Antioxidant and immunoregulatory activity of polysaccharides from quinoa (Chenopodium quinoa Willd.)

Cereal polyphenols inhibition mechanisms on advanced glycation end products and regulation on type 2 diabetes

Advanced glycation end products (AGEs), the products of non-enzymatic browning reactions between the active carbonyl groups of reducing sugars and the free amines of amino acids, are largely considered oxidative derivatives resulting from diabetic hyperglycemia, which are further recognized as a potential risk for insulin resistance (IR) and type 2 diabetes (T2D). The accumulation of AGEs can trigger numerous negative effects such as oxidative stress, carbonyl stress, inflammation, autophagy dysfunction and imbalance of gut microbiota. Recently, studies have shown that cereal polyphenols have the ability to inhibit the formation of AGEs, thereby preventing and alleviating T2D. In the meanwhile, phenolics compounds could produce different biological effects due to the quantitative structure activity-relationship. This review highlights the effects of cereal polyphenols as a nonpharmacologic intervention in anti-AGEs and alleviating T2D based on the effects of oxidative stress, carbonyl stress, inflammation, autophagy, and gut microbiota, which also provides a new perspective on the etiology and treatment of diabetes.

Harnessing the Potential of Quinoa: Nutritional Profiling, Bioactive Components, and Implications for Health Promotion

Quinoa, a globally cultivated "golden grain" belonging to Chenopodium in the Amaranthaceae family, is recognized for being gluten-free, with a balanced amino acid profile and multiple bioactive components, including peptides, polysaccharides, polyphenols, and saponins. The bioactive compounds extracted from quinoa offer multifaceted health benefits, including antioxidative, anti-inflammatory, antimicrobial, cardiovascular disease (CVD) improvement, gut microbiota regulation, and anti-cancer effects. This review aims to intricately outline quinoa's nutritional value, functional components, and physiological benefits. Importantly, we comprehensively provide conclusions on the effects and mechanisms of these quinoa-derived bioactive components on multiple cancer types, revealing the potential of quinoa seeds as promising and effective anti-cancer agents. Furthermore, the health-promoting role of quinoa in modulating gut microbiota, maintaining gut homeostasis, and protecting intestinal integrity was specifically emphasized. Finally, we provided a forward-looking description of the opportunities and challenges for the future exploration of quinoa. However, in-depth studies of molecular targets and clinical trials are warranted to fully understand the bioavailability and therapeutic application of quinoa-derived compounds, especially in cancer treatment and gut microbiota regulation. This review sheds light on the prospect of developing dietary quinoa into functional foods or drugs to prevent and manage human diseases.

Comparison of soluble dietary fibers from various quinoa microgreens: Structural characteristics and bioactive properties

Quinoa (Chenopodium quinoa Willd.) microgreens are widely consumed as healthy vegetables around the world. Although soluble dietary fibers exist as the major bioactive macromolecules in quinoa microgreens, their structural characteristics and bioactive properties are still unclear. Therefore, the structural characteristics and bioactive properties of soluble dietary fibers from various quinoa microgreens (QMSDFs) were investigated in this study. The yields of QMSDFs ranged from 38.82 to 52.31 mg/g. Indeed, all QMSDFs were predominantly consisted of complex pectic-polysaccharides, e.g., homogalacturonan (HG) and rhamnogalacturonan I (RG I) pectic domains, with the molecular weights ranged from 2.405 × 104 to 5.538 × 104 Da. In addition, the proportions between RG I and HG pectic domains in all QMSDFs were estimated in the range of 1: 2.34-1: 4.73 (ratio of galacturonic acid/rhamnose). Furthermore, all QMSDFs exhibited marked in vitro antioxidant, antiglycation, prebiotic, and immunoregulatory effects, which may be partially correlated to their low molecular weights and low esterification degrees. These findings are helpful for revealing the structural and biological properties of QMSDFs, which can offer some new insights into further development of quinoa microgreens and related QMSDFs as value-added healthy products.

