Resveratrol and Alzheimer's disease: message in a bottle on red wine and cognition

Impact of micronutrients and nutraceuticals on cognitive function and performance in Alzheimer's disease

Alzheimer's disease (AD) is a major global health problem today and is the most common form of dementia. AD is characterized by the formation of β-amyloid (Aβ) plaques and neurofibrillary clusters, leading to decreased brain acetylcholine levels in the brain. Another mechanism underlying the pathogenesis of AD is the abnormal phosphorylation of tau protein that accumulates at the level of neurofibrillary aggregates, and the areas most affected by this pathological process are usually the cholinergic neurons in cortical, subcortical, and hippocampal areas. These effects result in decreased cognitive function, brain atrophy, and neuronal death. Malnutrition and weight loss are the most frequent manifestations of AD, and these are also associated with greater cognitive decline. Several studies have confirmed that a balanced low-calorie diet and proper nutritional intake may be considered important factors in counteracting or slowing the progression of AD, whereas a high-fat or hypercholesterolemic diet predisposes to an increased risk of developing AD. Especially, fruits, vegetables, antioxidants, vitamins, polyunsaturated fatty acids, and micronutrients supplementation exert positive effects on aging-related changes in the brain due to their antioxidant, anti-inflammatory, and radical scavenging properties. The purpose of this review is to summarize some possible nutritional factors that may contribute to the progression or prevention of AD, understand the role that nutrition plays in the formation of Aβ plaques typical of this neurodegenerative disease, to identify some potential therapeutic strategies that may involve some natural compounds, in delaying the progression of the disease.

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

Why Is Iron Deficiency/Anemia Linked to Alzheimer's Disease and Its Comorbidities, and How Is It Prevented?

Impaired iron metabolism has been increasingly observed in many diseases, but a deeper, mechanistic understanding of the cellular impact of altered iron metabolism is still lacking. In addition, deficits in neuronal energy metabolism due to reduced glucose import were described for Alzheimer's disease (AD) and its comorbidities like obesity, depression, cardiovascular disease, and type 2 diabetes mellitus. The aim of this review is to present the molecular link between both observations. Insufficient cellular glucose uptake triggers increased ferritin expression, leading to depletion of the cellular free iron pool and stabilization of the hypoxia-induced factor (HIF) 1α. This transcription factor induces the expression of the glucose transporters (Glut) 1 and 3 and shifts the cellular metabolism towards glycolysis. If this first line of defense is not adequate for sufficient glucose supply, further reduction of the intracellular iron pool affects the enzymes of the mitochondrial electron transport chain and activates the AMP-activated kinase (AMPK). This enzyme triggers the translocation of Glut4 to the plasma membrane as well as the autophagic recycling of cell components in order to mobilize energy resources. Moreover, AMPK activates the autophagic process of ferritinophagy, which provides free iron urgently needed as a cofactor for the synthesis of heme- and iron-sulfur proteins. Excessive activation of this pathway ends in ferroptosis, a special iron-dependent form of cell death, while hampered AMPK activation steadily reduces the iron pools, leading to hypoferremia with iron sequestration in the spleen and liver. Long-lasting iron depletion affects erythropoiesis and results in anemia of chronic disease, a common condition in patients with AD and its comorbidities. Instead of iron supplementation, drugs, diet, or phytochemicals that improve energy supply and cellular glucose uptake should be administered to counteract hypoferremia and anemia of chronic disease.

The Effects of Momordica charantia on Type 2 Diabetes Mellitus and Alzheimer's Disease

T2DM is a complex metabolic disorder characterized by hyperglycemia and glucose intolerance. It is recognized as one of the most common metabolic disorders and its prevalence continues to raise major concerns in healthcare globally. Alzheimer's disease (AD) is a gradual neurodegenerative brain disorder characterized by the chronic loss of cognitive and behavioral function. Recent research suggests a link between the two diseases. Considering the shared characteristics of both diseases, common therapeutic and preventive agents are effective. Certain bioactive compounds such as polyphenols, vitamins, and minerals found in vegetables and fruits can have antioxidant and anti-inflammatory effects that allow for preventative or potential treatment options for T2DM and AD. Recently, it has been estimated that up to one-third of patients with diabetes use some form of complementary and alternative medicine. Increasing evidence from cell or animal models suggests that bioactive compounds may have a direct effect on reducing hyperglycemia, amplifying insulin secretion, and blocking the formation of amyloid plaques. One plant that has received substantial recognition for its numerous bioactive properties is Momordica charantia (M. charantia), otherwise known as bitter melon, bitter gourd, karela, and balsam pear. M. charantia is utilized for its glucose-lowering effects and is often used as a treatment for diabetes and related metabolic conditions amongst the indigenous populations of Asia, South America, India, and East Africa. Several pre-clinical studies have documented the beneficial effects of M. charantia through various postulated mechanisms. Throughout this review, the underlying molecular mechanisms of the bioactive components of M. charantia will be highlighted. More studies will be necessary to establish the clinical efficacy of the bioactive compounds within M. charantia to effectively determine its pertinence in the treatment of metabolic disorders and neurodegenerative diseases, such as T2DM and AD.

Comorbidity of osteoporosis and Alzheimer's disease: Is `AKT `-ing on cellular glucose uptake the missing link?

Osteoporosis and Alzheimer's disease (AD) are both degenerative diseases. Osteoporosis often proceeds cognitive deficits, and multiple studies have revealed common triggers that lead to energy deficits in brain and bone. Risk factors for osteoporosis and AD, such as obesity, type 2 diabetes, aging, chemotherapy, vitamin deficiency, alcohol abuse, and apolipoprotein Eε4 and/or Il-6 gene variants, reduce cellular glucose uptake, and protective factors, such as estrogen, insulin, exercise, mammalian target of rapamycin inhibitors, hydrogen sulfide, and most phytochemicals, increase uptake. Glucose uptake is a fine-tuned process that depends on an abundance of glucose transporters (Gluts) on the cell surface. Gluts are stored in vesicles under the plasma membrane, and protective factors cause these vesicles to fuse with the membrane, resulting in presentation of Gluts on the cell surface. This translocation depends mainly on AKT kinase signaling and can be affected by a range of factors. Reduced AKT kinase signaling results in intracellular glucose deprivation, which causes endoplasmic reticulum stress and iron depletion, leading to activation of HIF-1α, the transcription factor necessary for higher Glut expression. The link between diseases and aging is a topic of growing interest. Here, we show that diseases that affect the same biochemical pathways tend to co-occur, which may explain why osteoporosis and/or diabetes are often associated with AD.

