Hypoglycemic effects of white hyacinth bean polysaccharide on type 2 diabetes mellitus rats involvement with entero-insular axis and GLP-1 via metabolomics study.

The present study aimed to investigate the potential effects of white hyacinth bean polysaccharide (WHBP) against type 2 diabetic mellitus (T2DM) which was established by high-glucose/high-fat for 8 weeks, combined with a low-dose streptozotocin (STZ) injection. Our results showed that WHBP behaved the hypoglycemic effect by attenuating fasting blood glucose in vivo. WHBP-mediated anti-diabetic effects associated with the attenuation of insulin resistance and pancreatic impairment, as evidenced by the mitigation of pathological changes, inflammatory response and oxidative stress in the pancreas of T2DM rats. Meanwhile, gut protection was also shown during WHBP-mediated anti-diabetic effects, and glucagon-like peptide-1 (GLP-1), a mediator of the entero-insular axis, was observed to be elevated in both gut and pancreas of WHBP groups when compared to DM group, suggesting that hypoglycemic effects of WHBP were implicated in gut-pancreas interaction. Subsequently, untargeted metabolomics analysis performed by UPLC-QTOF/MS and showed that WHBP administration significantly adjusted the levels of 40 metabolites when compared to DM group. Further data concerning pathway analysis showed that WHBP administration significantly regulated the phenylalanine metabolism, tryptophan metabolism, arginine and proline, isoleucine metabolism, and glycerophospholipid metabolism in T2DM rats. Together, our results suggested that WHBP performed hypoglycemic effects and pancreatic protection linked to entero-insular axis involvement with GLP-1 and reversed metabolic disturbances in T2DM rats.

Highland Barley ß-Glucan Relieves Symptoms of Colitis via PPARα-Mediated Intestinal Stem Cell Proliferation.

Intestinal stem cells (ISCs) are necessary to maintain intestinal renewal. Here, we found that the highland barley ß-glucan (HBG) alleviated pathological symptoms and promoted the proliferation of intestinal stem cells in colitis mice. Notably, metabolomics studies showed that docosahexaenoic acid (DHA) was significantly increased by the HBG treatment. DHA is a ligand for peroxisome proliferator-activated receptor α (PPARα), which can promote ISC proliferation. Expectedly, HBG facilitated the expression of intestinal PPARα and the proliferation of ISCs in colitis mice. Further experiments verified that DHA significantly facilitated the expression of PPARα and the proliferation of ISCs in intestinal organoids. Intriguingly, the effect of DHA on ISC proliferation was reversed by the PPARα inhibitor. Together, our data indicate that HBG might accelerate PPARα-mediated ISC proliferation through DHA. This provides new insights into the effective application of polysaccharides in maintaining intestinal homeostasis.

White hyacinth bean polysaccharide ameliorates diabetes via microbiota-gut-brain axis in type 2 diabetes mellitus rats.

Gut played a potent role in onset and progression of metabolic disorders, presenting an exciting direction for diabetes prevention. Here, the anti-diabetic effects of White hyacinth bean polysaccharides (WHBP) were observed, including the reduction of blood glucose levels and improvement of intestinal impairment in type 2 diabetes mellitus (T2DM) rats. Further data concerning intestinal protection suggested that WHBP restored intestinal barrier, as evidenced by inhibition of intestinal pathological damage, up-regulation of Zonula occluden-1 expression and manipulation of the redox system in T2DM rats. Moreover, WHBP-mediated anti-diabetic effects were in parallel with the adjustment of changes in gut microbiota composition of T2DM rats. Meanwhile, hypersecretion of corticotropin-releasing hormone, adrenocorticotropic hormone, and corticosterone levels, which were critical coordinators of the hypothalamic-pituitary-adrenal (HPA) axis, were suppressed in T2DM rats exposed to WHBP, indicating that WHBP-mediated health benefits were referring to regulate brain feedback in reduction of HPA axis. Concomitantly, further suggested and expanded on gut-brain communication by data of microbial metabolites short-chain fatty acids, mediators of gut-brain interactions, were remarkably raised in cecum contents of T2DM rats subjected to WHBP. Collectively, WHBP performed anti-diabetic effects were associated with control of microbiota-gut-brain axis implicated in intestinal barrier, HPA axis, gut microbiota and their metabolites.

