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

Associations of multiple carotenoid co-exposure with all-cause and cause-specific mortality in US adults: a prospective cohort study

Background

Epidemiological evidence regarding circulating carotenoids and mortality risk remains conflicting, and most studies focus on the impact of individual carotenoids. This study aimed to elucidate the effects of co-exposure to multiple serum carotenoids on mortality risk.

Methods

We enrolled 22,472 participants aged ≥20 from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 2003-2006. Baseline serum levels of five major carotenoids (α-carotene, β-carotene, lycopene, β-cryptoxanthin, and lutein/zeaxanthin) were measured, and individuals were followed up until December 31, 2019. Carotenoid co-exposure patterns were identified using the K-means method. Cox proportional hazard models were used to investigate the associations between carotenoid exposure and mortality risk.

Results

During a median follow-up of 16.7 years, 7,901 deaths occurred. K-means clustered participants into low-level, low-lycopene, high-lycopene, and high-level exposure groups. In the fully adjusted model, low-lycopene, high-lycopene, and high-level exposure groups had significantly lower all-cause mortality risks compared to the low-level exposure group, with hazard ratios (HRs) and 95% confidence intervals (CIs) of 0.79 (0.72, 0.87), 0.75 (0.67, 0.84), and 0.67 (0.61, 0.74), respectively. For cardiovascular disease mortality, the high-lycopene exposure group had a 27% reduced risk (HR: 0.73, 95% CI: 0.61-0.86), and the high-level exposure group had a 21% reduced risk (HR: 0.79, 95% CI: 0.67-0.93). For cancer mortality, the high-lycopene and high-level exposure groups had 30% and 35% lower risks, with HRs (95% CIs) of 0.70 (0.57, 0.86) and 0.65 (0.54, 0.79), respectively.

Conclusion

This study revealed that co-exposure to multiple serum carotenoids was associated with reduced mortality risk, highlighting the potential health benefits of increased carotenoid intake. Further investigation is warranted to elucidate the underlying mechanisms of interactions among different carotenoids.

The bioactivities and biotechnological production approaches of carotenoids derived from microalgae and cyanobacteria

Microalgae and cyanobacteria are a rich source of carotenoids that are well known for their potent bioactivities, including antioxidant, anti-cancer, anti-proliferative, anti-inflammatory, and anti-obesity properties. Recently, many interests have also been focused on the biological activities of these microalgae/cyanobacteria-derived carotenoids, such as fucoxanthin and β-carotene potential to be the salutary nutraceuticals, on treating or preventing human common diseases (e.g., cancers). This is due to their special chemical structures that demonstrate unique bioactive functions, in which the biologically active discrepancies might attribute to the different spatial configurations of their molecules. In addition, their abundance and bioaccessibilities make them more popularly applied in food and pharmaceutical industries, as compared to the macroalgal/fungal-derived ones. This review is focused on the recent studies on the bioactivities of fucoxanthin and some carotenoids derived from microalgae and cyanobacteria in relationship with human health and diseases, with emphasis on their potential applications as natural antioxidants. Various biotechnological approaches employed to induce the production of these specific carotenoids from the culture of microalgae/cyanobacteria are also critically reviewed. These well-developed and emerging biotechnologies present promise to be applied in food and pharmaceutical industries to facilitate the efficient manufacture of the bioactive carotenoid products derived from microalgae and cyanobacteria.

Lutein and the Underlying Neuroprotective Promise against Neurodegenerative Diseases

Alzheimer's disease (AD) and Parkinson's diseases (PD) are the two most common progressive neurodegenerative diseases with limited knowledge on their cause and, presently, have no cure. There is an existence of multiple treatment methods that target only the symptoms temporarily and do not stop the progression or prevent the onset of disease. Neurodegeneration is primarily attributed to the natural process of aging and the deleterious effects of heightened oxidative stress within the brain, whether via direct or indirect mechanisms. Emerging evidence suggests that certain nutritional aspects play a crucial role in the prevention and management of neurodegenerative diseases. Lutein, a dietary carotenoid, has been studied for its antioxidant properties for more than a decade with several applications against age-related macular degeneration. It is high antioxidant potential and selective accumulation in the brain makes it a versatile compound for combatting various neurodegenerative diseases. In this review, the studies exhibiting neuroprotective properties of lutein against neurodegenerative conditions, more specifically AD and PD in various model systems as well as clinical observations have been reviewed. Accordingly, the concerns associated with lutein absorption and potential strategies to improve its bioavailability have been discussed.

Lycopene: A Potent Antioxidant with Multiple Health Benefits

Lycopene is a naturally occurring carotenoid predominantly found in tomatoes and tomato-based products. Like other phytochemicals, it exhibits health beneficial biological activities that can be exploited when it is used as a dietary supplement. In vitro and in vivo, lycopene has been demonstrated to mitigate oxidative stress-induced metabolic dysfunctions and diseases including inflammation, obesity, and diabetes mellitus. Lycopene has been shown to alleviate metabolic diseases that affect the bone, eye, kidney, liver, lungs, heart, and nervous system. This review presents the state of the art regarding lycopene's health benefits and its potential applications in health system delivery. Furthermore, lycopene's protective effects against toxins, safety in its use, and possible toxicity are explored.

Role of Algal-derived Bioactive Compounds in Human Health

Algae is emerging as a bioresource with high biological potential. Various algal strains have been used in traditional medicines and human diets worldwide. They are a rich source of bioactive compounds like ascorbic acid, riboflavin, pantothenate, biotin, folic acid, nicotinic acid, phycocyanins, gamma-linolenic acid (GLA), adrenic acid (ARA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), etc. Beta-carotene, astaxanthin, and phycobiliproteins are different classes of pigments that are found in algae. They possess antioxidant, anti-inflammatory and anticancer properties. The sulfur-coated polysaccharides in algae have been used as an anticancer, antibacterial, and antiviral agent. Scientists have exploited algal-derived bioactive compounds for developing lead molecules against several diseases. Due to the surge in research on bioactive molecules from algae, industries have started showing interest in patenting for the large-scale production of bioactive compounds having applications in sectors like pharmaceuticals, food, and beverage. In the food industry, algae are used as a thickening, gelling, and stabilizing agent. Due to their gelling and thickening characteristics, the most valuable algae products are macroalgal polysaccharides such as agar, alginates, and carrageenan. The high protein, lipid, and nutrient content in microalgae makes it a superfood for aquaculture. The present review aims at describing various non-energy-based applications of algae in pharmaceuticals, food and beverage, cosmetics, and nutraceuticals. This review attempts to analyze information on algal-derived drugs that have shown better potential and reached clinical trials.

Carotenoid Extraction from Plant Tissues

Carotenoids are the natural pigments available in nature and exhibit different colors such as yellow, red, and orange. These are a class of phytonutrients that have anti-cancer, anti-inflammatory, anti-oxidant, immune-modulatory, and anti-aging properties. These were used in food, pharmaceutical, nutraceutical, and cosmetic industries. They are divided into two classes: carotenes and xanthophylls. The carotenes are non-oxygenated derivatives and xanthophylls are oxygenated derivatives. The major source of carotenoids are vegetables, fruits, and tissues. Carotenoids also perform the roles of photoprotection and photosynthesis. In addition to the roles mentioned above, they are also involved and act as precursor molecules for the biosynthesis of phytohormones such as strigolactone and abscisic acid. This chapter briefly introduces carotenoids and their extraction method from plant tissue. Proposed protocol describes the extraction of carotenoid using solvents chloroform and dichloromethane. Reverse-phase HPLC can be performed with C30 columns using gradient elution. The column C30 is preferred to the C18 column because the C30 column has salient features, which include selective nature in the separation of structural isomers and hydrophobic, long-chain compounds, and shows the best compatibility with highly aqueous mobile phases. A complete pipeline for the extraction of carotenoids from plant tissue is given in the present protocol.

