Effect of flavonoids on learning, memory and neurocognitive performance: relevance and potential implications for Alzheimer's disease pathophysiology

In Vitro and In Vivo Investigations of Chromone Derivatives as Potential Multitarget-Directed Ligands: Cognitive Amelioration Utilizing a Scopolamine-Induced Zebrafish Model

Alzheimer's disease is a complex neurological disorder linked with multiple pathological hallmarks. The interrelation of therapeutic targets assists in the enhancement of cognitive decline through interference with overall neuronal transmission. We have synthesized and screened various chromone derivatives as potential multitarget-directed ligands for the effective treatment of Alzheimer's disease. The synthesized compounds exhibited multipotent activity against AChE, BuChE, MAO-B, and amyloid β aggregation. Three potent compounds, i.e., VN-3, VN-14, and VN-19 were identified that displayed remarkable activities against different targets. These compounds displayed IC50 values of 80 nM, 2.52 μM, and 140 nM against the AChE enzyme, respectively, and IC50 values of 2.07 μM, 70 nM, and 450 nM against the MAO-B isoform, respectively. VN-3 displayed potent activity against self-induced Aβ1-42 aggregation with inhibition of 58.3%. In the ROS inhibition studies, the most potent compounds reduced the intracellular ROS levels up to 80% in SH-SY5Y cells at 25 μM concentration. The compounds were found to be neuroprotective and noncytotoxic even at a concentration of 25 μM against SH-SY5Y cells. In silico studies showed that the compounds were nicely accommodated in the active sites of the receptors along with thermodynamically stable orientations. Compound VN-19 exhibited a balanced multitargeting profile against AChE, BuChE, MAO-B, and Aβ1-42 enzymes and was further evaluated for in vivo activities on the scopolamine-induced zebrafish model. VN-19 was found to ameliorate the cognitive decline in zebrafish brains by protecting them against scopolamine-induced neurodegeneration. Thus, VN-3, VN-14, and VN-19 were identified as potent multitarget-directed ligands with a balanced activity profile against different targets and can be developed as therapeutics for AD.

Blackberry extract prevents lipopolysaccharide-induced depressive-like behavior in female mice: implications for redox status, inflammation, and brain enzymes

ABSTRACTThis study evaluated the effects of Rubus sp. extract on behavioral and neurochemical parameters in female mice submitted to experimental model of depression induced by lipopolysaccharide (LPS). The results indicated that Rubus sp. extract protected against depressive-like behavior induced by LPS. Moreover, the administration of Rubus sp. extract was effective in preventing the increase in reactive species and nitrites levels, as well as the decrease in catalase activity induced by LPS in the cerebral cortex. In the serum, the Rubus sp. extract was effective in preventing the decrease in catalase activity induced by LPS. Treatment with Rubus sp. extract attenuated the increase in acetylcholinesterase activity induced by LPS in the cerebral cortex. Finally, blackberry extract also downregulated IL-1β levels in cerebral cortex. In conclusion, our findings demonstrated that treatment with Rubus sp. exerted antidepressant, antioxidant, anticholinesterase and anti-inflammatory effects in a model of depressive - like behavior induced by LPS in female mice. This highlights Rubus sp. as a potential therapeutic agent for individuals with major depressive disorder.

Effects of fruit and vegetable intake on memory and attention: a systematic review of randomized controlled trials

BACKGROUND

Memory and attention are important for daily functioning, and their function deteriorates due to aging. However, fruit and vegetable consumption are one of the protective factors against deterioration in memory and attention. This systematic review of randomized controlled trials (RCTs) aims to identify the effects of fruit and vegetable consumption on memory and attention.

METHODS

We conducted a systematic search in EBSCOhost, ProQuest, PubMed, Embase, and Web of Science from inception up to 06/09/2022. The inclusion criteria were peer-reviewed articles, fruit and vegetable intake measured using randomized controlled trials, and the outcome measures that showed the results of memory and attention scores. Two researchers independently extracted articles that met the selection criteria and evaluated the quality of each study.

RESULTS

There were 70 articles identified from the databases, of which 13 articles met the inclusion criteria and were included in this systematic review. There were 493 participants in total. The results show that consumption of fruit and vegetable intake improved memory and attention in longitudinal studies (10 to 12 weeks). Children showed improvement in immediate recall after supplementation with blueberries. Older adults required a higher dose of fruit and vegetable intake consumption to achieve significant improvement compared with children and younger adults. Furthermore, the effect of fruits and vegetables on memory showed better immediate memory recall than delayed recall.

CONCLUSION

This systematic review showed that there is an improvement in memory and attention with fruit and vegetable intake consumption. Hence, awareness of fruit and vegetable intake consumption is important to maintain cognitive health.

Protective action of Cecropia pachystachya extract and enriched flavonoid fraction against memory deficits, inflammation and oxidative damage in lipopolysaccharide challenged mice

ETHNOPHARMACOLOGICAL RELEVANCE

Cecropia pachystachya (CP) Trécul is a medicinal plant native to South and Central America with several pharmacological properties, such as anti-inflammatory and neuroprotective.

AIM OF THE STUDY

In this study, we investigated the effect of CP extract (200 mg/kg) and its enriched flavonoid fraction (EFF-CP) (50 and 100 mg/kg) in a model of lipopolysaccharide (LPS)-induced neuroinflammation.

MATERIAL AND METHODS

CP and EFF-CP were administered intragastrically for 14 days and LPS (250 μg/kg) was administered intraperitoneally from the 8th to the 14th days. LC/DAD/MS analysis showed the presence of isoorientin, orientin, and isovitexin as major compounds.

RESULTS

The results demonstrated that CP extract and EFF-CP gave protection against LPS-induced short-term and long-term memory deficits. The treatment with CP and/or EFF-CP protected against LPS-induced increases in reactive species, nitrites, total thiol and lipoperoxidation in the cerebral cortex, hippocampus and striatum. Moreover, CP and EFF-CP restored superoxide dismutase and catalase activities that had been reduced by LPS in the cerebral cortex, hippocampus and striatum. TNF-α levels were increased in the cortex, striatum and hippocampus in the LPS group, while CP treatment prevented this change in the cerebral cortex. EFF-CP decreased the levels of this cytokine in all structures analyzed at both doses.

CONCLUSION

CP extract and its EFF-CP are important therapeutic targets for the management of neuroinflammation observed in neurodegenerative diseases.

Plant-Derived Polyphenols to Prevent and Treat Oral Mucositis Induced by Chemo- and Radiotherapy in Head and Neck Cancers Management

Oral Mucositis (OM) is the most common side effect due to chemotherapy and radiotherapy, which are the conventional treatment options for head and neck cancers. OM is a severe inflammatory condition characterized by multifactorial etiopathogenesis. It further negatively affects patients' quality of life by severe impairment of normal oral functions. Consequently, it is mandatory to identify new effective therapeutic approaches to both prevent and treat OM while also avoiding any recurrence. Polyphenols recently attracted the interest of the scientific community due to their low toxicity and wide range of biological activities making them ideal candidates for several applications in the odontostomatological field, particularly against OM. This review collects the in vivo studies and the clinical trials conducted over the past 13 years evaluating the preventive and curative effects of several polyphenolic compounds towards chemo- and radiotherapy-induced OM, both when administered alone or as a plant-extracted phytocomplex. The literature fully confirms the usefulness of these molecules, thus opening the possibility of their clinical application. However, polyphenol limitations (e.g., unfavourable physicochemical properties and susceptibility to degradation) have emerged. Consequently, the interest of the scientific community should be focused on developing innovative delivery systems able to stabilize polyphenols, thus facilitating topical administration and maximizing their efficacy.

