Antioxidant activity and polyphenol content in cultivated and wild edible fruits grown in Panama

Wild vs. Cultivated Zingiber striolatum Diels: Nutritional and Biological Activity Differences

Compositional, functional, and nutritional properties are important for the use-value assessments of wild and cultivated edible plants. The aim of this study was to compare the nutritional composition, bioactive compounds, volatile compounds, and potential biological activities of cultivated and wild Zingiber striolatum. Various substances, such as soluble sugars, mineral elements, vitamins, total phenolics, total flavonoids, and volatiles, were measured and analyzed using UV spectrophotometry, ICP-OES, HPLC, and GC-MS methods. The antioxidant capacity of a methanol extract of Z. striolatum, as well as the hypoglycemic abilities of its ethanol and water extracts, were tested. The results showed that the contents of soluble sugar, soluble protein, and total saponin in the cultivated samples were higher, while the wild samples contained higher amounts of K, Na, Se, vitamin C, and total amino acids. The cultivated Z. striolatum also showed a higher antioxidant potential, while the wild Z. striolatum exhibited a better hypoglycemic activity. Thirty-three volatile compounds were identified using GC-MS in two plants, with esters and hydrocarbons being the main volatile compounds. This study demonstrated that both cultivated and wild Z. striolatum have a good nutritional value and biological activity, and can be used as a source of nutritional supplementation or even in medication.

Phytotherapeutic Approaches to the Prevention of Age-Related Changes and the Extension of Active Longevity

Maintaining quality of life with an increase in life expectancy is considered one of the global problems of our time. This review explores the possibility of using natural plant compounds with antioxidant, anti-inflammatory, anti-glycation, and anti-neurodegenerative properties to slow down the onset of age-related changes. Age-related changes such as a decrease in mental abilities, the development of inflammatory processes, and increased risk of developing type 2 diabetes have a significant impact on maintaining quality of life. Herbal preparations can play an essential role in preventing and treating neurodegenerative diseases that accompany age-related changes, including Alzheimer’s and Parkinson’s diseases. Medicinal plants have known sedative, muscle relaxant, neuroprotective, nootropic, and antiparkinsonian properties. The secondary metabolites, mainly polyphenolic compounds, are valuable substances for the development of new anti-inflammatory and hypoglycemic agents. Understanding how mixtures of plants and their biologically active substances work together to achieve a specific biological effect can help develop targeted drugs to prevent diseases associated with aging and age-related changes. Understanding the mechanisms of the biological activity of plant complexes and mixtures determines the prospects for using metabolomic and biochemical methods to prolong active longevity.

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.

Quantitative Assessment of Abiotic Stress on the Main Functional Phytochemicals and Antioxidant Capacity of Wheatgrass at Different Seedling Age

The wheat seedlings of 6 days old were daily subjected to ultraviolet irradiation (irradiating for 5, 10, 20, 40, and 60 min/day, respectively), Polyethylene glycol 6000 (5, 10, 15, 20, 25% in 1/2 Hoagland solution, respectively), and salinity solution (10, 25, 50, 100, 200 mM in 1/2 Hoagland solution, respectively), while the control group (CK) was supplied only with the Hoagland solution. The wheatgrass was harvested regularly seven times and the total soluble polysaccharides, ascorbic acid, chlorophyll, total polyphenol, total triterpene, total flavonoid, and proanthocyanins content were tested. The antioxidant capacity was evaluated through 2,2'-azino-bis (3-ethylbenzthia-zoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and ferric ion reducing power. Technique for order preference by similarity to ideal solution (TOPSIS) mathematical model was adopted to comprehensively assess the functional phytochemicals of the different treatments. The results showed that the accumulation patterns of phytochemicals under abiotic stress were complex and not always upregulated or downregulated. The antioxidant activity and functional phytochemicals content of wheatgrass were significantly affected by both the stress treatments and seedling age, while the latter affected the chemicals more efficiently. The top five highest functional phytochemicals were observed in the 200 mM NaCl treated group on the 21st and 27th day, 25% PEG treated group on the 24th day, 200 mM NaCl treated group on the 24th day, and the group of 40 min/day ultraviolet exposure on 27th day.

