A review of the antibacterial activity and mechanisms of plant polysaccharides

The therapeutic role of Azadirachta indica leaves ethanolic extract against detrimental effects of Aeromonas veronii infection in Nile tilapia, Oreochromis niloticus

Bacterial pathogens cause high fish mortalities and in turn economic losses in fish farms. Innovative strategies should be applied to control bacterial infections instead of antibiotics to avoid the resistance problem. Consequently, the present investigation studied the curative potential of Azadirachta indica leave ethanolic extract (AILEE) on Aeromonas veronii infection in Oreochromis niloticus. A preliminary trial was assessed to evaluate the curative dose of AILEE which was found to be 2.5 mg/L. One hundred and sixty fish were divided into equal four groups in four replications, where group 1 and group 2 were non-challenged and treated with 0- and 2.5-mg/L AILEE, respectively. Group 3 and group 4 were challenged with A. veronii and treated with 0- and 2.5-mg/L AILEE, respectively for 10 days. A. veronii infection produced severe clinical manifestations and a high mortality rate in the infected fish. Furthermore, the infected fish exhibited a significant rise in the hepatorenal indices (aspartate aminotransferase, alanine aminotransferase, and creatinine), the oxidant biomarker (malondialdehyde), and the stress indicators (glucose and cortisol). A significant reduction in the protein profile and antioxidant/immune parameters (catalase, immunoglobulin M, lysozyme, nitric oxide, and phagocytic activity) was observed in the infected fish. Water application of the infected group to 2.5-mg/L AILEE notably ameliorated the hepatorenal indices, the oxidant biomarker, and the stress indicators. Furthermore, AILEE improved the antioxidant/immune indices. Water application of 2.5-mg/L AILEE could be useful against A. veronii infection in O. niloticus culture.

A review of the polysaccharides against fatigue and the underlying mechanism

Fatigue is a common physiological state that affects normal human activities. Prolonged fatigue induces a variety of diseases and seriously affects human health, so it is imperative to discover nutritional dietary supplements and treatments without side effects, among which natural anti-fatigue polysaccharides have shown great potential. Polysaccharides, a class of biomolecules produced by a variety of organisms such as plants, animals, bacteria and algae, have attracted much attention in recent years due to their anti-fatigue activity and fewer side effects. This review summarizes the classification, dosage and experimental models of polysaccharides with anti-fatigue activity obtained from different natural sources. We also review the fatigue-relieving effects of these polysaccharides through mechanisms such as modulating oxidative damage, regulating energy metabolism and influencing intestinal flora, as well as the effects of molecular weights, monosaccharide compositions, structural features and chemical modifications of the polysaccharides on their anti-fatigue activities to support their potential application value in functional foods and pharmaceuticals. New valuable insights for future research on natural polysaccharides are also presented in the field of natural production of bio-based functional materials, functional foods and therapeutic agents.

Heat-sealable, transparent, and degradable arabinogalactan/polyvinyl alcohol films with UV-shielding, antibacterial, and antioxidant properties

Petroleum-based packaging materials are nondegradable and unsustainable and thus are harmful to the environment. Renewable packaging films prepared from bio-based raw materials are promising alternatives to petroleum-based packaging materials. In this study, colorless and transparent bio-based films were successfully cast using a solution containing a mixture of arabinogalactan (AG) and poly (vinyl alcohol) (PVA). Vanillin was incorporated into the mixture to endow the films with UV-shielding, antioxidant, and antibacterial properties. The morphological, physical, antioxidant, and antibacterial properties of the blend films were then characterized. At an AG:PVA weight ratio of 1:3, and the vanillin content was 0.15 %, the tensile strength of the AG/PVA/Vanillin (APV) films reached ~28 MPa, while their elongation at break reached ~475 %. The addition of vanillin significantly affected the antioxidant and antibacterial properties of the blend films, which exhibited superb UV barrier capacity. The APV films exhibited extremely low oxygen transmittance, delaying the onset of mold/rot in strawberries and reducing their weight loss. Because of the heat sealability of the blend films, they can be used for encapsulating various substances, such as concentrated laundry liquid. Moreover, the blend films were recyclable and biodegradable. Thus, these films have great potential for applications that require sustainable packaging.

Recent advances in dietary polysaccharides from Allium species: Preparation, characterization, and bioactivity

Allium plants, including garlic, onions, shallots, and leeks, belong to the Alliaceae family and are utilized as vegetable, medicinal, and ornamental plants. These plants are consumed both raw and cooked and are noted in traditional medicine for their antibacterial, antitumor, and diuretic properties. Allium plants are a rich source of polyphenols, organosulfur compounds, flavonoids, alkaloids, and polysaccharides, which contribute to their health benefits. As consumer interest in the association between diet and health grows, there is an increasing market demand for foods that promote health, particularly those rich in dietary fiber or non-starch polysaccharides. Allium polysaccharides (APS) have molecular weights of 1 × 103-1 × 106 Da containing small amounts of pectin, glucofructan, or glycoproteins and large amounts of fructans. APS, despite its complex structure, is one of the principal active components of Allium plants but is often overlooked, which restricts its practical application. This paper provides a comprehensive overview of the extraction and purification, structural and functional characteristics, bioactivities, structure-function relationships, and chemical modifications of APS, as well as the effects of APS processing and storage. Additionally, this paper outlines future research directions for APS, which will inform its development and application in the food, pharmaceutical, and cosmetic industries.

Progress of plant-derived non-starch polysaccharides and their challenges and applications in future foods

The development of future food is devoted not only to obtaining a sustainable food supply but also to providing high-quality foods for humans. Plant-derived non-starch polysaccharides (PNPs) are widely available, biocompatible, and nontoxic and have been largely applied to the food industry owing to their mechanical properties and biological activities. PNPs are considered excellent biomaterials and food ingredients contributing to future food development. However, a comprehensive review of the potential applications of PNPs in future food has not been reported. This review summarized the physicochemical and biological activities of PNPs and then discussed the structure-activity relationships of PNPs. Latest studies of PNPs on future foods including cell-cultured meat, food for special medical purposes (FSMPs), and three-dimensional-printed foods were reviewed. The challenges and prospects of PNPs applied to future food were critically proposed. PNPs with strong thermal stability are considered good thickeners, emulsifiers, and gelatinizers that greatly improve the processing adaptability of foods. The mechanical properties of PNPs and decellularized plant-based PNPs make them desirable scaffolds for cultured meat manufacturing. In addition, the biological activities of PNPs exhibit multiple health-promoting effects; therefore, PNPs can act as food ingredients producing FSMP to promote human health. Three-dimensional printing technology enhances food structures and biological activities of functional foods, which is in favor of expanding the application scopes of PNPs in future food. PNPs are promising in future food manufacturing, and more efforts need to be made to realize their commercial applications.

Isolation, structural, biological activity and application of Gleditsia species seeds galactomannans

Gleditsia fruits have been known as a valuable traditional Chinese herb for tens of centuries. Previous studies showed that the galactomannans are considered as one of the major bioactive components in Gleditsia fruits seeds (GSGs). Here, we systematically review the major studies of GSGs in recent years to promote their better understanding. The extraction methods of GSGs mainly include hot water extraction, microwave-assisted extraction, ultrasonic extraction, acid extraction, and alkali extraction. The analysis revealed that GGSs exhibited in the form of semi-flexible coils, and its molecular weight ranged from 0.018 × 103 to 2.778 × 103 KDa. GSGs are composed of various monosaccharide constituents such as mannose, galactose, glucose, and arabinose. In terms of pharmacological effects, GSGs exhibit excellent activity in antioxidation, hypoglycemic, hypolipidemic, anti-inflammation. Moreover, GSGs have excellent bioavailability, biocompatibility, and biodegradability, which make them used in food additives, food packaging, pharmaceutical field, industry and agriculture. Of cause, the shortcomings of the current research and the potential development and future research are also highlighted. We believe our work provides comprehensive knowledge and underpinnings for further research and development of GSGs.