Antioxidant and anti-Alzheimer's potential of Tetragonisca angustula (Jataí) stingless bee pollen

Alzheimer's disease (AD) is considered the leading cause of dementia in the elderly worldwide. It results in progressive memory loss and impairment of cognitive and motor skills, leading to a high degree of disability and dependence. The development of AD is associated with the accumulation of senile plaques in the brain, caused by the amyloidogenic pathway of the disease. Several genetic and biochemical events are linked to AD development, with oxidative stress being one of them. Due to the scarcity of drugs aimed at treating AD, antioxidant compounds are increasingly studied as therapeutic targets for the disease. In this study, we investigate the antioxidant and anti-Alzheimer potential of the Tetragonisca angustula (Jataí) pollen extract in a Drosophila melanogaster Alzheimer's model. For this purpose, we utilized a D. melanogaster AD-like model, which expresses genes related to the amyloidogenic pathway of Alzheimer's disease. We explored the floral origin of the collected pollen, conducted phytochemical prospecting, and evaluated its antioxidant capacity in vitro. In vivo experiments involved assessing the survival and climbing ability of the D. melanogaster AD-like model with various concentrations of the pollen extract. Our findings revealed that the pollen extract of Tetragonisca angustula exhibits a significant antioxidant response and high concentrations of important phytochemicals, such as flavonoids and polyphenols. Furthermore, it enhanced the survival rate of D. melanogaster, and across all concentrations tested, it improved the climbing ability of the flies after 15 days of treatment with methanolic pollen extract. Additionally, the pollen extract reduced the neurodegeneration index in histopathological analysis. Thus, our study demonstrates the potential of Tetragonisca angustula pollen as an important subject for further investigation, aiming to isolate molecules that could potentially serve as therapeutic targets for Alzheimer's disease.

Unveiling the Therapeutic Potentials of Mushroom Bioactive Compounds in Alzheimer's Disease

Alzheimer's disease (AD) stands as a prevailing neurodegenerative condition (NDs), leading to the gradual deterioration of brain cells and subsequent declines in memory, thinking, behavior, and emotion. Despite the intensive research efforts and advances, an effective curative treatment for the disease has not yet been found. Mushrooms, esteemed globally for their exquisite flavors and abundant nutritional benefits, also hold a wealth of health-promoting compounds that contribute to improving AD health. These compounds encompass polysaccharides, proteins, lipids, terpenoids, phenols, and various other bioactive substances. Particularly noteworthy are the potent neuroprotective small molecules found in mushrooms, such as ergothioneine, erinacine, flavonoids, alkaloids, ergosterol, and melanin, which warrant dedicated scrutiny for their therapeutic potential in combating AD. This review summarizes such positive effects of mushroom bioactive compounds on AD, with a hope to contribute to the development of functional foods as an early dietary intervention for this neurodegenerative disease.

Insights into prevention mechanisms of bioactive components from healthy diets against Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease in which senile plaques, neurofibrillary tangles, insulin resistance, oxidative stress, chronic neuroinflammation, and abnormal neurotransmission are the potential mechanisms involved in its onset and development. Although it is still an intractable disorder, diet intervention has been developed as an innovative strategy for AD prevention. Some bioactive compounds and micronutrients from food, including soy isoflavones, rutin, vitamin B1, etc., have exhibited numerous neuronal health-promoting effects in both in vivo and in vitro studies. It is well known that their antiapoptotic, antioxidative, and anti-inflammatory properties prevent the neuronal or glial cells from injury or death, minimize oxidative damage, inhibit the production of proinflammatory cytokines by modulating typical signaling pathways of MAPK, NF-kβ, and TLR, and further reduce Aβ genesis and tau hyperphosphorylation. However, parts of the dietary components trigger AD-related proteins productions and inflammasome as well as inflammatory gene upregulation. This review summarized the neuroprotective or nerve damage-promoting role and underlying molecular mechanisms of flavonoids, vitamins, and fatty acids via the data from library databases, PubMed, and journal websites, which provides a comprehensive analysis of the prevention potential of these dietary components against AD.

The Potential of Flavonoids and Flavonoid Metabolites in the Treatment of Neurodegenerative Pathology in Disorders of Cognitive Decline

Flavonoids are a biodiverse family of dietary compounds that have antioxidant, anti-inflammatory, antiviral, and antibacterial cell protective profiles. They have received considerable attention as potential therapeutic agents in biomedicine and have been widely used in traditional complimentary medicine for generations. Such complimentary medical herbal formulations are extremely complex mixtures of many pharmacologically active compounds that provide a therapeutic outcome through a network pharmacological effects of considerable complexity. Methods are emerging to determine the active components used in complimentary medicine and their therapeutic targets and to decipher the complexities of how network pharmacology provides such therapeutic effects. The gut microbiome has important roles to play in the generation of bioactive flavonoid metabolites retaining or exceeding the antioxidative and anti-inflammatory properties of the intact flavonoid and, in some cases, new antitumor and antineurodegenerative bioactivities. Certain food items have been identified with high prebiotic profiles suggesting that neutraceutical supplementation may be beneficially employed to preserve a healthy population of bacterial symbiont species and minimize the establishment of harmful pathogenic organisms. Gut health is an important consideration effecting the overall health and wellbeing of linked organ systems. Bioconversion of dietary flavonoid components in the gut generates therapeutic metabolites that can also be transported by the vagus nerve and systemic circulation to brain cell populations to exert a beneficial effect. This is particularly important in a number of neurological disorders (autism, bipolar disorder, AD, PD) characterized by effects on moods, resulting in depression and anxiety, impaired motor function, and long-term cognitive decline. Native flavonoids have many beneficial properties in the alleviation of inflammation in tissues, however, concerns have been raised that therapeutic levels of flavonoids may not be achieved, thus allowing them to display optimal therapeutic effects. Dietary manipulation and vagal stimulation have both yielded beneficial responses in the treatment of autism spectrum disorders, depression, and anxiety, establishing the vagal nerve as a route of communication in the gut-brain axis with established roles in disease intervention. While a number of native flavonoids are beneficial in the treatment of neurological disorders and are known to penetrate the blood–brain barrier, microbiome-generated flavonoid metabolites (e.g., protocatechuic acid, urolithins, γ-valerolactones), which retain the antioxidant and anti-inflammatory potency of the native flavonoid in addition to bioactive properties that promote mitochondrial health and cerebrovascular microcapillary function, should also be considered as potential biotherapeutic agents. Studies are warranted to experimentally examine the efficacy of flavonoid metabolites directly, as they emerge as novel therapeutic options.

Small molecules to perform big roles: The search for Parkinson's and Huntington's disease therapeutics

Neurological motor disorders (NMDs) such as Parkinson's disease and Huntington's disease are characterized by the accumulation and aggregation of misfolded proteins that trigger cell death of specific neuronal populations in the central nervous system. Differential neuronal loss initiates the impaired motor control and cognitive function in the affected patients. Although major advances have been carried out to understand the molecular basis of these diseases, to date there are no treatments that can prevent, cure, or significantly delay the progression of the disease. In this context, strategies such as gene editing, cellular therapy, among others, have gained attention as they effectively reduce the load of toxic protein aggregates in different models of neurodegeneration. Nevertheless, these strategies are expensive and difficult to deliver into the patients' nervous system. Thus, small molecules and natural products that reduce protein aggregation levels are highly sought after. Numerous drug discovery efforts have analyzed large libraries of synthetic compounds for the treatment of different NMDs, with a few candidates reaching clinical trials. Moreover, the recognition of new druggable targets for NMDs has allowed the discovery of new small molecules that have demonstrated their efficacy in pre-clinical studies. It is also important to recognize the contribution of natural products to the discovery of new candidates that can prevent or cure NMDs. Additionally, the repurposing of drugs for the treatment of NMDs has gained huge attention as they have already been through clinical trials confirming their safety in humans, which can accelerate the development of new treatment. In this review, we will focus on the new advances in the discovery of small molecules for the treatment of Parkinson's and Huntington's disease. We will begin by discussing the available pharmacological treatments to modulate the progression of neurodegeneration and to alleviate the motor symptoms in these diseases. Then, we will analyze those small molecules that have reached or are currently under clinical trials, including natural products and repurposed drugs.

Influence of Molecular Structures on Fluorescence of Flavonoids and Their Detection in Mammalian Cells

Flavonoids are being increasingly applied for the treatment of various diseases due to their anti-cancer, anti-oxidant, anti-inflammatory, and anti-viral properties. However, it is often challenging to detect their presence in cells and tissues through bioimaging, as most of them are not fluorescent or are too weak to visualize. Here, fluorescence possibilities of nine naturally occurring analogous flavonoids have been investigated through UV/visible spectroscopy, molecular structure examination, fluorescent images in mammalian cells and their statistical analysis employing aluminum chloride and diphenylboric acid 2-aminoethyl ester as fluorescence enhancers. It is found that, in order to form a stable fluorescent complex with an enhancer, flavonoids should have a keto group at C4 position and at least one -OH group at C3 or C5 position. Additionally, the presence of a double bond at C2–C3 can stabilize extended quinonoid structure at the cinnamoyl moiety, which thereby enhances the complex stability. A possible restriction to the free rotation of ring B around C1′–C2 single bond can contribute to the further enhancement of fluorescence. Thus, these findings can act as a guide for distinguishing flavonoids capable of exhibiting fluorescence from thousands of their analogues. Finally, using this technique, flavonoids are detected in neuroblastoma cells and their time course assay is conducted via fluorescence imaging. Their cellular uptake efficiency is found to be high and differential in nature and their distribution throughout the cytoplasm is clearly detected.