Progress and prospect: Biosynthesis of plant natural products based on plant chassis

Plant-derived natural products are a specific class of active substances with numerous applications in the medical, energy, and industrial fields. Many of these substances are in high demand and have become the fundamental materials for various purposes. Recently, the use of synthetic biology to produce plant-derived natural products has become a significant trend. Plant chassis, in particular, offer unique advantages over microbial chassis in terms of cell structure, product affinity, safety, and storage. The development of the plant hairy root tissue culture system has accelerated the commercialization and industrialization of synthetic biology in the production of plant-derived natural products. This paper will present recent progress in the synthesis of various plant natural products using plant chassis, organized by the types of different structures. Additionally, we will summarize the four primary types of plant chassis used for synthesizing natural products from plant sources and review the enabling technologies that have contributed to the development of synthetic biology in recent years. Finally, we will present the role of isolated and combined use of different optimization strategies in breaking the upper limit of natural product production in plant chassis. This review aims to provide practical references for synthetic biologists and highlight the great commercial potential of plant chassis biosynthesis, such as hairy roots.

Role of Nanoparticle-Conjugates and Nanotheranostics in Abrogating Oxidative Stress and Ameliorating Neuroinflammation

Oxidative stress is a deteriorating condition that arises due to an imbalance between the reactive oxygen species and the antioxidant system or defense of the body. The key reasons for the development of such conditions are malfunctioning of various cell organelles, such as mitochondria, endoplasmic reticulum, and Golgi complex, as well as physical and mental disturbances. The nervous system has a relatively high utilization of oxygen, thus making it particularly vulnerable to oxidative stress, which eventually leads to neuronal atrophy and death. This advances the development of neuroinflammation and neurodegeneration-associated disorders such as Alzheimer's disease, Parkinson's disease, epilepsy, dementia, and other memory disorders. It is imperative to treat such conditions as early as possible before they worsen and progress to irreversible damage. Oxidative damage can be negated by two mechanisms: improving the cellular defense system or providing exogenous antioxidants. Natural antioxidants can normally handle such oxidative stress, but they have limited efficacy. The valuable features of nanoparticles and/or nanomaterials, in combination with antioxidant features, offer innovative nanotheranostic tools as potential therapeutic modalities. Hence, this review aims to represent novel therapeutic approaches like utilizing nanoparticles with antioxidant properties and nanotheranostics as delivery systems for potential therapeutic applications in various neuroinflammation- and neurodegeneration-associated disease conditions.

A Narrative Review: The Effect and Importance of Carotenoids on Aging and Aging-Related Diseases

Aging is generally defined as a time-dependent functional decline that affects most living organisms. The positive increase in life expectancy has brought along aging-related diseases. Oxidative stress caused by the imbalance between pro-oxidants and antioxidants can be given as one of the causes of aging. At the same time, the increase in oxidative stress and reactive oxygen species (ROS) is main reason for the increase in aging-related diseases such as cardiovascular, neurodegenerative, liver, skin, and eye diseases and diabetes. Carotenoids, a natural compound, can be used to change the course of aging and aging-related diseases, thanks to their highly effective oxygen-quenching and ROS-scavenging properties. Therefore, in this narrative review, conducted using the PubMed, ScienceDirect, and Google Scholar databases and complying with the Scale for the Assessment of Narrative Review Articles (SANRA) guidelines, the effects of carotenoids on aging and aging-related diseases were analyzed. Carotenoids are fat-soluble, highly unsaturated pigments that occur naturally in plants, fungi, algae, and photosynthetic bacteria. A large number of works have been conducted on carotenoids in relation to aging and aging-related diseases. Animal and human studies have found that carotenoids can significantly reduce obesity and fatty liver, lower blood sugar, and improve liver fibrosis in cirrhosis, as well as reduce the risk of cardiovascular disease and erythema formation, while also lowering glycated hemoglobin and fasting plasma glucose levels. Carotenoid supplementation may be effective in preventing and delaying aging and aging-related diseases, preventing and treating eye fatigue and dry eye disease, and improving macular function. These pigments can be used to stop, delay, or treat aging-related diseases due to their powerful antioxidant, restorative, anti-proliferative, anti-inflammatory, and anti-aging properties. As an increasingly aging population emerges globally, this review could provide an important prospective contribution to public health.

Synthesis, DFT Study, and In Vitro Evaluation of Antioxidant Properties and Cytotoxic and Cytoprotective Effects of New Hydrazones on SH-SY5Y Neuroblastoma Cell Lines

A series of ten new hydrazide-hydrazone derivatives bearing a pyrrole ring were synthesized and structurally elucidated through appropriate spectral characteristics. The target hydrazones were assessed for radical scavenging activity through 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) tests, with ethyl 5-(4-bromophenyl)-1-(2-(2-(4-hydroxy-3,5-dimethoxybenzylidene)hydrazine-yl)-2-oxoethyl)-2-methyl-1H-pyrrole-3-carboxylate (7d) and ethyl 5-(4-bromophenyl)-1-(3-(2-(4-hydroxy-3,5-dimethoxybenzylidene) hydra zine-yl)-3-oxopropyl)-2-methyl-1H-pyrrole-3-carboxylate (8d) highlighted as the best radical scavengers from the series. Additional density functional theory (DFT) studies have indicated that the best radical scavenging ligands in the newly synthesized molecules are stable, do not decompose into elements, are less polarizable, and with a hard nature. The energy of the highest occupied molecular orbital (HOMO) revealed that both compounds possess good electron donation capacities. Overall, 7d and 8d can readily scavenge free radicals in biological systems via the donation of hydrogen atoms and single electron transfer. The performed in vitro assessment of the compound's protective activity on the H2O2-induced oxidative stress model on human neuroblastoma cell line SH-SY5Y determined 7d as the most perspective representative with the lowest cellular toxicity and the highest protection.

Xanthophyll pigments dietary supplements administration and retinal health in the context of increasing life expectancy trend

Introduction

Medicine faces nowadays the trend of increasing life expectancy of human population, with the resulting increase of degenerative age related diseases prevalence, combined with the risks of less tempered sun radiations environment exposure. Under these circumstances, our work pointed out on evaluating the effect of some xanthophyll pigments dietary supplements, actually widely recommended, for prevention of retinal degenerative damages and for slowing down the progression of such age related changes if they have already occurred. These dietary supplements are already well known for their total antioxidant activity, proven by photochemiluminescence method using Total Antioxidant Capacity in Lipid soluble-substances procedure.

Materials and methods

The study recruited a number of 120 subjects equally divided on genders. The lot included a first group of 60 patients with comparable ages (all of them over 50 years and divided in 2 segments of age: 50-60 and over 60) and suffering from comparable retinal age-related degenerative abnormalities (mild/medium severity age-related macular degeneration according to Wisconsin Age-Related Maculopathy Grading System), and a second group, considered control, including a similar number of healthy, normal retina subjects belonging to same age and gender categories. There were evaluated at baseline the eye medical status and the retinal risk by specific methods: complete eye check-up, Amsler grid, specific standardized questionnaires focused on visual function and its impact on the quality of current life. Both groups, patients and control, received similar dosages of xanthophyll pigments dietary supplements including lutein and zeaxanthin during 18 months after baseline; at the end of this supplementation period a new evaluation was conducted. In the second part of the research all subjects involved received a new dietary supplement in which the same xanthophylls were enriched with C and E vitamins and oligo-elements Zinc and Copper. At the end of three years duration supplementation, the subjects were reevaluated and the paper presents the conclusions on the matter, pointing on the impact of xanthophyll supplements on visual health.