Genome-wide identification, characterization and expression analysis of AGO, DCL, and RDR families in Chenopodium quinoa

RNA interference is a highly conserved mechanism wherein several types of non-coding small RNAs regulate gene expression at the transcriptional or post-transcriptional level, modulating plant growth, development, antiviral defence, and stress responses. Argonaute (AGO), DCL (Dicer-like), and RNA-dependent RNA polymerase (RDR) are key proteins in this process. Here, these three protein families were identified in Chenopodium quinoa. Further, their phylogenetic relationships with Arabidopsis, their domains, three-dimensional structure modelling, subcellular localization, and functional annotation and expression were analysed. Whole-genome sequence analysis predicted 21 CqAGO, eight CqDCL, and 11 CqRDR genes in quinoa. All three protein families clustered into phylogenetic clades corresponding to those of Arabidopsis, including three AGO clades, four DCL clades, and four RDR clades, suggesting evolutionary conservation. Domain and protein structure analyses of the three gene families showed almost complete homogeneity among members of the same group. Gene ontology annotation revealed that the predicted gene families might be directly involved in RNAi and other important pathways. Largely, these gene families showed significant tissue-specific expression patterns, RNA-sequencing (RNA-seq) data revealed that 20 CqAGO, seven CqDCL, and ten CqRDR genes tended to have preferential expression in inflorescences. Most of them being downregulated in response to drought, cold, salt and low phosphate stress. To our knowledge, this is the first study to elucidate these key protein families involved in the RNAi pathway in quinoa, which are significant for understanding the mechanisms underlying stress responses in this plant.

Effects of Quinoa (Chenopodium quinoa) on inflammatory mediators: a systematic review of preclinical studies

The aim of the current systematic review was to gather the researches about the effect of quinoa (chenopodium quinoa) on inflammatory parameters interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α). Search was performed using PubMed, Scopus, WOS, ProQuest, and Google scholar databases without any restriction on language or publication date until July 2022 and search alert services were used to detect novel papers published after the initial search. Only 20 animal and in vitro investigations were eligible for this systematic review. According to in vitro researches and 8 of 14 animal investigations, IL-6, IL-1β, and TNF-α level decreased remarkably after quinoa administration, which indicates the capability of quinoa in alleviating inflammatory factors. Quinoa is favorable but not yet a confirmed agent for alleviating systemic inflammation in inflammatory diseases.

Effect of soy protein isolate on physical properties of quinoa dough and gluten-free bread quality characteristics

BACKGROUND

Quinoa is a good gluten-free resource for food processing, especially bread making, and can improve and prevent the development of complications associated with celiac disease (CD). However, lack of gluten affects quinoa bread quality. Previous research showed that soy protein isolate (SPI) could improve gluten-free bread quality to some extent. Therefore, this study investigated the effects of SPI on the physical properties of quinoa dough and gluten-free bread quality characteristics.

RESULTS

Results showed that, with appropriate SPI substitution, the farinograph properties of quinoa flour significantly improved (P < 0.05). The sample with 8% SPI substitution showed a better development time (DT, 3.30 ± 0.20 min), stability time (ST, 8.80 ± 0.10 min) and softening degree (SD, 8.80 ± 0.10 FU), which were close to those of wheat flour, although more water absorption (WA, 76.40 ± 2.10%) was needed than for wheat flour (66.30 ± 3.10%). The extensograph properties of quinoa flour also significantly improved after 8% SPI substitution (P < 0.05). Furthermore, SPI substitution increased G' moduli of quinoa dough and decreased tan δ to some extent, providing better rheological properties closer to those of wheat dough. SPI substitution also improved the quality and texture of quinoa bread and reduced the gap with wheat bread. When SPI substitution was 8%, the specific volume, hardness and springiness of quinoa bread were 2.29 ± 0.05 mL g^-1 , 1496.47 ± 85.21 g and 0.71 ± 0.03%, respectively.

CONCLUSION

These results suggested that SPI substitution would be an effective way to develop higher-quality gluten-free bread. © 2022 Society of Chemical Industry.

Medicinal Plants in Peru as a Source of Immunomodulatory Drugs Potentially Useful Against COVID-19

The current COVID-19 pandemic, characterized by a highly contagious severe acute respiratory syndrome, led us to look for medicinal plants as an alternative to obtain new drugs, especially those with immunomodulatory abilities, capable of acting against the pulmonary infection caused by coronavirus 2 (SARS-CoV-2). Despite medical advances with COVID-19 drugs and vaccines, plant-based compounds could provide an array of suitable candidates to test against this virus, or at the very least, to alleviate some symptoms. Therefore, this review explores some plants widely used in Peru that show immunomodulatory properties or, even more, contain phytoconstituents potentially useful to prevent or alleviate the COVID-19 infection. More interestingly, the present review highlights relevant information from those plants to support the development of new drugs to boost the immune system. We used three criteria to choose nine vegetal species, and a descriptive search was then conducted from 1978 to 2021 on different databases, using keywords focused on the immune system that included information such as pharmacological properties, phytochemical, botanical, ethnobotanical uses, and some clinical trials. From these literature data, our results displayed considerable immunomodulation activity along with anti-inflammatory, antiviral, antioxidant, and antitumoral activities. Noticeably, these pharmacological activities are related with a wide variety of bioactive phytoconstituents (mixtures or isolated compounds) which may be beneficial in modulating the overt inflammatory response in severe COVID-19. Further scientific research on the pharmacological activities and clinical utilization of these potential plants are warranted.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s43450-023-00367-w.