Isolation and characterization of potential Lactobacillus acidophilus strains isolated from pig feces.

The aim of this study was to isolate and characterize Lactic Acid Bacteria (LAB) from 16 feces samples of pig farm, and to evaluate the probiotic potential of these isolates as potential oral probiotic candidates. The selection process was based on the isolation, identification, and a series of experiments for the selection of appropriate candidates with beneficial properties. The results demonstrated that most of LAB showed relatively strong resistance to pH 2.5 and high bile salts (1%), and had good survival in simulated gastric and intestinal juice. 9 isolates displayed antimicrobial activities against Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Enterobacter sakazakii. Almost all isolates were sensitive to ampicillin, chloramphenicol, vancomycin and amoxicillin, and most of isolates exhibited resistance against tetracycline and vancomycin. The adhesion rates of LAB varied greatly. The results of the study suggested that the Lactobacillus acidophilus NCUA065001 have the important functional property of probiotic candidates to enhance gut integrity and could considered to be the potential antibiotic alternatives in the pig feed industry.

Structural characteristic of pectin-glucuronoxylan complex from Dolichos lablab L. hull.

Polysaccharides are important constituents in Dolichos lablab hull. Herein, pectin-glucuronoxylan complex from D. lablab hull designated as DLHP-3 (D. lablab hull polysaccharide,) was prepared by ion exchange and gel permeation chromatography, and further characterized by acid degradation and enzymatic hydrolysis, methylation combined with GC-MS, NMR and MALDI-TOF-MS analysis. Both of pectin and glucuronoxylan regions were found in DLHP-3. The glucuronoxylan region consisted of a →4)-ß-Xylp-(1→ backbone with branches of α-GlcpA-(1→ substituted at O-2 site, and the ratio of xylose to glucuronic acid was about 5:1. Acetyl groups were mainly attached to O-3 site of →2,4)-ß-Xylp-(1→ residues. The main chain of pectin region could be represented by →4)-α-GalpA-(1→4)-α-GalpA-(1→ and →2)-α-Rhap-(1→4)-α-GalpA-(1→ with partial methyl-esterification. The side chains were deduced to embrace arabinan and arabinogalactan linked to rhamnogalacturonan-I region. Pectin was probably covalently bound to glucuronoxylan. Our findings uncovered the molecular structure of pectin-glucuronoxylan complex from D. lablab hull.

Gastroprotective activity of polysaccharide from the fruiting body of Hericium erinaceus against acetic acid-induced gastric ulcer in rats and structure of one bioactive fraction.

This study aimed at investigating gastroprotective activity of Hericium erinaceus polysaccharide (HEP) and characterizing one of its bioactive fractions. Acetic acid-induced gastric ulcer (GU) rat model was used to evaluate the gastroprotective activity of HEP, while H2O2-induced injury GES-1 cell model was conducted to screen the bioactive fractions from HEP. Moreover, one of the bioactive fractions was characterized using methylation and 1D/2D NMR analysis. Results indicated HEP treatment could ameliorate acetic acid-induced GU in rats. HEP supplement decreased levels of interleukin-6, tumor necrosis factor-α and malondialdehyde and myeloperoxidase activity, and increased releases of nitric oxide, prostaglandin E2, epidermal growth factor, vascular endothelial growth factor and basic fibroblast growth factor and superoxide dismutase activity in gastric tissues of ulcerated rats. Five purified polysaccharides from HEP were screened to be bioactive fractions with cytoprotection on H2O2-induced injury in GES-1 cells. Among them, RP-S was characterized to be a (1 â†’ 6)-ß-D-glucan, whose backbone was composed of →6)-ß-D-Glcp-(1 â†’ residue and branched with T-ß-D-Glcp-(1 â†’ residue at O-3 position. In conclusion, HEP possessed gastroprotection against acetic acid-induced GU in rats and one of its bioactive fractions was a ß-D-glucan. This study supports the utilization of HEP in anti-GU and provides evidences for the structure of gastroprotective HEP.

