Resveratrol for Alzheimer's disease

Stilbenoids isolated from the roots of Rheum lhasaense under the guidance of the acetylcholinesterase inhibition activity

Four unknown stilbenoids, including one dimer, namely 4'-methoxy-scirpusin A (5) and three monomeric stilbene glycosides, namely piceatannol-3'-O-[2''-(3,5-dihydroxy-4-methoxybenzoyl)]-β-D-glucopyranoside (13), piceatannol-3'-O-(2''-galloyl)-β-D-glucopyranoside (14) and piceatannol-3'-O-(6″-p-coumaroyl)-β-D-glucopyranoside (16) together with 15 described compounds, were isolated from the ethyl acetate fraction of the ethanol extract of roots of Rheum lhasaense based on the guidance of the inhibitory effect on acetylcholinesterase. The structures of the unknown compounds were established by combined spectroscopic analysis and comparing their spectral data with compounds with similar structures. Some selected components were also investigated for their inhibitory abilities on acetylcholinesterase (AChE), indicating that compound 13 may be responsible for higher inhibitory activity of the ethyl acetate fraction on AChE.

Resveratrol noncompetitively inhibits glycine receptor-mediated currents in neurons of rat central auditory neurons

Resveratrol, a naturally occurring stilbene found in red wine, is known to modulate the activity of several types of ion channels and membrane receptors, including Ca²⁺, K⁺, and Na⁺ ion channels. However, little is known about the effects of resveratrol on some important receptors, such as glycine receptors and GABA_A receptors, in the central nervous system (CNS). In the present study, the effects of resveratrol on glycine receptor or GABA_A receptor-mediated currents in cultured rat inferior colliculus (IC) and auditory cortex (AC) neurons were studied using whole-cell voltage-clamp recordings. Resveratrol itself did not evoke any currents in IC neurons but it reversibly decreased the amplitude of glycine-induced current (I_Gly) in a concentration-dependent manner. Resveratrol did not change the reversal potential of I_Gly but it shifted the concentration-response relationship to the right without changing the Hill coefficient and with decreasing the maximum response of I_Gly. Interestingly, resveratrol inhibited the amplitude of I_Gly but not that of GABA-induced current (I_GABA) in AC neurons. More importantly, resveratrol inhibited GlyR-mediated but not GABA_AR-mediated inhibitory postsynaptic currents in IC neurons using brain slice recordings. Together, these results demonstrate that resveratrol noncompetitively inhibits I_Gly in auditory neurons by decreasing the affinity of glycine to its receptor. These findings suggest that the native glycine receptors but not GABA_A receptors in central neurons are targets of resveratrol during clinical administrations.

The Potential Roles of Redox Enzymes in Alzheimer's Disease: Focus on Thioredoxin

Alzheimer's disease (AD) is the most common neurodegenerative diseases. Increasing studies have demonstrated the critical importance for redox proteins mediating neuronal protection in models of AD. This review briefly describes some of the risk factors contributing to AD, specifically highlighting the important roles of oxidative stress in the pathology of AD. Then this article concisely introduces the dysregulation and functions of two main redox enzymes, peroxiredoxins and glutaredoxins, in AD models. This review emphasizes the neuroprotective role of the third redox enzyme thioredoxin (Trx), an important multifunctional protein regulating cellular redox status. This commentary not only summarizes the alterations of Trx expression in AD patients and models, but also reviews the potential effects and mechanisms of Trx, Trx-related molecules and Trx-inducing compounds against AD. In conclusion, Trx has a potential neuroprotection in AD and may be very promising for clinical therapy of AD in the future.

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.

Alzheimer's Disease: An Overview of Major Hypotheses and Therapeutic Options in Nanotechnology

Alzheimer's disease (AD), a progressively fatal neurodegenerative disorder, is the most prominent form of dementia found today. Patients suffering from Alzheimer's begin to show the signs and symptoms, like decline in memory and cognition, long after the cellular damage has been initiated in their brain. There are several hypothesis for the neurodegeneration process; however, the lack of availability of in vivo models makes the recapitulation of AD in humans impossible. Moreover, the drugs currently available in the market serve to alleviate the symptoms and there is no cure for the disease. There have been two major hurdles in the process of finding the same-the inefficiency in cracking the complexity of the disease pathogenesis and the inefficiency in delivery of drugs targeted for AD. This review discusses the different drugs that have been designed over the recent years and the drug delivery options in the field of nanotechnology that have been found most feasible in surpassing the blood-brain barrier (BBB) and reaching the brain.

Recent efforts in drug discovery on vascular inflammation and consequent atherosclerosis

Introduction: Preservation of vascular endothelium integrity and maintenance of its full functionality are fundamental aspects in order to avoid both cardiovascular and non-cardiovascular diseases.Areas covered: Although a massive endothelial disruption is a rare condition, caused by acute and uncontrolled inflammatory responses (e.g. the cytokine storm induced by SARS-CoV-2 infection), more frequently the vascular tree is the first target of slowly progressive inflammatory processes which affect the integrity of endothelium and its 'barrier' function, supporting the onset of atherosclerotic plaque and spreading inflammation. This endothelial dysfunction leads to decrease NO biosynthesis, impaired regulation of vascular tone, and increased platelet aggregation. Such chronic subclinic inflammation leads to macrophage infiltration in atherosclerotic lesions. Therefore, many efforts should be addressed to find useful approaches to preserve vascular endothelium from inflammation. In this review, the authors have evaluated the most recent strategies to counteract this pathological condition.Expert opinion: The therapeutic and nutraceutical approaches represent useful tools to treat or prevent different phases of vascular inflammation. In particular, the pharmacological approach should be used in advanced phases characterized by clinical signs of vascular disease, whilst the nutraceutical approach may represent a promising preventive strategy to preserve the integrity of the endothelial tissue.

The Molecular Mechanisms of Action of Photobiomodulation Against Neurodegenerative Diseases: A Systematic Review

Neurodegenerative diseases might be slow but relentless, as we continue to fail in treating or delaying their progression. Given the complexity in the pathogenesis of these diseases, a broad-acting approach like photobiomodulation can prove promising. Photobiomodulation (PBM) uses red and infrared light for therapeutic benefits, working by stimulating growth and proliferation. The implications of photobiomodulation have been studied in several neurodegenerative disease models. It has been shown to improve cell survival, decrease apoptosis, alleviate oxidative stress, suppress inflammation, and rescue mitochondrial function. In in vivo models, it has reportedly preserved motor and cognitive skills. Beyond mitochondrial stimulation, the molecular mechanisms by which photobiomodulation protects against neurodegeneration have not been very well studied. This review has systematically been undertaken to study the effects of photobiomodulation at a molecular level and identify the different biochemical pathways and molecular changes in the process. The data showed the involvement of pathways like extracellular signal-regulated kinase (ERK), mitogen-activated protein kinase (MAPK), and protein kinase B (Akt). In addition, the expression of several genes and proteins playing different roles in the disease mechanisms was found to be influenced by PBM, such as neurotrophic factors and secretases. Studying the literature indicated that PBM can be translated to a potential therapeutic tool, acting through a spectrum of mechanisms that work together to decelerate disease progression in the organism, which is difficult to achieve through pharmacological interventions.