Spousal bereavement and the cognitive health of older adults in the US: New insights on channels, single items, and subjective evidence

This study provides novel insights into older adults' cognitive functioning before and after widowhood onset and possible effect channels. It further examines gender heterogeneity in the adaptation to (anticipated or actual) spousal bereavement, comparing objective evidence with subjective evidence of cognitive abilities. We used longitudinal data of up to 26,584 participants of the Health and Retirement Study, aged over 50 at recruitment, assessed biennially between 1998 and 2016. Two-way fixed effects with dynamic treatment effects were estimated for various cognitive measures, including six aggregated indices and six single item scales. After adjusting for effect channels including depression, social vulnerability, and stress, there remained significant widowhood effects on older adults' cognitive health. Using single item scales, we established the adverse contemporaneous and adaptation effects on bereaved older females' short-term memory, semantic memory, and numeracy. For bereaved older males, working memory and focus-of-attention deteriorated after widowhood onset. Meanwhile, subjective memory rating remained intact, contrary to objective evidence. We conclude that cognitive transitions to and from widowhood can exhibit distinctive patterns across objective and subjective cognitive domains. With the effect channels in mind, cognitive intervention for widowed older adults should be tailored to the temporal distance to spousal loss, gender, and task.

Dietary Regulation of Gut-Brain Axis in Alzheimer's Disease: Importance of Microbiota Metabolites

Alzheimer's disease (AD) is a neurodegenerative disease that impacts 45 million people worldwide and is ranked as the 6th top cause of death among all adults by the Centers for Disease Control and Prevention. While genetics is an important risk factor for the development of AD, environment and lifestyle are also contributing risk factors. One such environmental factor is diet, which has emerged as a key influencer of AD development/progression as well as cognition. Diets containing large quantities of saturated/trans-fats, refined carbohydrates, limited intake of fiber, and alcohol are associated with cognitive dysfunction while conversely diets low in saturated/trans-fats (i.e., bad fats), high mono/polyunsaturated fats (i.e., good fats), high in fiber and polyphenols are associated with better cognitive function and memory in both humans and animal models. Mechanistically, this could be the direct consequence of dietary components (lipids, vitamins, polyphenols) on the brain, but other mechanisms are also likely to be important. Diet is considered to be the single greatest factor influencing the intestinal microbiome. Diet robustly influences the types and function of micro-organisms (called microbiota) that reside in the gastrointestinal tract. Availability of different types of nutrients (from the diet) will favor or disfavor the abundance and function of certain groups of microbiota. Microbiota are highly metabolically active and produce many metabolites and other factors that can affect the brain including cognition and the development and clinical progression of AD. This review summarizes data to support a model in which microbiota metabolites influence brain function and AD.

Novel strategies for the fight of Alzheimer's disease targeting amyloid-β protein

Alzheimer's disease (AD), which is recognised as a devastating neurodegenerative disease throughout the world and lack of effective treatments, is a growing concern in modern society with a growing population of elderly patients. A growing number of studies reveal that abnormal accumulation and deposition of Aβ is responsible for AD. Inspired by this, strategies for the treatment of AD targeting-Aβ clearance have been discussed for a long period, exploring new drugs which is capable of destroying soluble Aβ oligomers and unsolvable Aβ aggregates. In this paper, results of recent clinical trials on several anti-amyloid-β drugs are presented and several emerging anti-amyloid AD therapies based on recent studies are reviewed. Furthermore, some of the current challenges and novel strategies to prevent AD are addressed. Herein, this review focuses on current pharmacotherapy of AD targeting-Aβ and intends to design a promising therapeutic agent for AD treatment.

Study of Resveratrol's Interaction with Planar Lipid Models: Insights into Its Location in Lipid Bilayers

Resveratrol, a polyphenolic molecule found in edible fruits and vegetables, shows a wide range of beneficial effects on human health, including anti-microbial, anti-inflammatory, anti-cancer, and anti-aging properties. Due to its poor water solubility and high liposome-water partition coefficient, the biomembrane seems to be the main target of resveratrol, although the mode of interaction with membrane lipids and its location within the cell membrane are still unclear. In this study, using electrophysiological measurements, we study the interaction of resveratrol with planar lipid membranes (PLMs) of different composition. We found that resveratrol incorporates into palmitoyl-oleoyl-phosphatidylcholine (POPC) and POPC:Ch PLMs and forms conductive units unlike those found in dioleoyl-phosphatidylserine (DOPS):dioleoyl-phosphatidylethanolamine (DOPE) PLMs. The variation of the biophysical parameters of PLMs in the presence of resveratrol provides information on its location within a lipid double layer, thus contributing to an understanding of its mechanism of action.

Dietary phytochemicals that influence gut microbiota: Roles and actions as anti-Alzheimer agents

The last decide has witnessed a growing research interest in the role of dietary phytochemicals in influencing the gut microbiota. On the other hand, recent evidence reveals that dietary phytochemicals exhibit properties of preventing and tackling symptoms of Alzheimer's disease, which is a neurodegenerative disease that has also been linked with the status of the gut microbiota over the last decade. Till now, little serious discussions, however, have been made to link recent understanding of Alzheimer's disease, dietary phytochemicals and the gut microbiota together and to review the roles played by phytochemicals in gut dysbiosis induced pathologies of Alzheimer's disease. Deciphering these connections can provide insights into the development and future use of dietary phytochemicals as anti-Alzheimer drug candidates. This review aims at presenting latest evidence in the modulating role of phytochemicals in the gut microbiota and its relevance to Alzheimer's disease and summarizing the mechanisms behind the modulative activities. Limitations of current research in this field and potential directions will also be discussed for future research on dietary phytochemicals as anti-Alzheimer agents.

Beneficial Effects of Epigallocatechin-3-O-Gallate, Chlorogenic Acid, Resveratrol, and Curcumin on Neurodegenerative Diseases

Many observational and clinical studies have shown that consumption of diets rich in plant polyphenols have beneficial effects on various diseases such as cancer, obesity, diabetes, cardiovascular diseases, and neurodegenerative diseases (NDDs). Animal and cellular studies have indicated that these polyphenolic compounds contribute to such effects. The representative polyphenols are epigallocatechin-3-O-gallate in tea, chlorogenic acids in coffee, resveratrol in wine, and curcumin in curry. The results of human studies have suggested the beneficial effects of consumption of these foods on NDDs including Alzheimer's and Parkinson's diseases, and cellular animal experiments have provided molecular basis to indicate contribution of these representative polyphenols to these effects. This article provides updated information on the effects of these foods and their polyphenols on NDDs with discussions on mechanistic aspects of their actions mainly based on the findings derived from basic experiments.