Saponins and flavonoids from Bacopa floribunda plant extract exhibit antioxidant and anti-inflammatory effects on amyloid beta 1-42-induced Alzheimer's disease in BALB/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

Bacopa floribunda (BF), a locally available plant has been employed traditionally as memory enhancer in Southwestern, Nigeria. It has been utilized in traditional and Ayurvedic medicine as brain tonic for enhancing memory, anti-aging and forestalling series of psychological disorders. However, there is a dearth of scientific information on the mechanism(s) of action of important phytochemicals from BF extract on dementia.

AIM OF THE STUDY

Alzheimer's disease, the commonest form of dementia has been postulated to triple by 2050 as a result of increase in life expectancy. This study therefore assessed and compared the possible mechanism(s) of action of flavonoids and saponins from BF on Amyloid beta (Aβ1-42)-induced dementia in male BALB/c mice.

MATERIALS AND METHODS

Eighty (80) healthy BALB/c mice divided into 10 groups (n = 8) were given a single bilateral ICV injection of Aβ1-42 or normal saline. Graded doses of Saponins and flavonoids (50, 100 and 200 mg/kg) were used as treatment for 21 days. Hippocampal homogenates were assayed for the levels of antioxidants, oxidative stress and neuroinflammatory markers. In vitro antioxidant activity of flavonoids and saponins were equally assessed using standard procedures. The extent of microglial activation was quantified through immunohistochemistry procedure.

RESULTS

Aβ1-42 successfully caused a spike in hippocampal levels of MDA, IL1β, TNF-α including MPO levels and invariably decreased antioxidant activities. Likewise an increase in reactive microglia (microgliosis) was observed. However, crude saponins and flavonoids from BF were able to suppress microgliosis, oxidative stress and neuroinflammation induced by Aβ1- 42 and were observed to be more effective at higher doses of saponins (100 mg/kg and 200 mg/kg) and flavonoid (100 mg/kg).

CONCLUSIONS

Phytochemicals from BF efficiently exhibited dose dependent alleviation of some symptoms associated with Alzheimer's disease.

Protective Effect of Portulaca oleracea Extract Against Lipopolysaccharide-Induced Neuroinflammation, Memory Decline, and Oxidative Stress in Mice: Potential Role of miR-146a and miR-let 7

Neuroinflammation is an adaptive immune response to the central nervous system (CNS) injury induced by infection or toxins. MicroRNAs (miRs) showed critical roles in neuroinflammation as either proinflammatory or anti-inflammatory molecules. Interestingly, Portulaca oleracea (purslane) is an edible plant capable of ameliorating several diseases, including headache, burns, and diabetes; however, its effect on the neuroinflammation-associated miRs was not previously investigated. This study aimed to investigate the effect of aqueous purslane extract on the neuroinflammation induced by lipopolysaccharide (LPS) in mice and to identify its effect on animal cognition, oxidative stress, and expressions of miR-146a and miR-let 7. Adult mice were divided into the following groups: Normal group, LPS group, and Purslane+LPS group. Novel target recognition test, brain histopathology, and measurement of oxidative stress and inflammatory markers were performed. The results showed that LPS group exhibited significant decline in the cognitive memory, brain histopathological injury and a decrease in the number of intact neurons compared to the normal group. Furthermore, the LPS group showed a significant increase in malondialdehyde concentration, whereas superoxide dismutase and catalase activities were decreased. The LPS group also showed an increase in the inflammatory markers tumor necrosis factor-α and nuclear factor kappa B and downregulation of miR-146a and miR-let 7 expressions in the brain cells compared to the normal group, P value <.05. Interestingly, all these changes were reversed by administration of the aqueous purslane extract. In conclusion, the aqueous purslane extract protected from LPS-induced neuroinflammation and memory decline in mice through antioxidant and anti-inflammatory effect where upregulation of miR-146a and miR-1et 7 expressions was involved.

Neuroprotective effect of hesperidin and its combination with coenzyme Q10 on an animal model of ketamine-induced psychosis: behavioral changes, mitochondrial dysfunctions, and oxidative stress

Background

Psychosis is a complex mental illness divided by positive symptoms, negative symptoms, and cognitive decline. Clinically available medicines are associated with some serious side effects which limit their use. Treatment with flavonoids has been associated with delayed onset and development, decreased risk, or increased improvement of various neuropsychiatric disorders including psychosis with negligible side effects. Therefore, the present study was aimed to investigate the protective effects of hesperidin (flavonoid) alone or its combination with coenzyme Q10 against ketamine-induced psychotic symptoms in mice.

Results

Ketamine (50 mg/kg, i.p.) was given for 21 days to induce psychosis in Laca mice of either sex. Locomotor activity and stereotypic behaviors, immobility duration (forced swim test), and increased transfer latency (elevated plus maze) were performed to test the effect of hesperidin (50 mg/kg, 100 mg/kg, 200 mg/kg, p.o.) and coenzyme Q10 (20 mg/kg, 40 mg/kg, p.o.) and combination of hesperidin + coenzyme Q10 followed by biochemical and mitochondrial complexes assays. For 21 days, ketamine (50 mg/kg, i.p.) administration significantly produced increased locomotor activity and stereotypic behaviors (positive symptoms), increased immobility duration (negative symptoms) and cognitive deficits (increases transfer latency) weakens oxidative defense and mitochondrial function. Further, 21 days’ administration of hesperidin and coenzyme Q10 significantly reversed the ketamine-induced psychotic behavioral changes and biochemical alterations and mitochondrial dysfunction in the discrete areas (prefrontal cortex and hippocampus) of mice brains. The potential effect of these drugs was comparable to olanzapine treatment. Moreover, the combination of hesperidin with coenzyme Q10 and or a combination of hesperidin + coenzyme Q10 + olanzapine treatment did not produce a significant effect compared to their per se effect in ketamine-treated animals.

Conclusions

The study revealed that hesperidin alone or in combination with coenzyme Q10 could reduce psychotic symptoms and improve mitochondrial functions and antioxidant systems in mice, suggesting neuroprotective effects against psychosis.

Mental Performance and Sport: Caffeine and Co-consumed Bioactive Ingredients

The plant defence compound caffeine is widely consumed as a performance enhancer in a sporting context, with potential benefits expected in both physiological and psychological terms. However, although caffeine modestly but consistently improves alertness and fatigue, its effects on mental performance are largely restricted to improved attention or concentration. It has no consistent effect within other cognitive domains that are important to sporting performance, including working memory, executive function and long-term memory. Although caffeine's central nervous system effects are often attributed to blockade of the receptors for the inhibitory neuromodulator adenosine, it also inhibits a number of enzymes involved both in neurotransmission and in cellular homeostasis and signal propagation. Furthermore, it modulates the pharmacokinetics of other endogenous and exogenous bioactive molecules, in part via interactions with shared cytochrome P450 enzymes. Caffeine therefore enjoys interactive relationships with a wide range of bioactive medicinal and dietary compounds, potentially broadening, increasing, decreasing, or modulating the time course of their functional effects, or vice versa. This narrative review explores the mechanisms of action and efficacy of caffeine and the potential for combinations of caffeine and other dietary compounds to exert psychological effects in excess of those expected following caffeine alone. The review focusses on, and indeed restricted its untargeted search to, the most commonly consumed sources of caffeine: products derived from caffeine-synthesising plants that give us tea (Camellia sinensis), coffee (Coffea genus), cocoa (Theabroma cacao) and guaraná (Paullinia cupana), plus multi-component energy drinks and shots. This literature suggests relevant benefits to mental performance that exceed those associated with caffeine for multi-ingredient energy drinks/shots and several low-caffeine extracts, including high-flavanol cocoa and guarana. However, there is a general lack of research conducted in such a way as to disentangle the relative contributions of the component parts of these products.

