PI3K/Akt/FoxO Pathway Mediates Antagonistic Toxicity in HepG2 Cells Coexposed to Deoxynivalenol and Enniatins.

The emerging mycotoxins enniatins (ENNs) and the traditional mycotoxin deoxynivalenol (DON) often co-contaminate various grain raw materials and foods. While the liver is their common target organ, the mechanism of their combined effect remains unclear. In this study, the combined cytotoxic effects of four ENNs (ENA, ENA1, ENB, and ENB1) with DON and their mechanisms were investigated using the HepG2 cell line. Additionally, a population exposure risk assessment of these mycotoxins was performed by using in vitro experiments and computer simulations. The results showed that only ENA at 1/4 IC50 and ENB1 at 1/8 IC50 coexposed with DON showed an additive effect, while ENB showed the strongest antagonism at IC50 (CI = 3.890). Co-incubation of ENNs regulated the signaling molecule levels which were disrupted by DON. Transcriptome analysis showed that ENB (IC50) up-regulated the PI3K/Akt/FoxO signaling pathway and inhibited the expression of apoptotic genes (Bax, P53, Caspase 3, etc.) via phosphorylation of FoxO, thereby reducing the cytotoxic effects caused by DON. Both types of mycotoxins posed serious health risks, and the cumulative risk of coexposure was particularly important for emerging mycotoxins.

Ultrasensitive Aptasensor for α-Amatoxin Detection Based on the DNA Tetrahedral Nanostructure Triggering Rolling Circle Amplification and Signal Amplification.

Poisonous mushrooms containing α-amatoxin can be lethal, making it imperative to develop a rapid and sensitive detection method for α-amatoxin. Utilizing the DNA tetrahedral structure as its foundation, the aptamer allows controlled density and orientation. Consequently, we designed aptamer tetrahedral functionalized magnetic beads that specifically target α-amanitin to release complementary DNA (C-DNA) strands. These strands were then employed as primers to initiate rolling circle amplification (RCA) with fluorescent dyes. The combination of SYBR Green I detection probes facilitated the amplification of the detection signal, enhancing the detection sensitivity of the aptasensor. The calculated detection limit was determined to be 3 ng/mL, a magnitude lower than that of other aptasensors by 2 orders of magnitude. The aptasensor integrates the advantages of high sensitivity and specificity, offering a simple and reliable rapid detection method for α-amanitin analysis.

Antimicrobial carbon dots/pectin-based hydrogel for promoting healing processes in multidrug-resistant bacteria-infected wounds.

Multidrug-resistant (MDR) bacterial infections have become a significant threat to global healthcare systems. Here, we developed a highly efficient antimicrobial hydrogel using environmentally friendly garlic carbon dots, pectin, and acrylic acid. The hydrogel had a porous three-dimensional network structure, which endowed it with good mechanical properties and compression recovery performance. The hydrogel could adhere closely to skin tissues and had an equilibrium swelling ratio of 6.21, indicating its potential as a wound dressing. In particular, the bactericidal efficacy following 24-h contact against two MDR bacteria could exceed 99.99 %. When the hydrogel was applied to epidermal wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) on mice, a remarkable healing rate of 93.29 % was observed after 10 days. This was better than the effectiveness of the traditionally used antibiotic kanamycin, which resulted in a healing rate of 70.36 %. In vitro cytotoxicity testing and hemolysis assay demonstrated a high biocompatibility. This was further proved by the in vivo assay where no toxic side effects were observed on the heart, liver, spleen, lung, or kidney of mice. This eco-friendly and easy-to-prepare food-inspired hydrogel provides an idea for the rational use of food and food by-products as a wound dressing to control MDR bacterial infections.

Ultrasensitive Detection Strategy of Norovirus Based on a Dual Enhancement Strategy: CRISPR-Responsive Self-Assembled SNA and Isothermal Amplification.