Immunotoxicity studies of trans-resveratrol in male B6C3F1/N mice

Resveratrol is a naturally occurring polyphenol that is being investigated to treat and prevent various diseases, both experimentally and in the clinic. Despite increased use and interest in resveratrol due to its immunomodulatory properties, there is a lack of studies evaluating potential toxicities, particularly immunotoxicity, associated with resveratrol use. A previous 2-week study found decreasing thymus weight in male B6C3F1/N mice with increasing exposure to trans-resveratrol. This study is a follow-up on those findings by evaluating immune function. Male adult B6C3F1/N mice were given trans-resveratrol (0, 156, 312, 625, 1250, 2500 mg/kg/day) via oral gavage for 28 days and functional immune tests and histopathology were evaluated. There were no treatment-related effects on body weight during the study. Humoral, cell-mediated, and innate immune function were not altered after 28 days of trans-resveratrol treatment. There were also no changes in organ weight or microscopic alterations in immune organs. Overall, under the conditions of this study, there was no evidence of immunotoxicity or improvements in immune function associated with oral exposure to trans-resveratrol in male mice. Importantly, the immunomodulatory benefits of resveratrol may require a prerequisite level of inflammatory activity and may not be observable in healthy individuals.

SIRT1 Inhibits High Shear Stress-Induced Apoptosis in Rat Cortical Neurons

INTRODUCTION

Sirtuin1 (SIRT1), one of NAD+-dependent protein deacetylases, is proved to be neuroprotective in aging diseases, but its effect on neuronal apoptosis has not been clarified. To investigate the role of SIRT1 in inhibiting neuronal apoptosis, SIRT1 was interfered or overexpressed in cortical neurons.

METHODS

We exerted overloading laminar shear stress with 10 dyn/cm2 for 4, 8, and 12 h on neurons to cause cortical neuronal apoptosis, and the apoptosis percentage was tested by TUNEL assay. The adenovirus plasmids containing SIRT1 RNA interference or SIRT1 wild type gene were transfected into neurons before shear stress loading. SIRT1 mRNA and protein level were tested by Real-time PCR, immunofluorescence and western blots assay.

RESULTS

SIRT1 was primarily expressed in nucleus of cortical neurons, and its mRNA level was significantly increased after 4 h stimulation. SIRT1 RNAi cortical neurons had higher TUNEL positive cells, while SIRT1 overexpression significantly decreased the percentage of died cells induced by shear stress compared to control group.

CONCLUSIONS

SIRT1 plays a neuroprotective role in shear stress induced apoptosis and could be as potential pharmacological targets against neuronal degeneration in future.

Hypoxia-Inducible Factor-1: A Potential Target to Treat Acute Lung Injury

Acute lung injury (ALI) is an acute hypoxic respiratory insufficiency caused by various intra- and extrapulmonary injury factors. Presently, excessive inflammation in the lung and the apoptosis of alveolar epithelial cells are considered to be the key factors in the pathogenesis of ALI. Hypoxia-inducible factor-1 (HIF-1) is an oxygen-dependent conversion activator that is closely related to the activity of reactive oxygen species (ROS). HIF-1 has been shown to play an important role in ALI and can be used as a potential therapeutic target for ALI. This manuscript will introduce the progress of HIF-1 in ALI and explore the feasibility of applying inhibitors of HIF-1 to ALI, which brings hope for the treatment of ALI.

Lipid Peroxidation and Antioxidant Supplementation in Neurodegenerative Diseases: A Review of Human Studies

Being characterized by progressive and severe damage in neuronal cells, neurodegenerative diseases (NDDs) are the major cause of disability and morbidity in the elderly, imposing a significant economic and social burden. As major components of the central nervous system, lipids play important roles in neural health and pathology. Disturbed lipid metabolism, particularly lipid peroxidation (LPO), is associated with the development of many NDDs, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS), all of which show elevated levels of LPO products and LPO-modified proteins. Thus, the inhibition of neuronal oxidation might slow the progression and reduce the severity of NDD; natural antioxidants, such as polyphenols and antioxidant vitamins, seem to be the most promising agents. Here, we summarize current literature data that were derived from human studies on the effect of natural polyphenols and vitamins A, C, and E supplementation in patients with AD, PD, and ALS. Although these compounds may reduce the severity and slow the progression of NDD, research gaps remain in antioxidants supplementation in AD, PD, and ALS patients, which indicates that further human studies applying antioxidant supplementation in different forms of NDDs are urgently needed.

The potential role of nutritional components in improving brain function among patients with Alzheimers disease: a meta-analysis of RCT studies

OBJECTIVE

To find out the potential role of nutritional components in improving brain function among patients with Alzheimer`s disease (AD).

METHODS

The correlation between nutrition and cerebral function in cases of AD has been the focus of 19 prospective randomised controlled trials (RCTs) with a combined research sample of 2297 patients. These RCTs are subject to systematic review and meta-analysis in the current paper RESULTS: Findings showed that chain-free secondary saturated fatty acids (SFA) and trans fatty acids (TFA) occurred in higher concentrations in AD patients` brains than in controls. Furthermore, neuroinflammation was caused by remodelling of the lipid membrane and AD patients` cognitive function was impacted by alterations in tyrosine, tryptophan, purine, and tocopherol pathway metabolomics. Moreover, in cases of mild-to-moderate AD, reduction in functionality was induced by administration of alpha-tocopherol for more than 12 months. Consumption of Souvenaid helps in synaptic synthesis, which enhances functional connectivity. Furthermore, consumption of the B vitamins folate, cobalamin and pyridoxine at dosages of 0.8 mg, 0.5 mg and 20 mg per day, respectively, over a period of one year resulted in lower plasma tHcy levels and brain atrophy.

CONCLUSION

Chain-free SFA and TFA occur in greater amounts in the brains of individuals with AD than in those without AD.

Transcription factor NRF2 as a promising therapeutic target for Alzheimer's disease

Oxidative stress is considered as one of the pathogenesis of Alzheimer's disease (AD) and plays an important role in the occurrence and development of AD. Nuclear factor erythroid 2 related factor 2 (NRF2) is a key regulatory of oxidative stress defence. There is growing evidence indicating the relationship between NRF2 and AD. NRF2 activation mitigates multiple pathogenic processes involved in AD by upregulating antioxidative defense, inhibiting neuroinflammation, improving mitochondrial function, maintaining proteostasis, and inhibiting ferroptosis. In addition, several NRF2 activators are currently being evaluated as AD therapeutic agents in clinical trials. Thus, targeting NRF2 has been the focus of a new strategy for prevention and treatment of AD. In this review, the role of NRF2 in AD and the NRF2 activators advanced into clinical and preclinical studies will be summarized.

Potential Drug Candidates to Treat TRPC6 Channel Deficiencies in the Pathophysiology of Alzheimer's Disease and Brain Ischemia

Alzheimer’s disease and cerebral ischemia are among the many causative neurodegenerative diseases that lead to disabilities in the middle-aged and elderly population. There are no effective disease-preventing therapies for these pathologies. Recent in vitro and in vivo studies have revealed the TRPC6 channel to be a promising molecular target for the development of neuroprotective agents. TRPC6 channel is a non-selective cation plasma membrane channel that is permeable to Ca²⁺. Its Ca²⁺-dependent pharmacological effect is associated with the stabilization and protection of excitatory synapses. Downregulation as well as upregulation of TRPC6 channel functions have been observed in Alzheimer’s disease and brain ischemia models. Thus, in order to protect neurons from Alzheimer’s disease and cerebral ischemia, proper TRPC6 channels modulators have to be used. TRPC6 channels modulators are an emerging research field. New chemical structures modulating the activity of TRPC6 channels are being currently discovered. The recent publication of the cryo-EM structure of TRPC6 channels should speed up the discovery process even more. This review summarizes the currently available information about potential drug candidates that may be used as basic structures to develop selective, highly potent TRPC6 channel modulators to treat neurodegenerative disorders, such as Alzheimer’s disease and cerebral ischemia.

