An overview on natural polysaccharides with antioxidant properties

Anticancer Mechanism of Astragalus Polysaccharide and Its Application in Cancer Immunotherapy

Astragalus polysaccharide (APS) derived from A. membranaceus plays a crucial role in traditional Chinese medicine. These polysaccharides have shown antitumor effects and are considered safe. Thus, they have become increasingly important in cancer immunotherapy. APS can limit the spread of cancer by influencing immune cells, promoting cell death, triggering cancer cell autophagy, and impacting the tumor microenvironment. When used in combination with other therapies, APS can enhance treatment outcomes and reduce toxicity and side effects. APS combined with immune checkpoint inhibitors, relay cellular immunotherapy, and cancer vaccines have broadened the application of cancer immunotherapy and enhanced treatment effectiveness. By summarizing the research on APS in cancer immunotherapy over the past two decades, this review elaborates on the anticancer mechanism of APS and its use in cancer immunotherapy and clinical trials. Considering the multiple roles of APS, this review emphasizes the importance of using APS as an adjunct to cancer immunotherapy and compares other polysaccharides with APS. This discussion provides insights into the specific mechanism of action of APS, reveals the molecular targets of APS for developing effective clinical strategies, and highlights the wide application of APS in clinical cancer therapy in the future.

Ganoderma lucidum: Multifaceted mechanisms to combat diabetes through polysaccharides and triterpenoids: A comprehensive review

Diabetes is a chronic metabolic disorder. Diabetes complications can affect many organs and systems in the body. Ganoderma lucidum (G. lucidum) contains various compounds that have been studied for their potential antidiabetic effects, including polysaccharides, triterpenoids (ganoderic acids, ganoderol B), proteoglycans, and G. lucidum extracts. G. lucidum polysaccharides (GLPs) and triterpenoids have been shown to act through distinct mechanisms, such as improving glucose metabolism, modulating the mitogen-activated protein kinase (MAPK) system, inhibiting the nuclear factor-kappa B (NF-κB) pathway, and protecting the pancreatic beta cells. While GLPs exhibit a significant role in controlling diabetic nephropathy and other associated complications. This review states the G. lucidum antidiabetic mechanisms of action and potential biologically active compounds that contribute to diabetes management and associated complications. To make G. lucidum an appropriate replacement for the treatment of diabetes with fewer side effects, more study is required to completely comprehend the number of physiologically active compounds present in it as well as the underlying cellular mechanisms that influence their effects on diabetes.

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.

Semisynthesis and characterization of versatile azide intermediates using sodium alginate and its homopolymeric derivatives as starting material

Alginate, a polyuronic biopolymer composed of mannuronic and guluronic acid units, contain hydroxyl and carboxyl groups as targeting modification sites to obtain structures with new and/or improved biological properties. The copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a versatile click reaction for polymer functionalization, but it typically requires a "pre-click" modification to introduce azide or alkyne groups. Here, we described a straightforward chemical path to selectively modify alginate carboxyl groups producing versatile azido derivatives through N-acylation using 3-azydopropylamine. The resulting azide-functionalized polysaccharides underwent click chemistry to yield amino derivatives, confirmed by NMR and FTIR analyses. The 1H NMR spectrum reveals a characteristic triazole group signal at 8.15 ppm. The absence of the azide FTIR band for all amino derivatives, previously observed for the N-acylation products, indicated reaction success. Antibacterial and antioxidant assessments revealed that the initial polysaccharide lacks E. coli inhibition, while the click chemistry-derived amine products exhibit growth inhibition at 5.0 mg/mL. Lower molecular weight derivatives demonstrate superior DPPH scavenging ability, particularly amino-derivatives (24-33 % at 1.2 mg/mL). This innovative chemical pathway offers a promising strategy for developing polysaccharide structures with enhanced properties, demonstrating potential applications in various fields.

Extraction, structure and antioxidant activity of the polysaccharides from morels (Morchella spp.): A review

Morels (Morchella spp.), which are cultivated only in a few regions of the world, are edible mushrooms known for their various properties including antioxidation, immune regulation, antiinflammation, and antitumor effects. Polysaccharides from Morchella are principally responsible for its antioxidant activity. This paper reviews the extraction, purification, structural analysis and antioxidant activity of Morchella polysaccharides (MPs), providing updated research progress. Meanwhile, the structural-property relationships of MPs were further discussed. In addition, based on in vitro and in vivo studies, the major factors responsible for the antioxidant activity of MPs were summarized including scavenging free radicals, reduction capacity, inhibitory lipid peroxidation activity, regulating the signal transduction pathway, reducing the production of ROS and NO, etc. Finally, we hope that our research can provide a reference for further research and development of MPs.

Advancements in Regenerative Hydrogels in Skin Wound Treatment: A Comprehensive Review

This state-of-the-art review explores the emerging field of regenerative hydrogels and their profound impact on the treatment of skin wounds. Regenerative hydrogels, composed mainly of water-absorbing polymers, have garnered attention in wound healing, particularly for skin wounds. Their unique properties make them well suited for tissue regeneration. Notable benefits include excellent water retention, creating a crucially moist wound environment for optimal healing, and facilitating cell migration, and proliferation. Biocompatibility is a key feature, minimizing adverse reactions and promoting the natural healing process. Acting as a supportive scaffold for cell growth, hydrogels mimic the extracellular matrix, aiding the attachment and proliferation of cells like fibroblasts and keratinocytes. Engineered for controlled drug release, hydrogels enhance wound healing by promoting angiogenesis, reducing inflammation, and preventing infection. The demonstrated acceleration of the wound healing process, particularly beneficial for chronic or impaired healing wounds, adds to their appeal. Easy application and conformity to various wound shapes make hydrogels practical, including in irregular or challenging areas. Scar minimization through tissue regeneration is crucial, especially in cosmetic and functional regions. Hydrogels contribute to pain management by creating a protective barrier, reducing friction, and fostering a soothing environment. Some hydrogels, with inherent antimicrobial properties, aid in infection prevention, which is a crucial aspect of successful wound healing. Their flexibility and ability to conform to wound contours ensure optimal tissue contact, enhancing overall treatment effectiveness. In summary, regenerative hydrogels present a promising approach for improving skin wound healing outcomes across diverse clinical scenarios. This review provides a comprehensive analysis of the benefits, mechanisms, and challenges associated with the use of regenerative hydrogels in the treatment of skin wounds. In this review, the authors likely delve into the application of rational design principles to enhance the efficacy and performance of hydrogels in promoting wound healing. Through an exploration of various methodologies and approaches, this paper is poised to highlight how these principles have been instrumental in refining the design of hydrogels, potentially revolutionizing their therapeutic potential in addressing skin wounds. By synthesizing current knowledge and highlighting potential avenues for future research, this review aims to contribute to the advancement of regenerative medicine and ultimately improve clinical outcomes for patients with skin wounds.

