Effects of extraction methods on the physicochemical characteristics and biological activities of polysaccharides from okra (Abelmoschus esculentus)

Antihyperglycemic activity of polyphenolic metabolites and biosynthesized silver nanoparticles from Pedalium murex: Characterization and application of antioxidant and uropathogenic antimicrobial activities

Pedalium murex commonly known as (large caltrops, bara gokhru) is a medicinal plant with potential therapeutic benefits. Hyperglycemia, a hallmark of diabetes, affects millions worldwide. Research on its leaf ethanol extract demonstrates potential for managing hyperglycemia in vitro and in vivo. Phytochemical analysis revealed secondary metabolites, including tannins, alkaloids, saponins, flavonoids, and polyphenols, with high levels of total flavonoids (287.5 ± 17.3 μg QEq./mg) and polyphenols (327.5 ± 17.2 μg QEq./mg). Scanning electron microscopy (SEM) confirmed the granular nature of synthesized silver nanoparticles (AgNPs) with a size range of 20-40 nm, while transmission electron microscopy (TEM) showed spherical AgNPs (20-50 nm). Energy-dispersive X-ray spectroscopy (EDX) identified silver (66.75 %), carbon (22.02 %), and oxygen (11.23 %) as the primary components. The extract effectively neutralized DPPH-free radicals (39.57 ± 4.77 %), while the AgNPs showed greater efficacy (68.23 ± 5.37 %). Superoxide radical (O2•-) reduction was significant for both the extract (59.33 ± 0.17 %) and AgNPs (38.73 ± 0.21 %), highlighting potent antioxidant properties. Hydroxyl radical (●OH) scavenging was higher for the extract (63.72 ± 0.17 %) than for AgNPs alone (36.71 ± 0.29 %). The AgNPs showed significant antimicrobial activity, with inhibition zones of 16.27 ± 0.18 mm against Staphylococcus aureus and 11.23 ± 0.17 mm against Candida albicans at 80 μg/mL. In toxicity studies, P. murex-AgNPs were well tolerated in mice. In hyperlipidemic mice, treatment with P. murex-AgNPs (350 mg/kg and 700 mg/kg) significantly reduced cholesterol, triglycerides, and LDL-c levels without affecting HDL-c. These findings provide valuable insights into the therapeutic potential of P. murex-AgNPs for the treatment of hyperlipidemia and diabetes.

Influence of one-step enzymatic modification on the structure, physicochemical, and functional properties of dietary fiber from corn husk rich in (hemi)cellulose

This study systematically evaluated enzymatic modification of corn husks rich in hemicellulose using different sources of cellulases for producing soluble dietary fiber (SDF) by comparing the differences in yields and characteristics of obtained polysaccharides, thereby developing a novel one-step enzymatic modification process without starch and protein removal pretreatment that was commonly used in traditional enzymatic modification processes. It was shown that Trichoderma reesei cellulases showed a better modification effect than Penicillium oxalicum cellulases, especially T. reesei SCB-18 cellulase, producing high-yield SDF with superior physicochemical and structural characteristics and functional properties such as high water-holding capacity and adsorption capacities for cholesterol and nitrite ion, good thermal stability, low crystallinity, and molecular weight through this one-step process. Increased porous structure and functional groups in the SDFs, which were caused by the degradation of cellulose and hemicelluloses in corn husk, should partially explain the improvement in physicochemical and functional properties. This study also evaluated the physicochemical and functional properties of insoluble dietary fiber (IDF) obtained by this process. It provides a simple and feasible enzymatic modification process to produce SDF and IDF from corn husks efficiently and at a low cost, thereby realizing the high-value application of corn husks.

Progress in the isolation, purification, structural characteristics and biological functions of polysaccharides from okra (Abelmoschus esculentus (L.) Moench): A review

Abelmoschus esculentus (L.) Moench (A. esculentus L.), commonly known as okra, is a famous tonic traditional Chinese medicine which have drawn significant interest because of its excellent edible and medicinal properties. A. esculentus L. polysaccharides (APs) are the main bioactive substances of A. esculentus L. In the past decades, various methods (e.g. triple-phase partitioning and -assisted extraction etc.) have shown promise in extraction, and diverse techniques (e.g. ethanol precipitation and chromatography etc) have already been in use in purification. Although techniques for the isolation and purification of APs are constantly evolving to better cope with their complex structural features, these techniques still need to be innovated. APs are heteropolysaccharides with complex structures, exhibiting various biological activities, such as antioxidant, anti-inflammatory and antidepressant effects. However, the structure-activity relationships (SARs) and mechanisms between their higher structures and pharmacological effects need to be further investigated. In view of this, this review provides a comprehensive overview of recent advances in APs extraction, purification, structural characterization and bioactivity, discusses structure-activity relationships, and outlines the current applications, challenges and prospect of APs. The aim of this review is to provide valuable insights and information to facilitate the use of APs in food and pharmaceutical applications.

Influences of physical field-assisted extraction on the chemical structures and In vitro fermentation properties of okra polysaccharides

In this study, microwave, ultrasonic, and combined ultrasonic-microwave were applied to extract polysaccharide from fermented okra extraction. The achieved polysaccharides were labeled OP-LM, OP-LU, and OP-LUM, respectively. The chemical structure and microbial fermentation characteristics of OP-LM, OP-LU, and OP-LUM were studied. The relationship between the chemical structure of three okra polysaccharides (OKPs) and the fermentation characteristics was also discussed. Results indicated that OP-LM, OP-LU, and OP-LUM could remarkably change the gut microbial composition, but they differ in physicochemical properties like molecular weight (Mw), monosaccharide content, apparent viscosity, and surface morphology, which lead to their different fermentation characteristics like bacterial density, sugar consumption rate, short-chain fatty acids (SCFAs) production, and gut microbial composition. Therefore, with the help of correlation analysis, it was found that the composition and type of monosaccharides, the length of the side chain, and the Mw could affect the modulation of OKPs on gut microbial composition. In addition, the length of the side chain also led to the change in SCFAs type and concentration. Overall, our findings contribute to revealing the potential relationship between chemical structures of OKPs and their gut microbial fermentation characteristics.

Simulated Gastrointestinal Digestion and In Vitro Fecal Fermentation of Purified Pyracantha fortuneana (Maxim.) Li Fruit Pectin

Pyracantha fortuneana, an underutilized wild plant, has been found to have a high nutritional value. This study used simulated digestion and fecal fermentation models to investigate the digestive properties of the purified acidic pectin polysaccharide of Pyracantha fortuneana and its impact on the gut microbiota and metabolites. Pyracantha fortuneana polysaccharide (PFP) is mainly composed of rhamnose (Rha), galacturonic acid (GalA), glucose (Glc), galactose (Gal), and arabinose (Ara), with a molecular weight (Mw) of 851.25 kDa. Following simulated digestion, the Mw of PFP remained consistent. The reduced sugar content showed minimal change, suggesting that PFP exhibits resistance to gastrointestinal digestion and can effectively reach the colon. Following fecal fermentation, the molecular weight, monosaccharide, and carbohydrate contents of PFP decreased, while the short-chain fatty acid content increased. This suggests that PFP is susceptible to degradation by microorganisms and can be metabolized into acetic acid and n-butyric acid, contributing to the regulation of intestinal health. Meanwhile, PFP promotes the reproduction of beneficial bacteria such as Bacteroides, Dialister, and Dysgonomonas, inhibits the growth of harmful bacteria like Proteus, and generates metabolites such as thiamine, leonuriside A, oxoadipic acid, S-hydroxymethylglutathione, and isonicotinic acid, which exert beneficial effects on human health. These results indicate that PFP has great potential in regulating the gut microbiota and generating beneficial metabolites to promote intestinal functional health and can be used as a prebiotic to prevent diseases by improving intestinal health.

