradation of Amyloid-Beta in Neuronal Cells

Deposition of fibrillar forms of amyloid β-protein (Aβ) is commonly found in patients with Alzheimer's disease (AD) associated with cognitive decline. Impaired clearance of Aβ species is thought to be a major cause of late-onset sporadic AD. Aβ secreted into the extracellular milieu can be cleared from the brain through multiple pathways, including cellular uptake in neuronal and non-neuronal cells. Recent studies have showed that the naturally-occurring polyphenol amentoflavone (AMF) exerts anti-amyloidogenic effects. However, its effects on metabolism and cellular clearance of Aβ remain to be tested. In the present study, we demonstrated that AMF significantly increased the cellular uptake of both Aβ_1-40 and Aβ_1-42, but not inverted Aβ_42-1 in mouse neuronal N2a cells. Though AMF promoted internalization of cytotoxic Aβ_1-42, it significantly reduced cell death in our assay condition. Our data further revealed that the internalized Aβ is translocated to lysosomes and undergoes enzymatic degradation. The saturable kinetic of Aβ uptake and our pharmacologic experiments showed the involvement of receptor-mediated endocytosis, in part, through the class A scavenger receptors as a possible mechanism of action of AMF. Taken together, our findings indicate that AMF can lower the levels of extracellular Aβ by increasing their cellular uptake and clearance, suggesting the therapeutic potential of AMF for the treatment of AD.

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.

The ameliorative effect of nanoselenium on histopathological and biochemical alterations induced by melamine toxicity on the brain of adult male albino rats

Melamine is a chemical substance used as a food adulterant because of its high nitrogen content; it is known to induce neurotoxicity, thereby adversely affecting the central nervous system. The biocompatibility, bioavailability, lower toxicity, and the large surface area of nanosized selenium relative to its other forms indicate that selenium nanoparticles (SeNPs) have a potential ameliorative effect against melamine-induced neurotoxicity. In this study, we tested this hypothesis using 40 adult male albino rats that were randomly assigned into four groups (n = 10 per group): group I rats served as the untreated negative controls and were fed with standard diet and distilled water; group II rats were orally treated with melamine (300 mg/kg body weight/d); group III rats orally received melamine (300 mg/kg body weight/d) and SeNPs (2 mg/kg body weight/d); and group IV rats received SeNPs only (2 mg/kg body weight/d) for 28 days. Blood and brain samples were collected from all rats and processed for biochemical, histopathological, and immunohistochemical investigations. SeNPs were encapsulated in starch as a natural stabilizer and a size-controlling agent (SeNP@starch). The prepared SeNPs were characterized using different techniques. Inductively coupled plasma-optical emission spectrometry (ICP-OES) indicated that the percentage of selenium loaded in starch was 1.888 %. Powder x-ray diffractometer (XRD) was used to investigate the crystalline structure of the Se-NP@starch, to be tubular and composed of amorphous starch as well as metallic selenium. Thermogravimetric analysis confirmed the thermal stability of the product and determined the interactions among the different components. Transmission electron microscope demonstrated the spherical shape of SeNPs and their dispersion into starch surface as well as evaluating their size in nanoscale (range 20-140 nm). Our results revealed that the melamine- exposed rats had significantly elevated in malondialdehyde levels, significantly reduced in total antioxidant capacity, down-regulated expression of the antioxidant related genes Nrf2 (nuclear factor erythroid 2-related factor 2) and GPx (glutathione peroxidase), as well as up-regulated expression of the apoptosis-related gene Bax (B-cell lymphoma 2-associated X protein), with down regulation of Bcl-2 (B-cell lymphoma 2). Histopathological examination exhibited several alterations in the cerebrum, cerebellum, and hippocampus of the treated rats compared with the controls. Neuronal degeneration, vacuolation of the neuropils, and pericellular and perivascular spaces were observed. In addition, the pyramidal and granular cell layers of the hippocampus and cerebellum, respectively, were found to have significantly reduced thickness. Furthermore, a significant decrease in the percentage area of the glial fibrillary acidic protein and a significant increase in the percentage area of caspase-3 were noted. On the other hand, co-treatment with SeNPs partially ameliorated these alterations. A significant reduction in malondialdehyde levels; a non- significant elevation in total antioxidant capacity; up-regulation, upregulation of Nrf2, GPx, and Bcl-2 and downregulation of Bax were recorded. Neuronal degeneration, vacuolation of neuropils, and pericellular spaces were reduced. The pyramidal and granular cell layers restored their normal thickness. The percentage area of the glial fibrillary acidic protein significantly increased, whereas that of caspase-3 significantly decreased. In conclusion, SeNPs have an ameliorative effect against melamine-induced neurotoxicity in albino rats.

