Structure characterization of Oudemansiella radicata polysaccharide and preparation of selenium nanoparticles to enhance the antioxidant activities

Antibacterial and antioxidant activities of a novel biosynthesized selenium nanoparticles using Rosa roxburghii extract and chitosan: Preparation, characterization, properties, and mechanisms

Developing efficient and safe antibacterial agents to inhibit pathogens including Physalospora piricola and Staphylococcus aureus is of great importance. Herein, a novel compound composed of Rosa roxburghii procyanidin, chitosan and selenium nanoparticle (RC-SeNP) was bio-synthesized, with the average diameter and zeta potential being 84.56 nm and -25.60 mV, respectively. The inhibition diameter of the RC-SeNP against P. piricola and S. aureus reached 18.67 mm and 13.13 mm, and the maximum scavenging activity against DPPH and ABTS reached 96.02% and 98.92%, respectively. Moreover, the RC-SeNP completely inhibited the propagation P. piricola and S. aureus on actual apples, suggesting excellent in vivo antimicrobial capacity. The transcriptome analysis and electron microscope observation indicated that the antibacterial activity would be attributed to adhering to and crack the cell walls as well as damage the cytomembrane and nucleus. Moreover, the RC-SeNP effectively maintained the vitamin C, total acid, and water contents of red bayberry, demonstrating potential application for fruit preservation. At last, the RC-SeNP showed no cell toxicity and trace selenium residual dose (0.03 mg/kg on apple, 0.12 mg/kg on red bayberry). This study would enlighten future development on novel nano-bioantibacterial agents for sustainable agriculture.

Selenium nanoparticles coated bacterial polysaccharide with potent antimicrobial and anti-lung cancer activities

Bacterial exopolysaccharides are homopolymeric or heteropolymeric polysaccharides with large molecular weights (10-1000 kDa). Exopolysaccharides' functional uses and potential have revolutionized the industrial and medicinal industries. Hence, the aim of the present study was to optimize the production of bacterial exopolysaccharide and apply it as a capping agent for selenium nanoparticles synthesis. Exopolysaccharide (EPS) producing Lactic acid bacteria (LAB) were isolated from dairy products then biochemically characterized and assessed for their potential antimicrobial effect. The most potent EPS producer was identified as Lactiplantibacillus plantarum strain A2 with accession number OP218384 using 16S rRNA sequencing. Overall, FTIR data of the extracted EPS revealed similarity with amylopectin spectrum. 1H NMR spectrum revealed an α-anomeric configuration of the glycosidic linkage pattern in the polysaccharides while the 13C NMR spectrum can also be separated into two main portions, the anomeric carbons region (δ 98-102 ppm) and the non-anomeric carbons region (δ 60-81 ppm). Antimicrobial activity of the produced EPS showed maximum activity against Staphylococcus aureus, MRSA, Enterobacter aerogenes, Klebsiella pneumoniae and Candida albicans respectively. The EPS capsule layer surrounding the bacterial cells was detected by TEM study. Optimization of EPS production was evaluated using Taguchi design, trial 23 reported the highest biomass yield and EPS output (6.5 and 27.12 g/L respectively) with 2.4 and 3.3 folds increase (from the basal media) respectively. The optimized exopolysaccharide was used as a capping and stabilizing agent for selenium nanoparticles (EPS-SeNPs) synthesis. Zeta potential, size and PDI of the synthesized nanoparticles were - 19.7 mV, 45-65 nm and 0.446 respectively with strong bactericidal and fungicidal effect against the tested pathogens. Complete microbial growth eradication was recorded after 6, 8 and 10 h against Staphylococcus aureus, Candida albicans and Klebsiella pneumoniae respectively. EPS-SeNPs showed a potent antioxidant effect reached 97.4% and anticancer effect against A549 lung cancer cell line (IC50 reached 5.324 µg/mL). EPS-SeNPs inhibited cancerous cell growth at S phase. Moreover, molecular studies revealed the anti-apoptotic activity of Bcl2's was inhibited and Bax was activated. The present investigation successfully synthesized selenium nanoparticles through bacterial EPS with significantly high antimicrobial and anticancer activity.