Towards understanding the mechanism of action of a polyherbal formulation using a multi-pronged strategy

Herein, we investigate the cognitive effects of a traditional polyherbal formulation, Brahmi Nei (BN) for its effect on cognitive health. Network pharmacological analysis of the bioactives reported in the phytoconstituents of BN was performed by retrieving information from various databases. The in-silico predictions were experimentally validated using in vitro and in vivo models through a combination of biochemical, behavioural and molecular studies. The network pharmacological analysis of the key molecules in BN revealed their ability to modulate molecular targets implicated in memory, cognition, neuronal survival, proliferation, regulation of cellular bioenergetics and oxidative stress. Behavioral studies performed on normal adult rats administered with BN showed a significant improvement in their cognitive performance. Microarray analysis of their brain tissues exhibited an up-regulation of genes involved in oxidative phosphorylation, learning, neuronal differentiation, extension, regeneration and survival while pro-inflammatory and pro-degenerative genes were down-regulated. The oxygen consumption rate in BN-treated hippocampal cells showed a significant improvement in the bioenergetic health index when compared to untreated cells due to the mitochondrial membrane fortifying effect and anti-inflammatory property of the BN constituents. The neuroregenerative potential of BN was manifested in increase in axonal length and neurite outgrowth. Western blots and 2D gel electrophoresis revealed a reduction in pro-apoptotic proteins while increasing Akt and cyclophilin proteins. Taken together, our data reveal that BN, although traditionally used to treat anxiolytic disorders can be explored as a nutraceutical to improve neuronal health as well as a therapeutic option to treat cognitive disorders.

The Protective Action of Rubus sp. Fruit Extract Against Oxidative Damage in Mice Exposed to Lipopolysaccharide

Neuroinflammation is an event that occurs in several pathologies of brain. Rubus sp. (blackberry) is a powerful antioxidant fruit, and its extract has neuroprotective activity. The aim of this study was to investigate the blackberry extract properties on lipopolysaccharide (LPS)-induced neuroinflammation, in relation to oxidative parameters and acetylcholinesterase activity in the brain structures of mice. We also investigated interleukin-10 levels in serum. Mice were submitted to Rubus sp. extract treatment once daily for 14 days. On the fifteenth day, LPS was injected in a single dose. LPS induced oxidative brain damage and the blackberry extract demonstrated preventive effects in LPS-challenged mice. LPS administration increased reactive oxygen species levels in the cerebral cortex and striatum, as well as lipid peroxidation in the cerebral cortex. However, the blackberry extract prevented all these parameters. Furthermore, LPS decreased thiol content in the striatum and hippocampus, while a neuroprotective effect of blackberry extract treatment was observed in relation to this parameter. The blackberry extract also prevented a decrease in catalase activity in all the brain structures and of superoxide dismutase in the striatum. An increase in acetylcholinesterase activity was detected in the cerebral cortex in the LPS group, but this activity was decreased in the Rubus sp. extract group. Serum IL-10 levels were reduced by LPS, and the extract was not able to prevent this change. Finally, we observed an antioxidant effect of blackberry extract in LPS-challenged mice suggesting that this anthocyanin-rich extract could be considered as a potential nutritional therapeutic agent for preventive damage associated with neuroinflammation.

Exploring new avenues for modifying course of progression of Alzheimer's disease: The rise of natural medicine

With a constantly growing elderly population worldwide, a focus on developing efficient prevention and therapy for Alzheimer's disease (AD) seems timely and topical. Emphasis on natural medicine is increasingly popular in the search for drug candidates that are capable of preventing and treating AD related pathology, particularly where suppression of amyloid accumulation, neurofibrillary tangle formation, neuroinflammation and oxidative stress are equally significant. A number of phytochemical compounds have been shown to collectively reduce these AD hallmarks with the progression of natural drug candidates into human clinical trials. This review focuses on current research surrounding the therapies emerging within natural medicines and their related therapeutic potential for AD treatment.

Protective effects of isoquercitrin on streptozotocin-induced neurotoxicity

Alzheimer's disease (AD) is characterized by irreversible and progressive memory loss and has no effective treatment. Recently, many small molecule nature products have been identified with neuroprotective functions and shown beneficial effects to AD patients. In the current study, we thus performed a small scale screening to determine the protective effects of natural compounds on streptozotocin (STZ)‐induced neurotoxicity and Alzheimer's disease (AD). We found that a lead flavonoid compound, isoquercitrin (ISO) display the most effective anti‐cytotoxic activities via inhibiting STZ‐induced apoptosis, mitochondria dysfunction and oxidative stress. Treatment with ISO largely rescues STZ‐induced differentiation inhibition and enhances neurite outgrowth of Neuro2a (N2a) cells in vitro. Moreover, oral administration of ISO protects hippocampal neurons from STZ‐induced neurotoxicity and significantly improves the cognitive and behavioural impairment in STZ‐induced AD rats. In general, our screening identifies ISO as an effective therapeutic candidate against STZ‐induced neurotoxicity and AD‐like changes.

The botanical origin and antioxidant, anti-BACE1 and antiproliferative properties of bee pollen from different regions of South Korea

Background

Bee pollen (BP) has been used as a traditional medicine and food diet additive due to its nutritional and biological properties. The potential biological properties of bee pollen vary greatly with the botanical and geographical origin of the pollen grains. This study was conducted to characterize the botanical origin and assess the antioxidant effects of ethanol extracts of 18 different bee pollen (EBP) samples from 16 locations in South Korea and their inhibitory activities on human β-amyloid precursor cleavage enzyme (BACE1), acetylcholinesterase (AChE), human intestinal bacteria, and 5 cancer cell lines.

Methods

The botanical origin and classification of each BP sample was evaluated using palynological analysis by observing microscope slides. We measured the biological properties, including antioxidant capacity, inhibitory activities against human BACE1, and AChE, and antiproliferative activities toward five cancer cell lines, of the 18 EBPs. In addition, the growth inhibitory activities on four harmful intestinal bacteria, six lactic acid-producing bacteria, two nonpathogenic bacteria, and an acidulating bacterium were also assessed.

Results

Four samples (BP3, BP4, BP13 and BP15) were found to be monofloral and presented four dominant pollen types: Quercus palustris, Actinidia arguta, Robinia pseudoacacia, and Amygdalus persica. One sample (BP12) was found to be bifloral, and the remaining samples were considered to be heterofloral. Sixteen samples showed potent antioxidant activities with EC₅₀ from 292.0 to 673.9 μg mL^− 1. Fourteen samples presented potent inhibitory activity against human BACE1 with EC₅₀ from 236.0 to 881.1 μg mL^− 1. All samples showed antiproliferative activity toward the cancer cell lines PC-3, MCF-7, A549, NCI-H727 and AGS with IC₅₀ from 2.7 to 14.4 mg mL^− 1, 0.9 to 12.7 mg mL^− 1, 5.0 to > 25 mg mL^− 1, 2.7 to 17.7 mg mL^− 1, and 2.4 to 8.7 mg mL^− 1, respectively. In addition, total phenol and flavonoid contents had no direct correlation with antioxidant, anti-human BACE1, or antiproliferative activities.

Conclusion

Fundamentally, Korean bee pollen-derived preparations could be considered a nutritional addition to food to prevent various diseases related to free radicals, neurodegenerative problems, and cancers. The botanical and geographical origins of pollen grains could help to establish quality control standards for bee pollen consumption and industrial production.

Acute Effects of a Polyphenol-Rich Leaf Extract of Mangifera indica L. (Zynamite) on Cognitive Function in Healthy Adults: A Double-Blind, Placebo-Controlled Crossover Study

Extracts made from the leaves of the mango food plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to particularly high levels of the polyphenol mangiferin. In rodent models, oral mangiferin protects cognitive function and brain tissue from a number of challenges and modulates cerebro-electrical activity. Recent evidence has confirmed the latter effect in healthy humans following a mangiferin-rich mango leaf extract using quantitative electroencephalography (EEG). The current study therefore investigated the effects of a single dose of mango leaf extract, standardised to contain >60% mangiferin (Zynamite®), on cognitive function and mood. This study adopted a double-blind, placebo-controlled cross-over design in which 70 healthy young adults (18 to 45 years) received 300 mg mango leaf extract and a matched placebo, on separate occasions, separated by at least 7 days. On each occasion, cognitive/mood assessments were undertaken pre-dose and at 30 min, 3 h and 5 h post-dose using the Computerised Mental Performance Assessment System (COMPASS) assessment battery and the Profile of Mood States (POMS). The results showed that a single dose of 300 mg mango leaf extract significantly improved performance accuracy across the tasks in the battery, with domain-specific effects seen in terms of enhanced performance on an 'Accuracy of Attention' factor and an 'Episodic Memory' factor. Performance was also improved across all three tasks (Rapid Visual Information Processing, Serial 3s and Serial 7s subtraction tasks) that make up the Cognitive Demand Battery sub-section of the assessment. All of these cognitive benefits were seen across the post-dose assessments (30 min, 3 h, 5 h). There were no interpretable treatment related effects on mood. These results provide the first demonstration of cognition enhancement following consumption of mango leaf extract and add to previous research showing that polyphenols and polyphenol rich extracts can improve brain function.