Prospects Of Using Resveratrol For Cognitive Impairment Correction In Patients With Type II Diabetes Mellitus

Our goal was to study the effectiveness of resveratrol in correcting cognitive impairments and in normalization of neurotrophin levels in patients with type II diabetes mellitus. Material and Methods ― In a randomized placebo-controlled trial, 100 patients with a verified diagnosis of type II diabetes mellitus took part, who were subsequently placed into two groups: the treatment group of 50 patients taking a polyphenol therapeutic drug in addition to standard therapy, and the comparison group of 50 indivuduals taking a placebo medication in addition to standard therapy. The control group consisted of 30 individuals belonging to the health group I sensu RF Ministry of Healthcare. Treatment efficacy was assessed using the Montreal Cognitive Assessment (MoCA) scale. The concentrations of insulin-like growth factor 1 (IFR-1), brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) in blood plasma were analyzed before and after treatment completion (10 weeks later). Results ― Before starting treatment, patients exhibited an increase in the level of IFR-1 and a decrease in the content of neurotrophic factors (BDNF and NGF) in their blood plasma. In patients receiving resveratrol in addition to standard treatment, changes in IFR-1, BDNF and NGF in blood plasma were more noticeable relative to the comparison group and approached the values of the control group. According to the MoCA scale, more pronounced dynamics of cognitive functions was observed in patients of the treatment group. Conclusion ― The high efficiency of the polyphenol therapeutic drug resveratrol in the correction of cognitive impairments in patients with type II diabetes mellitus was established. The use of resveratrol promoted the normalization of the levels of IFR-1 and neurotrophic factors in the blood plasma: in the treatment group, a more pronounced statistically significant decrease in the concentration of IFR-1, along with an increase in BDNF and NGF levels, were observed relative to the control group. The clinically significant effect of resveratrol was in the reduction of cognitive deficit symptoms, which was confirmed by the data of dynamic monitoring on the MoCA scale: in treatment group, there was a statistically significant improvements of optical and spatial functions, attention, abstract thinking, and fulfilling delayed reproduction task; in the comparison group, there was a statistically significant improvement solely of completing delayed reproduction task.

Protections against toxicity in the brains of rat with chronic fluorosis and primary neurons exposed to fluoride by resveratrol involves nicotinic acetylcholine receptors

Protection of Resveratrol (RSV) against the neurotoxicity induced by high level of fluoride was investigated. Sprague-Dawley (SD) rats and their offspring, as well as cultures of primary neurons were divided randomly into four groups: untreated (control); treated with 50 mg RSV/kg/ (once daily by gavage) or (20 M in the cultured medium); exposed to 50 ppm F^- in drinking water or 4 mmol/l in the cultured medium; and exposed to fluoride then RSV as above. The adult rats were treated for 7 months and the offspring sacrificed at 28 days of age; the cultured neurons for 48 h. For general characterization, dental fluorosis was assessed and the fluoride content of the urine measured (by fluoride-electrode) in the rates and the survival of cultured neurons monitored with the CCK-8 test. The spatial learning and memory of rats were assessed with the Morris water maze test. The levels of α7 and α4 nicotinic acetylcholine receptors (nAChRs) were quantified by Western blotting; and the activities of superoxide dismutase (SOD) and catalase (CAT), and the levels of malondialdehyde (MDA) and H₂O₂ assayed biochemically. The results showed that chronic fluorosis resulted in the impaired learning and memory in rats and their offspring, and more oxidative stress in both rat brains and cultured neurons, which may be associated the lower levels of α7 and α4 nAChR subunits. Interestingly, RSV attenuated all of these toxic effects by fluorosis, indicating that protection against the neurotoxicity of fluoride by RSV might be in mechanism involved enhancing the expressions of these nAChRs.

Post-chemotherapy cognitive impairment in hematological patients: current understanding of chemobrain in hematology

Introduction: Cognitive impairment caused by chemotherapies, a condition known as chemobrain, is a possible side effect that affects alertness, learning, memory, and concentration.Areas covered: Chemobrain has been principally investigated as a possible side-effect among cancer patients. However, numerous drugs used to treat hematological malignancies can determine the appearance of chemobrain. In this review, we have examined some commonly used drugs for the treatment of hematological malignancies which are known to have a deleterious action on cognitive functions.Numerous mechanisms have been suggested, comprising the direct neurotoxicity of chemotherapeutic drugs, oxidative stress, genetic predisposition, cytokine-provoked damage, histone modifications, immune alteration, and the action of chemotherapeutic on trophic factors and structural proteins of brain cells.Expert commentary: Cognitive dysfunction provoked by the treatment of hematological diseases is an actual challenge in clinical practice. Actually, there are no totally efficient and innocuous treatments for this syndrome. It is important that further investigations specify the existence of predictors and gravity factors to pre- and post-therapy cognitive change and identify the influence of tumor treatments on the cognitive alterations in long-term, cancer survivors. Moreover, future studies are needed to analyze the interactions between genetic risk, amyloid accumulation, intrinsic brain networks, and chemotherapy.

Polyphenols from Food and Natural Products: Neuroprotection and Safety

Polyphenols are naturally occurring micronutrients that are present in many food sources. Besides being potent antioxidants, these molecules may also possess anti-inflammatory properties. Many studies have highlighted their potential role in the prevention and treatment of various pathological conditions connected to oxidative stress and inflammation (e.g., cancer, and cardiovascular and neurodegenerative disorders). Neurodegenerative diseases are globally one of the main causes of death and represent an enormous burden in terms of human suffering, social distress, and economic costs. Recent data expanded on the initial antioxidant-based mechanism of polyphenols’ action by showing that they are also able to modulate several cell-signaling pathways and mediators. The proposed benefits of polyphenols, either as protective/prophylactic substances or as therapeutic molecules, may be achieved by the consumption of a natural polyphenol-enriched diet, by their use as food supplements, or with formulations as pharmaceutical drugs/nutraceuticals. It has also been proved that the health effects of polyphenols depend on the consumed amount and their bioavailability. However, their overconsumption may raise safety concerns due to the accumulation of high levels of these molecules in the organism, particularly if we consider the loose regulatory legislation regarding the commercialization and use of food supplements. This review addresses the main beneficial effects of food polyphenols, and focuses on neuroprotection and the safety issues related to overconsumption.

Effect of nutrition on neurodegenerative diseases. A systematic review

Neurodegenerative diseases are characterized by the progressive functional loss of neurons in the brain, causing cognitive impairment and motoneuron disability. Although multifactorial interactions are evident, nutrition plays an essential role in the pathogenesis and evolution of these diseases. A systematic literature search was performed, and the prevalence of studies evaluated the effect of the Mediterranean diet (MeDiet), nutritional support, EPA and DHA, and vitamins on memory and cognition impairment. The data showed that malnutrition and low body mass index (BMI) is correlated with the higher development of dementia and mortality. MeDiet, nutritional support, and calorie-controlled diets play a protective effect against cognitive decline, Alzheimer's disease (AD), Parkinson disease (PD) while malnutrition and insulin resistance represent significant risk factors. Malnutrition activates also the gut-microbiota-brain axis dysfunction that exacerbate neurogenerative process. Omega-3 and -6, and the vitamins supplementation seem to be less effective in protecting neuron degeneration. Insulin activity is a prevalent factor contributing to brain health while malnutrition correlated with the higher development of dementia and mortality.