Nanosecond-pulsed plasma protects against bacterial fruit blotch and promotes melon seedling growth

BACKGROUND

Bacterial fruit blotch (BFB), known as the 'cancer' of cucurbits, is a seed-borne disease of melons caused by Acidovorax citrulli. Traditional chemical treatments for BFB are ineffective and adversely affect the environment. Using dielectric barrier discharge (DBD) nanosecond-pulsed plasma technology, melon seeds were treated to promote germination and growth and to control BFB.

RESULTS

Based on the evaluation parameters of seed germination, seedling growth, leaf yellowing and bacterial infection after seed plasma treatments, 9 min at 20 kV was selected as the optimal plasma discharge parameter. In this study, seedling growth was significantly improved after treating melon seeds carrying A. citrulli using this discharge parameter. The number of first true leaves measured on the eighth day was 2.3 times higher and the disease index was reduced by 60.5% compared to the control group. Attenuated total reflectance-Fourier transform infrared measurements show that plasma treatments penetrate the seed coat and denature polysaccharides and proteins in the seed kernel, affecting their growth and sterilization properties.

CONCLUSION

Pre-sowing treatment of melon seeds carrying A. citrulli using nanosecond-pulsed plasma technology can effectively control seedling BFB disease and promote melon seedling growth by optimizing DBD parameters. © 2024 Society of Chemical Industry.

Improvement of antibacterial activity of polysaccharides via chemical modification: A review

Antibiotic residue and bacterial resistance induced by antibiotic abuse have seriously threatened food safety and human healthiness. Thus, the development and application of safe, high-efficiency, and environmentally friendly antibiotic alternatives are urgently necessary. Apart from antitumor, antivirus, anti-inflammatory, gut microbiota regulation, immunity improvement, and growth promotion activities, polysaccharides also have antibacterial activity, but such activity is relatively low, which cannot satisfy the requirements of food preservation, clinical sterilization, livestock feeding, and agricultural cultivation. Chemical modification not only provides polysaccharides with better antibacterial activity, but also promotes easy operation and large-scale production. Herein, the enhancement of the antibacterial activity of polysaccharides via acetylation, sulfation, phosphorylation, carboxymethylation, selenation, amination, acid graft, and other chemical modifications is reviewed. Meanwhile, a new trend on the application of loading chemically modified polysaccharides into nanostructures is discussed. Furthermore, possible limitations and future recommendations for the development and application of chemically modified polysaccharides with better antibacterial activity are suggested.

Insights into the potential dual-antibacterial mechanism of Kelisha capsule on Escherichia coli

Traditional Chinese medicine (TCM), AYURVEDA and Indian medicine are essential in disease prevention and treatment. Kelisha capsule (KLSC), a TCM formula listed in the Chinese Pharmacopoeia, has been clinically proven to possess potent antibacterial properties. However, the precise antimicrobial mechanism of KLSC remained unknown. This study aimed to elucidate the dual antibacterial mechanism of KLSC using network pharmacology, molecular docking, and experimental validation. By analyzing the growth curve of Escherichia coli (E. coli), it was observed that KLSC significantly inhibited its growth, showcasing a remarkable antibacterial effect. Furthermore, SEM and TEM analysis revealed that KLSC damaged the cell wall and membrane of E. coli, resulting in cytoplasmic leakage, bacterial death, and the exertion of antibacterial effects. The network pharmacology analysis revealed that KLSC exhibited an effect on E. coli ATP synthase, thereby influencing the energy metabolism process. The molecular docking outcomes provided evidence that the active compounds of KLSC could effectively bind to the ATP synthase subunit. Subsequently, experimental findings substantiated that KLSC effectively suppressed the activity of ATP synthase in E. coli and consequently decreased the ATP content. This study highlighted the dual antibacterial mechanism of KLSC, emphasizing its effects on cell structure and energy metabolism, suggesting its potential as a natural antibacterial agent for E. coli-related infections. These findings offered new insights into exploring the antibacterial mechanisms of TCM by focusing on the energy metabolism process.

Effects of UV/H2O2 Degradation on the Physicochemical and Antibacterial Properties of Fucoidan

The applications of fucoidan in the food industry were limited due to its high molecular weight and low solubility. Moderate degradation was required to depolymerize fucoidan. A few studies have reported that fucoidan has potential antibacterial activity, but its antibacterial mechanism needs further investigation. In this study, the degraded fucoidans were obtained after ultraviolet/hydrogen peroxide treatment (UV/H2O2) at different times. Their physicochemical properties and antibacterial activities against Staphylococcus aureus and Escherichia coli were investigated. The results showed that the average molecular weights of degraded fucoidans were significantly decreased (up to 22.04 times). They were mainly composed of fucose, galactose, and some glucuronic acid. Fucoidan degraded for 90 min (DFuc-90) showed the strongest antibacterial activities against Staphylococcus aureus and Escherichia coli, with inhibition zones of 27.70 + 0.84 mm and 9.25 + 0.61 mm, respectively. The minimum inhibitory concentrations (MIC) were 8 mg/mL and 4 mg/mL, respectively. DFuc-90 could inhibit the bacteria by damaging the cell wall, accumulating intracellular reactive oxygen species, reducing adenosine triphosphate synthesis, and inhibiting bacterial metabolic activity. Therefore, UV/H2O2 treatment could effectively degrade fucoidan and enhance its antibacterial activity.

Astragalus polysaccharide: implication for intestinal barrier, anti-inflammation, and animal production

Intestine is responsible for nutrients absorption and plays a key role in defending against various dietary allergens, antigens, toxins, and pathogens. Accumulating evidence reported a critical role of intestine in maintaining animal and human health. Since the use of antibiotics as growth promoters in animal feed has been restricted in many countries, alternatives to antibiotics have been globally investigated, and polysaccharides are considered as environmentally friendly and promising alternatives to improve intestinal health, which has become a research hotspot due to its antibiotic substitution effect. Astragalus polysaccharide (APS), a biological macromolecule, is extracted from astragalus and has been reported to exhibit complex biological activities involved in intestinal barrier integrity maintenance, intestinal microbiota regulation, short-chain fatty acids (SCFAs) production, and immune response regulation, which are critical for intestine health. The biological activity of APS is related to its chemical structure. In this review, we outlined the source and structure of APS, highlighted recent findings on the regulation of APS on physical barrier, biochemical barrier, immunological barrier, and immune response as well as the latest progress of APS as an antibiotic substitute in animal production. We hope this review could provide scientific basis and new insights for the application of APS in nutrition, clinical medicine and health by understanding particular effects of APS on intestine health, anti-inflammation, and animal production.

Two novel polysaccharides from Huangshui: Purification, structure, and bioactivities

In this study, the novel polysaccharides named HSP-0 M and HSP-0.1 M were successfully purified from Huangshui (HS), and their structural properties and bioactivities were investigated. Structural analysis revealed that HSP-0 M had a molecular weight of 493.87 kDa and was composed of arabinose, galactose, glucose, xylose, and mannose in a molar ratio of 1.48:1.09:26.52:1.33:1.00. On the other hand, HSP-0.1 M was made up of fructose, arabinose, galactose, glucose, xylose, mannose, ribose, galacturonic acid and glucuronic acid in a ratio of 2.67:26.00:29.10:36.83:16.22:30.53:1.00:1.43:3.64 with a molecular weight of 157.6 kDa. Methylated and 2D NMR analyses indicated that T-Glcp-(1 → 4)-Glcp-(1 → 2)-Glcp-(1 → 3)-Glcp was the primary chain of HSP-0 M, and the backbone of HSP-0.1 M was made up of →3)-Galp-(1 → 6)-Manp-(1 → 3)-Glcp-(1 → 6)-Glcp-(1 → 2)-Manp-(1 → 6)-Glcp-(1 → 3)-Galp. Morphological research showed that both polysaccharides were homogeneous as well as exhibit a web-like structure and an irregular lamellar structure. Furthermore, HSP-0 M demonstrated the capacity to safeguard Lactococcus lactis from damage caused by low temperatures and freeze-drying, while HSP-0.1 M exhibited noteworthy antioxidant activity. These results established a theoretical foundation for the applications of HSPs in food products, cosmetics, and medicines.

