Betalain health-promoting effects after ingestion in Caenorhabditis elegans are mediated by DAF-16/FOXO and SKN-1/Nrf2 transcription factors

Semisynthesis of Betaxanthins from Purified Betacyanin of Opuntia dillenii sp.: Color Stability and Antiradical Capacity

The availability of pure individual betalains in sufficient quantities which permit deeper understanding is still a challenge. This study investigates the high-yielding semisynthesis of betaxanthins using betalamic acid from a natural source (Opuntia dillenii), followed by condensation with ʟ-amino acids and further purification. Moreover, the color stability of the four synthesized individual betaxanthins, namely proline (ʟ-ProBX), alanine (ʟ-AlaBX), leucine (ʟ-LeuBX), and phenylalanine (ʟ-PheBX) betaxanthins, was investigated at different pHs. Their relative contribution to free radical scavenging was also scrutinized by TEAC and DPPH. ʟ-AlaBX and ʟ-LeuBx showed a significantly (p < 0.05) higher antioxidant activity, whereas ʟ-ProBX was the most resistant to the hydrolysis of betaxanthin and hence the least susceptible to color change. The color stability was strongly influenced by pH, with the color of ʟ-ProBX, ʟ-LeuBX, and ʟ-AlaBX at pH 6 being more stable, probably due to the easier hydrolysis under acid conditions. The semisynthesis and purification allowed us to have available remarkable quantities of pure individual betaxanthins of Opuntia dillenii for the first time, and to establish their color properties and antioxidant capacity. This study could be a step forward in the development of the best natural food colorant formulation, based on the betalain structure, which is of special interest in food technology.

Cyclocodon lancifolius fruit prolongs the lifespan of Caenorhabditis elegans via antioxidation and regulation of purine metabolism

Cyclocodon lancifolius fruit is a promising commercial fruit with antioxidant activity and is rich in polyphenolic compounds. In this study, the anti-aging activity of C. lancifolius fruit extract (CF) on Caenorhabditis elegans (C. elegans) was evaluated by observing the longevity, stress response, reproduction, oscillation, lipofuscin, and antioxidant enzymes of worms. Moreover, the effects and potential mechanisms of CF on delaying C. elegans senescence at the mRNA and metabolite levels were investigated. The results showed that CF treatment significantly increased the lifespan and stress resistance, decreased the levels of lipofuscin and reactive oxygen species (ROS), and improved the antioxidant system of C. elegans. The extension of the lifespan of C. elegans was remarkably correlated with the upregulation of mtl-1 and Hsp-16.2, along with the downregulation of age-1, daf-2, and akt-1. Metabolomics analysis revealed that purine metabolism is a key regulatory pathway for CF to exert anti-aging effects. The present study suggests that C. lancifolius fruit has potential for use as a functional food to enhance antioxidant capacity and delay aging.

Genomic Exploration: Unraveling the Intricacies of Indica Rice Oryza sativa L. Germin-Like Protein Gene 12-3 (OsGLP12-3) Promoter via Cloning, Sequencing, and In Silico Analysis

Germin and Germin-like proteins (GLPs) are a class of plant proteins that are part of the Cupins superfamily, found in several plant organs including roots, seeds, leaves, and nectar glands. They play a crucial role in plant defense against pathogens and environmental stresses. Herein, this study focused on the promoter analysis of OsGLP12-3 in rice cultivar Swat-1 to elucidate its regulation and functions. The region (1863bp) of the OsGLP12-3 promoter from Swat-1 genomic DNA was amplified, purified, quantified, and cloned using Topo cloning technology, followed by sequencing. Further in silico comparative analysis was conducted between the OsGLP12-3 promoters from Nipponbare and Swat-1 using the Plant CARE database, identifying 24 cis-acting regulatory elements with diverse functions. These elements exhibited distinct distribution patterns in the 2 rice varieties. The OsGLP12-3 promoter revealed an abundance of regulatory elements associated with biotic and abiotic stress responses. Computational tools were employed to analyze the regulatory features of this region. In silico expression analysis of OsGLP12-3, considering various developmental stages, stress conditions, hormones, and expression timing, was performed using the TENOR tool. Pairwise alignment indicated 86% sequence similarity between Nipponbare and Swat-1. Phylogenetic analysis was conducted to explore the evolutionary relationship between the OsGLP12-3 and other plant GLPs. Additionally, 2 unique regulatory elements were modeled and docked, GARE and MBS to understand their hydrogen bonding interactions in gene regulation. The study highlights the importance of OsGLP12-3 in plant defense against biotic and abiotic stresses, supported by its expression patterns in response to various stressors and the presence of specific regulatory elements within its promoter region.