Nutrients in the Prevention of Alzheimer's Disease

Alzheimer's disease (AD) is a disease caused by the complex interaction of multiple mechanisms, some of which are still not fully understood. To date, pharmacological treatments and supplementation of individual nutrients have been poorly effective in terms of the prevention and treatment of AD, while alternative strategies based on multimodal approaches (diet, exercise, and cognitive training) seem to be more promising. In this context, the focus on dietary patterns rather than on single food components could be more useful in preventing or counteracting the pathological processes typical of AD, thanks to the potential synergistic effects of various nutrients (neuronutrients). The aim of this narrative review is to summarize the currently existing preclinical and clinical evidence regarding the Mediterranean diet (MeDi), the Dietary Approaches to Stop Hypertension (DASH) diet, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, which are three dietary patterns with well-known anti-inflammatory and antioxidant properties. Recently, they have been related to brain protection and AD prevention, perhaps thanks to their high content of neuroprotective bioactive compounds. Similarly, intermittent fasting (IF) or calorie restriction (CR) is emerging as interesting approaches that seem to promote hippocampal neurogenesis, activate adaptive stress response systems, and enhance neuronal plasticity, thus leading to motor and cognitive improvements in animal models of AD and hopefully also in human beings.

Effects of Second Language Learning on the Plastic Aging Brain: Functional Connectivity, Cognitive Decline, and Reorganization

Learning a new language requires the use of extensive neural networks and can represent a powerful tool to reorganize brain neuroplasticity. In this study, we analyze how a 4 months long second language learning program (16, 2 h sessions) can lead to functional changes in the brain of healthy elderly individuals. A large number of studies point out a decline of brain-skills with age; here it is analyzed how cognition together with functional brain organization can be improved later in life. Twenty-six older adults (59–79 years old) were enrolled in the present study. A complete neuropsychological examination was administered before and after the intervention to measure global cognition levels, short- and long-term memory, attention, language access and executive functions. At the end of the program, in the intervention group, the results showed a significant improvement in global cognition together with an increased functional connectivity in the right inferior frontal gyrus (rIFG), right superior frontal gyrus (rSFG) and left superior parietal lobule (lSPL). These findings can be added to the current neurobiological breakthroughs of reshaping brain networks with a short language learning practice in healthy elderly subjects. Therefore, learning a foreign-language may represent a potentially helpful cognitive intervention for promoting healthy aging.

The Amazon rain forest plant Uncaria tomentosa (cat's claw) and its specific proanthocyanidin constituents are potent inhibitors and reducers of both brain plaques and tangles

Brain aging and Alzheimer's disease both demonstrate the accumulation of beta-amyloid protein containing "plaques" and tau protein containing "tangles" that contribute to accelerated memory loss and cognitive decline. In the present investigation we identified a specific plant extract and its constituents as a potential alternative natural solution for preventing and reducing both brain "plaques and tangles". PTI-00703 cat's claw (Uncaria tomentosa from a specific Peruvian source), a specific and natural plant extract from the Amazon rain forest, was identified as a potent inhibitor and reducer of both beta-amyloid fibrils (the main component of "plaques") and tau protein paired helical filaments/fibrils (the main component of "tangles"). PTI-00703 cat's claw demonstrated both the ability to prevent formation/aggregation and disaggregate preformed Aβ fibrils (1-42 and 1-40) and tau protein tangles/filaments. The disaggregation/dissolution of Aβ fibrils occurred nearly instantly when PTI-00703 cat's claw and Aβ fibrils were mixed together as shown by a variety of methods including Thioflavin T fluorometry, Congo red staining, Thioflavin S fluorescence and electron microscopy. Sophisticated structural elucidation studies identified the major fractions and specific constituents within PTI-00703 cat's claw responsible for both the observed "plaque" and "tangle" inhibitory and reducing activity. Specific proanthocyanidins (i.e. epicatechin dimers and variants thereof) are newly identified polyphenolic components within Uncaria tomentosa that possess both "plaque and tangle" reducing and inhibitory activity. One major identified specific polyphenol within PTI-00703 cat's claw was epicatechin-4β-8-epicatechin (i.e. an epicatechin dimer known as proanthocyanidin B2) that markedly reduced brain plaque load and improved short-term memory in younger and older APP "plaque-producing" (TASD-41) transgenic mice (bearing London and Swedish mutations). Proanthocyanidin B2 was also a potent inhibitor of brain inflammation as shown by reduction in astrocytosis and gliosis in TASD-41 transgenic mice. Blood-brain-barrier studies in Sprague-Dawley rats and CD-1 mice indicated that the major components of PTI-00703 cat's claw crossed the blood-brain-barrier and entered the brain parenchyma within 2 minutes of being in the blood. The discovery of a natural plant extract from the Amazon rain forest plant (i.e. Uncaria tomentosa or cat's claw) as both a potent "plaque and tangle" inhibitor and disaggregator is postulated to represent a potential breakthrough for the natural treatment of both normal brain aging and Alzheimer's disease.

Effects and Underlying Mechanisms of Bioactive Compounds on Type 2 Diabetes Mellitus and Alzheimer's Disease

Type 2 diabetes mellitus is a complicated metabolic disorder characterized by hyperglycemia and glucose intolerance. Alzheimer's disease is a progressive brain disorder characterized by a chronic loss of cognitive and behavioral function. Considering the shared characteristics of both diseases, common therapeutic and preventive agents may be effective. Bioactive compounds such as polyphenols, vitamins, and carotenoids found in vegetables and fruits can have antioxidant and anti-inflammatory effects. These effects make them suitable candidates for the prevention or treatment of diabetes and Alzheimer's disease. Increasing evidence from cell or animal models suggest that bioactive compounds may have direct effects on decreasing hyperglycemia, enhancing insulin secretion, and preventing formation of amyloid plaques. The possible underlying molecular mechanisms are described in this review. More studies are needed to establish the clinical effects of bioactive compounds.

A comparison of resveratrol and other polyphenolic compounds on Notch activation and endothelial cell activity

Resveratrol is a polyphenolic compound produced by plants which makes its way into the human diet through plant-based foods. It has been shown to provide many health benefits, helping to ward of age-related diseases and promoting cardiovascular health. Additionally, resveratrol is a potent activator of the Notch signaling pathway. While resveratrol receives the most attention as a polyphenolic nutraceutical, other compounds with similar structures may be more potent regulators of specific cellular processes. Here, we compare resveratrol, apigenin, chrysin, genistein, luteolin, myricetin, piceatannol, pterostilbene, and quercetin for their ability to regulate Notch signaling. In addition, we compare the ability of these polyphenolic compounds to regulate endothelial cell viability, proliferation, and migration. Out of these compounds we found that resveratrol is the best activator of Notch signaling, however, other similar compounds are also capable of stimulating Notch. We also discovered that several of these polyphenols were able to inhibit endothelial cell proliferation. Finally, we found that many of these polyphenols are potent inhibitors of endothelial migration during wound healing assays. These findings provide the first side-by-side comparison of the regulation of Notch signaling, and endothelial cell proliferation and migration, by nine polyphenolic compounds.