Kaempferol and zinc gluconate mitigate neurobehavioral deficits and oxidative stress induced by noise exposure in Wistar rats

This study investigated the effects of kaempferol and zinc gluconate on neurobehavioural and oxidative stress changes in Wistar rats exposed to noise. Thirty (30) rats were randomly divided into five groups: Groups I and II were administered with deionized water (DW); Group III, kaempferol (K); Group IV, zinc gluconate (Zn); Group V, kaempferol + zinc gluconate. Groups II, III, IV, and V were subjected to noise stress (N) induced by exposing rats to 100 dB (4 h/day) for 15 days, from day 33 to day 48 after starting the drug treatments. Neuromuscular coordination, motor coordination, motor strength, sensorimotor reflex, and learning and memory, were evaluated using standard laboratory methods. Levels of nitric oxide (NO), malondialdehyde (MDA) and activities of glutathione peroxidase (GPx), catalase and superoxide dismutase (SOD) were evaluated in the hippocampus. Exposure of rats to noise, induced significant neurobehavioural deficits and oxidative stress while the combined administration of kaempferol and zinc gluconate significantly (P < 0.05) improved open-field performance, motor coordination, motor strength, sensorimotor reflex, and learning and memory. Co-administration of kaempferol and zinc gluconate ameliorated noise-induced oxidative stress as demonstrated by the significantly increased activities of GPx, catalase, and SOD, and decreased levels of NO and MDA (P < 0.05 and P < 0.01 respectively), compared to the DW + N group. Our results suggest that oxidative stress, evidenced by increased NO and MDA concentration and decreased activities of GPx, catalase and SOD, were involved in the molecular mechanism underlying neurobehavioural impairment in Wistar rats, exposed to noise stress. Single treatment of kaempferol exerted a more potent mitigative effect than zinc gluconate, while their combination produced an improved outcome.

Structure and function of the perivascular fluid compartment and vertebral venous plexus: Illumining a novel theory on mechanisms underlying the pathogenesis of Alzheimer's, cerebral small vessel, and neurodegenerative diseases

Blood dynamically and richly supplies the cerebral tissue via microvessels invested in pia matter perforating the cerebral substance. Arteries penetrating the cerebral substance derive an investment from one or two successive layers of pia mater, luminally apposed to the pial-glial basal lamina of the microvasculature and abluminally apposed to a series of aquaporin IV-studded astrocytic end feet constituting the soi-disant glia limitans. The full investment of successive layers forms the variably continuous walls of the periarteriolar, pericapillary, and perivenular divisions of the perivascular fluid compartment. The pia matter disappears at the distal periarteriolar division of the perivascular fluid compartment. Plasma from arteriolar blood sequentially transudates into the periarteriolar division of the perivascular fluid compartment and subarachnoid cisterns in precession to trickling into the neural interstitium. Fluid from the neural interstitium successively propagates into the venules through the subarachnoid cisterns and perivenular division of the perivascular fluid compartment. Fluid fluent within the perivascular fluid compartment flows gegen the net direction of arteriovenular flow. Microvessel oscillations at the central tendency of the cerebral vasomotion generate corresponding oscillations of within the surrounding perivascular fluid compartment, interposed betwixt the abluminal surface of the vessels and internal surface of the pia mater. The precise microanatomy of this most fascinating among designable spaces has eluded the efforts of various investigators to interrogate its structure, though most authors non-consensusly concur the investing layers effectively and functionally segregate the perivascular and subarachnoid fluid compartments. Enlargement of the perivascular fluid compartment in a variety of neurological disorders, including senile dementia of the Alzheimer's type and cerebral small vessel disease, may alternately or coordinately constitute a correlative marker of disease severity and a possible cause implicated in the mechanistic pathogenesis of these conditions. Venular pressures modulating oscillatory dynamic flow within the perivascular fluid compartment may similarly contribute to the development of a variety among neurological disorders. An intimate understanding of subtle features typifying microanatomy and microphysiology of the investing structures and spaces of the cerebral microvasculature may powerfully inform mechanistic pathophysiology mediating a variety of neurovascular ischemic, neuroinfectious, neuroautoimmune, and neurodegenerative diseases.

Camellia oil alleviates the progression of Alzheimer's disease in aluminum chloride-treated rats

Alzheimer's disease (AD), the most common type of dementia, is associated with oxidative stress, inflammation, and gut microbiota (GM) imbalance. Recent studies have demonstrated that camellia oil has antioxidant and anti-inflammatory activity and modulates the immune system and GM. However, the effect of camellia oil in alleviating AD pathogenesis remains unclear. An SD rat model of cognitive decline was established by the daily oral administration of aluminum chloride. The results revealed that the aluminum chloride-treated group exhibited deteriorated memory capacity and increased expression of AD-related proteins, whereas these features were mitigated in camellia oil-treated groups. Treatment with camellia oil increased antioxidant enzyme levels and decreased MDA levels. Additionally, camellia oil modulated the expression of cytokines by inhibiting RAGE/NF-κB signaling and microglial activation. Interestingly, autophagy-related proteins were increased in the camellia oil-treated groups. Moreover, camellia oil increased the abundance of probiotics in the GM. Camellia oil can reverse AD brain pathology by alleviating deficits in memory, increasing learning capacity, increasing antioxidant activity, modulating the expression of immune-related cytokines, enhancing autophagy and improving the composition of GM in aluminum chloride-treated rats, implying that AD pathogenesis may be mitigated by treatment with camellia oil through the microbiome-gut-brain axis.

Future avenues for Alzheimer's disease detection and therapy: liquid biopsy, intracellular signaling modulation, systems pharmacology drug discovery

When Alzheimer's disease (AD) disease-modifying therapies will be available, global healthcare systems will be challenged by a large-scale demand for clinical and biological screening. Validation and qualification of globally accessible, minimally-invasive, and time-, cost-saving blood-based biomarkers need to be advanced. Novel pathophysiological mechanisms (and related candidate biomarkers) - including neuroinflammation pathways (TREM2 and YKL-40), axonal degeneration (neurofilament light chain protein), synaptic dysfunction (neurogranin, synaptotagmin, α-synuclein, and SNAP-25) - may be integrated into an expanding pathophysiological and biomarker matrix and, ultimately, integrated into a comprehensive blood-based liquid biopsy, aligned with the evolving ATN + classification system and the precision medicine paradigm. Liquid biopsy-based diagnostic and therapeutic algorithms are increasingly employed in Oncology disease-modifying therapies and medical practice, showing an enormous potential for AD and other brain diseases as well. For AD and other neurodegenerative diseases, newly identified aberrant molecular pathways have been identified as suitable therapeutic targets and are currently investigated by academia/industry-led R&D programs, including the nerve-growth factor pathway in basal forebrain cholinergic neurons, the sigma1 receptor, and the GTPases of the Rho family. Evidence for a clinical long-term effect on cognitive function and brain health span of cholinergic compounds, drug candidates for repositioning programs, and non-pharmacological multidomain interventions (nutrition, cognitive training, and physical activity) is developing as well. Ultimately, novel pharmacological paradigms, such as quantitative systems pharmacology-based integrative/explorative approaches, are gaining momentum to optimize drug discovery and accomplish effective pathway-based strategies for precision medicine. This article is part of the special issue on 'The Quest for Disease-Modifying Therapies for Neurodegenerative Disorders'.

Cocoa Bean Shell-A By-Product with Nutritional Properties and Biofunctional Potential

Cocoa bean shells (CBS) are one of the main by-products from the transformation of cocoa beans, representing 10%‒17% of the total cocoa bean weight. Hence, their disposal could lead to environmental and economic issues. As CBS could be a source of nutrients and interesting compounds, such as fiber (around 50% w/w), cocoa volatile compounds, proteins, minerals, vitamins, and a large spectrum of polyphenols, CBS may be a valuable ingredient/additive for innovative and functional foods. In fact, the valorization of food by-products within the frame of a circular economy is becoming crucial due to economic and environmental reasons. The aim of this review is to look over the chemical and nutritional composition of CBS and to revise the several uses that have been proposed in order to valorize this by-product for food, livestock feed, or industrial usages, but also for different medical applications. A special focus will be directed to studies that have reported the biofunctional potential of CBS for human health, such as antibacterial, antiviral, anticarcinogenic, antidiabetic, or neuroprotective activities, benefits for the cardiovascular system, or an anti-inflammatory capacity.