The role of Caenorhabditis elegans in the discovery of natural products for healthy aging

Covering: 2012 to 2023The human population is aging. Thus, the greatest risk factor for numerous diseases, such as diabetes, cancer and neurodegenerative disorders, is increasing worldwide. Age-related diseases do not typically occur in isolation, but as a result of multi-factorial causes, which in turn require holistic approaches to identify and decipher the mode of action of potential remedies. With the advent of C. elegans as the primary model organism for aging, researchers now have a powerful in vivo tool for identifying and studying agents that effect lifespan and health span. Natural products have been focal research subjects in this respect. This review article covers key developments of the last decade (2012-2023) that have led to the discovery of natural products with healthy aging properties in C. elegans. We (i) discuss the state of knowledge on the effects of natural products on worm aging including methods, assays and involved pathways; (ii) analyze the literature on natural compounds in terms of their molecular properties and the translatability of effects on mammals; (iii) examine the literature on multi-component mixtures with special attention to the studied organisms, extraction methods and efforts regarding the characterization of their chemical composition and their bioactive components. (iv) We further propose to combine small in vivo model organisms such as C. elegans and sophisticated analytical approaches ("wormomics") to guide the way to dissect complex natural products with anti-aging properties.

Identification of WRKY gene family members in amaranth based on a transcriptome database and functional analysis of AtrWRKY42-2 in betalain metabolism

Introduction

WRKY TFs (WRKY transcription factors) contribute to the synthesis of secondary metabolites in plants. Betalains are natural pigments that do not coexist with anthocyanins within the same plant. Amaranthus tricolor ('Suxian No.1') is an important leaf vegetable rich in betalains. However, the WRKY family members in amaranth and their roles in betalain synthesis and metabolism are still unclear.

Methods

To elucidate the molecular characteristics of the amaranth WRKY gene family and its role in betalain synthesis, WRKY gene family members were screened and identified using amaranth transcriptome data, and their physicochemical properties, conserved domains, phylogenetic relationships, and conserved motifs were analyzed using bioinformatics methods.

Results

In total, 72 WRKY family members were identified from the amaranth transcriptome. Three WRKY genes involved in betalain synthesis were screened in the phylogenetic analysis of WRKY TFs. RT-qPCR showed that the expression levels of these three genes in red amaranth 'Suxian No.1' were higher than those in green amaranth 'Suxian No.2' and also showed that the expression level of AtrWRKY42 gene short-spliced transcript AtrWRKY42-2 in Amaranth 'Suxian No.1' was higher than that of the complete sequence AtrWRKY42-1, so the short-spliced transcript AtrWRKY42-2 was mainly expressed in 'Suxian No.2' amaranth. Moreover, the total expression levels of AtrWRKY42-1 and AtrWRKY42-2 were down-regulated after GA3 treatment, so AtrWRKY42-2 was identified as a candidate gene. Therefore, the short splice variant AtrWRKY42-2 cDNA sequence, gDNA sequence, and promoter sequence of AtrWRKY42 were cloned, and the PRI 101-AN-AtrWRKY42-2-EGFP vector was constructed to evaluate subcellular localization, revealing that AtrWRKY42-2 is located in the nucleus. The overexpression vector pRI 101-AN-AtrWRKY42-2-EGFP and VIGS (virus-induced gene silencing) vector pTRV2-AtrWRKY42-2 were transferred into leaves of 'Suxian No.1' by an Agrobacterium-mediated method. The results showed that AtrWRKY42-2 overexpression could promote the expression of AtrCYP76AD1 and increase betalain synthesis. A yeast one-hybrid assay demonstrated that AtrWRKY42-2 could bind to the AtrCYP76AD1 promoter to regulate betalain synthesis.

Discussion

This study lays a foundation for further exploring the function of AtrWRKY42-2 in betalain metabolism.

Betalains Alleviate Exercise-Induced Oxidative Stress, Inflammation, and Fatigue and Improve Sports Performance: an Update on Recent Advancement

PURPOSE OF REVIEW

Beetroot juice is a popular natural food supplement commonly consumed for its health and ergogenic benefits. It contains an abundance of phytochemical compounds, which have been shown to enhance sports endurance and recovery. Among them, nitrate is well-studied and known for improving performance during exercise. On the other hand, betalains, the bioactive pigment, have shown various biological activities including antioxidant, anti-inflammatory, and anti-hypertensive, which may improve exercise performance and post-exercise recovery. Additionally, free radical scavenging activities of betalains could increase nitric oxide availability in the blood, thereby improving blood flow and oxygen supply during strenuous exercise. This review article provides a critical discussion of the non-pathological conditions induced by prolonged or strenuous exercise and betalains' potential in reducing such conditions including muscle damage, inflammation, and fatigue. Additionally, the real-time application of betalains as an ergogenic compound in competitive athletes has been discussed. Finally, future directions and conclusions on the potential of betalains as a natural ergogenic aid in sport endurance are outlined.

RECENT FINDINGS

Betalains in beetroot are the major water-soluble nitrogen-containing pigment possessing high antioxidant, anti-inflammatory, and anti-fatigue activities. Betalain supplementation could alleviate exercise-induced oxidative stress, inflammation, and fatigue in competitive athletes. Betalains have the potential to become a natural ergogenic aid or nutraceutical compound for sports people during exercise and competitive performance.