Applications of infrared spectroscopy in polysaccharide structural analysis: Progress, challenge and perspective.

Polysaccharides are important biomacromolecules with numerous beneficial functions and a wide range of industrial applications. Functions and properties of polysaccharides are closely related to their structural features. Infrared (IR) spectroscopy is a well-established technique which has been widely applied in polysaccharide structural analysis. In this paper, the principle of IR and interpretation of polysaccharide IR spectrum are briefly introduced. Classical applications of IR spectroscopy in polysaccharide structural elucidation are reviewed from qualitative and quantitative aspects. Some advanced IR techniques including integrating with mass spectrometry (MS), microscopy and computational chemistry are introduced and their applications are emphasized. These emerging techniques can considerably expand application scope of IR, thus exert a more important effect on carbohydrate characterization. Overall, this review seeks to provide a comprehensive insight to applications of IR spectroscopy in polysaccharide structural analysis and highlights the importance of advanced IR-integrating techniques.

A review of NMR analysis in polysaccharide structure and conformation: Progress, challenge and perspective.

Nuclear magnetic resonance (NMR) has been widely used as an analytical chemistry technique to investigate the molecular structure and conformation of polysaccharides. Combined with 1D spectra, chemical shifts and coupling constants in both homo- and heteronuclear 2D NMR spectra are able to infer the linkage and sequence of sugar residues. Besides, NMR has also been applied in conformation, quantitative analysis, cell wall in situ, degradation, polysaccharide mixture interaction analysis, as well as carbohydrates impurities profiling. This review summarizes the principle and development of NMR in polysaccharides analysis, and provides NMR spectra data collections of some common polysaccharides. It will help to promote the application of NMR in complex polysaccharides of biochemical interest, and provide valuable information on commercial polysaccharide products.

Isolation and structure characterization of glucuronoxylans from Dolichos lablab L. hull.

Polysaccharides were extracted by hot water and alkali in sequence from Dolichos lablab L. hull, and further purified by ion-exchange and gel columns. Hot water extracted D. lablab hull polysaccharide (DLHP) was rich in glucuronoxylan and pectin, and alkali extracted polysaccharide (DLHAP) mostly embraced glucuronoxylan. The structures of purified glucuronoxylans from DLHP and DLHAP were mainly analyzed by HPAEC-PAD, methylation combined with GC-MS, NMR and SEC-MALLS. DLHP-1 was identified as acetylated glucuronoxylan containing →4)-ß-Xylp-(1→ backbone with substitution at O-2 site by α-GlcpA/4-O-methyl-α-GlcpA. The molar ratio of ß-Xylp to α-GlcpA was 6.9:1, and acetylation was mainly at O-3 site of ß-Xylp with acetylation degree of 21.5%. DLHP-1 and DLHP-2 had similar physicochemical properties, except for molecular weight (Mw). DLHAP-1 was the non-methylated glucuronoxylan almost without acetylation, and it had the molar ratio of ß-Xylp to α-GlcpA of 5.6:1. Besides, DLHP-1 (Mw of 20.0 × 103 g mol-1) adopted semi-flexible chain, while DLHAP-1 (Mw of 15.4 × 103 g mol-1) showed flexible chain. These results provided a structural basis for study on polysaccharides from D. lablab hull, which was benefit for understanding biological activities and developing functional food or pharmaceuticals of D. lablab.

Polysaccharides from fermented Momordica charantia L. with Lactobacillus plantarum NCU116 ameliorate metabolic disorders and gut microbiota change in obese rats.