Polysaccharides from Ganoderma lucidum attenuate cognitive impairment in 5xFAD mice by inhibiting oxidative stress and modulating mitochondrial dynamics via the Nrf2/antioxidative axis activation

Oxidative stress and mitochondrial dynamics imbalance are key contributors to AD pathogenesis. GLPS, an extract from Ganoderma lucidum spores, exhibits anti-inflammatory, antioxidant, and immunomodulatory properties. However, the roles of GLPS in regulating oxidative stress and mitochondrial dynamics in AD remain poorly understood. Here, the underlying mechanisms of neuroprotective effects on cognitive dysfunction in 5 × FAD mice were explored. C57BL/6 mice served as WT controls, while 5 × FAD mice were divided into an AD group and an AD + GLPS group. The mice in AD + GLPS group were administered daily GLPS (25 mg/kg) by i.p. injection for two months, while WT and AD mice received an equivalent volume of normal saline. The results indicated that GLPS markedly improved cognitive function and decreased p-tau and Aβ levels in 5 × FAD mice. Moreover, GLPS alleviated oxidative stress by increasing SOD levels and decreasing MDA concentrations. It also inhibited excessive mitochondrial fragmentation by decreasing the expression of p-Drp1 and Fis1, while increasing the levels of Mfn1, Mfn2, and OPA1 in 5 × FAD mice. Mechanistically, GLPS activated Nrf2, leading to a marked upregulation of antioxidant enzymes, including HO- 1, NQO1, and SOD2 in 5 × FAD mice. Collectively, these findings suggest that GLPS ameliorates cognitive deficits in 5 × FAD mice by reducing oxidative stress and modulating mitochondrial dynamics through Nrf2-mediated antioxidant enzyme activation.

Effect of triple helix polysaccharides from foxtail millet bran on millet starch gel formation

Polysaccharides as modifiers can solve native starch gel problem of weaker gel strength and lower gelation trend. The key structures of foxtail millet bran polysaccharides (FMBPs) in improving millet starch gel properties were investigated. Results showed that FMBPs were high molecular weight (Mw) heteropolysaccharides and the distribution of total sugar, uronic acid and monosaccharides was non-uniform in four FMBPs. Structural analysis revealed triple helix polysaccharides (THPs) existed in independent triple helix (ITH) and aggregates forms. The redshift degree of Congo red-FMBP complexes illustrated that FMBP-S1 contain the most ITHs, followed by FMBP-S2 and FMBP-S4, and the least in FMBP-S3. The porous structure of FMBPs promoted the adsorption of Congo red, bringing about the increase in weight and volume of the complexes and eventual precipitation. Separation of THPs provided a new method to investigate its role in starch gel. The results showed FMBPs with more ITHs showed higher peak viscosity, breakdown and setback. The presence of ITHs could reduce gel point temperature (ΔT = 6.62-29.86 °C) and water holding capacity (from 50 to 66 ms to 231 ms), but improve the viscoelasticity of gel. The study not only improved the quality of starch-based gel but also achieved high-value utilization of foxtail millet bran.

Polysaccharides with antioxidant activity: Extraction, beneficial roles, biological mechanisms, structure-function relationships, and future perspectives: A review

Polysaccharides are valuable macromolecules due to their multiple bioactivities, safety, and a wide range of sources. Recently, a series of polysaccharides with antioxidant activity have been intensively reported. In this review, the latest advances in polysaccharides with antioxidant activity have been reviewed, primarily based on the investigations of polysaccharides regarding advanced extraction methods, roles in oxidative stress-related diseases, intracellular signaling pathways associated with antioxidant responses, activating pathways in the gut, structure-function relationships, and methods to improve antioxidant activity. The summarized information highlighted that much work needs to be conducted, from laboratory to industry, to understand and fully utilize the antioxidant potential of polysaccharides. Finally, future perspectives, including scaling-up of advanced extraction methods, standardizing the protocols for assessing and screening polysaccharides, bridging gaps on the biological mechanisms underlying antioxidant activity, performing clinical trials, and elucidating structure-antioxidant relationships, have been addressed. The information present in this review will be helpful to the scientific community when studying on polysaccharides with antioxidant potential and provides research directions for a better understanding of the polysaccharides and promotes their successful applications in functional foods and nutraceuticals.

The degree of esterification influences the bioactivity of pectic polysaccharides isolated from Lithocarpus litseifolius

Pectic polysaccharides are the mainly bioactive components in Lithocarpus litseifolius (sweet tea) leaves. Nevertheless, owing to their diverse and complex chemical structures, the detailed structure-function relationships (SFR) of pectic polysaccharides from sweet tea (STP) are still unclear. Herein, the influence of STP's esterified degree on its diverse biological functions was uncovered. The results showed that the de-esterified STPs with a middle-esterified degree (33.53 %) and a low-esterified degree (7.66 %) were successfully prepared when compared with the original high-esterified STP (47.01 %), and their primary structural features were almost stable after the controllable de-esterification treatment. Furthermore, the findings inferred that STP's antioxidant, anti-diabetic, and immunostimulatory functions showed inverse correlations with the esterified degree. Moreover, the de-esterified STP with a lower-esterified degree could be more easily utilized by intestinal microorganisms to positively regulate the gut microbial composition. Overall, these findings can provide valuable insights for elucidating STP's precise SFR.

Ultrasonic-assisted enzymatic extraction, physicochemical properties and prebiotic activities of polysaccharides from Saccharomyces cerevisiae spore wall

Yeast wall polysaccharides (YWPs) are a bioactive compound found in the vegetative cells of Saccharomyces cerevisiae, contributing to its applications in food and medicine. YWPs have been extensively studied because of their diverse biological activities. Although the yeast spore wall of S. cerevisiae also contains polysaccharides, the biological activities of the components of the spores have received limited attention. In this study, yeast spore wall polysaccharides (YSWPs) were extracted from chs3Δ spores with exposed β-glucan layers via an ultrasonic-assisted enzymatic extraction (UAE) method, and the optimal extraction process was determined through single-factor and orthogonal experiments. The physicochemical properties of YWPs and YSWPs were compared under identical extraction conditions, and the effects of YSWPs on the abundance of the intestinal microflora and short-chain fatty acids (SCFAs) production in vitro were investigated. The results revealed that the optimal UAE process for YSWPs involves an ultrasonic power of 300 W, an ultrasonic duration of 60 min, an enzyme concentration of 1 % (w/w), and an enzymatic hydrolysis time of 4 h. The total sugar content of the extract was found to be 89.20 ± 0.52 %. The primary monosaccharides present in YSWPs are mannose and glucose, which are consistent with those found in the vegetative cell wall polysaccharides. Both YWPs and YSWPs exhibit similar physical properties, however, YSWPs has a smaller particle size, resulting in superior water-holding and oil-holding capacities. In simulations of in vitro colon fermentation, YSWPs can increased the population of beneficial microorganisms in the human intestine while reducing the number of harmful microbial populations. Additionally, it can effectively produced propionate and butyrate. These findings suggest that YSWPs can help maintain the intestinal ecological balance and promote intestinal health.

A Review on the Extraction, Structural Analysis, and Antitumor Mechanisms of Sanghuangporus Polysaccharides

In recent years, the bioactive compounds extracted from Sanghuangporus, especially polysaccharides, phenols, and triterpenoids, have attracted great interest from people due to their extensive biological activity. Among them, polysaccharides are mainly extracted from the seed bodies, mycelium, and fermentation broth of Sanghuangyuan, exhibiting notable effects including immunomodulation, antitumor properties, and hypoglycemic effects. This article provides a comprehensive review of the extraction process, structural characteristics, and antitumor mechanism of Sanghuangyuan polysaccharides. First, the different extraction methods, such as hot water extraction, enzyme-assisted extraction, and ultrasonic-assisted extraction, are summarized. Then, the structure of the Sanghuangporus polysaccharide is studied in detail. Moreover, the antitumor mechanisms demonstrate significant inhibitory impacts on various malignant tumors, spanning gastric, hepatic, colorectal, breast, and prostate cancers. This groundbreaking revelation is of great significance for both the food and pharmaceutical sectors, presenting innovative pathways for Sanghuangyuan utilization and potentially inducing advancements in product development, treatment modalities, and therapeutic interventions.

Foxtail millet bran dietary fibres foster in vitro beneficial gut microbes and metabolites while suppressing pathobionts

Foxtail millet bran soluble dietary fibre (MBSDF) is a dietary compound with various bioactivities, potentially modulated by the gut microbiota. To elucidate this bioregulatory mechanism, this study focused on the structureal composition and in vitro fermentation characteristics of MBSDF. The results revealed that MBSDF has a molecular weight of 18.26 kDa. The main chain is connected through a glycosidic bond in the form of →4)-α-D-Glcp-(1 → 4)-β-D-Xylp-(1→, being branched by →4, 6)-α-D-Glcp-(1 → O-6 and →3, 4)-β-D-Xylp-(1 → O3 bonds. After 24 h fermentation, the carbohydrate utilisation rate reached 59.15 %, with a decreased molecular weight and monosaccharide composition molar mass ratio. Meanwhile, a increase was observed in the short-chain fatty acid, accompanied by an increased relative abundance of Faecalibacterium, Bifidobacterium and Lactobacillus and suppressed growth of pathogenic Enterococcus. Interestingly, the modulation of gut homeostasis probably occurs via butyrate metabolism pathway. Collectively, MBSDF can selectively regulate the gut microbiota and their metabolites.

