In vitro fermentation characteristics of polysaccharides from coix seed and its effects on the gut microbiota.

Coix seed polysaccharides had received increasing attention due to their diverse biological activities. In this study, a homogeneous polysaccharide (CSPW) was extracted and purified from coix seed. Furthermore, the saliva-gastrointestinal digestion and fecal fermentation behavior of CSPW were simulated in vitro. The results showed that CSPW was mainly composed of glucose. It cannot be degraded by the simulated salivary and intestinal digestive system, but can be degraded by the simulated gastric digestive system. After fermentation for 24 h, CSPW promoted the production of short-chain fatty acids (SCFAs), with acetic acid, propionic acid and n-butyric acid being the main metabolites. In addition, CSPW could significantly regulate the composition and microbial diversity of gut microbiota by increasing the relative abundance of beneficial bacteria, such as Limosilicactobacillus, Bifidobacterium and Collinsella. Finally, further analysis of functional prediction revealed that amino acid metabolism, nucleotide metabolism and carbohydrate metabolism were the most important pathways for CSPW to promote health. In summary, our findings suggested that CSPW could potentially be used as a good source of prebiotics because it can be used by gut microbiota to produce SCFAs and regulate the gut microbiota.

Preparation Process Optimization of Peptides from Agaricus blazei Murrill, and Comparison of Their Antioxidant and Immune-Enhancing Activities Separated by Ultrafiltration Membrane Technology.

Agaricus blazei murrill (ABM), a large fungus, is reported to have extensive biological activities but the antioxidant and immune-regulatory capacities have been less studied and the components responsible for the functions are unclear. This study prepared ABM peptides (ABMP) using ultrasound-assisted enzymatic extraction (UAEE) strategy and cascade ultrafiltration (UF) membrane technology. The UAEE extraction conditions were optimized using response surface methodology (RSM) with four factors and three levels to achieve the maximum ABMP yield (34.03%); the optimal conditions were an enzyme amount of 4%, ratio of ABM to water of 1:30, ultrasonic power of 360 W, and ultrasonic time of 30 min. Four ABMP fractions were obtained after UF with different pore size and their antioxidant and immune-regulatory abilities were evaluated and compared. The results showed that they could effectively scavenge DPPH, hydroxyl, and ABTS radicals, especially for ABMP-2; the scavenging rate of the above radicals were 79.31%, 63.60%, and 96.08%, respectively. In addition, four ABMP fractions also activated macrophage activity through strengthening phagocytosis and the production of NO, IL-6, IL-1ß, and TNF-α in a dose-dependent manner. Notably, the ABMP-2 fraction with a MW of 3-5 kDa and peptide purity of 82.88% was found to have the best effect, showing the maximum phagocytosis (189.37%) as well as NO (7.98 µM), IL-6 (195.05 pg/mL), IL-1ß (876.15 pg/mL), and TNF-α (1620 pg/mL) secretion at a treatment concentration of 150 µg/mL. The findings indicated that the ABMP, especially for the separate ABMP-2, could be used as dietary supplements and have the potential to be exploited as immune-enhancing agents.

Formation of sweet potato starch nanoparticles by ultrasonic-assisted nanoprecipitation: Effect of cold plasma treatment.

Starch nanoparticles (SNPs) were produced from sweet potato starches by ultrasonic treatment combined with rapid nanoprecipitation. The starch concentration, ultrasonic time, and the ratio of starch solution to ethanol were optimized through dynamic light scattering (DLS) technique to obtain SNPs with a Z-average size of 64.51 ± 0.15 nm, poly dispersity index (PDI) of 0.23 ± 0.01. However, after freeze drying, the SNPs showed varying degrees of aggregation depending on the particle size of SNPs before freeze-drying. The smaller the particle size, the more serious the aggregation. Therefore, we tried to treat SNPs with dielectric barrier discharge cold plasma before freeze drying. Properties including morphological features, crystalline structure and apparent viscosity of various starches were measured by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and rheometer, respectively. The results showed that, after cold plasma (CP) treatment, the aggregation of SNPs during freeze drying was significantly inhibited. Compared to the native sweet potato starch, SNPs showed a higher relative crystallinity and a lower apparent viscosity. After CP treatment, the relative crystallinity of CP SNPs was further higher, and the apparent viscosity was lower. This work provides new ideas for the preparation of SNPs and could promote the development of sweet potato SNPs in the field of active ingredient delivery.