Spherical nucleic acids (SNAs) have been used to construct various nanobiosensors with gold nanoparticles (AuNPs) as nuclei. The SNAs play a critical role in biosensing due to their various physical and chemical properties, programmability, and specificity recognition ability. In this study, CRISPR-responsive self-assembled spherical nucleic acid (CRISPR-rsSNA) detection probes were constructed by conjugating fluorescein-labeled probes to the surface of AuNPs to improve the sensing performance. Also, the mechanism of ssDNA and the role of different fluorescent groups in the self-assembly process of CRISPR-rsSNA were explored. Then, CRISPR-rsSNA and reverse transcription-recombinase polymerase amplification (RT-RPA) were combined to develop an ultrasensitive fluorescence-detection strategy for norovirus. In the presence of the virus, the target RNA sequence of the virus was transformed and amplified by RT-RPA. The resulting dsDNA activated the trans-cleavage activity of CRISPR cas12a, resulting in disintegrating the outer nucleic acid structure of the CRISPR-rsSNA at a diffusible rate, which released reporter molecules. Norovirus was quantitated by fluorescence detection. This strategy facilitated the detection of the norovirus at the attomolar level. An RT-RPA kit for norovirus detected would be developed based on this method. The proposed method would be used for the detection of different viruses just by changing the target RNA and crRNA of the CRISPR cas12a system which provided a foundation for high-throughput detection of various substances.

Investigating enzyme kinetics and fluorescence sensing strategy of CRISPR/Cas12a for foodborne pathogenic bacteria.

Foodborne pathogenic bacteria are widespread in various foods, whose cross-contamination and re-contamination are critical influences on food safety. Rapid, accurate, and sensitive detection of foodborne pathogenic bacteria remains a topic of concern. CRISPR/Cas12a can recognize double-stranded DNA directly, showing great potential in nucleic acid detection. However, few studies have investigated the cleavage properties of CRISPR/Cas12a. In this study, the trans-cleavage properties of LbCas12a and AsCas12a were investigated to construct the detection methods for foodborne pathogenic bacteria. The highly sensitive fluorescent strategies for foodborne pathogens were constructed by analyzing the cleavage rates and properties of substrates at different substrate concentrations. Cas12a was activated in the presence of foodborne pathogenic target sequence was present, resulting in the cleavage of a single-stranded reporter ssDNA co-labelled by fluorescein quencher and fluorescein. The sensitivity and specificity of the Cas12a fluorescent strategy was investigated with Salmonella and Staphylococcus aureus as examples. The results showed that AsCas12a was slightly more capable of trans-cleavage than LbCas12a. The detection limits of AsCas12a for Salmonella and Staphylococcus aureus were 24.9 CFU mL-1 and 1.50 CFU mL-1, respectively. In all the seven bacteria, Staphylococcus aureus and Salmonella were accurately discriminated. The study provided a basis for constructing and improving the CRISPR/Cas12a fluorescence strategies. The AsCas12a-based detection strategy is expected to be a promising method for field detection.

Double phage displayed peptides co-targeting-based biosensor with signal enhancement activity for colorimetric detection of Staphylococcus aureus.

The development of simple, fast, sensitive, and specific strategies for the detection of foodborne pathogenic bacteria is crucial for ensuring food safety and promoting human health. Currently, detection methods for Staphylococcus aureus still suffer from issues such as low specificity and low sensitivity. To address this problem, we proposed a sensitivity enhancement strategy based on double phage-displayed peptides (PDPs) co-targeting. Firstly, we screened two PDPs and analyzed their binding mechanisms through fluorescent localization, pull-down assay, and molecular docking. The two PDPs target S. aureus by binding to specific proteins on its outer membrane. Based on this phenomenon, a convenient and sensitive double PDPs colorimetric biosensor was developed. Double thiol-modified phage-displayed peptides (PDP-SH) enhance the aggregation of gold nanoparticles (AuNPs), whereas the specific interaction between the double PDPs and bacteria inhibits the aggregation of AuNPs, resulting in an increased visible color change before and after the addition of bacteria. This one-step colorimetric approach displayed a high sensitivity of 2.35 CFU/mL and a wide detection range from 10-2 × 108 CFU/mL. The combination with smartphone-based image analysis improved the portability of this method. This strategy achieves the straightforward, highly sensitive and portable detection of pathogenic bacteria.