Results

Correlation tests were applied to the complete set of data. Correlation tests have values between -1 and +1. The value -1 represents the negative correlation (reverse proportionality) meanwhile the value +1 represents the positive correlation (direct proportionality). The charts show the curves that are fitting experimental data. The dependence is linear in nature, and the value R2, as it approaches more the value 1, represents a better match with the experimental data (the data are in a percentage of approximately 99% on these straight lines of type y = ax + b). In the charts, there were noted the average values of the scores for healthy control patients with "Control", and the average values of the scores for the patients with existing age related degenerative retinal pathology at baseline with "Patients".

Discussion

The retinal function and the impact of visual condition on health were both evaluated at baseline, 18 months and 36 months after baseline, by visual acuity, ophthalmoscopy fundus examination, Amsler test and by asking the subjects to answer the visual function questionnaires: EQ-5D, NEI-VFQ-25, as measures of health status quality and of the influence on welfare. The study revealed that under supplementation both control healthy subjects and patients with known degenerative retinal pathology included in the 50-60 years of age group evolved almost the same way, leading to the conclusion that administered xanthophyll pigments-based supplements, simple or enriched, managed to slow down the progression of abnormal degenerative vision loss to a rate comparable to physiological aging-related vision loss. It was also observed that intake of xanthophyll pigments dietary supplements preserved the general health condition and maintained relatively constant vision on the entire 36th months follow-up research duration in patients presented with existing age related degenerative retinal pathology at baseline. For healthy subjects, evaluation showed an improvement in results after dietary supplementation, with maintenance of constant vision and a significantly increase of general condition, in a positive sense. For subjects over the age of 60 dietary supplements intake was even more effective compared to younger group in providing better control of degenerative processes.

Mechanistic Understanding of the Antiviral Properties of Pistachios and Zeaxanthin against HSV-1

The search for alternative clinical treatments to fight resistance and find alternative antiviral treatments for the herpes simplex virus (HSV) is of great interest. Plants are rich sources of novel antiviral, pharmacologically active agents that provide several advantages, including reduced side effects, less resistance, low toxicity, and different mechanisms of action. In the present work, the antiviral activity of Californian natural raw (NRRE) and roasted unsalted (RURE) pistachio polyphenols-rich extracts was evaluated against HSV-1 using VERO cells. Two different extraction methods, with or without n-hexane, were used. Results showed that n-hexane-extracted NRRE and RURE exerted an antiviral effect against HSV-1, blocking virus binding on the cell surface, affecting viral DNA synthesis as well as accumulation of ICP0, UL42, and Us11 viral proteins. Additionally, the identification and quantification of phenolic compounds by RP-HPLC-DAD confirmed that extraction with n-hexane exclusively accumulated tocopherols, carotenoids, and xanthophylls. Amongst these, zeaxanthin exhibited strong antiviral activity against HSV-1 (CC50: 16.1 µM, EC50 4.08 µM, SI 3.96), affecting both the viral attachment and penetration and viral DNA synthesis. Zeaxanthin is a dietary carotenoid that accumulates in the retina as a macular pigment. The use of pistachio extracts and derivates should be encouraged for the topical treatment of ocular herpetic infections.

β-carotene-loaded nanoparticles protect against neuromotor damage, oxidative stress, and dopamine deficits in a model of Parkinson's disease in Drosophila melanogaster

β-carotene-loaded nanoparticles improves absorption by increasing bioavailability. The Drosophila melanogaster model of Parkinson's disease must be helpful in investigating potential neuroprotective effects. Four groups of four-day-old flies were exposed to: (1) control; (2) diet containing rotenone (500 μM); (3) β-carotene-loaded nanoparticles (20 μM); (4) β-carotene-loaded nanoparticles and rotenone for 7 days. Then, the percentage of survival, geotaxis tests, open field, aversive phototaxis and food consumption were evaluated. At the end of the behaviors, the analyses of the levels of reactive species (ROS), thiobarbituric acid reactive substances (TBARS), catalase (CAT) and superoxide dismutase (SOD) activity was carried out, as well as an evaluation of the levels of dopamine and acetylcholinesterase (AChE) activity, in the head of flies. Nanoparticles loaded with β-carotene were able to improve motor function, memory, survival and also restored the oxidative stress indicators (CAT, SOD, ROS and TBARS), dopamine levels, AChE activity after exposure to rotenone. Overall, nanoparticles loaded with β-carotene showed significant neuroprotective effect against damage induced by the Parkinson-like disease model, emerging as a possible treatment. Overall, β-carotene-loaded nanoparticles presented significant neuroprotective effect against damage induced by model of Parkinson-like disease, emerging as a possible treatment.

Carotenoids: Role in Neurodegenerative Diseases Remediation

Numerous factors can contribute to the development of neurodegenerative disorders (NDs), such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis. Oxidative stress (OS), a fairly common ND symptom, can be caused by more reactive oxygen species being made. In addition, the pathological state of NDs, which includes a high number of protein aggregates, could make chronic inflammation worse by activating microglia. Carotenoids, often known as "CTs", are pigments that exist naturally and play a vital role in the prevention of several brain illnesses. CTs are organic pigments with major significance in ND prevention. More than 600 CTs have been discovered in nature, and they may be found in a wide variety of creatures. Different forms of CTs are responsible for the red, yellow, and orange pigments seen in many animals and plants. Because of their unique structure, CTs exhibit a wide range of bioactive effects, such as anti-inflammatory and antioxidant effects. The preventive effects of CTs have led researchers to find a strong correlation between CT levels in the body and the avoidance and treatment of several ailments, including NDs. To further understand the connection between OS, neuroinflammation, and NDs, a literature review has been compiled. In addition, we have focused on the anti-inflammatory and antioxidant properties of CTs for the treatment and management of NDs.

Intranasal Lipid Nanoparticles Containing Bioactive Compounds Obtained from Marine Sources to Manage Neurodegenerative Diseases

Marine sources contain several bioactive compounds with high therapeutic potential, such as remarkable antioxidant activity that can reduce oxidative stress related to the pathogenesis of neurodegenerative diseases. Indeed, there has been a growing interest in these natural sources, especially those resulting from the processing of marine organisms (i.e., marine bio-waste), to obtain natural antioxidants as an alternative to synthetic antioxidants in a sustainable approach to promote circularity by recovering and creating value from these bio-wastes. However, despite their expected potential to prevent, delay, or treat neurodegenerative diseases, antioxidant compounds may have difficulty reaching the brain due to the need to cross the blood–brain barrier (BBB). In this regard, alternative delivery systems administered by different routes have been proposed, including intranasal administration of lipid nanoparticles, such as solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), which have shown promising results. Intranasal administration shows several advantages, including the fact that molecules do not need to cross the BBB to reach the central nervous system (CNS), as they can be transported directly from the nasal cavity to the brain (i.e., nose-to-brain transport). The benefits of using SLN and NLC for intranasal delivery of natural bioactive compounds for the treatment of neurodegenerative diseases have shown relevant outcomes through in vitro and in vivo studies. Noteworthy, for bioactive compounds obtained from marine bio-waste, few studies have been reported, showing the open potential of this research area. This review updates the state of the art of using SLN and NLC to transport bioactive compounds from different sources, in particular, those obtained from marine bio-waste, and their potential application in the treatment of neurodegenerative diseases.