Resveratrol Brain Delivery for Neurological Disorders Prevention and Treatment

Resveratrol (RES) is a natural polyphenolic non-flavonoid compound present in grapes, mulberries, peanuts, rhubarb and in several other plants. Numerous health effects have been related with its intake, such as anti-carcinogenic, anti-inflammatory and brain protective effects. The neuroprotective effects of RES in neurological diseases, such as Alzheimer's (AD) and Parkinson's (PD) diseases, are related to the protection of neurons against oxidative damage and toxicity, and to the prevention of apoptotic neuronal death. In brain cancer, RES induces cell apoptotic death and inhibits angiogenesis and tumor invasion. Despite its great potential as therapeutic agent for the treatment of several diseases, RES exhibits some limitations. It has poor water solubility and it is chemically instable, being degraded by isomerization once exposed to high temperatures, pH changes, UV light, or certain types of enzymes. Thus, RES has low bioavailability, limiting its biological and pharmacological benefits. To overcome these limitations, RES can be delivered by nanocarriers. This field of nanomedicine studies how the drug administration, pharmacokinetics, and pharmacodynamics are affected by the use of nanosized materials. The role of nanotechnology, in the prevention and treatment of neurological diseases, arises from the necessity to mask the physicochemical properties of therapeutic drugs to prolong the half-life and to be able to cross the blood-brain barrier (BBB). This can be achieved by encapsulating the drug in a nanoparticle (NP), which can be made of different kinds of materials. An increasing trend to encapsulate and direct RES to the brain has been observed. RES has been encapsulated in many different types of nanosystems, as liposomes, lipid and polymeric NPs. Furthermore, some of these nanocarriers have been modified with targeting molecules able to recognize the brain areas. Then, this article aims to overview the RES benefits and limitations in the treatment of neurological diseases, as the different nanotechnology strategies to overcome these limitations.

Grape skin extract improves muscle function and extends lifespan of a Drosophila model of Parkinson's disease through activation of mitophagy

Recent studies suggest that moderate red wine consumption may confer several health benefits, including protection against heart disease, certain cancers and multiple age-related neurological diseases such as Alzheimer's disease. These health benefits are assumed to come from a compound from grape skin called resveratrol, which has been proposed to be a pro-longevity agent. Whether resveratrol accounts for all the health benefits of grape-derived nutrients and the molecular and cellular mechanisms underlying the beneficial effects of such nutrients are not well understood. Here we investigated the effect of supplementing grape skin extract (GSE) left from red wine-production process to the daily food intake of a Drosophila melanogaster model of Parkinson's disease (PD) associated with PTEN-induced kinase 1 (PINK1) loss-of-function. Consumption of GSE resulted in rescue of mitochondrial morphological defects, improvement of indirect flight muscle function and health-span, and prolonged lifespan of the PINK1 mutant flies. Further biochemical and genetic studies revealed a link between activation of mitophagy and the beneficial effects of GSE. Our results indicate that GSE can promote autophagy activation, preserve mitochondria function, and protect against PD pathogenesis, and that the beneficial effect of GSE in mitophagy activation is not accounted for by resveratrol alone.

Connection between Systemic Inflammation and Neuroinflammation Underlies Neuroprotective Mechanism of Several Phytochemicals in Neurodegenerative Diseases

Oxidative damage, mitochondrial dysfunction, and neuroinflammation are strongly implicated in the pathogenesis of neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD), and a substantial portion of elderly population at risk of these diseases requires nutritional intervention to benefit health due to lack of clinically relevant drugs. To this end, anti-inflammatory mechanisms of several phytochemicals such as curcumin, resveratrol, propolis, polyunsaturated fatty acids (PUFAs), and ginsenosides have been extensively studied. However, correlation of the phytochemicals with neuroinflammation or brain nutrition is not fully considered, especially in their therapeutic mechanism for neuronal damage or dysfunction. In this article, we review the advance in antioxidative and anti-inflammatory effects of phytochemicals and discuss the potential communication with brain microenvironment by improved gastrointestinal function, enhanced systemic immunity, and neuroprotective outcomes. These data show that phytochemicals may modulate and suppress neuroinflammation of the brain by several approaches: (1) reducing systemic inflammation and infiltration via the blood-brain barrier (BBB), (2) direct permeation into the brain parenchyma leading to neuroprotection, (3) enhancing integrity of disrupted BBB, and (4) vagal reflex-mediated nutrition and protection by gastrointestinal function signaling to the brain. Therefore, many phytochemicals have multiple potential neuroprotective approaches contributing to therapeutic benefit for pathogenesis of neurodegenerative diseases, and development of strategies for preventing these diseases represents a considerable public health concern and socioeconomic burden.

Wine: An Aspiring Agent in Promoting Longevity and Preventing Chronic Diseases

INTRODUCTION

Moderate wine consumption is a characteristic of the Mediterranean diet. Studies around the world have shown a beneficial effect of moderate alcohol intake, especially wine, on health. This review aims to critically summarise the most recent studies that investigate the beneficial effects of moderate wine intake on human health.

METHODS

The PubMed database was comprehensively searched to identify trials published from 2013 to 2018 that investigated the association between moderate wine consumption and health.

RESULTS

The most recent studies confirm the valuable role of moderate wine consumption, especially red wine, in the prevention and treatment of chronic diseases such as cardiovascular disease, metabolic syndrome, cognitive decline, depression, and cancer. In the meantime, recent studies also highlight the beneficial role of red wine against oxidative stress and in favour of desirable gut bacteria. The beneficial role of red wine has been attributed to its phytochemical compounds, as highlighted by clinical trials, where the effect of red wine has been compared to white wine, non-alcoholic wine, other alcoholic drinks, and water.

CONCLUSIONS

Moderate wine intake, at 1⁻2 glasses per day as part of the Mediterranean diet, has been positively associated with human health promotion, disease prevention, and disease prognosis.

Overexpression of Kinesin Superfamily Motor Proteins in Alzheimer's Disease

Defects in motor protein-mediated neuronal transport mechanisms have been implicated in a number of neurodegenerative disorders but remain relatively little studied in Alzheimer's disease (AD). Our aim in the present study was to assess the expression of the anterograde kinesin superfamily motor proteins KIF5A, KIF1B, and KIF21B, and to examine their relationship to levels of hyperphosphorylated tau, amyloid-β protein precursor (AβPP), and amyloid-β (Aβ) in human brain tissue. We used a combination of qPCR, immunoblotting, and ELISA to perform these analyses in midfrontal cortex from 49 AD and 46 control brains. Expression of KIF5A, KIF1B, and KIF21B at gene and protein level was significantly increased in AD. KIF5A protein expression correlated inversely with the levels of AβPP and soluble Aβ in AD brains. Upregulation of KIFs may be an adaptive response to impaired axonal transport in AD.