Research advances in okra polysaccharides: Green extraction technology, structural features, bioactivity, processing properties and application in foods

Okra polysaccharides, extracted from a lowcost plant, has gained abundant research interests recently for exhibiting notable antioxidant, hypoglycaemic, anti-inflammatory, and immunomodulatory capacities, catering for people's continuously increasing demand of safe, natural, and functional food ingredients. Meanwhile, okra polysaccharides are biocompatible materials with excellent processing properties such as water solubility, antimicrobial activity, elasticity, and viscosity. The present study generalizes the multiple biological activities and the extraction methods of okra polysaccharides, and discusses their various applications in food science. This review compares traditional and green extraction methods, reveals their impacts on the primary structures, and also elaborates the functional applications of okra polysaccharides in food industry including serving as emulsifiers, fat replacers, biofilms and microencapsulation materials. It aims to inform further research and discussions on okra polysaccharides. To our view, the development and application of okra polysaccharides should significantly contribute to the advancement of food industry and human health.

Multifaceted roles of plant-derived bioactive polysaccharides: A review of their biological functions, delivery, bioavailability, and applications within the food and pharmaceutical sectors

Plant-derived bioactive polysaccharides (PDBPs), versatile polymers originating from various botanical sources, exhibit a spectrum of biological functionalities crucial for human health. This review delves into the multifaceted roles of these bioactive compounds, elucidating their immune-boosting properties, antioxidant prowess, anti-inflammatory capabilities, and contributions to gut health. Amidst their pivotal roles, the efficiency of PDBPs delivery and bioavailability in the human system stands as a central determinant of their efficacy and utilization. This review paper extensively and systematically examines the diverse biological activities, such as immunomodulatory effects, delivery mechanisms like microencapsulation, and promising applications of PDBPs within the realms of both food (functional foods and nutraceuticals) and pharmaceutical (antimicrobial agents and anti-inflammatory drugs) sectors. Additionally, it offers a comprehensive overview of the classification, sources, and structural diversity of these polysaccharides, highlighting various identification techniques and rheological considerations. Moreover, the review addresses critical safety and regulatory concerns alongside global legislation about plant bioactive polysaccharides, envisaging a broader landscape for their utilization. Through this synthesis, we aim to underscore the holistic significance of PDBPs and their potential to revolutionize nutritional and therapeutic paradigms.

In vitro simulated digestion of different heat treatments sweet potato polysaccharides and effects on human intestinal flora

The aim of this study was to investigate the changes of untreated and steamed (100 °C, 20 min), fried (150 °C, 10 min), and baked (200 °C, 30 min) sweet potato polysaccharides during in vitro digestion and their effects on the intestinal flora. The results showed that the reducing sugar content of all four sweet potato polysaccharides increased significantly during digestion. During in vitro fecal fermentation, the content of reducing sugars and total carbohydrates decreased significantly. It indicated that all four polysaccharides showed degradation of polysaccharides during fermentation. Compared to the blank group, the total SCFAs content of the four polysaccharide sample groups was significantly increased. It was worth noting that sweet potato polysaccharides increased the percentage of Bacteroidetes and decreased the percentage of Proteobacteria in the intestinal flora. The findings provide evidence that sweet potato polysaccharides regulate intestinal flora and maintain intestinal health through interactions with intestinal flora.

Structural characteristics and potential antidepressant mechanism of a water-insoluble β-1,3-glucan from an edible fungus Wolfiporia cocos

A water-insoluble β-1,3-glucan (Wβ) with a molecular weight of 8.12 × 104 Da was extracted from an edible fungus Wolfiporia cocos. Its backbone was composed of 1,3-β-linked Glcp branched at the C-2, C-4, and C-6 positions, connecting more 1,3-β-linked Glcp with a triple helical structure. Wβ effectively ameliorated depressive symptoms, abnormality of neurotransmitters and inflammatory factors in chronic unpredictable mild stress (CUMS)-induced rats. Wβ also altered the composition of gut microbiota, especially Romboutsia, norank_f_Muribaculaceae and Ruminococcus. Integration of untargeted and targeted metabolomics and Western blotting analysis suggested that the short-chain fatty acids (SCFAs) and tryptophan metabolites were the most important metabolites involved in Wβ mediation. Wβ significantly modulated the levels of 7 SCFAs and 7 tryptophan metabolites, as well as the protein expression of two related enzymes (indoleamine-2,3-dioxygenase: IDO; kynurenine-3-monooxygenase: KMO). Our results suggest that Wβ exerts its antidepressant effect by influencing neurotransmitters and inflammatory factors through interactions between the gut microbiota, SCFA and tryptophan metabolites. The findings offer new insights into water-insoluble polysaccharides, especially β-glucan in structure analysis and utilization, and provide evidence that Wβ, a novel glucan from the often-discarded water-insoluble part of Wolfiporia cocos, has potential application in antidepressant health products.

Primary Study on Effect of Extraction Methods on the Properties and Activities of Polysaccharides from Geum japonicum var. Chinense F. Bolle

Geum japonicum Thunb. var. Chinese F. Bolle, a traditional Miao medicine with significant clinical potential, is rich in polysaccharides. Despite its importance, there is a scarcity of research on the structure and activities of these polysaccharides. In this study, polysaccharides from Geum japonicum (GJPs) were extracted using various methods, including heated reflux extraction (HRE), acidic extraction (ACE), alkaline extraction (AAE), microwave-assisted extraction (MAE), enzymatic extraction (EAE), pressurized liquid extraction (PLE), and deep eutectic solvents extraction (DESE). The extraction yield, physicochemical properties, structural characteristics, and antioxidant activities of these polysaccharides were comprehensively investigated and compared. Physicochemical analysis, including FT-IR spectral features and monosaccharide compositions, revealed that the GJPs are acidic heteropolysaccharides with both α- and β-configurations. DESE and ACE were the most effective methods for obtaining the highest neutral and acidic sugars with yields of 29.1%/64.2%, and 39.8%/55.6%, respectively. Meanwhile, AAE was preferable for extracting the polysaccharide-protein complex, achieving a yield of 14.21% and exhibiting superior thermal stability. In particular, DESE and PLE showed the best homogeneity with distinct molecular weights of 39.5 kDa and 17.6 kDa, respectively. In addition, biological evaluation indicated that DESE and MAE exhibited relatively stronger antioxidant activities as evidenced by DPPH and ABTS assays. Conversely, ACE demonstrated highest Fe2+ chelating ability but the lowest activity in DPPH and ABTS assays. Furthermore, the results of correlation analysis showed that the monosaccharides composition, protein and polyphenol content were significantly associated with the antioxidant activity. The choice of extraction method greatly affects the property and activity of G. japonicum polysaccharides. Polysaccharides extracted by deep eutectic solvents from G. japonicum show promise as natural antioxidants in the food and medicine industries.

Comparative analysis of phenolic compounds in different thinned unripe kiwifruits and their biological functions

Thinned unripe kiwifruits (TUK) are considered the major agro by-products in kiwifruit production. To promote their potential applications, polyphenols and biological effects of unripe fruits from nine commercial kiwifruit cultivars were compared. Our findings showed that TUK were rich in bioactive polyphenols, which varied greatly by different cultivars. Indeed, catechin, epicatechin, procyanidin PB1, procyanidin B2, protocatechuic acid, neochlorogenic acid, and gallic acid were measured as the major phenolic components in most TUK, with the highest levels observed in 'Hongao' and 'Cuiyu' cultivars. Furthermore, TUK exerted strong in vitro antioxidant capacities, inhibitory effects on digestive enzymes, and anti-inflammatory activities. Particularly, their stronger antioxidant effects and inhibitory effects on digestive enzymes were probably attributed to their higher contents of phenolic compounds, especially procyanidin B2. Collectively, our findings reveal that TUK are potential resources of valuable polyphenols, which can be exploited as natural antioxidants and natural inhibitors of α-glucosidase and α-amylase.