Natural Bioactive Molecules as Neuromedicines for the Treatment/Prevention of Neurodegenerative Diseases

The brain is vulnerable to different types of stresses, particularly oxidative stress as a result of oxygen requirements/utilization in the body. Large amounts of unsaturated fatty acids present in the brain increase this vulnerability. Neurodegenerative diseases (NDDs) are brain disorders that are characterized by the gradual loss of specific neurons and are attributed to broad evidence of cell-level oxidative stress. The accurate characterization of neurological disorders relies on several parameters along with genetics and environmental risk factors, making therapies less efficient to fight NDDs. On the way to tackle oxidative damage and discover efficient and safe therapies, bioactives are at the edge of NDD science. Naturally occurring bioactive compounds such as polyphenols, carotenoids, essential fatty acids, phytosterols, essential oils, etc. are particularly of interest owing to their potent antioxidant and anti-inflammatory activities, and they offer lots of brain-health-promoting features. This Review focuses on probing the neuroefficacy and bioefficacy of bioactives and their role in supporting relatively low antioxidative and low regenerative capacities of the brain, neurogenesis, neuroprotection, and ameliorating/treating NDDs.

A Review on Phyto-Therapeutic Approaches in Alzheimer's Disease

Neurodegenerative diseases occur due to progressive and sometimes irreversible loss of function and death of nerve cells. A great deal of effort is being made to understand the pathogenesis of neurodegenerative diseases. In particular, the prevalence of Alzheimer's disease (AD) is quite high, and only symptomatic therapy is available due to the absence of radical treatment. The aim of this review is to try to elucidate the general pathogenesis of AD, to provide information about the limit points of symptomatic treatment approaches, and to emphasize the potential neurologic effects of phytocompounds as new tools as therapeutic agents for disease prevention, retardation, and therapy. This survey also covers the notable properties of herbal compounds such as their effects on the inhibition of an enzyme called acetylcholinesterase, which has significant value in the treatment of AD. It has been proven that phytopharmaceuticals have long-term effects that could protect nervous system health, eliminate inflammatory responses, improve cognitive damage, provide anti-aging effects in the natural aging process, and alleviate dementia sequelae. Herbal-based therapeutic agents can afford many advantages and can be used as potentially as new-generation therapeutics or complementary agents with high compliance, fewer adverse effects, and lower cost in comparison to the traditional pharmaceutical agents in the fight against AD.

Effects of chronic consumption of specific fruit (berries, cherries and citrus) on cognitive health: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVES

The cognitive-protective effects related to the consumption of a variety of fruits are supported by several intervention studies. This systematic review and meta-analysis compared the magnitude of effects following chronic (≥1 week) consumption of frozen, freeze-dried powder including extracts and juices of fruits, covering berries, cherries and citrus, on cognition and mood in adults.

METHODS

PubMed, Web of Science, Scopus, and psycARTICLES were searched from inception until February, 2021. Inclusion criteria were randomised controlled trials assessing memory, executive function, psychomotor speed, mood and mini mental state examination in adult participants ≥18 years of age. Cognition was tested by global or domain specific tasks.

RESULTS

Out of 13,861 articles identified, 16 papers were included; 11 studies provided suitable data for meta-analysis. Fourteen studies reported improvement or trend for improvement in cognition, five studies assessed mood and one study supplementing grape juice found trend for mood improvement. From the meta-analysis, cherry juice supplementation was suggested to improve psychomotor speed by -0.37 of standardised mean difference (95% CI [-0.74, 0.01]) in reaction time (P = 0.05).

CONCLUSIONS

The meta-analysis did not sufficiently support a role for fruits or fruit forms to improve cognition and mood.

In Vitro Study of the Blood-Brain Barrier Transport of Natural Compounds Recovered from Agrifood By-Products and Microalgae

Agrifood by-products and microalgae represent a low-cost and valuable source of bioactive compounds with neuroprotective properties. However, the neuroprotective effectiveness of therapeutic molecules can be limited by their capacity to cross the blood-brain barrier (BBB) and reach the brain. In this research, various green extracts from Robinia pseudoacacia (ASFE), Cyphomandra betacea (T33), Coffea arabica (PPC1), Olea europaea L., (OL-SS), Citrus sinensis (PLE100) by-products and from the microalgae Dunaliella salina (DS) that have demonstrated in vitro neuroprotective potential were submitted to an in vitro BBB permeability and transport assay based on an immortalized human brain microvascular endothelial cells (HBMEC) model. Toxicity and BBB integrity tests were performed, and the transport of target bioactive molecules across the BBB were evaluated after 2 and 4 h of incubation using gas and liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (GC/LC-Q-TOF-MS). The HBMEC-BBB transport assay revealed a high permeability of representative neuroprotective compounds, such as mono- and sesquiterpenoids, phytosterols and some phenolic compounds. The obtained results from the proposed in vitro BBB cellular model provide further evidence of the neuroprotective potential of the target natural extracts, which represent a promising source of functional ingredients to be transferred into food supplements, food additives, or nutraceuticals with scientifically supported neuroprotective claims.

Crocin: Functional characteristics, extraction, food applications and efficacy against brain related disorders

Crocin is a bioactive compound that naturally occurs in some medicinal plants, especially saffron and gardenia fruit. Different conventional and novel methods are used for its extraction. Due to some control conditions, recent methods such as ultrasonic extraction, supercritical fluid extraction, enzyme-associated extraction, microwave extraction, and pulsed electric field extraction are widely used because these methods give more yield and efficiency. Crocin is incorporated into different food products to make functional foods. However, it can also aid in the stability of food products. Due to its ability to protect against brain diseases, the demand for crocin has been rising in the pharmaceutical industry. It also contain antioxidant, anti-inflammatory, anticancer and antidepressant qualities. This review aims to describe crocin and its role in developing functional food, extraction, and bioavailability in various brain-related diseases. The results of the literature strongly support the importance of crocin against various diseases and its use in making different functional foods.

The Identification and Quantitative Analysis of Unusual Keto-Carotenoids in Ripe Fruits of Maclura tricuspidate and Its Potential as a Valuable Source of Cryptocapsin

Ripe fruits of Maclura tricuspidata (MT) are used as food material and a natural colorant in Korea. Although MT fruits have a deep red color due to carotenoid-like pigments, their chemical nature has not been explored in detail so far. The present study aimed at elucidating the chemical structures and composition of carotenoids in MT fruits and changes at different maturity stages. Two carotenoids from saponified MT fruit extract were isolated using repeated silica gel column chromatography. Based on interpretations of spectroscopic data, these compounds were determined as keto-carotenoids, i.e., capsanthin (3,3'-dihydroxy-β,κ-caroten-6'-one) and cryptocapsin (3'-hydroxy-β,κ-caroten-6'-one), and the contents of individual carotenoids were quantified with HPLC based on calibration curves obtained from authentic standards. The contents of capsanthin and cryptocapsin in the sample of saponified MT fruits were 57.65 ± 1.97 µg/g and 171.66 ± 4.85 μg/g as dry weight base (dw). The majority of these keto-carotenoids in the MT fruits were present in esterified forms with lauric, myristic or palmitic acid rather than in their free forms. The results also showed that esterification of these compounds occurred starting from early stage (yellow-brownish stage) of maturation. Considering the high cryptocapsin content, MT fruits can be applied as a potentially valuable source of cryptocapsin for food and medicinal application as well as a source of provitamin A.