Toward Enhanced Antioxidant and Protective Potential: Conjugation of Corn Cob Xylan with Gallic Acid as a Novel Approach

Maize ranks as the second most widely produced crop globally, yielding approximately 1.2 billion tons, with corn cob being its primary byproduct, constituting 18 kg per 100 kg of corn. Agricultural corn production generates bioactive polysaccharide-rich byproducts, including xylan (Xyl). In this study, we used the redox method to modify corn cob xylan with gallic acid, aiming to enhance its antioxidant and protective capacity against oxidative stress. The conjugation process resulted in a new molecule termed conjugated xylan-gallic acid (Xyl-GA), exhibiting notable improvements in various antioxidant parameters, including total antioxidant capacity (1.4-fold increase), reducing power (1.2-fold increase), hydroxyl radical scavenging (1.6-fold increase), and cupric chelation (27.5-fold increase) when compared with unmodified Xyl. At a concentration of 1 mg/mL, Xyl-GA demonstrated no cytotoxicity, significantly increased fibroblast cell viability (approximately 80%), and effectively mitigated intracellular ROS levels (reduced by 100%) following oxidative damage induced by H2O2. Furthermore, Xyl-GA exhibited non-toxicity toward zebrafish embryos, offered protection against H2O2-induced stress, and reduced the rate of cells undergoing apoptosis resulting from H2O2 exposure. In conclusion, our findings suggest that Xyl-GA possesses potential therapeutic value in addressing oxidative stress-related disturbances. Further investigations are warranted to elucidate the molecular structure of this novel compound and establish correlations with its pharmacological activities.

Antiproliferative activity and apoptosis‑inducing effects of Trametes polyzona polysaccharides against human breast cancer cells

Fungal polysaccharides have garnered interest due to their biological activities in terms of anticancer properties and antioxidant activity. The present study aimed to evaluate the anticancer properties and antioxidant activity of a newly isolated white-rot fungus, Trametes polyzona CU07 from Thailand. Crude T. polyzona polysaccharides (CTPPs) were extracted from mycelia using hot water. The chemical properties, including total carbohydrates, molecular weight and protein content, and Fourier-transform infrared spectroscopy analysis, were then investigated. The antioxidant activity was determined against the radicals 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The anticancer properties were evaluated in MCF-7 breast cancer (BC) cells, whereas the 293 cell line was used as a control. The inhibitory effects of CTPPs on viability were determined by MTT assay, followed by BrdU incorporation assay to assess cell proliferation. The induction of apoptosis was determined by flow cytometry. CTPPs were considered polysaccharide-protein conjugates, which had molecular weights in the range of 0.3-22,528 kDa. They contained ~50 and 37% carbohydrate and protein, respectively, with glucose as the main monosaccharide component. Notably, CTPPs had high antioxidant activity against ABTS, and had a significant inhibitory effect on the MCF-7 cell line with a half-maximal inhibitory concentration value of 0.58 mg/ml. However, they exhibited little effect on the 293 cell line. The BrdU incorporation assay demonstrated that CTPPs inhibited proliferation by ~20% compared with that in untreated cells. CTPPs also induced early- and late-stage apoptosis of MCF-7 cells. These results indicated that the CTPPs may exhibit potential antiproliferative and antioxidant activity, and apoptosis-inducing effects against human BC cells.

The Antioxidant and Anti-Complementary Activities of Crude Polysaccharides from Trifoliate Orange (Poncirus trifoliate) Seeds

In this study, I extracted the crude polysaccharides from trifoliate orange (Poncirus trifoliate) seeds, known as TSCP, using water extraction and ethanol precipitation. The monosaccharide composition of TSCP was in the following order: arabinose (28.28 mol%)> galactose (16.76 mol%)> galacturonic acid+glucuronic acid (13.6 mol%)> glucose (12.45 mol%)> rhamnose (4.18 mol%)> mannose (0.57 mol%)> fucose (0.32 mol%). Its total polyphenol contents were 28.66 and 70.96 μg/mL at 1 and 10 mg/mL, respectively (P<0.01). Further, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity of 10 mg/mL TSCP (31.67%) was higher than that of 1 mg/mL TSCP (8.07%; P<0.01) and also higher than its 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (11.97%) at the same concentration (10 mg/mL; P<0.01). The anti-complementary property of TSCP increased in a concentration-dependent manner (P<0.001), and at 1,000 μg/mL, it was comparable (61.36%) to the positive control (60%) consisting of polysaccharide-K. In conclusion, TSCP might be a potential immune modulator.

Optimum Reaction Conditions for the Synthesis of Selenized Ornithogalum caudatum Ait. (Liliaceae) Polysaccharides and Measurement of Their Antioxidant Activity In Vivo

This study determined the optimum reaction conditions for synthesizing selenium-containing polysaccharides. Polysaccharide IIA (with the highest yield) from Ornithogalum caudatum Ait. (Liliaceae) (OCAPIIA) was extracted and purified. Then, three parameters were selected to optimize the synthesis of selenized OCAPIIA (Se-OCAPIIA) using the Box-Behnken design (BBD) and response surface methodology (RSM). The morphology of Se-OCAPIIA was analyzed by scanning electron microscopy (SEM). The characteristic peaks and the monosaccharide composition of Se-OCAPIIA were evaluated by Fourier-transform infrared spectroscopy and gas chromatography. A D-galactose-induced aging mouse model was established, and the in vivo antioxidant activity of Se-OCAPIIA was measured. The optimal conditions for the synthesis of Se-OCAPIIA were as follows: reaction temperature, 72.38 °C; Na2SeO3 to OCAPIIA mass ratio, 0.93 g/g; and reaction time, 8.05 h. The selenium content of Se-OCAPIIA obtained using the optimized process was 3.131 ± 0.090 mg/g, close to the maximum predicted value (3.152 mg/g). Se-OCAPIIA contained D-mannose, D-glucose, and D-galactose at a molar ratio of 1.00:0.34:0.88. SEM showed that Se-OCAPIIA was spherical and flocculated. Compared with OCAPIIA, Se-OCAPIIA exhibited two characteristic peaks at 833 and 610 cm-1 in the infrared spectrum. Se-OCAPIIA increased catalase, glutathione peroxidase, and superoxide dismutase activities and decreased MDA concentrations in the mouse liver. Moreover, Se-OCAPIIA treatment improved liver morphology, decreased the levels of IL-1β and IL-6, and increased IL-10 concentration. In conclusion, the synthesis of Se-OCAPIIA is effective, simple, and feasible. Se-OCAPIIA demonstrated high antioxidant activity in vivo and is a promising antioxidant and therapeutic agent.