Ultrasound-assisted complex enzyme extraction, structural characterization, and biological activity of polysaccharides from Ligustrum robustum

Ligustrum robustum is one of the traditional teas in China with a long history of drinking and medicinal use. Through Response surface optimization, the yield of polysaccharides extracted by ultrasonic-assisted complex enzyme (UAE-EN) method was increased to 14.10 ± 0.56 %. Neutral homogeneous polysaccharide (LRNP) and acidic homogeneous polysaccharide (LRAP-1, LRAP-2, LRAP-3) from L. robustum were purified. The molecular weights of them were 5894, 4256, 4621 and 3915 Da. LRNP was composed of glucose (Glc), galactose (Gal), arabinose (Ara) with molar percentage of 24.97, 42.38 and 30.80. Structure analysis revealed that the backbone of LRNP consisted of 1,5-linked α-Araf, 1,4-linked β-Galp, 1,6-linked β-Galp, and 1,4-linked β-Glcp with the branches of 1,2-linked α-Araf, 1,3-linked α-Araf, 1,3-linked β-Glcp and 1,6-linked β-Galp residues, some terminal residues of α-Araf, β-Glcp and α-Galp were also included. In vitro experiments showed that the four polysaccharides possessed excellent antioxidant, antitumor and hypoglycemic activities. LRNP possessed the protective effect against oxidative stress. The studies provide a basis for further exploitation of L. robustum.

Preparation and adjuvanticity against PCV2 of Viola philippica polysaccharide loaded in Chitosan-Gold nanoparticle

The present Porcine circovirus type 2 virus (PCV2) vaccine adjuvants suffer from numerous limitations, such as adverse effects, deficient cell-mediated immune responses, and inadequate antibody production. In this study, we explored the potential of a novel nanoparticle (CS-Au NPs) based on gold nanoparticles (Au NPs) and chitosan (CS) that modified Viola philippica polysaccharide (VPP) as efficient adjuvants for PCV2 vaccine. The characterization demonstrated that CS-Au-VPP NPs had a mean particle size of 507.42 nm and a zeta potential value of -21.93 mV. CS-Au-VPP NPs also exhibited good dispersion and a stable structure, which did not alter the polysaccharide properties. Additionally, the CS-Au-VPP NPs showed easy absorption and utilization by the organism. To investigate their immune-enhancing potential, mice were immunized with a mixture of CS-Au-VPP NPs and PCV2 vaccine. The evaluation of relevant immunological indicators, including specific IgG antibodies and their subclasses, cytokines, and T cell subpopulations, confirmed their immune-boosting effects. The in vivo experiments revealed that the medium-dose CS-Au-VPP NPs significantly elevated the levels of specific IgG antibodies and their subclasses, cytokines, and T cell subpopulations in PCV2-immunized mice. These findings suggest that CS-Au-VPP NPs can serve as a promising vaccine adjuvant due to their stable structure and immunoenhancement capabilities.

Updated Progress on Polysaccharides with Anti-Diabetic Effects through the Regulation of Gut Microbiota: Sources, Mechanisms, and Structure-Activity Relationships

Diabetes mellitus (DM) is a common chronic metabolic disease worldwide. The disturbance of the gut microbiota has a complex influence on the development of DM. Polysaccharides are one type of the most important natural components with anti-diabetic effects. Gut microbiota can participate in the fermentation of polysaccharides, and through this, polysaccharides regulate the gut microbiota and improve DM. This review begins by a summary of the sources, anti-diabetic effects and the gut microbiota regulation functions of natural polysaccharides. Then, the mechanisms of polysaccharides in regulating the gut microbiota to exert anti-diabetic effects and the structure-activity relationship are summarized. It is found that polysaccharides from plants, fungi, and marine organisms show great hypoglycemic activities and the gut microbiota regulation functions. The mechanisms mainly include repairing the gut burrier, reshaping gut microbiota composition, changing the metabolites, regulating anti-inflammatory activity and immune function, and regulating the signal pathways. Structural characteristics of polysaccharides, such as monosaccharide composition, molecular weight, and type of glycosidic linkage, show great influence on the anti-diabetic activity of polysaccharides. This review provides a reference for the exploration and development of the anti-diabetic effects of polysaccharides.

Plant polysaccharides extracted by high pressure: A review on yields, physicochemical, structure properties, and bioactivities

Polysaccharides are biologically essential macromolecules, widely exist in plants, which are used in food, medicine, bioactives' encapsulation, targeted delivery and other fields. Suitable extraction technology can not only improve the yield, but also regulate the physicochemical, improve the functional property, and is the basis for the research and application of polysaccharide. High pressure (HP) extraction (HPE) induces the breakage of raw material cells and tissues through rapid changes in pressure, increases extraction yield, reduces extraction time, and modifies structure of polysaccharides. However, thus far, literature review on the mechanism of extraction, improved yield and modified structure of HPE polysaccharide is lacking. Therefore, the present work reviews the mechanism of HPE polysaccharide, increasing extraction yield, regulating physicochemical and functional properties, modifying structure and improving activity. This review contributes to a full understanding of the HPE or development of polysaccharide production and modification methods and promotes the application of HP technology in polysaccharide production.

Extraction, purification, structural features, modifications, bioactivities, structure-activity relationships, and applications of polysaccharides from garlic: A review

Garlic is a common vegetable and spice in people's daily diets, in which garlic polysaccharide (GP) is one of the most important active components with a variety of benefits, such as antioxidant, immune-enhancing, anti-inflammatory, liver-protective and bowel-regulating properties. >20 types of GPs, mainly crude polysaccharides, have been identified. However, the exact chemical composition of GPs or the mechanism underlying their pharmacological activity is still not fully understood. The extraction and purification methods of GPs are compared in this review while providing detailed information on their structural features, identification methods, major biological activities, mechanisms of actions, structural modifications, structure-activity relationships as well as potential applications. Finally, the limitations of GP research and future issues that need to be addressed are discussed in this review. GPs are widely recognized as substances with great potential in the pharmaceutical and food industries. Therefore, this review aims to provide a comprehensive summary of the latest research progresses in the field of GPs, together with scientific insights and a theoretical support for the development of GPs in research and industrialization.

Extracellular matrix-mimetic immunomodulatory fibrous scaffold based on a peony stamens polysaccharide for accelerated wound healing

Re-establishment of the extracellular matrix (ECM) in wound tissue is critical for activating endogenous tissue repair. In this study, we designed an ECM-like scaffold material using plant polysaccharides and assessed its efficacy through in vitro and in vivo experiments. The scaffold accelerates wound healing by regulating inflammatory responses and accelerating tissue regeneration. Briefly, we isolated two polysaccharides of varying molecular weights from peony stamens. One of the polysaccharides exhibits potent immunomodulatory and tissue regeneration activities. We further prepared electrospinning materials containing this polysaccharide. In vitro investigations have demonstrated the polysaccharide's ability to modulate immune responses by targeting TLR receptors. In vivo experiments utilizing a scaffold composed of this polysaccharide showed accelerated healing of full-thickness skin wounds in mice, promoting rapid tissue regeneration. In conclusion, our study shows that this scaffold can mobilize the endogenous regenerative capacity of tissues to accelerate repair by mimicking the characteristics of ECM. The overall study has implications for the design of new, effective, and safer tissue regeneration strategies.