An Upcoming Approach to Alzheimer's Disease: Ethnopharmacological Potential of Plant Bioactive Molecules

BACKGROUND

Neurodegenerative disorders have achieved epidemic levels in the last decades; not only the elderly but also adult individuals have been increasingly affected. Among them, Alzheimer's disease is one of the most prevalent and crippling diseases, associated with high rates of multi-morbidities and dependency. Despite the existence of a wide variety of drugs used as the symptomatic treatment, they have some side effects and toxicity, apart from their limited effectiveness. Botanical preparations have a secular use, being widely recommended for a multitude of purposes, such as for the improvement of brain health.

OBJECTIVE

The aim of the present report is to systematize the knowledge on plant-food derived bioactive molecules with promising in vitro enzymatic inhibitory activities.

RESULTS

Alkaloids, phenolic compounds and terpenes are the most studied phytochemicals, both derived from natural and commercial sources. In spite of their efficient activity as enzymatic inhibitors, the number of in vivo studies and even clinical trials have confirmed that their real bioactive potential remains scarce.

CONCLUSION

Thus, it is of the utmost importance to deepen knowledge in this area, once those relevant and informative tools can significantly contribute to the promising advances in the field of Alzheimer's disease treatment.

Chromone and donepezil hybrids as new multipotent cholinesterase and monoamine oxidase inhibitors for the potential treatment of Alzheimer's disease

A series of chromone and donepezil hybrids were designed, synthesized, and evaluated as multipotent cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors for the potential therapy of Alzheimer's disease (AD). In vitro studies showed that the great majority of these compounds exhibited potent inhibitory activity toward BuChE and AChE and clearly selective inhibition for hMAO-B. In particular, compound 5c presented the most balanced potential for ChE inhibition (BuChE: IC₅₀ = 5.24 μM; AChE: IC₅₀ = 0.37 μM) and hMAO-B selectivity (IC₅₀ = 0.272 μM, SI = 247). Molecular modeling and kinetic studies suggested that 5c was a mixed-type inhibitor, binding simultaneously to peripheral and active sites of AChE. It was also a competitive inhibitor, which occupied the substrate and entrance cavities of MAO-B. Moreover, compound 5c could penetrate the blood-brain barrier (BBB) and showed low toxicity to rat pheochromocytoma (PC12) cells. Altogether, these results indicated that compound 5c might be a hopeful multitarget drug candidate with possible impact on Alzheimer's disease therapy.

Neuroprotective role of naringenin against methylmercury induced cognitive impairment and mitochondrial damage in a mouse model

Human exposure to organomercurials like methylmercury (MeHg) may occur by consumption of contaminated seafood, affecting various vital organs especially, brain contributing to neuro disorders. The citrus flavanone, naringenin (NAR) has shown strong antioxidant and anti-inflammatory effects and therefore may exert cytoprotective effect against xenobiotic agents. Herein, we investigated the neuroprotective role of NAR against MeHg induced functional changes in mitochondria, neuronal cell death and cognitive impairment in a mouse model. A neurotoxic dose of MeHg (4 mg/kg.b.wt.) was administered orally to mice for 15 days. This resulted in the reduction of GSH and GST, an increase in mitochondrial DNA damage and memory impairment. On the contrary, NAR pre-treatment (100 mg/kg.b.wt.), helped in lowering the oxidative burden which in turn maintained mitochondrial function and prevented induced neuronal cell death, ultimately improving the cognitive impairment. As MeHg intoxication occurs chronically, consumption of the dietary components rich in NAR may have its positive human health impact, ultimately improving the quality of life.

The New Application of UHPLC-DAD-TOF/MS in Identification of Inhibitors on β-Amyloid Fibrillation From Scutellaria baicalensis

Literary evidence depicts that aggregated β-amyloid (Aβ) leads to the pathogenesis of Alzheimer's disease (AD). Although many traditional Chinese medicines (TCMs) are effective in treating neurodegenerative diseases, there is no effective way for identifying active compounds from their complicated chemical compositions. Instead of using a traditional herbal separation method with low efficiency, we herein apply UHPLC-DAD-TOF/MS for the accurate identification of the active compounds that inhibit the fibrillation of Aβ (1-42), via an evaluation of the peak area of individual chemical components in chromatogram, after incubation with an Aβ peptide. Using the neuroprotective herbal plant Scutellaria baicalensis (SB) as a study model, the inhibitory effect on Aβ by its individual compounds, were validated using the thioflavin-T (ThT) fluorescence assay, biolayer interferometry analysis, dot immunoblotting and native gel electrophoresis after UHPLC-DAD-TOF/MS analysis. The viability of cells after Aβ (1-42) incubation was further evaluated using both the tetrazolium dye (MTT) assay and flow cytometry analysis. Thirteen major chemical components in SB were identified by UHPLC-DAD-TOF/MS after incubation with Aβ (1-42). The peak areas of two components from SB, baicalein and baicalin, were significantly reduced after incubation with Aβ (1-42), compared to compounds alone, without incubation with Aβ (1-42). Consistently, both compounds inhibited the formation of Aβ (1-42) fibrils and increased the viability of cells after Aβ (1-42) incubation. Based on the hypothesis that active chemical components have to possess binding affinity to Aβ (1-42) to inhibit its fibrillation, a new application using UHPLC-DAD-TOF/MS for accurate identification of inhibitors from herbal plants on Aβ (1-42) fibrillation was developed.

Multidirectional insights into the biochemical and toxicological properties of Bougainvillea glabra (Choisy.) aerial parts: A functional approach for bioactive compounds

The current research work was conducted in order to probe into the biochemical and toxicological characterisation of methanol and dichloromethane (DCM) extracts of Bougainvillea glabra (Choisy.) aerial parts. Biological fingerprints were assessed for in vitro antioxidant, key enzyme inhibitory and cytotoxicity potential. Total bioactive contents were determined spectrophotometrically and the secondary metabolite components of methanol extract was assessed by UHPLC mass spectrometric analysis. The antioxidant capabilities were evaluated via six different in vitro antioxidant assays namely DPPH, ABTS (free radical scavenging), FRAP, CUPRAC (reducing antioxidant power), phosphomolybdenum (total antioxidant capacity) and ferrous chelating activity. Inhibition potential against key enzymes urease, α-glucosidase and cholinesterases were also determined. Methanol extract exhibited higher phenolic (24.01 mg GAE/g extract) as well as flavonoid (41.51 mg QE/g extract) contents. Phytochemical profiling of methanol extract identified a total of twenty secondary metabolites and the major compounds belonged to flavonoids, phenolics and alkaloid derivatives. The findings of antioxidant assays revealed the methanol extract to exhibit stronger antioxidant (except phosphomolybdenum) activities. Similarly, the methanol extract showed highest butyrylcholinesterase and urease inhibition. The DCM extract was most active for phosphomolybdenum and α-glucosidase inhibition assays. Moreover, both extracts exhibited significant cytotoxic potential against five (MCF-7, MDA-MB-231, CaSki, DU-145, and SW-480) human carcinoma cell lines with half maximal inhibitory concentration values of 22.09 to 257.2 μg/mL. Results from the present study highlighted the potential of B. glabra aerial extracts to be further explored in an endeavour to discover novel phytotherapeutics as well as functional ingredients.

