Preparation and characterization of Sargassum pallidum polysaccharide nanoparticles with enhanced antioxidant activity and adsorption capacity

Prebiotic characteristics of degraded polysaccharides from Acanthopanax senticosus polysaccharide on broilers gut microbiota based on in vitro digestion and fecal fermentation

This study aimed to evaluate the effect of low molecular weight Acanthopanax polysaccharides on simulated digestion, probiotics, and intestinal flora of broilers in vitro. The experiments were carried out by H2O2-Vc degradation of Acanthopanax polysaccharides, in vitro simulated digestion to evaluate the digestive performance of polysaccharides with different molecular weights, in vitro probiotic evaluation of the probiotic effect of polysaccharides on lactobacilli and bifidobacteria, in vitro anaerobic fermentation and high-throughput sequencing of 16S rRNA genes to study the impact of Acanthopanax polysaccharides on the intestinal flora of broilers, and the effect of Acanthopanax polysaccharides on the short-chain fatty acids of intestines were determined by GC-MS method. The results showed that the molecular weight of Acanthopanax polysaccharide (ASPS) was 9,543 Da, and the molecular weights of polysaccharides ASPS-1 and ASPS-2 were reduced to 4,288 Da and 3,822 Da after degradation, and the particle sizes, PDIs, and viscosities were also significantly decreased. ASPS-1 has anti-digestive properties and better in vitro probiotic properties. The addition of ASPS-1 regulates the structure of intestinal microorganisms by regulating fecalibacterium to produce short-chain fatty acids, promoting the colonization of beneficial bacteria such as fecalibacterium, paraprevotella and diminishing the prevalence of detrimental bacteria such as Fusobacteria. Interestingly the ASPS-1 group found higher levels of Paraprevotella, which degraded trypsin in the gut, reducing inflammation, acted as a gut protector, and was influential in increasing the levels of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and total SCFAs in the fermented feces. Therefore, the degraded ASPS-1 can better regulate the structure of intestinal flora and promote the production of SCFAs, creating possibilities for its use as a potential prebiotic, which is conducive to the intestinal health of poultry.

Purification and structural characterization of two polysaccharides with anti-inflammatory activities from Plumbago zeylanica L

Plumbago zeylanica L., a traditional Chinese medicine, has anti-bacterial and anti-inflammatory effects, and it is critical important to explore the chemical compounds and evaluate their biological actions from the medicinal plant. However, the chemical structure and biological activities of polysaccharides from P. zeylanica. were still poorly understood. In this study, two water-soluble polysaccharides named WPZP-2-1 and WPZP-2-2 were purified from P. zeylanica L. Chemical and spectroscopic tests showed that the main chain of WPZP-2-1 was →4)-α-D-GalpA-(1 → 2)-α-L-Rhap-(1→, and the branch chain was galactose or arabinose. The main chain of WPZP-2-2 was composed of →4)-α-D-GalpA-(1 → 2)-α-L-Rhap-(1→, and the O-2 and O-3 of →4)-α-D-GalpA had a small amount of acetylation. In addition, in vitro test showed that WPZP-2-1 and WPZP-2-2 significantly improved the inflammatory damage of LPS + IFN-γ-induced THP-1 cells via reducing the protein levels of CD14, TLR4 and MyD88, thereby promoting IL-10 expression and inhibiting the mRNA levels of TNF-α and IL-1β. Those findings indicated that WPZP-2-1 and WPZP-2-2 from the plant should be served as the potential anti-inflammatory agents.

Investigation of cellular uptake and transport capacity of Cordyceps sinensis exopolysaccharide‑selenium nanoparticles with different particle sizes in Caco-2 cell monolayer

Cordyceps sinensis exopolysaccharide‑selenium nanoparticles (EPS-SeNPs) were successfully constructed, characterized, and its Se release kinetics and mechanism were also evaluated in our previous studies. However, the intestinal cellular uptake and transport capacities of EPS-SeNPs remain unknown. On the basis of our previous researches, this work was designed to evaluate the uptake and transport capacities of EPS-SeNPs (EPS/Se = 20/1, 3/1, 1/1, and 3/4) in intestinal epithelial (Caco-2) cells. Confocal laser scanning microscopy results indicated that the internalization of coumarin-6 labeled EPS-SeNPs was in a time-dependent process and eventually located in the cytoplasm, not in the nucleus. Endocytosis inhibitors were employed to evaluate the cellular uptake pathway of EPS-SeNPs, relevant results revealed that clathrin-, caveolae-, and energy-mediated pathways were participated in the internalization of EPS-SeNPs by Caco-2 cells. In addition, the transportation of EPS-SeNPs across Caco-2 cell monolayers was in a concentration-dependent manner. Different particle sizes of EPS-SeNPs presented different uptake and transport capacities in Caco-2 cells. Noteworthy, EPS/Se = 3/4 with the highest selenium content possessed the most superior cellular uptake and transport abilities in Caco-2 cells. The present work may contribute to illustrate the internalization and transport mechanism of EPS-SeNPs, thus facilitating its application in food and medical industries.

