The protective mechanisms of polydatin in cerebral ischemia

Polydatin attenuates Alzheimer's disease induced by aluminum chloride in rats: evidence for its antioxidant and anti-inflammatory effects

Background

Considering the complex pathophysiological mechanisms behind Alzheimer's disease (AD), a few drugs for managing related cognitive symptoms have been approved. The phytochemical resveratrol has shown promising anti-inflammatory and antioxidant effects in AD, but it has low bioavailability. Chemical modification of resveratrol to its glycosylated form, polydatin (PD), significantly increases its bioavailability and bioactivity.

Purpose

The study aimed to investigate the therapeutic potential and mechanisms of action of PD against AD in rats.

Material and method

AD was caused by an intraperitoneal (i.p.) administration of aluminum chloride (AlCl3). Six groups of six rats each were defined as sham, negative control (AlCl3), positive control (Donepezil), and treatments (PD 5, 10, and 20 mg/kg, i.p.). On days 7, 8, 14, and 15, the rats' behavioral changes were assessed by the open field, Y-maze test, passive avoidance test, and elevated plus maze tests. At the end of the study, the blood samples were collected to assess the levels of glutathione (GSH), catalase (CAT), and nitrite, as well as the activity of matrix metalloproteinases (MMPs). Furthermore, hippocampal brain tissue was removed and used for histological investigations.

Results and discussion

The findings revealed that PD injections at three different doses (5, 10, and 20 mg/kg) improved cognitive and other behavioral impairments. Furthermore, PD improved the antioxidant capacity by increasing GSH and CAT while decreasing serum nitrite levels. PD showed anti-inflammatory effects by reducing the activity of inflammatory MMP-9, while elevating the activity of anti-inflammatory MMP-2. PD also modulated pathogenic changes in the hippocampal brain tissue.

Conclusion

PD alleviated cognitive and other behavioral impairments in AD rats by enhancing antioxidant defenses and reducing neuroinflammation.

Rhubarb with Different Cooking Methods Restored the Gut Microbiota Dysbiosis and SCFAs in Ischemic Stroke Mice

Ischemic stroke is a significant public health problem worldwide. Growing evidence has shown gut microbiota served a vital function in ischemic stroke. Rhubarb, always used after processing, is a promising therapy for ischemic stroke. However, the possible mechanism of rhubarb with different cooking methods has remained unclear. Herein, the constitutes of steaming rhubarb (SP), raw rhubarb (RP), and nine steaming nine sun-drying rhubarb (NSP) were identified via LC-QTOF-MS. The middle cerebral artery occlusion (MCAO) mice model was constructed. Infarction area, neurological score, Nissl staining, IBA-1 immunofluorescence, and ELISA were performed to confirm the neuroprotective effect of SP, RP, and NSP. The gut microbiota in fetal was studied via 16sRNA sequencing, and the level of short-chain fatty acids (SCFAs) in brain and gut were measured via GC-MS. The function of microbiota signature was identified through PICRUSt2; the possible mechanism was studied. SP, RP, and NSP alleviated the neurological dysfunction, decreased the inflammation, suppressed dysbiosis of gut microbiota, restored SCFA-producing bacteria, and enhanced the SCFA level in MCAO mice. Moreover, the NSP and SP enriched the proportion of anti-inflammation and beneficial bacteria, deleted the proportion of pro-inflammation. It observed energy metabolism was involved in the possible mechanism of rhubarb; activities of COXI and Na+-K+-ATPase were increased in the brain of NSP and SP treatment mice. Furthermore, the expression of GLUT4 and PFK1 (the energy metabolism-related genes) was elevated in the brain after RP, NSP and SP administration. In this study, it provided proof for the treatment of ischemic stroke with rhubarb. Rhubarb restored the gut microbiota and regulated the expression of GLUT4 and PFK1 to alleviate ischemic stroke.

Polydatin ameliorates early brain injury after subarachnoid hemorrhage through up-regulating SIRT1 to suppress endoplasmic reticulum stress

Objective

This study aims to investigate the inhibitory effect of Polydatin (PD) on endoplasmic reticulum (ER) stress following subarachnoid hemorrhage (SAH) and to elucidate the underlying mechanisms.

Methods

A standard intravascular puncture model was established to mimic SAH in mice. Neurological functions were assessed using neurological scoring, Grip test, and Morris water maze. Brain edema and Evans blue extravasation were measured to evaluate blood-brain barrier permeability. Western blot and quantitative real-time polymerase chain reaction (PCR) analyses were performed to examine protein and mRNA expressions related to ER stress. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was used to detect cell apoptosis, and transmission electron microscopy was used to observe the ultrastructure of the endoplasmic reticulum.

Results

The results indicated that PD significantly reduced brain edema and Evans blue extravasation after SAH, improving neurological function. Compared to the SAH group, the expression levels of ER stress-related proteins including glucose-regulated protein 78 (GRP78), phosphorylated protein kinase R-like endoplasmic reticulum kinase (p-PERK), phosphorylated eukaryotic initiation factor 2α (p-eIF2α), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP), were significantly lower in the PD-treated group. Moreover, PD significantly enhances the protein expression of Sirtuin 1 (SIRT1). Validation with sh-SIRT1 confirmed the critical role of SIRT1 in ER stress, with PD's inhibitory effect on ER stress being dependent on SIRT1 expression. Additionally, PD attenuated ER stress-mediated neuronal apoptosis and SAH-induced ferroptosis through upregulation of SIRT1.