A review of in vitro antioxidant and antidiabetic polysaccharides: Extraction methods, physicochemical and structure-activity relationships

Nowadays, various plant polysaccharides have been successfully extracted which exhibited strong biological activities and might be useful for diabetes management. However, the effect of extraction methods, physicochemical and the structural-activity relationships of polysaccharides to exhibit antioxidants and antidiabetics were inadequate to explain their mechanism in action. The uses of advance extraction methods might be preferred to obtain higher antioxidants and antidiabetic activities of polysaccharides compared to conventional methods, but the determination of optimal extraction conditions might be crucial to preserve their structure and biological functions. Other than that, the physicochemical and structural properties of polysaccharides were closely related to their biological activities such as antioxidant and antidiabetic activities. Therefore, this review addressed the research gap of the influence of extraction methods, physicochemical and structural relationships of polysaccharides to biological activities, pointing out the challenges and limitations as well as future prospects to the current findings.

Recent advances in the combination of organic solvent-free extraction, chemical standardization, antioxidant assay, and cell culture metabolomics for functional food and its by-product

Functional foods and their by-products contain a wide range of bioactive components with an array of health benefits and were proposed to improve public health, well-being, and others. To achieve a circular economy, the processing and extraction of flavonoids, phenolic compounds, and others from functional food and agri-food wastes will require the use of environmentally friendly, sustainable, and a low-cost solution. Extraction methods that can eliminate the use of organic solvents, suitable for use in the laboratory and production of extracts will be covered. This will include subcritical water extraction (SBE), pressurized hot water extraction (PHWE), supercritical fluid extraction (SFE), and others. Based on the selected analytical methods, the determination of the marker or bioactive compounds and chemical fingerprints will provide the control measures to identify the batch-to-batch variation of the composition of the functional food products obtained. The combination of chemical standardization with antioxidant assay, such as DPPH and ABTS+ will provide further information on the quality of the extracts. Lastly, to ascertain the biological and physiological relevance of the antioxidant properties of the target sample, treatment of the antioxidant compounds or extracts was carried out using cellular models, and validated using other experimental endpoints, such as metabolomics.

Sequential extraction of hawthorn pectin: An attempt to reveal their original mode of being in plants and functional properties

Hawthorn is rich in pectin, which is much higher than most cultivated fruits, but conventional extraction methods do not meet the requirements of low energy consumption and green production. Pectin in hawthorn is divided into soluble and insoluble parts, and with the ripening of hawthorn, the original pectin is converted into soluble pectin and pectic acid under the action of enzymes. Therefore, based on the characteristics of hawthorn pectin, this study sequentially extracted hawthorn pectin using water-soluble pectin (WSP) and hot acid-soluble pectin (HAP) method, verifying the feasibility of extracting hawthorn pectin with pure water at room temperature, and systematically analyzing and comparing the physicochemical properties and functional characteristics of the two methods. The combination of texture analysis and gel rheology revealed that WSP formed a more uniform and dense network structure during the gelation process. Additionally, microscopic observations and emulsification index results indicated that the emulsion prepared with WSP (WSE) had a smaller particle size and better stability. This indicates that hawthorn pectin is suitable for extraction with pure water at room temperature, which can maintain its good physical properties while reducing energy consumption, providing a new approach for the large-scale extraction of pectin in the food industry.

Okra (Abelmoschus esculentus L.) Flour Integration in Wheat-Based Sourdough: Effect on Nutritional and Technological Quality of Bread

The aim of this study was to develop an innovative sourdough using dehydrated okra (Abelmoschus esculentus L.) pod flour and to use it in the production of bread. Three different flours (sun-dried S, freeze-dried F, oven-dried O) were individually mixed at 9% with wheat flour (Dough Yield 300) and fermented (N0: 8.0 log10 CFU/g) for 14 h, using Lactiplantibacillus plantarum ITM21B, Weissella cibaria C43-11 or Leuconostoc mesenteroides C43-2M. The results showed that after fermentation, the content of organic acids (lactic, acetic and propionic), exopolysaccharides (EPS), l-glutamic acid and total free amino acids (TFAA) increased and the high molecular weight proteins were converted into smaller proteins. Sourdough based on Leuc. mesenteroides and O flour (O_LeuMes) was selected to evaluate its applicability in bread making. It was included in the yeast-leavened bread formulation at 20 or 40% (0.6% and 1.21% w/w O flour replacement). The results showed that fermentation limited the negative effects of unfermented O flour on bread quality attributes, mainly the specific volume and firmness. Bread with O_LeuMes at 40% was improved in TFAA, EPS and l-glutamic acid content and showed a higher specific volume and lower moisture and firmness compared to bread with the unfermented O flour.

Polysaccharides from bile Arisaema exert an antipyretic effect on yeast-induced fever rats through regulating gut microbiota and metabolic profiling

In our previous study, bile Arisaema was elucidated to have a significant anti-febrile effect, but the pharmacodynamic material basis of this effect remains uncertain. Herein, we found that the soluble polysaccharide fraction from bile Arisaema presents a remarkable antipyretic effect through balancing the gut microbiota and regulating metabolic profiling. Bile Arisaema polysaccharide (BAP) was characterized for its monosaccharide composition with arabinose, galactose, glucose, mannose and xylose (0.028:0.072:0.821:0.05:0.029, molar ratios) and amino acid composition with arginine, threonine, alanine, glycine, serine, proline and tyrosine (109.33, 135.78, 7.22, 8.86, 21.07, 4.96, 12.31 μg/mg). A total of 50 peptides were identified from BAP using Ltq-Orbitrap MS/MS. The oral administration of 100 mg/kg BAP significantly increased the antipyretic effect in yeast-induced fever rats by comparing the rectal temperature. Mechanistically, the inflammation and disorders of neurotransmitters caused by fever were improved by treatment with BAP. The western blotting results suggested that BAP could suppress fever-induced inflammation by down-regulating the NF-κB/TLR4/MyD88 signaling pathway. We also demonstrated that BAP affects lipid metabolism, amino acid metabolism and carbohydrate metabolism and balances the gut microbiota. In summary, the present study provides a crucial foundation for determining polysaccharide activity in bile Arisaema and further investigating the underlying mechanism of action.

Effects of in vitro simulated digestion and fecal fermentation on the structure and regulating the glucose and lipid activity of a polysaccharide from Mori Folium

Mori folium, as a homologous drug-food, has hypoglycemic and lipid-lowering activity. Polysaccharides are the main bioactive ingredient of the Mori folium that exhibit diverse biological activities. In this study, a homogeneous polysaccharide (MP4) was purified and characterized from Mori folium. The changes of MP4 affected by saliva, simulated gastrointestinal juice, and human fecal fermentation, including physicochemical property or its bioactivity, were systematically investigated. Meanwhile, the influence of fermentation on the bioactivity were evaluated. The results showed that the backbone of MP4 is mainly composed of →4)-α-D-GalpA-(1→ residues. The molecular weight, the levels of reducing sugar content and free monosaccharides of MP4 exhibited no significant differences indicating that gastrointestinal digestion has a minimal effect on the physicochemical characteristics of MP4. However, during in vitro gut microbiota fermentation, MP4 are significantly degraded and utilized by gut microbiota, showing increased the production of short-chain fatty acids, notably acetic acid and propionic acid. The relative abundance of beneficial bacteria such as Bacteroidetes and Actinobacteria were significantly increased, whereas the levels of pathogenic bacteria such as Fusobacteria and Megamonas were significantly decreased, which changed the composition of the gut microbiota. The Firmicutes/Bacteroides ratio was also decreased significantly. Interestingly, after in vitro fermentation, the α-glucosidase inhibitory activity was increased, the lipase inhibitory activity and cholesterol adsorption activity was decreased. Correlation analysis showed that the relative abundance of some bacteria was significantly correlated with the bioactivities. These results provide a basis for the development of Mori folium polysaccharides as functional probiotic products.

Antitumor activity of Polygonatum sibiricum polysaccharides

Cancer is a global public health problem. Natural polysaccharides have been shown to enhance the effectiveness of cancer treatments. Polygonatum sibiricum (PS) has been used for millennia to treat diverse diseases. PS comprises numerous active constituents, including saponins, peptides, volatile oils, polysaccharides, and lectins. Many studies have highlighted the crucial role of polysaccharides in PS. Modern studies have shown that Polygonatum sibiricum polysaccharide (PSP) exhibits diverse pharmacological activities, including immunomodulatory, antitumor, antioxidant, and anti-aging effects. However, further study of the antitumor mechanisms is difficult because the activities of PSP are closely associated with its complex structural features and the different molecular weights of its components. Therefore, this review focuses on the research background and the extraction and purification of PSP. Studies related to the mechanism of the antitumor effects of PSP constituents of different molecular weights are also summarized, and perspectives on PSP research are presented.