Health-promoting role of dietary bioactive compounds through epigenetic modulations: a novel prophylactic and therapeutic approach

The epigenome is an overall epigenetic state of an organism, which is as important as that of the genome for normal development and functioning of an individual. Epigenetics involves heritable but reversible changes in gene expression through alterations in DNA methylation, histone modifications and regulation of non-coding RNAs in cells, without any change in the DNA sequence. Epigenetic changes are owned by various environmental factors including pollution, microbiota and diet, which have profound effects on epigenetic modifiers. The bioactive compounds present in the diet mainly include curcumin, resveratrol, catechins, quercetin, genistein, sulforaphane, epigallocatechin-3-gallate, alkaloids, vitamins, and peptides. Bioactive compounds released during fermentation by the action of microbes also have a significant effect on the host epigenome. Besides, recent studies have explored the new insights in vitamin's functions through epigenetic regulation. These bioactive compounds exert synergistic, preventive and therapeutic effects when combined as well as when used with chemotherapeutic agents. Therefore, these compounds have potential of therapeutic agents that could be used as "Epidrug" to treat many inflammatory diseases and various cancers where chemotherapy results have many side effects. In this review, the effect of diet derived bioactive compounds through epigenetic modulations on in vitro and in vivo models is discussed.

Resveratrol Rescues Tau-Induced Cognitive Deficits and Neuropathology in a Mouse Model of Tauopathy

BACKGROUND

Alzheimer's Disease (AD) is characterized by the presence of extracellular amyloid-β (Aβ) plaques and intraneuronal neurofibrillary tangles assembled by the microtubuleassociated protein tau. Increasing evidence demonstrated that tau pathology played an important role in AD progression. Resveratrol (RSV) has previously proved to exert neuroprotective effect against AD by inhibiting Aβ generation and Aβ-induced neurocytotoxicity, while its effect on tau pathology is still unknown.

METHODS

The effect of RSV on tau aggregation was measured by Thioflavin T fluorescence and Transmission electron microscope imaging. The effect of RSV on tau oligomer-induced cytotoxicity was assessed by MTT assay and the uptake of extracellular tau by N2a cells was determined by immunocytochemistry. 6-month-old male PS19 mice were treated with RSV or vehicle by oral administration (gavage) once a day for 5 weeks. The cognitive performance was determined using Morris water maze test, object recognition test and Y-maze test. The levels of phosphorylated-tau, gliosis, proinflammatory cytokines such as TNF-α and IL-1β, and synaptic proteins including synaptophysin and PSD95 in the brains of the mice were evaluated by immunoblotting, immunostaining and ELISA, respectively.

RESULTS

RSV significantly inhibited tau aggregation and tau oligomer-induced cytotoxicity, and blocked the uptake of extracellular tau oligomers by N2a cells. When applied to PS19 mice, RSV treatment effectively rescued cognitive deficits, reducing the levels of phosphorylated tau, neuroinflammation and synapse loss in the brains of mice.

CONCLUSION

These findings suggest that RSV has promising therapeutic potential for AD and other tauopathies.

Neuroprotective Effects of Chronic Resveratrol Treatment and Exercise Training in the 3xTg-AD Mouse Model of Alzheimer's Disease

To date, there is no cure or effective treatment for Alzheimer’s disease (AD), a chronic neurodegenerative condition that affects memory, language, and behavior. AD is characterized by neuroinflammation, accumulation of brain amyloid-beta (Aβ) oligomers and neurofibrillary tangles, increased neuronal apoptosis, and loss of synaptic function. Promoting regular exercise and a diet containing polyphenols are effective non-pharmacological approaches that prevent the progression of neurodegenerative diseases. In this study, we measured various conformational toxic species of Aβ and markers of inflammation, apoptosis, endolysosomal degradation, and neuroprotection after 5 months of exercise training (ET), resveratrol (Resv) treatment, or combination treatment in the 3xTg-AD mouse model of AD. Our main results indicate that Resv decreased neuroinflammation and accumulation of Aβ oligomers, increased levels of neurotrophins, synaptic markers, silent information regulator, and decreased markers of apoptosis, autophagy, endolysosomal degradation and ubiquitination in the brains of 3xTg-AD mice. ET improved some markers related to neuroprotection, but when combined with Resv treatment, the benefits achieved were as effective as Resv treatment alone. Our results show that the neuroprotective effects of Resv, ET or Resv and ET are associated with reduced toxicity of Aβ oligomers, suppression of neuronal autophagy, decreased apoptosis, and upregulation of key growth-related proteins.

Sirtuins as Possible Predictors of Aging and Alzheimer's Disease Development: Verification in the Hippocampus and Saliva

Verification of signaling molecules in the saliva is a non-invasive method of diagnosis and evaluation of treatment effectiveness in different pathologies. Sirtuins (SIRT), proteins from NAD-dependent histone deacetylases, are supposed to be involved in the pathogenesis of Alzheimerэs disease. Age-related decrease in sirtuins expression induces many pathophysiological processes that could lead to neurodegeneration. We studied the expression of SIRT1, SIRT3, SIRT5, and SIRT6 in the hippocampus and saliva of humans without neurological pathologies and in patients with Alzheimer's disease of elderly and senile age. In elderly and senile patients, the expression of SIRT1, SIRT3, and SIRT6 in the hippocampus and saliva was 1.5-4.9-fold reduced in comparison with healthy individuals of the corresponding age. In healthy senile persons, the expression of SIRT6 in the hippocampus and saliva was 2.5-4.5-fold lower than in healthy elderly individuals. Measurement of SIRT1, SIRT3, and SIRT6 concentration in the saliva can be used as an additional method for intravital non-invasive diagnosis of Alzheimer's disease in patients of advanced age. SIRT6 concentration in the saliva can be recommended as a marker for assessment of the rate of aging.

Current Evidence on the Effect of Dietary Polyphenols Intake on Brain Health

Background:

In recent years, the possibility of favorably influencing the cognitive capacity through the promotion of lifestyle modifications has been increasingly investigated. In particular, the relationship between nutritional habits and brain health has attracted special attention. Polyphenols are secondary metabolites of plants. These phytochemicals are present in vegetables, fruits, legumes, olive oil, nuts. They include several antioxidant compounds and are generally considered to be involved in defense against chronic human diseases. In recent years, there has been a growing scientific interest in their potential health benefits to the brain.

Objective:

In this mini-review, we focus on the current evidence defining the position of polyphenols dietary intake in the prevention/slowdown of human neurodegenerative diseases.

Methods:

A literature research was performed using the keywords “polyphenols”, “brain”, “nutrition”, individually or all together, focusing on human trials.

Results:

The available clinical studies on the effect of polyphenols on cognitive functions are quite convincing. Regular dietary intake of polyphenols would seem to reduce the risk of neurodegenerative diseases. Moreover, beyond their beneficial power on the central nervous system, these phytochemicals seem also to be able to work on numerous cellular targets. They show different biological actions, that however, have to be confirmed in long-term randomized clinical trials. Currently, most data propose that a combination of phytonutrients instead of any single polyphenol is responsible for health benefits.