Conclusion

PD alleviates ER stress following SAH by upregulating SIRT1 expression, thereby mitigating early brain injury. The protective effects of PD are mediated through SIRT1, which inhibits ER stress and reduces neuronal apoptosis and ferroptosis.

Polydatin and Nicotinamide Rescue the Cellular Phenotype of Mitochondrial Diseases by Mitochondrial Unfolded Protein Response (mtUPR) Activation

Primary mitochondrial diseases result from mutations in nuclear DNA (nDNA) or mitochondrial DNA (mtDNA) genes, encoding proteins crucial for mitochondrial structure or function. Given that few disease-specific therapies are available for mitochondrial diseases, novel treatments to reverse mitochondrial dysfunction are necessary. In this work, we explored new therapeutic options in mitochondrial diseases using fibroblasts and induced neurons derived from patients with mutations in the GFM1 gene. This gene encodes the essential mitochondrial translation elongation factor G1 involved in mitochondrial protein synthesis. Due to the severe mitochondrial defect, mutant GFM1 fibroblasts cannot survive in galactose medium, making them an ideal screening model to test the effectiveness of pharmacological compounds. We found that the combination of polydatin and nicotinamide enabled the survival of mutant GFM1 fibroblasts in stress medium. We also demonstrated that polydatin and nicotinamide upregulated the mitochondrial Unfolded Protein Response (mtUPR), especially the SIRT3 pathway. Activation of mtUPR partially restored mitochondrial protein synthesis and expression, as well as improved cellular bioenergetics. Furthermore, we confirmed the positive effect of the treatment in GFM1 mutant induced neurons obtained by direct reprogramming from patient fibroblasts. Overall, we provide compelling evidence that mtUPR activation is a promising therapeutic strategy for GFM1 mutations.

Glycosylation: A new signaling paradigm for the neurovascular diseases

A wide range of life-threatening conditions with complicated pathogenesis involves neurovascular disorders encompassing Neurovascular unit (NVU) damage. The pathophysiology of NVU is characterized by several features including tissue hypoxia, stimulation of inflammatory and angiogenic processes, and the initiation of intricate molecular interactions, collectively leading to an elevation in blood-brain barrier permeability, atherosclerosis and ultimately, neurovascular diseases. The presence of compelling data about the significant involvement of the glycosylation in the development of diseases has sparked a discussion on whether the abnormal glycosylation may serve as a causal factor for neurovascular disorders, rather than being just recruited as a secondary player in regulating the critical events during the development processes like embryo growth and angiogenesis. An essential tool for both developing new anti-ischemic therapies and understanding the processes of ischemic brain damage is undertaking pre-clinical studies of neurovascular disorders. Together with the post-translational modification of proteins, the modulation of glycosylation and its enzymes implicates itself in several abnormal activities which are known to accelerate neuronal vasculopathy. Despite the failure of the majority of glycosylation-based preclinical and clinical studies over the past years, there is a significant probability to provide neuroprotection utilizing modern and advanced approaches to target abnormal glycosylation activity at embryonic stages as well. This article focuses on a variety of experimental evidence to postulate the interconnection between glycosylation and vascular disorders along with possible treatment options.

Mechanisms of polydatin against spinal cord ischemia-reperfusion injury based on network pharmacology, molecular docking and molecular dynamics simulation

BACKGROUND

Polydatin has shown considerable pharmacological activities in ischemia-reperfusion injuries of various organs. However, its effects and mechanisms in spinal cord ischemia-reperfusion injury have not been fully established. In this study, the mechanisms of polydatin against spinal cord ischemia-reperfusion injury were investigated via network pharmacology, molecular docking and molecular dynamics simulation.

METHODS

Spinal cord ischemia-reperfusion injury-related targets were obtained from the GeneCards database, while polydatin-related action targets were obtained from the CTD and SwissTarget databases. A protein-protein interaction network of potential targets was constructed using the String platform. After selecting the potential key targets, GO functional enrichment and KEGG pathway enrichment analyses were performed via the Metascape database, and a network map of "drug-target-pathway-disease" constructed. The relationships between polydatin and various key targets were assessed via molecular docking. Molecular dynamics simulation was conducted for optimal core protein-compound complexes obtained by molecular docking.

RESULTS

Topological analysis of the PPI network revealed 14 core targets. GO functional enrichment analysis revealed that 435 biological processes, 12 cell components and 29 molecular functions were enriched while KEGG pathway enrichment analysis revealed 91 enriched signaling pathways. Molecular docking showed that polydatin had the highest binding affinity for MAPK3, suggesting that MAPK3 is a key target of polydatin against spinal cord ischemia-reperfusion injury. Molecular dynamics simulations revealed good binding abilities between polydatin and MAPK3.

CONCLUSIONS

Polydatin exerts its effects on spinal cord ischemia-reperfusion injury through multiple targets and pathways. MAPK3 may be a key target of polydatin in spinal cord ischemia-reperfusion injury.