Effect of ultrasound assisted H2O2/Vc treatment on the hyperbranched Lignosus rhinocerotis polysaccharide: Structures, hydrophobic microdomains, and antitumor activity

The effect of ultrasonic intensity (28.14, 70.35, and 112.56 W/cm2) on Lignosus rhinocerotis polysaccharide (LRP) degraded by ultrasound assisted H2O2/Vc system (U-H/V) was investigated. U-H/V broke the molecular chain of LRP and improved the conformational flexibility, decreasing the molecular weight, intrinsic viscosity ([η]) and particle size. The functional groups and hyperbranched structure of LRP were almost stable after U-H/V treatment, however, the triple helix structure of LRP was partially disrupted. With increasing ultrasonic intensity, the critical aggregation concentration increased from 0.59 mg/mL to 1.57 mg/mL, and the hydrophobic microdomains reduced. Furthermore, the LRP treated with U-H/V significantly inhibited HepG2 cell proliferation by inducing apoptosis. The increase in antitumor activity of LRP was closely associated with the reduction of molecular weight, [η], particle size and hydrophobic microdomains. These results revealed that U-H/V treatment facilitates the degradation of LRP and provides a better insight into the structure-antitumor activity relationship of LRP.

Characterization and biological activities of polysaccharides extracted from Auricularia auricula with different extraction methods

Polysaccharides derived from Auricularia auricula exhibit diverse biological activities and hold significant potential for commercial utilization as functional food ingredients. In this investigation, polysaccharides from A. auricula were obtained using six extraction techniques (ammonium oxalate solution extraction, sodium hydroxide solution extraction, hot water extraction, pectinase and cellulase-assisted extraction, ultrasonic-assisted extraction, and microwave-assisted extraction). Subsequently, a comprehensive comparison was conducted to evaluate their physicochemical properties and biological functionalities. The ammonium oxalate solution extraction method yielded a higher extraction rate (11.76%) and polysaccharide content (84.12%), as well as a higher uronic acid content (10.13%). Although the six Auricularia polysaccharides had different molecular weight distributions, monosaccharide molar ratios, similar monosaccharide compositions, and characteristic functional groups of polysaccharides, they exhibited different surface morphology. In vitro assays showed that polysaccharides extracted by ammonium oxalate solution possessed good scavenging ability against DPPH free radical, hydroxyl free radical and superoxide anion free radical as well as reduction power of iron ion. At the same time, both polysaccharides extracted by ammonium oxalate solution and sodium hydroxide solution promoted NO production in mouse macrophages along with the secretion of cytokines TNF-α, IL-1β, and IL-6. These results indicated significant differences in the structure and characteristics among Auricularia polysaccharides prepared by various extraction methods, which may be related to the variety or origin of A. auricula; furthermore, their bioactivities varied accordingly in vitro assays where the ammonium oxalate solution extraction method was found more beneficial for obtaining high-quality bioactive Auricularia polysaccharides.

Extraction, structures, biological effects and potential mechanisms of Momordica charantia polysaccharides: A review

Momordica charantia L. is a kind of vegetable with medicinal value. As the main component of the vegetable, Momordica charantia polysaccharides (MCPs) mainly consist of galactose, galacturonic acid, xylose, rhamnose, mannose and the molecular weight range is 4.33 × 103-1.16 × 106 Da. MCPs have been found to have various biological activities in recent years, such as anti-oxidation, anti-diabetes, anti-brain injury, anti-obesity, immunomodulatory and anti-inflammation. In this review, we systematically summarized the extraction methods, structural characteristics and physicochemical properties of MCPs. Especially MCPs modulate gut microbiota and cause the alterations of metabolic products, which can regulate different signaling pathways and target gene expressions to exert various functions. Meanwhile, the potential structure-activity relationships of MCPs were analyzed to provide a scientific basis for better development or modification of MCPs. Future researches on MCPs should focus on industrial extraction and molecular mechanisms. In East Asia, Momordica charantia L. is used as both food and medicine. It is not clear whether MCP has its unique biological effects. Further study on the difference between MCPs and other food-derived polysaccharides will be helpful to the development and potential application of Momordica charantia L.

Study on fermentation preparation, physicochemical properties and biological activity of carboxymethylpachymaran with different degrees of substitution

BACKGROUND

Carboxymethylpachymaran (CMP) is created by carboxymethylating pachyman (PM), which increases its water solubility and enhances a number of biological activities. Traditional polysaccharides modified by carboxymethylation employ strong chemical techniques. Carboxymethylcellulose (CMC) has been used previously for liquid fermentation to carboxymethyl modify bacterial polysaccharides. This theory can be applied to fungal polysaccharides because Poria cocos has the ability to naturally utilize cellulose.

RESULTS

CMC with different degrees of substitution (DS) (0.7, 0.9 and 1.2) were added to P. cocos fermentation medium, and CMPs with different DS (0.38, 0.56 and 0.78, respectively) were prepared by liquid fermentation. The physical and chemical properties and biological activities of the CMPs were determined. Their structures were confirmed by Fourier transform infrared (FTIR) spectroscopy and monosaccharide composition. With the increase of DS, the viscosity and viscosity-average molecular weight of CMPs decreased, whereas polysaccharide content and water solubility increased, although the triple helix structure was not affected. The results of bioactivity assay showed that the higher the DS of CMPs, the higher the 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, and the stronger the bacterial inhibition ability.

CONCLUSION

The present study has developed a method for producing CMPs by P. cocos liquid fermentation. The results of the study confirm that enhancing the DS of CMP could effectively enhance its potential biological activity. The findings provide safe and reliable raw materials for creating CMP-related foods and encourage CMP application in the functional food industry. © 2024 Society of Chemical Industry.

Characterization, antioxidant activity and in vitro digestion of hawthorn pectin prepared by gradient ethanol precipitation

Four modified hawthorn pectin fractions (MHPs), named MHP-30, MHP-50, MHP-70 and MHP-90, were obtained by ultrasonic-assisted pectin methyl esterase modification and gradient ethanol precipitation. The results indicated that all four MHPs were composed of galacturonic acid, galactose, xylose, arabinose, glucose and mannose in different proportions. With the increase of the ethanol concentration, the molecular weight, esterification degree and galacturonic acid content of MHPs all decreased, whereas the arabinose content and branching degree increased. The structural characterization from XRD, SEM, and FT-IR showed that four MHPs exhibited amorphous structure, similar functional groups, diverse surface morphologies. Besides, in vitro antioxidant assays confirmed that MHP-70 and MHP-90 exhibited stronger total antioxidant activities than MHP-30 and MHP-50. The results of simulated saliva-gastrointestinal digestion showed that the molecular weight of MHP-70 and MHP-90 remained stable, yielded small amounts of reducing sugars, and were resistant to digestion in the human upper digestive tract. Overall, MHP-70 and MHP-90 shown great potential as novel natural antioxidants, which are expected to be good carbon sources for the utilization of intestinal microorganisms.

Steam Explosion-Assisted Extraction of Polysaccharides from Pleurotus eryngii and Its Influence on Structural Characteristics and Antioxidant Activity

Pleurotus eryngii (PE) has been sought after for its various health benefits and high content of phenolic compounds. This study explored the feasibility of steam explosion (SE)-assisted extraction of polysaccharides with high antioxidant capacities from PE. An orthogonal experimental design (OED) was used to optimize the SE-assisted extraction of PE. The influence of the optimized SE-assisted extraction on the physicochemical properties of PE polysaccharides was determined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), monosaccharide compositional analysis and antioxidant capacity assays. Under optimal SE conditions, SE-assisted extraction increased the polysaccharide yield by 138% compared to extraction without SE-assistance. In addition, SEM demonstrated that SE-assisted extraction markedly altered the spatial structure of Pleurotus eryngii polysaccharides (PEP), and monosaccharide compositional analysis revealed that this pretreatment significantly increased the proportions of some monosaccharides, such as glucose, rhamnose and arabinose, in the isolated PEP. FTIR spectra indicated no change in the major chemical functional groups of PEP. PEP extracted by SE-assisted extraction had significantly increased free radical scavenging and antioxidant capacities. In conclusion, SE-assisted extraction appears to be a novel polysaccharide extraction technology, which markedly increases extraction yields and efficiency and can increase the biological activity of polysaccharide extracts.