Conclusions:

Evolving indications suggest that dietary polyphenols may exercise beneficial actions on the central nervous system, thus representing a possible tool to preserve cognitive performance. Key questions to improve the coherence and reproducibility in the development of polyphenols as a possible future therapeutic drug require a better understanding of the sources of polyphenols, their treatment and more standardized tests including bioavailability of bioactive metabolites and studies of permeability of the brain.

Resveratrol suppresses insulin-like growth factor I-induced osteoblast migration: attenuation of the p44/p42 MAP kinase pathway

Resveratrol is a natural polyphenol with beneficial antioxidant properties. It suppresses the migration of osteoblast-like MC3T3-E1 cells induced by epidermal growth factor, via SIRT1-mediated inhibition of SAPK/JNK and Akt. Moreover, insulin-like growth factor-I (IGF-I) stimulates the migration involving the pathways of p44/p42 mitogen-activated protein (MAP) kinase and Akt. Therefore, we investigated the effects of resveratrol on IGF-I-induced cell migration. Resveratrol and SRT1720, an activator of SIRT1, suppressed IGF-I-induced migration. Inauhzin, a SIRT1 inhibitor, significantly rescued the inhibition of IGF-I-induced cell migration by resveratrol. Resveratrol inhibited IGF-I-induced phosphorylation of p44/p42 MAP kinase but not Akt. SRT1720 inhibited IGF-I-induced phosphorylation of p44/p42 MAP kinase. Furthermore, PD98059, p44/p42 MAP kinase inhibitor, alone suppressed IGF-I-induced osteoblast migration, but did not affect the suppressive effect of resveratrol when administered concomitantly. These findings strongly suggest that resveratrol suppresses IGF-I-induced osteoblast migration via SIRT1 activation at least partially by attenuating the p44/p42 MAP kinase pathway.

Antioxidant Modulation of mTOR and Sirtuin Pathways in Age-Related Neurodegenerative Diseases

In the human body, cell division and metabolism are expected to transpire uneventfully for approximately 25 years. Then, secondary metabolism and cell damage products accumulate, and ageing phenotypes are acquired, causing the progression of disease. Among these age-related diseases, neurodegenerative diseases have attracted considerable attention because of their irreversibility, the absence of effective treatment and their relationship with social and economic pressures. Mechanistic (formerly mammalian) target of rapamycin (mTOR), sirtuin (SIRT) and insulin/insulin growth factor 1 (IGF1) signalling pathways are among the most important pathways in ageing-associated conditions, such as neurodegeneration. These longevity-related pathways are associated with a diversity of various processes, including metabolism, cognition, stress reaction and brain plasticity. In this review, we discuss the roles of sirtuin and mTOR in ageing and neurodegeneration, with an emphasis on their regulation of autophagy, apoptosis and mitochondrial energy metabolism. The intervention of neurodegeneration using potential antioxidants, including vitamins, phytochemicals, resveratrol, herbals, curcumin, coenzyme Q10 and minerals, specifically aimed at retaining mitochondrial function in the treatment of Alzheimer's disease, Parkinson's disease and Huntington's disease is highlighted.

Has resveratrol a potential for mucopolysaccharidosis treatment?

Mucopolysaccharidoses (MPS) represent a devastating group of lysosomal storage diseases (LSD) affecting approximately 1 in 25,000 individuals, where degradation of glycosaminoglycans (GAG) by lysosomal enzymes is impaired due to mutations causing defects in one of GAG-degrading enzymes. The most commonly used therapy for MPS is enzyme replacement therapy, consisting of application of an active form of the missing enzyme. However, supply of the missing enzyme is not enough in case of MPS types whose symptoms are expressed in central nervous system (CNS), as enzyme does not cross the blood-brain barrier. Moreover, even though enzyme replacement therapy for non-neuronopathic MPS IVA type is approved, it has a limited impact on bone abnormalities, that are one of main symptoms in the disease. Therefore, research into alternative therapeutic approaches for these types of MPS is highly desirable. One such alternative strategy is accelerated degradation of GAG by induction of autophagy. Autophagy is a process of lysosomal degradation of macromolecules that become abnormal or unnecessary for cells. One of the latest discoveries is that GAGs can also be such molecules. Potential drug should also cross blood-brain barrier and be safe in long-term therapy. It seems that one of the polyphenols, resveratrol, can meet the requirements. The mechanism of its action in autophagy stimulation is pleiotropic. Therefore, in this review, we will briefly discuss potential of resveratrol treatment for mucopolysaccharidosis through autophagy stimulation based on research in diseases with similar outcome.

Resveratrol Inhibits Ischemia-Induced Myocardial Senescence Signals and NLRP3 Inflammasome Activation

Aims

The aim of this study was to investigate whether resveratrol (RSV) could ameliorate ischemia- and hypoxia-associated cardiomyocyte apoptosis and injury via inhibiting senescence signaling and inflammasome activation.

Materials and Methods

Mice were treated with RSV by gastric tube (320 mg/kg/day) or vehicle one week before left coronary artery ligation or sham surgery until the end of the experiments. After pressure–volume loop analysis, mouse hearts were harvested for histopathological (including PSR, TTC, TUNEL staining, immunohistochemistry, and immunofluorescence) and molecular analysis by western blotting and RT-PCR. In addition, neonatal rat cardiomyocytes (NRCMs), cardiac fibroblasts (CFs), and macrophages were isolated for in vitro experiments. Key Findings. RSV treatment decreased mortality and improved cardiac hemodynamics. RSV inhibited the expression of senescence markers (p53, p16, and p19), inflammasome markers (NLRP3 and Cas1 p20), and nuclear translocation of NF-κB, hence alleviating infarction area, fibrosis, and cell apoptosis. RSV also inhibited expression of interleukin- (IL-) 1β, IL-6, tumor necrosis factor-α, and IL-18 in vivo. In in vitro experiment, RSV prevented hypoxia-induced NRCM senescence and apoptosis. After inhibition of sirtuin 1 (Sirt1) by EX27, RSV failed to inhibit p53 acetylation and expression. Moreover, RSV could inhibit expression of NLRP3 and caspase 1 p20 in NRCMs, CFs, and macrophages, respectively, in in vitro experiments. Significance. Our findings revealed that RSV protected against ischemia-induced mouse heart injury in vivo and hypoxia-induced NRCM injury in vitro via regulating Sirt1/p53-mediated cell senescence and inhibiting NLRP3-mediated inflammasome activation.

Neuroprotection: Targeting Multiple Pathways by Naturally Occurring Phytochemicals

With the increase in the expectancy of the life span of humans, neurodegenerative diseases (NDs) have imposed a considerable burden on the family, society, and nation. In defiance of the breakthroughs in the knowledge of the pathogenesis and underlying mechanisms of various NDs, very little success has been achieved in developing effective therapies. This review draws a bead on the availability of the nutraceuticals to date for various NDs (Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, Huntington's disease, vascular cognitive impairment, Prion disease, Spinocerebellar ataxia, Spinal muscular atrophy, Frontotemporal dementia, and Pick's disease) focusing on their various mechanisms of action in various in vivo and in vitro models of NDs. This review is distinctive in its compilation to critically review preclinical and clinical studies of the maximum phytochemicals in amelioration and prevention of almost all kinds of neurodegenerative diseases and address their possible mechanism of action. PubMed, Embase, and Cochrane Library searches were used for preclinical studies, while ClinicalTrials.gov and PubMed were searched for clinical updates. The results from preclinical studies demonstrate the efficacious effects of the phytochemicals in various NDs while clinical reports showing mixed results with promise for phytochemical use as an adjunct to the conventional treatment in various NDs. These studies together suggest that phytochemicals can significantly act upon different mechanisms of disease such as oxidative stress, inflammation, apoptotic pathways, and gene regulation. However, further clinical studies are needed that should include the appropriate biomarkers of NDs and the effect of phytochemicals on them as well as targeting the appropriate population.