Advances in the pharmacological study of Chinese herbal medicine to alleviate diabetic nephropathy by improving mitochondrial oxidative stress

Diabetic nephropathy (DN) is one of the serious complications of diabetes mellitus, primarily arising from type 2 diabetes (T2DM), and can progress to chronic kidney disease (CKD) and end stage renal disease (ESRD). The pathogenesis of DN involves various factors such as hemodynamic changes, oxidative stress, inflammatory response, and lipid metabolism disorders. Increasing attention is being given to DN caused by oxidative stress in the mitochondrial pathway, prompting researchers to explore drugs that can regulate these target pathways. Chinese herbal medicine, known for its accessibility, rich historical usage, and remarkable efficacy, has shown promise in ameliorating renal injury caused by DN by modulating oxidative stress in the mitochondrial pathway. This review aims to provide a reference for the prevention and treatment of DN. Firstly, we outline the mechanisms by which mitochondrial dysfunction impairs DN, focusing on outlining the damage to mitochondria by oxidative stress. Subsequently, we describe the process by which formulas, herbs and monomeric compounds protect the kidney by ameliorating oxidative stress in the mitochondrial pathway. Finally, the rich variety of Chinese herbal medicine, combined with modern extraction techniques, has great potential, and as we gradually understand the pathogenesis of DN and research techniques are constantly updated, there will be more and more promising therapeutic targets and herbal drug candidates. This paper aims to provide a reference for the prevention and treatment of DN.

Emerging Treatment Strategies for Cerebral Ischemia-Reperfusion Injury

Cerebral ischemia-reperfusion injury (CI/RI) injury is a common feature of ischemic stroke which occurs when the blood supply is restored after a period of ischemia in the brain. Reduced blood-flow to the brain during CI/RI compromises neuronal cell health as a result of mitochondrial dysfunction, oxidative stress, cytokine production, inflammation and tissue damage. Reperfusion therapy during CI/RI can restore the blood flow to ischemic regions of brain which are not yet infarcted. The long-term goal of CI/RI therapy is to reduce stroke-related neuronal cell death, disability and mortality. A range of drug and interventional therapies have emerged that can alleviate CI/RI mediated oxidative stress, inflammation and apoptosis in the brain. Herein, we review recent studies on CI/RI interventions for which a mechanism of action has been described and the potential of these therapeutic modalities for future use in the clinic.

Polydatin Ameliorates High Fructose-Induced Podocyte Oxidative Stress via Suppressing HIF-1α/NOX4 Pathway

Long-term high fructose intake drives oxidative stress, causing glomerular podocyte injury. Polydatin, isolated from Chinese herbal medicine Polygonum cuspidatum, is used as an antioxidant agent that protects kidney function. However, it remains unclear how polydatin prevents oxidative stress-driven podocyte damage. In this study, polydatin attenuated high fructose-induced high expression of HIF-1α, inhibited NOX4-mediated stromal cell-derived factor-1α/C-X-C chemokine receptor type 4 (SDF-1α/CXCR4) axis activation, reduced reactive oxygen species (ROS) production in rat glomeruli and cultured podocytes. As a result, polydatin up-regulated nephrin and podocin, down-regulated transient receptor potential cation channel 6 (TRPC6) in these animal and cell models. Moreover, the data from HIF-1α siRNA transfection showed that high fructose increased NOX4 expression and aggravated SDF-1α/CXCR4 axis activation in an HIF-1α-dependent manner, whereas polydatin down-regulated HIF-1α to inhibit NOX4 and suppressed SDF-1α/CXCR4 axis activation, ameliorating high fructose-induced podocyte oxidative stress and injury. These findings demonstrated that high fructose-driven HIF-1α/NOX4 pathway controlled podocyte oxidative stress damage. Intervention of this disturbance by polydatin could help the development of the therapeutic strategy to combat podocyte damage associated with high fructose diet.

Polydatin: Pharmacological Mechanisms, Therapeutic Targets, Biological Activities, and Health Benefits

Polydatin is a natural potent stilbenoid polyphenol and a resveratrol derivative with improved bioavailability. Polydatin possesses potential biological activities predominantly through the modulation of pivotal signaling pathways involved in inflammation, oxidative stress, and apoptosis. Various imperative biological activities have been suggested for polydatin towards promising therapeutic effects, including anticancer, cardioprotective, anti-diabetic, gastroprotective, hepatoprotective, neuroprotective, anti-microbial, as well as health-promoting roles on the renal system, the respiratory system, rheumatoid diseases, the skeletal system, and women's health. In the present study, the therapeutic targets, biological activities, pharmacological mechanisms, and health benefits of polydatin are reviewed to provide new insights to researchers. The need to develop further clinical trials and novel delivery systems of polydatin is also considered to reveal new insights to researchers.

Anti-Inflammatory Effects of Natural Products on Cerebral Ischemia

Cerebral ischemia with high mortality and morbidity still requires the effectiveness of medical treatments. A growing number of investigations have shown strong links between inflammation and cerebral ischemia. Natural medicine’s treatment methods of cerebral ischemic illness have amassed a wealth of treatment experience and theoretical knowledge. This review summarized recent progress on the disease inflammatory pathways as well as 26 representative natural products that have been routinely utilized to treat cerebral ischemic injury. These natural products have exerted anti-inflammatory effects in cerebral ischemia based on their inflammatory mechanisms, including their inflammatory gene expression patterns and their related different cell types, and the roles of inflammatory mediators in ischemic injury. Overall, the combination of the potential therapeutic interventions of natural products with the inflammatory mechanisms will make them be applicable for cerebral ischemic patients in the future.