LC-ESI-QTOF-MS/MS Profiling and Antioxidant Activity of Phenolics from Custard Apple Fruit and By-Products

Custard apple is an edible fruit grown in tropical and subtropical regions. Due to its abundant nutrient content and perceived health benefits, it is a popular food for consumption and is utilized as a medicinal aid. Although some published research had provided the phenolic compound of custard apple, the comprehensive phenolic profiling of Australian grown custard apple is limited. Hence, this research aimed to evaluate the phenolic content and antioxidant potential by various phenolic content and antioxidant assays, followed by characterization and quantification of the phenolic profile using LC-ESI-QTOF-MS/MS and HPLC-PDA. African Pride peel had the highest value in TPC (61.69 ± 1.48 mg GAE/g), TFC (0.42 ± 0.01 mg QE/g) and TTC (43.25 ± 6.70 mg CE/g), followed by Pink’s Mammoth peel (19.37 ± 1.48 mg GAE/g for TPC, 0.27 ± 0.03 mg QE/g for TFC and 10.25 ± 1.13 mg CE/g for TTC). African Pride peel also exhibited the highest antioxidant potential for TAC (43.41 ± 1.66 mg AAE/g), FRAP (3.60 ± 0.14 mg AAE/g) and ABTS (127.67 ± 4.60 mg AAE/g), whereas Pink’s Mammoth peel had the highest DPPH (16.09 ± 0.34 mg AAE/g), RPA (5.32 ± 0.14 mg AAE/g), •OH-RSA (1.23 ± 0.25 mg AAE/g) and FICA (3.17 ± 0.18 mg EDTA/g). LC-ESI-QTOF-MS/MS experiment successfully characterized 85 phenolic compounds in total, encompassing phenolic acids (20), flavonoids (42), stilbenes (4), lignans (6) and other polyphenols (13) in all three parts (pulp, peel and seeds) of custard apple. The phenolic compounds in different portions of custard apples were quantified by HPLC-PDA, and it was shown that African Pride peel had higher concentrations of the most abundant phenolics. This is the first study to provide the comprehensive phenolic profile of Australian grown custard apples, and the results highlight that each part of custard apple can be a rich source of phenolics for the utilization of custard apple fruit and waste in the food, animal feeding and nutraceutical industries.

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.

Comparative evaluation of chemical composition and biological activities of tropical fruits consumed in Manaus, central Amazonia, Brazil

Fruits are widely recognized as sources of biologically active metabolites, such as antioxidant compounds. In this context, fruits commonly consumed in the central Amazonia, especially in its biggest metropolis (Manaus - AM/Brazil), are attractive as potential sources of antioxidant compounds related to biological activities. Most of such fruits are still poorly studied and/or remain unknown outside the Amazon region. Therefore, this study aims to investigate nine fruits (abiu, cubiu, biribá, breadfruit, genipap, peach palm, murici, soursop, and umari) regarding their chemical composition (fixed and volatile), reducing capacity, antioxidant activity, enzyme inhibition, and cytotoxicity. Determination of small organic acids, hydroxycinnamic acids, flavan-3-ols and flavonoid aglycones was done by HPLC-MS/MS, whereas determination of volatile organic compounds (VOCs) was done by HS-SPME/GC-MS. Reducing capacity was determined by the Folin-Ciocalteu method, and antioxidant activities were evaluated by DPPH, ABTS, and H-ORAC_FL assays. In vitro activities regarding inhibition of enzymes were tested for α-glucosidase, lipase, and α-amylase, and anti-glycation activities were evaluated for methylglyoxal and fructose. Cytotoxicity of fruit extracts was evaluated by cell viability of human fibroblast cell line (MRC-5). A total of 16 antioxidant compounds and 139 VOCs were determined, whose profiles were unique for each studied fruit. Total phenolic contents as well as antioxidant activities found herein were similar or even higher than those reported for several traditional fruits. Some of fruit extracts were able to inhibit α-glucosidase and glycation in methylglyoxal and fructose models, whereas none of them was active for lipase and α-amylase. All of the fruit extracts showed to be non-cytotoxic to MRC-5 cell line.

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.

Phenolic profile (HPLC-UV) analysis and biological activities of two organic extracts from Echinops spinosissimus Turra roots growing in Tunisia

Echinops spinosissimus Turra subsp. roots was investigated, after extraction with two different solvents: ethanol and ethyl acetate, for its phenolic profile as well as biological activities. Echinops spinosissimus Turra subsp. spinosus roots ethanolic extract was characterized by the highest content of total polyphenols (19.3 mg GAE/100 g of DW). In addition, the phenolic profiles of the two studied extracts were analysed using HPLC-UV, where p-coumaric (8.59 mg/kg of DW) and cinnamic acids (4.68 mg/kg of DW) were detected as the most abundant phenolic acids, and kaempferol was the predominant flavonoids (30.37 mg/kg of DM) followed by quercetin and rutin in the ethanolic extract. While, only p-coumaric acid, epicatechin, kaempferol and quercetin were identified and quantified in ethyl acetate roots extract. All tested extracts exhibited an antimicrobial effect against Gram-positive and Gram-negative bacteria. These findings indicate that Echinops spinosissimus Turra subsp. spinosus roots can be regarded as a new source of edible oil having health benefits and nutritional properties.