Protection of the Retinal Ganglion Cells: Intravitreal Injection of Resveratrol in Mouse Model of Ocular Hypertension

Purpose

To investigate the efficacy of intravitreal administration of resveratrol (RSV) in a microbead-induced high intraocular pressure (IOP) murine model for glaucoma.

Methods

Experiments were performed using adult C57BL/6JJcl mice. Polystyrene microbeads were injected into the anterior chamber to induce IOP elevation. Retinal flat-mounts and sections were assessed by immunohistochemistry to detect the expression of reactive oxygen species and acetyl-p53 in retinal ganglion cells (RGCs), brain-derived neurotrophic factor (BDNF) in Müller glial cells (MGCs), and the receptor tropomyosin receptor kinase B (TrkB) in RGCs. Light cycler real-time PCR was also used for confirming gene expression of BDNF in primary cultured MGCs exposed to RSV.

Results

Microbeads induced high IOP followed by RGC death and axon loss. Administration of RSV rescued RGCs via decreased reactive oxygen species generation and acetyl-p53 expression in RGCs and upregulated BDNF in MGCs and TrkB expression in RGCs, which exhibited a strong cytoprotective action against cell death through multiple pathways under high IOP.

Conclusions

Our data suggest that administration of RSV may delay the progress of visual dysfunction during glaucoma and may therefore have therapeutic potential.

Synthesis, biological evaluation of benzothiazole derivatives bearing a 1,3,4-oxadiazole moiety as potential anti-oxidant and anti-inflammatory agents

Twenty benzothiazole derivatives bearing a 1,3,4-oxadiazole moiety were synthesized and evaluated for their anti-oxidant and anti-inflammatory activities. Among these compounds, 8h and 8l were appeared to have high radical scavenging efficacies as 0.05 ± 0.02 and 0.07 ± 0.03 mmol/L of IC₅₀ values in ABTS⁺ bioassay, respectively. In anti-inflammatory tests, compound 8h displayed good activity with 57.35% inhibition after intraperitoneal administration, which was more potent than the reference drug (indomethacin). Molecular modeling studies were performed to investigate the binding mode of the representative compound 8h into COX-2 enzyme. In vitro enzyme study implied that compound 8h exerted its anti-inflammatory activity through COX-2 inhibition.

Resveratrol Derivatives as Potential Treatments for Alzheimer's and Parkinson's Disease

Neurodegenerative diseases are characterized by the progressive loss of neurons in different regions of the nervous system. Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the two most prevalent neurodegenerative diseases, and the symptoms associated with these pathologies are closely related to the regions that are most affected by the process of neurodegeneration. Despite their high prevalence, currently, there is no cure or disease-modifying drugs for the treatment of these conditions. In the last decades, due to the need for the development of new treatments for neurodegenerative diseases, several authors have investigated the neuroprotective actions of naturally occurring molecules, such as resveratrol. Resveratrol is a stilbene found in several plants, including grapes, blueberries, raspberries, and peanuts. Studies have shown that resveratrol presents neuroprotective actions in experimental models of AD and PD, however, its clinical application is limited due to its rapid metabolism and low bioavailability. In this context, studies have proposed that structural changes in the resveratrol molecule, including glycosylation, alkylation, halogenation, hydroxylation, methylation, and prenylation could lead to the development of derivatives with enhanced bioavailability and pharmacological activity. Therefore, this review article aims to discuss how resveratrol derivatives could represent viable molecules in the search for new drugs for the treatment of AD and PD.

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

The lack of effective Alzheimer's disease treatment is becoming a challenge for researchers and prompts numerous attempts to search for and develop better therapeutic solutions. Compounds that affect several routes of the neurodegeneration cascade leading to the development of disease are of particular interest. An example of such substances is resveratrol and its synthetic and natural derivatives, which have gained popularity in recent years and show promise as a possible new therapeutic option in the approach to Alzheimer's disease treatment. In this article, the state of the art evidence on the role of resveratrol (RSV) in neuroprotection is presented; research results are summarized and the importance of resveratrol and its derivatives in the treatment of Alzheimer's disease are underlined. It also focuses on various modifications of the resveratrol molecule that should be taken into account in the design of future research on drugs against Alzheimer's disease.

Resveratrol Promotes Tumor Microvessel Growth via Endoglin and Extracellular Signal-Regulated Kinase Signaling Pathway and Enhances the Anticancer Efficacy of Gemcitabine against Lung Cancer

The synergistic anticancer effect of gemcitabine (GEM) and resveratrol (RSVL) has been noted in certain cancer types. However, whether the same phenomenon would occur in lung cancer is unclear. Here, we uncovered the molecular mechanism by which RSVL enhances the anticancer effect of GEM against lung cancer cells both in vitro and in vivo. We established human lung adenocarcinoma HCC827 xenografts in nude mice and treated them with GEM and RSVL to detect their synergistic effect in vivo. Tumor tissue sections from nude mice were subjected to hematoxylin and eosin staining for blood vessel morphological observation, and immunohistochemistry was conducted to detect CD31-positive staining blood vessels. We also established the HCC827-human umbilical vein endothelial cell (HUVEC) co-culture model to observe the tubule network formation. Human angiogenesis antibody array was used to screen the angiogenesis-related proteins in RSVL-treated HCC827. RSVL suppressed the expression of endoglin (ENG) and increased tumor microvessel growth and blood perfusion into tumor. Co-treatment of RSVL and GEM led to more tumor growth suppression than treatment of GEM alone. Mechanistically, using the HCC827-HUVEC co-culture model, we showed that RSVL-suppressed ENG expression was accompanied with augmented levels of phosphorylated extracellular signal-regulated kinase (ERK) 1/2 and increased tubule network formation, which may explain why RSVL promoted tumor microvessel growth in vivo. RSVL promoted tumor microvessel growth via ENG and ERK and enhanced the anticancer efficacy of GEM. Our results suggest that intake of RSVL may be beneficial during lung cancer chemotherapy.

Resveratrol Preincubation Enhances the Therapeutic Efficacy of hUC-MSCs by Improving Cell Migration and Modulating Neuroinflammation Mediated by MAPK Signaling in a Mouse Model of Alzheimer's Disease

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are promising for the treatment of Alzheimer's disease (AD). However, their low rate of migration and survival in the brain limit their clinical applicability. This study is designed to improve the therapeutic potential of hUC-MSCs by preincubating them with resveratrol, a natural polyphenol capable of regulating cell destiny. Herein, we demonstrate that resveratrol preincubation enhances the migration of hUC-MSCs in vitro, as well as their survival and homing into the hippocampus of AD mice in vivo. Moreover, resveratrol-primed MSCs were better able to inhibit amyloid-β peptide (Aβ) deposition, Tau hyperphosphorylation, and oxidative stress, all while improving learning and memory. Notably, we found that hUC-MSCs inhibited neuroinflammation by reacting with astrocytes and microglial cells and suppressing mitogen-activated protein kinases (MAPKs), extracellular signal kinases (ERK), p38 kinases (p38), and c-Jun N-terminal kinases (JNK) signaling pathways in the hippocampus of AD mice. Furthermore, resveratrol pretreatment enhanced these effects. Conclusively, the current study revealed that resveratrol preconditioning protected hUC-MSCs against the hostile microenvironment characteristic of AD and enhanced their viability and homing into the brain of AD mice. The use of resveratrol-pretreated hUC-MSCs is thereby proposed to be a promising therapy for AD.