Old dog, new tricks: Polydatin as a multitarget agent for current diseases

Polydatin (PD) is a natural single-crystal product that is primarily extracted from the traditional plant Polygonum cuspidatum Sieb. et Zucc. Early research showed that PD exhibited a variety of biological activities. PD has attracted increasing research interest since 2014, but no review comprehensively summarized the new findings. A great gap between its biological activities and drug development remains. It is necessary to summarize new findings on the pharmacological effects of PD on current diseases. We propose that PD will most likely be used in cardiac and cerebral ischaemia/reperfusion-related diseases and atherosclerosis in the future. The present work classified these new findings according to diseases and summarized the main effects of PD via specific mechanisms of action. In summary, we found that PD played a therapeutic role in a variety of diseases, primarily via five mechanisms: antioxidative effects, antiinflammatory effects, regulation of autophagy and apoptosis, maintenance of mitochondrial function, and lipid regulation.

Development of a novel UPLC-MS/MS method for the simultaneously quantification of polydatin and resveratrol in plasma: Application to a pharmacokinetic study in rats

The purpose of this study is to develop a sensitive LC-MS-MS method to simultaneously quantify polydatin and its metabolite, resveratrol, for its application in a pharmacokinetic (PK) study and to determine polydatin hydrolysis by microflora. A Shimadzu UHPLC system coupled to an AB Sciex QTrap 4000 mass spectrometer was used for the analysis. Separation was achieved using an Acquity BEH C18 column (2.1 × 50 mm) with acetonitrile and 0.1% formic acid as the mobile phases. Analysis was performed under negative ionization mode using the multiple reaction monitoring (MRM) approach. The method was linear in the range of 9.77-1250 nM for both resveratrol and polydatin with correlation coefficient values >0.99. Themethodhas been shown to be reproducible, with intra- and inter-day accuracy and precision ±10.4% of nominal values, for both analytes. The average extraction recovery rates were 81.78-98.3% for polydatin and 86.4-103.2% for resveratrol, respectively. Matrix effect was in the acceptable range (<15%). The analytes in plasma were found to be stable under bench-top, freeze-thaw, and storage (-4 °C) conditions. The metabolic studies showed that polydatin can be rapidly hydrolyzed by rat fecal S9 fractions and PK studies showed that both polydatin and resveratrol were exposed in the plasma and variable tissues. This novel UPLC-MS-MS method can quantify the levels of both polydatin and its major metabolite resveratrol in biological samples.

Multifunctional Metal-Organic Framework as a Versatile Nanoplatform for Aβ Oligomer Imaging and Chemo-Photothermal Treatment in Living Cells

In view of the close association of β-amyloid oligomers (AβO) with the clinical development of Alzheimer's disease (AD) symptoms, it is urgent to design a promising sensing and therapeutic strategy that can target AβO for preventing or delaying the onset of AD. Herein, a core-shell nanocomposite CeONP-Res-PCM@ZIF-8/polydopamine (PDA) was synthesized through an in situ encapsulated strategy, in which resveratrol (Res), ceria nanoparticles (CeONPs), and PCM (tetradecanol) were embedded into the ZIF-8/PDA matrix via a water-based mild approach. Using the AβO aptamer, the ability of CeONP-Res-PCM@ZIF-8/PDA/Apt as the fluorescent sensing platform for AβO detection and intracellular imaging was demonstrated. The nanocomposite was high in Res loading (27.5%) and could be activated to release the encapsulated Res upon illumination with NIR through PCM regulation. Moreover, due to the synergetic interactions of PDA, CeONPs, and Res in one system, CeONP-Res-PCM@ZIF-8/PDA/Apt nanocomposites exhibited multifunctional effects on inhibiting Aβ aggregation, degrading Aβ fibrils, and alleviating Aβ-induced oxidative stress and neural apoptosis. These therapeutic effects could be enhanced under NIR irradiation by virtue of the excellent photothermal property of PDA. As far as we know, there is no report of using ZIF-8-based materials for simultaneous sensing and therapeutic applications. This work boosted the development of multifunctional nanoagents for biomedical research studies.

The Neuroprotective Role of Polydatin: Neuropharmacological Mechanisms, Molecular Targets, Therapeutic Potentials, and Clinical Perspective

Neurodegenerative diseases (NDDs) are one of the leading causes of death and disability in humans. From a mechanistic perspective, the complexity of pathophysiological mechanisms contributes to NDDs. Therefore, there is an urgency to provide novel multi-target agents towards the simultaneous modulation of dysregulated pathways against NDDs. Besides, their lack of effectiveness and associated side effects have contributed to the lack of conventional therapies as suitable therapeutic agents. Prevailing reports have introduced plant secondary metabolites as promising multi-target agents in combating NDDs. Polydatin is a natural phenolic compound, employing potential mechanisms in fighting NDDs. It is considered an auspicious phytochemical in modulating neuroinflammatory/apoptotic/autophagy/oxidative stress signaling mediators such as nuclear factor-κB (NF-κB), NF-E2–related factor 2 (Nrf2)/antioxidant response elements (ARE), matrix metalloproteinase (MMPs), interleukins (ILs), phosphoinositide 3-kinases (PI3K)/protein kinase B (Akt), and the extracellular regulated kinase (ERK)/mitogen-activated protein kinase (MAPK). Accordingly, polydatin potentially counteracts Alzheimer’s disease, cognition/memory dysfunction, Parkinson’s disease, brain/spinal cord injuries, ischemic stroke, and miscellaneous neuronal dysfunctionalities. The present study provides all of the neuroprotective mechanisms of polydatin in various NDDs. Additionally, the novel delivery systems of polydatin are provided regarding increasing its safety, solubility, bioavailability, and efficacy, as well as developing a long-lasting therapeutic concentration of polydatin in the central nervous system, possessing fewer side effects.