Portulaca oleracea L. polysaccharide alleviates dextran sulfate sodium-induced ulcerative colitis by regulating intestinal homeostasis

Portulaca oleracea L. (purslane) is a vegetable that contains a variety of active compounds with nutritional properties and has the potential to treat ulcerative colitis (UC). However, the mechanisms underlying the effects of Portulaca oleracea L. polysaccharide (POP) in alleviating UC remain unclear. In this study, we prepared an aqueous extract of purslane and separated a fraction with molecular weight >10 kDa using membrane separation. This fraction was used to isolate POP. The effect of POP on gut microbiota and colon transcriptome in dextran sulfate sodium-induced UC model mice was evaluated. POP treatment reduced inflammation and oxidative stress imbalance in UC mice. In addition, POP improved the intestinal barrier and regulated intestinal homeostasis. Importantly, POP was found to regulate gut microbiota, maintain the levels of retinol and short-chain fatty acids in the gut, promote the proliferation and differentiation of B cells in the colon, and increase the expression of immunoglobulin A. These results provide novel insights into the role of POP in regulating intestinal homeostasis, which should guide further development of POP as a functional food.

Bergamot polysaccharides relieve DSS-induced ulcerative colitis via regulating the gut microbiota and metabolites

This study aimed to explore the efficacy of polysaccharides from bergamot (BP) in alleviating DSS-induced colitis. Results showed that BP was primarily composed of two components, BP-1 and BP-2, with similar monosaccharide compositions to BP (mainly glucose and xylose) and molecular weights (Mw) of 4.50 × 105 and 2.35 × 105 Da. This study found BP relieved disease symptoms such as weight loss and colon shortening in mice with colitis. Gut microbiota and metabolomics analysis revealed that the BP could also promote the proliferation of beneficial bacteria such as Bifidobacteria, Butyrivibrio, and Blautia, resulting in increased levels of SCFAs and L-phenylalanine, which were associated with phenylalanine, tyrosine, and tryptophan metabolism pathways. Further analysis validated the inflammatory activity of L-phenylalanine. Hence, BP may relieve colitis symptoms by regulating the gut microbiota and metabolism, which reduced inflammation and enhanced the expression of tight junctional proteins (TJ proteins) and mucin in the intestine.

Physicochemical properties and in vitro hypoglycemic activities of hsian-tsao polysaccharide fractions by gradient ethanol precipitation method

Hsian-tsao polysaccharides fractions (HPs), including HP20, HP40, HP60, and HP80, were fractioned by gradient precipitation of 20 %, 40 %, 60 %, and 80 % (v/v) ethanol, respectively. Their physicochemical properties and in vitro hypoglycemic activities (inhibitory activities on α-amylase and α-glucosidase, glucose adsorption capacity, and glucose diffusion retardation) were determined. The results showed that, with ethanol upward, the average particle size, molecular weight, and apparent viscosity of HPs were decreased while carbohydrate and uronic acid contents, absolute zeta potential, and thermal stability were increased. Each of the HPs contained Rha, Ara, Gal, Xyl, Man, and GalA with different molar ratios, indicative of anionic heteropolysaccharides with uronic acid. HPs, with diverse structures and surface morphologies as proved by FTIR and SEM, whose solutions were pseudoplastic fluids, exhibited elastic behavior of weak gel networks at concentrations of >1 %. Moreover, HPs showed inhibitory activities on α-amylase and α-glucosidase, of which HP80 was the strongest. For α-amylase, HP20 and HP60 behaved as mixed inhibitors, while HP40 and HP80 were non-competitive. For α-glucosidase, HPs acted as mixed inhibitors. Additionally, HPs possessed glucose adsorption capacity and glucose diffusion retardation, with the best for HP20. These results suggested that HPs possessed hypoglycemic activities, which could be developed as functional food or hypoglycemic drugs.

Formation Optimization, Characterization and Antioxidant Activity of Auricularia auricula-judae Polysaccharide Nanoparticles Obtained via Antisolvent Precipitation

Auricularia auricula-judae polysaccharide (AAP)-based nanoparticles (NPs) prepared via an anti-solvent precipitation approach were studied. Response surface methodology (RSM) design was carried out on the basis of single factor experiments, using average size and polydispersity index (PDI) as indicators. The optimal preparation conditions were determined to include an AAP concentration of 1 mg/mL, a pH of 8, and an anti-solvent/solvent volume ratio of 6. The average particle sizes of the AAP-NPs, PDI and electrical characteristic (ζ-potential) were found to be 150.27 ± 3.21 nm, 0.135 ± 0.012 and -31.10 ± 0.52 mV, respectively. Furthermore, Fourier transform infrared spectroscopy (FTIR) was used to determine the chemical structure of the AAP-NPs. It was observed that the intensity of AAP-NPs in the wide spectral band of 3000-3750 cm^-1 was significantly stronger than that of the AAP, as was the characteristic peak of carboxyl anion, and the characteristic band moved to shorter wavelengths. Subsequent thermogravimetric analysis showed that the antisolvent precipitation method improved the thermal stability of the AAP, while scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed that the morphology of AAP-NPs was uniform and well-distributed, and that their single crystal structures had remained unaffected during the process. Moreover, the DPPH and ABTS scavenging activities of AAP-NPs were increased, and the IC50 values were 0.544 ± 0.241 mg/mL and 0.755 ± 0.226 mg/mL, respectively.