Vitexin and isovitexin delayed ageing and enhanced stress-resistance through the activation of the SKN-1/Nrf2 signaling pathway

Vitexin and isovitexin, as potential SKN-1/Nrf2 (SKN-1 is a homologous protein of mammalian Nrf2) activators, extended lifespan and promoted healthspan in Caenorhabditis elegans. This study aims to elucidate the role of SKN-1/Nrf2 in vitexin and isovitexin-induced anti-aging and stress-resistance. Vitexin and isovitexin upregulated antioxidant gene and protein expressions, reduced ROS accumulation, and increased SKN-1 accumulation in the nucleus. They prolonged lifespan and clear ROS during stressful conditions in a skn-1-dependent manner. skn-1 was also found to be necessary for these compounds-induced longevity under normal conditions. They were also witnessed to retard cellular senescence and scavenge ROS in senescent cells by directly binding to the pocket of Keap1 to promote the dissociation and activation of Nrf2. This study showed that SKN-1/Nrf2 signaling was vital to delaying ageing and enhancing anti-stress capacity with vitexin and isovitexin. The findings provide new insights into apigenin C-glycosides activating the SKN-1/Nrf2 pathway and demonstrate their potential as candidates for innovative strategies in chemoprophylaxis against ageing and oxidative-related diseases.

Consumption of commonly used artificial food dyes increases activity and oxidative stress in the animal model Caenorhabditis elegans

In recent decades, the consumption of artificial colorants in foods and beverages has increased despite of concerns in the general population raised by studies that have shown possible injurious effects. In this study, tartrazine, sunset yellow, quinoline yellow, ponceau 4R, carmoisine and allura red were employed as pure compounds to explore their effects in vivo in the animal model Caenorhabditis elegans. The exposition of C. elegans to these artificial dyes produced damage related with aging such as oxidative stress and lipofuscin accumulation, as well as a heavy shortening of lifespan, alterations in movement patterns and alterations in the production of dopamine receptors. Besides, microarray analysis performed with worms treated with tartrazine and ponceau 4R showed how the consumption of synthetic colorants is able to alter the expression of genes involved in resistance to oxidative stress and neurodegeneration.

Characterization of betalain-loaded liposomes and its bioactive potential in vivo after ingestion

Betalains are plant pigments characterized by showing a wide range of beneficial properties for health. Its bioactive potential has been studied for the first time after its encapsulation in liposomes and subsequent administration to the animal model Caenorhabditis elegans. Phenylalanine-betaxanthin and indoline carboxylic acid-betacyanin encapsulated at concentrations of 25 and 500 μM managed to reduce lipid accumulation and oxidative stress in the nematodes. Highly antioxidant betalains dopaxanthin and betanidin were also included in the survival analyses. The results showed that phenylalanine-betaxanthin was the most effective betalain by increasing the lifespan of C. elegans by 21.8%. In addition, the administration of encapsulated natural betanidin increased the nematodes' survival rate by up to 13.8%. The preservation of the bioactive properties of betalains manifested in this study means that the stabilization of the plant pigments through encapsulation in liposomes can be postulated as a new way for administration in pharmacological and food applications.

Effects of Vegetal Extracts and Metabolites against Oxidative Stress and Associated Diseases: Studies in Caenorhabditis elegans

Oxidative stress is a natural physiological process where the levels of oxidants, such as reactive oxygen species (ROS) and nitrogen (RNS), exceed the strategy of antioxidant defenses, culminating in the interruption of redox signaling and control. Oxidative stress is associated with multiple pathologies, including premature aging, neurodegenerative diseases, obesity, diabetes, atherosclerosis, and arthritis. It is not yet clear whether oxidative stress is the cause or consequence of these diseases; however, it has been shown that using compounds with antioxidant properties, particularly compounds of natural origin, could prevent or slow down the progress of different pathologies. Within this context, the Caenorhabditis elegans (C. elegans) model has served to study the effect of different metabolites and natural compounds, which has helped to decipher molecular targets and the effect of these compounds on premature aging and some diseases such as neurodegenerative diseases and dyslipidemia. This article lists the studies carried out on C. elegans in which metabolites and natural extracts have been tested against oxidative stress and the pathologies associated with providing an overview of the discoveries in the redox area made with this nematode.

Biocolorants in food: Sources, extraction, applications and future prospects

Color of a food is one of the major factors influencing its acceptance by consumers. At presently synthetic dyes are the most commonly used food colorant in food industry by providing more esthetically appearance and as a means to quality control. However, the growing concern about health and environmental due to associated toxicity with synthetic food colorants has accelerated the global efforts to replace them with safer and healthy food colorants obtained from natural resources (plants, microorganisms, and animals). Further, many of these biocolorants not only provide myriad of colors to the food but also exert biological properties, thus they can be used as nutraceuticals in foods and beverages. In order to understand the importance of nature-derived pigments as food colorants, this review provides a thorough discussion on the natural origin of food colorants. Following this, different extraction methods for isolating biocolorants from plants and microbes were also discussed. Many of these biocolorants not only provide color, but also have many health promoting properties, for this reason their physicochemical and biological properties were also reviewed. Finally, current trends on the use of biocolorants in foods, and the challenges faced by the biocolorants in their effective utilization by food industry and possible solutions to these challenges were discussed.