Neuroprotective Effects of Resveratrol in Ischemic Brain Injury

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

Cerebral ischemic stroke and different approaches for treatment of stroke

Background

Cerebral ischemia can be considered a lethal disease as it is a leading cause of death worldwide with no prompt line of treatment. The factors which make this disease more fatal are failure of drugs while crossing BBB, very low availability of the drug in the brain, inefficiency of drug molecule in the clinical studies, limited availability of clinical data, lack of awareness about this disease, and many more.

Main body

This review focuses on reasons and mechanisms of stroke, classification of brain ischemia; it also reveals the current scenario of stroke in India. Very few drugs are effective for the treatment of stroke. This compilation furnishes conventional and recent treatments of stroke along with their hurdles like the gap between preclinical and clinical studies. This review also suggests effective routes of administration of drugs for the treatment of brain ischemia specifically nose-to-brain route and effectiveness of different dosage forms precisely nanoformulations, as the most effective dosage form.

Conclusion

By following different guidelines and treatments, the risk of brain ischemia can be minimized as well as some advanced techniques for the treatment of this disease proving their efficiency. One of the important aspects in the success of the treatment for this disease is the route of administration of the drug. Among all routes, intranasal drug delivery presents a potential approach and is supposed to be the next-generation therapy for brain disorders. The nose-to-brain route is very effective, and it shows some promising results in case of stroke treatment. The strategy is still under investigation despite various successful lab-scale studies; there are numerous challenges to reach the product in the market. Research is going on to get a better understanding of this strategy. We believe that detailed studies to resolve pitfalls will lead to the successful development of an intranasal formulation for the management of ischemic brain injury such as stroke.

Polyphenols and Ischemic Stroke: Insight into One of the Best Strategies for Prevention and Treatment

Ischemic stroke (IS) is still among the leading causes of death and disability worldwide. The pathogenic mechanisms beyond its development are several and are complex and this is the main reason why a functional therapy is still missed. The beneficial effects of natural compounds against cardiovascular diseases and IS have been investigated for a long time. In this article, we reviewed the association between the most studied polyphenols and stroke protection in terms of prevention, effect on acute phase, and rehabilitation. We described experimental and epidemiological studies reporting the role of flavonols, phenolic acid, and stilbens on ischemic mechanisms leading to stroke. We analyzed the principal animal models used to evaluate the impact of these micronutrients to cerebral blood flow and to molecular pathways involved in oxidative stress and inflammation modulation, such as sirtuins. We reported the most significant clinical trials demonstrated as the persistent use of polyphenols is clinically relevant in terms of the reduction of vascular risk factors for IS, such as Atrial Fibrillation. Interestingly, different kinds of polyphenols provide brain protection by activating different pathways and mechanisms, like inducing antithrombotic effect, such as Honokiol. For this reason, we discussed an appropriate integrative use of them as a possible therapeutic alternative against stroke.

SIRT1 provides new pharmacological targets for polydatin through its role as a metabolic sensor

The SIRT family of proteins constitutes highly conserved deacetylases with diverse and extensive functions. These proteins have specific biological functions, including regulation of transcription, cell cycle, cell differentiation, apoptosis, stress, metabolism, and genomic stability. Polydatin is a monocrystalline compound isolated from a Chinese herb, Polygonum cuspidatum. The pharmacological mechanisms of polydatin are mostly unclear but involve members of the SIRT protein family, among which SIRT1 plays a vital role. Polydatin is usually considered a potential SIRT1 activator. This review summarizes the signaling mechanism of polydatin involving SIRT1 and discusses the roles of related signal molecules such as PGC-1α, Nrf2, p38-MAPK, NLPR3 inflammasome, and p53. Further, we describe the metabolic regulation of related biological macromolecules and demonstrate that SIRT1, as a metabolic sensor, may act as a new pharmacological target for polydatin.

