Preparation, stability, and antibacterial activity of carboxymethylated Anemarrhena asphodeloides polysaccharide-chitosan nanoparticles loaded curcumin.

In present study, polysaccharide polyelectrolyte nanoparticles (CMAAP-CS NPs) were constructed by mixing carboxymethylated Anemarrhena asphodeloides polysaccharide (CMAAP) and chitosan (CS). CMAAP-CS NPs were applied as carrier to improve the bioavailability and stability of curcumin (Cur). The average particle size of CMAAP-CS NPs was 216.60 ± 4.21 nm and the entrapment efficiency of Cur reached 82.50 ± 2.09 %. The simulated digestion experiments in vitro confirmed that the bioavailability of Cur loaded in CMAAP-CS NPs was 59.84 ± 0.03 % after saliva, gastric and intestinal digestion, which was obvious higher than 21.57 ± 0.07 % of free Cur under the same conditions. The results of stability testing revealed that CMAAP-CS NPs could markedly reduce the degradation of Cur against storage, heating, UV light treatment, and neutral pH. This study provided promising polyelectrolyte complex loaded hydrophobic nutrients in medicine industry.

PTIP Deficiency in B Lymphocytes Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice.

BACKGROUND: Immune dysregulation contributes to the development of ulcerative colitis (UC). The research on the inflammatory response of UC is mainly focused on T cells, with less understanding of the role of B cells. Pax transactivation domain-interacting protein (PTIP) is essential for the development of B cell subpopulations and humoral immunity. The purpose of this study was to elucidate the role of PTIP in B cells of mice with dextran sodium sulfate (DSS)-induced colitis. METHODS: The B-cell-specific PTIP knockout (PTIP-/-) mice were established by crossbreeding cluster of differentiation (CD)19cre/cre mice with PTIPflox/flox mice. The UC mice were induced by drinking water supplemented with 3.8% Dextran Sulfate Sodium (DSS) (PTIP-/- + DSS). The histological analysis was performed using hematoxylin and eosin staining. The immune cells were isolated using a fluorescence-activated cell sorter. The serum antibodies (immunoglobulin M (IgM) or immunoglobulin G (IgG)) and tumor necrosis factor (TNF)-α were determined by Enzyme linked immunosorbent assay (ELISA). RESULTS: Interestingly, our findings demonstrate that PTIP deficiency in B cells significantly ameliorates UC. In contrast to PTIP-/- + DSS, the wild type (WT) + DSS group showed a more robust increase in disease activity index (DAI) scores (p < 0.05), a substantially shortened colon (p < 0.001) and a decrease of mucous-producing goblet cells and the complete destruction of crypts. Moreover, PTIP-deficient mice manifested markedly altered neutrophil and T-cell distribution in UC (p < 0.05). Although anti-commensal IgG exacerbates UC, we demonstrated, for the first time, that serum natural IgG does not aggravate the pathology of UC. Furthermore, PTIP regulates UC by controlling B-2 cells independently from T cells. CONCLUSIONS: Transplantation of splenic B-2 cells from PTIP-deficient mice protected recipient NOD/ShiltJGpt-Prkdcem26Cd52Il2rgem26Cd22/Gpt (NCG) mice from severe UC.

Carboxymethylation modification, characterization of dandelion root polysaccharide and its effects on gel properties and microstructure of whey protein isolate.

In the present study, a native polysaccharide (DP) with sugar content of 87.54 ± 2.01 % was isolated from dandelion roots. DP was chemically modified to obtain a carboxymethylated polysaccharide (CMDP) with DS of 0.42 ± 0.07. DP and CMDP were composed of the same six monosaccharides including mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose. The molecular weights of DP and CMDP were 108,200 and 69,800 Da, respectively. CMDP exhibited more stable thermal performance and better gelling properties than DP. The effects of DP and CMDP on the strength, water holding capacity (WHC), microstructure, and rheological properties of whey protein isolate (WPI) gels were investigated. Results showed that CMDP-WPI gels had higher strength and WHC than DP-WPI gels. With the addition of 1.5 % CMDP, WPI gel had a good three-dimensional network structure. The apparent viscosities, loss modulus (G"), and storage modulus (G') of WPI gels were increased with the polysaccharide addition, the influence of CMDP was remarkable compared to DP at the same concentration. These findings suggest that CMDP may be used as a functional ingredient in protein-containing food products.