Functionalization of selenium nanoparticles with olive polyphenols - impact on toxicity and antioxidative activity

Selenium nanoparticles (SeNPs) represent novel selenium (Se) formulation characterized by improved biocompatibility and a wider therapeutic range in comparison to inorganic Se. The aim of this work was to investigate the possibilities of functionalization of SeNPs with olive pomace extract (OPE), rich in health-promoting polyphenols, and to obtain innovative forms of nutraceuticals. Cytotoxic and antioxidative activities of four types of SeNPs (polyvinylpyrrolidone stabilized (PVP SeNPs), polysorbate stabilized (PS SeNPs), polyvinylpyrrolidone stabilized and functionalized using OPE (f PVP SeNPs) and polysorbate stabilized and functionalized using OPE (f PS SeNPs) were investigated. SeNPs showed lower toxicity on human hepatocellular carcinoma (HepG2) and human colorectal adenocarcinoma (Caco2) cells compared to selenite. Functionalization with polyphenols significantly improved their direct antiradical (f PVP SeNPs: 24.4 ± 1.84 and f PS SeNPs: 30.9 ± 2.47 mg TE/mmol Se) and reducing properties (f PVP SeNPs: 50 ± 3.16 and f PS SeNPs: 53.6 ± 3.22 mg GAE/mmol) compared to non-functionalized SeNPs. The significant impact of tested SeNPs on intracellular antioxidative mechanisms has been observed and it was dependent on both cell type and physico-chemical properties of SeNPs, indicating the complexity of involved mechanisms.

Structure characterization of novel heteropolysaccharides from Pteridium revolutum with antioxidant and antiglycated activities

This study aims to analysis the structures of polysaccharides isolated from Pteridium revolutum and their antioxidant and antiglycated activities. Three novel water-soluble heteropolysaccharides, named PRP0, PRP1, and PRP2, were isolated from P. revolutum. The average molecular weight was determined by high performance gel permeation chromatography analysis as 1.04 × 106, 8.39 × 105, and 7.37 × 105 Da, respectively. Their structures were characterized using physicochemical and spectroscopic methods. The antioxidant and antiglycated activities were assayed in vitro. PRP0, PRP1, and PRP2 consist of l-Ara, l-Rha, d-Man, d-Xyl, d-Fuc, d-Gal, and d-Glc in different proportions. PRP1 mainly has a backbone of (1 → 3,6)-linked d-Man and (1 → 3)-linked d-Gal on main chain. PRP2 is mainly composed of (1 → 2,4)-linked d-Man and (1 → 3)-linked d-Gal on main chain. All polysaccharides have strong scavenging power on 2,2-difenil-1-picril-hidrazil and hydroxyl radicals and significantly antiglycated activity in Bovine serum albumin-Glucose model, which showing that the polysaccharides have potential application value on the functional food.

Selenium Nanoparticles Based on Morinda officinalis Polysaccharides: Characterization, Anti-Cancer Activities, and Immune-Enhancing Activities Evaluation In Vitro

Recently, selenium nanoparticles have been drawing attention worldwide, and it is crucial to increase the stability of nano-Se. Morinda officinalis polysaccharides (MOP) are the main active component in Morinda officinalis radix. However, their low activity has limited their application. A novel selenium nanoparticle (Se-MOP) was prepared to solve these problems using MOP as a dispersant. The zeta potential was measured to evaluate the stability, and UV and ATR-FTIR were used to investigate the binding type of selenium and MOP. The morphology was observed by the TEM method. Furthermore, the inhibitory effect on five selected cancer cells (HepG2, MCF-7, AGS, PC9, and HCT8) was evaluated, showing remarkable inhibition of all five cancer cells. The mechanism of inhibition was also investigated by cell circle assay, and it was found that Se-MOP could induce cell circle G0/G1 phase arrest. Immune-enhancing activities were evaluated by measuring the proliferation and cytokines of mouse spleen lymphocytes in vitro and quantitative RT-PCR. The results indicated that single stimulation of Se-MOP and synergistic stimulation with PHA or LPS increased immune capacity and improved immune by increasing the expression of cytokines.

Structure, stability, antioxidant activity, and controlled-release of selenium nanoparticles decorated with lichenan from Usnea longissima

Selenium nanoparticles (SeNPs) have attracted widespread attention, but the poor water dispersibility restricted their applications seriously. Herein, Usnea longissima lichenan decorated selenium nanoparticles (L-SeNPs) were constructed. The formation, morphology, particle size, stability, physicochemical characteristics, and stabilization mechanism of L-SeNPs were investigated via TEM, SEM, AFM, EDX, DLS, UV-Vis, FT-IR, XPS, and XRD. The results indicated that the L-SeNPs displayed orange-red, amorphous, zero-valent, and uniform spherical nanoparticles with an average diameter of 96 nm. Due to the formation of CO⋯Se bonds or the hydrogen bonding interaction (OH⋯Se) between SeNPs and lichenan, L-SeNPs exhibited better heating and storage stability, which kept stable for more than one month at 25 °C in an aqueous solution. The decoration of the SeNPs surface with lichenan endowed the L-SeNPs with superior antioxidant capability, and their free radicals scavenging ability exhibited in a dose-dependent manner. Furthermore, L-SeNPs showed excellent selenium controlled-release performance. In simulated gastric liquids, selenium release kinetics from L-SeNPs followed the Linear superimposition model, which was governed by the polymeric network retardation of macromolecular, while in simulated intestinal liquids, it was well fitted to the Korsmeyer-Peppas model and followed a Fickian mechanism controlled by diffusion.