Recent advances in biosynthesis of mycotoxin-degrading enzymes and their applications in food and feed.

Mycotoxins are secondary metabolites produced by fungi in food and feed, which can cause serious health problems. Bioenzymatic degradation is gaining increasing popularity due to its high specificity, gentle degradation conditions, and environmental friendliness. We reviewed recently reported biosynthetic mycotoxin-degrading enzymes, traditional and novel expression systems, enzyme optimization strategies, food and feed applications, safety evaluation of both degrading enzymes and degradation products, and commercialization potentials. Special emphasis is given to the novel expression systems, advanced optimization strategies, and safety considerations for industrial use. Over ten types of recombinases such as oxidoreductase and hydrolase have been studied in the enzymatic hydrolysis of mycotoxins. Besides traditional expression system of Escherichia coli and yeasts, these enzymes can also be expressed in novel systems such as Bacillus subtilis and lactic acid bacteria. To meet the requirements of industrial applications in terms of degradation efficacy and stability, genetic engineering and computational tools are used to optimize enzymatic expression. Currently, registration and technical difficulties have restricted commercial application of mycotoxin-degrading enzymes. To overcome these obstacles, systematic safety evaluation of both biosynthetic enzymes and their degradation products, in-depth understanding of degradation mechanisms and a comprehensive evaluation of their impact on food and feed quality are urgently needed.

Effects of FB1 and HFB1 on Autonomous Exploratory and Spatial Memory and Learning Abilities in Mice.

Fumonisin B1 (FB1) is a representative form of fumonisin and is widely present in food and feed. Hydrolyzed fumonisin B1 (HFB1) emerges as a breakdown product of FB1, which is accompanied by FB1 alterations. While previous studies have primarily focused on the liver or kidney toxicity of FB1, with limited studies existing on its neurotoxicity and even fewer on the toxicity of HFB1, this study focuses on the neurotoxicity of FB1 and HFB1 exposure in mice investigated by the open field test, Morris water maze test, histopathological analysis, and nontargeted metabolomics. Further, the levels of oxidative stress-related indices, neurotransmitters, and sphingolipids in the brain were measured to analyze their correlation with behavioral outcomes. The results showed that both FB1 (5 mg/kg) and HFB1 (2.8 mg/kg) reduced autonomous exploratory behavior in mice, impaired spatial learning and memory, and caused mild abnormalities in the brain structure. Quantitative analysis further indicated that exposure to FB1 and HFB1 disrupted neurotransmitter homeostasis, exacerbated oxidative stress, and significantly increased the sphinganine/sphingosine (Sa/So) ratio. Moreover, HFB1 exhibited neurotoxic effects similar to those of FB1, emphasizing the need to pay attention to the neurotoxicity effect of HFB1. These findings underscore the importance of understanding the risks and potential neurological damage associated with FB1 and HFB1 exposure, highlighting the necessity for further research in this crucial field.

Exploring the impact of fungal spores from agricultural environments on the mice lung microbiome and metabolic profile.