Extraction and Purification, Structural Characterization and Biological Activity of a Polysaccharide, PRP-1, from Plumeria rubra

Polysaccharides derived from the flowers of Plumeria rubra (PRP) have shown a variety of beneficial effects on improving human health. However, the structural features and bioactivities of PRP remain unclear. A novel neutral polysaccharide (named PRP-1) with a molecular weight of 23 kDa was extracted and purified from the flowers of P. rubra. PRP-1 was consisted of arabinose, galactose, glucose, xylose and mannose, with a molar ratio of 1.49: 27.89: 50.24: 13.02: 7.36. The structural characterization based on the methylation and 1D/2D nuclear magnetic resonance analyses indicated that PRP-1 was composed of →4)-Glcp-(1→, →4,6)-Glcp-(1→, →4)-Galp-(1→, →2)-Galp-(1→, t-Gal(p), →4)-Manp-(1→, →4,6)-Manp-(1→, t-Man(p), →2)-Xylp-(1→, and t-Xyl(p). Scanning electron microscopy revealed that PRP-1 possess a compact three-dimensional curling network structure in the terms of morphology. PRP-1 exhibited anti-inflammatory activity, which have moderate inhibitory effects on TNF-α and IL-6 production in lipopolysaccharide (LPS)-induced RAW 264.7 cells. In addition, PRP-1 showed ABTS, OH radicals scavenging and the Fe2+ chelating effects in a concentration dependent manner. In α-glucosidase inhibition assay, PRP-1 did not exhibit inhibitory activity. Overall, these results provide a scientific basis for the utilization of the flowers of P. rubra as a potential functional food ingredient.

Flammulina velutipes polysaccharide counteracts cadmium-induced gut injury in mice via modulating gut inflammation, gut microbiota and intestinal barrier

Cadmium (Cd), as Group I carcinogen, can induce damage to various organs including the gut. It is of great importance to meet the rising demand for effective therapies against Cd-induced damage and investigate the mechanism. Flammulina velutipes is a popular edible mushroom, despite the well-known health benefits of Flammulina velutipes, little is known about the effect of its polysaccharide (FVP) against CdCl₂-intestinal injury. In this study, a FVP (uronic acid, 5.10 %; degree of methylation, 41.24 %) was produced via hot water extraction (85 °C) and ethanol precipitation. The FVP contained eight major monosaccharides and exhibited good thermal stability at temperatures lower than 139.73 °C. FVP (100 mg/kg b. w., gavage for 4 weeks) alleviated CdCl₂ (1.5 mg/kg b. w., gavage for 4 weeks)-induced intestinal inflammation and apoptosis, intestinal permeability alteration and intestinal barrier disruption. FVP increased the abundance of Bacteroides, whilst decreasing the abundance of Desulfovibrionales and Clostridium. FVP also restored the levels of short-chain fatty acids (SCFAs), including acetic, propionic, isobutyric, butyric, isovaleric and valeric acids. Correlation analysis indicated the interplays among the FVP, gut microbes, SCFAs, intestinal barrier/cells and gut inflammation. FVP enhances the metabolic functions of gut microbiota via functional pathways analyzed by KEGG database. Furthermore, gut microbial transplantation of FVP + CdCl₂ group mice partially alleviated CdCl₂ caused-gut damage. Thus, FVP may be an effective therapeutic agent against CdCl₂-induced gut damage via SCFA-mediated regulation of intestinal inflammation and gut microbiota-related energy metabolism. This study may open a new avenue for developing alternative strategies to prevent CdCl₂-caused injury.

How Long Will It Take to Launch an Effective Helicobacter pylori Vaccine for Humans?

Helicobacter pylori infection often occurs in early childhood, and can last a lifetime if not treated with medication. H. pylori infection can also cause a variety of stomach diseases, which can only be treated with a combination of antibiotics. Combinations of antibiotics can cure H. pylori infection, but it is easy to relapse and develop drug resistance. Therefore, a vaccine is a promising strategy for prevention and therapy for the infection of H. pylori. After decades of research and development, there has been no appearance of any H. pylori vaccine reaching the market, unfortunately. This review summarizes the aspects of candidate antigens, immunoadjuvants, and delivery systems in the long journey of H. pylori vaccine research, and also introduces some clinical trials that have displayed encouraging or depressing results. Possible reasons for the inability of an H. pylori vaccine to be available over the counter are cautiously discussed and some propositions for the future of H. pylori vaccines are outlined.

Structural characterization and in vitro hepatoprotective activity of a novel antioxidant polysaccharide from fruiting bodies of the mushroom Pleurotus ferulae

In the present study, three novel antioxidant polysaccharides (G-1, AG-1, and AG-2) were isolated and purified from Pleurotus ferulae using mouse erythrocyte hemolysis inhibitory activity as an indicator. These components showed antioxidant activity at the chemical and cellular levels. Given that G-1 displayed superior performance in protecting the human hepatocyte L02 cells against oxidative damage caused by H₂O₂ compared to AG-1 and AG-2 and had a higher yield and purification rate, the detailed structure of G-1 was further characterized. G-1 mainly contains six kinds of linkage type units as A: →4,6)-α-d-Glcp-(1→, B: →3)-β-d-Glcp-(1→, C: →2,6)-β-d-Glcp-(1→, d: β-d-Manp(1→, E: →6)-β-d-Galp-(1→, F: →4)-β-d-Glcp-(1→. Finally, the potential in vitro hepatoprotective mechanism of G-1 was discussed and elucidated. Results suggested that G-1 can protect L02 cells from H₂O₂-induced damage by reducing the leakage of AST and ALT from the cytoplasm, enhancing the activities of SOD and CAT, and suppressing lipid peroxidation and production of LDH. G-1 could further reduce the production of ROS, stabilize mitochondrial membrane potential and maintain cell morphology. Hence, G-1 could be a valuable functional food with antioxidant and hepatoprotective activities.

Antioxidant, antibacterial, and anti-inflammatory Periplaneta americana remnant chitosan/polysaccharide composite film: In vivo wound healing application evaluation

Periplaneta americana (P. americana), which is widely used for wound healing in China, produces a large amount of solid waste (P. americana remnant) after pharmaceutical production extraction. P. americana remnant chitosan (PAC) has a low molecular weight, low crystallinity, and easily modifiable structural properties. In this study, PAC and P. americana remnant polysaccharide (PAP) were used as raw materials to prepare a composite film (PAPCF). The good biocompatibility of the composite film was verified by cell proliferation assays and protein adsorption assays. The bioactivity of the composite film was assessed by antibacterial and in vivo/vitro antioxidant assays to evaluate its potential as a wound dressing. The wound healing experiment revealed that PAPCF improved wound closure and collagen deposition, decreased reactive oxygen species levels, and attenuated the inflammatory response, enabling rapid wound healing from the inflammatory phase to the proliferative phase in mice. Additionally, PAPCF was administered only once, reducing the chance of infection from multiple deliveries. In summary, this paper presents an easy-to-administer, cost-effective, and effective dressing candidate for wound treatment based on the environmental concept of resource reuse.