Comparison of malondialdehyde levels and superoxide dismutase activity in resveratrol and resveratrol/donepezil combination treatment groups in Alzheimer's disease induced rat model

The aim of this study was to determine the malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in colchicine induced Alzheimer’s disease (AD), resveratrol (RS) treated and RS + donepezil (DPZ) treated rat models. The objective was to compare the MDA level and SOD activity among these rat models. The present study included 3 months old male albino Wistar rats, which were in-house bred and weighting about 220–250 g. The rats were divided into nine subgroups which included control, sham, AD induced, RS treated and DPZ treated groups in different doses and combinations. The lipid peroxidation product for MDA in the brain homogenate was measured by estimating the levels of thiobarbituric acid reactive substance. Estimation of SOD was done by the method of autoxidation of pyrogallol by Marklund and Marklund. There was a marked increase in the MDA levels in AD induced group in comparison to the control group (p < 0.05). The SOD activity was higher in the RS 10 and RS 20 treated groups in contrast to the AD group (p < 0.05). In DPZ + RS group, there was a substantial increase in the SOD activity (p < 0.05). It is also observed that the RS 20 treatment group showed higher SOD activity than the RS 10 group (p < 0.05). This study showed that, AD induced group had elevated levels of MDA, which indicates the poor oxidative stress–defence mechanism. The RS 10 and RS 20 groups showed higher SOD activity in comparison to the AD group, which indicated the improved oxidative stress–defence mechanism. The RS + DPZ group showed higher SOD activity, indicating a synergistic effect of DPZ and RS.

Nutraceuticals and their Derived Nano-formulations for the Prevention and Treatment of Alzheimer's disease

Alzheimer's disease is one of the common chronic neurological disorders and associated with cognitive dysfunction, depression and progressive dementia. Presence of β-amyloid or senile plaques, hyper-phosphorylated tau proteins, neurofibrillary tangle, oxidative-nitrative stress, mitochondrial dysfunction, endoplasmic reticulum stress, neuroinflammation and derailed neurotransmitter status are the hallmark of AD. Currently, donepezil, memantine, rivastigmine and galantamine are approved by the FDA for symptomatic management. It is well-known that these approved drugs only exert symptomatic relief and possess poor patient-compliance. Additionally, various published evidence shows the neuroprotective potential of various nutraceuticals via their antioxidant, anti-inflammatory and anti-apoptotic effects in the preclinical and clinical studies. These nutraceuticals possess a significant neuroprotective potential and hence, can be a future pharmacotherapeutic for the management and treatment of AD. However, nutraceutical suffers from certain major limitations such as poor solubility, low bioavailability, low stability, fast hepatic-metabolism and larger particle size. These pharmacokinetic attributes restrict their entry into the brain via the blood-brain barrier. Therefore, to over such issues, various nanoformulation of nutraceuticals was developed, that allows their effective delivery into brain owning to reduced particle size, increased lipophilicity increased bioavailability and avoidance of fast hepatic metabolism. Thus, in this review, we have discussed the etiology of AD, focused on the pharmacotherapeutics of nutraceuticals with preclinical and clinical evidence, discussed pharmaceutical limitation and regulatory aspects of nutraceuticals to ensure safety and efficacy. We further explored the latitude of various nanoformulation of nutraceuticals as a novel approach to overcome the existing pharmaceutical limitation and for effective delivery into the brain.

Neuroprotective Effect of Maternal Resveratrol Supplementation in a Rat Model of Neonatal Hypoxia-Ischemia

Neonatal hypoxia-ischemia (nHI) is a major cause of death or subsequent disabilities in infants. Hypoxia-ischemia causes brain lesions, which are induced by a strong reduction in oxygen and nutrient supply. Hypothermia is the only validated beneficial intervention, but not all newborns respond to it and today no pharmacological treatment exists. Among possible therapeutic agents to test, trans-resveratrol is an interesting candidate as it has been reported to exhibit neuroprotective effects in some neurodegenerative diseases. This experimental study aimed to investigate a possible neuroprotection by resveratrol in rat nHI, when administered to the pregnant rat female, at a nutritional dose. Several groups of pregnant female rats were studied in which resveratrol was added to drinking water either during the last week of pregnancy, the first week of lactation, or both. Then, 7-day old pups underwent a hypoxic-ischemic event. Pups were followed longitudinally, using both MRI and behavioral testing. Finally, a last group was studied in which breastfeeding females were supplemented 1 week with resveratrol just after the hypoxic-ischemic event of the pups (to test the curative rather than the preventive effect). To decipher the molecular mechanisms of this neuroprotection, RT-qPCR and Western blots were also performed on pup brain samples. Data clearly indicated that when pregnant and/or breastfeeding females were supplemented with resveratrol, hypoxic-ischemic offspring brain lesions were significantly reduced. Moreover, maternal resveratrol supplementation allowed to reverse sensorimotor and cognitive deficits caused by the insult. The best recoveries were observed when resveratrol was administered during both gestation and lactation (2 weeks before the hypoxic-ischemic event in pups). Furthermore, neuroprotection was also observed in the curative group, but only at the latest stages examined. Our hypothesis is that resveratrol, in addition to the well-known neuroprotective benefits via the sirtuin’s pathway (antioxidant properties, inhibition of apoptosis), has an impact on brain metabolism, and more specifically on the astrocyte-neuron lactate shuttle (ANLS) as suggested by RT-qPCR and Western blot data, that contributes to the neuroprotective effects.