Exposure to particulate matter (PM) from agricultural environments has been extensively reported to cause respiratory health concerns in both animals and agricultural workers. Furthermore, PM from agricultural environments, containing fungal spores, has emerged as a significant threat to public health and the environment. Despite its potential toxicity, the impact of fungal spores present in PM from agricultural environments on the lung microbiome and metabolic profile is not well understood. To address this gap in knowledge, we developed a mice model of immunodeficiency using cyclophosphamide and subsequently exposed the mice to fungal spores via the trachea. By utilizing metabolomics techniques and 16 S rRNA sequencing, we conducted a comprehensive investigation into the alterations in the lung microbiome and metabolic profile of mice exposed to fungal spores. Our study uncovered significant modifications in both the lung microbiome and metabolic profile post-exposure to fungal spores. Additionally, fungal spore exposure elicited noticeable changes in α and ß diversity, with these microorganisms being closely associated with inflammatory factors. Employing non-targeted metabolomics analysis via GC-TOF-MS, a total of 215 metabolites were identified, among which 42 exhibited significant differences. These metabolites are linked to various metabolic pathways, with amino sugar and nucleotide sugar metabolism, as well as galactose metabolism, standing out as the most notable pathways. Cysteine and methionine metabolism, along with glycine, serine and threonine metabolism, emerged as particularly crucial pathways. Moreover, these metabolites demonstrated a strong correlation with inflammatory factors and exhibited significant associations with microbial production. Overall, our findings suggest that disruptions to the microbiome and metabolome may hold substantial relevance in the mechanism underlying fungal spore-induced lung damage in mice.

Sleep Promotion by 3-Hydroxy-4-Iminobutyric Acid in Walnut Diaphragma juglandis Fructus.

Insufficient sleep can produce a multitude of deleterious repercussions on various domains of human well-being. Concomitantly, the walnut (Juglans mandshurica) confers numerous salutary biological activities pertaining to sleep. Nevertheless, the sedative and hypnotic capacities of walnut's functional constituents remain obscure. In this investigation, we analyzed the sedative and hypnotic components of the walnut Diaphragma juglandis fructus and innovatively discovered a compound, defined as 3-hydroxy-4-iminobutyric acid (HIBA), which disrupts motor activity and enhances sleep duration by regulating the neurotransmitters (GABA, DA, etc.) within the brain and serum of mice. Subsequently, a metabolomics approach of the serum, basal ganglia, hypothalamus, and hippocampus as well as the gut microbiota was undertaken to unravel the underlying molecular mechanisms of sleep promotion. Our data reveal that HIBA can regulate the metabolism of basal ganglia (sphingolipids, acylcarnitines, etc.), possibly in relation to HIBA's influence on the gut microbiome (Muribaculum, Bacteroides, Lactobacillus, etc.). Therefore, we introduce a novel natural product, HIBA, and explicate the modulation of sleep promotion in mice based on the microbiota-gut-brain axis. This study contributes fresh insights toward natural product-based sleep research.

Metabolic reprogramming of the glutathione biosynthesis modulates the resistance of Salmonella Derby to ceftriaxone.

Salmonella, a foodborne pathogen, has become a major public health concern because of its widespread drug resistance, including resistance to multiple drugs such as third-generation cephalosporin, ceftriaxone (CRO). However, the metabolic profile changes and associated mechanisms engendered by cephalosporin-resistant mutations remain uncharted. In this study, we have employed the LC-MS/MS metabolomics platform to determine the metabolic profiles of 138 strains of Salmonella. Our results show that metabolic profiles correspond to specific serotypes, sources, processing stages, and antibiotic resistance patterns. Notably, we observed that Salmonella Derby (S. Derby) with drug resistance to CRO has a different metabolic status with changes in glutathione biosynthesis. Specifically, glutathione oxidized (GSSG) and citrulline abundances are greatly suppressed in CRO-resistant S. Derby. Furthermore, exogenous GSSG or citrulline, but not glutathione reduced (GSH), restored the susceptibility of multidrug-resistant S. Derby to CRO. This study establishes a strategy based on functional metabolomics to manage the survival of antibiotic-resistant bacteria.

Combined metabolomics and transcriptomics analysis reveals the mechanism of antibiotic resistance of Salmonella enterica serovar Typhimurium after acidic stress.

