Structural characterization of a soluble polysaccharide SSPS1 from soy whey and its immunoregulatory activity in macrophages

Structural characterization and mechanisms of macrophage immunomodulatory activity of a novel polysaccharide with a galactose backbone from the processed Polygonati Rhizoma

A purified polysaccharide with a galactose backbone (SPR-1, Mw 3,622 Da) was isolated from processed Polygonati Rhizoma with black beans (PRWB) and characterized its chemical properties. The backbone of SPR-1 consisted of [(4)-β-D-Galp-(1]9 → 4,6)-β-D-Galp-(1 → 4)-α-D-GalpA-(1 → 4)-α-D-GalpA-(1 → 4)-α-D-Glcp-(1 → 4,6)-α-D-Glcp-(1 → 4)-α/β-D-Glcp, with a branch chain of R1: β-D-Galp-(1 → 3)-β-D-Galp-(1→ connected to the →4,6)-β-D-Galp-(1→ via O-6, and a branch chain of R2: α-D-Glcp-(1 → 6)-α-D-Glcp-(1→ connected to the →4,6)-α-D-Glcp-(1→ via O-6. Immunomodulatory assays showed that the SPR-1 significantly activated macrophages, and increased secretion of NO and cytokines (i.e., IL-1β and TNF-α), as well as promoted the phagocytic activities of cells. Furthermore, isothermal titration calorimetry (ITC) analysis and molecular docking results indicated high-affinity binding between SPR-1 and MD2 with the equilibrium dissociation constant (K D) of 18.8 μM. It was suggested that SPR-1 activated the immune response through Toll-like receptor 4 (TLR4) signaling and downstream responses. Our research demonstrated that the SPR-1 has a promising candidate from PRWB for the TLR4 agonist to induce immune response, and also provided an easily accessible way that can be used for PR deep processing.

Protective effect of Broussonetia papyrifera leaf polysaccharides on intestinal integrity in a rat model of diet-induced oxidative stress

This study aimed to investigate the effect of Broussonetia papyrifera polysaccharides (BPP) on the jejunal intestinal integrity of rats ingesting oxidized fish oil (OFO) induced oxidative stress. Polysaccharides (Mw 16,956 Da) containing carboxyl groups were extracted from Broussonetia papyrifera leaves. In vitro antioxidant assays showed that this polysaccharide possessed antioxidant capabilities. Thirty-two male weaned rats were allocated into two groups orally infused BPP solution and PBS for 26 days, respectively. From day 9 to day 26, half of the rats in each group were fed food containing OFO, where the lipid peroxidation can induce intestinal oxidative stress. OFO administration resulted in diarrhea, decreased growth performance (p < 0.01), impaired jejunal morphology (p < 0.05) and antioxidant capacity (p < 0.01), increased the levels of ROS and its related products, IL-1β and IL-17 (p < 0.01) of jejunum, as well as down-regulated Bcl-2/Bax (p < 0.01) and Nrf2 signaling (p < 0.01) of jejunum in rats. BPP gavage effectively alleviated the negative effects of OFO on growth performance, morphology, enterocyte apoptosis, antioxidant capacity and inflammation of jejunum (p < 0.05) in rats. In the oxidative stress model cell assay, the use of receptor inhibitors inhibited the enhancement of antioxidant capacity by BPP. These results suggested that BPP protected intestinal morphology, thus improving growth performance and reducing diarrhea in rats ingesting OFO. This protective effect may be attributed to scavenging free radicals and activating the Nrf2 pathway, which enhances antioxidant capacity, consequently reducing inflammation and mitigating intestinal cell death.