Extraction, Characterization, and Antioxidant Activity of Polysaccharides from Ajwa Seed and Flesh

The date palm has been cultivated in dry and hot areas of the planet for much of human history. In the Kingdom of Saudi Arabia, dates are the main crop used as a source of food. Among several species of date fruits, the Ajwa AL-Madinah date is unique, growing only in Al-Madinah geographical region. The Ajwa date is used in traditional medicine due to its abundant active components and therapeutic properties. This study investigates the structural properties and the antioxidant effects of water-soluble polysaccharides extracted from Ajwa flesh and seed. The polysaccharides were isolated by two techniques including hot water and ultrasonic extraction. After isolation and partial purification, the physicochemical properties of four samples of polysaccharides extracted from flesh and seed were studied by several techniques including FTIR, solid-state NMR, elemental analysis, and mass spectrometry. Several radical scavenging experiments were combined to study the antioxidant activity of the polysaccharide compounds. FTIR and NMR results showed a structure typical of heterogeneous polysaccharides. Mass spectrometry revealed that the polysaccharide samples were composed mainly of mannose, glucose, galactose, xylose, arabinose, galacturonic acid, and fucose. In addition, the physicochemical properties and composition of polysaccharides extracted from flesh and seed were compared. The extracted polysaccharides showed antioxidant activity, with 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, Fe chelating ability, hydroxyl free radical scavenging ability, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. These results highlight their potential to be a useful nutritional element or supplemental medication.

Protective effect of Cistanche deserticola on gentamicin-induced nephrotoxicity in rats

Objective

Gentamicin (GM) is a commonly used aminoglycoside antibiotic, however, renal toxicity has limited its usage. The present study was designed to evaluate the ameliorative effect of Cistanche deserticola on GM-induced nephrotoxicity in rats.

Methods

The nephrotoxicity in rats was induced by intraperitoneal administration of GM (100 mg/kg) for 10 consecutive days. Glomerular filtration rate, blood urea nitrogen, creatinine and kidney histopathology were detected to assess the GM-induced nephrotoxicity. The oxidative stress (catalase, superoxide dismutase, glutathione and malondialdehyde) was assessed. The inflammatory response (tumor necrosis factor-α, interleukin-6, myeloperoxidase and nuclear factor-kappa B) and apoptotic marker (Bax and Bcl-2) were also evaluated.

Results

The results showed that water and 75% ethanol extracts of C. deserticola (named CDW and CDE, respectively) (100, 200 and 400 mg/kg) in combination with GM could recover the reduction of glomerular filtration rate and enhance the renal endogenous antioxidant capability induced by GM. The increase in the expression of renal inflammatory cytokines (tumor necrosis factor-α and interleukin-6), nuclear protein of nuclear factor-kappa B (p65) and the activity of myeloperoxidase induced by GM was significantly decreased upon CDW or CDE treatment. In addition, CDW or CDE treatment could decrease the Bax protein expression and increase the Bcl-2 protein expression in GM-induced nephrotoxicity in rats significantly.

Conclusion

The study demonstrated that C. deserticola treatment could attenuate kidney dysfunction and structural damage in rats induced by GM through the reduction of inflammation, oxidative stress and apoptosis.

Evaluation of the antimicrobial effects of Capsicum, Nigella sativa, Musa paradisiaca L., and Citrus limetta: A review

The extensive use of antibiotics and vaccines against microbial infections can result in long-term negative effects on humans and the environment. However, there are a number of plants that have antimicrobial effects against various disease-causing microbes such as bacteria, viruses, and fungi without negative side effects or harm to the environment. In this regard, four particular plants- Capsicum, Nigella sativa, Musa paradisiaca L., and Citrus limetta have been widely considered due to their excellent antimicrobial effect and ample availability. In this review, we discuss their antimicrobial effects due to the presence of thymoquinone, p-cymene, pinene, alkaloids, limonene, camphene, and melanin. These antimicrobial compounds disrupt the cell membrane of microbes, inhibit cellular division, and form biofilm in bacterial species, eventually reducing the number of microbes. Extraction of these compounds from the respective plants is carried out by different methods such as soxhlet, hydro-distillation, liquid-liquid extraction (LLE), pressurized liquid extraction (PLE), solid-phase extraction (SPE), supercritical fluid extraction (SFE), pulsed electric field (PEF), microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), ultrasound-assisted extraction (UAE), and high-voltage electrical discharge. Suitable selection of the extraction technique highly depends upon the associated advantages and disadvantages. In order to aid future study in this field, this review paper summarizes the advantages and disadvantages of each of these approaches. Additionally, the discussion covers how antimicrobial agents destroy harmful bacteria. Thus, this review offers in-depth knowledge to researchers on the antibacterial properties of Capsicum, Nigella sativa, Musa paradisiaca L. peels, and Citrus limetta.

The effects of natural active substances in food on the toxicity of patulin

Patulin (PAT) is a mycotoxin, a secondary metabolite mainly produced by fungi of the genera Aspergillus, Byssochlamys, and Penicillium. Many studies have looked into the potential impacts of this mycotoxin due to its high risk. Researchers are currently doing a more in-depth investigation of and employing physical, chemical, and biological ways to remove PAT. However, existing technology cannot completely remove it, and the residual PAT will continue to pose a threat to human health. As a result, substances capable of reducing PAT toxicity need be discovered. According to previous studies, natural components in food could reduce the toxicity of PAT. This article will review the different types of active compounds and discus the detoxification processes, as well as give recommendations for decreasing the toxicity of PAT and future research directions.

Isolation, characterisation and complement fixation activity of acidic polysaccharides from Argemone mexicana used as antimalarials in Mali

CONTEXT

Global studies on Argemone mexicana L. (Papaveraceae) traditionally used against malaria in Mali are limited to its low-mass compounds activities, and little information on its bioactive polysaccharides is available.

OBJECTIVE

This study determines the structure and the immunomodulatory activity of polysaccharides from aerial parts of A. mexicana.

MATERIALS AND METHODS

Acidic polysaccharides from this plant material named HMAmA1 and HMAmA2 were isolated from water extracts. Their monosaccharide composition was determined by gas chromatography. Glycosidic linkages were determined using GC-MS. NMR was also applied. The polymers were tested for effects on the human complement system in vitro at different doses.

