Resveratrol, Metabolic Dysregulation, and Alzheimer's Disease: Considerations for Neurogenerative Disease

Development of a brain-targeted nano drug delivery system to enhance the treatment of neurodegenerative effects of resveratrol

As the aging population continues to increase, aging-related inflammation, oxidative stress, and neurodegenerative diseases have become serious global health threats. Resveratrol, a star molecule in natural polyphenols, has been widely reported to have physiological activities such as anti-aging, anti-inflammatory, antioxidant, and neuroprotection. However, its poor water solubility, rapid metabolism, low bioavailability and poor targeting ability, which limits its application. Accordingly, a brain-targeted resveratrol liposome (ANG-RES-LIP) was developed to solve these issues. Experimental results showed that ANG-RES-LIP has a uniform size distribution, good biocompatibility, and a drug encapsulation rate of over 90%. Furthermore, in vitro cell experiments showed that the modification of the targeting ligand ANG significantly increased the capability of RES to cross the BBB and neuronal uptake. Compared with free RES, ANG-RES-LIP demonstrated stronger antioxidant activity and the ability to rescue oxidatively damaged cells from apoptosis. Additionally, ANG-RES-LIP showed the ability to repair damaged neuronal mitochondrial membrane potential. In vivo experiments further demonstrated that ANG-RES-LIP improved cognitive function by reducing oxidative stress and inflammation levels in the brains of aging model mice, repairing damaged neurons and glial cells, and increasing brain-derived neurotrophic factor. In summary, this study not only provides a new method for further development and application of resveratrol but also a promising strategy for preventing and treating age-related neurodegenerative diseases.

Resveratrol for inflammatory bowel disease in preclinical studies: a systematic review and meta-analysis

Background: Inflammatory bowel disease (IBD) is a chronic condition that can be managed with treatment, but it is challenging to get IBD cured. Resveratrol, a non-flavonoid polyphenolic organic compound derived from various plants, has a potential effect on IBD. The current research was set out to investigate the therapeutic effects of resveratrol on animal models of IBD. Methods: A comprehensive search of PubMed, Embase, Web of Science, and Chinese databases was performed. The literature search process was completed independently by two people and reviewed by a third person. The risk of bias in the included literature was assessed using the Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Stroke (CAMARADES) 10-point quality checklist. The meta-analysis utilized Review Manager 5.4 software to evaluate the efficacy of resveratrol, with histopathological index as the primary outcome measure. Subgroup analysis was conducted based on this indicator. Additionally, meta-analyses were carried out on different outcomes reported in the literature, including final disease activity index, final body weight change, colon length, splenic index, and inflammatory factors. Results: After conducting a thorough literature search and selection process, a total of 28 studies were ultimately included in the analysis. It was found that over half of the selected studies had more than five items with low risk of bias in the bias risk assessment. Relevant datas from included literature indicated that the histopathological index of the resveratrol group was significantly lower than that of the control group (WMD = -2.58 [-3.29, -1.87]). Subgroup analysis revealed that higher doses of resveratrol (>80 mg/kg) had a better efficacy (WMD = -3.47 [-4.97, -1.98]). Furthermore, The data summary and quantitative analysis results of SI and colon length also showed that resveratrol was effective in alleviating intestinal mucosal pathological injury of IBD. In terms of biochemical indicators, the summary analysis revealed that resveratrol affected interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), interferon-γ (IFN-γ), malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), and prostaglandin E2 (PGE2) significantly. These effects may be attributed to the mechanism of resveratrol in regulating immune response and inhibiting oxidative stress. Conclusion: This review suggests that resveratrol demonstrated a notable therapeutic impact in preclinical models of IBD, particularly at doses exceeding 80 mg/kg. This efficacy is attributed to the protective mechanisms targeting the intestinal mucosa involved in the pathogenesis of IBD through various pathways. As a result, resveratrol holds promising prospects for potential clinical use in the future.

Resveratrol Reduces Neuroinflammation and Hippocampal Microglia Activation and Protects Against Impairment of Memory and Anxiety-Like Behavior in Experimental Cerebral Palsy

Cerebral palsy (CP) is a neurodevelopmental disorder characterized by motor and postural impairments. However, early brain injury can promote deleterious effects on the hippocampus, impairing memory. This study aims to investigate the effects of resveratrol treatment on memory, anxiety-like behavior, and neuroinflammation markers in rats with CP. Male Wistar rats were subjected to perinatal anoxia (P0-P1) and sensory-motor restriction (P2-P28). They were treated with resveratrol (10 mg/kg, 0.1 ml/100 g) or saline from P3-P21, being divided into four experimental groups: CS (n = 15), CR (n = 15), CPS (n = 15), and CPR (n = 15). They were evaluated in the tests of novel object recognition (NORT), T-Maze, Light-Dark Box (LDB), and Elevated Plus Maze (EPM). Compared to the CS group, the CPS group has demonstrated a reduced discrimination index on the NORT (p < 0.0001) and alternation on the T-Maze (p < 0.01). In addition, the CPS group showed an increase in permanence time on the dark side in LDB (p < 0.0001) and on the close arms of the EPM (p < 0.001). The CPR group demonstrated an increase in the object discrimination index (p < 0.001), on the alternation (p < 0.001), on the permanence time on the light side (p < 0.0001), and on the open arms (p < 0.001). The CPR group showed a reduction in gene expression of IL-6 (p = 0.0175) and TNF-α (p = 0.0007) and an increase in Creb-1 levels (p = 0.0020). The CPS group showed an increase in the activated microglia and a reduction in cell proliferation in the hippocampus, while CPR animals showed a reduction of activated microglia and an increase in cell proliferation. These results demonstrate promising effects of resveratrol in cerebral palsy behavior impairment through reduced neuroinflammation in the hippocampus.