Characterization of the Structure and Physicochemical Properties of Soluble Dietary Fiber from Peanut Shells Prepared by Pulsed Electric Fields with Three-Phase Partitioning

This study evaluated the impact of pulsed electric fields (PEFs) combined with three-phase partitioning (TPP) extraction methods on the physicochemical properties, functional properties, and structural characterization of the soluble dietary fiber (SDF) derived from peanut shells (PS). The findings of this study indicated that the application of a PEF-TPP treatment leads to a notable improvement in both the extraction yield and purity of SDF. Consequently, the PEF-TPP treatment resulted in the formation of more intricate and permeable structures, a decrease in molecular weight, and an increase in thermal stability compared to SDFs without TPP treatment. An analysis revealed that the PEF-TPP method resulted in an increase in the levels of arabinose and galacturonic acid, leading to enhanced antioxidant capacities. Specifically, the IC50 values were lower in SDFs which underwent PEF-TPP (4.42 for DPPH and 5.07 mg/mL for ABTS) compared to those precipitated with 40% alcohol (5.54 mg/mL for DPPH, 5.56 mg/mL for ABTS) and PEF75 (6.60 mg/mL for DPPH, 7.61 mg/mL for ABTS), respectively. Notably, the SDFs which underwent PEF-TPP demonstrated the highest water- and oil-holding capacity, swelling capacity, emulsifying activity, emulsion stability, glucose adsorption, pancreatic lipase inhibition, cholesterol adsorption, nitric ion adsorption capacity, and the least gelation concentration. Based on the synthesis scores obtained through PCA (0.536 > -0.030 > -0.33), which indicated that SDFs which underwent PEF-TPP exhibited the highest level of quality, the findings indicate that PEF-TPP exhibits potential and promise as a method for preparing SDFs.

Optimization of ultrasound-assisted extraction of Imperata cylindrica polysaccharides and evaluation of its anti-oxidant and amelioration of uric acid stimulated cell apoptosis

An efficient, cost-effective and environmentally friendly ultrasound-assisted hot water method for Imperata cylindrica polysaccharide (ICPs) extraction was developed. According to the response surface results, the optimal ultrasonic time was 85 min, ultrasonic power was 192.75 W, temperature was 90.74 °C, liquid-solid ratio was 26.1, and polysaccharide yield was 28.50 %. The polysaccharide mainly consisted of arabinose (Ara), galactose (Gal), and glucose (Glc), with a molecular weight of 62.3 kDa. Ultrasound-assisted extraction of Imperata cylindrica polysaccharide (UICP) exhibited stronger anti-oxidant activity and ability to ameliorate cellular damage due to uric acid stimulation compared with traditional hot water extraction of Imperata cylindrica polysaccharide (ICPC-b). It also exhibited higher thermal stability, indicating its potential value for applications in the food industry.

Impact of internal metal ions in tea polysaccharides on antioxidant potential and suppression of cancer cell growth

Four kinds of tea polysaccharides (MBTPS, MGTPS, ZBTPS, ZGTPS) were extracted from Maofeng black tea, Maofeng green tea,Ziyan black tea and Ziyan green tea, and then four tea polysaccharides (RMBTPS, RMGTPS, RZBTPS, RZGTPS) after metal removal were prepared. The physicochemical properties, antioxidant activity and inhibitory activity on cancer cell proliferation of the above polysaccharides were studied. The composition analysis shows that these tea polysaccharides were glycoproteins complexes, composed of a variety of monosaccharides, and the removal of metal ions did not lead to fundamental changes in the composition of polysaccharides. In vitro activity, after removing metal ions, the ABTS free radicals scavenging ability and reducing power of tea polysaccharides were decreased, and the inhibitory effect on proliferation of H22 cells weakened. There was a great correlation between metal elements Al and Ni and biological activity. The results showed that the metal ions in tea polysaccharides, especially Al and Ni, had positive effects on biological activity.

Gut microbiota modulation, prebiotic and bioactive characteristics of date pomace polysaccharides extracted by microwave-assisted deep eutectic solvent

This study investigated the characteristics of polysaccharides from date pomace using microwave-assisted deep eutectic solvents. The impact on the gut microbiota and probiotics growth was examined in vitro. The study also examined its antioxidant properties, ability to inhibit enzymes linked to diabetes and high blood pressure, impact on cell growth, and physical properties. The isolated MPS had an average molecular weight of 8073.38 kDa and contained mannose, galacturonic acid, galactose, glucose, and fructose in specific proportions. At a concentration of 1000 mg/L, MPS showed strong antioxidant activity, with significant scavenging rates in various tests such as DPPH (57.0 ± 1.05 %) and ABTS (66.4 ± 2.48 %). MPS displayed 77 %, 80 %, and 43 % inhibition for α-amylase, α-glucosidase, and ACE-inhibition, respectively. MPS displayed significant antiproliferative effects, achieving 100 % and 99 % inhibition against Caco-2 and MCF-7 cells at 2500 mg/L, respectively. MPS showed broad-spectrum antibacterial properties against both Gram-positive and Gram-negative foodborne bacteria. Gemmiger formicilis, Blautia species, Collinsella aerofaciens, and Bifidobacterium longum showed strong positive correlations, suggesting increased SCFA production. Network analysis indicated species correlations, with 86 % showing negative correlations with Escherichia and Enterococcus saccharolyticus. MPS was abundant in Firmicutes, Actinobacteria, and Proteobacteria phyla. Date pomace could serve as a dietary fiber source, promoting better health.

Effect of hydrochloric acid and citric acid with ultrasound processing on characteristics of superfine-ground pectic polysaccharides from okra (Abelmoschus esculentus L.) peel

The structural properties and biological activities of okra pectic polysaccharides (OPs) were impacted by various extraction methods. Based on commonly grinding (40, 100 meshes) and superfine grinding okra powders, two extraction solvents (hydrochloric acid, HA; citric acid, CA) were used firstly. Next, the extraction yield, physical and chemical properties, molecular structure and functional properties of OPs were analyzed by non-ultrasonic treatment and ultrasound-assisted superfine grinding method. The outcomes demonstrated that the extraction yield of OPs rose as the particle size of the powder decreased. HA-OPs had higher molecular weight (Mw), apparent viscosity and emulsification ability than CA-OPs. CA-OPs had higher esterification degree (DE), solubility and total sugar content, and higher amounts of rhamnogalacturonan-I (RG-I) segments. Compared with OPs without ultrasound-assisted extraction, ultrasound-assisted superfine grinding extraction exhibited higher sugar content, antioxidant capacity, emulsification ability, lower Mw, DE and apparent viscosity. Finally, the correlation between structure and function of OPs was further quantified. The antioxidant capacity was positively correlated with RG-I content, and negatively correlated with DE and Mw. The emulsification ability was mainly positively correlated with the GlcA of OPs. This study provides a theoretical basis for the development of OPs foods with clear structure-function relationship, which would be instructive for the application of OPs in food and cosmetics.

Review of isolation, purification, structural characteristics and bioactivities of polysaccharides from Portulaca oleracea L

Portulaca oleracea L., also known as purslane, affiliates to the Portulacaceae family. It is an herbaceous succulent annual plant distributed worldwide. P. oleracea L. is renowned for its nutritional value and medicinal value, which has been utilized for thousands of years as Traditional Chinese Medicine (TCM). The extract derived from P. oleracea L. has shown efficacy in treating various diseases, including intestinal dysfunction and inflammation. Polysaccharides from P. oleracea L. (POP) are the primary constituents of the crude extract which have been found to have various biological activities, including antioxidant, antitumor, immune-stimulating, and intestinal protective effects. While many publications have highlighted on the structural identification and bioactivity evaluation of POP, the underlying structure-activity relationship of POP still remains unclear. In view of this, this review aims to focus on the extraction, purification, structural features and bioactivities of POP. In addition, the potential structure-activity relationship and the developmental perspective for future research of POP were also explored and discussed. The current review would provide a valuable research foundation and the up-to-date information for the future development and application of POP in the field of the functional foods and medicine.