Preparation of Dendrobium officinale Flower Anthocyanin and Extended Lifespan in Caenorhabditis elegans

The Dendrobium officinale flower is a non-medicinal part of the plant, rich in a variety of nutrients and bioactive ingredients. The purpose of this article was to explore the preparation conditions of anthocyanins (ACNs) from the D. officinale flower. Subsequently, its anti-aging effects were evaluated with Caenorhabditis elegans. Results showed that the ACNs had antioxidant activities on scavenging free radicals (DPPH· and ABTS⁺·), and the clearance rate was positively correlated with the dose. Additionally, ACNs significantly increased the activity of superoxide dismutase (SOD) in C. elegans, which was 2.068-fold higher than that of the control. Treatment with ACNs at 150 μL extended the lifespan of C. elegans by 56.25%, and treatment with ACNs at 50 μL promoted fecundity in C. elegans. Finally, the protective effect of ACNs enhanced stress resistance, thereby increasing the survival numbers of C. elegans, which provided insights for the development and practical application of functional products.

Redox Properties, Bioactivity and Health Effects of Indicaxanthin, a Bioavailable Phytochemical from Opuntia ficus indica, L.: A Critical Review of Accumulated Evidence and Perspectives

Phytochemicals from plant foods are considered essential to human health. Known for their role in the adaptation of plants to their environment, these compounds can induce adaptive responses in cells, many of which are directed at maintaining the redox tone. Indicaxanthin is a long-known betalain pigment found in the genus Opuntia of cactus pear and highly concentrated in the edible fruits of O. ficus indica, L. whose bioactivity has been overlooked until recently. This review summarizes studies conducted so far in vitro and in vivo, most of which have been performed in our laboratory. The chemical and physicochemical characteristics of Indicaxanthin are reflected in the molecule's reducing properties and antioxidant effects and help explain its ability to interact with membranes, modulate redox-regulated cellular pathways, and possibly bind to protein molecules. Measurement of bioavailability in volunteers has been key to exploring its bioactivity; amounts consistent with dietary intake, or plasma concentration after dietary consumption of cactus pear fruit, have been used in experimental setups mimicking physiological or pathophysiological conditions, in cells and in animals, finally suggesting pharmacological potential and relevance of Indicaxanthin as a nutraceutical. In reporting experimental results, this review also aimed to raise questions and seek insights for further basic research and health promotion applications.

Structural Effects on the Antioxidant Properties of Amino Acid Betaxanthins

Betaxanthins are natural products with high antioxidant and anti-inflammatory properties. Here, we describe the semisynthesis of twenty-one betaxanthins derived from proteinogenic amino acids, including the elusive betaxanthin of l-cysteine and two betaxanthins derived from l-lysine, and rationalize their antioxidant properties in mechanistic terms. The antioxidant capacity and redox potential of these betaxanthins were compared to those of model betaxanthins derived from dopamine, l-DOPA (L-3,4-dihydroxyphenylalanine), and pyrrolidine and structure–property relationships were established by using matched molecular pair analysis and a model developed using a genetic algorithm. Either a phenol or indole moiety enhance the antioxidant capacity of betaxanthins, which is overall much higher than that of their amino acid precursors and standard antioxidants, except for the cysteine-betaxanthin. The one-electron oxidation of amino acid betaxanthins produces radicals stabilized in multiple centers, as demonstrated by quantum chemical calculations.

Oolonghomobisflavans exert neuroprotective activities in cultured neuronal cells and anti-aging effects in Caenorhabditis elegans

Potential health benefits of tea has attracted significant scientific and public attention worldwide. Tea polyphenols are considered as natural promising complementary therapeutical agents for neurodegenerative diseases. However, the anti-neurodegeneration or anti-aging activities of oolong tea polyphenols have not been investigated. The current study aims to document beneficial effects of oolong tea polyphenols [dimers of epigallocatechin gallate (EGCG), oolonghomobisflavan A (OFA), and oolonghomobisflavan B (OFB)] with neuroprotective and neuritogenesis properties in cultured neuronal (Neuro-2a and HT22) cells and Caenorhabditis elegans models. In vitro, we found that the compounds (EGCG, OFA, and OFB) protect against glutamate-induced neurotoxicity via scavenging radical activity, suppression intracellular ROS and up-regulation of antioxidant enzymes. Moreover, the compounds induce neurite outgrowth via up-regulate Ten-4 gene expression. Interestingly, OFA and OFB exert stronger neuroprotective and neurite outgrowth properties than EGCG known as an excellent antioxidant agent in tea. In vivo, we found that the compounds protect against C. elegans Aβ-induced paralysis, chemotaxis deficiency and α-synuclein aggregation. Moreover, the compounds are capable of extending the lifespan of C. elegans. OFA and OFB possess both anti-neurodegeneration and anti-aging activities, supporting its therapeutic potential for the treatment of age-related neurodegenerative diseases which need to be studied in more detail in intervention studies.