Epigenetic Changes in Alzheimer's Disease: DNA Methylation and Histone Modification

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by progressive cognitive decline and memory loss, imposing a significant burden on affected individuals and their families. Despite the recent promising progress in therapeutic approaches, more needs to be done to understand the intricate molecular mechanisms underlying the development and progression of AD. Growing evidence points to epigenetic changes as playing a pivotal role in the pathogenesis of the disease. The dynamic interplay between genetic and environmental factors influences the epigenetic landscape in AD, altering gene expression patterns associated with key pathological events associated with disease pathogenesis. To this end, epigenetic alterations not only impact the expression of genes implicated in AD pathogenesis but also contribute to the dysregulation of crucial cellular processes, including synaptic plasticity, neuroinflammation, and oxidative stress. Understanding the complex epigenetic mechanisms in AD provides new avenues for therapeutic interventions. This review comprehensively examines the role of DNA methylation and histone modifications in the context of AD. It aims to contribute to a deeper understanding of AD pathogenesis and facilitate the development of targeted therapeutic strategies.

Molecular interplay between phytoconstituents of Ficus Racemosa and neurodegenerative diseases

Neurodegenerative diseases (NDs) are a significant global health concern, primarily affecting middle and older populations. Recently, there has been growing interest in herbal therapeutics as a potential approach to address diverse neuropathological conditions. Despite the widespread prevalence of NDs, limited phytochemical has been reported for their promising therapeutic potential with distinct underlying mechanisms. Additionally, the intricate molecular pathways influenced by herbal phytoconstituents, particularly in neurodegenerative disorders, are also not well documented. This report explores the phytoconstituents of Ficus racemosa (F. racemosa), an unfamiliar plant of the Moraceae family, for their potential interactions with pathological pathways of NDs. The influential phytoconstituents of F. racemosa, including polyphenols, glycosides, terpenoids, and furocoumarin, have been reported for targeting diverse pathological states. We proposed the most convincing molecular interplay between leading phytoconstituents and detrimental signalling cascades. However, extensive research is required to thoroughly understand the phytochemical persuaded intricate molecular pathway. The comprehensive evidence strongly suggests that F. racemosa and its natural compounds could be valuable in treating NDs. This points towards an exciting path for future research and the development of potential treatments based on a molecular level.

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.

Dietary Polyphenols against Oxidative Stress in Head and Neck Cancer: What's New, What's Next

Head and neck cancers (HNC) are a worldwide health problem, accounting for over 5% of all types of cancers. Their varied nature makes it sometimes difficult to find clear explanations for the molecular mechanisms that underline their onset and development. While chemio- and radiotherapy are clearly not to be dismissed, we cannot undervalue the effect that polyphenols - especially dietary polyphenols - can have in helping us to cope with this medical emergency. By influencing several different proteins involved in numerous different metabolic pathways, polyphenols can have a broad spectrum of biological action and can hopefully act synergistically to tackle down head and neck cancer. Moreover, being natural molecules, polyphenols does not present any side effects and can even enhance drugs efficacy, making our clinical therapy against head and neck cancer more and more effective. Certainly, oxidative stress plays an important role, altering several molecular pathways, lowering the body's defenses, and ultimately helping to create a microenvironment conducive to the appearance and development of the tumor. In this regard, the regular and constant intake of foods rich in polyphenols can help counteract the onset of oxidative stress, improving the health of the general population. In this review, we highlight the role of polyphenols in managing oxidative stress, with such positive effects that they can be considered new tools to use in our anti-head and neck cancer strategy.

Parthenolide alleviates cognitive dysfunction and neurotoxicity via regulation of AMPK/GSK3β(Ser9)/Nrf2 signaling pathway

Alzheimer's disease (AD) stands as the predominant age-related neurodegenerative disorder, for which efficacious treatment remains elusive. An auspicious avenue for this disease lies in natural compounds sourced from tranditional medicine and plant origins. Parthenolide (PTN) is a natural product with multiple biological functionsand. Recent investigations have illuminated PTN's protective properties against neurological maladies; however, its potential therapeutic role against AD remains uncharted. This study aims to explore the role of PTN in treating AD. Our in vitro findings underscore PTN's bioactivity, as evidenced by its capacity to curtail apoptosis, reduce reactive oxygen species (ROS) production, and restore mitochondrial membrane potential in PC12 cells. Moreover, PTN treatment demonstrates a capacity to ameliorate deficits in spatial learning and memory in the 3 ×Tg-AD murine model. Notably, PTN's therapeutic efficacy surpasses that of a clinical agent, donepezil. Mechanistically, PTN's neuroprotective effects stem from its adept regulation of the AMPK/GSK3β(ser9)/Nrf2 signaling pathway and protection on neuronal cells from ROS-related apoptosis. Although the molecular target and the pre-clinical evaluations of PTN need to be further explored, this study indicates PTN as a potential agent or lead compound for the drug development against AD.

