Apricot carotenoids possess potent anti-amyloidogenic activity in vitro

Effects and Mechanisms of Lutein on Aging and Age-Related Diseases

Aging and age-related diseases are serious public health issues that are receiving growing attention from researchers. Lutein has a critical function in the prevention and management of these issues. Possible mechanisms mainly include suppressing inflammation and oxidative stress, regulating cell activity, and modulating the levels of toxic substances. In this narrative review paper, we sum up the most current developments in the study of the effects of lutein on aging and five age-related diseases (age-related macular degeneration, cataracts, Alzheimer's disease, Parkinson's disease, and osteoporosis), and fundamental mechanisms are reviewed. The bioavailability of lutein and the strategies to improve its bioavailability are discussed. This piece of work can bring a clearer comprehension of the protective effects of lutein against aging and age-related diseases and can be also helpful for developing lutein as functional food and dietary supplements for these age-related diseases.

Repurposing Anidulafungin for Alzheimer's Disease via Fragment-Based Drug Discovery

The misfolding and aggregation of beta-amyloid (Aβ) peptides have been implicated as key pathogenic events in the early stages of Alzheimer's disease (AD). Inhibiting Aβ aggregation represents a potential disease-modifying therapeutic approach to AD treatment. Previous studies have identified various molecules that inhibit Aβ aggregation, some of which share common chemical substructures (fragments) that may be key to their inhibitory activity. Employing fragment-based drug discovery (FBDD) methods may facilitate the identification of these fragments, which can subsequently be used to screen new inhibitors and provide leads for further drug development. In this study, we used an in silico FBDD approach to identify 17 fragment clusters that are significantly enriched among Aβ aggregation inhibitors. These fragments were then used to screen anti-infective agents, a promising drug class for repurposing against amyloid aggregation. This screening process identified 16 anti-infective drugs, 5 of which were chosen for further investigation. Among the 5 candidates, anidulafungin, an antifungal compound, showed high efficacy in inhibiting Aβ aggregation in vitro. Kinetic analysis revealed that anidulafungin selectively blocks the primary nucleation step of Aβ aggregation, substantially delaying Aβ fibril formation. Cell viability assays demonstrated that anidulafungin can reduce the toxicity of oligomeric Aβ on BV2 microglia cells. Molecular docking simulations predicted that anidulafungin interacted with various Aβ species, including monomers, oligomers, and fibrils, potentially explaining its activity against Aβ aggregation and toxicity. This study suggests that anidulafungin is a potential drug to be repurposed for AD, and FBDD is a promising approach for discovering drugs to combat Aβ aggregation.

Carotenoid Supplementation for Alleviating the Symptoms of Alzheimer's Disease

Alzheimer's disease (AD) is characterized by, among other things, dementia and a decline in cognitive performance. In AD, dementia has neurodegenerative features and starts with mild cognitive impairment (MCI). Research indicates that apoptosis and neuronal loss occur in AD, in which oxidative stress plays an important role. Therefore, reducing oxidative stress with antioxidants is a natural strategy to prevent and slow down the progression of AD. Carotenoids are natural pigments commonly found in fruits and vegetables. They include lipophilic carotenes, such as lycopene, α- and β-carotenes, and more polar xanthophylls, for example, lutein, zeaxanthin, canthaxanthin, and β-cryptoxanthin. Carotenoids can cross the blood-brain barrier (BBB) and scavenge free radicals, especially singlet oxygen, which helps prevent the peroxidation of lipids abundant in the brain. As a result, carotenoids have neuroprotective potential. Numerous in vivo and in vitro studies, as well as randomized controlled trials, have mostly confirmed that carotenoids can help prevent neurodegeneration and alleviate cognitive impairment in AD. While carotenoids have not been officially approved as an AD therapy, they are indicated in the diet recommended for AD, including the consumption of products rich in carotenoids. This review summarizes the latest research findings supporting the potential use of carotenoids in preventing and alleviating AD symptoms. A literature review suggests that a diet rich in carotenoids should be promoted to avoid cognitive decline in AD. One of the goals of the food industry should be to encourage the enrichment of food products with functional substances, such as carotenoids, which may reduce the risk of neurodegenerative diseases.

Lutein from Chicken Eggs Prevents Amyloid β-Peptide Aggregation In Vitro and Amyloid β-Induced Inflammation in Human Macrophages (THP-1)

Epidemiological studies predict that chicken eggs contain constituents other than proteins that prevent Alzheimer's disease. This study screened for constituents that inhibit the aggregation of amyloid β peptide (Aβ)1-42 and elucidated their mechanisms to explore the active components of chicken eggs. Thioflavin T assays and transmission electron microscopy observations showed that arachidonic acid (ARA), lysophosphatidylcholine, lutein (LTN), palmitoleic acid, and zeaxanthin inhibited Aβ aggregation. Among these, ARA and LTN showed the highest activity. Photoinduced cross-linking of unmodified protein assays and infrared absorption spectrometry measurements showed that LTN strongly inhibited highly toxic Aβ1-42 protofibril formation. Furthermore, LTN suppressed Aβ1-42-induced IL 1B and TNF expression in human macrophage-like cells. In summary, LTN plays a crucial role in the AD-preventive effect of chicken eggs by suppressing Aβ1-42 aggregation and Aβ1-42-induced inflammation.

Antioxidant and Neuroprotective Effects of Fucoxanthin and Its Metabolite Fucoxanthinol: A Comparative In Vitro Study