Physicochemical characteristics and biological activities of soluble dietary fibers isolated from the leaves of different quinoa cultivars

Quinoa leaf is consumed as a promising value-added vegetable in the diet. Although quinoa leaf is rich in soluble dietary fibers, the knowledge regarding their chemical structures and biological activities is still limited, which astricts their application in the functional food industry. Thus, to improve the precise use and application of soluble dietary fibers (SDFs) isolated from quinoa leaves in the food industry, the physicochemical structures and bioactivities of SDFs isolated from different quinoa leaves were systematically investigated. Results indicated that quinoa leaves were rich in SDFs, ranging from 3.30 % to 4.55 % (w/w). Quinoa SDFs were mainly composed of acidic polysaccharides, such as homogalacturonan and rhamnogalacturonan I, which had the molecular weights in the range of 4.228 × 10⁴ -7.059 × 10⁴ Da. Besides, quinoa SDFs exerted potential in vitro antioxidant activities, lipid and bile acid-adsorption capacities, immunoregulatory activities, and prebiotic effects, which might be partially associated with their molecular mass, content of uronic acid, and content of bound polyphenol. Collectively, these findings are beneficial to better understanding the chemical structures and bioactivities of SDFs extracted from different quinoa leaves, which can also provide a scientific basis for developing quinoa SDFs into functional foods in the food industry.

Total saponins from quinoa bran alleviate high-fat diet-induced obesity and systemic inflammation via regulation of gut microbiota in rats

In recent years, biologically active ingredients derived from natural plants or functional foods have raised considerable interests for its anti-obesity effect. Quinoa (Chenopodium quinoa Willd.) is a traditional staple food in the Andean regions of Peru which contains a variety of bioactive components. This study aimed to investigate the potential therapeutic effect of total saponins extracted from quinoa bran (TSQ) on obese rats and explore whether the underlying mechanism is related to intestinal microbiota. Results showed that TSQ could decrease the body weight gain and visceral fat accumulation in the obese rats. Moreover, trends in ameliorating insulin resistance and improved glucose tolerance were observed. Indeed, Pearson's correlations analysis revealed that the variation in gut microbial composition was highly correlated to insulin resistance, IL-6, and LPS levels. Collectively, these results suggest that the prevention of obesity and inflammation by TSQ may be mediated by the modulation of gut microbial composition.

Structural characterization and bioactivity evaluation of water-extractable polysaccharides from chickpeas (Cicer arietinum L.) seeds

Two water-extractable polysaccharide fractions designated as CWP (7. 37 × 105 Da) and CWP-0.2 (1.58 × 104 Da) were isolated and purified from chickpea (Cicer arietinum L.) seeds. The chemical structure of the two polysaccharides was characterized by various methods. Monosaccharide composition and methylation analysis showed that CWP was composed of Man and Glc in a molar ratio of 44.6:55.4, and CWP-0.2 was composed of Rha, Ara, Man, Glc, and Gal in a molar ratio of 10.6:23.3:5.2:4.9:56. Further structural characterization indicated that the main chain connection of CWP was → (2-β-d-Fruf-1) n →, and the main chain connection of CWP-0.2 was explored as → 2,4)-α-l-Rhap-(1 → 3)-α-d-Galp-(1 → with the branched chain of → 2,4)-α-l-Rhap-(1 → o-4. Besides, both CWP and CWP-0.2 had antioxidant and immunoregulatory activity in vitro, through scavenging DPPH· and ABTS·+ as well as stimulating production of NO, IL-6, TNF-α and MCP-1 in RAW 264.7 macrophages. CWP-0.2 revealed significantly higher bioactivity than CWP.

Nutrient composition of Chenopodium formosanum Koidz. bran: Fractionation and bioactivity of its soluble active polysaccharides

Background

Chenopodium formosanum Koidz. Amaranthaceae-also known as Djulis or red quinoa (RQ)-is a cereal plant indigenous to Taiwan, known for its high nutrient value. However, its bran is considered a waste product and the nutrient value has never been analyzed.