Structural features and antioxidant activities of polysaccharides from different parts of Codonopsis pilosula var. modesta (Nannf.) L. T. Shen

In this study, three acidic polysaccharides from different plant parts of Codonopsis pilosula var. Modesta (Nannf.) L. T. Shen were obtained by ion exchange chromatography and gel filtration chromatography, and the yields of these three polysaccharides were different. According to the preliminary experimental results, the antioxidant activities of the polysaccharides from rhizomes and fibrous roots (CLFP-1) were poor, and was thus not studied further. Due to this the structural features of polysaccharides from roots (CLRP-1) and aerial parts (CLSP-1) were the object for this study and were structurally characterized, and their antioxidant activities were evaluated. As revealed by the results, the molecular weight of CLRP-1and CLSP-1 were 15.9 kDa and 26.4 kDa, respectively. The monosaccharide composition of CLRP-1 was Ara, Rha, Fuc, Xyl, Man, Gal, GlcA, GalA in a ratio of 3.8: 8.4: 1.0: 0.8: 2.4: 7.4: 7.5: 2.0: 66.7, and Ara, Rha, Gal, GalA in a ratio of 5.8: 8.9: 8.0: 77.0 in for CLSP-1. The results of structural elucidation indicated that both CLRP-1 and CLSP-1 were pectic polysaccharides, mainly composed of 1, 4-linked galacturonic acid with long homogalacturonan regions. Arabinogalactan type I and arabinogalactan type II were presented as side chains. The antioxidant assay in IPEC-J2 cells showed that both CLRP-1 and CLSP-1 promoted cell viability and antioxidant activity, which significantly increase the level of total antioxidant capacity and the activity of superoxide dismutase, catalase, and decrease the content of malondialdehyde. Moreover, CLRP-1 and CLSP-1 also showed powerful antioxidant abilities in Caenorhabditis elegans and might regulate the nuclear localization of DAF-16 transcription factor, induced antioxidant enzymes activities, and further reduced reactive oxygen species and malondialdehyde contents to increase the antioxidant ability of Caenorhabditis elegans. Thus, these finding suggest that CLRP-1 and CLSP-1 could be used as potential antioxidants.

A comprehensive review of beetroot (Beta vulgaris L.) bioactive components in the food and pharmaceutical industries

Beetroot is rich in various bioactive phytochemicals, which are beneficial for human health and exert protective effects against several disease conditions like cancer, atherosclerosis, etc. Beetroot has various therapeutic applications, including antioxidant, antibacterial, antiviral, and analgesic functions. Besides the pharmacological effects, food industries are trying to preserve beetroots or their phytochemicals using various food preservation methods, including drying and freezing, to preserve their antioxidant capacity. Beetroot is a functional food due to valuable active components such as minerals, amino acids, phenolic acid, flavonoid, betaxanthin, and betacyanin. Due to its stability, nontoxic and non-carcinogenic and nonpoisonous capabilities, beetroot has been used as an additive or preservative in food processing. Beetroot and its bioactive compounds are well reported to possess antioxidant, anti-inflammatory, antiapoptotic, antimicrobial, antiviral, etc. In this review, we provided updated details on (i) food processing, preservation and colorant methods using beetroot and its phytochemicals, (ii) synthesis and development of several nanoparticles using beetroot and its bioactive compounds against various diseases, (iii) the role of beetroot and its phytochemicals under disease conditions with molecular mechanisms. We have also discussed the role of other phytochemicals in beetroot and their health benefits. Recent technologies in food processing are also updated. We also addressed on molecular docking-assisted biological activity and screening for bioactive chemicals. Additionally, the role of betalain from different sources and its therapeutic effects have been listed. To the best of our knowledge, little or no work has been carried out on the impact of beetroot and its nanoformulation strategies for phytocompounds on antimicrobial, antiviral effects, etc. Moreover, epigenetic alterations caused by phytocompounds of beetroot under several diseases were not reported much. Thus, extensive research must be carried out to understand the molecular effects of beetroot in the near future.

Integrating Transcriptomics and Free Fatty Acid Profiling Analysis Reveal Cu Induces Shortened Lifespan and Increased Fat Accumulation and Oxidative Damage in C. elegans

Nowadays, human beings are exposed to Cu in varieties of environmental mediums, resulting in health risks needing urgent attention. Our research found that Cu shortened lifespan and induced aging-related phenotypes of Caenorhabditis elegans (C. elegans). Transcriptomics data showed differential expression genes induced by Cu were mainly involved in regulation of metabolism and longevity, especially in fatty acid metabolism. Quantitative detection of free fatty acid by GC/MS further found that Cu upregulated free fatty acids of C. elegans. A mechanism study confirmed that Cu promoted the fat accumulation in nematodes, which was owing to disorder of fatty acid desaturase and CoA synthetase, endoplasmic reticulum unfolded protein response (UPR^ER), mitochondrial membrane potential, and unfolded protein response (UPR^mt). In addition, Cu activated oxidative stress and prevented DAF-16 translocating into nuclear with a concomitant reduction in the expression of environmental stress-related genes. Taken together, the research suggested that Cu promoted aging and induced fat deposition and oxidative damage.