Fucoxanthin is the most abundant carotenoid found in marine brown algae that exhibits several healthy properties. Dietary fucoxanthin is metabolized in the intestine, plasma, and other tissues to various metabolites, including fucoxanthinol. In this regard, the contribution of fucoxanthinol to the healthy properties of its precursor, fucoxanthin, against pathogenetic events associated with neurodegenerative diseases remains unexplored. Here, we evaluated and compared the antioxidant and neuroprotective effects of the carotenoids fucoxanthin and fucoxanthinol in in vitro models of Alzheimer's (AD) and Parkinson's (PD) disease. Neuronal SH-SY5Y cells were used to evaluate the antioxidant properties of the carotenoids against ABTS radical in the membrane and cytoplasm and oxidative stress elicited by tert-butyl hydroperoxide using the 2',7'-dichlorodihydrofluorescein diacetate probe. We also assessed the ability of the carotenoids to increase the glutathione (GSH) and activate the Nrf2/Keap1/ARE pathway using the monochlorobimane probe and western blotting method, respectively. The neuroprotective effects of the carotenoids against the neurotoxicity generated by oligomers of Beta-Amyloid (1-42) peptide (OAβ) and 6-hydroxydopamine (6-OHDA), which are neurotoxins of AD and PD, respectively, were finally evaluated in the same neuronal cells using the thiazolyl blue tetrazolium bromide assay. Both carotenoids could reach the cytoplasm, which explains the mainly free radical scavenging activity at this level. Notably, fucoxanthinol had higher and lower antioxidant activity than fucoxanthin at extracellular and cellular levels. Although studied carotenoids exerted the ability to activate the Nrf2/Keap1/ARE pathway, leading to an increase of intracellular GSH, our results suggested that the antioxidant activity of the carotenoids could be mainly attributed to their radical scavenging activity in neuronal membrane and cytoplasm, where they accumulate. Fucoxanthinol also shared similar neuroprotective effects as fucoxanthin against the neurotoxicity generated by OAβ and 6-OHDA, suggesting a potential neuroprotective contribution to the action of fucoxanthin administered as a food supplement in in vivo experimental models. These results encourage further research to evaluate the bioavailability of fucoxanthinol and other metabolites of fucoxanthin at the brain level to elucidate the dietary neuroprotective potential of fucoxanthin.

Tetraselmis chuii Edible Microalga as a New Source of Neuroprotective Compounds Obtained Using Fast Biosolvent Extraction

Tetraselmis chuii is an EFSA-approved novel food and dietary supplement with increasing use in nutraceutical production worldwide. This study investigated the neuroprotective potential of bioactive compounds extracted from T. chuii using green biobased solvents (ethyl acetate, AcOEt, and cyclopentyl methyl ether, CPME) under pressurized liquid extraction (PLE) conditions and supercritical fluid extraction (SFE). Response surface optimization was used to study the effect of temperature and solvent composition on the neuroprotective properties of the PLE extracts, including anticholinergic activity, reactive oxygen/nitrogen species (ROS/RNS) scavenging capacity, and anti-inflammatory activity. Optimized extraction conditions of 40 °C and 34.9% AcOEt in CPME resulted in extracts with high anticholinergic and ROS/RNS scavenging capacity, while operation at 180 °C and 54.1% AcOEt in CPME yielded extracts with potent anti-inflammatory properties using only 20 min. Chemical characterization revealed the presence of carotenoids (neoxanthin, violaxanthin, zeaxanthin, α- and β-carotene) known for their anti-cholinesterase, antioxidant, and anti-inflammatory potential. The extracts also exhibited high levels of omega-3 polyunsaturated fatty acids (PUFAs) with a favorable ω-3/ω-6 ratio (>7), contributing to their neuroprotective and anti-inflammatory effects. Furthermore, the extracts were found to be safe to use, as cytotoxicity assays showed no observed toxicity in HK-2 and THP-1 cell lines at or below a concentration of 40 μg mL-1. These results highlight the neuroprotective potential of Tetraselmis chuii extracts, making them valuable in the field of nutraceutical production and emphasize the interest of studying new green solvents as alternatives to conventional toxic solvents.

Oxidative stress, the blood-brain barrier and neurodegenerative diseases: The critical beneficial role of dietary antioxidants

In recent years, growing awareness of the role of oxidative stress in brain health has prompted antioxidants, especially dietary antioxidants, to receive growing attention as possible treatments strategies for patients with neurodegenerative diseases (NDs). The most widely studied dietary antioxidants include active substances such as vitamins, carotenoids, flavonoids and polyphenols. Dietary antioxidants are found in usually consumed foods such as fresh fruits, vegetables, nuts and oils and are gaining popularity due to recently growing awareness of their potential for preventive and protective agents against NDs, as well as their abundant natural sources, generally non-toxic nature, and ease of long-term consumption. This review article examines the role of oxidative stress in the development of NDs, explores the 'two-sidedness' of the blood-brain barrier (BBB) as a protective barrier to the nervous system and an impeding barrier to the use of antioxidants as drug medicinal products and/or dietary antioxidants supplements for prevention and therapy and reviews the BBB permeability of common dietary antioxidant suplements and their potential efficacy in the prevention and treatment of NDs. Finally, current challenges and future directions for the prevention and treatment of NDs using dietary antioxidants are discussed, and useful information on the prevention and treatment of NDs is provided.

The association of MIND diet with cognitive resilience to neuropathologies

INTRODUCTION

Cognitive resilience (CR) can be defined as the continuum of better through worse than expected cognition, given the degree of neuropathology. The relation of healthy diet patterns to CR remains to be elucidated.

METHODS

Using longitudinal cognitive data and post mortem neuropathology from 578 deceased older adults, we examined associations between the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet at baseline and two standardized CR measures reflecting higher cognitive levels over time (CRLevel ¯ $_{\overline {{\rm{Level}}}} $ ), and slower decline (CRSlope ), than expected given neuropathology.

RESULTS

Compared to individuals in the lowest tertile of MIND score, those in the top tertile had higher CRLevel ¯ $_{\overline {{\rm{Level}}}} $ (mean difference [MD] = 0.34; 95% confidence interval [CI] = 0.14, 0.55) and CRSlope (MD = 0.27; 95% CI = 0.05, 0.48), after multivariable adjustment. Overall MIND score was more strongly related to CR than the individual food components.

DISCUSSION

The MIND diet is associated with both higher cognition and slower rates of cognitive decline, after controlling for neuropathology, indicating the MIND diet may be important to cognitive resilience.

MIND Dietary Pattern Adherence Is Selectively Associated with Cognitive Processing Speed in Middle-Aged Adults

BACKGROUND

Most previous work has focused on a single-nutrient, bottom-up approach when examining the influence of diet on neurocognition. Thus, the impact of dietary patterns on cognitive health is underinvestigated.

OBJECTIVES

We aimed to investigate the relation between different diet indices [i.e., Mediterranean, Dietary Approaches to Stop Hypertension (DASH), Healthy Eating Index-2015 (HEI-2015), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND)] and attentional inhibition and neuroelectric function.