Current situation, trend, and prospects of research on functional components from by-products of baijiu production: A review

In the present scenario marked by energy source shortages and escalating concerns regarding carbon dioxide emissions, there is a growing emphasis on the optimal utilization of biomass resources. Baijiu, as the Chinese national spirit, boasts remarkably high sales volumes annually. However, the production of baijiu yields various by-products, including solid residues (Jiuzao), liquid wastewater (Huangshui and waste alcohol), and gaseous waste. Recent years have witnessed dedicated research aimed at exploring the composition and potential applications of these by-products, seeking sustainable development and comprehensive resource utilization. This review systematically summarizes recent research, shedding light on both the baijiu brewing process and the bioactive compounds present baijiu production by-products (BPBPs). The primary focus lies in elucidating the potential extraction methods and applications of BPBPs, offering a practical approach to comprehensive utilization of by-products in functional food, medicine, cosmetic, and packaging fields. These applications not only contribute to enhancing production efficiency and mitigating environmental pollution, but also introduce innovative concepts for the sustainable advancement of associated industries. Future research avenues may include more in-depth compositional analysis, the development of utilization technologies, and the promotion of potential industrialization.

Structure, Physicochemical Properties and Biological Activity of Lipopolysaccharide from the Rhizospheric Bacterium Ochrobactrum quorumnocens T1Kr02, Containing d-Fucose Residues

Lipopolysaccharides (LPSs) are major components of the outer membranes of Gram-negative bacteria. In this work, the structure of the O-polysaccharide of Ochrobactrum quorumnocens T1Kr02 was identified by nuclear magnetic resonance (NMR), and the physical-chemical properties and biological activity of LPS were also investigated. The NMR analysis showed that the O-polysaccharide has the following structure: →2)-β-d-Fucf-(1→3)-β-d-Fucp-(1→. The structure of the periplasmic glucan coextracted with LPS was established by NMR spectroscopy and chemical methods: →2)-β-d-Glcp-(1→. Non-stoichiometric modifications were identified in both polysaccharides: 50% of d-fucofuranose residues at position 3 were O-acetylated, and 15% of d-Glcp residues at position 6 were linked with succinate. This is the first report of a polysaccharide containing both d-fucopyranose and d-fucofuranose residues. The fatty acid analysis of the LPS showed the prevalence of 3-hydroxytetradecanoic, hexadecenoic, octadecenoic, lactobacillic, and 27-hydroxyoctacosanoic acids. The dynamic light scattering demonstrated that LPS (in an aqueous solution) formed supramolecular particles with a size of 72.2 nm and a zeta-potential of -21.5 mV. The LPS solution (10 mkg/mL) promoted the growth of potato microplants under in vitro conditions. Thus, LPS of O. quorumnocens T1Kr02 can be recommended as a promoter for plants and as a source of biotechnological production of d-fucose.

Effects of different extraction methods on the physico-chemical characteristics and biological activities of polysaccharides from Clitocybe squamulosa

This study comparatively evaluated the effects of the commonly used six extraction methods (acidic, alkaline, enzymatic, ultrasonic, high-pressure, and microwave) on the physico-chemical properties, processing characteristics, and biological activities of polysaccharides from Clitocybe squamulosa (CSFPs). The results show that polysaccharides extracted using an enzyme-assisted extraction method has a relatively high extraction yield (4.46 ± 1.62 %) and carbohydrate content (70.79 ± 6.25 %) compared with others. Furthermore, CSFPs were all composed of glucose, galactose, mannose, xylose, and glucosamine hydrochloride. Only ultrasonic-assisted extraction of polysaccharides (CSFP-U) has a triple helix chain conformation. Scanning electron microscopy (SEM) revealed significant differences in the microstructure of polysaccharides prepared using different methods. Besides that, the polysaccharides prepared by alkali extraction (CSFP-B) and high-pressure assisted extraction (CSFP-H) have good water (2.86 ± 0.29 g/g and 3.15 ± 0.29 g/g) and oil (8.13 ± 0.32 g/g and 7.97 ± 0.04 g/g) holding properties. The rheological behavior demonstrated that CSFPs solutions were typical non-Newtonian fluid. Apart from this, the antioxidant capacity (clearing DPPH (IC50 = 0.29) and ABTS free radicals (IC50 = 0.19), total reduction ability (IC50 = 3.02)) of polysaccharides prepared by the microwave-assisted extraction (CSFP-M) method was significantly higher than that of other extraction methods. By contrast, the polysaccharide prepared by acid extraction (CSFP-A) has the optimum binding capacity (bile acid salt (71.30 ± 6.78 %) and cholesterol (57.07 ± 3.26 mg/g)). The antibacterial activity of CSFPs was positively correlated with their concentration. Thus, the research results can provide a theoretical basis for the development and utilization of polysaccharides from C. squamulosa.

Adopting the "Missile boats-Aircraft carrier" strategy via human-contact friendly oxidized starch to achieve rapid-sustainably antibacterial paperboards

Polysaccharide-based antibacterial agents have received tremendous attention for the facile fabrication, low toxicity, and high compatibility with carbohydrate polymers. However, the antimicrobial mechanism, activity, and cytotoxicity for human-contact paperboards of oxidized starch (OST) with high carboxyl content, has not been explored. Herein, OST-27- 75 with 27- 75 wt% carboxyl contents were fabricated by H2O2 and coated on paperboards. Strikingly, OST-55 coating layer (16 g/m2) did not exfoliate from paperboard and possessed the rapid-sustainable antibacterial performance against Staphylococcus aureus and Escherichia coli. The soluble and insoluble components of OST-55 (OST55-S: OST55-IS mass ratio = 1: 2.1) presented different antimicrobial features and herein they were characterized by GC-MS, FT-IR, H-NMR, XRD, bacteriostatic activities, biofilm formation inhibition and intracellular constituent leakage to survey the antibacterial mechanism. The results revealed OST55-S displayed an amorphous structure and possessed superior antibacterial activity against S. aureus (MIC = 4 mg/mL) and E. coli (MIC = 8 mg/mL). Distinctively, OST55-S could rapidly ionize [H+] like "missile boats" from small molecule saccharides, while OST55-IS polyelectrolyte could continuously and slowly release for [H+] like an "aircraft carrier" to inhibit biofilm formation and disrupt cell structure. Eventually, the "Missile boats-Aircraft carrier" strategy provided a green methodology to fabricate polymeric antibacterial agents and expanded the use of cellulose-based materials.

Extraction, purification, characteristics, bioactivities, prospects, and toxicity of Lilium spp. polysaccharides

The genus Lilium has been widely used worldwide as a food and medicinal ingredient in East Asia for over 2000 years due to its higher nutritional and medicinal value. Polysaccharide is the most important bioactive ingredient in Lilium spp. and has various health benefits. Recently, Lilium spp. polysaccharides (LSPs) have attracted significant attention from industries and researchers due to their various biological properties, such as antioxidant, immunomodulatory, antitumor, antibacterial, hypoglycaemic, and anti-radiation. However, the development and utilization of LSP-based functional biomaterials and medicines are limited by a lack of comprehensive understanding regarding the structure-activity relationships (SARs), industrial applications, and safety of LSPs. This review provides an inclusive overview of the extraction, purification, structural features, bioactivities, and mechanisms of LSPs. SARs, applications, toxicities, and influences of structural modifications on bioactivities are also highlighted, and the potential development and future study direction are scrutinized. This article aims to offer a complete understanding of LSPs and provide a foundation for further research and application of LSPs as therapeutic agents and multifunctional biomaterials.