Methods

In this study, we examined the proximate composition of RQ bran, specifically its soluble polysaccharide fractions.

Results

RQ bran exhibited high contents of protein (16.56%), ash (7.10%), carbohydrate (60.45%), total polyphenolics (1.85%), betaxanthin (9.91 mg/100 g of RQ bran), and indicaxanthin (7.27 mg/100 g of RQ bran). Specifically, it was rich in polyunsaturated fatty acids (PUFAs; 39.24%)-with an n-6/n-3 and PUFA/saturated fatty acid (SFA) ratio of 18.137 and 0.743, respectively. Four soluble polysaccharide fractions were also obtained: CF-1, CF-2, CF-3, and CF-4, with yields of 3.90%, 6.74%, 22.28%, and 0.06%, respectively, and molecular weights of 32.54, 24.93, 72.39, and 55.45 kDa, respectively. CF-1, CF-2, CF-3, and CF-4 had respectively 15.67%, 42.41%, 5.44%, and 14.52% peptide moiety content and 38.92%, 50.70%, 93.76%, and 19.80% carbohydrate moiety. In CF-2, the glucose content was 95.86 mol% and that of leucine was 16.23%, implicating the presence of a typical leucinoglucan. All four polysaccharide fractions lacked glutamic acid and hydroxyproline. The IC50 of CF-1, CF-2, and CF-3 was respectively 12.05, 3.98, and 14.5 mg/mL for DPPH free radical-scavenging ability; 5.77, 4.10, and 7.03 mg/mL for hydrogen peroxide-scavenging capability; 0.26, 0.05, and 0.19 mg/mL for O₂ ^- free radical-scavenging capability; and 100.41, 28.12, and 29.73 mg/mL for Fe²⁺ chelation.

Conclusion

Our results indicated that RQ bran has a large amount of nutrient compounds, and a cost-efficient process for their extraction is needed. Their biomedical application as nutraceuticals also warrants further investigation.

Peruvian Andean grains: Nutritional, functional properties and industrial uses

The Andean geography induces favorable conditions for the growth of food plants of high nutritional and functional value. Among these plants are the Andean grains, which are recognized worldwide for their nutritional attributes. The objective of this article is to show the nutritional and functional properties, as well as industrial potential, of Andean grains. Quinoa, amaranth, canihua, and Andean corn are grains that contain bioactive compounds with antioxidant, antimicrobial, and anti-inflammatory activities that benefit the health of the consumer. Numerous in vitro and in vivo studies demonstrate their functional potential. These high-Andean crops could be used industrially to add value to other functional food products. These reports suggest the inclusion of these grains in the daily diets of people and the application of their active compounds in the food industry.

Alleviating the effect of quinoa and the underlying mechanism on hepatic steatosis in high-fat diet-fed rats

Background

Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic component of metabolic syndrome and has attracted widespread attention due to its increased prevalence. Daily dietary management is an effective strategy for the prevention of NAFLD. Quinoa, a nutritious pseudocereal, is abundant in antioxidative bioactive phytochemicals. In the present study, the effects of different amounts of quinoa on the progression of NAFLD and the related molecular mechanism were investigated.

Methods

Male SD rats were simultaneously administered a high fat diet (HF) and different amounts of quinoa (equivalent to 100 g/day and 300 g/day of human intake, respectively). After 12 weeks of the intervention, hepatic TG (triglyceride) and TC (total cholesterol) as well as serum antioxidative parameters were determined, and hematoxylin–eosin staining (H&E) staining was used to evaluate hepatic steatosis. Differential metabolites in serum and hepatic tissue were identified using UPLC-QTOF-MS^E. The mRNA expression profile was investigated using RNA-Seq and further verified using real-time polymerase chain reaction (RT-PCR).

Results

Low amounts of quinoa (equivalent to 100 g/d of human intake) effectively controlled the weight of rats fed a high-fat diet. In addition, quinoa effectively inhibited the increase in hepatic TG and TC levels, mitigated pathological injury, promoted the increase in SOD and GSH-Px activities, and decreased MDA levels. Nontarget metabolic profile analysis showed that quinoa regulated lipid metabolites in the circulation system and liver such as LysoPC and PC. RNA-Seq and RT-PCR verification revealed that a high amount of quinoa more effectively upregulated genes related to lipid metabolism [Apoa (apolipoprotein)5, Apoa4, Apoc2] and downregulated genes related to the immune response [lrf (interferon regulatory factor)5, Tlr6 (Toll-like receptor), Tlr10, Tlr11, Tlr12].