METHODS

We undertook a cross-sectional analysis of adults aged 34.1 ± 6.0 y (n = 207, 116 females) with a BMI of 18.5 to >40 kg/m2 who completed the Dietary History Questionnaire II (DHQII) FFQ (Past Month and Year with Serving Sizes) to assess adherence to different diet quality indices. Attentional inhibition was assessed using a modified Eriksen flanker task during which event-related potentials (ERPs) were recorded. The amplitude and latency of the P3/P300 ERP were used to index attentional resource allocation and information processing speed, respectively.

RESULTS

P3 peak latency was inversely associated with greater adherence to the MIND dietary pattern during incongruent flanker trials (∆R2 = 0.02, β = -0.14, P = 0.043) but not during congruent trials. Adherence to the Mediterranean, DASH, and HEI-2015 patterns was not associated with P3 latency (P > 0.05). No associations were observed between the diet indices and attentional inhibition at the behavioral level (i.e., accuracy or reaction time) or P3 amplitude (all P values >0.05).

CONCLUSIONS

Greater adherence to the MIND diet was selectively associated with faster information processing speed in middle-aged adults with healthy to obese BMI. Further, the influence of the MIND diet for faster information processing speed might be particularly beneficial when cognitive control demands are increased. Future intervention trials testing the effects of consuming a MIND diet on cognitive function are warranted to help inform dietary recommendations for healthy cognitive aging.

Anticancer Potential and Other Pharmacological Properties of Prunus armeniaca L.: An Updated Overview

Prunus armeniaca L. (Rosaceae)-syn. Amygdalus armeniaca (L.) Dumort., Armeniaca armeniaca (L.) Huth, Armeniaca vulgaris Lam is commonly known as the apricot tree. The plant is thought to originate from the northern, north-western, and north-eastern provinces of China, although some data show that it may also come from Korea or Japan. The apricot fruit is used medicinally to treat a variety of ailments, including use as an antipyretic, antiseptic, anti-inflammatory, emetic, and ophthalmic remedy. The Chinese and Korean pharmacopeias describe the apricot seed as an herbal medicinal product. Various parts of the apricot plant are used worldwide for their anticancer properties, either as a primary remedy in traditional medicine or as a complementary or alternative medicine. The purpose of this review was to provide comprehensive and up-to-date information on ethnobotanical data, bioactive phytochemicals, anticancer potential, pharmacological applications, and toxicology of the genus Prunus armeniaca, thus providing new perspectives on future research directions. Included data were obtained from online databases such as PubMed/Medline, Google Scholar, Science direct, and Wiley Online Library. Multiple anticancer mechanisms have been identified in in vitro and in vivo studies, the most important mechanisms being apoptosis, antiproliferation, and cytotoxicity. The anticancer properties are probably mediated by the contained bioactive compounds, which can activate various anticancer mechanisms and signaling pathways such as tumor suppressor proteins that reduce the proliferation of tumor cells. Other pharmacological properties resulting from the analysis of experimental studies include neuroprotective, cardioprotective, antioxidant, immunostimulatory, antihyperlipidemic, antibacterial, and antifungal effects. In addition, data were provided on the toxicity of amygdalin, a compound found in apricot kernel seeds, which limits the long-term use of complementary/alternative products derived from P. armeniaca. This updated review showed that bioactive compounds derived from P. armeniaca are promising compounds for future research due to their important pharmacological properties, especially anticancer. A detailed analysis of the chemical structure of these compounds and their cytotoxicity should be carried out in future research. In addition, translational pharmacological studies are required for the correct determination of pharmacologically active doses in humans.

Carotenoids from Marine Sources as a New Approach in Neuroplasticity Enhancement

An increasing number of people experience disorders related to the central nervous system (CNS). Thus, new forms of therapy, which may be helpful in repairing processes' enhancement and restoring declined brain functions, are constantly being sought. One of the most relevant physiological processes occurring in the brain for its entire life is neuroplasticity. It has tremendous significance concerning CNS disorders since neurological recovery mainly depends on restoring its structural and functional organization. The main factors contributing to nerve tissue damage are oxidative stress and inflammation. Hence, marine carotenoids, abundantly occurring in the aquatic environment, being potent antioxidant compounds, may play a pivotal role in nerve cell protection. Furthermore, recent results revealed another valuable characteristic of these compounds in CNS therapy. By inhibiting oxidative stress and neuroinflammation, carotenoids promote synaptogenesis and neurogenesis, consequently presenting neuroprotective activity. Therefore, this paper focuses on the carotenoids obtained from marine sources and their impact on neuroplasticity enhancement.

Polyphenol-rich tart cherries (Prunus Cerasus, cv Montmorency) improve sustained attention, feelings of alertness and mental fatigue and influence the plasma metabolome in middle-aged adults: a randomised, placebo-controlled trial

Tart Montmorency cherries (MC) are a particularly rich source of anthocyanins and other polyphenols that have been shown to elicit antioxidant, anti-inflammatory and vasomodulatory actions. The current study aimed to determine the influence of chronic MC supplementation on cognitive function and mood. In a 3-month double-blinded, placebo-controlled parallel study, middle-aged adults (mean ± sd: 48 ± 6 years) were randomly assigned to either 30 ml twice daily of MC (n 25) or the same amount of an isoenergetic placebo (n 25). Cognitive function and mood were assessed before and after supplementation using a computerised cognitive task battery and visual analogue scales. Cerebral blood flow was also monitored by near-infrared spectroscopy during the task battery, and questionnaires were administered to determine subjective sleep and health status and plasma metabolomics were analysed before and after supplementation. After 3 months, the MC resulted in higher accuracy in digit vigilance (mean difference: 3·3, 95 % CI: 0·2, 6·4 %) with lower number of false alarms (mean difference: -1·2, 95 % CI: -2·0, -0·4) compared with the placebo. There was also a treatment effect for higher alertness (mean difference: 5·9, 95 % CI: 1·3, 10·5 %) and lower mental fatigue ratings (mean difference -9·5, 95 % CI: -16·5, -2·5 %) with MC. Plasma metabolomics revealed an increase in a number of amino acids in response to MC intake, but not placebo. These data suggest an anti-fatiguing effect of MC supplementation as well as the ability to improve sustained attention during times of high cognitive demand, this could be related to changes in amino acid metabolism.