Physicochemical properties and immune-enhancing activity of graded polysaccharides from the peels of stem lettuce (Lactuca sativa) by cascade membrane technology.

In this study, cascade membrane technology was applied to classify polysaccharides from the peels of stem lettuce (PPSLs), and three graded polysaccharides (PPSL100, PPSL10, and PPSL1) were obtained using ultrafiltration membranes of 100, 10, and 1 kDa in sequence. The physicochemical properties and immune-modulatory activity of three PPSLs fractions were analyzed and compared. Results showed that all three fractions have characteristic absorption peak of polysaccharides determined by FT-IR, and their monosaccharide composition only consisted of glucose determined by HPLC. PPSL10 had the highest contents of total sugar (88.09 ± 3.52%), uronic acid (2.55 ± 0.10%), and sulfate group (4.15 ± 0.20%). Besides, all three fractions exhibited immune-enhancing activities using RAW264.7 macrophages model, and PPSL10 was the best able to promote phagocytosis of neutral red and nitric oxide generation, which might relate to the high contents of above compositions and medium molecular weight (32 kDa). The findings indicated that PPSL10 could be developed as immune-modulator in the field of functional foods.

Solid-state-cultured mycelium of Antrodia camphorata exerts potential neuroprotective activities against 6-hydroxydopamine-induced toxicity in PC12 cells.

Antrodia camphorata (A. camphorata) is an edible fungus containing various bioactive compounds generally used for health benefits. This study aimed to explore the potential neuroprotective activities of solid-state-cultured mycelium of A. camphorata (SCMAC) against Parkinson's disease (PD), as well as the underlying mechanism using an in vitro 6-hydroxydopamine (6-OHDA)-induced PC12 cell model. The results showed that SCMAC extracts alleviated cell toxicity induced by 6-OHDA and the loss of dopaminergic neurons, which was confirmed by the increase of cell viabilities, inhibition of cell apoptosis, the upregulation of tyrosine hydroxylase (TH) and dopamine transporter (DAT) levels and the downregulation of α-Synuclein level. After purification, 11 compounds were identified by the NMR technique, including a quinone, four phenolic acid derivatives, three ubiquinone derivatives, two alkaloids, and a triterpenoid. The present study suggests that SCMAC could be an attractive candidate for the prevention or treatment of PD. PRACTICAL APPLICATIONS: Parkinson's disease seriously affects the lifetime and quality of the elder population for a long history. Long-term consumption of L-DOPA will result in side effects, such as developing abnormal involuntary movements called dyskinesia. This study showed that natural SCMAC extracts could be a potential therapeutic agent for the treatment of neurodegenerative disorder.

SPRY4-AS1, A Novel Enhancer RNA, Is a Potential Novel Prognostic Biomarker and Therapeutic Target for Hepatocellular Carcinoma.