Antioxidant Activities of Natural Polysaccharides and Their Derivatives for Biomedical and Medicinal Applications

Many chronic diseases such as Alzheimer's disease, diabetes, and cardiovascular diseases are closely related to in vivo oxidative stress caused by excessive reactive oxygen species (ROS). Natural polysaccharides, as a kind of biomacromolecule with good biocompatibility, have been widely used in biomedical and medicinal applications due to their superior antioxidant properties. In this review, scientometric analysis of the highly cited papers in the Web of Science (WOS) database finds that antioxidant activity is the most widely studied and popular among pharmacological effects of natural polysaccharides. The antioxidant mechanisms of natural polysaccharides mainly contain the regulation of signal transduction pathways, the activation of enzymes, and the scavenging of free radicals. We continuously discuss the antioxidant activities of natural polysaccharides and their derivatives. At the same time, we summarize their applications in the field of pharmaceutics/drug delivery, tissue engineering, and antimicrobial food additives/packaging materials. Overall, this review provides up-to-date information for the further development and application of natural polysaccharides with antioxidant activities.

Synthesis, Characterization of Low Molecular Weight Chitosan Selenium Nanoparticles and Its Effect on DSS-Induced Ulcerative Colitis in Mice

Selenium nanoparticles have attracted extensive attention due to their good bioavailability and activity. In the present study, a new form of selenium nanoparticle (Low molecular weight chitosan selenium nanoparticles (LCS-SeNPs)) were synthesized in a system of sodium selenite and acetic acid. The size, element state, morphology and elementary composition of LCS-SeNPs were characterized by using various spectroscopic and microscopic measurements. The protection of LCS-SeNPs against dextran sulfate sodium (DSS)-induced intestinal barrier dysfunction and the inherent mechanisms of this process were investigated. The results showed that LCS-SeNPs, with an average diameter of 198 nm, zero-valent and orange-red relatively uniform spherical particles were prepared. LCS-SeNPs were mainly composed of C, N, O and Se elements, of which Se accounted for 39.03% of the four elements C, N, O and Se. LCS-SeNPs reduced colon injury and inflammation symptoms and improved intestinal barrier dysfunction. LCS-SeNPs significantly reduced serum and colonic inflammatory cytokines TNF-α and IL-6 levels. Moreover, LCS-SeNPs remarkably increased antioxidant enzyme GSH-Px levels in serum and colonic tissue. Further studies on inflammatory pathways showed that LCS-SeNPs alleviated DSS-induced colitis through the NF-κB signaling pathway, and relieved inflammatory associated oxidative stress through the Nrf2 signaling pathway. Our findings suggested that LCS-SeNPs are a promising selenium species with potential applications in the treatment of oxidative stress related inflammatory intestinal diseases.

Progress in the Surface Functionalization of Selenium Nanoparticles and Their Potential Application in Cancer Therapy

As an essential micronutrient, selenium participates in numerous life processes and plays a key role in human health. In the past decade, selenium nanoparticles (SeNPs) have attracted great attention due to their excellent functionality for potential applications in pharmaceuticals. However, the utilization of SeNPs has been restricted by their instability and low targeting ability. Since the existing reviews mainly focused on the applications of SeNPs, this review highlights the synthesis of SeNPs and the strategies to improve their stability and targeting ability through surface functionalization. In addition, the utilization of functionalized SeNPs for the single and co-delivery of drugs or genes to achieve the combination of therapy are also presented, with the emphasis on the potential mechanism. The current challenges and prospects of functionalized SeNPs are also summarized. This review may provide valuable information for the design of novel functionalized SeNPs and promote their future application in cancer therapy.

Targeted and untargeted metabolomic analyses and biological activity of Tibetan tea

Tibetan tea is not only a national product of geographical identity, but also a traditional beverage inherits Chinese tradition. This study evaluated the metabolic profiles and biological activity in four Tibetan teas. 83 non-volatile metabolites were identified as differentially expressed metabolites, including amino acids and their derivatives, phenolic acids, flavonoids, nucleotides and their derivatives, terpenes, alkaloids, organic acids, lipids and others. CC and 131 were rich in terpenoids and lipids. MZ contained the highest contents of amino acids and their derivatives, phenolic acids and flavonoids. 26 key volatile compounds were considered as odor-active compounds. MZ showed the highest level of antioxidant and hypoglycemic activity. Statistics analysis indicated that polyphenols, flavonoids and catechins were significantly correlated (|r| ≥ 0.7, P < 0.05) with biological activities. This study indicated significant differences in the metabolic profiles of various types of Tibetan tea, which provided a clear database for quality detection of Tibetan tea.