Conclusion

Quinoa effectively prevented NAFLD by controlling body weight, mitigating oxidative stress, and regulating the lipid metabolic profile and the expression of genes related to lipid metabolism and the immune response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00631-7.

Physicochemical properties, structural characterization and biological activities of polysaccharides from quinoa (Chenopodium quinoa Willd.) seeds

In this paper, membrane separation technology was employed to separate polysaccharide fractions from the water extract of quinoa seeds. The chemical composition, structure characteristic and morphology were analyzed by chemical methods and instrumental analysis including HPLC-DAD, UV, FT-IR, Congo red test, SEM, AFM, XRD, TGA and NMR. Results indicated that three polysaccharide fractions named as QPs-I, QPs-II and QPs-III were successfully separated using microfiltration and ultrafiltration membrane with MWCO of 300 and 10 kDa in sequence. The Mw and polysaccharide content of three fractions were QPs-I (4609 Da, 33.75%), QPs-II (15,932 Da, 45.31%) and QPs-III (960,895 Da, 34.65%), respectively. The polysaccharide in three fractions was heteropolysaccharide that mainly consisted of glucose, galactose and arabinose, with their combined monosaccharide percentage being 91.17% in QPs-I, 87.81% in QPs-II, and 91.72% in QPs-III, respectively. All three polysaccharide fractions contained triple-helix structure. Biological experiment showed that antioxidant and antidiabetic activities in dose-dependent manners and also revealed immunoregulatory activity on RAW264.7 cells. These results indicated that QPs has the potential to be used in a natural agent in antioxidant, antidiabetic and immunoregulation functional food.

In vitro study of the effect of quinoa and quinoa polysaccharides on human gut microbiota

It has been shown that whole grains and dietary fiber are important for their fermentation characteristics in the large intestine, drawing more and more attention to quinoa and quinoa polysaccharides. In this study, we evaluated the prebiotic effect of quinoa seeds and quinoa polysaccharides after human simulated digestion. The modulatory effect of the quinoa and quinoa polysaccharides (QPs) on the gut microbiota was evaluated by the in vitro fermentation using human fecal microbiota. The yield of polysaccharides extraction was 15.45%. The digestibility of the cooked and uncooked quinoa after simulation of human digestion was 69.04% and 64.09%, respectively. The effect on the microbiota composition and their metabolic products was determined by the assessment of pH, short-chain fatty acids (SCFAs), and changes in the bacterial population. After 24 hr anaerobic incubation, the total SCFAs of cooked, uncooked quinoa, and quinoa polysaccharides were 82.99, 77.11, and 82.73 mM, respectively with a pH decrease. At the phylum, genus, and class level, it has been found that the quinoa substrates enhance the growth of certain beneficial bacteria such as Prevotella and Bacteroides. Quinoa polysaccharides can be considered prebiotic due to their ability to increase Bifidobacterium and Collinsella. Principal component analysis (PCA) showed that there was a distinct modulating effect on the fecal microbiota which represents different distribution. Our research suggests that quinoa and quinoa polysaccharides have a prebiotic potential due to their association with the positive shifts in microbiota composition and short-chain fatty acids production, which highlights the importance of further studies around this topic.

Whole grain cereals: the potential roles of functional components in human health

Whole grain cereals have been the basis of human diet since ancient times. Due to rich in a variety of unique bioactive ingredients, they play an important role in human health. This review highlights the contents and distribution of primary functional components and their health effects in commonly consumed whole grain cereals, especially dietary fiber, protein, polyphenols, and alkaloids. In general, cereals exert positive effects in the following ways: 1) Restoring intestinal flora diversity and increasing intestinal short-chain fatty acids. 2) Regulating plasma glucose and lipid metabolism, thereby the improvement of obesity, cardiovascular and cerebrovascular diseases, diabetes, and other chronic metabolic diseases. 3) Exhibiting antioxidant activity by scavenging free radicals. 4) Preventing gastrointestinal cancer via the regulation of classical signaling pathways. In summary, this review provides a scientific basis for the formulation of whole-grain cereals-related dietary guidelines, and guides people to form scientific dietary habits, so as to promote the development and utilization of whole-grain cereals.