A growing number of evidence have demonstrated the involvement of enhancer RNAs (eRNAs) in tumor progression. However, the possible functions of eRNAs in hepatocellular carcinoma (HCC) remain largely unclear. Our present research aimed to screen critical eRNAs and to further delve into the clinical significance of eRNAs in HCC patients. In this study, we identified 124 prognosis-related eRNAs by analyzing The Cancer Genome Atlas (TCGA) datasets. Among them, SPRY4 antisense RNA 1 (SPRY4-AS1) may be a key eRNA involved in HCC progression. SPRY4 was a regulatory target of SPRY4-AS1. High SPRY4-AS1 expression was associated with poor prognosis of HCC patients. Kyoto Encyclopedia of Genes and Genomes (KEGG) assays revealed that the mainly enriched biological process included Human papillomavirus infection, Hippo signaling pathway, and Proteoglycans in cancer. Besides, RT-PCR and immunohistochemical staining confirmed SPRY4-AS1 as an overexpressed eRNA in HCC specimens. The pan-cancer assays revealed that SPRY4-AS1 was associated with glioblastoma multiforme (GBM), adrenocortical carcinoma (ACC), brain lower grade glioma (LGG) and mesothelioma(MESO). Positive associations were observed between SPRY4-AS1 and SPRY4 (its target gene) in 16 tumor types. Collectively, our findings reveal a novel eRNA SPRY4-AS1 for HCC progression and suggest that SPRY4-AS1 may be a potential biomarker and therapeutic target for HCC.

Anti-Inflammatory Effects of Mytilus coruscus Polysaccharide on RAW264.7 Cells and DSS-Induced Colitis in Mice.

Considerable literature has been published on polysaccharides, which play a critical role in regulating the pathogenesis of inflammation and immunity. In this essay, the anti-inflammatory effect of Mytilus coruscus polysaccharide (MP) on lipopolysaccharide-stimulated RAW264.7 cells and a dextran sulfate sodium (DSS)-induced ulcerative colitis model in mice was investigated. The results showed that MP effectively promoted the proliferation of RAW264.7 cells, ameliorated the excessive production of inflammatory cytokines (TNF-α, IL-6, and IL-10), and inhibited the activation of the NF-κB signaling pathway. For DSS-induced colitis in mice, MP can improve the clinical symptoms of colitis, inhibit the weight loss of mice, reduce the disease activity index, and have a positive effect on the shortening of the colon caused by DSS, meliorating intestinal barrier integrity and lowering inflammatory cytokines in serum. Moreover, MP makes a notable contribution to the richness and diversity of the intestinal microbial community, and also regulates the structural composition of the intestinal flora. Specifically, mice treated with MP showed a repaired Firmicutes/Bacteroidetes ratio and an increased abundance of some probiotics like Anaerotruncus, Lactobacillus, Desulfovibrio, Alistipe, Odoribacter, and Enterorhabdus in colon. These data suggest that the MP could be a promising dietary candidate for enhancing immunity and protecting against ulcerative colitis.

Effects of ultrasonic pre-treatment on physicochemical properties of proteins extracted from cold-pressed sesame cake.

Sesame is an oil crop with high nutritional value. Protein is one of the main ingredients of sesame, however research on protein of cold-pressed sesame cake is limited. This study aimed to investigate the effects of ultrasonic pre-treatment (UPT) on physicochemical properties of proteins (yield, solubility, amino acid composition, surface properties, structural and thermal stability) extracted from the cold-pressed sesame cake, after removing lignans by ultrasonic-assisted extraction. By comparison, the extraction yield of protein was significantly (p ＜ 0.05) increased from 22.24% (without UPT) to 25.95% (with UPT), while the purity (54.08% without UPT, 55.43% with UPT), total amount of essential amino acids (22.48% without UPT, 23.10% with UPT) and non-essential amino acids (37.48% without UPT, 36.54% with UPT) were not significantly influenced. Besides, UPT slightly reduced the solubility, foaming capacity and stability (FC and FS) of protein. In addition, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermal stability (TG) analysis demonstrated that UPT could disorder and loose protein molecular structure, resulting in the change of morphology, secondary structure and thermal stability. In conclusion, this study provides a way for the separation and future application of sesame cake protein. UPT is a good option to remove the lignans from sesame cake proteins.

Orbitides isolated from flaxseed induce apoptosis against SGC-7901 adenocarcinoma cells.