Ultrasound-assisted polysaccharide extraction from Fritillaria ussuriensis Maxim. and its structural characterization, antioxidant and immunological activity

Fritillaria ussuriensis Maxim. (F.M.) has been widely used in both food and medication for more than 2000 years. In order to achieve its comprehensive utilization and investigate the structural characterization and biology activity, response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction conditions of F.M. polysaccharides. The optimal extraction conditions were ultrasonic power of 174.2 W, ratio of liquid to material of 40.7 mL/g and ultrasonic time of 82.0 min. In addition, a neutral polysaccharide F-1 was obtained, and its structure characterization, antioxidant and immunological activity were evaluated. The structural properties of the polysaccharide were characterized by UV, IR, GC-MS, NMR and AFM. Monosaccharide composition of F-1 (MW 18.11 kDa) was rhamnose, arabinose, glucosamine hydrochloride, galactose, and glucose which under the ratio of 0.9: 3.8: 0.2: 2.9: 92.2. The fractions of F-1 were mainly linked by → 6)-α-D-Glcp-(1 → with branch chain α-D-Glcp-(1 → 4)-α-D-Glcp-(1 → and 4,6)-α-D-Glcp-(1 → residues. Moreover, F-1 has a significant scavenging activity, which can clear hydroxyl radicals, superoxide anion, DPPH and ABTS. In addition, the immunological activity showed that F-1 had an effect on macrophage phagocytic activity. And it can increase the release of inflammatory factors including TNF-α, IL-1β and IL-6. F-1 is a novel polysaccharide with significant activity in antioxidant and immunological activity, which has great potential for antioxidant and immunizer in food, pharmaceutical and cosmetic industries. The study can provide a methodological basis for polysaccharide research and theoretical basis for the industrialized production and practical application.

Polysaccharides from banana (Musa spp.) blossoms: Isolation, identification and anti-glycation effects

Musa spp. (banana) is consumed globally as a healthy fruit and improves the immune system. Banana blossoms are a by-product of banana harvesting rich in active substances such as polysaccharides and phenolic compounds; however, these blossoms are typically discarded as waste. In this report, a polysaccharide, MSBP11, was extracted, purified and identified from banana blossoms. MSBP11 is a neutral homogeneous polysaccharide with a molecular mass of ∼214.43 kDa and composed of arabinose and galactose at a ratio of 0.303:0.697. MSBP11 exhibited potent antioxidant and anti-glycation activities in a dose-dependent manner and can be used as a potential natural antioxidant and inhibitor of advanced glycosylation end products (AGEs). In addition, banana blossoms have been shown to decrease the levels of AGEs in chocolate brownies, which might possibly be developed as functional foods for diabetic patients. This study provides a scientific basis to further research the potential application of banana blossoms in functional foods.

Comparative Study on the Structural Properties and Bioactivities of Three Different Molecular Weights of Lycium barbarum Polysaccharides

The molecular weight, the triple-helix conformation, the monosaccharide content, the manner of glycosidic linkages, and the polysaccharide conjugates of polysaccharides all affect bioactivity. The purpose of this study was to determine how different molecular weights affected the bioactivity of the Lycium barbarum polysaccharides (LBPs). By ethanol-graded precipitation and ultrafiltration membrane separation, one oligosaccharide (LBPs-1, 1.912 kDa) and two polysaccharides (LBPs-2, 7.481 kDa; LBPs-3, 46.239 kDa) were obtained from Lycium barbarum. While the major component of LBPs-1 and LBPs-2 was glucose, the main constituents of LBPs-3 were arabinose, galactose, and glucose. LBPs-2 and LBPs-3 exhibited triple-helix conformations, as evidenced by the Congo red experiment and AFM data. Sugar residues of LBPs-2 and LBPs-3 were elucidated by NMR spectra. The polysaccharides (LBPs-2 and LBPs-3) exhibited much higher antioxidant capacities than oligosaccharide (LBPs-1). LBPs-3 showed higher oxygen radical absorbance capacity (ORAC) and superoxide dismutase (SOD) activity than LBPs-2, but a lower capability for scavenging ABTS⁺ radicals. In zebrafish, LBPs-2 and LBPs-3 boosted the growth of T-lymphocytes and macrophages, enhanced the immunological response, and mitigated the immune damage generated by VTI. In addition to the molecular weight, the results indicated that the biological activities would be the consequence of various aspects, such as the monosaccharide composition ratio, the chemical composition, and the chemical reaction mechanism.