Obesity is a chronic disease characterized by overweight resulting from fat accumulation, along with disturbance of metabolism and gut microbiota. Fermentation, as a green processing method, is beneficial for improving the nutrition capacity of food components. Polysaccharides are considered as one of the important components in food and are also potential supplements for anti-obesity treatment. This study aimed to investigate the anti-obesity effects of polysaccharides from fermented and non-fermented Momordica charantia L. with Lactobacillus plantarum NCU116 (FP and NFP) on obese rats by serum metabolomics and gut microbiota analysis. Metabolomics results revealed that abnormal lipid metabolism was formed due to obesity. The supplement of FP and NFP improved the glycerophospholipids, glycosphingolipids, and amino acid metabolism of the obese rats, which alleviated the hypercholesterolemia and overweight in rats. Furthermore, the disorder of gut microbiota was ameliorated by FP and NFP. FP promoted the growth of beneficial bacteria, such as phylum Firmicutes, Actinobacteria, and genera Anaerostipes, Coprococcus, Lactobacillus, and Bifidobacterium. FP also reduced several harmful bacteria belonging to the phylum Proteobacteria and genera Helicobacter. The positive correlation of the weight loss and lowering of serum lipids with the increased beneficial bacteria further elucidated that the anti-obesity effect of FP in obese rats is associated with the regulation of gut microbiota and serum metabolites. The results of this study could provide information for developing probiotic products in the future that may have beneficial effects on the prevention or treatment of obesity.

Probiotic fermentation modifies the structures of pectic polysaccharides from carrot pulp.

Previous studies have suggested that water-soluble polysaccharides from fermented carrot pulp (WSP-p) have stronger anti-diabetic effects than those from un-fermented carrot pulp (WSP-n). This study aimed to improve understanding of these functional differences by comparing their molecular structures. Weight-average molecular weights of WSP-p fractions were lower than those of the corresponding WSP-n fractions. While both WSPs had similar functional groups, more fragmented particles were observed on the surface of large particles of WSP-n than WSP-p. Monosaccharide composition and methylation analysis confirmed that both WSP-p and WSP-n were pectic polysaccharides, containing rhamnogalacturonan-I-type polysaccharides with 1,4-linked α-d-galacturonic acid residues and homogalacturonan regions with 1,4-GalpA linkages. 1H and 13C NMR showed that they had similar linkage patterns. These findings suggested that probiotic fermentation of WSP mainly cleaved the linkages between repeating units, and resulted in less polydisperse molecular size distributions.

Interactions between Lactobacillus plantarum NCU116 and its environments based on extracellular proteins and polysaccharides prediction by comparative analysis.

Lactic acid bacteria (LAB) play a significant role in food industry and artisan fermented-food. Most of the applicable LABs were commonly obtained from natural fermented food or human gut. And Lactobacillus plantarum NCU116 was screened from a LAB-dominated traditional Chinese sauerkraut (TCS). In order to comprehend the interaction between NCU116 and its environments, comparative genomics were performed to identify genes involved in extracellular protein biosynthesis and secretion. Four secretory pathways were identified, including Sec and FPE pathways, holins and efflux ABC transporter system. Then 348 potential secretory proteins were identified, including 11 alpha-amylases responsible for degradation of macromolecules, and 8 mucus binding proteins which attribute to adherence to intestine epithelium. Besides, EPS clusters of NCU116 (EPS116) were identified and analyzed by comparing to other strains, which suggested a novel genotype of EPS clusters. These findings could be critical to extend the application of NCU116 in food and pharmaceuticals industries.

Molecular properties and gut health benefits of enzyme-hydrolyzed konjac glucomannans.

Konjac glucomannan (KGM) with a molecular weight (MW) of 823.4 kDa was partially degraded by endo-1,4-ß-mannanase. Two hydrolyzed KGM fractions (KGM-M-1: 147.2 kDa and KGM-M-2: 21.5 kDa) were characterized and applied to the animal tests in comparison with the native KGM. After oral feeding to the mice, KGM-M-1 and KGM-M-2 significantly increased the levels of short chain fatty acids (SCFAs) in the colonic contents and the native KGM increased the SCFAs in the cecum. The more significant effect of the native KGM in the cecum may be attributable to its high viscosity, slowing down the movement of intestinal microflora through the cecum, while the lower MW KGM-M-1 and KGM-M-2 could move more easily through the colon to be fermented by colonic bacteria. This new finding may be useful for future research and development of low-MW KGM polysaccharides through enzyme hydrolysis for the desired gut health benefits.