Medicinal Plants and Isolated Molecules Demonstrating Immunomodulation Activity as Potential Alternative Therapies for Viral Diseases Including COVID-19

Plants have been extensively studied since ancient times and numerous important chemical constituents with tremendous therapeutic potential are identified. Attacks of microorganisms including viruses and bacteria can be counteracted with an efficient immune system and therefore, stimulation of body's defense mechanism against infections has been proven to be an effective approach. Polysaccharides, terpenoids, flavonoids, alkaloids, glycosides, and lactones are the important phytochemicals, reported to be primarily responsible for immunomodulation activity of the plants. These phytochemicals may act as lead molecules for the development of safe and effective immunomodulators as potential remedies for the prevention and cure of viral diseases. Natural products are known to primarily modulate the immune system in nonspecific ways. A number of plant-based principles have been identified and isolated with potential immunomodulation activity which justify their use in traditional folklore medicine and can form the basis of further specified research. The aim of the current review is to describe and highlight the immunomodulation potential of certain plants along with their bioactive chemical constituents. Relevant literatures of recent years were searched from commonly employed scientific databases on the basis of their ethnopharmacological use. Most of the plants displaying considerable immunomodulation activity are summarized along with their possible mechanisms. These discussions shall hopefully elicit the attention of researchers and encourage further studies on these plant-based immunomodulation products as potential therapy for the management of infectious diseases, including viral ones such as COVID-19.

Enhanced antioxidant activity of Chenopodium formosanum Koidz. by lactic acid bacteria: Optimization of fermentation conditions

In this study, different probiotics commonly used to produce fermented dairy products were inoculated independently for Chenopodium formosanum Koidz. fermentation. The strain with the highest level of antioxidant activity was selected and the fermentation process was further optimized via response surface methodology (RSM). Lactobacillus plantarum BCRC 11697 was chosen because, compared to other lactic acid bacteria, it exhibits increased free radical scavenging ability and can produce more phenolic compounds, DPPH (from 72.6% to 93.2%), and ABTS (from 64.2% to 76.9%). Using RSM, we further optimize the fermentation protocol of BCRC 11697 by adjusting the initial fermentation pH, agitation speed, and temperature to reach the highest level of antioxidant activity (73.5% of DPPH and 93.8% of ABTS). The optimal protocol (pH 5.55, 104 rpm, and 24.4°C) resulted in a significant increase in the amount of phenolic compounds as well as the DPPH and ABTS free radical scavenging ability of BCRC 11697 products. The IC50 of the DPPH and ABTS free radical scavenging ability were 0.33 and 2.35 mg/mL, respectively, and both protease and tannase activity increased after RSM. An increase in lower molecular weight (<24 kDa) protein hydrolysates was also observed. Results indicated that djulis fermented by L. plantarum can be a powerful source of natural antioxidants for preventing free radical-initiated diseases.

Pectic polysaccharides from edible halophytes: Insight on extraction processes, structural characterizations and immunomodulatory potentials

The preparation, chemical properties and bio-activities of polysaccharides derived from halophytes have gained an increasing interest in the past few years. Phytochemical and pharmacological reports have shown that carbohydrates are important biologically active compounds of halophytes with numerous biological potentials. It is believed that the mechanisms involved in these bio-activities are due to the modulation of immune system. The main objective of this summary is to appraise available literature of a comparative study on the extraction, structural characterizations and biological potentials, particularly immunomodulatory effects, of carbohydrates isolated from halophytes (10 families). This review also attempts to discuss on bioactivities of polysaccharides related with their structure-activity relationship. Data indicated that the highest polysaccharides yield of around 35% was obtained under microwave irradiation. Structurally, results revealed that the most of extracted carbohydrates are pectic polysaccharides which mainly composed of arabinose (from 0.9 to 72%), accompanied by other monosaccharides (galactose, glucose, rhamnose, mannose and xylose), significant amounts of uronic acids (from 18.9 to 90.1%) and some proportions of fucose (from 0.2 to 8.3%). The molecular mass of these pectic polysaccharides was varied from 10 to 2650 kDa. Hence, the evaluation of these polysaccharides offers a great opportunity to discover novel therapeutic agents that presented especially beneficial immunomodulatory properties. Moreover, reports indicated that uronic acids, molecular weights, as well as the presence of sulfate and unmethylated acidic groups may play a significant role in biological activities of carbohydrates from halophyte species.

Rational design and synthesis of chitosan–quinoa polysaccharide composite aerogel and its adsorption properties for Congo red and methylene blue

This study was performed to investigate the potential application of a chitosan (CS) and quinoa polysaccharide (QS) composite aerogel for the adsorption of dyes from water.