Unique plant-derived cyclic peptides family exhibiting various key biological activities has great possibility for anticancer therapy. In this study, we investigated the effects of orbitides isolated from flax (Linum usitatissimum L.) on the growth of SGC-7901 cancer cells and the potential mechanism. Results showed that flaxseed orbitides killed off cancer cells by inducing apoptosis in a dose-dependent manner, which was confirmed by the appearance of nuclear shrinkage and DNA fragmentation, and the inhibitory effect was stronger than that of pure orbitide [1-9-NαC]-linusorb B2 or [1-9-NαC]-linusorb B3. Besides, the mitochondrial apoptosis pathway-related protein cytochrome C (Cyt C) was released from mitochondria to cytosol, associated with the activation of caspases 9 and 3, and the cleavage of PARP. Taken together, these results indicated that flaxseed orbitides induced apoptosis via the mitochondrial pathway, releasing Cyt C, increasing Bax/Bcl-2 ratio and elevating the expression of cleaved caspase 9 and 3 in SGC-7901 cells.

Protective effect of seleno-amino-oligosaccharide on oxidative damage of IPEC-1 cells by activating Keap1/Nrf2 signaling pathway.

The aim of the study was to investigate the antioxidant effect of seleno-amino-oligosaccharide (Se-AOS) on intestinal porcine epithelial cells (IPEC-1). MTT assay showed that Se-AOS had no effect on the viability of IPEC-1 cells up to a concentration of 9200 µg/L and Se-AOS significantly increased the viability of IPEC-1 cells compared to cells exposed to H2O2 alone. Se-AOS significantly increased the level of superoxide Dismutase (SOD) and decreased the levels of malonic dialdehyde (MDA) and lactate dehydrogenase (LDH) in IPEC-1 cells. The gene expression levels of different antioxidant enzymes dramatically increased by the pretreatment of Se-AOS compared to H2O2 treatment. In addition, the results indicated that Se-AOS up-regulated the intracellular Nrf2 and down-regulated the level of Keap1 by western blot. Taken together, these findings suggested that Se-AOS can protect IPEC-1 cells from oxidative damage through activating the Keap1/Nrf2 signaling pathway.

Chemically modified polysaccharides: Synthesis, characterization, structure activity relationships of action.

Polysaccharides are a major class of biomacromolecules. Their bioactivities depend on chemical structure, which includes monosaccharide composition, linkages below sugar residues, and solution conformation. Many researchers report that chemical modifications of polysaccharides lead to a significantly increase in the structural diversity, promoting bioactivity and even add new bioactivities, including antioxidant and anti-tumor properties as well as anticoagulant and immunoregulatory activities. This paper reviews the recent progress of chemical modification of polysaccharides, including i) the common synthetic methods of chemical modification; ii) their structural characterization; iii) their bioactivities; and iv) the structure activity relationships of these modified polysaccharides. This review also suggests future directions for researchers and new applications for chemically modified polysaccharide derivatives in the pharmaceutical and food industries.

Antibacterial Activity and Mechanisms of Essential Oil from Citrus medica L. var. sarcodactylis.

In this work, antibacterial activity of finger citron essential oil (FCEO, Citrus medica L. var. sarcodactylis) and its mechanism against food-borne bacteria were evaluated. A total of 28 components in the oil were identified by gas chromatography-mass spectrometry, in which limonene (45.36%), γ-terpinene (21.23%), and dodecanoic acid (7.52%) were three main components. For in vitro antibacterial tests, FCEO exhibited moderately antibacterial activity against common food-borne bacteria: Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Micrococcus luteus. It showed a better bactericidal effect on Gram-positive bacteria than Gram-negative. Mechanisms of the antibacterial action were investigated by observing changes of bacteria morphology according to scanning electron microscopy, time-kill analysis, and permeability of cell and membrane integrity. Morphology of tested bacteria was changed and damaged more seriously with increased concentration and exposure time of FCEO. FCEO showed a significant reduction effect on the growth rate of surviving bacteria and lead to lysis of the cell wall, intracellular ingredient leakage, and consequently, cell death.

Structure, bioactivities and applications of the polysaccharides from Tremella fuciformis mushroom: A review.