Chemical Characterization and Immunomodulatory Activity of Fucoidan from Sargassum hemiphyllum

Fucoidan is a sulfated algal polyanionic polysaccharide that possesses many biological activities. In this paper, a fucoidan (SHF) polysaccharide was extracted from Sargassum hemiphyllum collected in the South China Sea. The SHF, with a molecular weight of 1166.48 kDa (44.06%, w/w), consisted of glucose (32.68%, w/w), galactose (24.81%, w/w), fucose (20.75%, w/w), xylose (6.98%, w/w), mannose (2.76%, w/w), other neutral monosaccharides, and three uronic acids, including glucuronic acid (5.39%, w/w), mannuronic acid (1.76%, w/w), and guronuronic acid (1.76%, w/w). The SHF exhibited excellent immunostimulatory activity. An immunostimulating assay showed that SHF could significantly increase NO secretion in macrophage RAW 264.7 cells via upregulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) levels based on both gene expression and protein abundance. These results suggest that SHF isolated from Sargassum hemiphyllum has great potential to act as a health-boosting ingredient in the pharmaceutical and functional-food fields.

Isolation, Characterization and Immunomodulatory Activity Evaluation of Chrysolaminarin from the Filamentous Microalga Tribonema aequale

The aim of this study is to investigate the differences in the accumulation capacity of chrysolaminarin among six Tribonema species and to isolate this polysaccharide for immunomodulatory activity evaluation. The results showed that T. aequale was the most productive strain with the highest content and productivity of chrysolaminarin, which were 17.20% (% of dry weight) and 50.91 mg/L/d, respectively. Chrysolaminarin was then extracted and isolated from this alga, and its monosaccharide composition was mainly composed of a glucose (61.39%), linked by β-D-(1→3) (main chain) and β-D-(1→6) (branch chain) glycosidic bonds, with a molecular weight of less than 6 kDa. In vitro immunomodulatory assays showed that it could activate RAW264.7 cells at a certain concentration (1000 μg/mL), as evidenced by the increased phagocytic activity and upregulated mRNA expression levels of IL-1β, IL6, TNF-α and Nos2. Moreover, Western blot revealed that this polysaccharide stimulated the phosphorylation of p-65, p-38 and JNK in NF-κB and MAPK signaling pathways. Overall, these findings provide a reference for the further development and utilization of algae-based chrysolaminarin, while also offering an in-depth understanding of the immunoregulatory mechanism.

Natural Deep Eutectic Solvent-Assisted Extraction, Structural Characterization, and Immunomodulatory Activity of Polysaccharides from Paecilomyces hepiali

Polysaccharides, which can be affected by different preparations, play a crucial role in the biological function of Paecilomyces hepiali (PHPS) as a health food. To explore high-valued polysaccharides and reduce the negative influence of human involvement, a green tailorable deep eutectic solvent (DES) was applied to optimize the extraction of polysaccharides (PHPS-D), followed by the evaluation of the structural properties and immunomodulation by comparison with the hot-water method (PHPS-W). The results indicated that the best system for PHPS-D was a type of carboxylic acid-based DES consisting of choline chloride and succinic acid in the molar ratio of 1:3, with a 30% water content. The optimal condition was as follows: liquid-solid ratio of 50 mL/g, extraction temperature of 85 °C, and extraction time of 1.7 h. The actual PHPS-D yield was 12.78 ± 0.17%, which was obviously higher than that of PHPS-W. The structural characteristics suggested that PHPS-D contained more uronic acid (22.34 ± 1.38%) and glucose (40.3 ± 0.5%), with a higher molecular weight (3.26 × 10⁵ g/mol) and longer radius of gyration (78.2 ± 3.6 nm), as well as extended chain conformation, compared with PHPS-W, and these results were confirmed by AFM and SEM. Immunomodulatory assays suggested that PHPS-D showed better performance than PHPS-W regarding pinocytic activity and the secretion of NO and pro-inflammatory cytokines (IL-6, TNF-α and IL-1β) by activating the corresponding mRNA expression in RAW264.7 cells. This study showed that carboxylic acid-based DES could be a promising tailorable green system for acidic polysaccharide preparation and the valorization of P. hepiali in functional foods.