Therapeutic promise of carotenoids as antioxidants and anti-inflammatory agents in neurodegenerative disorders

Neurodegenerative disorders (NDs) including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis have various disease-specific causal factors and pathological features. A very common characteristic of NDs is oxidative stress (OS), which takes place due to the elevated generation of reactive oxygen species during the progression of NDs. Furthermore, the pathological condition of NDs including an increased level of protein aggregates can further lead to chronic inflammation because of the microglial activation. Carotenoids (CTs) are naturally occurring pigments that play a significant role in averting brain disorders. More than 750 CTs are present in nature, and they are widely available in plants, microorganisms, and animals. CTs are accountable for the red, yellow, and orange pigments in several animals and plants, and these colors usually indicate various types of CTs. CTs exert various bioactive properties because of its characteristic structure, including anti-inflammatory and antioxidant properties. Due to the protective properties of CTs, levels of CTs in the human body have been markedly linked with the prevention and treatment of multiple diseases including NDs. In this review, we have summarized the relationship between OS, neuroinflammation, and NDs. In addition, we have also particularly focused on the antioxidants and anti-inflammatory properties of CTs in the management of NDs.

The neuroprotective potential of carotenoids in vitro and in vivo

BACKGROUND

Despite advances in research on neurodegenerative diseases, the pathogenesis and treatment response of neurodegenerative diseases remain unclear. Recent studies revealed a significant role of carotenoids to treat neurodegenerative diseases. The aim of this study was to systematically review the neuroprotective potential of carotenoids in vivo and in vitro and the molecular mechanisms and pathological factors contributing to major neurodegenerative diseases (Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, and stroke).

HYPOTHESIS

Carotenoids as therapeutic molecules to target neurodegenerative diseases.

RESULTS

Aggregation of toxic proteins, mitochondrial dysfunction, oxidative stress, the excitotoxic pathway, and neuroinflammation were the major pathological factors contributing to the progression of neurodegenerative diseases. Furthermore, in vitro and in vivo studies supported the beneficiary role of carotenoids, namely lycopene, β-carotene, crocin, crocetin, lutein, fucoxanthin and astaxanthin in alleviating disease progression. These carotenoids provide neuroprotection by inhibition of neuro-inflammation, microglial activation, excitotoxic pathway, modulation of autophagy, attenuation of oxidative damage and activation of defensive antioxidant enzymes. Additionally, studies conducted on humans also demonstrated that dietary intake of carotenoids lowers the risk of neurodegenerative diseases.

CONCLUSION

Carotenoids may be used as drugs to prevent and treat neurodegenerative diseases. Although, the in vitro and in vivo results are encouraging, further well conducted clinical studies on humans are required to conclude about the full potential of neurodegenerative diseases.

Multimodal, label-free fluorescence and Raman imaging of amyloid deposits in snap-frozen Alzheimer's disease human brain tissue

Alzheimer's disease (AD) neuropathology is characterized by hyperphosphorylated tau containing neurofibrillary tangles and amyloid-beta (Aβ) plaques. Normally these hallmarks are studied by (immuno-) histological techniques requiring chemical pretreatment and indirect labelling. Label-free imaging enables one to visualize normal tissue and pathology in its native form. Therefore, these techniques could contribute to a better understanding of the disease. Here, we present a comprehensive study of high-resolution fluorescence imaging (before and after staining) and spectroscopic modalities (Raman mapping under pre-resonance conditions and stimulated Raman scattering (SRS)) of amyloid deposits in snap-frozen AD human brain tissue. We performed fluorescence and spectroscopic imaging and subsequent thioflavin-S staining of the same tissue slices to provide direct confirmation of plaque location and correlation of spectroscopic biomarkers with plaque morphology; differences were observed between cored and fibrillar plaques. The SRS results showed a protein peak shift towards the β-sheet structure in cored amyloid deposits. In the Raman maps recorded with 532 nm excitation we identified the presence of carotenoids as a unique marker to differentiate between a cored amyloid plaque area versus a non-plaque area without prior knowledge of their location. The observed presence of carotenoids suggests a distinct neuroinflammatory response to misfolded protein accumulations.

Pouteria sapota (Red Mamey Fruit): Chemistry and Biological Activity of Carotenoids

BACKGROUND

Red mamey fruit known as P. sapota, comes from trees found in Mesoamerica and Asia. This fruit is considered a nutraceutical food due to it's a food and has multiple beneficial health including anti-amyloidogenic activity and potential anti-tumorigenic property. Red mamey fruit contain a variety of carotenoids including novel ketocarotenoids such as sapotexanthin and cryptocapsin. A ketocarotenoid is a chemical compound with a carbonyl group present in the β-ring or in the double bond chain of a carotenoid. In red mamey, the 3'-deoxy-k-end group in sapotexanthin has proved to be an important pro-vitamin A source, which is essential for maintaining a healthy vision and cognitive processes.

OBJECTIVE

Summarize the chemistry and biological activity of the studied carotenoids present in this fruit until now.

METHOD

An exhaustive extraction is the most usual methodology to isolate and thoroughly characterize the carotenoids present in this fruit. High performance liquid chromatography is used to determine the profile of total carotenoid and its purity. Atmospheric pressure chemical ionization is used to determine the molecular weight of carotenoid. Nuclear magnetic resonance is used to determine the structure of carotenoids.

RESULT

For each 100 g of fresh weight, 0.12 mg of total carotenoid from this fruit can be obtained. Out of the more than 47 reported carotenoids in red mamey, only 34 have a detailed characterization.

CONCLUSION

it is important to continue studying the chemical composition and biological activity of this unique tropical fruit with commercial and nutritional value.