RESULTS

The monosaccharide composition showed that the two polysaccharides contained in different amounts the following monomers: arabinose, rhamnose, galactose, and galacturonic acid. Overall structural analysis showed the presence of a low ratio of 1,2-linked rhamnose compared to 1,4-linked galacturonic acid with arabinogalactans substituted on position 4 of rhamnose. NMR data showed the presence of galacturonans alternated by rhamnogalacturonans bearing arabinose and galactose units. α-Linkages were found for l-arabinose, l-rhamnose and d-galacturonic acid, while β-linkages were found for d-galactose. The two polysaccharides exhibited strong complement fixation activities, with HMAmA1 being the highest potent fraction. ICH₅₀ value of HMAmA1 was 5 µg/mL, compared to the control BPII being 15.9 µg/mL.

DISCUSSION AND CONCLUSIONS

Polysaccharides form A. mexicana presented a complement fixation effect. The complement system is an important part of the immune defense, and compounds acting on the cascade are of interest. Therefore, these polymers may be useful as immunodulatory agents.

Anti-inflammatory hydrogel dressings and skin wound healing

Hydrogels are promising and widely utilized in the biomedical field. In recent years, the anti-inflammatory function of hydrogel dressings has been significantly improved, addressing many clinical challenges presented in ongoing endeavours to promote wound healing. Wound healing is a cascaded and highly complex process, especially in chronic wounds, such as diabetic and severe burn wounds, in which adverse endogenous or exogenous factors can interfere with inflammatory regulation, leading to the disruption of the healing process. Although insufficient wound inflammation is uncommon, excessive inflammatory infiltration is an almost universal feature of chronic wounds, which impedes a histological repair of the wound in a predictable biological step and chronological order. Therefore, resolving excessive inflammation in wound healing is essential. In the past 5 years, extensive research has been conducted on hydrogel dressings to address excessive inflammation in wound healing, specifically by efficiently scavenging excessive free radicals, sequestering chemokines and promoting M₁ -to-M₂ polarization of macrophages, thereby regulating inflammation and promoting wound healing. In this study, we introduced novel anti-inflammatory hydrogel dressings and demonstrated innovative methods for their preparation and application to achieve enhanced healing. In addition, we summarize the most important properties required for wound healing and discuss our analysis of potential challenges yet to be addressed.

Two strategies of stubborn biofouling strains surviving from NaClO membrane cleaning: EPS shielding and/or quorum sensing

The declined performance of repeated chemically-enhanced-backwashing (CEB) seriously hampered the sustainable operation of membrane bioreactor (MBR) in long-term, and could be partially attributed to the strengthened anti-cleaning properties of residual stubborn microbes. Although plenty of research has been done towards either the model strains or the whole post-CEB microbial community, little was known about the resisting behavior of practical stubborn strains when confronting oxidative stresses induced by NaClO. Hence, this study isolated 21 strains from samples in a large-scale MBR plant with routine CEB treatment. To unravel how they survive and affect membrane fouling, their anti-oxidation ability, fouling potential and quorum sensing (QS) effect before and after NaClO stimuli were evaluated. The composition and molecular weight distribution of extracellular polymeric substance (EPS) were also investigated to understand their roles during the anti-CEB process. It was found that typical stubborn strains tended to secrete more EPS as protective shields, where polysaccharides (especially the ones >1 kDa) made major contribution. However, sometimes EPS could not well resist the stimuli, with consequent low survival rate and high intracellular ROS level. Under such circumstances, stubborn strains would rather choose to be sensitive with surged QS level and quick population regrowth to maintain vitality under the oxidative stresses. Both strategies aggravated biofouling and eventually enhanced the anti-cleaning properties of biofilm.

Current advances and potential trends of the polysaccharides derived from medicinal mushrooms sanghuang

For thousands of years, sanghuang is distinctive as a general designation for a group of precious and rare Chinese medicinal mushrooms. Numerous investigations have revealed that polysaccharide is one of the important biological active ingredients of sanghuang with various excellent biological activities, including antioxidant, anti-aging, anti-tumor, immunomodulatory, anti-inflammatory, anti-diabetic, hepatoprotective, and anti-microbial functionalities. For the past two decades, preparation, structural characterization, and reliable bioactivities of the polysaccharides from fruiting bodies, cultured mycelia, and fermentation broth of sanghuang have been arousing extensive interest, and particularly, different strains, sources, and isolation protocols might result in obvious discrepancies in structural features and bioactivities. Therefore, this review summarizes the recent reports on preparation strategies, structural features, bioactivities, and structure-activity relationships of sanghuang polysaccharides, which will enrich the knowledge on the values of natural sanghuang polysaccharides and support their further development and utilization as therapeutic agents, vaccines, and functional foods in tonic and clinical treatment.

Structural Characterization and In-Vitro Antioxidant and Immunomodulatory Activities of Polysaccharide Fractions Isolated from Artemisia annua L

Arimisia annua L. is an important anticancer herb used in traditional Chinese medicine. The molecular basis underpinning the anticancer activity is complex and not fully understood, but the herbal polysaccharides, broadly recognised as having immunomodulatory, antioxidant and anticancer activities, are potential key active agents. To examine the functions of polysaccharides from A. annua, their immunomodulatory and antioxidant potentials were evaluated, as well as their structural characterization. The water-soluble polysaccharides (AAPs) were fractionated using size-exclusion chromatography to obtain three dominant fractions, AAP-1, AAP-2 and AAP-3, having molecular masses centered around 1684, 455 and 5.8kDa, respectively. The antioxidant potentials of the isolated polysaccharides were evaluated by measuring radical scavenging activities against DPPH● (2,2-diphenyl-1-picrylhydrazyl radical), ABTS●+ (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical ion), and the OH● (hydroxyl radical). AAP-1 displayed high antioxidant activities against these radicals, which were 68%, 73% and 78%, respectively. AAP-2 displayed lower scavenging activities than the other two fractions. Immunostimulatory activities of AAPs were measured using mouse macrophages. The three polysaccharide fractions displayed significant antioxidant activities and stimulated the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). AAP-1 showed significant immunostimulatory activity (16-fold increase in the production of IL-6 compared to the control and 13-fold increase in the production of TNF-α) with low toxicity (>60% cell viability at 125 μg/mL concentration). Preliminary structural characterization of the AAPs was carried out using gas chromatography (GC) and FTIR techniques. The results indicate that AAP-1 and AAP-2 are pyranose-containing polysaccharides with β-linkages, and AAP-3 is a β-fructofuranoside. The results suggest that these polysaccharides are potential candidates for immunotherapy and cancer treatment.