Influence of Feeding Quinoa (Chenopodium quinoa) Seeds and Prickly Pear Fruit (Opuntia ficus indica) Peel on the Immune Response and Resistance to Aeromonas sobria Infection in Nile Tilapia (Oreochromis niloticus)

Simple Summary

The inclusion of dietary supplements as feed additives in fish feed promotes the growth, immunity, and health of the fish, thereby accomplishing extraordinary outcomes in the net gain of the farm. Therefore, the present study was conducted to evaluate the influence of using quinoa seeds (QU) and prickly pear fruit peel (PP) as dietary supplements for fish, at the dose levels of 10% and 20% of the diet, on the immune response and disease resistance against pathogens, providing a novel perspective in aquaculture. Our findings indicated that the inclusion of PP and QU into the diets of Nile tilapia (Oreochromis niloticus) as feed supplements improved the survival rate, as well as the hematological, digestive, antioxidant, and immunological parameters. Moreover, an improvement in the strength of Nile tilapia immune response against Aeromonas sobria (A. sobria) infection was observed, evidenced by the improvement in the survival rate of infected fish. This was accomplished through the protection of the hepatic tissue and modulation of the expression of immune-encoding genes, including the downregulation of the gene encoding TGF-β and upregulation of the IFN-γ-encoding gene. Moreover, histological restoration of the morphological structures of intestine, liver, and spleen tissues was observed, particularly at the supplementation level of 20%.

Abstract

In recent times, nutraceuticals have been used extensively to identify promising feed additives for the improvement of the aquaculture industry through the enhancement of growth and survival rates, potentiation of the immune responses, and fortification of the resistance against infectious bacterial diseases. In this study, Nile tilapia (Oreochromis niloticus) were fed with diets supplemented with quinoa seeds (QU) or prickly pear fruit peel (PP) at the dose levels of 10% or 20% of the diet. After 45 days of the feeding trial, the fish were exposed to Aeromonas sobria (A. sobria) challenge. The pre-challenge indices indicated that both supplements mediated a significant improvement in most of the estimated parameters, including survival rate, antioxidant status, hematological and immunological indices, and hepatoprotective potential. These effects were recorded in the groups fed with high doses of the supplements (20%). The least changes were observed in the QU₁₀-supplemented fish. In the spleen tissue, the TGF-β gene was upregulated in the PP₁₀-, PP₂₀- and QU₂₀-supplemented groups, while the expression of the IFN-γ gene remained unaffected in all the supplemented groups, except for the PP₂₀-supplemented group, which showed an upregulation. After the challenge with A. sobria, the relative survival percentage was improved by the supplementation of PP and QU, particularly in the PP₂₀-supplemented group, possibly via the promotion of immunological responses, hepatoprotective potency, and modulation of the studied genes. Moreover, the morphological structure of the tissues showed marked recovery. The findings suggest that Nile tilapia fed with different levels of PP peel and QU seeds, particularly at the level of 20%, enhanced the immune response in fish and improved their resistance against A. sobria infection.

Dietary quinoa (Chenopodium quinoa Willd.) polysaccharides ameliorate high-fat diet-induced hyperlipidemia and modulate gut microbiota

As the high nutritional and functional values of quinoa acknowledged, the increasing researches focus on the bioactivities and related mechanisms of its abundant carbohydrates. Herein, the beneficial effects of the soluble polysaccharide fraction from quinoa was investigated to lower the serum lipid of rats treated by high-fat diet (HFD) and call the disordered gut microbiota back. The polysaccharide faction was firstly extracted by ultrasonic-assisted extraction technology (yield of 9.65%) and characterized of the monosaccharide composition with glucose and arabinose (1.17:1, molar ratio). And then, the oral administration of quinoa polysaccharide of 300 mg·kg^-1·day^-1 and 600 mg·kg^-1·day^-1 for 8 weeks remarkably alleviated dyslipidemia by decreasing the levels of serum total triglyceride (TG), low density lipoprotein cholesterol (LDL-C), malondialdehyde (MDA), total glutamic pyruvic transaminase (ALT) and glutamic oxaloacetic transaminase (AST) in rats fed with HFD, as well as the reduced hepatic lipid accumulation. Meanwhile, the relative abundance of gut microbiota could be disordered by the long term of HFD. Nevertheless, dietary supplementation of quinoa polysaccharide could enhance species richness and regulate the gut microbiota community structure, reducing the ratio of Firmicutes and Bacteroides, the relative abundance of Proteobacteria. Meanwhile, Sequencing of 16S rRNA gene revealed that intake of quinoa polysaccharide decreased the relative abundances of Desulfovibrio and Allobaculum, which were positively correlated with serum lipid profiles and beneficial to lessen intestinal inflammation. Taken together, the present study demonstrated that quinoa polysaccharide supplementation could ameliorate the hyperlipidemia induced by HFD in association with modulating gut microbiota in a positive way.