Molecular Bases of Fruit Quality in Prunus Species: An Integrated Genomic, Transcriptomic, and Metabolic Review with a Breeding Perspective

In plants, fruit ripening is a coordinated developmental process that requires the change in expression of hundreds to thousands of genes to modify many biochemical and physiological signal cascades such as carbohydrate and organic acid metabolism, cell wall restructuring, ethylene production, stress response, and organoleptic compound formation. In Prunus species (including peaches, apricots, plums, and cherries), fruit ripening leads to the breakdown of complex carbohydrates into sugars, fruit firmness reductions (softening by cell wall degradation and cuticle properties alteration), color changes (loss of green color by chlorophylls degradation and increase in non-photosynthetic pigments like anthocyanins and carotenoids), acidity decreases, and aroma increases (the production and release of organic volatile compounds). Actually, the level of information of molecular events at the transcriptional, biochemical, hormonal, and metabolite levels underlying ripening in Prunus fruits has increased considerably. However, we still poorly understand the molecular switch that occurs during the transition from unripe to ripe fruits. The objective of this review was to analyze of the molecular bases of fruit quality in Prunus species through an integrated metabolic, genomic, transcriptomic, and epigenetic approach to better understand the molecular switch involved in the ripening process with important consequences from a breeding point of view.

Stone Fruit as Biofactories of Phytochemicals With Potential Roles in Human Nutrition and Health

Phytochemicals or secondary metabolites present in fruit are key components contributing to sensory attributes like aroma, taste, and color. In addition, these compounds improve human nutrition and health. Stone fruits are an important source of an array of secondary metabolites that may reduce the risk of different diseases. The first part of this review is dedicated to the description of the main secondary organic compounds found in plants which include (a) phenolic compounds, (b) terpenoids/isoprenoids, and (c) nitrogen or sulfur containing compounds, and their principal biosynthetic pathways and their regulation in stone fruit. Then, the type and levels of bioactive compounds in different stone fruits of the Rosaceae family such as peach (Prunus persica), plum (P. domestica, P. salicina and P. cerasifera), sweet cherries (P. avium), almond kernels (P. dulcis, syn. P. amygdalus), and apricot (P. armeniaca) are presented. The last part of this review encompasses pre- and postharvest treatments affecting the phytochemical composition in stone fruit. Appropriate management of these factors during pre- and postharvest handling, along with further characterization of phytochemicals and the regulation of their synthesis in different cultivars, could help to increase the levels of these compounds, leading to the future improvement of stone fruit not only to enhance organoleptic characteristics but also to benefit human health.

Long-Term Intake of Dietary Carotenoids Is Positively Associated with Late-Life Subjective Cognitive Function in a Prospective Study in US Women

BACKGROUND

A protective association of dietary carotenoids with cognitive function has been suggested, but most studies have been relatively small with limited periods of follow-up.

OBJECTIVES

We examined prospectively long-term intakes of carotenoids in relation to subjective cognitive function (SCF), a self-reported, validated indicator of cognitive dysfunction.

METHODS

Among 49,493 female registered nurses with a mean age of 48 y in 1984, we used multinomial logistic regression to estimate the ORs and 95% CIs relating intakes of carotenoids to self-reported SCF in 2012 and 2014. Mean intakes of carotenoids were calculated from 7 repeated FFQs collected in 1984, 1986, and every 4 y afterwards until 2006. Self-reported SCF was assessed by a 7-item questionnaire on changes in memory and cognition; validity was supported by strong associations with Apolipoprotein E (APOE) ε4 genotype and concurrent cognitive function and cognitive decline measured by telephone-based neuropsychological tests. The mean values of scores assessed in 2012 and 2014 were categorized as "good" (0 points, 40.8%), "moderate" (0.5-2.5 points, 46.9%), and "poor" (3-7 points, 12.3%).

RESULTS

Higher intake of total carotenoids was associated with substantially lower odds of moderate or poor cognitive function after controlling for other dietary and nondietary risk factors and total energy intake. Comparing the top with the bottom quintile of total carotenoids, the multivariable ORs were 0.86 (95% CI: 0.80, 0.93; P-trend < 0.001) for moderate SCF and 0.67 (95% CI: 0.60, 0.75; P-trend < 0.001) for poor SCF. This lower OR was also seen for carotenoids consumed 28 y before SCF assessment. Similar associations were found for total β-carotene, dietary β-carotene, α-carotene, lycopene, lutein + zeaxanthin, and β-cryptoxanthin. The significant associations for β-cryptoxanthin, lycopene, and lutein + zeaxanthin persisted after mutual adjustment for each other.

CONCLUSIONS

Our findings support a long-term beneficial role of carotenoid consumption on cognitive function in women.

Cyanidin-3-O-glucoside inhibits Aβ40 fibrillogenesis, disintegrates preformed fibrils, and reduces amyloid cytotoxicity

Alzheimer's disease (AD) is mainly caused by the fibrillogenesis of amyloid-β protein (Aβ). Therefore, the development of effective inhibitors against Aβ fibrillogenesis offers great hope for the treatment of AD. Cyanidin-3-O-glucoside (Cy-3G) is a commonly found anthocyanin that is mainly present in fruits, with established neuroprotective effects in situ. However, it remains unknown if Cy-3G can prevent Aβ fibrillogenesis and alleviate the corresponding cytotoxicity. In this study, extensive biochemical, biophysical, biological and computational experiments were combined to address this issue. It was found that Cy-3G significantly inhibits Aβ40 fibrillogenesis and disintegrates mature Aβ fibrils, and its inhibitory capacity is dependent on the Cy-3G concentration. The circular dichroism results showed that Cy-3G and Aβ40 at a molar ratio of 3 : 1 slightly prevents the structural transformation of Aβ40 from its initial random coil to the β-sheet-rich structure. Co-incubation of Aβ40 with Cy-3G significantly reduced the production of intracellular reactive oxygen species induced by Aβ40 fibrillogenesis and thus reduced Aβ40-induced cytotoxicity. Molecular dynamics simulations revealed that Cy-3G disrupted the β-sheet structure of the Aβ40 trimer. Cy-3G was found to mainly interact with the N-terminal region, the central hydrophobic cluster and the β-sheet region II via hydrophobic and electrostatic interactions. The ten hot spot residues D7, Y10, E11, F19, F20, E22, I31, I32, M35 and V40 were also identified. These findings not only enable a comprehensive understanding of the inhibitory effect of Cy-3G on Aβ40 fibrillogenesis, but also allow the identification of a valuable dietary ingredient that possesses great potential to be developed into functional foods to alleviate AD.