Tremella fuciformis is an important edible mushroom that has been widely cultivated and used as food and medicinal ingredient in traditional Chinese medicine. In the past decades, many researchers have reported that T. fuciformis polysaccharides (TPS) possess various bioactivities, including anti-tumor, immunomodulatory, anti-oxidation, anti-aging, repairing brain memory impairment, anti-inflammatory, hypoglycemic and hypocholesterolemic. The structural characteristic of TPS has also been extensively investigated using advanced modern analytical technologies such as NMR, GC-MS, LC-MS and FT-IR to dissect the structure-activity relationship (SAR) of the TPS biomacromolecule. This article reviews the recent progress in the extraction, purification, structural characterization and applications of TPS.

Structure and chain conformation of a neutral polysaccharide from sclerotia of Polyporus umbellatus.

A water-soluble heteropolysaccharide (PUP60W-1) was purified from the hot water extract of sclerotia of P. umbellatus by chromatography with DEAE Sepharose Fast Flow and Sephacryl S200 High-Resolution. The primary structure of PUP60W-1 was elucidated by GC, GC-MS and NMR. PUP60W-1 was identified as a highly branched polysaccharide composed of fucose, glucose and galactose in a ratio of 1.0:0.9:13.3. The main repeating unit was identified as α-(1→6)-d-galactopyranan backbone with substitution of terminal α-galactopyranosyl residues at O-2 for two out of every three main chain galactose residues. Its chain conformation was studied by atom force microscopy and size exclusion chromatography coupled with multiple detectors. The results revealed that PUP60W-1 had a molecular weight of 2.47×104Da with a polydispersity index of 1.04, and existed in water as compact sphere structures which could be disrupted into smaller spherical chain blocks after dispersion with sodium dodecyl sulfate.

Structure elucidation and antioxidant activity of a novel polysaccharide from Polyporus umbellatus sclerotia.

A novel water-soluble polysaccharide PUP60S2, with a molecular weight of 1.44×10(4)Da, was obtained from the sclerotia of Polyporus umbellatus by hot water extraction, ethanol precipitation, anion-exchange and size-exclusion chromatography. PUP60S2 was a polysaccharide comprised of about 22.3% glucuronic acid. Monosaccharide composition analysis showed that PUP60S2 was only comprised of glucose and glucuronic acid. Reduction of carboxyl groups, sugar analysis, methylation analysis, together with one and two dimension NMR spectra disclosed that the backbone of PUP60S2 consisted of (1→6)-ß-d-glucopyranosyl, every second of which was substituted at O-3 by side chains consisting of terminal ß-d-Glcp, (1→3)-ß-d-Glcp, (1→3)-ß-d-GlcpA, (1→4)-ß-d-Glcp and (1→4)-ß-d-GlcpA units. The antioxidant activity assay in vitro showed that PUP60S2 exerted a significant scavenging effect on DPPH, hydroxyl radical and superoxide radical in a dose-dependent manner.

Extraction, Antimicrobial, and Antioxidant Activities of Crude Polysaccharides from the Wood Ear Medicinal Mushroom Auricularia auricula-judae (Higher Basidiomycetes).

In this study, crude polysaccharides of culinary-medicinal mushroom Auricularia auricular-judae were extracted by hot water extraction and alcohol precipitation, and their antimicrobial and antioxidant activities were investigated. An optimum extraction condition was obtained at a ratio of liquid to solid 70 mL/g, temperature 90°C, time 4 h and extraction number 4. Accordingly, the best yield of crude polysaccharides was 6.89% with 76.12% in purity. Some bacteria and fungi were used for antimicrobial studies. It was found that crude A. auricula-judae had great antimicrobial activities against Escherichia coli and Staphylococcus aureus, but no activities on the others. The inhibitory diameters of antimicrobial zones for the two were 5.55 ± 0.182 and 9.84 ± 0.076 mm, respectively. Moreover, crude A. auricula-judae had significant antioxidant activities in scavenging free radicals, reducing power assays, and Fe2+ chelating ability assay. Results revealed that crude A. auricula-judae has a great potential as antimicrobial and antioxidant, and it can be a supplementary food for human health.