Plantago asiatica L. polysaccharides: Physiochemical properties, structural characteristics, biological activity and application prospects: A review

Plantago asiatica L. (PAL), a traditional herb, has been used in East Asia for thousands of years. In recent years, polysaccharides extracted from PAL have garnered increased attention due to their outstanding pharmacological and biological properties. Previous research has established that PAL-derived polysaccharides exhibit antioxidant, anti-inflammatory, antidiabetic, antitumor, antimicrobial, immune-regulatory, intestinal health-promoting, antiviral, and other effects. Nevertheless, a comprehensive summary of the research related to Plantago asiatica L. polysaccharides (PALP) has not been reported to date. In this paper, we review the methods for isolation and purification, physiochemical properties, structural features, and biological activities of PALP. To provide a foundation for research and application in the fields of medicine and food, this review also outlines the future development prospects of plantain polysaccharides.

Natural antimicrobials from plants: Recent advances and future prospects

Plant-based antimicrobial substances have emerged as promising alternatives to conventional antibiotics and preservatives. Although many review studies have been done in this field, many of these reviews solely focus on specific compounds from particular perspectives. This paper aims to provide a comprehensive review on the various types of plant-based antimicrobial substances, the extraction and purification processes, as well as the application and safety issues. Combining different natural plant-derived substances shows promise in enhancing antimicrobial activities. Moreover, despite the existence of various methods (e.g., microwave-assisted extraction, supercritical fluid extraction) to extract and purify antimicrobial substances, isolating pure compounds remains a laborious process. Sustainability issues should also be considered when developing extraction methods. Additionally, the extraction process generates a significant amount of plant waste, necessitating proper utilization to ensure economic viability. Lastly, not all plant-derived substances are safe, and further research is needed to investigate their toxicity before widespread application.

Construction of asymmetric dual-layer polysaccharide-based porous structure on multiple sources for potential application in biomedicine

Biomedical materials can produce high efficiency and special behavior with an integrated internal structure. It is possible that changing the structure of biomedical materials could extend and promote the application of eco-friendly and multifunctional biomaterials. However, the instantaneous formation of complex structures between tannic acid (TA) and polysaccharides is disrupted, and the reconstruction of the new porous structure becomes a key issue. Here, we present an innovative one-step forming method for an asymmetric dual-layer porous structure of carboxymethyl chitosan (CC)/sodium alginate (SA)/TA, which can be utilized in various biomedical applications. Even after 6 months of storage, it still demonstrates a range of desirable properties including tailorable performance, efficient antibacterial activity, ultrarapid antioxidant activity, low differential blood clotting index and cytotoxicity. This suggests its potential for regulating and controlling wound bleeding, providing flexible possibilities for potential applications in biomedicine.

Extraction of Ampelopsis japonica polysaccharides using p-toluenesulfonic acid assisted n-butanol three-phase partitioning: Physicochemical, rheological characterization and antioxidant activity

Polysaccharides as the biopolymers are showing various structural and modulatory functions. Effective separation of carbohydrate structures is essential to understanding their function. In this study, we choose an efficient organic acid in combination with recyclable organic solvent three-phase partitioning technology for the simultaneous extraction of polysaccharides from Ampelopsis japonica (AJPs) to ensure the integrity of linear and branched polysaccharide. The monosaccharide composition, glycosidic linkage information, structural and physicochemical analyses and associations with antioxidant activities were extensively analyzed. Synergistic extraction was compared with the conventional hot water extraction method and the results showed that AJPs-HNP exhibited better elastic properties and excellent antioxidant activity. Correlation analysis confirmed that the antioxidant activity of AJPs was significantly correlated with relative molecular weight, uronic acid content and terminal glycoside linkage molar ratios. The collaborative processing has significantly improved the utilization potential of AJPs and provides a sound theoretical foundation for the effective extraction and separation of polysaccharides. Overall, this work provides systematic and comprehensive scientific information on the physicochemical, rheological and antioxidant properties of AJPs, revealing their potential as natural antioxidants in the functional food and pharmaceutical industries.

Mechanisms and structure-activity relationships of polysaccharides in the intervention of Alzheimer's disease: A review

Alzheimer's disease (AD) is a complex neurodegenerative disease. Despite several decades of research, the development of effective treatments and responses for Alzheimer's disease remains elusive. The utilization of polysaccharides for Alzheimer's disease became more popular due to their beneficial characteristics, notably their multi-target activity and low toxicity. This review mainly focuses on the researches of recent 5 years in the regulation of AD by naturally derived polysaccharides, systematically lists the possible intervention pathways of polysaccharides from different mechanisms, and explores the structure-activity relationship between polysaccharide structural activities, so as to provide references for the intervention and treatment of AD by polysaccharides.

Characterization of a novel exopolysaccharide from Acinetobacter rhizosphaerae with ability to enhance the salt stress resistance of rice seedlings

We here describe the isolation of a novel exopolysaccharide from Acinetobacter rhizosphaerae, named ArEPS. The structure of ArEPS was characterized by analysis of the monosaccharide composition, molecular weight, infrared spectrum, methylation, and nuclear magnetic resonance spectrum. ArEPS was found to be an acidic heteropolysaccharide composed of glucose, galactose, galacturonic acid, glucuronic acid, mannose, and glucosamine; the molecular weight was 1533 kDa. Structural analysis showed that the main-chain structure of ArEPS predominantly comprised 1,3,6-β-Glcp, 1,3,4-α-Galp, 1,2-β-Glcp, 1,4-β-GlcpA, 1,4-β-GalpA, and the side-chain structure comprised 1,6-β-Glcp, 1,3-β-Galp, 1-α-Glcp, 1-β-Galp, 1-α-Manp, 1,4,6-α-Glcp, 1,2,4-β-Glcp, 1,2,3-β-Glcp, and 1,3-β-GlcpN. ArEPS significantly enhanced the tolerance of rice seedlings to salt stress. Specifically, plant height, fresh weight, chlorophyll content, and the K+/Na+ ratio increased by 51 %, 63 %, 29 %, and 162 %, respectively, and the malondialdehyde content was reduced by 45 % after treatment with 100 mg/kg ArEPS compared to treatment with 100 mM NaCl. Finally, based on the quadratic regression between fresh weight and ArEPS addition, the optimal ArEPS addition level was estimated to be 135.12 mg/kg. These results indicate the prospects of ArEPS application in agriculture.

Research progress of natural plant polysaccharides inhibiting inflammatory signaling pathways and regulating intestinal flora and metabolism to protect inflammatory bowel disease

Natural plant polysaccharides are macromolecular substances with a wide range of biological activities. They have a wide range of biological activities, especially play an important role in the treatment of inflammatory bowel disease. The molecular weight of polysaccharides, the composition of monosaccharides and the connection of glycosidic bonds will affect the therapeutic effect on inflammatory bowel disease. Traditional Chinese medicine plant polysaccharides and various types of plant polysaccharides reduce the levels of inflammatory cytokines IL-1β, IL-6, IL-8 and IL-17, increase the level of anti-inflammatory factor IL-10, regulate NF-κB signaling pathway, and NLRP3 inflammasome to relieve colitis. At the same time, they can play a protective role by regulating the balance of intestinal flora in mice with colitis and increasing the abundance of probiotics to promote the metabolism of polysaccharide metabolites SCFAs. This review summarizes the research on the treatment of inflammatory bowel disease by many natural plant polysaccharides, and provides a theoretical basis for the later treatment of polysaccharides on inflammatory bowel disease.