In situ exopolysaccharides produced by Lactobacillus helveticus MB2-1 and its effect on gel properties of Sayram ketteki yoghurt

In order to study the mechanism of high viscosity of Sayram ketteki yoghurt, the growth, acidification properties, in situ exopolysaccharides (EPS) production of Lactobacillus helveticus MB2-1 in milk medium were investigated. The microstructure of the yoghurt was analyzed. The characteristics of in situ EPS produced by this strain in yoghurt were studied by high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) analysis. The amount of in situ EPS produced could be up to 689.47 mg/L. The micrographs of Sayram ketteki yoghurt demonstrated that the in situ EPS secreted by ropy L. helveticus MB2-1 were closely connected with proteins, effectively filling the three-dimensional network structure of casein clusters, thereby resulting in high viscosity of yoghurt. Besides, the molecular weight of in situ EPS was 9.34 × 10⁴ Da, and the in situ EPS was determined to be a new heteropolysaccharide, containing fucose, which made it unique. Moreover, the set yoghurts added with in situ EPS were demonstrated fine effects on the texture improvement. These results illustrated that L. helveticus MB2-1 could be set as a good starter and the in situ EPS could be considered as a probiotic stabilizer substitute for fermented dairy products.

Antioxidant, anti-inflammatory and beneficial metabolic effects of botryosphaeran [(1→3)(1→6)-β-d-glucan] are responsible for its anti-tumour activity in experimental non-obese and obese rats bearing Walker-256 tumours

Botryosphaeran, a (1→3)(1→6)-β-d-glucan, presents several beneficial activities, such as antiproliferative, hypoglycemic and antitumoural activities. This study evaluated the effects of botryosphaeran on oxidative stress, inflammation and metabolic activities in Walker-256 tumour-bearing non-obese and obese rats. Wistars rats were divided into four groups: control tumour (CT); control tumour + botryosphaeran (CTB); obese tumour (OT), and obese tumour + botryosphaeran (OTB). In ninth week, obese and non-obese rats were inoculated with 1 × 107 Walker-256 tumour cells and treated with botryosphaeran (30 mg/kg/d for 15 days). In 11th week, the following parameters were evaluated glycogen, glucose and lactate levels, pro-oxidant (TBARS) and antioxidant markers (superoxide dismutase [SOD]; catalase [CAT]; glutathione-S-transferase [GST]; reduced glutathione [GSH]; vitamin C) and cytokines. Obesity presented oxidative stress and inflammation, as demonstrated by high levels of TBARS, SOD and TNF-α, and lower levels of CAT, GSH and interleukin-10 (IL-10). Botryosphaeran significantly decreased TBARS and TNF-α and increased GST, GSH, vitamin C and IL-10 in the liver; increased SOD and vitamin C in tumour tissue; decreased TBARS in adipose tissue, and notably decreased the levels of glycogen and lactate in the tumour of CTB rats. Botryosphaeran promoted significant antioxidant, anti-inflammatory, and beneficial metabolic effects in Walker-256 tumour-bearing non-obese and obese rats, which contributed to its antitumour activity.

Steam explosion pretreatment of Achyranthis bidentatae radix: Modified polysaccharide and its antioxidant activities

Steam explosion technology was employed for the pretreatment of Achyranthis bidentatae radix (ABR) under mild conditions, followed by the polysaccharide extraction. An increase in the extraction yield and uronic acid content of crude polysaccharide were detected, along with a decrease in the protein content induced by the steam explosion. The monosaccharide analysis showed the main compositional modification of polysaccharide is the increase in the proportion of galacturonic acid, galactose, and arabinose. It is consistent with the discriminant analysis of the FT-IR and UV-vis spectra. These structural modifications of crude polysaccharide caused by the steam explosion pretreatment (SEP) resulted in the significant increases in their antioxidant activities in vitro and in vivo. Strong correlations were observed between the pretreatment conditions and the changes in the structural characteristics and antioxidant activities of Achyranthis bidentatae radix polysaccharides (ABPS).

Free Radical Scavenging Capacities and Alleviating Actions of Polysaccharides Extract of Termitomyces le-testui on Methylprednisolone-Induced Immunodepression in Rats

Background

Natural products have been said to show immunomodulatory and antioxidant activities. The research study was aimed to assess the immunomodulatory and free radical scavenging activities of crude polysaccharide from dry mushroom fruiting bodies of Termitomyces le-testui.

Materials and Methods

Hot water extract of polysaccharide extract of T. le-testui was prepared and tested in white albino Wister rats for its immunomodulatory activities effect on methylprednisolone-immunosuppressed animals. In addition, the radical scavenging activity of the polysaccharide was evaluated using nitrite and hydrogen peroxide.

Results

The result of the study showed that the polysaccharide T. le-testui increases the phagocytic index, energy metabolism of macrophages, spleen index, and nitric oxide in a concentration-dependent manner in immunosuppressed animals. Also, it was observed that the extract increased dose-dependent total oxidative stress and thymus index. Finally, the crude polysaccharide-rich extract showed nitrite and hydrogen peroxide scavenging activity in a concentration-dependent manner.

Conclusion

Polysaccharide-rich extract possesses immunomodulatory and antioxidant properties.

Beneficial Effects of Polysaccharides on the Epithelial Barrier Function in Intestinal Mucositis

Intestinal mucositis is a clinically relevant side effect of anticancer therapies. It is experienced by 60–100% of patients undergoing treatment with high doses of chemotherapy, radiation therapy, and bone marrow transplantation. Intestinal mucositis can manifest as pain, weight loss, inflammation, diarrhea, rectal bleeding, and infection; affecting normal nutritional intake and intestinal function. It often impacts adherence to anticancer therapy as it frequently limits patient’s ability to tolerate treatment, causing schedule delays, interruptions, or premature discontinuation. In some cases, local and systemic secondary infections are observed, increasing the costs toward medical care and hospitalization. Several strategies for managing mucositis are available which do not always halt this condition. In this context, new therapeutic strategies are under investigation to prevent or treat intestinal mucositis. Polysaccharides from natural resources have recently become promising molecules against intestinal damage due to their ability to promote mucosal healing and their anti-inflammatory actions. These effects are associated with the protection of intestinal mucosa and regulation of microbiota and immune system. This review aims to discuss the recent advances of polysaccharides from natural resources as potential therapies for intestinal mucositis. The source, species, doses, treatment schedules, and mechanisms of action of polysaccharides will be discussed in detail.