Pseudocereal grains: Nutritional value, health benefits and current applications for the development of gluten-free foods

Nowadays, consumers are more conscious of the environmental and nutritional benefits of foods. Pseudocereals grains, edible seeds belonging to dicotyledonous plant species, are becoming a current trend in human diets as gluten-free (GF) grains with excellent nutritional and nutraceutical value. Pseudocereals are a good source of starch, fiber, proteins, minerals, vitamins, and phytochemicals such as saponins, polyphenols, phytosterols, phytosteroids, and betalains with potential health benefits. The present review aims to summarize the nutritional quality and phytochemical profile of the three main pseudocereal grains: quinoa, amaranth and buckwheat. In addition, current evidence about their health benefits in animal models and human studies is also provided in detail. Based on the accumulating research supporting the inclusion of pseudocereals grains in the diet of celiac persons, this review discusses the recent advances in their application for the development of new GF products. Future directions for a wider cultivation and commercial exploitation of these crops are also highlighted.

Quinoa Secondary Metabolites and Their Biological Activities or Functions

Quinoa (Chenopodium quinoa Willd.) was known as the "golden grain" by the native Andean people in South America, and has been a source of valuable food over thousands of years. It can produce a variety of secondary metabolites with broad spectra of bioactivities. At least 193 secondary metabolites from quinoa have been identified in the past 40 years. They mainly include phenolic acids, flavonoids, terpenoids, steroids, and nitrogen-containing compounds. These metabolites exhibit many physiological functions, such as insecticidal, molluscicidal and antimicrobial activities, as well as various kinds of biological activities such as antioxidant, cytotoxic, anti-diabetic and anti-inflammatory properties. This review focuses on our knowledge of the structures, biological activities and functions of quinoa secondary metabolites. Biosynthesis, development and utilization of the secondary metabolites especially from quinoa bran were prospected.

Chemical characterization, antioxidant, immune-regulating and anticancer activities of a novel bioactive polysaccharide from Chenopodium quinoa seeds

Chenopodium quinoa, a promising nutraceutical cereal, has attracted increasing research interest, yet its polysaccharides remains to get few systematic studies. In this study, we employed orthogonal experimental design to optimize the ultrasound-assisted extraction process for highest yield of C. quinoa polysaccharides. A novel C. quinoa polysaccharide (CQP) fraction with high content and low molecular weight (8852Da) was subsequently purified by column chromatography, constituted by galacturonic acid and glucose monosaccharides. The purified CQP exhibited significantly antioxidant effect against DPPH⁺ and ABTS⁺, with even higher efficiency than some other reported polysaccharides. Moreover, CQP could promote the RAW264.7 macrophage proliferation, while suppress the nitri oxide production on inflammatory RAW264.7 macrophage in a dose- and time-dependent manner. In view of the pathological correlation of free radical, inflammation and carcinogenesis, the anticancer effect of CQP was further investigated on human liver cancer SMMC 7721 and breast cancer MCF-7 cells. Interestingly, CQP displayed cytotoxicity against cancer cells, while none proliferation inhibition on normal cells. These results suggest that the bioactive polysaccharide from C. quinoa provided the promising potential as a natural antioxidant, immune-regulating and anticancer candidate for food and even drug application.

Mutation breeding of extracellular polysaccharide-producing microalga Crypthecodinium cohnii by a novel mutagenesis with atmospheric and room temperature plasma

Extracellular polysaccharides (EPS) produced by marine microalgae have the potential to be used as antioxidants, antiviral agents, immunomodulators, and anti-inflammatory agents. Although the marine microalga Crypthecodinium cohnii releases EPS during the process of docosahexaenoic acid (DHA) production, the yield of EPS remains relatively low. To improve the EPS production, a novel mutagenesis of C. cohnii was conducted by atmospheric and room temperature plasma (ARTP). Of the 12 mutants obtained, 10 mutants exhibited significantly enhanced EPS yield on biomass as compared with the wild type strain. Among them, mutant M7 was the best as it could produce an EPS volumetric yield of 1.02 g/L, EPS yield on biomass of 0.39 g/g and EPS yield on glucose of 94 mg/g, which were 33.85%, 85.35% and 57.17% higher than that of the wild type strain, respectively. Results of the present study indicated that mutagenesis of the marine microalga C. cohnii by ARTP was highly effective leading to the high-yield production of EPS.