Effect of hydrophobic property on antibacterial activities of green tea polysaccharide conjugates against Escherichia coli

We previously found that green tea polysaccharide conjugates (gTPCs) have antibacterial activity against Escherichia coli. In this study, the effect of hydrophobic property on the antibacterial activities of gTPCs was evaluated to elucidate their property-activity relationship. Three gTPCs (gTPCs-5 h, gTPCs-12 h and gTPCs-24 h) were extracted from green tea with the ethanol precipitation time of 5 h, 12 h and 24 h, respectively. These three gTPCs did not differ significantly in terms of molecular weight distribution, amino acids composition and zeta potentials. Fourier transform infrared spectroscopy results revealed that gTPCs-5 h and gTPCs-12 h processed more hydrogen bonds than gTPCs-24 h. The surface hydrophobicity and contact angle of gTPCs-5 h were larger than that of gTPCs-12 h and gTPCs-24 h. The antibacterial activity of gTPCs against E. coli decreased in the order of gTPCs-5 h > gTPCs-12 h > gTPCs-24 h. There wasn't significant difference among the zeta potentials of E. coli treated by gTPCs-5 h, gTPCs-12 h and gTPCs-24 h, but the bacterial contact angles of E. coli treated by gTPCs-5 h were higher compared with those of the other two gTPCs. Furthermore, gTPCs-5 h exhibited higher activity to decrease bacterial membrane proteins, and increase bacterial membrane permeability than the other two gTPCs. In conclusion, gTPCs with higher hydrophobicity property exhibited stronger antibacterial activity against E. coli.

Antibacterial activity of a polysaccharide isolated from Artemisia argyi leaf against Staphylococcus aureus and mechanism investigation

Abuse of antibiotics has led to excessive amounts of antibiotic residues in food and environment, thus enhancing pathogenic bacterium resistance and threatening human health. Therefore, searching and developing safe and green antibiotic alternatives are necessary. In this study, an Artemisia argyi leaf polysaccharide (AALP) fraction was extracted and analyzed. Chemical composition analysis showed that the carbohydrate, uronic acid, protein, and polyphenol content in AALP were 68.3 % ± 4.13 %, 9.4 % ± 0.86 %, 1.79 % ± 0.27 %, and 0.16 % ± 0.035 %, respectively. Chromatographic results suggested that AALP contained rhamnose, arabinose, glucosamine, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid in a molar ratio of 9.26, 1.35, 1.18, 3.04, 48.51, 2.33, 31.26, 3.93, and 9.08; the weight average molecular weight, number average molecular weight, and polydispersity of AALP were 5.41 kDa, 4.63 kDa, and 1.168, respectively. Fourier transform infrared spectroscopy indicated that AALP constituted the polysaccharide-specific groups of CH, CO, and OH. Meanwhile, AALP showed a dose-dependent inhibitory effect on Staphylococcus aureus in the inhibition zone assay, and the minimal inhibitory concentration was 1.25 mg/mL. Furthermore, AALP disrupted the cell wall, depolarized the inner membrane potential, and inhibited the activities of succinate dehydrogenase and malate dehydrogenase in S. aureus.

Pectin from Citrus unshiu Marc. Alleviates Glucose and Lipid Metabolism by Regulating the Gut Microbiota and Metabolites

The effects of pectin from Citrus unshiu Marc. on glycolipid metabolism, the morphologies of the pancreas and epididymal fat, the gut microbiota, and the metabolites of short-chain fatty acids (SCFAs) in db/db mice were investigated in this study. The results indicated that pectin reduced the levels of fasting blood glucose, glycated serum protein, triglycerides, total cholesterol, and low-density lipoprotein cholesterol while increasing the levels of high-density lipoprotein cholesterol. Meanwhile, pectin could improve the morphology of islet cells and inhibit the hypertrophy of adipocytes. Additionally, pectin not only regulated the intestinal flora dysbiosis in db/db mice, as shown by the increasing proportion of Firmicutes/Bacteroidetes and the relative abundance of Ligilactobacillus, Lactobacillus, and Limosilactobacillus, but also remedied the metabolic disorder of SCFAs in db/db mice. These results suggest that pectin could promote glucose and lipid metabolism by regulating the intestinal flora with changes in SCFA profile. This study proves that pectin might serve as a new prebiotic agent to prevent the disorder of glycolipid metabolism.

Exploring the partial degradation of polysaccharides: Structure, mechanism, bioactivities, and perspectives

Polysaccharides are promising biomolecules with lowtoxicity and diverse bioactivities in food processing and clinical drug development. However, an essential prerequisite for their applications is the fine structure characterization. Due to the complexity of polysaccharide structure, partial degradation is a powerful tool for fine structure analysis, which can effectively provide valid information on the structure of backbone and branching glycosidic fragments of complex polysaccharides. This review aims to conclude current methods of partial degradation employed for polysaccharide structural characterization, discuss the molecular mechanisms, and describe the molecular structure and solution properties of degraded polysaccharides. In addition, the effects of polysaccharide degradation on the conformational relationships between the molecular structure and bioactivities, such as antioxidant, antitumor, and immunomodulatory activities, are also discussed. Finally, we summarize the prospects and current challenges for the partial degradation of polysaccharides. This review will be of great value for the scientific elucidation of polysaccharide fine structures and potential applications.

Control the carcinogenic bacteria with new polysaccharides from agricultural wastes

Agriculture activities industries produce a huge amount of waste every year. Agricultural wastes are a great source of natural polysaccharides characterized by accessibility, biocompatibility, and ease of modification. Finding new safe antibacterial agents has become one of the top priorities of health organizations worldwide. This priority emerged from the antibiotic resistance pathogenic bacteria hazard. Carcinogenic bacteria are one of the most dangerous antibiotic-resistant pathogenic bacteria. This study tries to investigate the antibacterial activity of polysaccharides from some agricultural wastes against carcinogenic bacteria related to gastrointestinal cancers. We determined the antibacterial activity (in terms of minimum inhibitory concentration (MIC)) and the biofilm reduction capacity. We studied the mechanism of the antibacterial activity by determining the effect of the MIC of the extracted polysaccharides on the plasma membrane permeability and the bacterial DNA content. All extracted polysaccharides showed effective antibacterial activity with low MICs ranging from 2 to 20 μg/mL. The barely straw polysaccharides showed the highest MIC (19.844 μg/mL) against Bacteroides fragilis, while the grape bagasse showed the lowest MIC (2.489 μg/mL) against Helicobacter pylori. The extracted polysaccharide showed high antibiofilm activity. Their capacity to reduce the formation of the pathogenic biofilm ranged from 75 to 95%. Regarding the antibacterial mechanism, the extracted polysaccharides showed destructive action on the DNA and the plasma membrane permeability. The bacterial DNA change percent after the treatment with the different polysaccharides ranged from 29% to -58%. The plasma membrane permeability increased by a high percentage, ranging from 92% to 123%. Agricultural waste polysaccharides are a promising antibacterial agent against antibiotic-resistant carcinogenic bacteria.

Polysaccharide-based films: from packaging materials to functional food

A wider application of naturally derived polysaccharides is of great interest as materials for food packaging industry. Biocompatibility and biodegradability of polysaccharide-based films and coatings ally with a shift from application of non-biodegradable petrochemical polymers to the more environmentally friendly ones. Due to a range of inherent features in chemical structure and bioactivity, the polysaccharide materials could bring additional functionality to food packaging. The chelating ability of the polysaccharides provides also their application as carriers of additional active components, such as nanoparticles, essential oils and polyphenols. The improved physicochemical, antibacterial and antioxidant properties of the filled films allows to consider the edible polysaccharide-based films as functional food products. This review is aimed at analysis of evolution of polysaccharide-based food packaging materials from inert one starting from cellophane to recent research works on development of multicomponent polysaccharide-based functional food films and coatings.

Long-term oral administration of burdock fructooligosaccharide alleviates DSS-induced colitis in mice by mediating anti-inflammatory effects and protection of intestinal barrier function

BACKGROUND

Ulcerative colitis, a typical subtype of inflammatory bowel disease, can cause many serious complications. Burdock fructooligosaccharide (BFO), a linear inulin with a purity of 99.439% and a molecular weight of 2345 Da, demonstrates anti-inflammatory and immunomodulatory properties.