Mitochondrial Targeting against Alzheimer's Disease: Lessons from Hibernation

Alzheimer's disease (AD) is the most common cause of dementia worldwide and yet remains without effective therapy. Amongst the many proposed causes of AD, the mitochondrial cascade hypothesis is gaining attention. Accumulating evidence shows that mitochondrial dysfunction is a driving force behind synaptic dysfunction and cognitive decline in AD patients. However, therapies targeting the mitochondria in AD have proven unsuccessful so far, and out-of-the-box options, such as hibernation-derived mitochondrial mechanisms, may provide valuable new insights. Hibernators uniquely and rapidly alternate between suppression and re-activation of the mitochondria while maintaining a sufficient energy supply and without acquiring ROS damage. Here, we briefly give an overview of mitochondrial dysfunction in AD, how it affects synaptic function, and why mitochondrial targeting in AD has remained unsuccessful so far. We then discuss mitochondria in hibernation and daily torpor in mice, covering current advancements in hibernation-derived mitochondrial targeting strategies. We conclude with new ideas on how hibernation-derived dual mitochondrial targeting of both the ATP and ROS pathways may boost mitochondrial health and induce local synaptic protein translation to increase synaptic function and plasticity. Further exploration of these mechanisms may provide more effective treatment options for AD in the future.

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

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

Aluminum exposure induces central nervous system impairment via activating NLRP3-medicated pyroptosis pathway

PURPOSE

Aluminum is an environmental toxicant whose long-term exposure is closely associated with nervous system impairment. This study mainly investigated neurological impairment induced by subchronic aluminum exposure via activating NLRP3-medicated pyroptosis pathway.

METHODS

In vivo, Kunming mice were exposed to AlCl3 (30.3 mg/kg, 101 mg/kg and 303 mg/kg) via drinking water for 3 months, and administered with Rsv (100 mg/kg) by gavage for 1 month. Cognitive impairment was assessed by Morris water maze test, and pathological injury was detected via H&E staining. BBB integrity, pyroptosis and neuroinflammation were evaluated through western blotting and immunofluorescence methods. In vitro, BV2 microglia was treated with AlCl3 (0.5 mM, 1 mM and 2 mM) to sensitize pyroptosis pathway. The protein interaction was verified by co-immunoprecipitation, and neuronal damage was estimated via a conditioned medium co-culture system with BV2 and TH22 cells.

RESULTS

Our results showed that AlCl3 induced mice memory disorder, BBB destruction, and pathological injury. Besides, aluminum caused glial activation, sensitized DDX3X-NLRP3 pyroptosis pathway, released cytokines IL-1β and IL-18, initiating neuroinflammation. BV2 microglia treated with AlCl3 emerged hyperactivation and pyroptotic death, and Ddx3x knockdown inhibited pyroptosis signaling pathway. DDX3X acted as a live-or-die checkpoint in stressed cells by regulating NLRP3 inflammasome and G3BP1 stress granules. Furthermore, aluminum-activated microglia had an adverse effect on co-cultured neurons and destroyed nervous system homeostasis.

CONCLUSION

Aluminum exposure could induce pyroptosis and neurotoxicity. DDX3X determined live or die via selectively regulating pro-survival stress granules or pro-death NLRP3 inflammasome. Excessive activation of microglia might damage neurons and aggravate nerve injury.

Targeting impaired nutrient sensing via the sirtuin pathway with novel compounds to prevent or treat dementia: A systematic review

BACKGROUND

Dementia is prevalent in aged populations and is associated with disability and distress for those affected. Therapeutic benefits of drugs targeting dementia are small. Impaired nutrient sensing pathways have been implicated in the pathogenesis of dementia and may offer a novel treatment target.

AIMS

This systematic review collated evidence for novel therapeutic compounds that modify nutrient sensing pathways, particularly the sirtuin pathway, in preventing cognitive decline or improving cognition in normal ageing, mild cognitive impairment (MCI), and dementia.

METHODS

PubMed, Embase and Web of Science databases were searched using key search terms. Articles were screened using Covidence systematic review software. The risk of bias was assessed using the Systematic Review Center for Laboratory animal Experimentation (SYRCLE)'s risk of bias tool for animal studies and Cochrane Risk of Bias tool v 2.0 for human studies.

RESULTS

Out of 3841 articles, 68 were included describing 38 different novel therapeutic compounds that modulate the nutrient sensing pathway via the sirtuin pathway. In animal models (58 studies), all investigated novel therapeutic compounds showed cognitive benefits. Ten studies were human intervention trials targeting normal ageing (1 study) and dementia populations (9 studies). Direct sirtuin (silent mating type information regulation 2 homolog) 1 (SIRT1) activators Resveratrol and Nicotinamide derivatives improved cognitive outcomes among human subjects with normal cognition and MCI.

