Structure characterization and biological activities of a pectic polysaccharide from cupule of Castanea henryi

Influence of Temperatures on Physicochemical Properties and Structural Features of Tamarind Seed Polysaccharide

Due to the high content of impurities such as proteins in tamarind seed polysaccharide (TSP), they must be separated and purified before it can be used. TSP can disperse in cold water, but a solution can only be obtained by heating the mixture. Therefore, it is important to understand the dispersion and dissolution process of TSP at different temperatures to expand the application of TSP. In this study, pasting behavior and rheological properties as a function of temperature were characterized in comparison with potato starch (PS), and their relationship with TSP molecular features and microstructure was revealed. Pasting behavior showed that TSP had higher peak viscosity and stronger thermal stability than PS. Rheological properties exhibited that G' and G'' of TSP gradually increased with the increase in temperature, without exhibiting typical starch gelatinization behavior. The crystalline or amorphous structure of TSP and starch was disrupted under different temperature treatment conditions. The SEM results show that TSP particles directly transformed into fragments with the temperature increase, while PS granules first expanded and then broken down into fragments. Therefore, TSP and PS underwent different dispersion mechanisms during the dissolution process: As the temperature gradually increased, TSP possibly underwent a straightforward dispersion and was then dissolved in aqueous solution, while PS granules initially expanded, followed by disintegration and dispersion.

Fractionation and characterization of sodium carbonate-soluble fractions of cell wall pectic polysaccharides involved in the rapid mealiness of 'Hongjiangjun' apple fruit

Apple flesh tends to turn mealy and textural deterioration commonly occurs during storage. The comparative investigation of three sub-fractions separated from sodium carbonate-soluble pectin (SSP) of 'Hongjiangjun' apples between crisp and mealy stages was performed to unveil the textural alterations related to mealiness. In situ immunofluorescence labelling showed that galactans declined in parenchyma cell walls during the fruit mealiness. FTIR analysis, monosaccharide compositions and structural polymers configurated that loss of rhammogalacturonan-I (RG-I) from SSP sub-fragments (SC0.0-P and S-M0.0-P) might be closely involved in the mealiness. The NMR spectroscopy revealed that loss of the substituted galactans from α-Rhap residues repeat unit in SC0.0-P constituting RG-I in crisp stage that subsequently converted to S-M0.0-P in mealy stage might be closely associated with the modifications of pectin in cell walls during mealiness. These findings provided novel evidence for understanding the underlying modifications of SSP polymers during the mealiness of 'Hongjiangjun' apples.

Characterization and Function Analysis of Soluble Dietary Fiber Obtained from Radish Pomace by Different Extraction Methods

Soluble dietary fiber (SDF) benefits human health, and different extraction methods might modify the structure and functions of the SDFs. Radish is rich in dietary fiber. To assess the impact of various extraction techniques on the properties and functions of radish SDF, the SDFs were obtained from white radish pomace using alkaline, ultrasonic-assisted, and fermentation-assisted extraction methods. Analysis was conducted on the structure, physicochemical characteristics, thermal properties, and functional attributes of the SDFs. The study revealed that various extraction techniques can impact the monosaccharides composition and functionality of the SDFs. Compared with the other two extraction methods, the surface structures of SDFs obtained by fermentation-assisted extraction were looser and more porous, and the SDF had better water solubility and water/oil holding capacity. The adsorption capacities of glucose and cholesterol of the SDFs obtained from fermentation-assisted extraction were also improved. Wickerhamomyces anomalus YFJ252 seems the most appropriate strain to ferment white radish pomace to acquire SDF; the water holding, oil holding, glucose absorption capacity, and cholesterol absorption capacity at pH 2 and pH 7 have a 3.06, 1.65, 3.19, 1.27, and 1.83 fold increase than the SDF extracted through alkaline extraction method.

Hepatoprotective effects of peach gum polysaccharides against alcoholic liver injury: moderation of oxidative stress and promotion of lipid metabolism

Natural polysaccharides extracted from plants have received increasing attention due to their rich bioactivity. In our study, peach gum polysaccharides (PGPs) were extracted by water extraction-alcohol precipitation method. PGPs are typical pyranose polysaccharides with a mean molecular weight of 3.68 × 106 g/mol. The antioxidant activity and hepatoprotective capacity of PGPs were studied. In vitro, assays showed that PGPs scavenged DPPH, OH, and O2- in a dose-dependent manner. PGPs exhibited antioxidative properties against alcohol-induced HL7702 cells, as evidenced by the normalization of MDA, SOD, ROS, and GSH levels. To further elucidate the hepatoprotective mechanism of PGPs, we carried out in vivo experiments in male mice. PGPs exerted hepatoprotective effects in alcohol liver disease (ALD) mice by exerting antioxidant effects, decreasing the inflammatory response and modulating lipid metabolism. In addition, metabolomic analysis indicated that PGPs mainly regulate D-glutamine and D-glutamate metabolism, alanine, aspartate and glutamate metabolism, and arginine biosynthesis to promote hepatic metabolism and maintain body functions. Overall, this study revealed that the hepatoprotective mechanism of PGPs against ALD might be associated with the regulation of oxidative stress and lipid metabolism.

Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

The structures of two acidic polysaccharides from Gardenia jasminoides and their potential immunomodulatory activities

This study identified two homogeneous acidic polysaccharides from Gardeniae fructus, GJP50-3 and GJP50-4, which exhibited potential immunomodulatory activities in macrophage activation assays, via liquid-chip technology, and in a zebrafish model. Monosaccharide composition analysis and gel permeation chromatography revealed that GJP50-3 and GJP50-4 were composed of Rha, GalA, Glc, Gal, and Ara in specific ratios and had molecular weights of 91.5 kDa and 140.3 kDa, respectively. Based on FT-IR, GC-MS, and NMR analyses, these polysaccharides were identified as typical pectin polysaccharides with methylation degrees of 24.7 % and 21.4 %, respectively. The primary structures of GJP50-3 and GJP50-4 included linear HG domains and branched RG-I domains with arabinans and AG side chains. In vitro, GJP50-3 and GJP50-4 could stimulate NO release and increase the secretion of TNF-α in a RAW 264.7 macrophage model. Luminex liquid suspension chip detection revealed that GJP50-3 significantly promoted the secretion of multiple interleukins [IL-6, IL-9, IL-10, IL-12 (p40), IL-12 (p70), IL-13], TNF-α, and chemokines (G-CSF, GM-CSF, MCP-1 and RANTES). In vivo, these polysaccharides could also increase NO release and neutrophil count in a zebrafish model. These findings suggested that GJP50-3 and GJP50-4 might have the potential to be used as immunomodulators in the food and pharmaceutical industries.

Ultrasound-Microwave Combined Extraction of Novel Polysaccharide Fractions from Lycium barbarum Leaves and Their In Vitro Hypoglycemic and Antioxidant Activities

Ultrasound-microwave combined extraction (UMCE), gradient ethanol precipitation, chemical characterization, and antioxidant and hypoglycemic activities of Lycium barbarum leaf polysaccharides (LLP) were systematically studied. The optimal conditions for UMCE of LLP achieved by response surface method (RSM) were as follows: microwave time of 16 min, ultrasonic time of 20 min, particle size of 100 mesh, and ratio of liquid to solid of 55:1. Three novel polysaccharide fractions (LLP₃₀, LLP₅₀, LLP₇₀) with different molecular weights were obtained by gradient ethanol precipitation. Polysaccharide samples exhibited scavenging capacities against ABTS and DPPH radicals and inhibitory activities against α-glucosidase and α-amylase. Among the three fractions, LLP₃₀ possessed relatively high antioxidant and hypoglycemic activities in vitro, which showed a potential for becoming a nutraceutical or a phytopharmaceutical for prevention and treatment of hyperglycemia or diabetes.

The Complete Chloroplast Genome Sequence of Machilus chuanchienensis (Lauraceae): Genome Structure and Phylogenetic Analysis

Machilus chuanchienensis is an ecological tree distributed in southwestern China. It has a significant valuation with making Hawk tea using its leaves, an ethnic traditional tea-like beverage with a long history in Chinese tea culture. The whole chloroplast (cp) genome is an ideal model for the phylogenetic study of Lauraceae because of its simple structure and highly conserved features. There have been numerous reports of complete cp genome sequences in Lauraceae, but little is known about M. chuanchienensis. Here, the next-generation sequencing (NGS) was used to sequence the M. chuanchienensis cp genome. Then, a comprehensive comparative genome analysis was performed. The results revealed that the M. chuanchienensis's cp genome measured 152,748 base pairs (bp) with a GC content of 39.15% and coded 126 genes annotated, including comprising eight ribosomal RNA (rRNA), 36 transporter RNA (tRNA), and 82 protein-coding genes. In addition, the cp genome presented a typical quadripartite structure comprising a large single-copy (LSC; 93,811) region, a small single-copy (SSC; 18,803) region, and the inverted repeats (IRs; 20,067) region and contained 92 simple sequence repeat (SSR) locus in total. Phylogenetic relationships of 37 species indicated that M. chuanchienensis was a sister to M. balansae, M. melanophylla, and M. minutiflora. Further research on this crucial species may benefit significantly from these findings.