METHODS

The Kunming mice were divided into two experimental models: a normal pretreatment model and a colitis experimental model. During the experimental treatment period, we assessed changes in weight and disease activity index (DAI), quantified the intestinal index, and determined myeloperoxidase (MPO) activity and reactive oxide species (ROS) levels in colitis mice. We also photographed colon morphology to investigate alterations in the integrity of the intestinal barrier function. Finally, we performed ELISA and qRT-PCR to evaluate the anti-inflammatory effect of BFO treatment on colitis mice.

RESULT

The long-term oral administration of BFO alone exhibited protective effects by preventing disruption of the intestinal functional structure and increasing the colon index in mice. However, in a dextran sodium sulfate (DSS)-induced colitis mouse model, BFO administration facilitated quick recovery of body weight and effectively reduced the DAI, especially in the BFO-H group (500 mg/kg/day). BFO treatment maintained the integrity of the intestinal barrier by attenuating the crypt distortion and increasing the goblet cells count It restored the DSS-induced colon shortening and reduced the symptoms of colitis. These effects may be attributed to the appropriate concentrations of BFO effectively inhibiting MPO activity, clearing excessive ROS, and relieving spleen abnormalitie. BFO also attenuated the overexpression and excessive secretion of inflammatory cytokines (TNF-α, IL-1β, IL-6, and MCP-1) induced by DSS, reduced intestinal inflammation, and consequently protected the intestinal barrier function.

CONCLUSION

BFO effectively alleviated the symptoms of DSS-induced colitis by mediating anti-inflammatory effects and protecting the intestinal barrier integrity, thereby potentially facilitating the utilization of safer and more efficacious polysaccharides for managing chronic inflammatory diseases.

Process optimization for spray dried Aegle marmelos fruit nanomucilage: Characterization, functional properties, and in vitro antibiofilm activity against food pathogenic microorganisms

Recently, mucilage extraction from plant sources has been remarkably explored due to its potential applications. Several underutilized fruits such as Aegle marmelos are the potential source of mucilage that can be utilized for agri-food-pharma applications. Therefore, in this study, we explored vital functional and antimicrobial properties of Aegle marmelos nanomucilage. Spray drying conditions such as inlet temperature, feed flow, and atomization speed were optimized to assess the influence on yield and moisture content using response surface methodology. In addition, during the optimized spray drying conditions, the maximum mucilage yield was 16.23 % (w/w). The particle size (178.4 ± 5.06 nm) at the nanoscale, polydispersity index (0.432), and zeta potential (-16.4 ± 1.14 mV) confirmed the stability of the nanomucilage. Moreover, the spray-dried nanomucilage powder exhibited high thermal stability (55.70 J) and excellent industrially important techno-functional properties with water-holding capacity (8.01 ± 0.04 g/g), oil-holding capacity (3.43 ± 0.7 g/g), emulsifying capacity (91.50 ± 0.78 %), emulsifying stability (92.65 ± 0.46 %), solubility (89.36 ± 1.69 %), and foaming capacity (16.13 ± 0.41 %). Moreover, the powder showed strong antibiofilm activity against food-pathogenic bacteria, including Escherichia coli (73.52 ± 1.14 %) and Staphylococcus aureus (79.57 ± 1.23 %), with minimum inhibitory concentrations of 3.125 mg/mL and 1.562 mg/mL respectively. Overall, based on the above findings the spray-dried powder of Aegle marmelos fruit nanomucilage could be utilized as a potential functional ingredient in various food products formulations.

Polysaccharide-based antibacterial coating technologies

To tackle antimicrobial resistance, a global threat identified by the United Nations, is a common cause of healthcare-associated infections (HAI) and is responsible for significant costs on healthcare systems, a substantial amount of research has been devoted to developing polysaccharide-based strategies that prevent bacterial attachment and biofilm formation on surfaces. Polysaccharides are essential building blocks for life and an abundant renewable resource that have attracted much attention due to their intrinsic remarkable biological potential antibacterial activities. If converted into efficient antibacterial coatings that could be applied to a broad range of surfaces and applications, polysaccharide-based coatings could have a significant potential global impact. However, the ultimate success of polysaccharide-based antibacterial materials will be determined by their potential for use in manufacturing processes that are scalable, versatile, and affordable. Therefore, in this review we focus on recent advances in polysaccharide-based antibacterial coatings from the perspective of fabrication methods. We first provide an overview of strategies for designing polysaccharide-based antimicrobial formulations and methods to assess the antibacterial properties of coatings. Recent advances on manufacturing polysaccharide-based coatings using some of the most common polysaccharides and fabrication methods are then detailed, followed by a critical comparative overview of associated challenges and opportunities for future developments. STATEMENT OF SIGNIFICANCE: Our review presents a timely perspective by being the first review in the field to focus on advances on polysaccharide-based antibacterial coatings from the perspective of fabrication methods along with an overview of strategies for designing polysaccharide-based antimicrobial formulations, methods to assess the antibacterial properties of coatings as well as a critical comparative overview of associated challenges and opportunities for future developments. Meanwhile this work is specifically targeted at an audience focused on featuring critical information and guidelines for developing polysaccharide-based coatings. Including such a complementary work in the journal could lead to further developments on polysaccharide antibacterial applications.

Application of chromatography in purification and structural analysis of natural polysaccharides: A review

Polysaccharides are widely distributed in natural sources from monocytic microorganisms to higher animals, and are found in a variety of biological activities in recent decades. Natural polysaccharides have the characteristics of large molecular weight, diverse composition, and complex structure, so their purification and structural analysis are difficult issues in research. Chromatography as a powerful separation technique, plays an irreplaceable role in the separation and structural analysis of natural polysaccharides, especially in the purification of polysaccharides, the separation of hydrolysates, and the analysis of monosaccharide composition. The separation mechanisms and application of different chromatographic methods in the studies of polysaccharides were summarized in this review. Moreover, the advantages and drawbacks of various chromatography methods were discussed as well.

Research progress on the prevention and treatment of hyperuricemia by medicinal and edible plants and its bioactive components

Hyperuricemia is another common metabolic disease, which is considered to be closely related to the development of many chronic diseases, in addition to the "three highs." Currently, although drugs show positive therapeutic effects, they have been shown to produce side effects that can damage the body. There is growing evidence that medicinal and edible plants and their bioactive components have a significant effect on hyperuricemia. In this paper, we review common medicinal and edible plants with uric acid-lowering effects and summarize the uric acid-lowering mechanisms of different bioactive components. Specifically, the bioactive components are divided into five categories: flavonoids, phenolic acids, alkaloids, polysaccharides, and saponins. These active substances exhibit positive uric acid-lowering effects by inhibiting uric acid production, promoting uric acid excretion, and improving inflammation. Overall, this review examines the potential role of medicinal and edible plants and their bioactive components as a means of combating hyperuricemia, with the hope of providing some reference value for the treatment of hyperuricemia.

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.

Polysaccharide-Based Stimulus-Responsive Nanomedicines for Combination Cancer Immunotherapy

Cancer immunotherapy is a promising antitumor approach, whereas nontherapeutic side effects, tumor microenvironment (TME) intricacy, and low tumor immunogenicity limit its therapeutic efficacy. In recent years, combination immunotherapy with other therapies has been proven to considerably increase antitumor efficacy. However, achieving codelivery of the drugs to the tumor site remains a major challenge. Stimulus-responsive nanodelivery systems show controlled drug delivery and precise drug release. Polysaccharides, a family of potential biomaterials, are widely used in the development of stimulus-responsive nanomedicines due to their unique physicochemical properties, biocompatibility, and modifiability. Here, the antitumor activity of polysaccharides and several combined immunotherapy strategies (e.g., immunotherapy combined with chemotherapy, photodynamic therapy, or photothermal therapy) are summarized. More importantly, the recent progress of polysaccharide-based stimulus-responsive nanomedicines for combination cancer immunotherapy is discussed, with the focus on construction of nanomedicine, targeted delivery, drug release, and enhanced antitumor effects. Finally, the limitations and application prospects of this new field are discussed.