Oxidative Stress in Traumatic Brain Injury

Traumatic Brain Injury (TBI) remains a major cause of disability worldwide. It involves a complex neurometabolic cascade, including oxidative stress. The products of this manuscript is examining the underlying pathophysiological mechanism, including reactive oxygen species (ROS) and reactive nitrogen species (RNS). This process in turn leads to secondary injury cascade, which includes lipid peroxidation products. These reactions ultimately play a key role in chronic inflammation and synaptic dysfunction in a synergistic fashion. Although there are no FDA approved antioxidant therapy for TBI, there is a number of antioxidant therapies that have been tested and include free radical scavengers, activators of antioxidant systems, inhibitors of free radical generating enzymes, and antioxidant enzymes. Antioxidant therapies have led to cognitive and functional recovery post TBI, and they offer a promising treatment option for patients recovering from TBI. Current major challenges in treatment of TBI symptoms include heterogenous nature of injury, as well as access to timely treatment post injury. The inherent benefits of antioxidant therapies include minimally reported side effects, and relative ease of use in the clinical setting. The current review also provides a highlight of the more studied anti-oxidant regimen with applicability for TBI treatment with potential use in the real clinical setting.

β-carotene genetically-enriched lyophilized orange juice increases antioxidant capacity and reduces β-amyloid proteotoxicity and fat accumulation in Caenorhabditis elegans

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β-carotene content of genetically modified orange was 33-fold higher.

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β-carotene-enriched LOJ provided greater antioxidant capacity and stress resistance.

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β-carotene-enriched LOJ reduced β-amyloid proteotoxicity.

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β-carotene-enriched LOJ showed higher hypolipidemic activity in glucose rich diet.

Citrus sinensis orange juice is an excellent dietary source of β-carotene, a well-known antioxidant. However, β-carotene concentrations are relatively low in most cultivars. We developed a new orange through metabolic engineering strategy (GS) with 33.72-fold increase in β-carotene content compared to its conventional counterpart (CV). Using Caenorhabditis elegans, we found that animals treated with GS showed a greater reduction in intracellular reactive oxygen species (ROS) which is associated with a greater resistance to oxidative stress and induction of the expression of antioxidant genes. Moreover, animals treated with GS orange showed a more effective protection against β-amyloid proteotoxicity and greater hypolipidemic effect under high glucose diet compared to animals treated with CV. These data demonstrate that the increased amount of β-carotene in orange actually provides a greater beneficial effect in C. elegans and a valuable proof of principle to support further studies in mammals and humans.

Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities

Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.

Anthocyanins and Carotenoids Characterization in Flowers and Leaves of Cyclamen Genotypes Linked with Bioactivities Using Multivariate Analysis Techniques

The present study was carried out to evaluate and compare in vitro antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP)), antimicrobial, anticancer activities, and the individual carotenoids and anthocyanins content of methanol extracts of the Cyclamen genotypes: Persian cyclamen accessions (Cyclamen persicum Mill.), sowbread (C. mirabile Hildebr.), and ivy-leaved cyclamen (C. hederifolium Mill.) aerial parts. The HPLC-PDA analysis revealed the presence of five individual carotenoids (i.e., neoxanthin, violaxanthin, lutein, β-carotene, and cis-β-carotene) as the main compounds in Cyclamen leaves, and the presence of seven individual anthocycanins (i.e., cyanidin 3,5-di-O-glucoside, peonidin-rutinoside, peonidin 3,5-di-O-glucoside, peonidin 3-O-glucoside, malvidin 3-O-glucoside, malvidin 3,5-di-O-glucoside, and malvidin-rutinoside) in Cyclamen flowers reported, hereby, for the first time. The highest phenolic content was found in the leaves of LC6, C. mirabile (46.32 ± 0.14 mg/g gallic acid equivalents [GAE]), and in the flowers of C. persicum Merengue Magenta (FC15) (58.63 ± 0.17 mg/g GAE), whereas the highest flavonoid content was reported in C. persicum Halios Falbala leaves, namely LC9 (54.90 ± 0.27 mg/g quercetin equivalents [QE]) and in flowers of C. persicum Victora (FC2) (77.87 ± 0.25 mg/g QE). The highest antioxidant activity in DPPH and FRAP assays was reported in C. persicum Dark Violet (LC1) and Victoria (LC2), whereas C. mirabile (LC6) had the highest activity in the TEAC assay. In flowers, high antioxidant activities in DPPH and TEAC were noticed in C. persicum Superserie Red (FC7) and Dark Violet (FC1), respectively, and Halios Falbala (FC9) exhibited the highest activity in the TEAC assay. Additionally, FC9 exhibited the highest antibacterial activity in almost all tested bacteria compared with the leaves extracts. Furthermore, the highest in vitro citotoxicity in MDA-MB-231 cells was noticed in C. hederifolium LC18 (56.71-69.35%) and FC18 (40.07-41.43%), with a lower effect against BJ cells demonstrating selective toxicity. The above findings, highlight the potential use of the Cyclamen flower and leaf extracts as significant anticancer agents along with their antioxidant and antimicrobial properties.

Biological Potential, Gastrointestinal Digestion, Absorption, and Bioavailability of Algae-Derived Compounds with Neuroprotective Activity: A Comprehensive Review

Currently, there is no known cure for neurodegenerative disease. However, the available therapies aim to manage some of the symptoms of the disease. Human neurodegenerative diseases are a heterogeneous group of illnesses characterized by progressive loss of neuronal cells and nervous system dysfunction related to several mechanisms such as protein aggregation, neuroinflammation, oxidative stress, and neurotransmission dysfunction. Neuroprotective compounds are essential in the prevention and management of neurodegenerative diseases. This review will focus on the neurodegeneration mechanisms and the compounds (proteins, polyunsaturated fatty acids (PUFAs), polysaccharides, carotenoids, phycobiliproteins, phenolic compounds, among others) present in seaweeds that have shown in vivo and in vitro neuroprotective activity. Additionally, it will cover the recent findings on the neuroprotective effects of bioactive compounds from macroalgae, with a focus on their biological potential and possible mechanism of action, including microbiota modulation. Furthermore, gastrointestinal digestion, absorption, and bioavailability will be discussed. Moreover, the clinical trials using seaweed-based drugs or extracts to treat neurodegenerative disorders will be presented, showing the real potential and limitations that a specific metabolite or extract may have as a new therapeutic agent considering the recent approval of a seaweed-based drug to treat Alzheimer’s disease.

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review

Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.

Cytoprotective and Antigenotoxic Properties of Organic vs. Conventional Tomato Puree: Evidence in Zebrafish Model

In this in vivo study, we investigated cytoprotective and antigenotoxic effects of commercial tomato puree obtained from conventional vs. organic farming systems (pesticides vs. pesticide-free agriculture, respectively). This is relevant as pesticides are widely used in agriculture to prevent pests, weeds, and the spread of plant pathogens. By exposing zebrafish to tomato puree alone and in combination with H2O2 (a well-known genotoxic agent), we analyzed the percentage of fish survival, cell viability, intracellular concentration of reactive oxygen species (ROS), DNA fragmentation index (DFI%), and genomic template stability (GTS%). Fish exposed to organic puree showed higher fish survival and cellular viability, lower DFI% and ROS, and improved GTS%. Our results suggest a higher cytoprotective and antigenotoxic effect of organic pesticide-free tomatoes, probably because the activity of natural phytochemicals is not affected by the presence of toxic residues, which are otherwise produced by pesticides used in conventional farming systems. Our study points out the importance of considering alternative strategies in agriculture to minimize the genotoxic impact of chemical pesticides.

Nutraceuticals as Modulators of Autophagy: Relevance in Parkinson’s Disease

Dietary supplements and nutraceuticals have entered the mainstream. Especially in the media, they are strongly advertised as safe and even recommended for certain diseases. Although they may support conventional therapy, sometimes these substances can have unexpected side effects. This review is particularly focused on the modulation of autophagy by selected vitamins and nutraceuticals, and their relevance in the treatment of neurodegenerative diseases, especially Parkinson’s disease (PD). Autophagy is crucial in PD; thus, the induction of autophagy may alleviate the course of the disease by reducing the so-called Lewy bodies. Hence, we believe that those substances could be used in prevention and support of conventional therapy of neurodegenerative diseases. This review will shed some light on their ability to modulate the autophagy.