[Effect of Uremic Clearance Granules on improvement of chronic kidney disease in rats based on microbiome-metabolomics and its mechanism].

This research aimed to study the effect of Uremic Clearance Granules on chronic kidney disease in SD rats by using the methods of microbial functional genomics combined with metabolomics, and to preliminarily explore its mechanism. The SD rat model of chronic kidney disease was established by the adenine-induced method. After the model was successfully induced, the animals were randomly divided into a negative control group, a Uremic Clearance Granule treatment group, and a normal control group, with 8 rats in each group. After 4 weeks of administration, animal feces and serum were collected, and 16S rDNA sequencing technology was used to analyze the abundance, diversity, and function prediction of intestinal microorganisms. Liquid chromatography-mass spectrometry(LC-MS) technology was used to perform high-throughput sequencing to detect animal serum metabolites. The MetPA database was used to screen out potential biomarkers of chronic kidney disease in rats and conduct the enrichment analysis of metabolic pathways. Spearman's method was used to analyze the correlation between the two omics. The results showed that Uremic Clearance Granules effectively improved the body weight loss and renal function-related biochemical and appearance indicators in rats with chronic kidney disease. The results of 16S rDNA sequencing showed that Uremic Clearance Granules regulated the diversity and composition of the intestinal flora in rats with chronic kidney disease. The changes in the intestinal flora affected functional metabolic pathways such as amino acid biosynthesis and metabolism, lipid metabolism, and carbohydrate metabolism. The results of LC-MS showed that as compared with the negative control group, 15 metabolites were reversed in the Uremic Clearance Granule treatment group, among which 11 potential marker metabolites were significantly up-regulated and 4 potential marker metabolites were significantly down-regulated. Five amino acid metabolic pathways were mainly involved, which were significantly correlated with changes in the intestinal flora. Therefore, Uremic Clearance Granules can improve the renal function of rats with chronic kidney disease, and the mechanism may be related to its effect on the amino acid metabolism pathway by regulating the intestinal flora.

Optimization of ultrasound-assisted aqueous two-phase extraction of polysaccharides from seabuckthorn fruits using response methodology, physicochemical characterization and bioactivities.

BACKGROUND: Seabuckthorn fruits contains many active subtances, among them, the seabuckthorn polysaccharide is one of the main active ingredients, and exhibits diverse bioactivities. The extraction of polysaccharides from seabuckthorn fruits is the most important step for their wide applications. Ultrasound-assisted aqueous two-phase extraction (UA-ATPE) is a promising green method for extracting polysaccharides. Additionally, physicochemical characterization and antioxidant activities can evaluate the potential functions and applications in the food and medicine industries. RESULTS: Based on the single-factor experiments, 20.70% (w/w) ammonium sulfate ((NH4 )2 SO4 ) and 27.56% (w/w) ethanol were determined as the suitable composition for aqueous two-phase. The optimum conditions of UA-ATPE obtained by response surface methodology were as follows: ultrasonic power (390 W), extraction time (41 min), liquid-to-material ratio (72: 1 mL/g), and the total yield of the polysaccharides reached 34.14 ± 0.10%, The molecular weights of the purified upper-phase seabuckthorn polysaccharide (PUSP) and the purified lower-phase seabuckthorn polysaccharide (PLSP) were 65 525 and 26 776 Da, respectively. PUSP and PLSP contained the same six monosaccharides (galacturonic acid, rhamnose, xylose, mannose, glucose and galactose), but with different molar ratios. Furthermore, PUSP and PLSP displayed certain viscoelastic property, had no triple helical structure, possessed different thermal stability, surface morphology and conformation in aqueous solution. PUSP and PLSP displayed strong antioxidant properties by the assays of scavenging ability of ABTS+ ·, the protection of DNA damage and erythrocyte hemolysis. CONCLUSION: UA-ATPE significantly increased the yield of seabuckthorn polysaccharides. PUSP and PLSP were different in many aspects, such as molar ratio, surface shape and antioxidant activities. Seabuckthornpolysaccharides possess great potential in medicine and functional foods. © 2022 Society of Chemical Industry.

Preparation, characterization and bioactivities of selenized polysaccharides from Lonicera caerulea L. fruits.