Carotenoids as Novel Therapeutic Molecules Against Neurodegenerative Disorders: Chemistry and Molecular Docking Analysis

Alzheimer's disease (AD) is the most devastating neurodegenerative disorder that affects the aging population worldwide. Endogenous and exogenous factors are involved in triggering this complex and multifactorial disease, whose hallmark is Amyloid-β (Aβ), formed by cleavage of amyloid precursor protein by β- and γ-secretase. While there is no definitive cure for AD to date, many neuroprotective natural products, such as polyphenol and carotenoid compounds, have shown promising preventive activity, as well as helping in slowing down disease progression. In this article, we focus on the chemistry as well as structure of carotenoid compounds and their neuroprotective activity against Aβ aggregation using molecular docking analysis. In addition to examining the most prevalent anti-amyloidogenic carotenoid lutein, we studied cryptocapsin, astaxanthin, fucoxanthin, and the apocarotenoid bixin. Our computational structure-based drug design analysis and molecular docking simulation revealed important interactions between carotenoids and Aβ via hydrogen bonding and van der Waals interactions, and shows that carotenoids are powerful anti-amyloidogenic molecules with a potential role in preventing AD, especially since most of them can cross the blood-brain barrier and are considered nutraceutical compounds. Our studies thus illuminate mechanistic insights on how carotenoids inhibit Aβ aggregation. The potential role of carotenoids as novel therapeutic molecules in treating AD and other neurodegenerative disorders are discussed.

A combinational treatment of carotenoids decreases Aβ secretion in human neurons via β-secretase inhibition

Alzheimer's disease (AD) is the most common cause of dementia and is characterized neuropathologically by the presence of amyloid plaques and neurofibrillary tangles. Amyloid-β (Aβ) peptides, major components of amyloid plaques and crucial pathogenic molecules in terms of the amyloid hypothesis, are derived from successive proteolytic processing of amyloid-β precursor protein (APP). In this study, we established a human neuronal culture system using induced pluripotent stem cells (iPSCs) to evaluate the possible effects of natural compounds on the amyloid phenotype. Unexpectedly, we found that combinational treatment of carotenoids, but not docosahexaenoic acid, significantly decreased Aβ secretion from iPSC-derived human cortical neurons. Importantly, the effects of the carotenoids resulted from specific inhibition of BACE1 activity and not from expression changes in APP or BACE1. Therefore, these results indicate a novel beneficial function of carotenoids in the anti-amyloidogenic processing of APP. Collectively, this study will shed light on neuronal protection by a novel mechanism during the pathogenesis of AD.

Pathological and cognitive changes in patients with type 2 diabetes mellitus and comorbid MCI and protective hypoglycemic therapies: a narrative review

Type 2 diabetes mellitus (T2DM) is becoming a significant health issue worldwide. Many studies support the hypothesis that patients with T2DM have a higher-than-expected incidence of mild cognitive impairment (MCI) than individuals without diabetes. Based on the results from recent studies, MCI might be associated with the effects of T2DM on glucose metabolism and brain atrophy. As a narrative review, we will illuminate pathological and cognitive changes in patients with T2DM and comorbid MCI and protective hypoglycemic therapies. The early abnormal signs of cognition must be elucidated, and extensive investigations are needed to develop improved therapies for use in the clinic.

Adzuki bean (Vigna angularis) extract reduces amyloid-β aggregation and delays cognitive impairment in Drosophila models of Alzheimer's disease

BACKGROUND/OBJECTIVES

Alzheimer's disease is a neurodegenerative disease that induces symptoms such as a decrease in motor function and cognitive impairment. Increases in the aggregation and deposition of amyloid beta protein (Aβ) in the brain may be closely correlated with the development of Alzheimer's disease. In this study, the effects of an adzuki bean extract on the aggregation of Aβ were examined; moreover, the anti-Alzheimer's activity of the adzuki extract was examined.

MATERIALS/METHODS

First, we undertook thioflavin T (ThT) fluorescence analysis and transmission electron microscopy (TEM) to evaluate the effect of an adzuki bean extract on Aβ₄₂ aggregation. To evaluate the effects of the adzuki extract on the symptoms of Alzheimer's disease in vivo, Aβ₄₂-overexpressing Drosophila were used. In these flies, overexpression of Aβ₄₂ induced the formation of Aβ₄₂ aggregates in the brain, decreased motor function, and resulted in cognitive impairment.

RESULTS

Based on the results obtained by ThT fluorescence assays and TEM, the adzuki bean extract inhibited the formation of Aβ₄₂ aggregates in a concentration-dependent manner. When Aβ₄₂-overexpressing flies were fed regular medium containing adzuki extract, the Aβ₄₂ level in the brain was significantly lower than that in the group fed regular medium only. Furthermore, suppression of the decrease in motor function, suppression of cognitive impairment, and improvement in lifespan were observed in Aβ₄₂-overexpressing flies fed regular medium with adzuki extract.

CONCLUSIONS

The results reveal the delaying effects of an adzuki bean extract on the progression of Alzheimer's disease and provide useful information for identifying novel prevention treatments for Alzheimer's disease.

Effect of catechins and high-temperature-processed green tea extract on scavenging reactive oxygen species and preventing Aβ1-42 fibrils' formation in brain microvascular endothelium

The present study investigated the effect of high-temperature-processed green tea extract (HTP_GTE) and its bioactive components on the reduction of reactive oxygen species (ROS) and amyloid-beta (Aβ) protein in human microvascular endothelial cells. Compared to Aβ_1-42-only treatment, pretreatment of HTP_GTE was revealed to effectively inhibit ROS generation (P<0.05). HTP_GTE and catechins not only inhibit Aβ_1-42 fibril formation but also destabilize preformed Aβ_1-42 fibrils. The presence of HTP_GTE, Aβ_1-42 fibril formation was significantly inhibited in a dose-dependent manner at 12.5-100 μg/ml of HTP_GTE, showing 86-56%, respectively. Treatment of various concentrations of HTP_GTE and catechins steadily destabilized the preformed Aβ_1-42 fibrils for 24 h in a dose-dependent manner. It was observed that the gallated groups such as epigallocatechin gallate, epicatechin gallate, gallocatechin gallate, and catechin gallate more effectively disturbed Aβ_1-42 fibril formation and destabilized the preformed Aβ_1-42 fibrils than the non-gallated group. Taken together, these findings supported that sterilized green tea could be promising natural anti-amyloidogenic agents associated with therapeutic approaches in Alzheimer's disease by scavenging ROS generation and Aβ fibril in the brain tissue.