Effect of quaternization degree on physiochemical and biological activities of chitosan from squid pens.

Chitosan was prepared by alkaline N-deacetylation of ß-chitin from squid pens, and N-(2-hydroxy) propyl-3-trimethyl ammonium chitosan chloride (HTCC) derivatives, with different degrees of quaternization (DQ) ranging from 0.77 to 1.06, were synthesized. It was identified by FT-IR, 1H NMR and XRD analysis. All of the HTCC showed good water solubility in a wide pH range. The moisture absorption and retention abilities of all the HTCC were much better than that of the chitosan. The moisture absorption and retention values of all the HTCC at 43% RH for 24 h were above 49% and 92%, respectively. The scavenging ability of HTCC against hydroxyl and ABTS radicals improved with increasing concentration. The effectiveness of HTCC against hydroxyl radicals was lower than that of chitosan. These results indicated that HTCC, which has a much better moisture absorption and retention capacity, may act as a potential moisturizer in vitro.

Effects of hydroxypropyl degree on physiochemical activities of chitosan from squid pens.

Chitosan was prepared by alkaline N-deacetylation of ß-chitin and hydroxypropyl derivatives with different degrees of substitution (DS) were synthesized. It was characterized by Fourier transform infrared (FT-IR) and elemental analysis. The DS of hydroxypropyl chitosan (HPCS) calculated by an element analyzer were 0.42, 0.75, 1.20, 1.82 and 2.25. HPCS showed better foam capacity and stability than that of chitosan, and the effectiveness correlated well with the DS of HPCS. The highest bile acid-binding capacity of all five HPCS reached 56.02 mg/g, which was 4.0-fold higher than that of chitosan. The scavenging ability of HPCS against hydroxyl and ABTS radicals improved with increasing concentration. The correlation between the hydroxypropyl content (DS) of HPCS and scavenging ABTS radical ability was positive. The hydroxyl radicals scavenging activity of HPCS correlated well with its increasing concentration, and EC50 values were below 12.5 mg/mL. These results indicated that hydroxypropylation is a possible approach to obtain chitosan derivatives with desirable physiochemical properties.

Structural investigation of a novel heteropolysaccharide from the fruiting bodies of Boletus edulis.

A novel water-soluble heteropolysaccharide, BEPF1, was isolated from the fruiting bodies of Boletus edulis with boiling water extraction and purified by Sephacryl S-300, with a molecular weight of 1.08×10(4)Da. Sugar composition of BEPF1 showed that it was composed of l-fucose, d-mannose, d-glucose and d-galactose in the ratio of 0.21:0.23:1.17:1.00. Methylation analysis together with (1)H, (13)C and 2D NMR spectroscopy established that BEPF1 was consisted of α-d-(1→6)-galactopyranan backbone with a terminal of α-l-fucosyl unit on O-2 of the 2-d-(2→6)-galactosyl units, ß-d-(1→6)-4-O-Me-glucopyranan and ß-d-(1→6)-glucopyranan backbone with a terminal ß-d-glucosyl unit and it also contained a minor of 2,6-ß-d-Mannopyranan residues.

Structural elucidation of a novel water-soluble fructan isolated from Wedelia prostrata.

A new heteropolysaccharide, WPP60A, with a molecular weight of 2.4 kDa, was isolated from Wedelia prostrata by hot water extraction, and purified by DEAE Sepharose fast flow and Sephacryl S-200 high-resolution chromatography. Compositional analysis, and methylation analysis, combined with (1)H, (13)C NMR spectroscopy including 2D NMR (COSY, TOCSY, HMQC, NOESY, and HMBC) experiments demonstrated that WPP60A was composed of primarily fructose and low glucose. Results indicated that this new heteropolysaccharide consists of a repeating unit with the following structure: [Formula: see text].