Native polysaccharide was obtained from Lonicera caerulea L. fruits (PLP). Two selenized polysaccharides (PSLP-1 and PSLP-2) were synthesized by the microwave-assisted HNO3-Na2SeO3 method, where the selenium (Se) contents were 228 ± 24 and 353 ± 36 µg/g, respectively. The molecular weights of PLP, PSLP-1, and PSLP-2 were 5.9 × 104, 5.6 × 104, and 5.1 × 104 kDa, respectively. PSLP-1 and PSLP-2 contained the same type of monosaccharides as PLP but with different molar ratios. The main chain structure of the native polysaccharide was not changed after selenization. PLP, PSLP-1, and PSLP-2 contained the same six types of glycosidic bonds. Bioactivity assays revealed that the two selenized polysaccharides possessed better antioxidant activities than PLP, but their bile acid-binding abilities and inhibitory activities on acetylcholinesterase (AChE) had weakened. In summary, PLP, PSLP-1, and PSLP-2 may be promising Se supplements in functional foods and inhibitors for the treatment of AChE.

Disrupted topological organization of the motor execution network in Wilson's disease.

Objective: There are a number of symptoms associated with Wilson's disease (WD), including motor function damage. The neuropathological mechanisms underlying motor impairments in WD are, however, little understood. In this study, we explored changes in the motor execution network topology in WD. Methods: We conducted resting-state functional magnetic resonance imaging (fMRI) on 38 right-handed individuals, including 23 WD patients and 15 healthy controls of the same age. Based on graph theory, a motor execution network was constructed and analyzed. In this study, global, nodal, and edge topological properties of motor execution networks were compared. Results: The global topological organization of the motor execution network in the two groups did not differ significantly across groups. In the cerebellum, WD patients had a higher nodal degree. At the edge level, a cerebello-thalamo-striato-cortical circuit with altered functional connectivity strength in WD patients was observed. Specifically, the strength of the functional connections between the cerebellum and thalamus increased, whereas the cortical-thalamic, cortical-striatum and cortical-cerebellar connections exhibited a decrease in the strength of the functional connection. Conclusion: There is a disruption of the topology of the motor execution network in WD patients, which may be the potential basis for WD motor dysfunction and may provide important insights into neurobiological research related to WD motor dysfunction.

Association between hypertriglyceridemic-waist phenotype and non-alcoholic fatty liver disease: a general population-based study.

BACKGROUND: Hypertriglyceridemic-waist (HTGW) phenotype has been proposed as a practical tool for screening the risk of cardiovascular diseases and glycemic metabolic disease. This study sought to investigate the relationship between HTGW phenotype and non-alcoholic fatty liver disease (NAFLD). METHODS: A total of 14,251 subjects who took part in health screening were enrolled in the study and NAFLD was diagnosed by abdominal ultrasound. According to triglyceride (TG) and waist circumference, the study population was divided into four phenotypes, in which HTGW phenotype was defined as TG ≥ 1.7 mmol/L and male waist circumference ≥ 90 cm or female waist circumference ≥ 80 cm. Multivariate logistic regression analysis was used to evaluate the relationship between HTGW phenotype and NAFLD. RESULTS: In the current study, 2.43% of the subjects had HTGW phenotype, while the prevalence of NAFLD in subjects with HTGW phenotype was 77.81%. After full adjustment for covariates, compared with people with normal waist circumference and TG levels, the risk of NAFLD in people with normal TG levels but enlarged waist circumference increased by 39% [OR:1.39, 95%CI: 1.15, 1.68], in people with normal waist circumference but elevated TG levels increased by 96% [OR:1.96, 95%CI: 1.65, 2.33], and in subjects with HTGW phenotype increased by 160% [OR:2.60, 95%CI: 1.88, 3.58]. Additionally, further analysis suggested that there were significant interactions between age, height, BMI and NAFLD risk associated with TGW phenotypes. Receiver operating characteristic curves analysis suggested that the combination of TG and waist circumference further improved the diagnostic value for NAFLD. CONCLUSIONS: HTGW phenotype is associated with NAFLD risk in the general population, which may be a novel and accessible indicator for NAFLD screening.

Effects of Chang-Kang-Fang Formula on the Microbiota-Gut-Brain Axis in Rats With Irritable Bowel Syndrome.