Prospective Associations between Single Foods, Alzheimer's Dementia and Memory Decline in the Elderly

Background: Evidence whether single &ldquo;cognitive health&rdquo; foods could prevent cognitive decline is limited. We investigated whether dietary intake of red wine, white wine, coffee, green tea, olive oil, fresh fish, fruits and vegetables, red meat and sausages, assessed by a single-food-questionnaire, would be associated with either incident Alzheimer&rsquo;s dementia (AD) or verbal memory decline. Methods: Participants aged 75+ of the German Study on Aging, Cognition and Dementia in Primary Care Patients (AgeCoDe) cohort were regularly followed over 10 years (n = 2622; n = 418 incident AD cases). Multivariable-adjusted joint modeling of repeated-measures and survival analysis was used, taking gender and Apolipoprotein E4 (APOE &epsilon;4) genotype into account as possible effect modifiers. Results: Only higher red wine intake was associated with a lower incidence of AD (HR = 0.92; P = 0.045). Interestingly, this was true only for men (HR = 0.82; P < 0.001), while in women higher red wine intake was associated with a higher incidence of AD (HR = 1.15; P = 0.044), and higher white wine intake with a more pronounced memory decline over time (HR = &minus;0.13; P = 0.052). Conclusion: We found no evidence for these single foods to be protective against cognitive decline, with the exception of red wine, which reduced the risk for AD only in men. Women could be more susceptible to detrimental effects of alcohol.

Neuro-nutrients as anti-alzheimer's disease agents: A critical review

Alzheimer's disease (AD) is characterized by a massive neuronal death causing memory loss, cognitive impairment and behavioral alteration that ultimately lead to dementia and death. AD is a multi-factorial pathology controlled by molecular events such as oxidative stress, protein aggregation, mitochondrial dysfunction and neuro inflammation. Nowadays, there is no efficient disease-modifying treatment for AD and epidemiological studies have suggested that diet and nutrition have a significant impact on the development of this disorder. Indeed, some nutrients can protect all kind of cells, including neurons. As prevention is better than cure, life style improvement, with a special emphasis on diet, should seriously be considered as an anti-AD track and intake of nutrients promoting neuronal health is the need of the hour. Diets rich in unsaturated fatty acids, polyphenols and vitamins have been shown to protect against AD, whereas saturated fatty acids-containing diets deprived of polyphenols promote the development of the disease. Thus, Mediterranean diets, mainly composed of fruits, vegetables and omega-3 fatty acids, stand as valuable, mild and preventive anti-AD agents. This review focuses on our current knowledge in the field and how one can fight this devastating neurodegenerative disorder through the simple proper modification of our life style.

Resveratrol Prevents the Cellular Damages Induced by Monocrotophos via PI3K Signaling Pathway in Human Cord Blood Mesenchymal Stem Cells

The role of resveratrol (RV) as a neuroprotectant is well recognized, and cellular molecules involved in imparting the physiological effect have been well illustrated. However, some ambiguity still prevails as the specific receptor, and downstream signaling molecules are not yet clearly stated. So, we investigated the signaling pathway(s) involved in its cellular protection in the human umbilical cord blood mesenchymal stem cell (hUCB-MSC) derived neuronal cells. The mesenchymal stem cells were exposed to various concentrations (10, 100, 1000 μM) of monocrotophos (MCP), a known developmental neurotoxic organophosphate pesticide, for a period of 24 h. The MAPK signaling pathways (JNK, p38, and ERK) known to be associated with MCP-induced damages were also taken into consideration to identify the potential connection. The biological safe dose of RV (10 μM) shows a significant restoration in the MCP-induced alterations. Under the specific growth conditions, RV exposure was found to promote neuronal differentiation in the hUCB-MSCs. The exposure of cells to a specific pharmacological inhibitor (LY294002) of PI3K confirms the significant involvement of PI3K-mediated pathway in the ameliorative responses of RV against MCP exposure. Our data identifies the substantial role of RV in the restoration of MCP-induced cellular damages, thus proving to have a therapeutic potential against organophosphate pesticide-induced neurodegeneration.

Inhibition of oxidative stress in cholinergic projection neurons fully rescues aging-associated olfactory circuit degeneration in Drosophila

Loss of the sense of smell is among the first signs of natural aging and neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Cellular and molecular mechanisms promoting this smell loss are not understood. Here, we show that Drosophila melanogaster also loses olfaction before vision with age. Within the olfactory circuit, cholinergic projection neurons show a reduced odor response accompanied by a defect in axonal integrity and reduction in synaptic marker proteins. Using behavioral functional screening, we pinpoint that expression of the mitochondrial reactive oxygen scavenger SOD2 in cholinergic projection neurons is necessary and sufficient to prevent smell degeneration in aging flies. Together, our data suggest that oxidative stress induced axonal degeneration in a single class of neurons drives the functional decline of an entire neural network and the behavior it controls. Given the important role of the cholinergic system in neurodegeneration, the fly olfactory system could be a useful model for the identification of drug targets.

Health benefits of walnut polyphenols: An exploration beyond their lipid profile

Walnuts are commonly found in our diet and have been recognized for their nutritious properties for a long time. Traditionally, walnuts have been known for their lipid profile, which has been linked to a wide array of biological properties and health-promoting effects. In addition to essential fatty acids, walnuts contain a variety of other bioactive compounds, such as vitamin E and polyphenols. Among common foods and beverages, walnuts represent one of the most important sources of polyphenols, hence their effect over human health warrants attention. The main polyphenol in walnuts is pedunculagin, an ellagitannin. After consumption, ellagitannins are hydrolyzed to release ellagic acid, which is converted by gut microflora to urolithin A and other derivatives such as urolithins B, C, and D. Ellagitannins possess well known antioxidant and anti-inflammatory bioactivity, and several studies have assessed the potential role of ellagitannins against disease initiation and progression, including cancer, cardiovascular, and neurodegenerative diseases. The purpose of this review is to summarize current available information relating to the potential effect of walnut polyphenols in health maintenance and disease prevention.

Ferulic acid and its water-soluble derivatives inhibit nitric oxide production and inducible nitric oxide synthase expression in rat primary astrocytes

We recently reported that two water-soluble derivatives of ferulic acid (1-feruloyl glycerol, 1-feruloyl diglycerol) previously developed by our group exhibited protective effects against amyloid-β–induced neurodegeneration in vitro and in vivo. In the current study, we aimed to further understand this process by examining the derivatives’ ability to suppress abnormal activation of astrocytes, the key event of neurodegeneration. We investigated the effects of ferulic acid (FA) derivatives on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in rat primary astrocytes. The results showed that these compounds inhibited NO production and iNOS expression in a concentration-dependent manner and that the mechanism underlying these effects was the suppression of the nuclear factor-κB pathway. This evidence suggests that FA and its derivatives may be effective neuroprotective agents and could be useful in the treatment of neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease.