Effect of Lactiplantibacillus plantarum fermentation on the physicochemical, antioxidant activity and immunomodulatory ability of polysaccharides from Lvjian okra

Okra polysaccharides exhibits a range of biological activities. To date, its processing using microbial fermentation has not been explored. This study investigated the fermentation of okra juice with various lactic acid bacteria, followed by the extraction and characterization of crude polysaccharides (termed OPS-F), in contrast to their non-fermented counterpart (OPS). Changes in physicochemical properties, antioxidant activity and immunomodulatory ability were noted. The results demonstrated that OPS-F had a 7.42-12.53 % increase in total polysaccharides content compared to OPS. However, high-performance size-exclusion chromatography indicated a reduction in the molecular weight of OPS-F (7.9-9.5 × 105 Da) relative to OPS (1.66 × 106 Da). Compared to OPS, OPS-F had reduced levels of mannose, glucose, glucuronic acid and arabinose, but increased rhamnose, galacturonic acid and galactose, exhibiting enhanced solubility and lower apparent viscosity. Fourier transform infrared spectroscopy and nuclear magnetic resonance analysis showed minimal changes in polysaccharide structure post-fermentation. Moreover, despite a decrease in antioxidant activity post-fermentation, OPS-F exhibited superior immunomodulatory potential. In conclusion, fermenting okra juice with lactic acid bacteria alters the physicochemical properties of crude polysaccharides and enhances their immunomodulatory activity, offering a promising approach for developing new functional food resources.

Physicochemical, rheological, antioxidant and immunological properties of four novel non-inulin (poly)saccharides from Asparagus cochinchinensis

The impacts of four extraction techniques, including hot water, ultrasonic-assisted, complex enzyme-assisted and acid-assisted methods, on the morphological, physicochemical properties and bioactivities of Asparagus cochinchinensis (poly)saccharides (EACP, WACP, UACP, and AACP) were investigated and compared. The four samples were mainly composed of glucose, fructose, and galactose with molar ratios of 50.8:22.7:4.4 for WACP, 53.9:26.0:5.3 for UACP, 35.6:14.1:21.4 for AACP and 45.0:15.6:9.0 for EACP, respectively. The rheological result showed that ACPs were non-Newtonian fluids. EACP with high purity (97.65 %) had good DPPH, O2- and ABTS+ radical scavenging activities, and significantly promoted the proliferation of the RAW264.7 cells at low concentration. UACP had good Fe2+ chelating ability, radical (DPPH, O2- and OH) scavenging activities, which might be attributed to the existence of triple-helix structure. AACP had high yield, molecular weight (17,477.2 Da), high crystallinity (23.33 %), and good radical (OH and ABTS+) scavenging activities. All four significantly stimulated the transcript expression levels of TNF-α, IL-1β and IL-6, as determined by RT-PCR. These results suggest that the exploitation and utilization of non-inulin (poly)saccharides extracted by ultrasonic-assisted, complex enzyme-assisted and acid-assisted extraction methods are potentially valuable as effective and natural immune adjuvants and antioxidants.

Yang-Xin-Shu-Mai granule alleviates atherosclerosis by regulating macrophage polarization via the TLR9/MyD88/NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Previous studies have found that Yang-Xin-Shu-Mai granule (YXSMG) has certain advantages in the treatment of stable coronary heart disease. However, YXSMG can inhibit the progression of atherosclerotic plaque and stabilize vulnerable plaque needs to be further explored and studied. This research, mass spectrometry analysis, network pharmacology, in vivo and in vitro experimental studies were conducted to explore the mechanism of YXSMG on atherosclerosis.

AIM OF THE STUDY

To decipher the mechanism of atherosclerotic plaque, stabilization for YXSMG by analysis of its active ingredients and biological network and activity in whole animal and at cellular and molecular levels.

METHODS

The active components of YXSMG were determined using high performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) analysis. The 'Disease-Compound-Target-Pathway' network diagram was constructed using network pharmacology, and the stability of binding between core targets and core compounds was analyzed with molecular docking. After intervention with YXSMG, the pathology of aortic plaque, inflammation in the surrounding tissue, expression of TLR9/MyD88/NF-κB pathway protein in plaque and M1/M2 polarization of plaque macrophages were evaluated in vivo in apolipoprotein E-deficient (ApoE-/-) mice fed with high-fat diet. To verify whether it suppressed inflammation by inhibiting Toll-like receptor 9 (TLR9) reprogramming of macrophage polarization, we used RAW264.7 macrophages treated with specific TLR9 agonist (ODN1826) and inhibitor (ODN2088).

RESULTS

Five active compounds were identified in YXSMG: catechin, formononetin, tanshinone IIA, cryptotanshinone and glycitein. Network pharmacology studies revealed TLR9 as one of the core targets of YXSMG intervention in atherosclerosis. Computer simulation of molecular docking showed that TLR9 could interact with the core compound to form a stable complex. In vivo experiments confirmed that YXSMG could significantly inhibit atherosclerotic plaque, reduce levels of blood lipids and inflammatory factors, downregulate TLR9/MyD88/NF-κB pathway protein and inhibit aortic sinus macrophages polarization to M1, but promote their polarization to M2 to inhibit inflammation. In vitro experiments revealed that YXSMG could downregulate expression of TLR9 gene and protein in ODN1826-activated RAW264.7 macrophages. ODN2088 had a synergistic effect with YXSMG on the TLR9/MyD88/NF-κB signaling pathway, and reprogrammed macrophages polarization from M1 to M2 by inhibiting TLR9, thus reducing immuno-inflammatory response.

CONCLUSION

YXSMG can reduce the level of blood lipid and improve the size of atherosclerotic plaque and inflammatory infiltration in ApoE-/- mice fed with high fat. It is concluded that YXSMG can improve the mechanism of atherosclerotic plaque by inhibiting TLR9/MyD88/NF-κB pathway reprogramming macrophage M1/M2 polarization and reducing arterial inflammation.

Innovative biocatalyst synthesis of pectinolytic enzymes by cross-linking strategy: Potentially immobilised pectinases for the production of pectic-oligosaccharides from pectin

Pectinases are outstanding multienzymes, which have the potential to produce new emerging pectic-oligosaccharides (POS) via enzymatic hydrolysis of pectin. However, free pectinase is unable to undergo repeated reaction for the production of POS. This study proposed a sustainable biocatalyst of pectinases known as cross-linked pectinase aggregates (CLPA). Pectinase from Aspergillus aculeatus was successfully precipitated using 2 mg/mL pectinase and 60 % acetone for 20 min at 20 °C, which remained 36.3 % of its initial activity. The prepared CLPA showed the highest activity recovery (85.0 %), under the optimised conditions (0.3 % (v/v) starch and glutaraldehyde mixture (St/Ga), 1.5: 1 of St/Ga, 25 °C, 1.5 h). Furthermore, pectin-degrading enzymes from various sources were used to produce different CLPA. The alteration of pectinase secondary structure gave high stability in acidic condition (pH 4), thermostability, deactivation energy and half-life, and improved storage stability at 4 °C for 30 days. Similarly to their free counterpart, the CLPA exhibited comparable enzymatic reaction kinetics and could be reused eight times with approximately 20 % of its initial activity. The developed CLPA does not only efficaciously produced POS from pectin as their free form, but also exhibited better operational stability and reusability, making it more suitable for POS production.

Green extraction of polysaccharides from Camellia oleifera fruit shell using tailor-made deep eutectic solvents

Camellia oleifera fruit shells are often discarded as byproducts in the C. oleifera industry. There is a general interest in isolating high-value natural products to valorize those fruit shells with green, rapid, and effective extraction methods. This study employed 43 combinations of deep eutectic solvents (DESs) to extract polysaccharides from C. oleifera fruit shells. Two choline chloride-based DESs and a ternary DES with propionic acid and 1,3-butanediol as hydrogen bond donors exhibited relatively high extraction efficiency. The polysaccharide yield reached 15.03 ± 0.35 % under optimized extraction time (55 min), extraction temperature (70 °C), and DES water content (33.33 %). The physicochemical composition and preliminary structure of obtained polysaccharides were characterized. Additionally, DESs-extracted polysaccharides exhibited higher in vitro antioxidant activities and hypoglycemic effects compared to water-extracted polysaccharides. These findings suggested that the optimized DES-assisted extraction method could be a potential approach for polysaccharides extraction from C. oleifera.