Tomatoes: An Extensive Review of the Associated Health Impacts of Tomatoes and Factors That Can Affect Their Cultivation

Simple Summary

The research outlined in this review paper discusses potential health benefits associated with a diet enriched with tomatoes and tomato products. This includes details of previous studies investigating the anticancer properties of tomatoes, protection against cardiovascular and neurodegenerative diseases and diabetes, maintenance of a healthy gut microbiome, and improved skin health, fertility, immune response, and exercise recovery. The specific parts of a tomato fruit that contribute these health benefits are also outlined. The potential disadvantages to a tomato-rich diet are detailed, especially the consumption of supplements that contain compounds found in tomatoes, such as lycopene. This review also discusses how the cultivation of tomato plants can affect the nutritional value of the fruit harvested. Different environmental growing conditions such as light intensity, growing media, and temperature are explained in terms of the impact they have on the quality of fruit, its nutrient content, and hence the potential health benefits acquired from eating the fruit.

Abstract

This review outlines the health benefits associated with the regular consumption of tomatoes and tomato products. The first section provides a detailed account of the horticultural techniques that can impact the quality of the fruit and its nutritional properties, including water availability, light intensity, temperature, and growing media. The next section provides information on the components of tomato that are likely to contribute to its health effects. The review then details some of the health benefits associated with tomato consumption, including anticancer properties, cardiovascular and neurodegenerative diseases and skin health. This review also discusses the impact tomatoes can have on the gut microbiome and associated health benefits, including reducing the risk of inflammatory bowel diseases. Other health benefits of eating tomatoes are also discussed in relation to effects on diabetes, the immune response, exercise recovery, and fertility. Finally, this review also addresses the negative effects that can occur as a result of overconsumption of tomato products and lycopene supplements.

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.

Carotenoids: Therapeutic Strategy in the Battle against Viral Emerging Diseases, COVID-19: An Overview

Carotenoids, a group of phytochemicals, are naturally found in the Plant kingdom, particularly in fruits, vegetables, and algae. There are more than 600 types of carotenoids, some of which are thought to prevent disease, mainly through their antioxidant properties. Carotenoids exhibit several biological and pharmaceutical benefits, such as anti-inflammatory, anti-cancer, and immunity booster properties, particularly as some carotenoids can be converted into vitamin A in the body. However, humans cannot synthesize carotenoids and need to obtain them from their diets or via supplementation. The emerging zoonotic virus severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), originated in bats, and was transmitted to humans. COVID-19 continues to cause devastating international health problems worldwide. Therefore, natural preventive therapeutic strategies from bioactive compounds, such as carotenoids, should be appraised for strengthening physiological functions against emerging viruses. This review summarizes the most important carotenoids for human health and enhancing immunity, and their potential role in COVID-19 and its related symptoms. In conclusion, promising roles of carotenoids as treatments against emerging disease and related symptoms are highlighted, most of which have been heavily premeditated in studies conducted on several viral infections, including COVID-19. Further in vitro and in vivo research is required before carotenoids can be considered as potent drugs against such emerging diseases.

Pre- and Early Post-treatment With Arthrospira platensis (Spirulina) Extract Impedes Lipopolysaccharide-triggered Neuroinflammation in Microglia

Background: Uncontrolled neuroinflammation and microglia activation lead to cellular and tissue damage contributing to neurodegenerative and neurological disorders. Spirulina (Arthrospira platensis (Nordstedt) Gomont, or Spirulina platensis), a blue-green microalga, which belongs to the class of cyanobacteria, has been studied for its numerous health benefits, which include anti-inflammatory properties, among others. Furthermore, in vivo studies have highlighted neuroprotective effects of Spirulina from neuroinflammatory insults in different brain areas. However, the mechanisms underlying the anti-inflammatory effect of the microalga are not completely understood. In this study we examined the effect of pre- and post-treatment with an acetone extract of Spirulina (E1) in an in vitro model of LPS-induced microglia activation.

Methods: The effect of E1 on the release of IL-1β and TNF-α, expression of iNOS, nuclear factor erythroid 2–related factor 2 (Nrf2), and heme oxygenase-1 (HO-1), and the activation of NF-κB was investigated in primary microglia by ELISA, real-time PCR, and immunofluorescence.

Results: Pre- and early post-treatment with non-cytotoxic concentrations of E1 down-regulated the release of IL-1β and TNF-α, and the over-expression of iNOS induced by LPS. E1 also significantly blocked the LPS-induced nuclear translocation of NF-κB p65 subunit, and upregulated gene and protein levels of Nrf2, as well as gene expression of HO-1.

Conclusions: These results indicate that the extract of Spirulina can be useful in the control of microglia activation and neuroinflammatory processes. This evidence can support future in vivo studies to test pre- and post-treatment effects of the acetone extract from Spirulina.

PLGA-PEG Nanoparticles Facilitate In Vivo Anti-Alzheimer's Effects of Fucoxanthin, a Marine Carotenoid Derived from Edible Brown Algae

The marine natural product fucoxanthin has been reported previously to produce anti-Alzheimer's disease (AD) neuroprotective effects in vitro and in vivo. Fucoxanthin was also demonstrated to be safe in preclinical and small population clinical studies, but the low bioavailability of fucoxanthin in the central nervous system (CNS) has limited its clinical applications. To overcome this, poly lactic-co-glycolic acid-block-polyethylene glycol loaded fucoxanthin (PLGA-PEG-Fuc) nanoparticles with diameter at around 200 nm and negative charge were synthesized and suggested to penetrate into the CNS. Loaded fucoxanthin could be liberated from PLGA-PEG nanoparticles by sustained released in the physiological environment. PLGA-PEG-Fuc nanoparticles were shown to significantly inhibit the formation of Aβ fibrils and oligomers. Moreover, these nanoparticles were taken up by both neurons and microglia, leading to the reduction of Aβ oligomers-induced neurotoxicity in vitro. Most importantly, intravenous injection of PLGA-PEG-Fuc nanoparticles prevented cognitive impairments in Aβ oligomers-induced AD mice with greater efficacy than free fucoxanthin, possibly via acting on Nrf2 and NF-κB signaling pathways. These results altogether suggest that PLGA-PEG nanoparticles can enhance the bioavailability of fucoxanthin and potentiate its efficacy for the treatment of AD, thus potentially enabling its future use for AD therapy.

Microencapsulation of carotenoid-rich materials: A review

Carotenoids are natural pigments that present several bioactive properties, including antioxidant, anticarcinogenic and provitamin A activities. However, these compounds are susceptible to degradation when exposed to a number of conditions (e.g. light, heat, oxygen), leading to loss of benefits and hampering their application in food products. Their hydrophobicity also makes incorporation into water-based foods more difficult. Microencapsulation techniques have been applied for decades to provide stability to carotenoid-rich extracts under typical conditions of processing and storage of foods, besides offering several other advantages to the use and application of these materials. This work reviews the recent advances in the microencapsulation of carotenoid-rich extracts, oils and oleoresins from varying sources, evidencing the technologies applied to encapsulate these materials, the effects of encapsulation on the obtained particles, and the impact of such processes on the bioaccessibility and release profile of carotenoids from microparticles. Moreover, recent applications of carotenoid-rich microparticles in food products are discussed. Most of the applied processes were effective in improving different aspects of the encapsulated materials, especially the stability of carotenoids during storage, resulting in microparticles with promising properties for future applications in food products. However, the lack of information about the effects of microencapsulation on carotenoids during processing of model foods, the sensory acceptance of enriched food products and the bioaccessibility and bioavailability of microencapsulated carotenoids reveals gaps that should be explored in the future.