CONCLUSION

Animal studies support that modulation of the sirtuin pathway has the potential to improve cognitive outcomes. Overall, there is a clear lack of translation from animal models to human populations.

Therapeutic Strategies Aimed at Improving Neuroplasticity in Alzheimer Disease

Alzheimer disease (AD) is the most prevalent form of dementia among elderly people. Owing to its varied and multicausal etiopathology, intervention strategies have been highly diverse. Despite ongoing advances in the field, efficient therapies to mitigate AD symptoms or delay their progression are still of limited scope. Neuroplasticity, in broad terms the ability of the brain to modify its structure in response to external stimulation or damage, has received growing attention as a possible therapeutic target, since the disruption of plastic mechanisms in the brain appear to correlate with various forms of cognitive impairment present in AD patients. Several pre-clinical and clinical studies have attempted to enhance neuroplasticity via different mechanisms, for example, regulating glucose or lipid metabolism, targeting the activity of neurotransmitter systems, or addressing neuroinflammation. In this review, we first describe several structural and functional aspects of neuroplasticity. We then focus on the current status of pharmacological approaches to AD stemming from clinical trials targeting neuroplastic mechanisms in AD patients. This is followed by an analysis of analogous pharmacological interventions in animal models, according to their mechanisms of action.

Interplay between Systemic Glycemia and Neuroprotective Activity of Resveratrol in Modulating Astrocyte SIRT1 Response to Neuroinflammation

The flow of substances between the blood and the central nervous system is precisely regulated by the blood-brain barrier (BBB). Its disruption due to unbalanced blood glucose levels (hyper- and hypoglycemia) occurring in metabolic disorders, such as type 2 diabetes, can lead to neuroinflammation, and increase the risk of developing neurodegenerative diseases. One of the most studied natural anti-diabetic, anti-inflammatory, and neuroprotective compounds is resveratrol (RSV). It activates sirtuin 1 (SIRT1), a key metabolism regulator dependent on cell energy status. The aim of this study was to assess the astrocyte SIRT1 response to neuroinflammation and subsequent RSV treatment, depending on systemic glycemia. For this purpose, we used an optimized in vitro model of the BBB consisting of endothelial cells and astrocytes, representing microvascular and brain compartments (MC and BC), in different glycemic backgrounds. Astrocyte-secreted SIRT1 reached the highest concentration in hypo-, the lowest in normo-, and the lowest in hyperglycemic backgrounds. Lipopolysaccharide (LPS)-induced neuroinflammation caused a substantial decrease in SIRT1 in all glycemic backgrounds, as observed earliest in hyperglycemia. RSV partially counterbalanced the effect of LPS on SIRT1 secretion, most remarkably in normoglycemia. Our results suggest that abnormal glycemic states have a worse prognosis for RSV-therapy effectiveness compared to normoglycemia.

The Role of Heme and Copper in Alzheimer's Disease and Type 2 Diabetes Mellitus

Beyond the well-explored proposition of protein aggregation or amyloidosis as the central event in amyloidogenic diseases like Alzheimer's Disease (AD), and Type 2 Diabetes Mellitus (T2Dm); there are alternative hypotheses, now becoming increasingly evident, which suggest that the small biomolecules like redox noninnocent metals (Fe, Cu, Zn, etc.) and cofactors (Heme) have a definite influence in the onset and extent of such degenerative maladies. Dyshomeostasis of these components remains as one of the common features in both AD and T2Dm etiology. Recent advances in this course reveal that the metal/cofactor-peptide interactions and covalent binding can alarmingly enhance and modify the toxic reactivities, oxidize vital biomolecules, significantly contribute to the oxidative stress leading to cell apoptosis, and may precede the amyloid fibrils formation by altering their native folds. This perspective highlights this aspect of amyloidogenic pathology which revolves around the impact of the metals and cofactors in the pathogenic courses of AD and T2Dm including the active site environments, altered reactivities, and the probable mechanisms involving some highly reactive intermediates as well. It also discusses some in vitro metal chelation or heme sequestration strategies which might serve as a possible remedy. These findings might open up a new paradigm in our conventional understanding of amyloidogenic diseases. Moreover, the interaction of the active sites with small molecules elucidates potential biochemical reactivities that can inspire designing of drug candidates for such pathologies.

Mechanistic insight into gel formation of co-amorphous resveratrol and piperine during dissolution process

Different from previous co-amorphous systems, co-amorphous resveratrol and piperine (namely RES-PIP CM) showed much lower dissolution in comparison to the original two crystalline drugs owing to its gel formation during dissolution. The purpose of this study is to investigate the mechanism of gel formation and seek strategies to eliminate such gelation. It was found that the dissolution performance of RES-PIP CM and the properties of formed gels were significantly affected by the medium temperature and stoichiometric ratio of components. Multiple characterization results confirmed that the gelation process underwent the decrease of T_g caused by water plasticization, and then entered into its supercooled liquid state with high viscosity, accompanied by self-assembly of molecules. Furthermore, the study answered the question that whether such gelation of RES-PIP CM could be eliminated by porous carrier materials. The materials, mesoporous silica (MES) and attapulgite (ATT), provided barrier and well separation between molecules and particles of RES-PIP CM by the pore steric hindrance, and impeded the self-assembly and aggregation, hence achieving the degelation and dissolution improvement. The present study highlights the importance of recognizing gelation potential of some co-amorphous formulations, and provides an effective strategy to eliminate gelation in developing high quality co-amorphous drug products.

