Beyond antioxidants: the cellular and molecular interactions of flavonoids and how these underpin their actions on the brain

The consumption of flavonoid-rich foods and beverages has been suggested to limit the neurodegeneration associated with a variety of neurological disorders and to prevent or reverse normal or abnormal deteriorations in cognitive performance. Flavonoids mediate these effects via a number of routes, including a potential to protect neurons against injury induced by neurotoxins, an ability to suppress neuroinflammation and a potential to promote memory, learning and cognitive function. Originally, it was thought that such actions were mediated by the antioxidant capacity of flavonoids. However, their limited absorption and their low bioavailability in the brain suggest that this explanation is unlikely. Instead, this multiplicity of effects appears to be underpinned by three separate processes: first, through their interactions with important neuronal and glial signalling cascades in the brain, most notably the phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase pathways that regulate pro-survival transcription factors and gene expression; second, through an ability to improve peripheral and cerebral blood flow and to trigger angiogenesis and neurogenesis in the hippocampus; third, by their capacity to directly react with and scavenge neurotoxic species and pro-inflammatory agents produced in the brain as a result of both normal and abnormal brain ageing. The present review explores the potential inhibitory or stimulatory actions of flavonoids within these three systems and describes how such interactions are likely to underlie neurological effects

Why are Americans against eating insects?

Some scientists are worried about food shortages in the future as the population grows, and food production is not growing fast enough to keep up (Tao and Li 2018). This has led many scientists to look at insects as potential replacements or supplements to current livestock because insects are much more efficient, cheap, and environmentally friendly to raise than traditional live stock and have more protein per mass (Hartmann and Siegrist 2017). However, the trouble is to get Americans and other Westerners to accept insects into their diet because they are the largest consumers of meat in the world, and to be able to do that we need to understand the Western aversion to eating insects. (Schuursman 2014) According to my research, the most likely factors that cause United States citizens to have an aversion to eating insects are because they see insects as pests to their crops, because insects look alien and scary to them, and, or because eating insects is not convenient, cheap, or socially accepted (Bellisle 2006). My study showed that there is a positive relationship between interest in trying insects and likelihood of buying them from the store, between not seeing insects as a pest and interest in trying insects, someone’s adventurousness and their openness to trying new foods, and the likelihood of eating insects if it was socially accepted and interest in trying insects. My results are important because they show that there are several identifiable factors that determine whether or not someone is interested in trying insects. This shows that by meeting these factors, we can get Westerners to at the very least try insects

How Cultural Perceptions and Food Preparation Affect Westerners View of Insects as Food

There has been a recent push to encourage westerners to introduce insects into their diets. Traditional arguments that stress environmental and nutritional benefits have been largely unsuccessful. This not because people simply find insects distasteful; what people view as an acceptable food choice is culturally dependent, and foods made from novel and unfamiliar ingredients or tools are met with apprehension. What is less known is why insects are viewed as an unacceptable food source in western society. It has been suggested that westerners disgust towards insects is that insects are perceived of as contaminants and as vectors of disease. If westerners are unwilling to eat insects, or food prepared with insects because they are viewed as unhygienic, then we should expect individuals who are less concerned with hygiene to be more willing to eat insects, or food prepared with insects. When surveyed on their hygiene and their willingness to try food prepared using insects, participants that were less concerned with personal hygiene were more willing to eat food made with insects. In order to convince people to introduce insects into their diet one must know why people are so uneager to consume insects