Stability testing of resveratrol and viniferin obtained from Vitis vinifera L. by various extraction methods considering the industrial viewpoint

Solid by-products generated in the winemaking process, can comprise valuable bioactive substances such as resveratrol and viniferin, which can be used in whole range of sectors including medicine, pharmacy, cosmetic industry etc. The changes in content of those stilbenes in extracts obtained by maceration and Soxhlet extraction were monitored using newly modified and validated high-performance liquid chromatography-mass spectrometry method which was proved to be accurate, reproducible, and efficient for their determination. The yields of individual bioactive compounds isolated from winery by-products are crucially dependent on the conditions of used extraction techniques. From this point of view, stability testing including light exposure, elevated temperature, and storage for longer time periods in the solution, represents the basis for optimizing conditions of extraction methods of resveratrol and trans-ε-viniferin. High temperature is beneficial for better release of thermally more stable stilbenes such as trans-resveratrol and trans-ε-viniferin but its application for prolonged time periods can be destructive. Light stress conditions cause the formation of otherwise unavailable cis-ε-viniferin by dimerization and photoisomerization of trans- stilbenes.

Schisandra Extract and Ascorbic Acid Synergistically Enhance Cognition in Mice Through Modulation of Mitochondrial Respiration

Cognitive decline is observed in aging and neurodegenerative diseases, including Alzheimer’s disease (AD) and dementia. Intracellular energy produced via mitochondrial respiration is used in the regulation of synaptic plasticity and structure, including dendritic spine length and density, as well as for the release of neurotrophic factors involved in learning and memory. To date, a few synthetic agents for improving mitochondrial function have been developed for overcoming cognitive impairment. However, no natural compounds that modulate synaptic plasticity by directly targeting mitochondria have been developed. Here, we demonstrate that a mixture of Schisandra chinensis extract (SCE) and ascorbic acid (AA) improved cognitive function and induced synaptic plasticity-regulating proteins by enhancing mitochondrial respiration. Treatment of embryonic mouse hippocampal mHippoE-14 cells with a 4:1 mixture of SCE and AA increased basal oxygen consumption rate. We found that mice injected with the SCE-AA mixture showed enhanced learning and memory and recognition ability. We further observed that injection of the SCE-AA mixture in mice significantly increased expression of postsynaptic density protein 95 (PSD95), an increase that was correlated with enhanced brain-derived neurotrophic factor (BDNF) expression. These results demonstrate that a mixture of SCE and AA improves mitochondrial function and memory, suggesting that this natural compound mixture could be used to alleviate AD and aging-associated memory decline.

Nasal timosaponin BII dually sensitive in situ hydrogels for the prevention of Alzheimer's disease induced by lipopolysaccharides

Alzheimer's disease (AD) is a common and severe brain disease with a high mortality among the elders, but no highly efficient medications are currently available. For example, timosaponin BII, an efficient anti-AD agent, has low oral bioavailability. Here, timosaponin BII was formulated in a temperature/ion-sensitive in situ hydrogel (ISG) that was well transformed into gels in the nasal environment. Timosaponin BII protected the PC12 cells injured by lipopolysaccharides (LPS) by decreasing TNF-α and IL-1β and stabilizing F-actin. Timosaponin BII ISGs were intranasally administered to the mice every day for 38 days. On Day 36, LPS was injected to the mice to establish an AD model. Morris water maze experiments showed that the number of the animals that were able to cross the platform returned to normal and the total distance over which the animals moved in the open field also increased, which demonstrated that the spatial memory and spontaneous behavior were improved after treatment compared to the model. Moreover, an AD improver, inducible nitric oxide synthase (iNOS) in the brain, was reduced after treatment. High brain targeting effect of timosaponin BII ISGs was confirmed by in vivo fluorescence imaging. The nasal timosaponin BII dually sensitive ISGs can serve as a promising medication for local prevention of AD.

The Plant-Derived Compound Resveratrol in Brain Cancer: A Review

Despite intensive research, malignant brain tumors are among the most difficult to treat due to high resistance to conventional therapeutic approaches. High-grade malignant gliomas, including glioblastoma and anaplastic astrocytoma, are among the most devastating and rapidly growing cancers. Despite the ability of standard treatment agents to achieve therapeutic concentrations in the brain, malignant gliomas are often resistant to alkylating agents. Resveratrol is a plant polyphenol occurring in nuts, berries, grapes, and red wine. Resveratrol crosses the blood‒brain barrier and may influence the central nervous system. Moreover, it influences the enzyme isocitrate dehydrogenase and, more importantly, the resistance to standard treatment via various mechanisms, such as O6-methylguanine methyltransferase. This review summarizes the anticancer effects of resveratrol in various types of brain cancer. Several in vitro and in vivo studies have presented promising results; however, further clinical research is necessary to prove the therapeutic efficacy of resveratrol in brain cancer treatment.

Improving Effects of Hop-Derived Bitter Acids in Beer on Cognitive Functions: A New Strategy for Vagus Nerve Stimulation

Dementia and cognitive decline are global public health problems. Moderate consumption of alcoholic beverages reduces the risk of dementia and cognitive decline. For instance, resveratrol, a polyphenolic compound found in red wine, has been well studied and reported to prevent dementia and cognitive decline. However, the effects of specific beer constituents on cognitive function have not been investigated in as much detail. In the present review, we discuss the latest reports on the effects and underlying mechanisms of hop-derived bitter acids found in beer. Iso-α-acids (IAAs), the main bitter components of beer, enhance hippocampus-dependent memory and prefrontal cortex-associated cognitive function via dopamine neurotransmission activation. Matured hop bitter acids (MHBAs), oxidized components with β-carbonyl moieties derived from aged hops, also enhance memory functions via norepinephrine neurotransmission-mediated mechanisms. Furthermore, the effects of both IAAs and MHBAs are attenuated by vagotomy, suggesting that these bitter acids enhance cognitive function via vagus nerve stimulation. Moreover, supplementation with IAAs attenuates neuroinflammation and cognitive impairments in various rodent models of neurodegeneration including Alzheimer's disease. Daily supplementation with hop-derived bitter acids (e.g., 35 mg/day of MHBAs) may be a safe and effective strategy to stimulate the vagus nerve and thus enhance cognitive function.