Resveratrol Attenuates Aβ-Induced Early Hippocampal Neuron Excitability Impairment via Recovery of Function of Potassium Channels

Alzheimer's disease (AD) is an age-related neurodegenerative disease. Amyloid-β (Aβ) is not only the morphological hallmark but also the initiator of the pathology process of AD. As a natural compound found in grapes, resveratrol shows a protective effect on the pathophysiology of AD, but the underlying mechanism is not very clear. This study was to investigate whether resveratrol could attenuate Aβ-induced early impairment in hippocampal neuron excitability and the underlying mechanism. The excitability and voltage-gated potassium currents were examined in rat hippocampal CA1 pyramidal neurons by using whole-cell patch-clamp technique. It was found that Aβ_25-35 increased the excitability of neurons. Resveratrol could reverse the Aβ_25-35-induced increase in the frequency of repetitive firing and the spike half-width of action potential (AP). Moreover, resveratrol can attenuate Aβ_25-35-induced decreases in transient potassium channel (I _A ) and delay rectifier potassium channel (I _K(DR)) of neurons. It was also found that resveratrol could decline the increase of protein kinase A (PKA) and inhibit the activation of PI3K/Akt signaling pathway induced by Aβ_25-35. The results suggest that resveratrol alleviates Aβ_25-35-induced dysfunction in hippocampal CA1 pyramidal neurons via recovery of the function of I _A and I _K(DR) by inhibiting the increase of PKA and the activation of PI3K/Akt signaling pathway.

The paradoxical pro- and antiangiogenic actions of resveratrol: therapeutic applications in cancer and diabetes

Resveratrol, a polyphenol found in grapes, peanuts, and red wine, plays different roles in diseases such as cancer and diabetes. Existing information indicates that resveratrol provides cardioprotection, as evidenced by superior postischemic ventricular recovery, reduced myocardial infarct size, and decreased number of apoptotic cardiomyocytes associated with resveratrol treatment in animal models. Cardiovascular benefits are experienced in humans with routine but not acute consumption of red wine. In this concise review, the paradoxical pro- and antiangiogenic effects of resveratrol are described, and different roles for resveratrol in the formation of new blood vessels are explained through different mechanisms. It is hypothesized that the effects of resveratrol on different cell types are not only dependent on its concentration but also on the physical and chemical conditions surrounding cells. The findings discussed herein shed light on potential therapeutic proapoptotic and antiangiogenic applications of low-dose resveratrol treatment in the prevention and treatment of different diseases.

Nutritional strategies to optimise cognitive function in the aging brain

Old age is the greatest risk factor for most neurodegenerative diseases. During recent decades there have been major advances in understanding the biology of aging, and the development of nutritional interventions that delay aging including calorie restriction (CR) and intermittent fasting (IF), and chemicals that influence pathways linking nutrition and aging processes. CR influences brain aging in many animal models and recent findings suggest that dietary interventions can influence brain health and dementia in older humans. The role of individual macronutrients in brain aging also has been studied, with conflicting results about the effects of dietary protein and carbohydrates. A new approach known as the Geometric Framework (GF) has been used to unravel the complex interactions between macronutrients (protein, fat, and carbohydrate) and total energy on outcomes such as aging. These studies have shown that low-protein, high-carbohydrate (LPHC) diets are optimal for lifespan in ad libitum fed animals, while total calories have minimal effect once macronutrients are taken into account. One of the primary purposes of this review is to explore the notion that macronutrients may have a more translational potential than CR and IF in humans, and therefore there is a pressing need to use GF to study the impact of diet on brain aging. Furthermore, given the growing recognition of the role of aging biology in dementia, such studies might provide a new approach for dietary interventions for optimizing brain health and preventing dementia in older people.

Association between alcohol and Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by dense deposition of amyloid-β (Aβ) protein in the brain, failure of the memory and dementia. At present, there is no cure for AD and current treatments only provide a temporary reduction of symptoms. Thus, there is a need for effective preventive/curative strategic approaches. Accordingly, epidemiological studies have reported a reduction in the prevalence of AD in individuals ingesting low amounts of alcohol, while a moderate consumption of ethanol may protect against Aβ. These data are conflicting with other observations that assigned detrimental effects of heavy alcohol use on brain function, which are apparently similar to those observed in AD. These discrepancies questioned whether or not alcohol is a protective agent against the development of AD, whether the probable protective effects are influenced by the quantity and/or frequency of drinking. These issues are addressed in this review with the aim to suggest the real risk of alcohol for developing or preventing AD.

Mechanism of uncoupling protein 2‑mediated myocardial injury in hypothermic preserved rat hearts

In the present study, the alterations in uncoupling protein 2 (UCP2) expression following hypothermic preservation in rat hearts were investigated. Isolated rat hearts were preserved in Celsior solution for 3‑12 h followed by 60 min of reperfusion. The cardiac function was evaluated using the Langendorff perfusion system. UCP2 and silent mating type information regulation 2 homolog 1 (SIRT1) proteins were detected by western blot analysis. The ATP production and mitochondrial reactive oxygen species (ROS) levels were assessed. Subsequent to preservation in ice‑cold Celsior solution for 3‑12 h, the UCP2 protein expression in rat hearts was observed to increase in a time‑dependent manner. The UCP2 inhibitor genipin inhibited the hypothermic preservation‑induced cardiac dysfunction, prevented a decline in ATP production induced by 9 h of preservation, however had no effect on the hypothermic preservation‑induced increase in mitochondrial ROS levels. Compared with the control group, the SIRT1 protein expression in rat hearts reduced following hypothermic preservation. Compared with the 9‑h preservation group, Celsior solution supplemented with the SIRT1 activator resveratrol (20 or 40 µmol/l) inhibited UCP2 protein overexpression, prevented the decline in ATP production and resulted in an improvement cardiac function. The SIRT1 inhibitor EX‑527 abolished the resveratrol‑induced inhibition of UCP2 overexpression and cardiac protection in the hypothermic preserved rat heart. These observations suggest that downregulation of UCP2 expression in the hypothermic preserved rat heart in part initiated the protective mechanism via the SIRT1 pathway.

Protective Effects of Forskolin on Behavioral Deficits and Neuropathological Changes in a Mouse Model of Cerebral Amyloidosis

The production of amyloid-β peptides in the brains of patients with Alzheimer disease (AD) may contribute to memory loss and impairments in social behavior. Here, an efficient adenylate cyclase activator, forskolin, was orally administered by gavage (100 mg/kg body weight) to 5-month-old transgenic APP/PS1 mice, which serve as an animal model of cerebral amyloidosis. Analyses of nest construction, sociability, and immunohistochemical features were used to determine the effects of forskolin treatment. After a relatively short term of treatment (10 days), forskolin-treated transgenic mice showed restored nest construction ability (p < 0.05) and their sociability (p < 0.01). There was a reduction of Aβ plaque deposition in the cortex and in the hippocampus. Furthermore, expression of transforming growth factor β, glial fibrillary acidic protein, and Iba-1 in the cortex was reduced in the forskolin-treated group, suggesting regulation of the inflammatory response mediated by activated microglia and astrocytes in the brains of the APP/PS1 mice (p < 0.01). Taken together, these findings suggest that forskolin shows neuroprotective effects in APP/PS1 Tg mice and may be a promising drug in the treatment of patients with AD.