A novel strategy to enhance photocatalytic killing of foodborne pathogenic bacteria by modification of non-metallic monomeric black phosphorus with Elaeagnus mollis polysaccharides

New antibacterial agents are needed to overcome the challenges of microbial food contamination. In this study, we investigated the potential of Elaeagnus mollis polysaccharide (EMP) to modify black phosphorus (BP) for use as a bactericide for foodborne pathogenic bacteria. The resulting compound (EMP-BP) displayed enhanced stability and activity compared with BP. EMP-BP exhibited an increased antibacterial activity (bactericidal efficiency of 99.999 % after 60 min of light exposure) compared to EMP and BP. Further studies revealed that photocatalytically generated reactive oxygen species (ROS) and active polysaccharides acted collectively on the cell membrane, leading to cell deformation and death. Furthermore, EMP-BP inhibited biofilm formation and reduced expression of virulence factors of Staphylococcus aureus, and material hemolysis and cytotoxicity tests prove that the material had good biocompatibility. In addition, bacteria treated with EMP-BP remained highly sensitive to antibiotics and did not develop significant resistance. In summary, we report an environmentally friendly method for controlling pathogenic foodborne bacteria that is efficient and apparently safe.

Application of carboxymethyl chitosan-based coating in fresh-cut apple preservation: Incorporation of guava leaf flavonoids and their noncovalent interaction study

Carboxymethyl chitosan (CMCS) has antibacterial activity and coating-forming ability. Under the impact of noncovalent interactions, the bioactivity and functionality of CMCS may be positively affected by the coexistence of flavonoids. This study investigated the effect of a CMCS coating incorporated with flavonoids from guava (Psidium guajava L. cv. Carmine) leaf (GLF) on the refrigeration of fresh-cut apples for preservation. Compared with the CMCS group, apples treated with the CMCS-GLF coating showed better quality (weight loss, browning index, firmness), nutritional value (ascorbic acid and total phenolic content), and microbial safety during storage. The mechanism study indicated that the hydrogen bonding, electrostatic, and hydrophobic interactions between CMCS and GLF (the carboxymethyl moiety of CMCS had the highest response priority and binding strength of the interaction with -C-O of GLF) changed the surface charge distribution and microstructure of CMCS, and increased its molecular weight, particle size, viscosity, and hydrophobicity. Thus, the CMCS-GLF coating exerted better bioactivities (antibacterial and antioxidant activity), and its film showed better mechanical and barrier properties. These results revealed that the noncovalent interaction with GLF could modify the physiochemical properties of CMCS, which was beneficial to improve its bioactivity and application value in fresh fruit preservation.

Recent Advances in the Incorporation of Polysaccharides with Antioxidant and Antibacterial Functions to Preserve the Quality and Shelf Life of Meat Products

Meat and meat products are susceptible to various types of natural processes such as oxidative degradation due to their high content of protein and essential amino acids. However, finding solutions to maintain the nutritional and sensory quality of meat and meat products is unavoidable. Hence, there is a pressing need to investigate alternatives to synthetic preservatives, focusing on active biomolecules of natural provenance. Polysaccharides are natural polymers of various sources that exhibit antibacterial and antioxidant properties via a variety of mechanisms, owing to their diversity and structural variation. For this reason, these biomolecules are widely studied in order to improve texture, inhibit the growth of pathogens, and improve the oxidative stability and sensory characteristics of meat products. However, the literature has not addressed their biological activity in meat and meat products. This review summarizes the various sources of polysaccharides, their antioxidant and antibacterial activities (mainly against pathogenic food strains), and their use as natural preservatives to replace synthetic additives in meat and meat products. Special attention is given to the use of polysaccharides to improve the nutritional value of meat, resulting in more nutrient-rich meat products with higher polysaccharide content and less salt, nitrites/nitrates, and cholesterol.

Inhibitory effects of fucoidan from Laminaria japonica against some pathogenic bacteria and SARS-CoV-2 depend on its large molecular weight

Fucoidan is a highly sulfated polysaccharide with a wide range of bioactivities, including anti-pathogenic activity. However, the relationship between structure and activity of fucoidan in inhibiting pathogen infections remains unclear. Here, different-molecular-weight fucoidans were prepared by photocatalytic degradation followed by membrane ultrafiltration, and their chemical structures and anti-pathogenic microbiota activity were compared. Results showed that photocatalytic degradation could effectively degrade fucoidan while its structure block and sulfate groups were not destroyed obviously. Fucoidan (90.8 kDa) of 5 mg/mL could inhibit the growth of S. aureus, S. typhimurium and E. coli, but its degradation products, Dfuc1 (19.2 kDa) and Dfuc2 (5.5 kDa), demonstrated lower inhibitory effect. In addition, compared to Dfuc1 and Dfuc2, fucoidan showed stronger capability to prevent the adhesion of S. aureus, L. monocytogenes, V. parahaemolyticus and S. typhimurium to HT-29 cells. Moreover, the inhibitory effect against SARS-CoV-2 and the binding activity to S protein were also positively correlated to molecular weight. These results indicate that natural fucoidan with higher molecular weight are more effective to inhibit these pathogenic bacteria and SARS-CoV-2, providing a better understanding of the relationship between structure and activity of fucoidan against pathogenic microbiota.

Thymol Edible Coating Controls Postharvest Anthracnose by Regulating the Synthesis Pathway of Okra Lignin

Okra has received extensive attention due to its high nutritional value and remarkable functional characteristics, but postharvest diseases have severely limited its application. It is important to further explore the methods and potential methods to control the postharvest diseases of okra. In this study, Colletotrichum fioriniae is the major pathogen that causes okra anthracnose, which can be isolated from naturally decaying okra. The pathogenicity of C. fioriniae against okra was preliminarily verified, and the related biological characteristics were explored. At the same time, an observational study was conducted to investigate the in vitro antifungal effect of thymol edible coating (TKL) on C. fioriniae. After culturing at 28 °C for 5 days, it was found that TKL showed an obvious growth inhibition effect on C. fioriniae. The concentration for 50% of the maximal effect was 95.10 mg/L, and the minimum inhibitory concentration was 1000 mg/L. In addition, it was found that thymol edible coating with a thymol concentration of 100 mg/L (TKL100) may cause different degrees of damage to the cell membrane, cell wall, and metabolism of C. fioriniae, thereby inhibiting the growth of hyphae and causing hyphal rupture. Refer to the results of the in vitro bacteriostatic experiment. Furthermore, the okra was sprayed with TKL100. It was found that the TKL100 coating could significantly inhibit the infection of C. fioriniae to okra, reduce the rate of brown spots and fold on the okra surface, and inhibit mycelium growth. In addition, the contents of total phenols and flavonoids of okra treated with TKL100 were higher than those of the control group. Meanwhile, the activities of phenylalaninammo-nialyase, cinnamic acid-4-hydroxylase, and 4-coumarate-CoA ligase in the lignin synthesis pathway were generally increased, especially after 6 days in a 28 °C incubator. The lignin content of TKL-W was the highest, reaching 65.62 ± 0.68 mg/g, which was 2.24 times of that of CK-W. Therefore, TKL may promote the synthesis of total phenols and flavonoids in okra, then stimulate the activity of key enzymes in the lignin synthesis pathway, and finally regulate the synthesis of lignin in okra. Thus, TKL could have a certain controlling effect on okra anthracnose.