Resveratrol improves diabetes-induced cognitive dysfunction in part through the miR-146a-5p/TXNIP axis

Resveratrol (RSV) has been shown to have a neuroprotective effect in various central nervous system disorders, although the role of RSV in diabetes-induced cognitive dysfunction is still not fully elucidated. Here, we investigated whether RSV improved diabetes-related cognitive dysfunction in vivo and in vitro. We induced a rat diabetic model with a high-fat and high-sucrose diet followed by intraperitoneal injection of streptozotocin and a diabetic neuron cell model by stimulation with high levels of glucose. We observed that RSV improved impairment in spatial learning and memory in the Morris water maze test (MWM) and novel object recognition test (ORT) in diabetic rats. RSV reversed the reduced miR-146a-5p and upregulated thioredoxin-interacting protein (TXNIP) and inhibited the diabetes-induced increase in interleukin (IL)-1β and tumor necrosis factor (TNF)-α levels in vivo and in vitro. RSV also inhibited diabetes-induced endoplasmic reticulum stress (ESR) by reducing ESR-related protein expression in vivo and in vitro. Moreover, inhibition of miR-146a-5p partially abolished the protective effects of RSV in HG-treated primary neurons. Additionally, we used starBase to predict that miR-146a-5p interacts with TXNIP, which we then verified using a luciferase reporter gene assay. We further observed that miR-146a-5p regulates the mRNA and protein expression of TXNIP in vitro, indicating that the miR-146a-5p/TXNIP axis is involved in the regulation of cognitive dysfunction in a rat diabetic model. Collectively, these results demonstrate that RSV plays a neuroprotective role in diabetes-associated cognitive dysfunction at least in part through regulation of the miR-146a-5p/TXNIP axis.

Oxidative Stress and Natural Antioxidants: Back and Forth in the Neurological Mechanisms of Alzheimer's Disease

Alzheimer's disease (AD) is characterized by the progressive degeneration of neuronal cells. With the increase in aged population, there is a prevalence of irreversible neurodegenerative changes, causing a significant mental, social, and economic burden globally. The factors contributing to AD are multidimensional, highly complex, and not completely understood. However, it is widely known that aging, neuroinflammation, and excessive production of reactive oxygen species (ROS), along with other free radicals, substantially contribute to oxidative stress and cell death, which are inextricably linked. While oxidative stress is undeniably important in AD, limiting free radicals and ROS levels is an intriguing and potential strategy for deferring the process of neurodegeneration and alleviating associated symptoms. Therapeutic compounds from natural sources have recently become increasingly accepted and have been effectively studied for AD treatment. These phytocompounds are widely available and a multitude of holistic therapeutic efficiencies for treating AD owing to their antioxidant, anti-inflammatory, and biological activities. Some of these compounds also function by stimulating cholinergic neurotransmission, facilitating the suppression of beta-site amyloid precursor protein-cleaving enzyme 1, α-synuclein, and monoamine oxidase proteins, and deterring the occurrence of AD. Additionally, various phenolic, flavonoid, and terpenoid phytocompounds have been extensively described as potential palliative agents for AD progression. Preclinical studies have shown their involvement in modulating the cellular redox balance and minimizing ROS formation, displaying them as antioxidant agents with neuroprotective abilities. This review emphasizes the mechanistic role of natural products in the treatment of AD and discusses the various pathological hypotheses proposed for AD.

Resveratrol-Mediated Regulation of Mitochondria Biogenesis-associated Pathways in Neurodegenerative Diseases: Molecular Insights and Potential Therapeutic Applications

Neurodegenerative disorders include different neurological conditions that affect nerve cells, causing the progressive loss of their functions and ultimately leading to loss of mobility, coordination, and mental functioning. The molecular mechanisms underpinning neurodegenerative disease pathogenesis are still unclear. Nonetheless, there is experimental evidence to demonstrate that the perturbation of mitochondrial function and dynamics play an essential role. In this context, mitochondrial biogenesis, the growth, and division of preexisting mitochondria, by controlling mitochondria number, plays a vital role in maintaining proper mitochondrial mass and function, thus ensuring efficient synaptic activity and brain function. Mitochondrial biogenesis is tightly associated with the control of cell division and variations in energy demand in response to extracellular stimuli; therefore, it may represent a promising therapeutic target for developing new curative approaches to prevent or counteract neurodegenerative disorders. Accordingly, several inducers of mitochondrial biogenesis have been proposed as pharmacological targets for treating diverse central nervous system conditions. The naturally occurring polyphenol resveratrol has been shown to promote mitochondrial biogenesis in various tissues, including the nervous tissue, and an ever-growing number of studies highlight its neurotherapeutic potential. Besides preventing cognitive impairment and neurodegeneration through its antioxidant and anti-inflammatory properties, resveratrol has been shown to be able to enhance mitochondria biogenesis by acting on its main effectors, including PGC-1α, SIRT1, AMPK, ERRs, TERT, TFAM, NRF-1 and NRF-2. This review aims to present and discuss the current findings concerning the impact of resveratrol on the machinery and main effectors modulating mitochondrial biogenesis in the context of neurodegenerative diseases.