Drug-resistant Salmonella is widely distributed in the meat production chain, endangering food safety and public health. Acidification of meat products during processing can induce acid stress, which may alter antibiotic resistance. Our study investigated the effects of acid stress on the antibiotic resistance and metabolic profile of Salmonella Typhimurium, and explored the underlying mechanisms using metabolomic and transcriptomic analysis. We found that acid-stressed 14028s was more sensitive to small molecule hydrophobic antibiotics (SMHA) while more resistant to meropenem (MERO). Metabolomic analysis revealed that enhanced sensitivity to SMHA was correlated with increased purine metabolism and tricarboxylic acid cycle. Transcriptomic analysis revealed the downregulation of chemotaxis-related genes, which are also associated with SMHA sensitivity. We also found a significant downregulation of the ompF gene, which encodes a major outer membrane protein OmpF of Salmonella. The decreased expression of OmpF porin hindered the influx of MERO, leading to enhanced resistance of the bacteria to the drug. Our findings contribute to greatly improve the understanding of the relationship between Salmonella metabolism, gene expression, and changes in drug resistance after acid stress, while providing a structural framework for exploring the relationship between bacterial stress responses and antibiotic resistance.

Long-term chronic food-derived arsenic exposure induce the urinary system metabolic dysfunction in mice.

The consumption of rice contaminated with arsenic on a long-term basis has emerged as a pressing public health issue of global significance. Arsenic-induced urinary injury, particularly kidney damage, has received widespread attention. In this study, mice model under long-term arsenic exposure was established, mouse were exposed to rice arsenic (30 mg/kg) for 14 months. Changes of related metabolites were observed based on kidney metabolomics and lipidomics, and major biomarkers were screened by urine metabolomics. The results showed that phosphatidylethanolamine (PE) was significantly increased and phosphatidycholine (PC) and phosphatidylglycerol (PG) were significantly reduced after arsenic exposure, leading to related downstream lipid metabolism disorders. The metabolic pathways for amino acid and energy were observed to be impacted. In addition, metabolic disorders due to arsenic exposure may be associated with inherited neurometabolic disorders, such as D-2-hydroxyglutaric aciduria (D-2-HGA), and pyruvate carboxylase deficiency (PCD), which is predicted based on significant difference biomarkers (2-oxoglutarate, malic acid, and succinic acid) screened for urine. This study elucidates the mechanism of toxicity in the urinary system induced by arsenic exposure at nearly half life cycle, which furnishes crucial scientific evidence pertaining to the toxicity and risk evaluation associated with chronic exposure to the arsenic.

Effect of Baking Conditions and Glucose Addition on the Changes and Transformations between Fumonisins and their Covert Forms during Corn Crisp Processing.

This study investigated the impact of baking factors on fumonisin B (FB) levels in corn crisps using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results indicated that both free and total FBs decreased with an increase in baking time and temperature, while glucose addition facilitated this reduction. Total FBs reached the lowest value of 109.69 ng/g after 50 min of baking. Conversely, covert FBs increased with baking time but decreased with glucose addition at high temperatures. Additionally, the highest levels of hydrolyzed FBs (HFBs), N-(carboxymethyl) FB1, and N-(deoxy-d-fructos-1-yl) FB1 occurred 20 min before decomposing and were detected in corn crisps baked at 160 °C. Glucose addition accelerated the transformation between free and covert FBs. Furthermore, the inhibition of NCM FB1 accumulation was accompanied by the promotion of NDF FB1 accumulation during corn crisp processing. These findings provide insights into the effect of baking factors on FBs and suggest strategies for reducing FB contamination in corn crisps.

A Simplified Amplification-Free Strategy with Lyophilized CRISPR-CcrRNA System for Drug-Resistant Salmonella Detection.