Chang-Kang-Fang formula (CKF), a multi-herb traditional Chinese medicine, has been used in clinical settings to treat irritable bowel syndrome (IBS). Recent studies show that 5.0 g/kg/d CKF can alleviate the symptoms of IBS rats by modulating the brain-gut axis through the production of brain-gut peptides (BGPs), thus relieving pain, and reversing the effects of intestinal propulsion disorders. However, the exact mechanisms underlying the therapeutic effects of CKF in IBS remain unclear. The microbiota-gut-brain axis (MGBA) is central to the pathogenesis of IBS, regulating BGPs, depression-like behaviors, and gut microbiota. Given that CKF ameliorates IBS via the MGBA, we performed metabolomic analyses, evaluated the gut microbiota, and system pharmacology to elucidate the mechanisms of action of CKF. The results of intestinal tract motility, abdominal withdrawal reflex (AWR), sucrose preference test (SPT), and the forced swimming test (FST) showed that the male Sprague-Dawley rats subjected to chronic acute combining stress (CACS) for 22 days exhibited altered intestinal motility, visceral hypersensitivity, and depression-like behaviors. Treatment of IBS rats with CKF normalized dysfunctions of CACS-induced central and peripheral nervous system. CKF regulated BDNF and 5-HT levels in the colon and hippocampus as well as the expressions of the related BGP pathway genes. Moreover, the system pharmacology assays were used to assess the physiological targets involved in the action of CKF, with results suggesting that CKF putatively functioned through the 5-HT-PKA-CREB-BDNF pathway. LC-MS-based metabolomics identified the significantly altered 5-HT pathway-related metabolites in the CKF treatment group, and thus, the CKF-related signaling pathways were further examined. After pyrosequencing-based analysis of bacterial 16S rRNA (V3 + V4 region) using rat feces, the Lefse analysis of gut microbiota suggested that CKF treatment could induce structural changes in the gut microbiota, thereby regulating it by decreasing Clostridiales, and the F-B ratio while increasing the levels of Lactobacillus. Furthermore, the integrated analysis showed a correlation of CKF-associated microbes with metabolites. These findings showed that CKF effectively alleviated IBS, which was associated with the altered features of the metabolite profiles and the gut microbiota through a bidirectional communication along the microbiota-gut-brain axis.

Beneficial effect of simvastatin on human umbilical vein endothelial cells gap junctions induced by TNF-α.

Although simvastatin has been shown to inhibit vascular permeability, which might be amplified via gap junction intercellular communication (GJIC), the underlying mechanism of action remains unclear. In the present study, we investigated the effects and mechanisms of simvastatin on endothelial cells GJIC. Specifically, human umbilical vein endothelial cells (HUVECs) were stimulated with TNF-α (10 ng/mL) alone or in combination with simvastatin (5 µM), and their effects on vascular endothelial cell GJIC tested via the scrape loading/dye transfer (SL/DT) assay. Next, we performed immunofluorescence, real-time PCR and western blot assays to analyze expression of Cx37, Cx40 and Cx43 in HUVECs. Results showed that GJIC activity in HUVECs was markedly elevated in HUVECs treated with TNF-α in combination with simvastatin. In addition, simvastatin treatment significantly upregulated expression of Cx37 and Cx40 but downregulated Cx43 mRNAs and proteins. Taken together, these marked changes indicated that simvastatin exerts its regulatory effects on gap junction function by upregulating Cx37 and Cx40 and downregulating Cx43 expression.

Effect of dandelion root polysaccharide on the pasting, gelatinization, rheology, structural properties and in vitro digestibility of corn starch.

The influence of dandelion root polysaccharide (DRP) on the gelatinization properties and in vitro digestibility of corn starch was investigated. Pasting behaviors indicated that the addition of DRP led to an increase of the pasting temperature and a decrease of viscosity. Compared to native corn starch, the swelling power, solubility and content of amylose leaching were reduced as the DRP addition increased. Scanning electron microscopy (SEM) analysis showed that DRP was easily dispersed in the starchy matrix, and a more uniform structure was observed in corn starch/DRP pastes. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analyses confirmed that the crystal shape of the corn starch gels was not changed and no new groups were produced with increasing DRP concentration. Moreover, DRP could improve the fluidity of the gelatinized corn starch and reduce its digestibility. These findings provided fundamental information about DRP's application in the whole processing of corn starch.