Lifestyle Modifications and Nutritional Interventions in Aging-Associated Cognitive Decline and Alzheimer's Disease

Alzheimer's disease (AD) is a type of incurable neurodegenerative disease that is characterized by the accumulation of amyloid-β (Aβ; plaques) and tau hyperphosphorylation as neurofibrillary tangles (NFTs) in the brain followed by neuronal death, cognitive decline, and memory loss. The high prevalence of AD in the developed world has become a major public health challenge associated with social and economic burdens on individuals and society. Due to there being limited options for early diagnosis and determining the exact pathophysiology of AD, finding effective therapeutic strategies has become a great challenge. Several possible risk factors associated with AD pathology have been identified; however, their roles are still inconclusive. Recent clinical trials of the drugs targeting Aβ and tau have failed to find a cure for the AD pathology. Therefore, effective preventive strategies should be followed to reduce the exponential increase in the prevalence of cognitive decline and dementia, especially AD. Although the search for new therapeutic targets is a great challenge for the scientific community, the roles of lifestyle interventions and nutraceuticals in the prevention of many metabolic and neurodegenerative diseases are highly appreciated in the literature. In this article, we summarize the molecular mechanisms involved in AD pathology and the possible ameliorative action of lifestyle and nutritional interventions including diet, exercise, Calorie restriction (CR), and various bioactive compounds on cognitive decline and dementia. This article will provide insights into the role of non-pharmacologic interventions in the modulation of AD pathology, which may offer the benefit of improving quality of life by reducing cognitive decline and incident AD.

D-Ribose-L-cysteine attenuates lipopolysaccharide-induced memory deficits through inhibition of oxidative stress, release of proinflammatory cytokines, and nuclear factor-kappa B expression in mice

D-Ribose-L-cysteine (DRLC), an analog of cysteine that boosts glutathione (GSH) content, has been reported to mitigate oxidative stress-mediated diseases. This study seeks to evaluate the effects of DRLC on memory deficits and the biochemical and histo-morphological changes induced by lipopolysaccharide (LPS) in mice. Male Swiss mice (n = 10) were pre-treated orally with three doses of DRLC (25 mg/kg, 50 mg/kg, and 100 mg/kg), donepezil (1 mg/kg), or vehicle (saline) for 30 min prior to the intraperitoneal injection of LPS (0.25 mg/kg) daily for 7 days. Memory functions were evaluated using the Y-maze, object recognition, and social recognition tests. The specific brain regions (prefrontal cortex and hippocampus) were evaluated to determine oxidative stress biomarkers (malondialdehyde, GSH, and catalase), acetyl-cholinesterase activity, proinflammatory cytokines (tumor necrosis factor-α and interleukin-6), expression of nuclear factor-kappa B (NF-κB), and neuronal cell morphology. DRLC (25-100 mg/kg) reversed the memory deficits in the LPS-treated mice (p < 0.05). The increased oxidative stress and proinflammatory cytokines in the brain regions of the LPS-treated mice were significantly (p < 0.05) reduced by DRLC. DRLC (50 mg/kg and 100 mg/kg) also reduced acetyl-cholinesterase activity and decreased NF-κB expression in the brains of LPS-treated mice. Finally, it attenuated the cytoarchitectural distortions and loss of neuronal cells of the prefrontal cortex and hippocampus that were induced by LPS in mice. The results of this study suggest that DRLC attenuates memory deficit induced by LPS in mice through mechanisms related to the inhibition of oxidative stress, release of proinflammatory cytokines, and expression of NF-κB in mice.

Activation of α7 nAChR by PNU-282987 improves synaptic and cognitive functions through restoring the expression of synaptic-associated proteins and the CaM-CaMKII-CREB signaling pathway

Ligands of nicotinic acetylcholine receptors (nAChRs) are widely considered as potential therapeutic agents. The present study used primary hippocampus cells and APPswe/PSEN1dE9 double-transgenic mice models to study the possible therapeutic effect and underlying mechanism of the specific activation of α7 nAChR by PNU-282987 in the pathogenesis of Alzheimer’s disease. The results indicated that activation of α7 nAChR attenuated the Aβ-induced cell apoptosis, decreased the deposition of Aβ, increased the expression of synaptic-associated proteins, and maintained synaptic morphology. Furthermore, in the APP/PS1_DT mice model, activation of α7 nAChR attenuated Aβ-induced synaptic loss, reduced the deposition of Aβ in the hippocampus, maintained the integral structure of hippocampus-derived synapse, and activated the calmodulin (CaM)-calmodulin-dependent protein kinase II (CaMKII)-cAMP response element-binding protein signaling pathway by upregulation of its key signaling proteins. In addition, activation of α7 nAChR improved the learning and memory abilities of the APP/PS1_DT mice. Collectively, the activation of α7 nAChR by PNU-282987 attenuated the toxic effect of Aβ in vivo and in vitro, which including reduced deposition of Aβ in the hippocampus, maintained synaptic morphology by partially reversing the expression levels of synaptic-associated proteins, activation of the Ca²⁺ signaling pathway, and improvement of the cognitive abilities of APP/PS1_DT mice.

Neurological recovery and antioxidant effects of resveratrol in rats with spinal cord injury: a meta-analysis

Objective

To critically assess the neurological recovery and antioxidant effects of resveratrol in rat models of spinal cord injury.

Data sources

Using "spinal cord injury", "resveratrol" and "animal experiment" as the main search terms, all studies on the treatment of spinal cord injury in rats by resveratrol were searched for in PubMed, EMBASE, MEDLINE, Web of Science, Science Direct, China National Knowledge Infrastructure, Wanfang, VIP, and SinoMed databases by computer. The search was conducted from their inception date to April 2017. No language restriction was used in the literature search.

Data selection

The methodological quality of each study was assessed by the initial Stroke Therapy Academic Industry Roundtable recommendations. Two reviewers independently selected studies according to the title, abstract and full text. The risk of bias in the included studies was also evaluated. Meta-analyses were performed with Review Manager 5.3 software.

Outcome measures

Neurological function was assessed by the Basso, Beattie, and Bresnahan scale score, inclined plane score and Gale's motor function score. Molecular-biological analysis of antioxidative effects was conducted to determine superoxide dismutase levels, malondialdehyde levels, nitric oxide synthase activity, nitric oxide levels, xanthine oxidase and glutathione levels in spinal cord tissues.

Results

The methodological quality of the 12 included studies was poor. The results of meta-analysis showed that compared with the control group, resveratrol significantly increased the Basso, Beattie, and Bresnahan scale scores after spinal cord injury (n = 300, mean difference (MD) = 3.85, 95% confidence interval (CI) [2.10, 5.59], P < 0.0001). Compared with the control group, superoxide dismutase levels were significantly elevated (n = 138, standardized mean difference (SMD) = 5.22, 95% CI [2.98, 7.45], P < 0.00001), but malondialdehyde levels were significantly diminished (n = 84, SMD = -3.64, 95% CI [-5.84, -1.43], P = 0.001) in the spinal cord of the resveratrol treatment group.

Conclusions

Resveratrol promoted neurological recovery and exerted antioxidative effects in rat models of spinal cord injury. The limited quality of the included studies reduces the application of this meta-analysis. Therefore, more high-quality studies are needed to provide more rigorous and objective evidence for the pre-clinical treatment of spinal cord injury.