Polydatin Attenuates OGD/R-Induced Neuronal Injury and Spinal Cord Ischemia/Reperfusion Injury by Protecting Mitochondrial Function via Nrf2/ARE Signaling Pathway

Spinal cord ischemia/reperfusion injury (SCII) is a devastating complication of spinal or thoracic surgical procedures and can lead to paraplegia or quadriplegia. Neuronal cell damage involving mitochondrial dysfunction plays an important role in the pathogenesis of SCII. Despite the availability of various treatment options, there are currently no mitochondria-targeting drugs that have proven effective against SCII. Polydatin (PD), a glucoside of resveratrol, is known to preserve mitochondrial function in central nervous system (CNS) diseases. The aim of the present study was to explore the neuro- and mito-protective functions of PD and its underlying mechanisms. An in vitro model of SCII was established by exposing spinal cord motor neurons (SMNs) to oxygen–glucose-deprivation/reperfusion (OGD/R), and the cells were treated with different dosages of PD for varying durations. PD improved neuronal viability and protected against OGD/R-induced apoptosis and mitochondrial injury in a dose-dependent manner. In addition, PD restored the activity of neuronal mitochondria in terms of mitochondrial membrane potential (MMP), intracellular calcium levels, mitochondrial permeability transition pore (mPTP) opening, generation of reactive oxygen species (ROS), and adenosine triphosphate (ATP) levels. Mechanistically, PD downregulated Keap1 and upregulated Nrf2, NQO-1, and HO-1 in the OGD/R-treated SMNs. Likewise, PD treatment also reversed the neuronal and mitochondrial damage induced by SCII in a mouse model. Furthermore, the protective effects of PD were partially blocked by the Nrf2 inhibitor. Taken together, PD relieves mitochondrial dysfunction-induced neuronal cell damage by activating the Nrf2/ARE pathway and is a suitable therapeutic option for SCII.

Natural Antioxidants Improve the Vulnerability of Cardiomyocytes and Vascular Endothelial Cells under Stress Conditions: A Focus on Mitochondrial Quality Control

Cardiovascular disease has become one of the main causes of human death. In addition, many cardiovascular diseases are accompanied by a series of irreversible damages that lead to organ and vascular complications. In recent years, the potential therapeutic strategy of natural antioxidants in the treatment of cardiovascular diseases through mitochondrial quality control has received extensive attention. Mitochondria are the main site of energy metabolism in eukaryotic cells, including myocardial and vascular endothelial cells. Mitochondrial quality control processes ensure normal activities of mitochondria and cells by maintaining stable mitochondrial quantity and quality, thus protecting myocardial and endothelial cells against stress. Various stresses can affect mitochondrial morphology and function. Natural antioxidants extracted from plants and natural medicines are becoming increasingly common in the clinical treatment of diseases, especially in the treatment of cardiovascular diseases. Natural antioxidants can effectively protect myocardial and endothelial cells from stress-induced injury by regulating mitochondrial quality control, and their safety and effectiveness have been preliminarily verified. This review summarises the damage mechanisms of various stresses in cardiomyocytes and vascular endothelial cells and the mechanisms of natural antioxidants in improving the vulnerability of these cell types to stress by regulating mitochondrial quality control. This review is aimed at paving the way for novel treatments for cardiovascular diseases and the development of natural antioxidant drugs.

Polydatin-Induced Direct and Bystander Effects in A549 Lung Cancer Cell Line

Polydatin, a natural analogue of resveratrol, has many biological activities. The better bioavailability of polydatin than resveratrol makes it an ideal candidate for therapy. Polydatin has protective effects against various diseases (cardiovascular, neurological, inflammatory, etc.) including cancer. However, its mechanism of action has not been fully established. Therefore, the present study was initiated to explore the mechanism/s associated with chemotherapeutic effects of polydatin in in vitro using lung cancer A549 cells. The effects of polydatin on cell proliferation and metastasis were assessed using various parameters like MTT, colony formation, DNA damage, apoptosis, and wound healing. Polydatin treatment reduced the proliferation of A549 cells by inducing DNA damage and cell cycle arrest in a concentration-dependent manner. The inhibition of cell proliferation was induced by dual mechanism of senescence and apoptosis. Proteins involved in various pathways were studied using western blotting and immunocytochemistry. Interestingly, senescent and apoptotic cells induced a differential bystander response (proliferative/toxic) in naïve A549 cells. Our results show that polydatin can induce both senescence and apoptosis in A549 cells in a concentration-dependent manner and the differential bystander effects induced by polydatin are regulated by mTOR pathway.

Protective Effects of Polydatin Against Dementia-Related Disorders

Dementia is a collection of symptoms affecting a person's cognition. Dementia is debilitating, and therefore, finding an effective treatment is of utmost importance. Resveratrol, which exhibits neuroprotective effects, has low bioavailability. However, its glucoside polydatin is more bioavailable. Here, the evidence that supports the protective role of polydatin against dementia- related diseases such as Alzheimer's disease, vascular dementia, alcohol-related dementia, and Lewy body dementias is presented. The beneficial effects of polydatin from a mechanistic perspective are specifically emphasized in this review. Future directions in this area of research are also discussed.

Antioxidant and Anti-inflammatory Properties of Yttrium Oxide Nanoparticles: New Insights into Alleviating Diabetes

BACKGROUND

Diabetes mellitus is a metabolic disease that requires immediate attention. Oxidative stress that leads to the generation of reactive oxygen species is a contributing factor to the disease progression. Yttrium oxide nanoparticles (Y₂O₃ NPs) have a profound effect on alleviating oxidative damage.

METHODS

The literature related to Y₂O₃ NPs and oxidative stress has been thoroughly searched using PubMed and Scopus databases and relevant studies from inception until August 2020 were included in this scoping review.

RESULTS

Y₂O₃ NPs altered oxidative stress-related biochemical parameters in different disease models including diabetes.