Identifying an lncRNA-Related ceRNA Network to Reveal Novel Targets for a Cutaneous Squamous Cell Carcinoma.

A cutaneous squamous cell carcinoma (cSCC) derived from keratinocytes is the second most common cause of non-melanoma skin cancer. The accumulation of the mutational burden of genes and cellular DNA damage caused by the risk factors (e.g., exposure to ultraviolet radiation) contribute to the aberrant proliferation of keratinocytes and the formation of a cSCC. A cSCC encompasses a spectrum of diseases that range from recursor actinic keratosis (AK) and squamous cell carcinoma (SCC) in situ (SCCIS) to invasive cSCCs and further metastatic SCCs. Emerging evidence has revealed that lncRNAs are involved in the biological process of a cSCC. According to the ceRNA regulatory theory, lncRNAs act as natural miRNA sponges and interact with miRNA response elements, thereby regulating the mRNA expression of their down-stream targets. This study was designed to search for the potential lncRNAs that may become potential therapeutic targets or biomarkers of a cSCC. Considering the spirit of the study to be adequately justified, we collected microarray-based datasets of 19 cSCC tissues and 12 normal skin samples from the GEO database (GSE42677 and GSE45164). After screening the differentially expressed genes via a limma package, we identified 24 differentially expressed lncRNAs (DElncRNAs) and 3221 differentially expressed mRNAs (DEmRNAs). The miRcode, miRTarBase, miRDB and TargetScan databases were used to predict miRNAs that could interact with DElncRNAs and DEmRNAs. A total of 137 miRNA-lncRNA and 221 miRNA-mRNA pairs were retained in the ceRNA network, consisting of 31 miRNAs, 11 DElncRNAs and 155 DEmRNAs. For the functional analysis, the top enriched biological process was enhancer sequence-specific DNA binding in Gene Ontology (GO) terms. The FoxO signaling pathway, autophagy and cellular senescence were the top enrichment terms based on a Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The combination of a STRING tool and Cytoscape software (plug-in MCODE) identified five core mRNAs and built a core mRNA-associated ceRNA network. The expression for five identified core mRNAs and their related nine lncRNAs was validated using the external dataset GSE7553. Finally, one lncRNA HLA-F-AS1 and three mRNAs named AGO4, E2F1 and CCND1 were validated with the same expression patterns. We speculate that lncRNA HLA-F-AS1 may sponge miR-17-5p or miR-20b-5p to regulate the expression of CCND1 and E2F1 in the cSCC. The present study may provide potential diagnostic and therapeutic targets for cSCC patients.

PTIP Deficiency in B Lymphocytes Reduces Subcutaneous Fat Deposition in Mice.

Recent studies have predominantly focused on the role of B cells in metabolic diseases, yet the function of B cells in adipose homeostasis remains unclear. Pax transactivation domain-interacting protein (PTIP), a licensing factor for humoral immunity, is necessary for B cell development and activation. Here, using mice that lack PTIP in B cells (PTIP-/- mice), we explored the role of B cells in adipose homeostasis under physiological conditions. Fat deposition in 8-week-old mice was measured by micro-CT, and PTIP-/- mice presented a marked decrease in the deposition of subcutaneous adipose tissue (SAT). Untargeted lipidomics revealed that the triglyceride composition in SAT was altered in PTIP-/- mice. In addition, there was no difference in the number of adipocyte progenitor cells in the SAT of wild-type (WT) and PTIP-/- mice as measured by flow cytometry. To study the effects of steady-state IgM and IgG antibody levels on fat deposition, PTIP-/- mice were injected intraperitoneally with serum from WT mice once every 3-4 days for 4 weeks. The iSAT mass of the recipient mice showed no significant increase in comparison to the controls after 4 weeks of injections. Our findings reveal that PTIP plays an essential role in regulating subcutaneous adipocyte size, triglyceride composition, and fat deposition under physiological conditions by controlling B cells. The decreased subcutaneous fat deposition in PTIP-/- mice does not appear to be related to the number of adipocyte progenitor cells. The steady-state levels of IgM and IgG antibodies in vivo are not associated with the subcutaneous fat deposition.