Evidence of Clinical Efficacy and Pharmacological Mechanisms of Resveratrol in the Treatment of Alzheimer's Disease

BACKGROUND

To evaluate the efficacy and pharmacological mechanisms of resveratrol in Alzheimer's disease (AD) patients.

METHODS

We conducted a thorough exploration of existing randomized controlled trials concerning the treatment of Alzheimer's disease patients using resveratrol, utilizing accessible open databases. Quantitative variables were represented as a standardized mean difference (SMD), accompanied by a 95% confidence interval (CI). Additionally, we examined the potential targets and plausible pathways associated with the impact of resveratrol on Alzheimer's disease using network pharmacology techniques.

RESULTS

Our meta-analysis comprised five trials involving 271 AD patients, of whom 139 received resveratrol treatment and 132 received placebo treatment. Compared with placebo therapy, resveratrol treatment resulted in a significant improvement in Alzheimer's Disease Cooperative Study- Activities of Daily Living (ADAS-ADL) scores (SMD=0.51; 95% CI, 0.24 to 0.78) and cerebrospinal fluid (CSF) Aβ40 (SMD=0.84; 95% CI, 0.21 to 1.47) and plasma Aβ40 levels (SMD=0.43; 95% CI, 0.07 to 0.79). However, the improvement in the resveratrol-treated group compared with the placebo treatment group on the Mini-Mental State Examination (MMSE) score, CSF Aβ42 and plasma Aβ42 levels, and brain volume was not significant. There were no noteworthy statistical variances in the occurrence of adverse effects noted between the two groups. The outcomes of network pharmacology divulged that the principal enriched interaction pathway between resveratrol and Alzheimer's disease is primarily concentrated within the PI3K signaling pathways. Resveratrol's potential key targets for the treatment of AD include MAKP1, HRAS, EGFR, and MAPK2K1.

CONCLUSION

While having a high safety profile, resveratrol has efficacy in AD patients to a certain extent, and more data are required to validate the efficacy of resveratrol for the treatment of AD in the future. Suppression of the PI3K signaling pathways could hold significant importance in the treatment of AD patients using resveratrol.

CK2 and protein kinases of the CK1 superfamily as targets for neurodegenerative disorders

Casein kinases are involved in a variety of signaling pathways, and also in inflammation, cancer, and neurological diseases. Therefore, they are regarded as potential therapeutic targets for drug design. Recent studies have highlighted the importance of the casein kinase 1 superfamily as well as protein kinase CK2 in the development of several neurodegenerative pathologies, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis. CK1 kinases and their closely related tau tubulin kinases as well as CK2 are found to be overexpressed in the mammalian brain. Numerous substrates have been detected which play crucial roles in neuronal and synaptic network functions and activities. The development of new substances for the treatment of these pathologies is in high demand. The impact of these kinases in the progress of neurodegenerative disorders, their bona fide substrates, and numerous natural and synthetic compounds which are able to inhibit CK1, TTBK, and CK2 are discussed in this review.

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.

Regulation of mitochondrial dysfunction induced cell apoptosis is a potential therapeutic strategy for herbal medicine to treat neurodegenerative diseases

Neurodegenerative disease is a progressive neurodegeneration caused by genetic and environmental factors. Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD) are the three most common neurodegenerative diseases clinically. Unfortunately, the incidence of neurodegenerative diseases is increasing year by year. However, the current available drugs have poor efficacy and large side effects, which brings a great burden to the patients and the society. Increasing evidence suggests that occurrence and development of the neurodegenerative diseases is closely related to the mitochondrial dysfunction, which can affect mitochondrial biogenesis, mitochondrial dynamics, as well as mitochondrial mitophagy. Through the disruption of mitochondrial homeostasis, nerve cells undergo varying degrees of apoptosis. Interestingly, it has been shown in recent years that the natural agents derived from herbal medicines are beneficial for prevention/treatment of neurodegenerative diseases via regulation of mitochondrial dysfunction. Therefore, in this review, we will focus on the potential therapeutic agents from herbal medicines for treating neurodegenerative diseases via suppressing apoptosis through regulation of mitochondrial dysfunction, in order to provide a foundation for the development of more candidate drugs for neurodegenerative diseases from herbal medicine.

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.

Signal pathways in the treatment of Alzheimer's disease with traditional Chinese medicine

AIM OF THE REVIEW

This study aimed to reveal the classical signal pathways and important potential targets of traditional Chinese medicine (TCM) for treating Alzheimer's disease (AD), and provide support for further investigation on TCM and its active ingredients.