Ascorbic acid induced degradation of polysaccharide from natural products: a review.

Polysaccharide derived from natural products has a wide range of sources and mild properties, and exhibit various bioactivities. Ascorbic acid is one of the most important nutrients in fruits and vegetables, as well as their products. Ascorbic acid and polysaccharide coexist in many systems during food production and processing. Many studies have found that ascorbic acid at low concentrations degrades polysaccharide derived from natural products via hydroxyl radical. In this paper, the research progress on ascorbic acid induced polysaccharide degradation is summarized from four aspects: mechanism of action, analytical methods, influencing factors and bioactivity of degradation products. It is expected to provide a theoretical basis for further research.

Genomic analysis revealed adaptive mechanism to plant-related fermentation of Lactobacillus plantarum NCU116 and Lactobacillus spp.

Lactobacillus plantarum NCU116 is the first sequenced strain derived from traditional Chinese sauerkraut (TCS). Since NCU116 manifested outstanding probiotic effects in vitro and in vivo, it is crucial to comprehend a clear genetic background for NCU116. Functional re-annotation and comparative analysis were performed to excavate the unique and representative genes in NCU116, in order to investigate its metabolic preference and adaptive mechanism. Horizontal gene transfer (HGT) seemed to occur frequently, which endows NCU116 with a strong ability to transport carbohydrates, as a strain-specific fructose/mannose-PTS was identified, and opu and osmC coding genes were retrieved as NCU116-specific. In addition, a strain-specific type I R/M system and several prophage loci were found in NCU116, which could play vital roles in self-defense mechanism. Pathways of bacterial metabolism on plant-related substrates fermentation were then generated by reconstruction of associated pathways. Moreover, a unique potential plantaricin-producing locus with high homology to that of JDM1 was defined in the genome of NCU116, which could be very important for the preservation of fermented-food. Our results would provide critical basis for the application of NCU116 in food and pharmaceuticals industries.

Physicochemical and rheological properties of pomelo albedo pectin and its interaction with konjac glucomannan.

Pomelo albedo was extracted with water to obtain the high methoxyl pectin, labeled as PAP. The physicochemical and rheological properties of PAP were determined. The effects of PAP addition on rheological property and thermal stability of konjac glucomannan (KGM) were evaluated. Results indicated that PAP was composed of arabinose, glucose and galacturonic acid with a relative mass percentage of 7.2%: 9.5%: 83.3%, and exhibited an average molecular weight of 56.6 kDa. The degree of esterification of PAP was 65.5%, showing PAP was a kind of high methoxyl pectin. Apparent viscosity of PAP was concentration-dependently increased, while it was slightly enhanced with salt (NaCl or CaCl2) addition. Moreover, the addition of PAP declined the apparent viscosity, elastic property and thermal stability of KGM. It can be concluded that interaction was occurred between KGM and PAP. Meanwhile, the interaction mechanism between KGM and PAP has been preliminarily proposed. The present study can provide some references for the application of PAP and support the combination usage of this pectin and KGM in food and other industries.

Protective effect of Ganoderma atrum polysaccharides in acute lung injury rats and its metabolomics.

The present study aimed to evaluate effect of Ganoderma atrum polysaccharide (PSG) on acute lung injury (ALI) rats and its mechanisms. Results showed that PSG exhibited protective effects against ALI by maintaining pulmonary histology, reducing levels of pro-inflammatory cytokines and NO both in serum and lung tissue. Moreover, this study further evaluated the metabolic effects of PSG based on UPLC-Triple-TOF/MS metabolomics analysis in rats. Compared with control group, LysoPC (18:2), LPA (18:1), taurocholic acid, L-histidine, and L-tryptophan were identified as metabolic biomarkers in serum of ALI group. Furthermore, biological pathways analysis demonstrated that histidine metabolism, nitrogen metabolism, tryptophan and part glycerophospholipids metabolism were notably modified by PSG treatment in ALI rats. Additionally, improved gut microbial metabolite short-chain fatty acids were found after intake of PSG in ALI rat. Altogether, PSG could control ALI-induced aberrant inflammation and its mechanisms were linked to inhibit release of pro-inflammatory mediators and reverse metabolic pathway disturbances.