Recent Advances in Studies on the Therapeutic Potential of Dietary Carotenoids in Neurodegenerative Diseases

Carotenoids, symmetrical tetraterpenes with a linear C40 hydrocarbon backbone, are natural pigment molecules produced by plants, algae, and fungi. Carotenoids have important functions in the organisms (including animals) that obtain them from food. Due to their characteristic structure, carotenoids have bioactive properties, such as antioxidant, anti-inflammatory, and autophagy-modulatory activities. Given the protective function of carotenoids, their levels in the human body have been significantly associated with the treatment and prevention of various diseases, including neurodegenerative diseases. In this paper, we review the latest studies on the effects of carotenoids on neurodegenerative diseases in humans. Furthermore, animal and cellular model studies on the beneficial effects of carotenoids on neurodegeneration are also reviewed. Finally, we discuss the possible mechanisms and limitations of carotenoids in the treatment and prevention of neurological diseases.

Association of Long-Term Adherence to the MIND Diet with Cognitive Function and Cognitive Decline in American Women

OBJECTIVES

There is increasing attention for dietary patterns as a potential strategy to prevent cognitive decline. We examined the association between adherence to a recently developed Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet with cognitive function and cognitive decline, taking into account the interaction between the apolipoprotein E ε4 genotype and the MIND diet.

DESIGN

Population-based prospective cohort study.

PARTICIPANTS

A total of 16,058 older women aged 70 and over from the Nurses' Health Study.

MEASUREMENTS

Dietary intake was assessed five times between 1984 and 1998 with a 116-item Food Frequency Questionnaire. The MIND score includes ten brain-healthy foods and five unhealthy foods. Cognition was assessed four times by telephone from 1995 to 2001 (baseline) with the Telephone Interview for Cognitive Status (TICS) and by calculating composite scores of verbal memory and global cognition. Linear regression modelling and linear mixed modelling were used to examine the associations of adherence to the MIND diet with average cognitive function and cognitive change over six years, respectively.

RESULTS

Greater long-term adherence to the MIND diet was associated with a better verbal memory score (multivariable-adjusted mean differences between extreme MIND quintiles=0.04 (95%CI 0.01-0.07), p-trend=0.006), but not with cognitive decline over 6 years in global cognition, verbal memory or TICS.

CONCLUSION

Long-term adherence to the MIND diet was moderately associated with better verbal memory in later life. Future studies should address this association within populations at greater risk of cognitive decline.

TMPyP Inhibits Amyloid-β Aggregation and Alleviates Amyloid-Induced Cytotoxicity

The aggregation or misfolding of amyloid-β (Aβ) is a major pathological hallmark of Alzheimer's disease (AD). The regulation of Aβ aggregation is thought to be an effective strategy for AD treatment. The capability of a water-soluble porphyrin, 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP), to inhibit Aβ aggregation and to lower Aβ-induced toxicity was demonstrated. As evidenced by surface plasmon resonance and circular dichroism, TMPyP can not only disrupt Aβ aggregation but also disassemble the preformed Aβ aggregates. The atomic force microscopy imaging proves that TMPyP inhibits the formation of both oligomers and fibrils. Molecular dynamic simulations provide an insight into the interaction between TMPyP and Aβ at the molecular level. The half-maximal inhibitory concentrations of TMPyP acting on the oligomers and fibrils were determined to be 0.6 and 0.43 μM, respectively. As a member of porphyrin family, TMPyP is of rather low cytotoxicity, and the cytotoxicity of the Aβ aggregates was also relieved upon coincubation with TMPyP. The excellent performance of TMPyP thus makes it a potential drug candidate for AD therapy.

Fucoxanthin Inhibits β-Amyloid Assembly and Attenuates β-Amyloid Oligomer-Induced Cognitive Impairments

β-Amyloid (Aβ) can form aggregates through self-assembly and produce neurotoxicity in the early stage of Alzheimer's disease (AD). Therefore, the inhibition of Aβ assembly is considered as the primary target for AD therapy. In this study, we reported that fucoxanthin, a marine carotenoid, potently reduced the formation of Aβ fibrils and oligomers. Moreover, the fucoxanthin-triggered modification significantly reduced the neurotoxicity of Aβ oligomers in vitro. Molecular dynamics simulation analysis further revealed a hydrophobic interaction between fucoxanthin and Aβ peptide, which might prevent the conformational transition and self-assembly of Aβ. Most importantly, fucoxanthin could attenuate cognitive impairments in Aβ oligomer-injected mice. In addition, fucoxanthin significantly inhibited oxidative stress, enhanced the expression of brain-derived neurotrophic factor, and increased ChAT-positive regions in the hippocampus of mice. On the basis of these novel findings, we anticipated that fucoxanthin might ameliorate AD via inhibiting Aβ assembly and attenuating Aβ neurotoxicity.

Molecular Anti-inflammatory Mechanisms of Retinoids and Carotenoids in Alzheimer's Disease: a Review of Current Evidence

Alzheimer's disease (AD) is considered as one of the most prevalent neurodegenerative disorders characterized by progressive loss of mental function and ability to learn. AD is a multifactorial disorder. Various hypotheses are suggested for the pathophysiology of AD including "Aβ hypothesis," "tau hypothesis," and "cholinergic hypothesis." Recently, it has been demonstrated that neuroinflammation is involved in the pathogenesis of AD. Neuroinflammation causes synaptic dysfunction and neuronal death within the brain. Excessive production of pro-inflammatory mediators induces Aβ peptide production/accumulation and hyperphosphorylated tau generating inflammatory molecules and cytokines. These inflammatory molecules disrupt blood-brain barrier integrity and increase the production of Aβ42 oligomers. Retinoids and carotenoids are potent antioxidants and anti-inflammatory agents having neuroprotective properties. They are able to prevent disease progression through several mechanisms such as suppression of Aβ peptide production/accumulation, oxidative stress, and pro-inflammatory mediator's secretion as well as improvement of cognitive performance. These observations, therefore, confirm the neuroprotective role of retinoids and carotenoids through multiple pathways. Therefore, the administration of these nutrients is considered as a promising approach to the prevention and/or treatment of AD in the future. The aim of this review is to present existing evidences regarding the beneficial effects of retinoids and carotenoids on AD's risk and outcomes, seeking the mechanism of their action.