Development and Characterization of Novel Biopolymer Derived from Abelmoschus esculentus L. Extract and Its Antidiabetic Potential

Abelmoschus esculentus (Okra) is an important vegetable crop, widely cultivated around the world due to its high nutritional significance along with several health benefits. Different parts of okra including its mucilage have been currently studied for its role in various therapeutic applications. Therefore, we aimed to develop and characterize the okra mucilage biopolymer (OMB) for its physicochemical properties as well as to evaluate its in vitro antidiabetic activity. The characterization of OMB using Fourier-transform infrared spectroscopy (FT-IR) revealed that okra mucilage containing polysaccharides lies in the bandwidth of 3279 and 1030 cm^-1, which constitutes the fingerprint region of the spectrum. In addition, physicochemical parameters such as percentage yield, percentage solubility, and swelling index were found to be 2.66%, 96.9%, and 5, respectively. A mineral analysis of newly developed biopolymers showed a substantial amount of calcium (412 mg/100 g), potassium (418 mg/100 g), phosphorus (60 mg/100 g), iron (47 mg/100 g), zinc (16 mg/100 g), and sodium (9 mg/100 g). The significant antidiabetic potential of OMB was demonstrated using α-amylase and α-glucosidase enzyme inhibitory assay. Further investigations are required to explore the newly developed biopolymer for its toxicity, efficacy, and its possible utilization in food, nutraceutical, as well as pharmaceutical industries.

Reviews on mechanisms of in vitro antioxidant, antibacterial and anticancer activities of water-soluble plant polysaccharides

Degenerative diseases such as cancer and cardiovascular diseases, and antimicrobial resistance are becoming prominent health problems needing utmost public health attention. Curative interventions such as the use of pharmaceutical drugs and alternative plant medicines are increasingly being explored. Plant polysaccharides have gained attention for their promising bioactivities such as antioxidant, antimicrobial and anticancer activities. Bioactive plant polysaccharides are also being preferred for their relatively few side effects compared to conventional pharmaceuticals. The elucidation of the bioactive potential of plant polysaccharides in disease treatment entails an understanding of the factors that determine their biofunctional properties using functional and mechanistic assays. This review summarizes the literature on the composition, structural, functional, and mechanistic determinations of the antioxidant, anticancer and antimicrobial activities of plant polysaccharides. The outcome of this review highlights the leading trends in the elucidation of the antioxidant, anticancer and antimicrobial activities of plant polysaccharides and underscores the promising health benefits of plant polysaccharides.

Natural biopolymers as proton conductors in bioelectronics

Bioelectronic devices sense or deliver information at the interface between living systems and electronics by converting biological signals into electronic signals and vice-versa. Biological signals are typically carried by ions and small molecules. As such, ion conducting materials are ideal candidates in bioelectronics for an optimal interface. Among these materials, ion conducting polymers that are able to uptake water are particularly interesting because, in addition to ionic conductivity, their mechanical properties can closely match the ones of living tissue. In this review, we focus on a specific subset of ion-conducting polymers: proton (H⁺ ) conductors that are naturally derived. We first provide a brief introduction of the proton conduction mechanism, and then outline the chemical structure and properties of representative proton-conducting natural biopolymers: polysaccharides (chitosan and glycosaminoglycans), peptides and proteins, and melanin. We then highlight examples of using these biopolymers in bioelectronic devices. We conclude with current challenges and future prospects for broader use of natural biopolymers as proton conductors in bioelectronics and potential translational applications.

Biological activities of Pleurotus spp. polysaccharides: A review

Mushrooms are consumed for their nutrients and therapeutic bioactive compounds and are used medicinally in Chinese and Japanese medicine traditions since time immemorial. Members of the genus Pleurotus form a heterogeneous group of edible species with outstanding nutritional profiles rich in fiber, vitamins (thiamine, riboflavin, ascorbic acid, ergosterine, and niacin), micro and macro-elements (phosphorus and iron), and carbohydrates. Pleurotus is one of the most diversified medicinal and edible mushrooms related to the composition of chemical structures such as polysaccharides, glycoproteins, and secondary metabolites such as alkaloids and betalains. The cultivation of Pleurotus spp. on lignocellulosic wastes represents one of the most economically and cost-effective organic recycling processes, especially for the utilization of different feasible and cheap recyclable residues. Also, several Pleurotus spp. have the ability to remove phenolic compounds from wastewater with the action of phenoloxidase activity. Here, we have reviewed the chemistry of such polysaccharides and their reported biological activities, namely, anti-inflammatory, immunomodulatory, anti-diabetic, anti-tumor, antioxidant, etc. The mechanism of action and effects of novel polysaccharides extracted from various species of Pleurotus have been studied. The current study will be beneficial for guiding future research projects on the above concept and investigating more deeply the health of human beings. PRACTICAL APPLICATIONS: Mushrooms are one of the most delicious foods around the globe and have many medicinal properties for decades. Various Pleurotus species have been in focus in recent years because of their palatability and medicinal importance too. It contains many bioactive compounds among which polysaccharides are valued to a great extent. Many biological activities are exerted by polysaccharides derived from the Pleurotus spp., namely, anti-tumor, antioxidant, and many more. They are responsible for significant physiological responses in animals, animal-alternative in vitro models, and humans. Their important physicochemical characteristics benefit their use in the food industry as well. So, the biological activities of these Pleurotus spp. polysaccharides will provide an insight to develop Pleurotus spp. as functional foods, because of their nutritional value and presence of bioactive components.

Effects of Traditional Chinese Medication-Based Bioactive Compounds on Cellular and Molecular Mechanisms of Oxidative Stress

The oxidative stress reaction is the imbalance between oxidation and antioxidation in the body, resulting in excessive production of oxygen free radicals in the body that cannot be removed, leading to excessive oxidation of the body, and causing damage to cells and tissues. A large number of studies have shown that oxidative stress is involved in the pathological process of many diseases, so inhibiting oxidative stress, that is, antioxidation, is of great significance for the treatment of diseases. Studies have shown that many traditional Chinese medications contain antioxidant active bioactive compounds, but the mechanisms of those compounds are different and complicated. Therefore, by summarizing the literature on antioxidant activity of traditional Chinese medication-based bioactive compounds in recent years, our review systematically elaborates the main antioxidant bioactive compounds contained in traditional Chinese medication and their mechanisms, so as to provide references for the subsequent research.