Prospects and potentials of underutilized leafy Amaranths as vegetable use for health-promotion

Climate change causes environmental variation worldwide, which is one of the most serious threats to global food security. In addition, more than 2 billion people in the world are reported to suffer from serious malnutrition, referred to as 'hidden hunger.' Dependence on only a few crops could lead to the loss of genetic diversity and high fragility of crop breeding in systems adapting to global scale climate change. The exploitation of underutilized species and genetic resources, referred to as orphan crops, could be a useful approach for resolving the issue of adaptability to environmental alteration, biodiversity preservation, and improvement of nutrient quality and quantity to ensure food security. Moreover, the use of these alternative crops will help to increase the human health benefits and the income of farmers in developing countries. In this review, we highlight the potential of orphan crops, especially amaranths, for use as vegetables and health-promoting nutritional components. This review highlights promising diversified sources of amaranth germplasms, their tolerance to abiotic stresses, and their nutritional, phytochemical, and antioxidant values for vegetable purposes. Betalains (betacyanins and betaxanthins), unique antioxidant components in amaranth vegetables, are also highlighted regarding their chemodiversity across amaranth germplasms and their stability and degradation. In addition, we discuss the physiological functions, antioxidant, antilipidemic, anticancer, and antimicrobial activities, as well as the biosynthesis pathway, molecular, biochemical, genetics, and genomic mechanisms of betalains in detail.

Garambullo (Myrtillocactus geometrizans): effect of in vitro gastrointestinal digestion on the bioaccessibility and antioxidant capacity of phytochemicals

Garambullo (Myrtillocactus geometrizans), endemic fruit from Mexico, contains several bioactive compounds (phenolic compounds, betalains, antioxidant fiber), highlighting it as a good functional food. In this research, the impact of the in vitro gastrointestinal digestion on phytochemical bioaccessibility from garambullo and its antioxidant capacity are studied. The fruit contained previously unidentified phytochemicals in the polar and non-polar extracts (acetone and hexane). The bioaccessibility decreased in the mouth and stomach for flavanones (up to 11.9 and 8.9%, respectively), isoflavones (up to 20.0 and 9.2%, respectively), flavonols (up to 15.2 and 15.7%, respectively), hydroxycinnamic acids (up to 21.7 and 13.1%, respectively), and betalains (up to 10.5 and 4.2%, respectively); hydroxybenzoic acids were increased (up to 752.8 and 552.6%, respectively), while tocopherols increased in the mouth (127.7%) and decreased in the stomach (up to 90.3%). In the intestinal phase, the digestible fraction showed low phytochemicals bioaccessibility, and some compounds were recovered in the non-digestible fraction. The antioxidant capacity decreased in different compartments of the gastrointestinal tract, being higher in the mouth (872.9, 883.6, 385.2, and 631.2 μmol TE per g dw by ABTS, DPPH, ORAC, and FRAP, respectively) and stomach (836.2, 942.1, 289.0, and 494.9 μmol TE per g dw ABTS, DPPH, ORAC, and FRAP, respectively). The results indicate that digestion positively or negatively affects compounds' bioaccessibility depending on their structural family, and the antioxidant capacity decreases but remains higher than other functional foods.

Lentinan extends lifespan and increases oxidative stress resistance through DAF-16 and SKN-1 pathways in Caenorhabditis elegans

Lentinan, extracted from Lentinus edodes, exhibits bioactive properties in vitro; however, little is known about the antioxidant potential in vivo. In this study, the effects of lentinan at 0.05, 0.25 and 1.25 mg/mL on the lifespan, locomotion, reproductive capacity, and oxidative stress resistance in Caenorhabditis elegans were determined. Compared to the untreated control, lentinan at 0.05, 0.25 and 1.25 mg/mL significantly prolonged the lifespan by 17.6%, 35.3% and 25.3% (p < 0.001), respectively, and improved the brood size, locomotion and stress resistance of the nematodes. Furthermore, lentinan at 0.25 mg/mL significantly reduced accumulation of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) by 38.1% (p = 0.013) and 49.7% (p = 0.028), respectively. In addition, lentinan at all tested concentrations significantly increased the activities of superoxide dismutase (SOD) and catalase (CAT). The expression of skn-1 and daf-16 in the treatments with lentinan at 0.25 and 1.25 mg/mL was significantly (p < 0.005) up-regulated compared with the untreated control, whereas that of the daf-2 gene was significantly down-regulated. Further evidence revealed that ROS production in lentinan-treated daf-16 and skn-1 mutant strains was similar to the untreated control. Consistent with the aforementioned results, lentinan enhanced the nuclear translocation of DAF-16 and SKN-1. Our results demonstrated that lentinan could increase lifespan and protect the nematodes from oxidative stress through DAF-16 and SKN-1.

Current Understanding of Modes of Action of Multicomponent Bioactive Phytochemicals: Potential for Nutraceuticals and Antimicrobials

Plants produce a diversity of plant secondary metabolites (PSMs), which function as defense chemicals against herbivores and microorganisms but also as signal compounds. An individual plant produces and accumulates mixtures of PSMs with different structural features using different biosynthetic pathways. Almost all PSMs exert one or several biological activities that can be useful for nutrition and health. This review discusses the modes of action of PSMs alone and in combinations. In a mixture, most individual PSMs can modulate different molecular targets; they are thus multitarget drugs. In an extract with many multitarget chemicals, additive and synergistic effects occur. Experiments with the model system Caenorhabditis elegans show that polyphenols and carotenoids can function as powerful antioxidative and longevity-promoting PSMs. PSMs of food plants and spices often exhibit antioxidant, anti-inflammatory, and antimicrobial properties, which can be beneficial for health and the prevention of diseases. Some extracts from food plants and spices with bioactive PSMs have potential for nutraceuticals and antimicrobials.