Phytochemicals for Improving Aspects of Cognitive Function and Psychological State Potentially Relevant to Sports Performance

Subjective alertness and optimal cognitive function, including in terms of attention, spatial/working memory and executive function, are intrinsic to peak performance in many sports. Consumption of a number of plant-derived 'secondary metabolite' phytochemicals can modulate these psychological parameters, although there is a paucity of evidence collected in a sporting context. The structural groups into which these phytochemicals fall-phenolics, terpenes and alkaloids-vary in terms of the ecological roles they play for the plant, their toxicity and the extent to which they exert direct effects on brain function. The phenolics, including polyphenols, play protective roles in the plant, and represent a natural, benign component of the human diet. Increased consumption has been shown to improve cardiovascular function and is associated with long-term brain health. However, whilst short-term supplementation with polyphenols has been shown to consistently modulate cerebral blood-flow parameters, evidence of direct effects on cognitive function and alertness/arousal is currently comparatively weak. Terpenes play both attractant and deterrent roles in the plant, and typically occur less frequently in the diet. Single doses of volatile monoterpenes derived from edible herbs such as sage (Salvia officinalis/lavandulaefolia) and peppermint (Mentha piperita), diterpene-rich Ginkgo biloba extracts and triterpene-containing extracts from plants such as ginseng (Panax ginseng/quinquefolius) and Bacopa monnieri have all been shown to enhance relevant aspects of cognitive function and alertness. The alkaloids play toxic defensive roles in the plant, including via interference with herbivore brain function. Whilst most alkaloids are inappropriate in a sporting context due to toxicity and legal status, evidence suggests that single doses of nicotine and caffeine may be able to enhance relevant aspects of cognitive function and/or alertness. However, their benefits may be confounded by habituation and withdrawal effects in the longer term. The efficacy of volatile terpenes, triterpene-rich extracts and products combining low doses of caffeine with other phytochemicals deserves more research attention.

Exploring cocoa properties: is theobromine a cognitive modulator?

Nutritional qualities of cocoa have been acknowledged by several authors; a particular focus has been placed on its high content of flavanols, known for their excellent antioxidant properties and subsequent protective effect on cardio- and cerebrovascular systems as well as for neuromodulatory and neuroprotective actions. Other active components of cocoa are methylxanthines (caffeine and theobromine). Whereas the effects of caffeine are extensively researched, the same is not the case for theobromine; this review summarizes evidence on the effect of theobromine on cognitive functions. Considering animal studies, it can be asserted that acute exposition to theobromine has a reduced and delayed nootropic effect with respect to caffeine, whereas both animal and human studies suggested a potential neuroprotective action of long-term assumption of theobromine through a reduction of Aβ amyloid pathology, which is commonly observed in Alzheimer's disease patients' brains. Hence, the conceivable action of theobromine alone and associated with caffeine or other cocoa constituents on cognitive modulation is yet underexplored and future studies are needed to shed light on this promising molecule.

Effect of a Strawberry and Spinach Dietary Supplement on Spatial Learning in Early and Late Middle-Aged Female Rats

The present experiment sought to determine the effect of an eight-week, high antioxidant, whole-foods dietary supplement on Morris Water Maze performance in early and late middle-aged female rats. To improve ecological validity over past experimental studies, rats in the current study received antioxidants by consuming freeze-dried organic strawberries and spinach rather than by being given food extracts or antioxidant injections. Latency and path length measures both indicated that late middle-aged rats fed the high antioxidant diet performed on a par with the younger animals earlier in training than their standard diet counterparts (p < 0.05). Superior performance was not due to improved fitness in the antioxidant-supplemented rats. Thus, our model showed that a high antioxidant diet of relatively short duration mitigated the mild cognitive decline that was seen in control animals during the developmental period of late middle-age. The current results offer support for the promising role of dietary antioxidants in maintaining cognitive health in normal aging and extend past findings to females, who have been relatively neglected in experimental investigations. Moreover, the current model suggests that the period of transition from early to late middle age is a promising target for dietary intervention in healthy adults.

The Effects of Flavonoids on Cardiovascular Health: A Review of Human Intervention Trials and Implications for Cerebrovascular Function

Research has suggested a number of beneficial effects arising from the consumption of dietary flavonoids, found in foods such as cocoa, apples, tea, citrus fruits and berries on cardiovascular risk factors such as high blood pressure and endothelial dysfunction. These effects are thought to have a significant impact upon both vascular and cerebrovascular health, ultimately with the potential to prevent cardiovascular and potentially neurodegenerative disease with a vascular component, for example vascular dementia. This review explores the current evidence for the effects of flavonoid supplementation on human endothelial function and both peripheral and cerebral blood flow (CBF). Evidence presented includes their potential to reduce blood pressure in hypertensive individuals, as well as increasing peripheral blood perfusion and promoting CBF in both healthy and at-risk populations. However, there is great variation in the literature due to the heterogeneous nature of the randomised controlled trials conducted. As such, there is a clear need for further research and understanding within this area in order to maximise potential health benefits.

Deep eutectic solvents used as extraction solvent for the determination of flavonoids from Camellia oleifera flowers by high-performance liquid chromatography

INTRODUCTION

Camellia oleifera flowers are rich in flavonoids, but there has been little attention on their application. A simple and reliable method for determining the content of flavonoids in C. oleifera flowers would be very helpful for the utilisation of agriculture resources.

OBJECTIVE

To develop an efficient analytical method for the determination of flavonoids in C. oleifera flowers by high-performance liquid chromatography-ultraviolet (HPLC-UV) detection.

METHODOLOGY

Preparing an environmentally-friendly and effective solvent - deep eutectic solvents (DESs) - for compound extraction. Then investigating the influential factors of ultrasound-assisted extraction with DESs by the Box-Behnken design combined with response surface methodology.

RESULTS

DES-5 synthesised with choline chloride and lactic acid (1:2) acquired excellent extractability for four flavonoids (quercetin 3-O-rhamnoside, kaempferol 3-O-rhamnoside and their aglycones) with different polarity. The proposed method, which could simultaneously determine four flavonoids with HPLC-UV detection for the first time, displays satisfactory recovery yields and high precision with inter-day relative standard deviation lower than 5.80%.

CONCLUSION

DESs could be promising solvents for efficiently and selectively extracting bioactive compounds from plant materials, and the analytical method for flavonoids of C. oleifera flowers could provide reference value for its application and be used in other plant resources.

Changes of hippocampus proteomic profiles after blueberry extracts supplementation in APP/PS1 transgenic mice

Objective: To examine protein changes in the hippocampus of APP/PS1 transgenic mice after blueberry extracts (BB) intervention.Methods: Eight APP/PS1 transgenic mice were randomly assigned to Alzheimer's disease (AD)+BB group (n=4) and AD+control group (n=4). After a 16-week treatment, 2-DE and MALDI-TOF-MS were used to compare the proteomic profiles of the hippocampus in the two groups and Western blot was used to confirm the important differentially expressed proteins.Results: Twelve proteins were differentially expressed between the two groups. Nine of them were identified. Cytochrome b-c1 complex subunit 6, beta-actin, dynamin 1, and heat shock cognate 71 were up-regulated in AD+BB group, while a-enolase, stress-induced-phosphoprotein 1, malate dehydrogenase (MDH), MDH 1, and T-complex protein 1 subunit beta were down-regulated, respectively. Importantly, some of the identified proteins (e.g. dynamin 1) are known to be involved in cognitive impairment. Western blot analysis of hippocampus dynamin 1 expression confirmed the proteomic findings.Conclusions: The consumption of BB modulates the expression of proteins that are linked to the improvements of cognitive dysfunction in hippocampus of APP/PS1 transgenic mice.

A review on flavonoid-based scaffolds as multi-target-directed ligands (MTDLs) for Alzheimer's disease

Alzheimer's disease (AD), the most common form of dementia, is a multifactorial neurodegenerative disease. The target enzymes inhibition including cholinesterase, beta-secretase, monoamine oxidase and inhibition of amyloid-β aggregation as well as oxidative stress and metal chelation play an important role in the pathogenesis of AD. Chroman-4-one scaffold with benzo-γ-pyrone network is a privileged structure in organic synthesis and drug design. A large number of research has been carried out on modified naturally occurring chromanone scaffolds and/or synthesized new analogues, to obtain effective drugs for AD management. The present review summarizes aspects related to the multi-target-directed ligands (MTDLs) strategy in enzyme targets modulation performed with natural and synthesized chroman-4-one-based structures to look at their potential in the management of multifactorial Alzheimer's disease.

Investigation on the Role of BDNF in the Benefits of Blueberry Extracts for the Improvement of Learning and Memory in Alzheimer's Disease Mouse Model

BACKGROUND

Blueberry (BB) can provide a wide range of antioxidant benefits for AD. There is evidence that BB extracts could improve brain functions. However, the details are still unknown.

OBJECTIVE

In the present study, we aimed to investigate the possible mechanism involved in the improvement of learning and memory capacity from BB extracts in AD.