CONCLUSION

Although Y₂O₃ NPs are a promising antidiabetic agent due to their antioxidant and anti- inflammatory properties, more studies are required to further elucidate the pharmacological and toxicological properties of these nanoparticles.

The Connotation of Variances in the Risk Predictors, Medications, Homocysteine, and Homocysteine Pathway Gene Polymorphisms with CVA/Stroke

Cerebrovascular accidents (CVAs) are vascular multifactorial, multigenic ailments with intricate genetic, environmental risk influences. The present study aimed to establish affiliation of CVAs/stroke with blood parameters, differences in prescribed drugs consumption, and with differences in homocysteine pathway genes polymorphisms. The participants in study included controls n  = 251, transient ischemic attack (TIA) patients n  = 16, and stroke cases n  = 122, respectively, (total participants, n  = 389). The analyzed single nucleotide polymorphisms (SNPs) included C677T(rs1801133), A1298C(rs1801131) of methylene tetrahydrofolate reductase ( MTHFR ), A2756G(rs1805087) of methyl tetrahydrofolate homocysteine methyltransferase/methionine synthase ( MS ), and the A192G(rs662) of paraoxonase 1( PON1 ) genes, all validated by tetra-primer allele refractory mutation system polymerase chain reaction (T-ARMS-PCR). The insertion deletion (I/D; rs4646994) polymorphism in angiotensin converting enzyme ( ACE ) gene was analyzed using routine PCR. All studied traits were scrutinized through analysis of variance (ANOVA), and later through regression analysis. Through ANOVA and multiple comparison, there was association of CVA with serum homocysteine, cholesterol, and with diastolic blood pressure readings. When data was subjected to regression, serum homocysteine and diastolic blood pressure (significant through ANOVA), as well as two additional traits, high-density lipoproteins (HDL), and rs1801133 MTHFR SNP sustained statistical significance and noteworthy odds in relation to CVA and stroke. The ailments affecting cerebral vasculature are mutifactorial, whereby genes, proteins, and environmental cues all exert cumulative effects enhancing CVA risk. The current study emphasizes that SNPs and variation in circulating biomarkers can be used for screening purposes and for reviewing their effects in stroke/CVA-linked risk progression.

The potential role of nanoyttria in alleviating oxidative stress biomarkers: Implications for Alzheimer's disease therapy

Alzheimer's disease (AD) is a fatal neurodegenerative disease that requires immediate attention. Oxidative stress that leads to the generation of reactive oxygen species is a contributing factor to the disease progression by promoting synthesis and deposition of amyloid-β, the main hallmark protein in AD. It has been previously demonstrated that nanoyttria possesses antioxidant properties and can alleviate cellular oxidative injury in various toxicity and disease models. This review proposed that nanoyttria could be used for the treatment of AD. In this paper, the evidence on the antioxidant potential of nanoyttria is presented and its prospects on AD therapy are discussed.

Selective separation and purification of polydatin by molecularly imprinted polymers from the extract of Polygoni Cuspidati Rhizoma et Radix, rats' plasma and urine

Molecularly imprinted polymers (MIPs) based on polydatin were prepared by precipitation polymerization method. Synthesis process of MIPs was optimized by discussion of functional monomers, porogens and the molar ratio of template- functional monomer-cross linker. Then, MIPs were prepared with polydatin as the template, 4-vinyl pyridine as the functional monomer, ethylene glycol dimethyl acrylate as the cross linker, acetonitrile as the porogen and the molar ratio of template-monomer-cross linker at 1:10:20. Scanning electron microscopy and Fourier transform infrared spectrometer were used to inspect macroscale and chemical bond of MIPs. Adsorption capability and selectivity of MIPs to polydatin were investigated by carrying out the static, dynamic and selective experiments. The results showed MIPs performed high adsorption ability and selectivity to polydatin, indicating MIPs could be used to separate and enrich polydatin from the complex systems. Finally, MIPs were applied as the adsorbent for isolation and purification of polydatin from the extract of Polygoni Cuspidati Rhizoma et Radix, rats' plasma and urine samples. MIPs were successfully used to separate polydatin from the Polygoni Cuspidati Rhizoma et Radix and recovery ranged from 89.2% to 91.6%. The maximum concentration of polydatin in rats' plasma and urine samples was 2.84 ± 0.0748 µg mL^-1 and 2.64 ± 0.485 µg mL^-1, respectively. Moreover, to compare with the MIPs method, organic solvent methods were used to analyze the polydatin in rats' plasma and urine samples. The results illustrated MIPs method was effective and selective for enrichment of polydatin from the medicinal plants and biological samples.

Improvement of cerebral ischemia/reperfusion injury by daucosterol palmitate-induced neuronal apoptosis inhibition via PI3K/Akt/mTOR signaling pathway

Traditional Chinese medicine has growing importance in the treatment of ischemia stroke due to its abundance and low drug resistance. In this study, we aim to investigate the therapeutic potential of daucosterol palmitate against ischemia stroke, as well as its neuro-protective mechanism. The dose-response effects of daucosterol palmitate in the protection from brain damage were evaluated in a cerebral ischemia/reperfusion (I/R) rat model. The correlation of neuro-protective effects of daucosterol palmitate with apoptosis inhibition was examined and the possible signaling targets were identified. Our findings revealed that daucosterol palmitate treatment after 2 h' ischemia significantly lowered brain damage, and neuronal cell apoptosis caused by I/R injury in a dose-response mode (20, 40 and 80 mg/kg). Western blot analysis indicated that daucosterol palmitate could reverse the effects of I/R injury on protein expression of PI3K and mTOR, and phosphorylation of Akt. Contrarily, inactivation of PI3K using wortmannin dramatically antagonized the effect of daucosterol palmitate for I/R injury. With these findings, it supports the application potential of daucosterol palmitate in the treatment of ischemia stroke. Besides, the PI3K/Akt/mTOR pathway might be potential cellular targets for daucosterol palmitate.