Mixed solid-state fermentation for releasing bound polyphenols from insoluble dietary fiber in carrots via Trichoderma viride and Aspergillus niger

This study aimed to explore the release mechanism of bound polyphenols (BP) from the insoluble dietary fiber (IDF) in carrots via mixed solid-state fermentation (MSF) using Trichoderma viride and Aspergillus niger. The results indicated that BP released by MSF (80.8759 mg GAE per 10 g DW) was significantly higher than that by alkaline hydrolysis. In addition, 17 polyphenols were detected and their biotransformation pathways were proposed. Quantitative analysis showed that MSF released numerous p-coumaric and organic acids, which led to both an enhancement in α-amylase inhibitory activity and elevated antioxidant enzyme activity in Caenorhabditis elegans (C. elegans). Furthermore, the dynamic changes in the carbohydrate-hydrolyzing enzymes and the structural characteristics indicated that the destruction of hemicellulose, the deposition of lignin and the secretion of xylanase were vital for the release of BP. Overall, this study demonstrated that MSF is beneficial for the release of BP from IDF, which could provide new insight into the utilization of agricultural byproducts in a more natural and economical way.

A pharmacognostic approach for mitigating pancreatic cancer: emphasis on herbal extracts and phytoconstituents

Background

Pancreatic cancer is studied as one of the most lethal cancers with currently no control of its lethality, mainly due to its late diagnosis and lack of foolproof treatment processes. Despite continuous efforts being made in looking for therapies to deal with cancer, it keeps on being a labyrinth for the researchers. Efforts like discovering new treatment options, repurposing existing drugs, are continuously made to deal with this cancer.

Main body

With the urge to get answers and the fact that nature has all roots of therapeutics, efforts are made in the direction of finding those answers for providing ministrations for pancreatic cancer from plant products. Plant products are used as treatment options either directly in the form of extracts or an alternative to them is individual phytochemicals that are either isolated from the plants or are commercially synthesized for various purposes. In this review, we put forward such pharmacognostic initiatives made in combating pancreatic cancer, focusing mainly on plant extracts and various phytochemicals; along with the mechanisms which they triggered to fulfill the need for cytotoxicity to pancreatic cancer cells (in vitro and in vivo).

Conclusion

This study will thus provide insights into new combination therapy that can be used and also give a clue on which plant product and phytoconstituent can be used in dealing with pancreatic cancer.

Graphical abstract

The lipid lowering and antioxidative stress potential of polysaccharide from Auricularia auricula prepared by enzymatic method

An efficient extraction method of Auricularia auricula polysaccharides (AAPs) by neutral protease was developed and optimized by response surface methodology. AAPs were graded by stepwise ethanol precipitation, the fraction with high recovery rate and strong radical scavenging rate were obtained, then its antioxidant and lipid lowering effect were studied using Caenorhabditis elegans as model organism. The extract yield and ABTS⁺ scavenging rates of AAPs could reach 14.90% and 86.0% at 50 °C, 75 mL/g of liquid-to-material ratio and pH 9.0. AAP3 obtained by 15% ethanol was a heteropolysaccharide comprised of mannose, glucose, glucuronic acid, xylose, galactose and glucosamine. AAP3 could significantly prolong the lifespan of C. elegans and enhance the activity of antioxidant enzymes including superoxide dismutase (SOD), catalases (CAT) at 0.25 mg/mL (p < 0.05). The qRT-PCR results showed that AAP3 could up regulate mRNA expression levels of daf-16 and skn-1 (>1.6 fold) at 0.25 mg/mL. Besides, AAP3 could significantly reduce the level of body fat and triglyceride in C. elegans (p < 0.05). These studies demonstrated that A. auricula polysaccharides prepared by neutral protease had a prominent protective effect to the damage induced by the intracellular free radical generating agents.

Biological Properties and Applications of Betalains

Betalains are water-soluble pigments present in vacuoles of plants of the order Caryophyllales and in mushrooms of the genera Amanita, Hygrocybe and Hygrophorus. Betalamic acid is a constituent of all betalains. The type of betalamic acid substituent determines the class of betalains. The betacyanins (reddish to violet) contain a cyclo-3,4-dihydroxyphenylalanine (cyclo-DOPA) residue while the betaxanthins (yellow to orange) contain different amino acid or amine residues. The most common betacyanin is betanin (Beetroot Red), present in red beets Beta vulgaris, which is a glucoside of betanidin. The structure of this comprehensive review is as follows: Occurrence of Betalains; Structure of Betalains; Spectroscopic and Fluorescent Properties; Stability; Antioxidant Activity; Bioavailability, Health Benefits; Betalains as Food Colorants; Food Safety of Betalains; Other Applications of Betalains; and Environmental Role and Fate of Betalains.