Comparative Study of the Structural Characteristics and Bioactivity of Polysaccharides Extracted from Aspidopterys obcordata Hemsl. Using Different Solvents

The polysaccharides extracted from Aspidopterys obcordata are thought to have anti-urolithiasis activity in Drosophila kidney stones. This study aimed to assess the effects of different extraction solvents on the yield, chemical composition, and bioactivity of polysaccharides from A. obcordata. A. obcordata polysaccharides were extracted by using four solutions: hot water, HCl solution, NaOH solution, and 0.1 M NaCl. The results revealed that the extraction solvents significantly influenced the extraction yields, molecular weight distribution, monosaccharide compositions, preliminary structural characteristics, and microstructures of polysaccharides. The NaOH solution's extraction yield was significantly higher than the other extraction methods. Vitro antioxidant activity assays revealed that the NaOH solution extracted exhibited superior scavenging abilities towards DPPH and ABTS radicals and higher FRAP values than other polysaccharides. The vitro assays conducted for calcium oxalate crystallization demonstrated that four polysaccharides exhibited inhibitory effects on the nucleation and aggregation of calcium oxalate crystals, impeded calcium oxalate monohydrate growth, and induced calcium oxalate dihydrate formation. The NaOH solution extracted exhibited the most pronounced inhibition of calcium oxalate crystal nucleation, while the hot water extracted demonstrated the most significant suppression of calcium oxalate crystal aggregation. Therefore, it can be inferred that polysaccharides extracted with NaOH solution exhibited significant potential as a viable approach for extracting polysaccharides from stems due to their superior yield and the remarkable bioactivity of the resulting products.

Antitumor effects of polysaccharides from medicinal lower plants: A review

Cancer is one of the leading causes of death worldwide, yet the drugs currently approved for cancer treatment are associated with significant side effects, making it urgent to develop alternative drugs with low side effects. Polysaccharides are natural polymers with ketone or aldehyde groups, which are widely found in plants and have various biological activities such as immunomodulation, antitumor and hypolipidemic. The lower plants have attracted much attention for their outstanding anticancer effects, and many studies have shown that medicinal lower plant polysaccharides (MLPPs) have antitumor activity against various cancers and are promising alternatives with potential development in the food and pharmaceutical fields. Therefore, this review describes the structure and mechanism of action of MLPPs with antitumor activity. In addition, the application of MLPPs in cancer treatment is discussed, and the future development of MLPPs is explored.

The digestive behavior of pectin in human gastrointestinal tract: a review on fermentation characteristics and degradation mechanism

Pectin is widely spread in nature and it develops an extremely complex structure in terms of monosaccharide composition, glycosidic linkage types, and non-glycosidic substituents. As a non-digestible polysaccharide, pectin exhibits resistance to human digestive enzymes, however, it is easily utilized by gut microbiota in the large intestine. Currently, pectin has been exploited as a novel functional component with numerous physiological benefits, and it shows a promising prospect in promoting human health. In this review, we introduce the regulatory effects of pectin on intestinal inflammation and metabolic syndromes. Subsequently, the digestive behavior of pectin in the upper gastrointestinal tract is summarized, and then it will be focused on pectin's fermentation characteristics in the large intestine. The fermentation selectivity of pectin by gut bacteria and the effects of pectin structure on intestinal microecology were discussed to highlight the interaction between pectin and bacterial community. Meanwhile, we also offer information on how gut bacteria orchestrate enzymes to degrade pectin. All of these findings provide insights into pectin digestion and advance the application of pectin in human health.

Advance in Morchella sp. polysaccharides: Isolation, structural characterization and structure-activity relationship: A review

Morchella sp. is a kind of precious medicinal and edible fungus with a unique flavor and is rich in various amino acids and organic germanium needed by the human body. Most notably, Morchella sp. polysaccharides have attracted widespread attention due to their significant bioactivity in recent years. At present, extensive studies have been carried out on the extraction methods, structural characterization and activity evaluation of Morchella sp. polysaccharides, which provides a good theoretical basis for its further development and application. However, the systematic summary of the related research of Morchella sp. polysaccharides has not been reported yet. Therefore, this review mainly focused on the isolation and purification methods, structural characterization, biological activities and structure-activity relationship of Morchella sp. polysaccharides. This work will help to have a better in-depth understanding of Morchella sp. polysaccharides and provide a scientific basis and direct reference for more scientific and rational applications.

In vitro fermentation of Gracilaria lemaneiformis and its sulfated polysaccharides by rabbitfish gut microbes

This study intended to characterize the Gracilaria lemaneiformis (SW)-derived polysaccharide (GLP) and explore the fermentation aspects of SW and GLP by rabbitfish (Siganus canaliculatus) intestinal microbes. The GLP was mainly composed of galactose and anhydrogalactose (at 2.0:0.75 molar ratio) with the linear mainstay of α-(1 → 4) linked 3,6-anhydro-α-l-galactopyranose and β-(1 → 3)-linked galactopyranose units. The in vitro fermentation results showed that the SW and GLP could reinforce the short-chain fatty (SCFAs) production and change the diversity and composition of gut microbiota. Moreover, GLP boosted the Fusobacteria and reduced the Firmicutes abundance, while SW increased the Proteobacteria abundance. Furthermore, the adequacy of feasibly harmful bacteria (such as Vibrio) declined. Interestingly, most metabolic processes were correlated with the GLP and SW groups than the control and galactooligosaccharide (GOS)-treated groups. In addition, the intestinal microbes degrade the GLP with 88.21 % of the molecular weight reduction from 1.36 × 105 g/mol (at 0 h) to 1.6 × 104 g/mol (at 24 h). Therefore, the findings suggest that the SW and GLP have prebiotic potential and could be applied as functional feed additives in aquaculture.

Extraction, Isolation, Screening, and Preliminary Characterization of Polysaccharides with Anti-Oxidant Activities from Oudemansiella raphanipies

Response surface methodology (RSM) was used to find the optimal extraction process of Oudemansiella raphanipies polysaccharides (ORPs). The results showed that the optimal extraction parameters were an alkali concentration of 0.02 mol/L, a ratio of material to liquid of 1:112.7 g/mL, an extraction temperature of 66.0 °C, and an extraction time of 4.0 h. Under the optimal conditions, the yield of ORPs was raised to 16.2 ± 0.1%. The antioxidant activities of ORPs-I~V were determined and compared, and ORPs-V was further purified by chromatography, with an average molecular weight (Mw) of 18.86 kDa. The structure of ORPs-V was determined by Fourier transform-infrared spectroscopy (FT-IR), monosaccharide analysis, and nuclear magnetic resonance (NMR) spectroscopy. The ORPs-V comprised fucose, rhamnose, arabinose, glucose, galactose, mannose, xylose, fructose, galacturonic acid, and glucuronic acid at a ratio of 1.73:1.20:1.13:2.87:8.71:2.89:1.42:0.81. Compared to other ORPs, ORPs-V showed the strongest antioxidant activities (ABTS radical cation, hydroxyl radical and DPPH scavenging activities, and reducing power), and were able to significantly increase the activities of superoxide dismutase, catalase, lactate dehydrogenase, and glutathione peroxidase. However, they reduced the malondialdehyde content in mice fed a high-fat diet. These results indicate that ORPs-V may be good anti-oxidant agents to be applied in functional foods.

Extraction, Rheological, and Physicochemical Properties of Water-Soluble Polysaccharides with Antioxidant Capacity from Penthorum chinense Pursh

This study aimed to isolate polysaccharides from Penthorum chinense Pursh and evaluate their rheological characteristics, physicochemical properties, and antioxidant activity. The optimal conditions for the maximal extraction yield of Penthorum chinense Pursh polysaccharides (4.05 ± 0.12%) were determined by employing a single-factor test and response surface methodology which included an extraction time of 3 h, a liquid-solid ratio of 20 mL/g, and three separate extraction times. The rheological experiments showcased that the P. chinense polysaccharides exhibited typical shear-thinning behavior, with their apparent viscosity being influenced by various parameters such as concentration, pH, temperature, salt content, and freeze-thaw. The purified polysaccharides (PCP-100), having an average molecular weight of 1.46 × 10⁶ Da, mainly consisted of glucose (18.99%), arabinose (22.87%), galactose (26.72%), and galacturonic acid (21.89%). Furthermore, the PCP-100 exhibited high thermal stability and displayed an irregular sheet-like morphology. Its superior reducing power and free radical scavenging ability implied its significant antioxidant activity in vitro. Collectively, these findings provide important insights for the future application of P. chinense polysaccharides in the food industry.