Passiflora edulis: An Insight Into Current Researches on Phytochemistry and Pharmacology

Passiflora edulis, also known as passion fruit, is widely distributed in tropical and subtropical areas of the world and becomes popular because of balanced nutrition and health benefits. Currently, more than 110 phytochemical constituents have been found and identified from the different plant parts of P. edulis in which flavonoids and triterpenoids held the biggest share. Various extracts, fruit juice and isolated compounds showed a wide range of health effects and biological activities such as antioxidant, anti-hypertensive, anti-tumor, antidiabetic, hypolipidemic activities, and so forth. Daily consumption of passion fruit at common doses is non-toxic and safe. P. edulis has great potential development and the vast future application for this economically important crop worldwide, and it is in great demand as a fresh product or a formula for food, health care products or medicines. This mini-review aims to provide systematically reorganized information on physiochemical features, nutritional benefits, biological activities, toxicity, and potential applications of leaves, stems, fruits, and peels of P. edulis.

Antioxidant Properties and Protective Effects of Some Species of the Annonaceae, Lamiaceae, and Geraniaceae Families against Neuronal Damage Induced by Excitotoxicity and Cerebral Ischemia

This study aimed to compare the antioxidant activities of extracts obtained from three plant families and evaluate their therapeutic effect on strokes. Ethanol extracts were obtained from either the leaf or the aerial parts of plants of the families Annonaceae (Annona cherimola, A. diversifolia, A. muricata, A. purpurea, and A. reticulata), Lamiaceae (Salvia amaríssima and S. polystachya), and Geraniaceae (Geranium niveum and G. mexicanum). Extracts were analyzed in terms of hydroxyl radical (OH•), peroxyl radical (ROO•), and superoxide anion (O2•-). The efficiency of the extracts to prevent neuronal death induced by excitotoxicity was tested with the tetrazolium assay, the O2•- scavenging capacity was evaluated with the dihydroethidium dye, and the protective effect of the extracts with the highest antioxidant activity was tested on a stroke experimental model. The extracts' IC50 values (μg/mL) of scavenging varied from 98.9 to 155.04, 4.5 to 102.4, and 20.2 to 118.97 for OH•, ROO•, and O2•-, respectively. In the excitotoxicity model, Annonaceae extracts were highly cytotoxic while Lamiaceae and Geraniaceae reduced intracellular O2•- production and protect neurons against oxidative stress. Salvia polystachya reduced cerebral damage, as well as improved survival and behavior after ischemia. Our results encouraged the use of plant extracts as natural antioxidants to minimize neuronal injury following stroke.

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.

Partnering with Panama: Exploring Anthropometrics, Dietary Patterns, and the Built Food Environment of School-aged Children

Childhood obesity is a global public health concern in developed and developing countries. Approximately 3 in 10 Panamanian children suffer from obesity, and overweight/obesity is responsible for the highest number of premature or avoidable deaths in this country. A formative community assessment and exploration of the built food environment was conducted. Analysis suggests that almost one-third of the children measured were overweight or obese, and the availability of foods recommended for optimal health is limited in this community. Actionable recommendations for intervention and future collaboration were provided, and stakeholders from all groups will continue to explore opportunities.

Classification of barberry genotypes by multivariate analysis of biochemical constituents and HPLC profiles

INTRODUCTION

Recently, there has been a growing interest in the use of edible barberry and their extracts as a source of natural antioxidants in food and pharmaceutical industries.

OBJECTIVE

The aim of this study was to evaluate the biochemical constituents of 18 samples of barberry fruits and classification of barberry genotypes by multivariate analysis.

METHODS

Total phenolic, total flavonoid, total anthocyanin, total tannin, total carbohydrate contents and antioxidant activity were determined using Folin-Ciocalteu, aluminum chloride, colorimetric, vanillin, anthron and DPPH (2,2'-diphenyl-1-picrylhydrazyl) assays, respectively. High-performance liquid chromatography (HPLC) system is used for quantitative determination of phytochemical constituents. The multivariate data analysis (principal component analysis and hierarchical cluster analysis) and heat map data visualisation techniques were performed to classify barberry genotypes using Minitab and GraphPad Prism software, respectively.

RESULTS

The highest amounts of total phenolics and flavonoids were obtained in fruit extracts of G3 (Berberis vulgaris). The highest total anthocyanin content and antioxidant activity were observed in G8 (B. vulgaris) and G16 (B. vulgaris), respectively. HPLC analysis of phytochemicals (gallic acid, caffeic acid, chlorogenic acid, p-coumaric acid, cinnamic acid, rutin, apigenin, and quercetin) revealed that gallic acid and p-coumaric acid were found as the most abundant phytochemical compounds. Based on multivariate analysis and heat map visualisation techniques, Berberis genotypes were classified into three main clusters.