Antioxidant and Signal-Modulating Effects of Brown Seaweed-Derived Compounds against Oxidative Stress-Associated Pathology

The biological and therapeutic properties of seaweeds have already been well known. Several studies showed that among the various natural marine sources of antioxidants, seaweeds have become a potential source of antioxidants because of their bioactive compounds. Most of the metabolic diseases are caused by oxidative stress. It is very well known that antioxidants have a pivotal role in the treatment of those diseases. Recent researches have revealed the potential activity of seaweeds as complementary medicine, which have therapeutic properties for health and disease management. Among the seaweeds, brown seaweeds (Phaeophyta) and their derived bioactive substances showed excellent antioxidant properties than other seaweeds. This review focuses on brown seaweeds and their derived major bioactive compounds such as sulfated polysaccharide, polyphenol, carotenoid, and sterol antioxidant effects and molecular mechanisms in the case of the oxidative stress-originated disease. Antioxidants have a potential role in the modification of stress-induced signaling pathways along with the activation of the oxidative defensive pathways. This review would help to provide the basis for further studies to researchers on the potential antioxidant role in the field of medical health care and future drug development.

Therapeutic potential of astaxanthin and superoxide dismutase in Alzheimer's disease

Oxidative stress, the imbalance of the antioxidant system, results in an accumulation of neurotoxic proteins in Alzheimer's disease (AD). The antioxidant system is composed of exogenous and endogenous antioxidants to maintain homeostasis. Superoxide dismutase (SOD) is an endogenous enzymatic antioxidant that converts superoxide ions to hydrogen peroxide in cells. SOD supplementation in mice prevented cognitive decline in stress-induced cells by reducing lipid peroxidation and maintaining neurogenesis in the hippocampus. Furthermore, SOD decreased expression of BACE1 while reducing plaque burden in the brain. Additionally, Astaxanthin (AST), a potent exogenous carotenoid, scavenges superoxide anion radicals. Mice treated with AST showed slower memory decline and decreased depositions of amyloid-beta (Aβ) and tau protein. Currently, the neuroprotective potential of these supplements has only been examined separately in studies. However, a single antioxidant cannot sufficiently resist oxidative damage to the brain, therefore, a combinatory approach is proposed as a relevant therapy for ameliorating pathological changes in AD.

Computational Evaluation of Interaction Between Curcumin Derivatives and Amyloid-β Monomers and Fibrils: Relevance to Alzheimer's Disease

BACKGROUND

The most important hallmark in the neuropathology of Alzheimer's disease (AD) is the formation of amyloid-β (Aβ) fibrils due to the misfolding/aggregation of the Aβ peptide. Preventing or reverting the aggregation process has been an active area of research. Naturally occurring products are a potential source of molecules that may be able to inhibit Aβ42 peptide aggregation. Recently, we and others reported the anti-aggregating properties of curcumin and some of its derivatives in vitro, presenting an important therapeutic avenue by enhancing these properties.

OBJECTIVE

To computationally assess the interaction between Aβ peptide and a set of curcumin derivatives previously explored in experimental assays.

METHODS

The interactions of ten ligands with Aβ monomers were studied by combining molecular dynamics and molecular docking simulations. We present the in silico evaluation of the interaction between these derivatives and the Aβ42 peptide, both in the monomeric and fibril forms.

RESULTS

The results show that a single substitution in curcumin could significantly enhance the interaction between the derivatives and the Aβ42 monomers when compared to a double substitution. In addition, the molecular docking simulations showed that the interaction between the curcumin derivatives and the Aβ42 monomers occur in a region critical for peptide aggregation.

CONCLUSION

Results showed that a single substitution in curcumin improved the interaction of the ligands with the Aβ monomer more so than a double substitution. Our molecular docking studies thus provide important insights for further developing/validating novel curcumin-derived molecules with high therapeutic potential for AD.

Neuroprotective Natural Products for Alzheimer's Disease

Alzheimer's disease (AD) is the number one neurovegetative disease, but its treatment options are relatively few and ineffective. In efforts to discover new strategies for AD therapy, natural products have aroused interest in the research community and in the pharmaceutical industry for their neuroprotective activity, targeting different pathological mechanisms associated with AD. A wide variety of natural products from different origins have been evaluated preclinically and clinically for their neuroprotective mechanisms in preventing and attenuating the multifactorial pathologies of AD. This review mainly focuses on the possible neuroprotective mechanisms from natural products that may be beneficial in AD treatment and the natural product mixtures or extracts from different sources that have demonstrated neuroprotective activity in preclinical and/or clinical studies. It is believed that natural product mixtures or extracts containing multiple bioactive compounds that can work additively or synergistically to exhibit multiple neuroprotective mechanisms might be an effective approach in AD drug discovery.

Carotenoid Extract Derived from Euglena gracilis Overcomes Lipopolysaccharide-Induced Neuroinflammation in Microglia: Role of NF-κB and Nrf2 Signaling Pathways

Activation of microglia results in the increased production and release of a series of inflammatory and neurotoxic mediators, which play essential roles in structural and functional neuronal damage and in the development and progression of a number of neurodegenerative diseases. The microalga Euglena gracilis (Euglena), rich in vitamins, minerals, and other nutrients, has gained increasing attention due to its antimicrobial, anti-viral, antitumor, and anti-inflammatory activities. In particular, anti-inflammatory properties of Euglena could exert neuroprotective functions in different neurodegenerative diseases related to inflammation. However, the mechanisms underlying the anti-inflammatory effect of Euglena are not fully understood. In this study, we investigated whether Euglena could attenuate microglia activation and we also studied the mechanism of its anti-inflammatory activity. Our results showed that non-cytotoxic concentrations of a Euglena acetone extract (EAE) downregulated the mRNA expression levels and release of pro-inflammatory mediators, including NO, IL-1β, and TNF-α in LPS-stimulated microglia. EAE also significantly blocked the LPS-induced nuclear translocation of NF-κB p65 subunit and increased the mRNA expression of nuclear factor erythroid 2–related factor (Nrf2) and heme oxygenase-1 (HO-1). Furthermore, the release of pro-inflammatory mediators and NF-κB activation were also blocked by EAE in the presence of ML385, a specific Nrf2 inhibitor. Together, these results show that EAE overcomes LPS-induced microglia pro-inflammatory responses through downregulation of NF-κB and activation of Nrf2 signaling pathways, although the two pathways seem to get involved in an independent manner.

A narrative review on the potential of tomato and lycopene for the prevention of Alzheimer's disease and other dementias

Oxidative stress is a major factor in aging and is implicated in the pathogenesis of tumors, diabetes mellitus, cardiovascular and neurodegenerative diseases, including Alzheimer Disease (AD). Bioactive constituents of tomato as polyphenols and carotenoids, among which lycopene (LYC) are effective in reducing markers of oxidative stress, and appear to have a protective modulator role on the pathogenetic mechanisms, cognitive symptoms and behavioral manifestations of these diseases in cell cultures and animal models. Epidemiological evidence indicates a consistent association between the intake of tomatoes and reduced cardiovascular and neoplastic risk. LYC deficiency is common in elders and AD patients and it is strongly predictive of mortality and poor cardiovascular (CV) outcomes. Dietary intake of tomatoes seems to be more effective than tomato/LYC supplementation. Limited evidence from human intervention trials suggests that increasing tomato intake, besides improving CV markers, enhances cognitive performances. In this narrative review, we analyze the existing evidence on the beneficial effects of tomatoes on AD-related processes or risk factors. Results support the development of promising nutritional strategies to increase the levels of tomato consumption for the prevention or treatment of AD and other dementias. Extensive well-structured research, however, is mandatory to confirm the neuroprotective effects of tomato/LYC in humans.