In Vitro Digestion and Fecal Fermentation of Peach Gum Polysaccharides with Different Molecular Weights and Their Impacts on Gut Microbiota

In the present study, we investigated the in vitro digestion and fermentation characteristics of three peach gum polysaccharides (PGPs) of different molecular weights; i.e., AEPG2 (1.64 × 107 g/mol), DPG2 (5.21 × 105 g/mol), and LP100R (8.50 × 104 g/mol). We observed that PGPs were indigestible during the oral, gastrointestinal, and intestinal stages. However, they were utilized by the gut microbiota with utilization rates in the order of DPG2 > AEPG2 > LP100R. Furthermore, arabinose in PGPs was preferentially utilized by the gut microbiota followed by galactose and xylose. Fermentation of peach gum polysaccharides could significantly increase the production of short-chain fatty acids (SCFAs), especially n-butyric acid. In addition, PGPs with different molecular weights values were predominantly fermented by different bacterial species. AEPG2 and DPG2 were fermented by the Bacteroidetes bacteria Bacteroides, while the dominant n-butyrate-producing bacteria was Faecalibacterium. While the LP100R was fermented by Bacteroides, Parabacteroides, Phascolarctobacterium, Dialister, Lachnospiraceae, and Blautia, the dominant n-butyrate-producing bacteria was Megamonas. These results indicated that PGPs are potential prebiotics for the food industry.

Ultrasonication, immune activity, and photocrosslinked microgel formation of pectic polysaccharide isolated from root bark of Ulmus davidiana var. japonica (Rehder) Nakai

The root bark of Ulmus davidiana var. japonica (Rehder) Nakai (Japanese elm) has been used for inflammatory disease treatments. In this work, we isolated pectic polysaccharides from the root bark of U. davidiana (UDP) and explored the immune activities of intact and ultrasonicated UDP on human macrophages. The UDP-treated macrophages showed a proinflammatory response, indicating classical activation via Toll-like receptor-mediated recognition. For hydrogel formation, the ultrasonicated UDP was modified with methacrylate groups, then subjected to photocrosslinking. The formed bulk hydrogel was pulverized into microgels by homogenization, and the microgel size was modulated for macrophage phagocytosis. The UDP microgel-treated macrophages displayed microgel internalization and classical activation that involved upregulation of M1 polarization markers (IL6, TNF-α, and CCR7), indicating that the microgel can be used as a carrier for macrophage-targeted drug delivery.

Structure and In Vitro Fermentation Characteristics of Polysaccharides Sequentially Extracted from Goji Berry (Lycium barbarum) Leaves

Herein, the chelating agent-soluble fraction (CA), sodium carbonate-soluble fraction (SC), and sodium hydroxide-soluble fraction (SH) were sequentially extracted from the cell wall of goji berry (Lycium barbarum) leaves. Furthermore, SC was purified with Q-Sepharose fast flow resin to obtain the neutral sugar fraction (SC-I) and acid sugar fraction (SC-II). Physicochemical properties of polysaccharides were characterized by high-performance anion-exchange chromatography with pulsed amperometry detection, size exclusion chromatography-multi-angle laser light scattering, Fourier transform infrared spectroscopy, nuclear magnetic resonance, and atomic force microscopy analysis. Additionally, the impact of polysaccharides on modulating human gut microbiota was investigated by in vitro fermentation. A high amount of galacturonic acid (GalA) in CA showed that it was an aggregation of linear homogalacturonan. SC was the main pectic polysaccharide fraction and rich in neutral sugars. SC-I was the neutral sugar fraction with an extremely high molecular weight (2.055 × 10⁶ Da), while SC-II was the acid sugar fraction with a low molecular weight (1.766 × 10⁵ Da). SH seemed like a mixture of pectin and hemicellulose. All the five polysaccharides significantly (P < 0.05) increased the abundance of Bacteroides, Bifidobacteria, and Lactobacilli. To the best of our knowledge, this is the first report on the structure and fermentation characteristics of goji berry leaf polysaccharides, which is meaningful to provide a structural basis for further bioactivity research.