Flavonoids' Effects on Caenorhabditis elegans' Longevity, Fat Accumulation, Stress Resistance and Gene Modulation Involve mTOR, SKN-1 and DAF-16

Flavonoids are potential nutraceutical compounds present in diary food. They are considered health-promoting compounds and promising drugs for different diseases, such as neurological and inflammatory diseases, diabetes and cancer. Therefore, toxicological and mechanistic studies should be done to assert the biological effects and identify the molecular targets of these compounds. In this work we describe the effects of six structurally-related flavonoids—baicalein, chrysin, scutellarein, 6-hydroxyflavone, 6,7-dihydroxyflavone and 7,8-dihydroxyflavone—on Caenorhabditis elegans’ lifespan and stress resistance. The results showed that chrysin, 6-hydroxyflavone and baicalein prolonged C. elegans’ lifespan by up to 8.5%, 11.8% and 18.6%, respectively. The lifespan extensions caused by these flavonoids are dependent on different signaling pathways. The results suggested that chrysin’s effects are dependent on the insulin signaling pathway via DAF-16/FOXO. Baicalein and 6-hydroxyflavone’s effects are dependent on the SKN-1/Nfr2 pathway. In addition, microarray analysis showed that baicalein downregulates important age-related genes, such as mTOR and PARP.

Biosynthesis of a novel polymeric chitosan-betaxanthin and characterization of the first sugar-derived betalains and their effects in the in vivo model Caenorhabditis elegans

Betaxanthins are nitrogenous plant pigments belonging to the family of betalains and they are known for their health-promoting effects and fluorescent properties. A novel biotechnological approach in the synthesis of these compounds has allowed the synthesis of high amounts of known betalains and of novel, tailor-made betalains through the condensation of the structural unit - betalamic acid - with amine groups of different compounds. Here we describe the synthesis and characterization of chitosan-betaxanthin, the first fluorescent polymeric betaxanthin which forms nanoparticles and that might combine the fluorescent properties of betalains and the properties of chitosan, a sugar polymer widely used with medical purposes. In addition, glucosamine, the structural unit of chitosan, and its stereoisomer galactosamine were shown to condense in solution with betalamic acid. This produced novel molecules with spectral and in vivo antioxidant and anti-aging properties similar to those of biological betaxanthins, which are the first sugar-derived betaxanthins described.

Attenuation of Nrf2/Keap1/ARE in Alzheimer's Disease by Plant Secondary Metabolites: A Mechanistic Review

Alzheimer’s disease (AD) is a progressive neuronal/cognitional dysfunction, leading to disability and death. Despite advances in revealing the pathophysiological mechanisms behind AD, no effective treatment has yet been provided. It urges the need for finding novel multi-target agents in combating the complex dysregulated mechanisms in AD. Amongst the dysregulated pathophysiological pathways in AD, oxidative stress seems to play a critical role in the pathogenesis progression of AD, with a dominant role of nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein-1 (Keap1)/antioxidant responsive elements (ARE) pathway. In the present study, a comprehensive review was conducted using the existing electronic databases, including PubMed, Medline, Web of Science, and Scopus, as well as related articles in the field. Nrf2/Keap1/ARE has shown to be the upstream orchestrate of oxidative pathways, which also ameliorates various inflammatory and apoptotic pathways. So, developing multi-target agents with higher efficacy and lower side effects could pave the road in the prevention/management of AD. The plant kingdom is now a great source of natural secondary metabolites in targeting Nrf2/Keap1/ARE. Among natural entities, phenolic compounds, alkaloids, terpene/terpenoids, carotenoids, sulfur-compounds, as well as some other miscellaneous plant-derived compounds have shown promising future accordingly. Prevailing evidence has shown that activating Nrf2/ARE and downstream antioxidant enzymes, as well as inhibiting Keap1 could play hopeful roles in overcoming AD. The current review highlights the neuroprotective effects of plant secondary metabolites through targeting Nrf2/Keap1/ARE and downstream interconnected mediators in combating AD.

Antitumoral Drug Potential of Tryptophan-Betaxanthin and Related Plant Betalains in the Caenorhabditis elegans Tumoral Model

Betalains are plants pigments identified as potent antioxidant molecules, naturally present in foods like beetroot and prickly pears. Although activities described for betalain-containing formulations include cancer prevention and treatment, the use of extracts instead of purified pigments has avoided the investigation of the real chemopreventive and chemotherapeutic potential of these phytochemicals. Three betalain-rich extracts and six individual pure betalains were used in this work to characterize the activity and to explore possible molecular mechanisms. The animal model Caenorhabditis elegans (tumoral strain JK1466) was used to evaluate the effect of betalains as chemotherapeutics drugs. An objective evaluation method of tumor growth in C. elegans has been developed to assess the possible antitumoral activity of the different treatments. This protocol allowed a fast and reliable screening of possible antitumoral drugs. Among the betalains tested, tryptophan-betaxanthin reduced tumor size by 56.4% and prolonged the animal’s lifespan by 9.3%, indicating high effectiveness and low toxicity. Structure–activity relationships are considered. Assays with mutant strains of C. elegans showed that the mechanism underlying these effects was the modulation of the DAF-16 transcription factor and the insulin signaling pathway. Our results indicate that tryptophan-betaxanthin and related betalains are strong candidates as antitumoral molecules in cancer treatment.