Structure-Activity Relationship Studies of Isomeric 2,4-Diaminoquinazolines on β-Amyloid Aggregation Kinetics

A library of isomeric 2,4-diaminoquinazoline (DAQ) derivatives were synthesized and evaluated for antiaggregation potential toward Aβ40/42. Structure-activity relationship data identified compound 3k (N (4)-(4-bromobenzyl)quinazoline-2,4-diamine) with a 4-bromobenzyl substituent as the most potent inhibitor (Aβ40 IC50 = 80 nM) and was almost 18-fold more potent compared to the reference agent curcumin (Aβ40 IC50 = 1.5 μM). The corresponding N (2)-isomer 4k (N (2)-(4-bromobenzyl)quinazoline-2,4-diamine) was also able to prevent Aβ aggregation (Aβ40 IC50 = 1.7 μM). However, compound 4k exhibited superior inhibition of Aβ42 aggregation (Aβ42 IC50 = 1.7 μM) compared to compound 3k (Aβ42 IC50 = 14.8 μM) and was ∼1.8-fold more potent compared to curcumin (Aβ42 IC50 = 3.1 μM). These results were supported by Aβ aggregation kinetics investigations and transmission electron microscopy studies, which demonstrate the suitability of DAQ ring system to develop antiamyloid agents as pharmacological tools to study Aβ aggregation.

Resveratrol Antagonizes Antimicrobial Lethality and Stimulates Recovery of Bacterial Mutants

Reactive oxygen species (ROS; superoxide, peroxide, and hydroxyl radical) are thought to contribute to the rapid bactericidal activity of diverse antimicrobial agents. The possibility has been raised that consumption of antioxidants in food may interfere with the lethal action of antimicrobials. Whether nutritional supplements containing antioxidant activity are also likely to interfere with antimicrobial lethality is unknown. To examine this possibility, resveratrol, a popular antioxidant dietary supplement, was added to cultures of Escherichia coli and Staphylococcus aureus that were then treated with antimicrobial and assayed for bacterial survival and the recovery of mutants resistant to an unrelated antimicrobial, rifampicin. Resveratrol, at concentrations likely to be present during human consumption, caused a 2- to 3-fold reduction in killing during a 2-hr treatment with moxifloxacin or kanamycin. At higher, but still subinhibitory concentrations, resveratrol reduced antimicrobial lethality by more than 3 orders of magnitude. Resveratrol also reduced the increase in reactive oxygen species (ROS) characteristic of treatment with quinolone (oxolinic acid). These data support the general idea that the lethal activity of some antimicrobials involves ROS. Surprisingly, subinhibitory concentrations of resveratrol promoted (2- to 6-fold) the recovery of rifampicin-resistant mutants arising from the action of ciprofloxacin, kanamycin, or daptomycin. This result is consistent with resveratrol reducing ROS to sublethal levels that are still mutagenic, while the absence of resveratrol allows ROS levels to high enough to kill mutagenized cells. Suppression of antimicrobial lethality and promotion of mutant recovery by resveratrol suggests that the antioxidant may contribute to the emergence of resistance to several antimicrobials, especially if new derivatives and/or formulations of resveratrol markedly increase bioavailability.

Effects of Ethanol on the Expression Level of Various BDNF mRNA Isoforms and Their Encoded Protein in the Hippocampus of Adult and Embryonic Rats

We aimed to compare the effects of oral ethanol (Eth) alone or combined with the phytoestrogen resveratrol (Rsv) on the expression of various brain-derived neurotrophic factor (BDNF) transcripts and the encoded protein pro-BDNF in the hippocampus of pregnant and embryonic rats. A low (0.25 g/kg body weight (BW)/day) dose of Eth produced an increase in the expression of BDNF exons I, III and IV and a decrease in that of the exon IX in embryos, but failed to affect BDNF transcript and pro-BDNF protein expression in adults. However, co-administration of Eth 0.25 g/kg·BW/day and Rsv led to increased expression of BDNF exons I, III and IV and to a small but significant increase in the level of pro-BDNF protein in maternal rats. A high (2.5 g/kg·BW/day) dose of Eth increased the expression of BDNF exons III and IV in embryos, but it decreased the expression of exon IX containing BDNF mRNAs in the maternal rats. While the high dose of Eth alone reduced the level of pro-BDNF in adults, it failed to change the levels of pro-BDNF in embryos. Eth differentially affects the expression pattern of BDNF transcripts and levels of pro-BDNF in the hippocampus of both adult and embryonic rats.

The Role of Oxidative Stress-Induced Epigenetic Alterations in Amyloid-β Production in Alzheimer's Disease

An increasing number of studies have proposed a strong correlation between reactive oxygen species (ROS)-induced oxidative stress (OS) and the pathogenesis of Alzheimer's disease (AD). With over five million people diagnosed in the United States alone, AD is the most common type of dementia worldwide. AD includes progressive neurodegeneration, followed by memory loss and reduced cognitive ability. Characterized by the formation of amyloid-beta (Aβ) plaques as a hallmark, the connection between ROS and AD is compelling. Analyzing the ROS response of essential proteins in the amyloidogenic pathway, such as amyloid-beta precursor protein (APP) and beta-secretase (BACE1), along with influential signaling programs of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and c-Jun N-terminal kinase (JNK), has helped visualize the path between OS and Aβ overproduction. In this review, attention will be paid to significant advances in the area of OS, epigenetics, and their influence on Aβ plaque assembly. Additionally, we aim to discuss available treatment options for AD that include antioxidant supplements, Asian traditional medicines, metal-protein-attenuating compounds, and histone modifying inhibitors.

Western diet is associated with a smaller hippocampus: a longitudinal investigation

BACKGROUND

Recent meta-analyses confirm a relationship between diet quality and both depression and cognitive health in adults. While the biological pathways that underpin these relationships are likely multitudinous, extensive evidence from animal studies points to the involvement of the hippocampus. The aim of this study was to examine the association between dietary patterns and hippocampal volume in humans, and to assess whether diet was associated with differential rates of hippocampal atrophy over time.

METHODS

Data were drawn from the Personality and Total Health Through Life Study and focused on a subsample of the cohort (n = 255) who were aged 60-64 years at baseline in 2001, completed a food frequency questionnaire, and underwent two magnetic resonance imaging scans approximately 4 years apart. Longitudinal generalized estimating equation linear regression models were used to assess the association between dietary factors and left and right hippocampal volumes over time.

RESULTS

Every one standard deviation increase in healthy "prudent" dietary pattern was associated with a 45.7 mm(3) (standard error 22.9 mm(3)) larger left hippocampal volume, while higher consumption of an unhealthy "Western" dietary pattern was (independently) associated with a 52.6 mm(3) (SE 26.6 mm(3)) smaller left hippocampal volume. These relationships were independent of covariates including age, gender, education, labour-force status, depressive symptoms and medication, physical activity, smoking, hypertension and diabetes. While hippocampal volume declined over time, there was no evidence that dietary patterns influenced this decline. No relationships were observed between dietary patterns and right hippocampal volume.

CONCLUSIONS

Lower intakes of nutrient-dense foods and higher intakes of unhealthy foods are each independently associated with smaller left hippocampal volume. To our knowledge, this is the first human study to demonstrate associations between diet and hippocampal volume concordant with data previously observed in animal models.