Inappropriateness of RNAlater to preserve Caenorhabditis elegans for RNA extraction.

Caenorhabditis elegans is a well-established laboratory animal model and has been widely used in biological research. However, it is still a challenge to obtain a good amount of quality RNA from a limited number of C. elegans for gene expression studies. To address this issue, the present study has compared different conditions to preserve C. elegans for RNA extraction after the failure of an initial effort to use RNAlater-preserved worms for RNA extraction. The effects of different concentrations of proteinase K, different worm life stages, and different worm numbers on RNA extraction were also investigated. The best results were achieved under the following conditions: 1) adult worms that were either freshly prepared or quickly frozen in liquid nitrogen followed by storage at -80 °C; 2) disruption of C. elegans with proteinase K (1 mg/mL) in a lysis buffer (65 °C for 10 min) prior to extraction with Trizol agent. This method can provide a stable, rapid, and effective means to extract RNA from C. elegans with variable worm numbers from 20 to 200. •RNAlater was inappropriate for preserving C. elegans for effective RNA extraction.•Proteinase K was verified for lysing a limited number of C. elegans for RNA extraction.

Fermented Momordica charantia L. juice modulates hyperglycemia, lipid profile, and gut microbiota in type 2 diabetic rats.

The effect of Lactobacillus plantarum-fermentation on the anti-diabetic functionality of Momordica charantia was examined using a high-fat-diet and low-dose streptozocin-induced type 2 diabetic rat model. Fermented Momordica charantia juice (FMCJ) administration mitigated the hyperglycemia, hyperinsulinemia, hyperlipidemia, and oxidative stress in diabetic rats more favorably than the non-fermented counterpart. Treatments with FMCJ improved ergosterols and lysomonomethyl-phosphatidylethanolamines metabolisms more effectively. Supplement of FMCJ regulated the composition of the gut microbiota, such as increased the abundance of Bacteroides caecigallinarum, Oscillibacter ruminantium, Bacteroides thetaiotaomicron, Prevotella loescheii, Prevotella oralis, and Prevotella melaninogenica, in diabetic rats compared with untreated diabetic rats. Moreover, FMCJ-treated diabetic rats exhibited higher concentrations of acetic acid, propionic acid, butyric acid, total short-chain fatty acids and lower pH values in colonic contents than that in non-fermented juice-treated rats. These results demonstrated that Lactobacillus plantarum-fermentation enhanced the anti-diabetic property of MC juice by favoring the regulation of gut microbiota and the production of SCFAs.

Polysaccharides from fermented Momordica charantia ameliorate obesity in high-fat induced obese rats.

Momordica charantia (M. charantia) has been widely used to treat obesity due to its bioactive ingredients. This research aimed to investigate the anti-obesity effect of polysaccharides (FP) from fermented M. charantia with Lactobacillus plantarum NCU116 on high-fat induced obese rats. We found that FP could effectively lower the body weight gain, Lee's index, insulin resistance and cell sizes of epididymal adipose tissues in obese rats compared with polysaccharides from non-fermented M. charantia (NFP). FP treatments decreased the total cholesterol, triacylglycerols, and low-density lipoprotein cholesterol, leptin, whereas they elevated the high-density lipoprotein cholesterol, adiponectin, significantly in the serum of obese rats. Furthermore, administrations of FP notably improved oxidative balance in obese rats. Lipidomics results indicated that 24 potential biomarkers have been identified in serum. Additionally, 21 lipids were considerably altered by FP and NFP intakes, such as fatty acyls, glycerolipids, sphingolipids, sterol lipids and glycerophospholipids. The anti-obesity properties of FP were revealed via relieving insulin resistance and fat accumulation of obese rats, which was associated with the regulation of lipid metabolism. Overall, FP exerted more favourable impacts on the anti-obesity effect than NFP, which may be attributed to fermentation.