METHODS

APP/PS1 transgenic mice were fed BB extracts for 16 weeks. The capacity of learning and memory was assessed by Morris water maze (MWM) test, and long-term potentiation (LTP) was determined to evaluate hippocampal neuronal plasticity at the end of administration. Pathological changes in the brain were observed, and the expressions of brain-derived neurotrophic factor (BDNF) and extracellular signal-related kinase (ERK1/2) were determined to explore the mechanism of BB extract-induced benefits.

RESULTS

AD mice exhibited more difficulties to learn and remember the exact position of the platform in the MWM test. The data showed that AD mice lacked effective learning in the platform search. In contrast, AD mice exhibited better performance both in the training phase and probe test of MWM after the BB treatment. Moreover, LTP was enhanced and the neuron loss was alleviated with BB treatment, while we did not find any obvious effect on the elimination of amyloid-β. In the AD mice, the expression of ERK1/2 was significantly increased (p < 0.05), while the level of BDNF was decreased (p < 0.05).

CONCLUSIONS

BB treatment was beneficial for the improvement of learning and memory of AD, and these effects might be related to the regulation of BDNF.

Cognitive-Enhancing Effects of a Polyphenols-Rich Extract from Fruits without Changes in Neuropathology in an Animal Model of Alzheimer's Disease

No effective preventive treatment is available for age-related cognitive decline and Alzheimer's disease (AD). Epidemiological studies indicate that a diet rich in fruit is associated with cognitive improvement. It was thus proposed that high polyphenol concentrations found in berries can prevent cognitive impairment associated with aging and AD. Therefore, the Neurophenols project aimed at investigating the effects of a polyphenolic extract from blueberries and grapes (PEBG) in the triple-transgenic (3xTg-AD) mouse model of AD, which develops AD neuropathological markers, including amyloid-β plaques and neurofibrillary tangles, leading to memory deficits. In this study, 12-month-old 3xTg-AD and NonTg mice were fed a diet supplemented with standardized PEBG (500 or 2500 mg/kg) for 4 months (n = 15-20/group). A cognitive evaluation with the novel object recognition test was performed at 15 months of age and mice were sacrificed at 16 months of age. We observed that PEBG supplementation with doses of 500 or 2500 mg/kg prevented the decrease in novel object recognition observed in both 15-month-old 3xTg-AD mice and NonTg mice fed a control diet. Although PEBG treatment did not reduce Aβ and tau pathologies, it prevented the decrease in mature BDNF observed in 16-month-old 3xTg-AD mice. Finally, plasma concentrations of phenolic metabolites, such as dihydroxyphenyl valerolactone, a microbial metabolite of epicatechin, positively correlated with memory performances in supplemented mice. The improvement in object recognition observed in 3xTg-AD mice after PEBG administration supports the consumption of polyphenols-rich extracts to prevent memory impairment associated with age-related disease, without significant effects on classical AD neuropathology.

Attenuation of neurobehavioral and neurochemical abnormalities in animal model of cognitive deficits of Alzheimer's disease by fermented soybean nanonutraceutical

The present study was performed to evaluate the efficacy of nanonutraceuticals (NN) for attenuation of neurobehavioral and neurochemical abnormalities in Alzheimer's disease. Solid-state fermentation of soybean with Bacillus subtilis was performed to produce different metabolites (nattokinase, daidzin, genistin and glycitin and menaquinone-7). Intoxication of rats with colchicine caused impairment in learning and memory which was demonstrated in neurobehavioral paradigms (Morris water maze and passive avoidance) linked with decreased activity of acetylcholinesterase (AChE). NN treatment led to a significant increase in TLT in the retention trials as compared to acquisition trial TLT suggesting an improved learning and memory in rats. Further, treatment of NN caused an increase in the activity of AChE (42%), accompanied with a reduced activity of glutathione (42%), superoxide dismutase (43%) and catalase (41%). It also decreased the level of lipid peroxidation (28%) and protein carbonyl contents (30%) in hippocampus as compared to those treated with colchicine alone, suggesting a possible neuroprotective efficacy of NN. Interestingly, in silico studies also demonstrated an effective amyloid-β and BACE-1 inhibition activity. These findings clearly indicated that NN reversed colchicine-induced behavioral and neurochemical alterations through potent antioxidant activity and could possibly impart beneficial effects in cognitive defects associated with Alzheimer's disease.

The impact of blackcurrant juice on attention, mood and brain wave spectral activity in young healthy volunteers

There is a growing body of evidence from randomized controlled trials which indicates that consumption of berries has a positive effect upon the cognitive function of healthy adults. It has been recommended that studies combining cognitive and physiological measures be undertaken in order to strengthen the evidence base for the putative effects of flavonoid consumption on cognitive outcomes. This pilot study utilized a randomized, double-blind and placebo controlled crossover design to assess the influence of the acute administration of anthocyanin-rich blackcurrant juice, standardized at 500 mg of polyphenols, on mood and attention. Additionally, this trial used electroencephalography (EEG) to assess if any changes in cognitive performance are associated with changes in localized prefrontal cortex neuronal activity in nine healthy young adults. Outcomes from the pilot EEG data highlight an anxiolytic effect of the consumption of a single serve blackcurrant juice, as indexed by a suppression of α spectral power, and an increase in the slow wave δ and θ spectral powers. There was also an indication of greater alertness and lower fatigue, as indexed by an increase in β power and suppression of α spectral power. Outcomes from the CogTrack™ system indicated a small acute increase in reaction times during the digit vigilance task.

Targeting NAD+ degradation: The therapeutic potential of flavonoids for Alzheimer's disease and cognitive frailty

Flavonoids are efficacious candidates as pharmaceuticals or nutraceuticals in the treatment of Alzheimer's disease (AD), aging and other age-related chronic inflammatory diseases. Natural flavonoids reduce pathological hallmarks, extracellular amyloid deposits and neurofibrillary tangles by mediating amyloid precursor protein (APP) processing, Aβ accumulation and tau pathology. The antioxidant and anti-inflammatory actions as well as modulation of sirtuins and telomeres are also involved in the amelioration of aging, neurodegeneration and other age-related diseases. Recently, some flavonoids were shown to inhibit poly (ADP-ribose) polymerases (PARPs) and cyclic ADP-ribose (cADP) synthases (CD38 and CD157), elevate intracellular nicotinamide adenine dinucleotide⁺ (NAD⁺) levels and activate NAD⁺ dependent sirtuin -mediated signaling pathways. We summarized how flavonoids reduce the degradation of NAD⁺ with an emphasis on the mechanisms through which flavonoids affect the NAD⁺-sirtuin axis to protect against AD. Aging and age-related diseases as well as a decline in the physiological reserve are the risk factors for cognitive frailty. Flavonoids with multiple therapeutic targets may also be potential candidates for the prevention and treatment of cognitive frailty.

Therapeutic impact of grape leaves polyphenols on certain biochemical and neurological markers in AlCl3-induced Alzheimer's disease

Alzheimer's disease (AD) is a grave and prevailing neurodegenerative disease, characterized by slow and progressive neurodegeneration in different brain regions. Aluminum (Al) is a potent and widely distributed neurotoxic metal, implicated in the neuropathogenesis of AD. This study aimed to evaluate the possible neurorestorative potential of Vitis vinifera Leaves Polyphenolic (VLP) extract in alleviating aluminum chloride (AlCl₃)-induced neurotoxicity in male rats. AlCl₃ neurotoxicity induced a significant decrease in brain/serum acetylcholine (ACh) contents and serum dopamine (DA) levels, along with a significant increment of brain/serum acetylcholinesterase (AChE) activities. In addition, Al treatment resulted in significantly decreased serum levels of both total antioxidant capacity (TAC) and brain-derived neurotrophic factor (BDNF), and significantly increased serum levels of both interleukin-6 (IL-6) and total homocysteine (tHcy), as compared to control. Behavioral alterations, assessed by the T-maze test, showed impaired cognitive function. Furthermore, AD-brains revealed an increase in DNA fragmentation as evidenced by comet assay. AlCl₃ induction also caused histopathological alterations in AD-brain. Treatment of AD-rats with VLP extract (100mg/kg body weight/day) improved neurobehavioral changes, as evidenced by the improvement in brain function, as well as, modulation of most biochemical markers, and confirmed by T-maze test, the histopathological study of the brain and comet assay. The current work indicates that the VLP extract has neuroprotective, antioxidative, anti-inflammatory, and anti-amnesic activities against AlCl₃-induced cerebral damages and neurocognitive dysfunction.