Degradation of blue honeysuckle polysaccharides, structural characteristics and antiglycation and hypoglycemic activities of degraded products.

In this study, H2O2-Vc (hydrogen peroxide-ascorbic acid) oxidation system under 50 and 70 °C was developed to degrade blue honeysuckle polysaccharides. The results suggested that viscosity-average molecular weight was decreased and reducing sugar content was raised with the rise of time or temperature. The degradation was fitted to the second-order reaction kinetics. The gas chromatography revealed two degraded polysaccharides were consisted of six monosaccharides (Gal A, Rha, Ala, Gal, Glu, Man) with different ratios, and eight types of sugar residues were confirmed using nuclear magnetic resonance. Based on the linearity (R1), branching (R2), branch size (R3) calculation, PD70 (purified degraded polysaccharide at 70 °C) had a more linear structure and longer side chains comparing to PD50 (purified degraded polysaccharide at 50 °C). The absence of triple helical structure and sheet-like aggregation with rough surface were confirmed by the Congo red test and scanning electron. Rheological characterization proved the two degraded polysaccharides exhibited shear-thinning behavior and viscoelastic property. Besides, the two degraded polysaccharides displayed strong antiglycation activities, inhibitory effects against α-amylase and α-glucosidase, and exhibited competitive inhibitory kinetics. These findings support the potential application of blue honeysuckle polysaccharides as the treatment of diabetes.

Effect of Syringopicroside Extracted from Syringa oblata Lindl on the Biofilm Formation of Streptococcus suis.

Syringopicroside is a natural drug with antibacterial activity, which is the main ingredient of Syringa oblata Lindl (S. oblata). In order to further develop the application of S. oblata and evaluate the ability of syringopicroside against Streptococcus suis (S. suis), this investigation first applied an ultrasonic-assisted method to extract syringopicroside, and then response surface methodology (RSM) was performed to get the optimum condition. Based on RSM analysis, a second-order polynomial equation about the syringopicroside yield and four variables, including ultrasonic power, time, temperature, and liquid-to-solid ratio, was purposed. Through RSM prediction and model verification experiments, the optimum conditions were determined, as follows: ultrasonic time was 63 min, temperature was 60 °C, a liquid-to-solid ratio was set to 63 mL/g, and ultrasonic power was 835 W. Under this condition, a high syringopicroside yield was obtained (3.07 ± 0.13 mg/g), which was not significantly different with a predicated value. After separation and purification by HPD 500 microporous resin, then mass spectrum was applied to identify the main ingredient in aqueous extract. A minimal inhibitory concentration (MIC) assay revealed the value against S. suis of syringopicroside was 2.56 µg/µL and syringopicroside with sub-inhibitory concentrations that could effectively inhibit biofilm formation of S. suis. Besides, scanning electron microscopy analysis indicated syringopicroside could destroy the multi-layered aggregation structure of S. suis. Finally, molecular docking analysis confirmed that syringopicroside was combined with Orfy protein of S. suis through hydrogen bonds, hydrophobic interaction, and π-π stacking.

Characterization of selenized polysaccharides from Ribes nigrum L. and its inhibitory effects on α-amylase and α-glucosidase.

The polysaccharide from Ribes nigrum L. (RCP) was modified by nitric acid-sodium selenite method. After purification by Sepharose-6B, high purity native (PRCP) and three selenized polysaccharides (PRSPs) with different selenium contents were obtained. Compared with PRCP, PRSPs possessed the lower molecular weight, better water-solubility, physical stability and rheological properties. FT-IR and NMR spectra confirmed PRSPs had the characteristic absorption peaks of polysaccharides and the glycosidic bond types were not changed after selenylation modification, whereas the selenyl groups existing in PRSPs were mainly introduced at the C-6 position of sugar residue →4)-ß-d-Manp-(1→. Moreover, PRSPs displayed obviously smoother and smaller flaky structure than PRCP, and their inhibitory effects on α-amylase and α-glucosidase also were greater than PRCP. PRSPs exhibited a reversible inhibition on two enzymes in competitive manner and quenched their fluorescence through the static quenching mechanism. The polysaccharide-enzyme complex was spontaneously formed mainly driven by the hydrophobic interaction and hydrogen bonding.

Characterization, antioxidant and immunomodulatory effects of selenized polysaccharides from dandelion roots.