CONCLUSIONS

These results showed that barberry species (especially B. vulgaris and B. carataegina) are promising sources of natural antioxidants and biochemical compounds beneficial to be used in the food industry and that the multivariate analysis was a suitable approach to classify the barberry samples.

Evaluation of Antioxidant Capacity, Protective Effect on Human Erythrocytes and Phenolic Compound Identification in Two Varieties of Plum Fruit (Spondias spp.) by UPLC-MS

Plum edible part was used to obtained extracts by during a 4 h maceration process using three different solvents (ethanol, methanol and water) for the determination of total phenols and flavonoids, antioxidant capacity by (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hemolysis inhibition in human blood assays. Subsequently, phenolic compounds were identified using ultra-performance liquid chromatography (UPLC-MS). The results indicated that the ethanolic extract of plum fruit being a good source of phenolic (12–18 mg GAE/g FW) and flavonoids (2.3–2.5 mg QE/g FW) content in both varieties of plum. Also, the fruits proved a good source of antioxidants as measured by DPPH and ABTS; likewise, plum aqueous extracts showed the highest protective effect on human erythrocytes with 74.34 and 64.62% for yellow and red plum, respectively. A total of 23 bioactive compounds were identified by UPLC-MS, including gallic acid, rutin, resorcinol, chlorogenic acid, catechin, and ellagic acid, and the antioxidant capacity can be attributed to these species. The edible part of plum contains compounds of biological interest, suggesting that this fruit has antioxidant potential that can be exploited for various technologies.

Current state of knowledge on the traditional uses, phytochemistry, and pharmacology of the genus Hymenaea

ETHNOPHARMACOLOGICAL RELEVANCE

Plants of the genus Hymenaea (Fabaceae) are used in South American and Asian traditional medicines to treat a multitude of disorders, like cough, diarrhea, dysentery, intestinal colic, pulmonary weakness, asthma, anemia, sore throat, and for the treatment of kidney problems, viral related disorders, chronic cystitis, bronchitis, and bladder infections. Some Hymenaea species are also used as vermifuge, and for the treatment of arthritis, and inflammation conditions. This review deals with updated information on the traditional uses, phytochemistry and pharmacology of ethnomedicinally important Hymenaea species in order to provide an input for the future research prospects.

METHODS

Literature available in various recognized databases including Google Scholar, PubMed, SciFinder, Scopus, Springer, Wiley, ACS, Scielo and Web of Science, as well as from theses, dissertations, books, reports, and other relevant websites (www.theplantlist.org), are surveyed, analysed, and included in this review. Herein, the literature related to chemical constituents and pharmacological activities were searched in November 2016.

RESULTS

The literature provided information on ethnopharmacological uses of the South American and African species of the genus Hymenaea (e.g., H. courbaril, H. stigonocarpa, H. onblogifolia, H. martiana, H. parvifolia (South America) and H. verrucosa (African species)) for the treatment of multi-factorial diseases. From these plant species, more than 130 compounds, including fatty acids, flavonoids, terpenoids and steroids, phthalides, phenolic acids, procyanidins and coumarins were identified. Experimental evidences confirmed that the Hymenaea spp. could be used in treating inflammatory disorders, asthma, diarrhea, and some microbial infections. However, reports on the toxicity of Hymenaea species remain scarce.

CONCLUSION

Plants of this genus have offered bioactive samples, both from crude extracts and pure compounds, thus substantiating their effectiveness in traditional medicine. However, intensive investigations of all the species of Hymenaea spp. relating to phytochemical and pharmacological properties, especially their mechanism of action, safety and efficacy could be the future introspection.

LC-QTOF-MS Analysis and Activity Profiles of Popular Antioxidant Dietary Supplements in Terms of Quality Control

The dietary supplements with claimed antioxidant activity constitute a substantial part of the dietary supplement market. In this study, we performed the LC-QTOF-MS analysis and investigated the activity profiles of popular antioxidant dietary supplements from different chemical groups in terms of quality control. The commonly used antioxidant tests and statistical analysis revealed that substantial part of the results was comparable if 1 g sample was considered, but while comparing single and daily doses, significant differences in antioxidant values were noticed in all assays. The best antioxidant activity was obtained in ORAC assay (from 142 to 13814 μM of Trolox equivalents per 1 g of sample), and the strongest correlation occurred between TPC and ORAC. The LC-QTOF-MS analysis revealed that catechins were present in samples having the best antioxidant activity and that dietary supplements showing the weakest activity contained very small amount of any chemical constituents.

A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador

Myopia is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P < .001). As hypothesized, when stratified by age (<40 and ≥ 40 years), Mann-Whitney U tests revealed that hunter-gatherers maintained high visual acuity throughout life, whereas agrarian visual acuity declined (P values < .001); visual acuity of younger participants was high across the board, however, did not differ between groups (P > .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age.

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.