Drug resistance in pathogenic bacteria has become a major threat to global health. The misuse of antibiotics has increased the number of resistant bacteria in the absence of rapid, accurate, and cost-effective diagnostic tools. Here, an amplification-free CRISPR-Cas12a time-resolved fluorescence immunochromatographic assay (AFC-TRFIA) is used to detect drug-resistant Salmonella. Multi-locus targeting in combination crRNA (CcrRNA) is 27-fold more sensitive than a standalone crRNA system. The lyophilized CRISPR system further simplifies the operation and enables one-pot detection. Induction of nucleic acid fixation via differentially charged interactions reduced the time and cost required for flowmetric chromatography with enhanced stability. The induction of nucleic acid fixation via differentially charged interactions reduces the time and cost required for flowmetric chromatography with enhanced stability. The platform developed for the detection of drug-resistant Salmonella has an ultra-sensitive detection limit of 84 CFU mL-1 within 30 min, with good linearity in the range of 102 -106 CFU mL-1 . In real-world applications, spiked recoveries range from 76.22% to 145.91%, with a coefficient of variation less than 10.59%. AFC-TRFIA offers a cost-effective, sensitive, and virtually equipment-independent platform for preventing foodborne illnesses, screening for drug-resistant Salmonella, and guiding clinical use.

Rapid generation of high-quality recombinant antibodies using an Expi293F expression system for a 17 ß-estradiol immunoassay.

The rapid generation of high-quality target antibodies is essential for research employing immunoassays. The use of recombinant antibody technology that relies on genetic engineering is one such means to produce high-quality antibodies. Obtaining the gene sequence information of immunoglobulin is a prerequisite for the preparation of genetically engineered antibodies. At present, many researchers have shared their amino acid sequence data for various high-performance antibodies and their related properties. In this study, we obtained the protein sequence of a variable region of a 17 ß-estradiol (E2) antibody from the Protein Data Bank (PDB) and subsequently constructed heavy (H) and light (L) chain expression vectors through codon optimization. The transient expression, purification, and performance identification of the immunoglobulin G (IgG), antigen-binding fragment (Fab), and single-chain variable fragment (scFv) antibodies were carried out, respectively. The effects of the different expression vectors on the expression yield of the IgG antibody were further compared. Among them, the expression yield based on the pTT5 vector was the highest, reaching 27 mg/L. Based on the expressed IgG and Fab antibodies, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) standard curve of E2 was constructed, and the half-maximal inhibitory concentrations (IC50) for these two antibodies were determined to be 0.129 ng/mL and 0.188 ng/mL, respectively. In addition, an immunochromatographic assay (ICA) based on the IgG antibody was constructed with an IC50 of 3.7 ng/mL. Therefore, in featuring the advantages of simplicity, high efficiency, rapid obtainment, and high titer yield, we propose the system for the rapid generation of high-quality recombinant antibodies by reusing the published antibody information and show that it has good implementation prospects in improving upon existing immunoassay techniques.

A highly sensitive fluorescence immunochromatography strip for thiacloprid in fruits and vegetables using recombinant antibodies.

Thiacloprid (TCL) is a neonicotinoid insecticide. Its widespread use has led to high levels of residue in fruits and vegetables. Hence, it is important to detect TCL rapidly, accurately, and sensitively in fruits and vegetables. Recombinant antibodies (rAbs) can be synthesized rapidly with little batch-to-batch variation. In this study, recombinant single-chain variable fragment (scFv) antibody and full-length recombinant antibody against TCL were produced using three different expression systems (E. coli, yeast, and mammalian cell). The results of SDS-PAGE and non - competitive enzyme-linked immunosorbent assay (ELISA) indicated that the full-length rAb exhibited promising characteristics, and the IC50 value of indirect competitive ELISA (ic-ELISA) was 2.63 µg L-1. However, recombinant scFv antibody had little affinity for the antigen. To understand antibody recognition, the three-dimensional (3D) model of the variable fragment (Fv) was built via homologous modeling. The interaction between Fv and TCL was analyzed via molecular docking and the results of molecular docking showed that VAL-158, ALA-211, PHE-220, TRP-218, TRP-49, and ILE-100 were mainly responsible for antibody recognition. In addition, a time-resolved fluorescent microsphere-immunochromatographic test strip (TRFM-ICTS) was developed with a linear range and limit of detection of 0.01-10 ng mL-1 and 0.003 ng mL-1 within 15 min under optimal conditions. The IC50 value was 4.268 ng mL-1, and the recovery ranged between 79.4% and 118.6%, which was consistent with HPLC-MS. The TRFM-ICTS has great advantages in sensitivity and applicability.