The polysaccharide (DRP) was gained from dandelion roots by ultrasonic-assisted enzymatic extraction (UAEE) followed by two-step column purification. Then selenylation of DRP has been accomplished by HNO3-Na2SeO3 method. sDRP-1 and sDRP-2 with the selenium content of 170 ± 1.13 and 710 ± 4.00 µg/g were prepared for further structural characterization and bioactivity determination. DRP, sDRP-1, and sDRP-2 were composed of the same monosaccharides in different molar ratios, and the molecular weights of DRP, sDRP-1 and sDRP-2 were 8700, 7900, and 5600 Da, respectively. Fourier transform infrared (FT-IR) spectra confirmed that DRP, sDRP-1, and sDRP-2 possessed similar functional groups. The results of Congo red test, X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that DRP, sDRP-1, and sDRP-2 had no three helix structure, did not form single crystal, and all belonged to amorphous morphology. sDRP-1 and sDRP-2 possessed greater antioxidant activities in vitro than the native polysaccharide DRP. At the same time, the selenized polysaccharides showed better immunomodulatory ability and could be used as new-type immunoenhancer. The present conclusions provided theoretical basis for the new application of dandelion polysaccharides and the development of dandelion resources.

Degradation models, structure, rheological properties and protective effects on erythrocyte hemolysis of the polysaccharides from Ribes nigrum L.

The polysaccharides from blackcurrant (Ribes nigrum L.) fruits were degraded by ultrasonic irradiation. Results showed that viscosity-average molecular weight decreased with increasing ultrasonic time or power. The degradation was fitted to the second-order kinetics model and midpoint chain scission model. Gas chromatographic analysis demonstrated that the native polysaccharide and three degraded polysaccharides were composed of the same monosaccharides but in different ratios. Fourier transform infrared and nuclear magnetic resonance spectroscopic analyses revealed the presence of α-, ß-pyranose rings and the same six sugar residues in the four blackcurrant polysaccharides. Compared to the native polysaccharide, three degraded polysaccharides displayed better rheological properties and stronger protective effects against erythrocyte hemolysis. Collectively, the results support the potential utility of blackcurrant polysaccharides as natural antioxidants.

Characterization and inhibitory activities on α-amylase and α-glucosidase of the polysaccharide from blue honeysuckle berries.

An acidic heteropolysaccharide HEP-2 was obtained from blue honeysuckle berry extracts after purification using Sepharose 6B and Sephadex G-200 column chromatography. The molecular weight of HEP-2, determined with high-performance gel permeation chromatography, was 3.01 × 106 Da. Fourier transform infrared spectroscopy, gas chromatography and nuclear magnetic resonance analyses revealed the presence of α-, ß-pyranose ring and six sugar residues in HEP-2. Amorphous aggregates of HEP-2 with irregular shape and lacking the triple helical structure were detected using the Congo red test, scanning electron and atomic force microscopy, and X-ray diffraction studies. Rheological characterization showed typical shear-thinning behavior and viscoelastic property of the polysaccharide. HEP-2 exerted significant inhibitory effects on α-amylase and α-glucosidase and displayed competitive inhibition kinetics. The collective results support the potential utility of HEP-2 as a hypoglycemic agent for enzyme-targeted treatment of diabetes or functional food.

Preparation, characteristics, and antioxidant activities of carboxymethylated polysaccharides from blackcurrant fruits.

In the present study, the native polysaccharide (RNP) extracted from blackcurrant fruits was carboxymethylated. Physicochemical characteristics and antioxidant activities in vitro of RNP and three carboxymethylated polysaccharides (CRNPs) were determined. GC analysis proved that RNP and CRNPs were composed of the same six monosaccharides (galacturonic acid, rhamnose, arabinose, mannose, glucose and galactose), but the molar ratios of monosaccharides were different. HPLC demonstrated that the molecular weights of CRNPs were improved. The assays of the antioxidant properties indicated that CRNPs possessed stronger scavenging activities on radicals (hydroxyl and superoxide radicals) and better anti-lipid peroxidation activities, as well as better protection effects on erythrocyte hemolyses in vitro compared with RNP. The activities of CRNPs were significantly enhanced with the increase of the degree of substitution (DS). These results proved that the carboxymethylation could effectively increase the antioxidant activities of the polysaccharide.