Hydrogen Peroxide Effects on Natural-Sourced Polysacchrides: Free Radical Formation/Production, Degradation Process, and Reaction Mechanism-A Critical Synopsis

Numerous reactive oxygen species (ROS) entities exist, and hydrogen peroxide (H2O2) is very key among them as it is well known to possess a stable but poor reactivity capable of generating free radicals. Considered among reactive atoms, molecules, and compounds with electron-rich sites, free radicals emerging from metabolic reactions during cellular respirations can induce oxidative stress and cause cellular structure damage, resulting in diverse life-threatening diseases when produced in excess. Therefore, an antioxidant is needed to curb the overproduction of free radicals especially in biological systems (in vivo and in vitro). Despite the inherent properties limiting its bioactivities, polysaccharides from natural sources increasingly gain research attention given their position as a functional ingredient. Improving the functionality and bioactivity of polysaccharides have been established through degradation of their molecular integrity. In this critical synopsis; we articulate the effects of H2O2 on the degradation of polysaccharides from natural sources. Specifically, the synopsis focused on free radical formation/production, polysaccharide degradation processes with H2O2, the effects of polysaccharide degradation on the structural characteristics; physicochemical properties; and bioactivities; in addition to the antioxidant capability. The degradation mechanisms involving polysaccharide's antioxidative property; with some examples and their respective sources are briefly summarised.

Drosophila as an emerging model organism for studies of food-derived antioxidants

Dietary supplementation with antioxidants provides health benefits by preventing diseases caused by oxidative stress and damage. Consequently, there has been growing interest in the study of antioxidative foods and their active ingredients. Oxidative stress and antioxidative responses are mechanistically conserved from Drosophila to mammals. Therefore, as a well-established model organism with a short life cycle and advantages of genetic manipulation, the fruit fly has been increasingly employed to assess functions of antioxidants in vivo. In this review, the antioxidative defense mechanisms, methods used and assays developed in Drosophila to evaluate antioxidant supplementation, are highlighted. The main manifestations of antioxidation include reduction of reactive species, up-regulation of endogenous antioxidants, inhibition on oxidative damage to biomacromolecules, enhanced resistance against oxidative stress and extension of lifespan, which are related to the activations of nuclear factor erythroid 2-related factor 2-antioxidant response element pathway and other adaptive responses. Moreover, the key considerations and future perspectives for the application of Drosophila models in the studies of food-derived antioxidants are discussed.

β-Glucans as a panacea for a healthy heart? Their roles in preventing and treating cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Factors increasing the risks for CVD development are related to obesity, diabetes, high blood cholesterol, high blood pressure and lifestyle. CVD risk factors may be treated with appropriate drugs, but prolonged can use cause undesirable side-effects. Among the natural products used in complementary and alternative medicines, are the β-ᴅ-glucans; biopolymers found in foods (cereals, mushrooms), and can easily be produced by microbial fermentation. Independent of source, β-glucans of the mixed-linked types [(1 → 3)(1 → 6)-β-ᴅ-glucans - fungal, and (1 → 3)(1 → 4)-β-ᴅ-glucans - cereal] have widely been studied because of their biological activities, and have demonstrated cardiovascular protective effects. In this review, we discuss the roles of β-ᴅ-glucans in various pathophysiological conditions that lead to CVDs including obesity, dyslipidemia, hyperglycemia, oxidative stress, hypertension, atherosclerosis and stroke. The β-glucans from all of the sources cited demonstrated potential hypoglycemic, hypocholesterolemic and anti-obesogenicity activities, reduced hypertension and ameliorated the atherosclerosis condition. More recently, β-glucans are recognized as possessing prebiotic properties that modulate the gut microbiome and impact on the health benefits including cardiovascular. Overall, all the studies investigated unequivocally demonstrated the dietary benefits of consuming β-glucans regardless of source, thus constituting a promising panaceutical approach to reduce CVD risk factors.

Thymoquinone improves behavioral and biochemical deficits in hepatic encephalopathy induced by thioacetamide in rats

Hepatic encephalopathy (HE) is a cerebral function alteration in patients with liver dysfunction. The present study aimed to evaluate the therapeutic effects of thymoquinone (TQ) on behavioral deficits and its possible mechanism(s) in a thioacetamide (TAA)-induced HE model. HE was induced in male Wistar rats by intraperitoneal (i.p.) injection of TAA (200 mg/kg) for once every 48 h for 14 consecutive days. Thymoquinone (5, 10, and 20 mg/kg) was administered for seven consecutive days (i.p.) after HE induction. Anxiety and depression-like behaviors assessed by standard paradigms respectively. Finally, their brain hippocampus sections prepared to evaluate the oxidative stress changes in rats. Data showed treatment HE rats with TQ ameliorated anxiety and depression-like behaviors. TQ administration also reduced oxidative stress due to its potential to enhance the levels of glutathione-peroxidase (GPx), catalase (CAT), and total thiol content in the hippocampus. These findings suggest that TQ has notable effects against acute hepatic failure and HE complications through modulation of oxidative stress.

Isolation, structural characterization, and biological activities of galactomannans from Rhizopogon luteolus and Ganoderma adspersum mushrooms

Polysaccharides are essential compounds that contribute to the biological activities of mushrooms. Two new galactomannans (Galactomannan I and II) were isolated from R. luteolus and G. adspersum. Their structures were characterized using FT-IR, 1D, and 2D-NMR techniques. Both isolated galactomannans I and II mainly include D-mannose and D-galactose in the molar percentages of 0.81:1.0 and 1:1.4, respectively. The GPC calculation demonstrated that the molecular weights are about 5240 and 5090 Da, respectively. Their structures comprise of β-(1,4)-mannose (Man) backbone units with α-(1,6)-galactose (Gal) single unit as a side group. The anticholinesterase activity of galactomannans was tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), spectrophotometrically. Antioxidant activity was also measured by six assays (ABTS^•+, DPPH^•, O₂^•-, β-carotene-linoleic acid, metal chelating, and CUPRAC assays). Galactomannan II indicated close inhibitory activity to galantamine against AChE (61.04 ± 0.45%) and BChE (59.70 ± 1.15%) at 50 μg/mL concentration. Nevertheless, both galactomannans showed low antioxidant activity in all tests. This study reveals that mainly, Galactomannan II could be used as a new natural promising anticholinesterase agent.

Structure and biological properties of exopolysaccharide isolated from Citrobacter freundii

This study aimed to investigate the molecular characterization, antioxidant activity in vitro, cytotoxicity study of an exopolysaccharide isolated from Citrobacter freundii. Firstly, the culture conditions were standardized by the Design of experiments (DoE) based approach, and the final yield of thecrude exopolysaccharide was optimized at 2568 ± 169 mg L^-1. One large fraction of exopolysaccharide was obtained from the culture filtrate by size exclusion chromatography and molecular characteristics were studied. A new mannose rich exopolysaccharide (Fraction-I) with average molecular weight ~ 1.34 × 10⁵ Da was isolated. The sugar analysis showed the presence of mannose and glucose in a molar ratio of nearly 7:2 respectively. The structure of the repeating unit in the exopolysaccharide was determined through chemical and 1D/2D- NMR experiments as: Finally, the antioxidant activity, and the cytotoxicity of the exopolysaccharide were investigated and the relationship with molecular properties was discussed as well.