Tuning self-assembly of amphiphilic sodium alginate-decorated selenium nanoparticle surfactants for antioxidant Pickering emulsion

Delivering effectively zero-valent selenium nanoparticles (SeNPs) and develop its functions in more fields is still a challenge. Herein, a novel template for the preparation and stabilization of SeNP-based surfactants was developed, amphiphilic sodium alginate (APSA), which can self-assemble into micelles in an aqueous solution. Primarily, physicochemical properties of SeNPs stabilized by APSA with different molecular weights were compared and the interaction mechanism of APSA/SeNPs was investigated. Moreover, a functional Pickering emulsion (PE) was presented using the SeNP-based surfactants. Results showed that high molecular weight-stabilized SeNPs had small particle size (54.72 nm) and great stability due to the hydrogen bonding between Se atoms and APSA. The "soft" particle-decorated SeNPs with interface activity formed a dense interfacial layer on the oil-water interface, which exhibited excellent antioxidant properties. The contents of lipid hydrogen peroxide (LH) and malondialdehyde (MDA) were significantly reduced by 88.7% and 63.4%. Overall, SeNPs stabilized by APSA have great application potential as an emulsifier and antioxidant in industrial field.

Structure and Bioactivities of a Novel Polysaccharide Extracted From Dendrobium huoshanense by Subcritical Water

In this study, the polysaccharide was extracted by subcritical water from Dendrobium huoshanense. A novel polysaccharide (DHPs-1) was obtained through several purification steps and its structure and bioactivity were investigated. Structural analysis indicated that the weight-average molecular weight of DHPs-1 was 5.0 × 10⁴ Da and it was mainly composed of glucose (65.04%), mannose (14.23%), galactose (8.17%), galacturonic acid (6.41%), rhamnose (2.34%), and xylose (1.25%). 1,4-Glcp, and 1,4,6-Galp were existed in the backbone of DHPs-1. The residues of 1,3,4-Galp, 1,4-Manp, 1,4-Galp, and 1,3,4,6-Galp could be in the backbone or the side chains with the non-reducing terminal of α-Manp. Bioactivity tests indicated that DHPs-1 had immunomodulatory activity in that it significantly enhanced transcript levels of cytokines [Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1β (IL-1β), and Interleukin-10 (IL-10)]. DPPH and hydroxyl radical scavenging tests showed that it had good antioxidant activity. These results reveal that DHPs-1 could be developed as a safe immunomodulatory agent and antioxidant for pharmacological or functional food applications.

Synthesis, characterization, in vitro antioxidant and hypoglycemic activities of selenium nanoparticles decorated with polysaccharides of Gracilaria lemaneiformis

Under a simple redox system of selenite and ascorbic acid, we used Gracilaria lemaneiformis polysaccharides (GLPs) as a stabilizer and dispersing agent to generate well-dispersed and stable selenium nanoparticles (SeNPs). The size, stability, morphology and physicochemical properties of GLPs-SeNPs were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FT-IR) spectra, energy dispersive X-ray (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric (TG). The results showed that orange-red, amorphous, zero-valent and spherical GLPs-SeNPs with mean diameter of approximately 92.5 nm were successfully prepared, which exhibited good storage stability at 4 °C and remaining highly stable at different ion strengths and pH. The 2,2-diphenyl-1-pycrylhydrazyl (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and superoxide anion radical (O₂^•-) radical scavenging ability of GLPs-SeNPs were higher than those of bare SeNPs, GLPs and sodium selenite (Na₂SeO₃), and could reach 103.41%, 94.23%, 86% at a concentration of 1.5 mg/mL, respectively. Besides, GLPs-SeNPs also showed higher inhibitory effects on α-amylase and α-glucosidase. In vitro cytotoxicity assay and hemolysis activity examinations indicated that GLPs-SeNPs have excellent biocompatibility. Therefore, the GLPs-SeNPs might be used as a potential antioxidant agent and antidiabetic agent for food and medical applications.

Characterization, Antioxidant and Antitumor Activities of Oligosaccharides Isolated from Evodia lepta (Spreng) Merr. by Different Extraction Methods

Evodia lepta (E. lepta) is a traditional Chinese herbal medicine with various biological activities. One of the active components of this widely used medicinal plant is believed to be an oligosaccharide. The extraction yields, structural characteristics, antioxidant, and antitumor activities of four oligosaccharide extracts obtained by hot water extraction (HEO), ultrasound-assisted extraction (UEO), enzyme-assisted (EEO), and microwave-assisted extraction (MEO) were investigated. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) results indicated that the extraction methods had a difference on the molecular mass distribution, structure, and morphology of the EOs. In addition, HEO and MEO showed strong antioxidant activities, which might be related to their uronic acid and protein contents. More interestingly, MEO was more active toward MDA-MB-231 cells compared to other cells, and cell growth inhibition was proposed to occur through apoptosis. Overall, microwave-assisted extraction is a promising technique for the extraction of high quality EO.