Plasma carotenoids and medial temporal lobe atrophy in older adults

BACKGROUND & AIMS

Carotenoids are vegetable pigments with neuroprotective properties. Clinical studies found efficacy of specific carotenoids on improving brain perfusion and functioning with aging. However, evidence of an effect on neurodegeneration, which may require longer follow-up period to observe, is more limited. Leveraging biomarkers from a large population-based cohort study of older adults, we investigated whether blood carotenoids were associated with atrophy of the medial temporal lobe (a biomarker of neurodegeneration in aging) over 10 years.

METHODS

This study included 461 dementia-free participants from the Three-City Bordeaux study (aged ≥65) who had plasma carotenoids measured at baseline and up to three repeated brain imaging exams in the subsequent 10 years.

RESULTS

In adjusted linear mixed models, each increase of 1 SD in plasma level of total carotenoids and of β-carotene was associated with 0.02 cm³ (95% CI, 0.001-0.04; P = 0.04) and 0.02 cm³ (95% CI, 0.01-0.04; P = 0.008) smaller medial temporal lobe volume loss per year, respectively.

CONCLUSIONS

Our results based on a unique long-term prospective evaluation of a neuroimaging biomarker suggest a beneficial role of carotenoids for the prevention of age-related neurodegeneration.

Carotenoids and Cognitive Outcomes: A Meta-Analysis of Randomized Intervention Trials

Recent evidence suggests that diet can modify the risk of future cognitive impairment and dementia. A biologically plausible rationale and initial clinical data indicate that the antioxidant activities of dietary carotenoids may assist the preservation of cognitive function. A meta-analysis of randomized controlled trials was conducted to examine the relationship between carotenoid supplementation and cognitive performance. A literature search was conducted in the MEDLINE (via PubMed), Scopus, Web of Science, and Cochrane databases from their inception to July 2020. A total of 435 studies were retrieved. Abstract screening using predefined inclusion and exclusion criteria was followed by full-text screening and data extraction of study characteristics and measured outcomes. A meta-analysis of eligible trials was performed using a random-effects model to estimate pooled effect size. We identified 9 studies with a total of 4402 nondemented subjects, whose age ranged from 45 to 78 years. Results of the pooled meta-analysis found a significant effect of carotenoid intervention on cognitive outcomes (Hedge’s g = 0.14; 95% confidence interval: 0.08, 0.20, p < 0.0001). There was no evidence of heterogeneity among the studies (τ2 = 0.00, I² = 0.00%, H² = 1.00) or publication bias. Although further studies are needed, our results suggest that carotenoid interventions are associated with better cognitive performance. Thus, these dietary compounds may help to reduce the risk of cognitive impairment and dementia.

Age-Related Macular Degeneration: What Do We Know So Far?

Ageing is a natural process that everyone experiences and nobody is an exception. With ageing, our body experiences physiological changes. In this article, the focus is made on the physiological changes of our eyes related to ageing and age-related macular degeneration (AMD), which is the most common cause of incurable visual impairment in developed countries. With ageing populations increasing in many countries, more and more patients will have AMD in a foreseeable future. In Eastern Europe, blindness due to AMD, currently, is approximately 20% and there has been an increasing trend depicted in the future. Generally, AMD can be divided into early stages and two forms in an advanced (late) stage. Advanced AMD form includes neovascular AMD (wet) and geographic atrophy (late dry), both of these are associated with substantial, progressive visual impairment. The pathogenesis of AMD is complex and, by far, not completely understood. Multiple factors have been studied, for example: environmental factor, genetic factor (complement factor H), lifestyle. It has been proved that they are linked to higher the risk of developing of AMD, however, the actual pathogenesis is not yet formulated. AMD progression can also be a culprit to certain biochemical events and molecular changes linked to inflammation and pathological angiogenesis. In nowadays, we do have diagnostic methods for both early and late forms of AMD as well as ways to prevent progression of early AMD and wet AMD. However, until now, there is still no treatment for dry AMD. This article is a brief review of AMD and may hopefully lead to some future directions in early diagnostic methods and treating dry AMD.

Polyphenols as Potential Metal Chelation Compounds Against Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative disease affecting more than 50 million people worldwide. The pathology of this multifactorial disease is primarily characterized by the formation of amyloid-β (Aβ) aggregates; however, other etiological factors including metal dyshomeostasis, specifically copper (Cu), zinc (Zn), and iron (Fe), play critical role in disease progression. Because these transition metal ions are important for cellular function, their imbalance can cause oxidative stress that leads to cellular death and eventual cognitive decay. Importantly, these transition metal ions can interact with the amyloid-β protein precursor (AβPP) and Aβ42 peptide, affecting Aβ aggregation and increasing its neurotoxicity. Considering how metal dyshomeostasis may substantially contribute to AD, this review discusses polyphenols and the underlying chemical principles that may enable them to act as natural chelators. Furthermore, polyphenols have various therapeutic effects, including antioxidant activity, metal chelation, mitochondrial function, and anti-amyloidogenic activity. These combined therapeutic effects of polyphenols make them strong candidates for a moderate chelation-based therapy for AD.

Chili Pepper Carotenoids: Nutraceutical Properties and Mechanisms of Action

Chili pepper is a prominent cultivated horticultural crop that is traditionally used for food seasoning and is applied for the treatment and prevention of multiple diseases. Its beneficial health properties are due to its abundance and variety of bioactive components, such as carotenoids, capsaicinoids, and vitamins. In particular, carotenoids have important nutraceutical properties, and several studies have focused on their potential in the prevention and treatment of human diseases. In this article, we reviewed the state of knowledge of general aspects of chili pepper carotenoids (biosynthesis pathway, types and content in Capsicum spp., and the effects of processing on carotenoid content) and recent findings on the effects of carotenoid nutraceuticals, such as antioxidant, cancer preventive, anti-inflammatory, cardiovascular disorder preventive, and anti-obesity effects.

Metabolic Analysis of Carotenoids and Phenolic Compounds Found in Green and Purple Kenaf

The chemical composition of the different plant parts of green ( Hibiscus cannabinus L. cv. Jangdae) and purple ( H. cannabinus L. cv. Jeokbong) kenaf cultivars were investigated using high-performance liquid chromatography. Ten carotenoid and phenolic compounds were quantified in the different parts of green and purple kenaf. The accumulation of carotenoids and phenolic compounds in the different parts of both cultivars was slightly different. The total carotenoid content in all parts of purple kenaf was higher than that in green kenaf. In particular, lutein, β-carotene, and 9Z-β-carotene were found in all the plant parts of both purple and green kenaf. Most levels of these 3 carotenoids were higher in all parts of the purple cultivar than those found in the green cultivar. According to the detected phenolic compound content, the leaves of the green cultivar contained a higher level of total phenolics, even though the most levels of the individual phenolic compounds were higher in the purple cultivar due to the level of kaempferitrin, a major compound found in kenaf, being much higher than the levels observed for the other phenolic compounds. However, the flowers and stems of the purple cultivar had a higher level of total phenolics. Among the 10 different phenolic compounds, 7 (4-hydroxybenzoic acid, chlorogenic acid, p-coumaric acid, ferulic acid, benzoic acid, rutin, and kaempferol) were present in all the plant parts of both kenaf cultivars. Purple kenaf leaves contain higher levels of 4-hydroxybenzoic acid, chlorogenic acid, and rutin, whereas the purple cultivar flowers have higher levels of p-coumaric acid, ferulic acid, and benzoic acid. This study provides valuable information on the chemical composition of different plant parts of green and purple kenaf cultivars.