Dimeric Diarylheptanoids with Neuroprotective Activities from Rhizomes of Alpinia officinarum

Two novel dimeric diarylheptanoids, alpinidinoids A [(±)-1] and B (2), with two unusual coupling patterns, together with a new naturally occurring diarylheptanoid dimer possessing a rare pyridine ring linkage (alpinidinoid C, 3), were isolated from the rhizomes of Alpinia officinarum. Their structures including absolute configurations were determined by extensive spectroscopic methods and theoretical calculations. All isolates were examined for their neuroprotective activities against oxygen-glucose deprivation and reoxygenation (OGD/R) damage in primary cortical neurons. Remarkably, the dextrorotatory enantiomer of alpinidinoid A [(+)-1] significantly ameliorated OGD/R-induced neuronal apoptosis, which was dependent on the activation of the AKT/mTOR signaling pathway.

The Beneficial Effects of Raffinee in Permanent Occulted Stroke Mice

Ischemic stroke is a major cause of disability and mortality globally. Although thrombolytic therapy is routinely adopted in cases of ischemic stroke, various alternative natural neuroprotectants are also used as effective adjuvant therapies to recover neurofunction following ischemic stroke. Raffinee, a natural fermented product with strong antioxidant and neuroprotective activities, has antiatherogenic effects in animals and has exhibited neuroprotective effects in a clinical trial by recovering motor and sensory function following spinal cord lesion. This study reveals the advantageous effects of Raffinee on PC12 cells by decreasing hypoxia-induced apoptosis in mice with permanent middle cerebral artery occlusion (pMCAO) by increasing the levels of neurotrophic factors such as S100β, reducing serum inflammatory factors such as matrix metalloproteinases (MMP)-9/MMP-2 ratio, tumor necrosis factor-α, and interleukin (IL)-6 level, and increasing IL-10 levels. Significantly reduced brain infarct volume along with a favorable survival ratio was observed for pMCAO mice that received Raffinee, suggesting a neuroprotective potential of Raffinee in cases of acute ischemic stroke by suppressing apoptosis.

SIRT1-regulated HMGB1 release is partially involved in TLR4 signal transduction: A possible anti-neuroinflammatory mechanism of resveratrol in neonatal hypoxic-ischemic brain injury

Neonatal hypoxic-ischemic brain injury (HIBI) is a knotty disease that lacks appropriate treatment. Inflammation is an important contributor to brain damage, and microglia are responsible for eliciting early and pronounced inflammatory reactions in the immature brain after hypoxic-ischemic (HI) insult. Acetylated HMGB1 can be released from immune cells into the extracellular space, where it acts as a danger-associated molecular pattern molecule to activate TLR4 signalling-mediated inflammatory responses. Resveratrol has neuroprotective and anti-inflammatory effects against HIBI, but whether these effects involve the regulation of the TLR4 signalling pathway and whether HMGB1 participates in this process is still unclear. We investigated the anti-inflammatory effects of resveratrol in HIBI and the molecular mechanisms potentially involved in the effect. The in vivo and in vitro results indicated that the level of cytoplasmic HMGB1 in microglia increased after insult and that treating experimental animals or mouse BV2 microglial cells with resveratrol attenuated HI insult-induced neuroinflammation, which was characterized by improved behavioural defects, reduced microglial activation and TLR4/MyD88/NF-κB signalling, and attenuated primary neuronal damage; this was accompanied by the inhibition of HMGB1 nucleoplasmic transfer and extracellular release. EX527 pretreatment reversed these effects. In addition, co-immunoprecipitation confirmed that SIRT1 was directly involved in the HMGB1 acetylation process in BV2 cells after oxygen glucose deprivation. These data demonstrate that resveratrol plays a neuroprotective role in neonatal HIBI by activating SIRT1 to inhibit HMGB1/TLR4/MyD88/NF-κB signalling and subsequent neuroinflammatory responses.

The Role of Mast Cells in Stroke

Mast cells (MCs) are densely granulated perivascular resident cells of hematopoietic origin. Through the release of preformed mediators stored in their granules and newly synthesized molecules, they are able to initiate, modulate, and prolong the immune response upon activation. Their presence in the central nervous system (CNS) has been documented for more than a century. Over the years, MCs have been associated with various neuroinflammatory conditions of CNS, including stroke. They can exacerbate CNS damage in models of ischemic and hemorrhagic stroke by amplifying the inflammatory responses and promoting brain–blood barrier disruption, brain edema, extravasation, and hemorrhage. Here, we review the role of these peculiar cells in the pathophysiology of stroke, in both immature and adult brain. Further, we discuss the role of MCs as potential targets for the treatment of stroke and the compounds potentially active as MCs modulators.