Current and emerging therapeutic targets of alzheimer's disease for the design of multi-target directed ligands

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, and a major cause of death worldwide. The number of people suffering from this debilitating disorder is rising at an unprecedented rate, with a subsequent surge in healthcare costs. Only four drugs are clinically available for the treatment of AD symptoms, but they are not disease-modifying. Consequently, there is an urgent need for a cure. Although the cause of this debilitating condition remains poorly understood, it is believed that several factors may be involved in combination - including, health and lifestyle, environmental, and genetic factors. In recent years, a number of hallmarks of the disease have also been discovered, and it is believed that these factors may play an important role in the development of AD. Amyloid aggregation is one such factor which has been highly investigated, in addition to cholinesterase enzymes and tau aggregation. In the last decade, multi-target drugs have been increasingly investigated for their application to AD treatment. By combining two or more pharmacophores in a single compound, it is possible to synthesise a drug which can target several factors that are involved in AD development. This is a particularly attractive approach as it would avoid the use of combination therapies. As a result, it could reduce the burden on carers and families, and decrease healthcare and social care costs. Many active pharmacophores have been employed for the development of hybrid drugs, due to their abilities to inhibit the factors currently widely recognised to be involved in AD. These compounds have demonstrated promising results; however, research is still required to optimise the pharmacological profiles of the drugs, in addition to their potencies. Meanwhile, extensive research is continuously being performed into other potential targets for the treatment of AD. Based on the results obtained thus far, it is likely that multi-target compounds will continue to be increasingly studied in the future as potential treatments for AD.

Pharmacokinetics and brain targeting of trans-resveratrol loaded mixed micelles in rats following intravenous administration

Trans-Resveratrol (T-RES) is a compound with wide therapeutic applications that shows low bioavailability and distribution across blood-brain barrier. The purpose of our study was to develop T-RES loaded mixed micelle (T-RES-MM) for its enhanced systemic availability and targeting to the brain. T-RES-MMs were formulated using Pluronic F-127 (PF-127) and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) by using film hydration process. Formulations were characterized for size of particles, zeta potential, drug efficiency of entrapment, drug loading, and hemolytic study. Further in vivo pharmacokinetic and brain distribution study carried out in Sprague Dawley rats. The nano ranged size for drug-loaded mixed micelles was 21.55 ± 2.15 nm for optimized formulation with PF-127:TPGS (4:1). Formulation with maximum drug loading and entrapment efficiency of 8.4 ± 0.37% and 94.37 ± 1.01% respectively were further used for in vivo study. Percent hemolysis by micelles at all concentrations indicates the biocompatibility and safety for administration by i.v. route. The AUC_0-t for T-RES-MM was 460.98 ± 158.99 h*ng/ml while for T-RES it was 276.27 ± 174.05 h*ng/ml. Drug targeting index suggests successful targeting of T-RES to the brain. Overall findings conclude in prepared T-RES-MM exhibit superiority of formulation as compared to T-RES solution.

B Vitamins and Fatty Acids: What Do They Share with Small Vessel Disease-Related Dementia?

Many studies have been written on vitamin supplementation, fatty acid, and dementia, but results are still under debate, and no definite conclusion has yet been drawn. Nevertheless, a significant amount of lab evidence confirms that vitamins of the B group are tightly related to gene control for endothelium protection, act as antioxidants, play a co-enzymatic role in the most critical biochemical reactions inside the brain, and cooperate with many other elements, such as choline, for the synthesis of polyunsaturated phosphatidylcholine, through S-adenosyl-methionine (SAM) methyl donation. B-vitamins have anti-inflammatory properties and act in protective roles against neurodegenerative mechanisms, for example, through modulation of the glutamate currents and a reduction of the calcium currents. In addition, they also have extraordinary antioxidant properties. However, laboratory data are far from clinical practice. Many studies have tried to apply these results in everyday clinical activity, but results have been discouraging and far from a possible resolution of the associated mysteries, like those represented by Alzheimer's disease (AD) or small vessel disease dementia. Above all, two significant problems emerge from the research: No consensus exists on general diagnostic criteria-MCI or AD? Which diagnostic criteria should be applied for small vessel disease-related dementia? In addition, no general schema exists for determining a possible correct time of implementation to have effective results. Here we present an up-to-date review of the literature on such topics, shedding some light on the possible interaction of vitamins and phosphatidylcholine, and their role in brain metabolism and catabolism. Further studies should take into account all of these questions, with well-designed and world-homogeneous trials.

Sirt1 enhances tau exon 10 inclusion and improves spatial memory of Htau mice

Alternative splicing of tau exon 10 generates tau isoforms with three or four microtubule binding repeats, named 3R-tau and 4R-tau, respectively. Dysregulation of tau exon 10 splicing could cause neurofibrillary degeneration. Acetylation is one of the major post-translational protein modifications in the cell by attachment of the acetyl group to either the α-amino group of the N-terminus of proteins or to the ε-amino group of lysine residues. Sirt1, one member in mammalian Sirtuin family, deacetylates protein and is associated closely with age-related diseases including Alzheimer’s disease. However, the role of Sirt1 in tau exon 10 splicing remains elusive. In the present study, we determined the role of Sirt1 in tau exon 10 splicing. We found that activation of Sirt1 by resveratrol enhanced tau exon 10 inclusion, leading to 4R-tau expression. Sirt1 interacted with splicing factor 9G8, deacetylated it at Lys24, and suppressed its function in promoting tau exon 10 exclusion. Moreover, resveratrol improved learning and spatial memory in Htau mice. These findings suggest that Sirt1 may serve as a new drug target for Alzheimer’s Disease related tauopathies and resveratrol may be used to correct dysregulated tau exon 10 with 3R-tau > 4R-tau.

Central nervous system SIRT1 expression is required for cued and contextual fear conditioning memory responses in aging mice

BACKGROUND:

Sirtuin 1 (SIRT1) is a NAD⁺-dependent enzyme that has important roles in many biological processes involved in aging, including cell growth and repair, inflammation, and energy regulation. SIRT1 activity is modulated in response to certain nutritional interventions that increase healthspan and longevity in rodents, including calorie restriction (CR) and intermittent fasting (IF). In addition to positively influencing cardiometabolic health, SIRT1 is important for brain health and may be critical in the preservation of memory processes that deteriorate during aging.

OBJECTIVE:

To investigate the role of brain-associated SIRT1 expression in the acquisition of fear memory in mice at 45 and 65 weeks of age.

METHODS:

Mice with brain-specific knock-out or overexpression of Sirt1 were assessed on a fear conditioning paradigm to determine the role of SIRT1 in fear memory acquisition.

RESULTS:

In the current study, mice lacking the expression of brain SIRT1 could not learn the fear conditioning paradigm during training, context, or cue phases.

CONCLUSIONS:

The results of the study indicate that SIRT1 expression in the brain is critical for the formation of fear memory in male mice at two distinct ages, highlighting the essential role of SIRT1 in fear memory acquisition during aging.

Mediterranean Diet in Preventing Neurodegenerative Diseases

PURPOSE OF REVIEW

We reviewed the most recent literature examining the associations between the Mediterranean-style diet (MD), neurodegenerative diseases, and markers and mechanisms of neurodegeneration.

RECENT FINDINGS

Most, but not all, epidemiologic studies report a protective association between MD adherence, cognitive impairment, and brain health. Data from clinical trials supporting these observational findings are also emerging. Limited evidence suggests that MD adherence may be protective for Parkinson's disease risk. Mechanistically, plant polyphenols may activate similar molecular pathways as caloric restriction diets, which helps explain the neuroprotective properties of the MD. Evidence for cognitive disorders is abundant, but there is a dearth of literature for other neurodegenerative disorders and for markers of neurodegeneration. Further research is needed to elucidate the protective role of MD on neurodegeneration, the most salient components of the MD, and the most sensitive time periods over the lifecourse at which the MD may exert its effects.