Hematoxylin Inhibits Amyloid β-Protein Fibrillation and Alleviates Amyloid-Induced Cytotoxicity

Accumulation and aggregation of amyloid β-protein (Aβ) play an important role in the pathogenesis of Alzheimer's disease. There has been increased interest in finding new anti-amyloidogenic compounds to inhibit Aβ aggregation. Herein, thioflavin T fluorescent assay and transmission electron microscopy results showed that hematoxylin, a natural organic molecule extracted from Caesalpinia sappan, was a powerful inhibitor of Aβ42 fibrillogenesis. Circular dichroism studies revealed hematoxylin reduced the β-sheet content of Aβ42 and made it assemble into antiparallel arrangement, which induced Aβ42 to form off-pathway aggregates. As a result, hematoxylin greatly alleviated Aβ42-induced cytotoxicity. Molecular dynamics simulations revealed the detailed interactions between hematoxylin and Aβ42. Four binding sites of hematoxylin on Aβ42 hexamer were identified, including the N-terminal region, S8GY10 region, turn region, and C-terminal region. Notably, abundant hydroxyl groups made hematoxylin prefer to interact with Aβ42 via hydrogen bonds. This also contributed to the formation of π-π stacking and hydrophobic interactions. Taken together, the research proved that hematoxylin was a potential agent against Aβ fibrillogenesis and cytotoxicity.

Cognitive Function and Its Relationship with Macular Pigment Optical Density and Serum Concentrations of its Constituent Carotenoids

Background: Macular pigment (MP) levels correlate with brain concentrations of lutein (L) and zeaxanthin (Z), and have also been shown to correlate with cognitive performance in the young and elderly.

Objective: To investigate the relationship between MP, serum concentrations of L and Z, and cognitive function in subjects free of retinal disease with low MP (Group 1, n = 105) and in subjects with AMD (Group 2, n = 121).

Methods: MP was measured using customized heterochromatic flicker photometry and dual-wavelength autofluorescence; cognitive function was assessed using a battery of validated cognition tests; serum L and Z concentrations were determined by HPLC.

Results: Significant correlations were evident between MP and various measures of cognitive function in both groups (r = –0.273 to 0.261, p≤0.05, for all). Both serum L and Z concentrations correlated significantly (r = 0.187, p≤0.05 and r = 0.197, p≤0.05, respectively) with semantic (animal) fluency cognitive scores in Group 2 (the AMD study group), while serum L concentrations also correlated significantly with Verbal Recognition Memory learning slope scores in the AMD study group (r = 0.200, p = 0.031). Most of the correlations with MP, but not serum L or Z, remained significant after controlling for age, gender, diet, and education level.

Conclusion: MP offers potential as a non-invasive clinical biomarker of cognitive health, and appears more successful in this role than serum concentrations of L or Z.

MIND diet slows cognitive decline with aging

INTRODUCTION

The Mediterranean and dash diets have been shown to slow cognitive decline; however, neither diet is specific to the nutrition literature on dementia prevention.

METHODS

We devised the Mediterranean-Dietary Approach to Systolic Hypertension (DASH) diet intervention for neurodegenerative delay (MIND) diet score that specifically captures dietary components shown to be neuroprotective and related it to change in cognition over an average 4.7 years among 960 participants of the Memory and Aging Project.

RESULTS

In adjusted mixed models, the MIND score was positively associated with slower decline in global cognitive score (β = 0.0092; P < .0001) and with each of five cognitive domains. The difference in decline rates for being in the top tertile of MIND diet scores versus the lowest was equivalent to being 7.5 years younger in age.

DISCUSSION

The study findings suggest that the MIND diet substantially slows cognitive decline with age. Replication of these findings in a dietary intervention trial would be required to verify its relevance to brain health.

Polyphenols as therapeutic molecules in Alzheimer's disease through modulating amyloid pathways

Alzheimer's disease (AD) is a complex and multifactorial neurodegenerative condition. The complex pathology of this disease includes oxidative stress, metal deposition, formation of aggregates of amyloid and tau, enhanced immune responses, and disturbances in cholinesterase. Drugs targeted toward reduction of amyloidal load have been discovered, but there is no effective pharmacological treatment for combating the disease so far. Natural products have become an important avenue for drug discovery research. Polyphenols are natural products that have been shown to be effective in the modulation of the type of neurodegenerative changes seen in AD, suggesting a possible therapeutic role. The present review focuses on the chemistry of polyphenols and their role in modulating amyloid precursor protein (APP) processing. We also provide new hypotheses on how these therapeutic molecules may modulate APP processing, prevent Aβ aggregation, and favor disruption of preformed fibrils. Finally, the role of polyphenols in modulating Alzheimer's pathology is discussed.

Lutein: more than just a filter for blue light

Lutein is concentrated in the primate retina, where together with zeaxanthin it forms the macular pigment. Traditionally lutein is characterized by its blue light filtering and anti-oxidant properties. Eliminating lutein from the diet of experimental animals results in early degenerative signs in the retina while patients with an acquired condition of macular pigment loss (Macular Telangiectasia) show serious visual handicap indicating the importance of macular pigment. Whether lutein intake reduces the risk of age related macular degeneration (AMD) or cataract formation is currently a strong matter of debate and abundant research is carried out to unravel the biological properties of the lutein molecule. SR-B1 has recently been identified as a lutein binding protein in the retina and this same receptor plays a role in the selective uptake in the gut. In the blood lutein is transported via high-density lipoproteins (HDL). Genes controlling SR-B1 and HDL levels predispose to AMD which supports the involvement of cholesterol/lutein transport pathways. Apart from beneficial effects of lutein intake on various visual function tests, recent findings show that lutein can affect immune responses and inflammation. Lutein diminishes the expression of various ocular inflammation models including endotoxin induced uveitis, laser induced choroidal neovascularization, streptozotocin induced diabetes and experimental retinal ischemia and reperfusion. In vitro studies show that lutein suppresses NF kappa-B activation as well as the expression of iNOS and COX-2. Since AMD has features of a chronic low-grade systemic inflammatory response, attention to the exact role of lutein in this disease has shifted from a local effect in the eye towards a possible systemic anti-inflammatory function.