The impact of fruit flavonoids on memory and cognition

There is intense interest in the studies related to the potential of phytochemical-rich foods to prevent age-related neurodegeneration and cognitive decline. Recent evidence has indicated that a group of plant-derived compounds known as flavonoids may exert particularly powerful actions on mammalian cognition and may reverse age-related declines in memory and learning. In particular, evidence suggests that foods rich in three specific flavonoid sub-groups, the flavanols, anthocyanins and/or flavanones, possess the greatest potential to act on the cognitive processes. This review will highlight the evidence for the actions of such flavonoids, found most commonly in fruits, such as apples, berries and citrus, on cognitive behaviour and the underlying cellular architecture. Although the precise mechanisms by which these flavonoids act within the brain remain unresolved, the present review focuses on their ability to protect vulnerable neurons and enhance the function of existing neuronal structures, two processes known to be influenced by flavonoids and also known to underpin neuro-cognitive function. Most notably, we discuss their selective interactions with protein kinase and lipid kinase signalling cascades (i.e. phosphoinositide-3 kinase/Akt and mitogen-activated protein kinase pathways), which regulate transcription factors and gene expression involved in both synaptic plasticity and cerebrovascular blood flow. Overall, the review attempts to provide an initial insight into the potential impact of regular flavonoid-rich fruit consumption on normal or abnormal deteriorations in cognitive performance

The American dream and the margins in twentieth century fiction

Dissertation advisor: Dr. Andrew Hoberek.Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 16, 2010).Dissertations, Academic -- University of Missouri--Columbia -- English.The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Ph.D. University of Missouri--Columbia 2009.Vita.While the American Dream is an oft trod, even clich'ed, terrain in literary criticism, discourse around the topic tends to rely on a dichotomized discourse of celebration or critique. This tendency is a result of understanding the American Dream in literature to be merely a thematic concern. This dissertation approaches the American Dream as a narrative structure whose aim is to mediate symbolic citizenship between the poles of stable social order and innovative progress. Thus, the texts covered are characterized by narrative doubling, with characters possessing normative American attributes (money, a good job, a stable home life) paired with marginalized opposites who possess a more fluid, creative, and multiplicitous sense of identity. The narrative, then, becomes the means by which the models of Americanness represented by these doubles become merged into an effective model of American citizenship. This narrative line is traced through F. Scott Fitzgerald's The Great Gatsby, Howards Hawk's film Scarface, Jack Kerouac's On the Road, and Amy Tan's the Joy Luck Club

GP perspectives on hospital discharge letters : an interview and focus group study

Background: Written discharge communication following inpatient or outpatient clinic discharge is essential for communicating information to the GP, but GPs’ opinions on discharge communication are seldom sought. Patients are sometimes copied into this communication, but the reasons for this variation, and the resultant effects, remain unclear. Aim: To explore GP perspectives on how discharge letters can be improved in order to enhance patient outcomes. Design & setting: The study used narrative interviews with 26 GPs from 13 GP practices within the West Midlands, England. Method: Interviews were transcribed and data were analysed using corpus linguistics (CL) techniques. Results Elements pivotal to a successful letter were: diagnosis, appropriate follow-up plan, medication changes and reasons, clinical summary, investigations and/or procedures and outcomes, and what information has been given to the patient. GPs supported patients receiving discharge letters and expounded a number of benefits of this practice; for example, increased patient autonomy. Nevertheless, GPs felt that if patients are to receive direct discharge letter copies, modifications such as use of lay language and avoidance of acronyms may be required to increase patient understanding. Conclusion: GPs reported that discharge letters frequently lacked content items they assessed to be important; GPs highlighted that this can have subsequent ramifications on resources and patient experiences. Templates should be devised that put discharge letter elements assessed to be important by GPs to the forefront. Future research needs to consider other perspectives on letter content, particularly those of patients