MATERIALS AND METHODS

Literature survey was conducted using PubMed, Web of Science, Google Scholar, CNKI, and other databases, with "Alzheimer's disease," "traditional Chinese medicine," "medicinal herb," "Chinese herb," and "natural plant" as the primary keywords.

RESULTS

TCM could modulate signal pathways related to AD pathological progression, including NF-κB, Nrf2, JAK/STAT, ubiquitin-proteasome pathway, autophagy-lysosome pathway-related AMPK/mTOR, GSK-3/mTOR, and PI3K/Akt/mTOR, as well as SIRT1 and PPARα pathway. It could regulate crosstalk between pathways through a multitarget, thus maintaining chronic inflammatory interaction balance, inhibiting oxidative stress damage, regulating ubiquitin-proteasome system function, modulating autophagy, and eventually improving cognitive impairment in patients with AD.

CONCLUSION

TCM could be multilevel, multitargeted, and multifaceted to prevent and treat AD. In-depth research on the prevention and treatment of AD with TCM could provide new ideas for exploring the pathogenesis of AD and developing new anti-AD drugs.

Melatonin-related signaling pathways and their regulatory effects in aging organisms

Melatonin is a tryptophan-derived ancestral molecule evolved in bacteria. According to the endosymbiotic theory, eukaryotic cells received mitochondria, plastids, and other organelles from bacteria by internalization. After the endosymbiosis, bacteria evolved into organelles and retained their ability of producing melatonin. Melatonin is a small, evolutionarily conserved indole with multiple receptor-mediated, receptor-dependent, and independent actions. Melatonin's initial function was likely a radical scavenger in bacteria that's why there was high intensity of free radicals on primitive atmosphere in the ancient times, and hormetic functions of melatonin, which are effecting through the level of gene expression via prooxidant and antioxidant redox pathways, are developed in throughout the eukaryotic evolution. In the earlier stages of life, endosymbiotic events between mitochondria and other downstream organelles continue with mutual benefits. However, this interaction gradually deteriorates as a result of the imperfection of both mitochondrial and extramitochondrial endosymbiotic crosstalk with the advancing age of eukaryotic organisms. Throughout the aging process melatonin levels tend to reduce and as a manifestation of this, many symptoms in organisms' homeostasis, such as deterioration in adjustment of cellular clocks, are commonly seen. In addition, due to deterioration in mitochondrial integrity and functions, immunity decreases, and lower levels of melatonin renders older individuals to be more susceptible to impaired redox modulation and age-related diseases. Our aim in this paper is to focus on the several redox modulation mechanisms in which melatonin signaling has a central role, to discuss melatonin's gerontological aspects and to provide new research ideas with researchers.

Recent advance on carbamate-based cholinesterase inhibitors as potential multifunctional agents against Alzheimer's disease

Alzheimer's disease (AD), as the fourth leading cause of death among the elderly worldwide, has brought enormous challenge to the society. Due to its extremely complex pathogeneses, the development of multi-target directed ligands (MTDLs) becomes the major strategy for combating AD. Carbamate moiety, as an essential building block in the development of MTDLs, exhibits structural similarity to neurotransmitter acetylcholine (ACh) and has piqued extensive attention in discovering multifunctional cholinesterase inhibitors. To date, numerous preclinical studies demonstrate that carbamate-based cholinesterase inhibitors can prominently increase the level of ACh and improve cognition impairments and behavioral deficits, providing a privileged strategy for the treatment of AD. Based on the recent research focus on the novel cholinesterase inhibitors with multiple biofunctions, this review aims at summarizing and discussing the most recent studies excavating the potential carbamate-based MTDLs with cholinesterase inhibition efficacy, to accelerate the pace of pleiotropic cholinesterase inhibitors for coping AD.

Neuroprotective Potency of Neolignans in Magnolia officinalis Cortex Against Brain Disorders

In recent years, neurological diseases including Alzheimer’s disease, Parkinson’s disease and stroke are one of the main causes of death in the world. At the same time, the incidence of psychiatric disorders including depression and anxiety has been increasing. Accumulating elderly and stressed people suffer from these brain disorders, which is undoubtedly a huge burden on the modern aging society. Neolignans, the main active ingredients in Magnolia officinalis cortex, were reported to have neuroprotective effects. In addition, the key bioactive ingredients of neolignans, magnolol (1) and honokiol (2), were proved to prevent and treat neurological diseases and psychiatric disorders by protecting nerve cells and brain microvascular endothelial cells (BMECs). Furthermore, neolignans played a role in protecting nerve cells via regulation of neuronal function, suppression of neurotoxicity, etc. This review summarizes the neuroprotective effect, primary mechanisms of the leading neolignans and provides new prospects for the treatment of brain disorders in the future.