Metabolic pathway-based self-assembled Au@MXene liver microsome electrochemical biosensor for rapid screening of aflatoxin B1.

Cytochrome P450 enzymes (CYPs) catalyze the production of aflatoxin B1 (AFB1) metabolites, which play an important role in carcinogenesis. In this study, we report a simple electrochemical liver-microsome-based biosensor using a composite of gold nanoparticles adsorbed on MXene (Au@MXene) for rapid screening of AFB1. Rat liver microsomes (RLMs) were directly adsorbed on the Au@MXene nanocomposite. The high conductivity, large specific surface area, and good biocompatibility of the Au@MXene nanocomposite enabled the direct electron transfer between the RLMs and the electrode and maintained the biological activity of the enzyme in the RLMs to a large extent. The metabolic behavior of the RLM biosensor that was developed for the electrocatalyst of AFB1 to its hydroxylation metabolite aflatoxin M1 (AFM1) was confirmed. Based on the change in the electrical signal generated by this metabolic behavior, we established the relationship between AFB1 content and amperometric (I-t) current signal. When the AFB1 concentration ranged from 0.01 µM to 50 µM, the AFB1 concentration was linearly related to the electrical signal with a limit of detection of 2.8 nM. The results of the recovery experiments for corn samples showed that the recovery and accuracy of the sensor were consistent with the UPLC-MS/MS method.

Structural characterization and anti-inflammatory activity of a novel neutral polysaccharide isolated from Smilax glabra Roxb.

Crude polysaccharides isolated from Smilax glabra were screened for anti-inflammatory activity using mice ear swelling animal experiments, during which the neutral polysaccharide S1 was identified. The structural characteristics and anti-inflammatory effects of the anti-inflammatory S1 polysaccharide were then investigated. The results showed that S1 was mainly composed of rhamnose, arabinose, galactose, glucose, xylose, and mannose. The structure of the main chain consisted of →6)-α-Galp-(1 â†’ 6)-ß-Galp-(1 â†’ 4)-α-Xylp-(1 â†’ 6)-ß-Galp-(1→, with branched chains comprising α-Araf-(1 â†’ 4)-α â†’ Manp-(1 â†’ and ß-Rhap-(1 â†’ 4)-α-Glcp-(1 â†’ units. Furthermore, S1 did not have a triple helix conformation. S1 could inhibit NO secretion, reduce the levels of pro-inflammatory factors (IL-6 and TNF-α), and significantly reduce LPS-stimulated inflammatory damage in RAW 264.7 cells by inhibiting activation of the NF-κB (p65) pathway. These results shed light on the possibility of S1 to be developed as a novel anti-inflammatory drug for therapeutic purposes.

Positive effects of steamed Polygonatum sibiricum polysaccharides including a glucofructan on fatty acids and intestinal microflora.

Steam-processed Polygonatum sibiricum (PS) has been used as food for thousands of years. However, fewer studies concentrated on the effects of polysaccharides (SPSP) from the steamed PS on the intestinal tract. With fermentation in vitro, we investigated the impact of SPSP on the fatty acids and microbiotas. Results showed significant increases in short-chain fatty acids (SCFAs) like acetic acid and propionic acid, and long-chain fatty acids (LCFAs) like cis, cis, cis-9,12,15-linolenic acid, cis-6-octadecenoic acid, and cis-9-octadecenoic acid after 12 h. The positive-associated beneficial microbiotas were observed with proliferation like Parabacteroides and Bifidobacterium. Harmful microbiota like Shigella showed decreased abundance. Further, a small molecule polysaccharide was separated from the SPSP with the structure of one glucose and ten fructose, which significantly increased SCFAs and LCFAs contents during fermentation. The potential benefits of SPSP were proved by the analysis of fatty acid levels and the intestinal microbiotas during fermentation.