Hearing in dementia: defining deficits and assessing impact

The association between hearing impairment and dementia has emerged as a major public health challenge, with significant opportunities for earlier diagnosis, treatment and prevention. However, the nature of this association has not been defined. We hear with our brains, particularly within the complex soundscapes of everyday life: neurodegenerative pathologies target the auditory brain and are therefore predicted to damage hearing function early and profoundly. Here I present evidence for this proposition, based on structural and functional features of auditory brain organisation that confer vulnerability to neurodegeneration, the extensive, reciprocal interplay between ‘peripheral’ and ‘central’ hearing dysfunction, and recently characterised auditory signatures of canonical neurodegenerative dementias (Alzheimer’s disease and frontotemporal dementia). In chapter 3, I examine pure tone audiometric thresholds in AD and FTD syndromes and explore the functional interplay between the auditory brain and auditory periphery by assessing the contribution of auditory cognitive factors on pure tone detection. In chapter 4, I develop this further by examining the processing of degraded speech signals, leveraging the increased importance of top-down integrative and predictive mechanisms on resolving impoverished bottom-up sensory encoding. In chapter 5, I use a more discrete test of phonological processing to focus in on a specific brain region that is an early target in logopenic aphasia, to explore the potential of auditory cognitive tests as disease specific functional biomarkers. Finally, in chapter 6, I use auditory symptom questionnaires to capture real-world hearing in daily life amongst patients with dementia as well as their carers and measure how this correlates with audiometric performance and degraded speech processing. I call for a clinical assessment of real-world hearing in these diseases that moves beyond pure tone perception to the development of novel auditory ‘cognitive stress tests’ and proximity markers for the early diagnosis of dementia and management strategies that harness retained auditory plasticity

Acute effects of Hibiscus sabdariffa calyces on postprandial blood pressure, vascular function, blood lipids, biomarkers of insulin resistance and inflammation in humans

The acute impact of Hibiscus sabdariffa calyces (HSC) extract on postprandial vascular function and other cardiometabolic risk factors have not been studied previously. This study investigated the acute impact of HSC extract consumption on blood pressure (BP), vascular function and other cardiometabolic risk markers. Twenty-five men with 1% to 10% cardiovascular disease (CVD) risk (determined by QRISK 2) were randomised to consume either 250 mL of the aqueous extract of HSC or water with breakfast in a randomised, controlled, single-blinded, 2-meal cross-over study (ClinicalTrials.gov, NTC02165553) with a two weeks washout period between study days. BP was measured at baseline and hourly for 4 h. Flow mediated dilatation (FMD) of the branchial artery was measured at baseline, 2 and 4 h post intervention drink consumption. Acute consumption of aqueous extract of HSC caused a significant increase in % FMD ( < 0.001), a non-significant decrease in systolic BP (SBP) and diastolic BP (DBP); non-significant increase in urinary and plasma nitric oxide (NOx) and reduced response of serum glucose, plasma insulin, serum triacylglycerol and C-reactive protein (CRP) levels; significant ( = 0.026) improvement in the area under systemic antioxidant response curve (0 to 2 h); no significant changes in arterial stiffness following the acute consumption of the extract of HSC. Gallic acid, 4-O-methylgallic acid, 3-O-methylgallic acid and hippuric acid reached a maximum plasma concentration at 1 to 2 h post consumption of the extract of HSC. The extract of HSC improved postprandial vascular function and may be a useful dietary strategy to reduce endothelial dysfunction and CVD risk, although this requires confirmation

Platelet-mediated metabolism of the common dietary flavonoid, quercetin.

BACKGROUND: Flavonoid metabolites remain in blood for periods of time potentially long enough to allow interactions with cellular components of this tissue. It is well-established that flavonoids are metabolised within the intestine and liver into methylated, sulphated and glucuronidated counterparts, which inhibit platelet function. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate evidence suggesting platelets which contain metabolic enzymes, as an alternative location for flavonoid metabolism. Quercetin and a plasma metabolite of this compound, 4'-O-methyl quercetin (tamarixetin) were shown to gain access to the cytosolic compartment of platelets, using confocal microscopy. High performance liquid chromatography (HPLC) and mass spectrometry (MS) showed that quercetin was transformed into a compound with a mass identical to tamarixetin, suggesting that the flavonoid was methylated by catechol-O-methyl transferase (COMT) within platelets. CONCLUSIONS/SIGNIFICANCE: Platelets potentially mediate a third phase of flavonoid metabolism, which may impact on the regulation of the function of these cells by metabolites of these dietary compounds