The Role of Resveratrol in Mild Cognitive Impairment and Alzheimer's Disease: A Systematic Review

Advancing age is one of the risk factors for developing many diseases, including cancer, cardiovascular disorders, and neurodegenerative alterations, such as mild cognitive impairment (MCI), and Alzheimer's Disease (AD). Studies have indicated that supplementation with resveratrol (RSV) might improve cerebrovascular function and reduce the risk of developing dementia. Thus, the aim of this systematic review was to assess the effects of RSV on MCI and AD. MEDLINE-PubMed, Cochrane, and EMBASE were used to perform the search, and PRISMA guidelines were followed. Five studies met the eligible criteria; three with AD and two with MCI. In AD patients, the use of RSV reduces Aβ levels, improves brain volume, reduces the Mini-mental status score, and improves AD scores. In patients with MCI, this polyphenol prevents decline in Standard Volumes of Interest and increases the Resting-state Functional Connectivity score. RSV can activate the human silent information regulator 2/sirtuin 1 (Sirt-1) and can inhibit the cyclooxygenase-2 (COX-2), 5-lipoxygenase, and nuclear factor-κB, resulting in the reduction of the proinflammation pathways. It is also associated with the increase in the levels of interleukin (IL)-10 and reduction of interferon-γ and IL-17. Both anti-inflammatory and antioxidant effects can be related to preventing neurodegenerative diseases, doing maintenance, and enabling the recovery of these conditions directly related to inflammation and oxidative stress. We suggest that the use of RSV can bring beneficial effects to patients with MCI or AD.

Strategies to Improve Drug Strength in Nasal Preparations for Brain Delivery of Low Aqueous Solubility Drugs

Intranasal administration is a promising route for brain drug delivery. However, it can be difficult to formulate drugs that have low water solubility into high strength intranasal solutions. Hence, the purpose of this work was to review the strategies that have been used to increase drug strength in intranasal liquid formulations. Three main groups of strategies are: the use of solubilizers (change in pH, complexation and the use cosolvents/surfactants); incorporation of the drugs into a carrier nanosystem; modifications of the molecules themselves (use of salts or hydrophilic prodrugs). The use of high amounts of cosolvents and/or surfactants and pH decrease below 4 usually lead to local adverse effects, such as nasal and upper respiratory tract irritation. Cyclodextrins and (many) different carrier nanosystems, on the other hand, could be safer for intranasal administration at reasonably high concentrations, depending on selected excipients and their dose. While added attributes such as enhanced permeation, sustained delivery, or increased direct brain transport could be achieved, a great effort of optimization will be required. On the other hand, hydrophilic prodrugs, whether co-administered with a converting enzyme or not, can be used at very high concentrations, and have resulted in a fast prodrug to parent drug conversion and led to high brain drug levels. Nevertheless, the choice of which strategy to use will always depend on the characteristics of the drug and must be a case-by-case approach.

Self-gelation involved in the transformation of resveratrol and piperine from a co-amorphous system into a co-crystal system

Self-gelation of co-amorphous system promotes the transformation into its co-crystal system during dissolution.

Diabetes and Alzheimer's Disease: Might Mitochondrial Dysfunction Help Deciphering the Common Path?

A growing number of clinical and epidemiological studies support the hypothesis of a tight correlation between type 2 diabetes mellitus (T2DM) and the development risk of Alzheimer's disease (AD). Indeed, the proposed definition of Alzheimer's disease as type 3 diabetes (T3D) underlines the key role played by deranged insulin signaling to accumulation of aggregated amyloid beta (Aβ) peptides in the senile plaques of the brain. Metabolic disturbances such as hyperglycemia, peripheral hyperinsulinemia, dysregulated lipid metabolism, and chronic inflammation associated with T2DM are responsible for an inefficient transport of insulin to the brain, producing a neuronal insulin resistance that triggers an enhanced production and deposition of Aβ and concomitantly contributes to impairment in the micro-tubule-associated protein Tau, leading to neural degeneration and cognitive decline. Furthermore, the reduced antioxidant capacity observed in T2DM patients, together with the impairment of cerebral glucose metabolism and the decreased performance of mitochondrial activity, suggests the existence of a relationship between oxidative damage, mitochondrial impairment, and cognitive dysfunction that could further reinforce the common pathophysiology of T2DM and AD. In this review, we discuss the molecular mechanisms by which insulin-signaling dysregulation in T2DM can contribute to the pathogenesis and progression of AD, deepening the analysis of complex mechanisms involved in reactive oxygen species (ROS) production under oxidative stress and their possible influence in AD and T2DM. In addition, the role of current therapies as tools for prevention or treatment of damage induced by oxidative stress in T2DM and AD will be debated.

Thioredoxin-interacting protein (TXNIP) as a target for Alzheimer's disease: flavonoids and phenols

Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid plaques and tangles that have become the fifth leading cause of death worldwide. Previous studies have found that thioredoxin interacting protein (TXNIP) expression was increased during the development of AD neurons. TXNIP separates from the TXNIP-thioredoxin complex, and the TXNIP-NLRP3 complex assembles ASC and pro-caspase-1 to form the NLRP3 inflammasome, which triggers AD inflammation and apoptosis. CB-dock was used to explore whether 21 natural flavonoids and phenols target TXNIP based on references. Docking results showed that rutin, puerarin, baicalin, luteolin and quercetin are the most potent TXNIP inhibitors, and among them, rutin as the most effective flavonoid. And rosmarinic acid is the most potent TXNIP inhibitor of phenols. These phytochemicals could be helpful to find the lead compounds in designing and developing novel agents for Alzheimer's disease.