Effects of Different Bud Thinning Methods on Nutritional Quality and Antioxidant Activities of Fruiting Bodies of Pleurotus eryngii

The cultivation of Pleurotus eryngii was studied by different methods, such as puncturing and fixed-point mushroom production, shading treatment at the top of the bag, and pulling the top of the bag. The agronomic characters, yield, nutritional components, and antioxidant activities in vitro of fruiting bodies of P. eryngii were determined. The results showed that the number of buds in the perforated treatment was less than that in the production method of traditional fruiting bodies to a certain extent. When a circular hole with a diameter of 1.5 cm was drilled in the perforated treatment, the number of buds was 5, which was less than that in the control group. The efficiency of artificial removal of buds was significantly higher than that of the control group, but the harvesting date was longer than that of other methods. The number of buds in shading treatment and bag opening treatment was significantly less than that in the control group, which could effectively control the number of buds and reduce the cost of manpower and material resources. In terms of nutritional components, the A3 treatment group with a hole diameter of 1.0 cm and a quantity of one had the highest crude protein content of 151.34 g, and a significant difference was observed in crude fiber content compared with other treatments. The extraction rate of B5 crude polysaccharide was the highest, and the extraction rate was 12.90%. The antioxidant activities in vitro increased with the increase of crude polysaccharide concentration. Using A3 treatment to cultivate fruiting bodies is conducive to meeting people's requirements for improving quality of life.

Structure characterization and bioactivity of neutral polysaccharides from different sources of Polygonatum Mill

Polygonati rhizoma (PR), a traditional medical and edible product, is rich in polysaccharides and exhibits physiological activity, including antioxidant, hypoglycemic and hypolipidemic properties. Neutral polysaccharides have been reported to be one of the main active ingredients of Polygonatum, with many of these fractions being responsible for the biological activity. This behavior was shown to be closely connected to the chemical structure, monosaccharide composition, and glycosidic bond type. There are few reports on the chemical constituents of the neutral polysaccharides from different sources of PR. In this study, neutral polysaccharides of PR from four different regions of China (Chun'an (Zhejiang), Xixia (Henan), Danfeng (Shanxi), and Pan'an (Zhejiang)), named CAZJ, XXHN, DFSX, and PAZJ, respectively, were isolated by anion-exchange and gel-permeation chromatography. Structures of the four polysaccharides were investigated. The results showed that all of them were mainly glucose and mannose, while the monosaccharide composition and content of polysaccharides from different sources varied. The molecular weights of CAZJ, XXHN, DFSX, and PAZJ were 14.119, 22.352, 18.127, and 15.699 kDa, respectively. Infrared spectra illustrated the existence of α-glycosidic bond and β-glycosidic bond in the polysaccharides. CAZJ, XXHN, and DFSX possessed a pyranose ring structure, whereas PAZJ had a furanose ring structure. Congo red test indicated that XXHN, DFSX, and PAZJ had a triple-helix structure. X-ray diffraction showed that the polysaccharides consisted of crystalline and amorphous regions. All four polysaccharides exhibited different degrees of antioxidant and hypoglycemic activities with a dose-dependent manner in the 1.0-10.0 mg/mL concentration range. Correlation analysis revealed that the bioactivities of polysaccharides was significantly related to monosaccharide composition, uronic acid, and protein content. The results suggested that neutral polysaccharides could be used as potential natural antioxidants and hypoglycemic agents for functional and nutraceutical applications.

Effects of multi-frequency ultrasonic on the physicochemical properties and bioactivities of polysaccharides from different parts of ginseng

The effect of multi-frequency ultrasonic extraction (MUE) on the yields, physicochemical properties, antioxidant and α-glucosidase inhibitory activities of polysaccharides (GPs) from different parts of ginseng were compared. Results demonstrated that yields of polysaccharides from different parts were found to vary significantly differences, in the order of roots (M-GRPs) > flowers (M-GFPs) > leaves (M-GLPs). Compared with heat reflux extraction, MUE not only increased the yield of GPs by up to 9.14%-210.87%, with higher uronic acid content (UAC: increased by 4.99%-53.48%), total phenolics content (TPC: increased by 7.60% to 42.61%), total flavonoids content (TFC: increased by 2.52%-5.45%), and lower molecular weight (Mw: reduced by 6.51%- 33.08%) and protein content (PC: reduced by 5.15%-8.95%), but also improved their functional properties and bioactivities. All six purified polysaccharides extracted by MUE were acidic pyran polysaccharide with different monosaccharide composition, possessed remarkable antioxidant and α-glucosidase inhibitory activities. Especially, M-GFP-1 exhibited the highest bioactivities, illustrated that the activities were highly correlated with UAC and TPC, Mw, and triple helical structure. These results indicate that MUE was an efficient technique for improving yields, physicochemical and functional properties and enhancing biological activities of polysaccharide.

Extraction and identification of proanthocyanidins from the leaves of persimmon and loquat

Proanthocyanidins is flavan-3-ol polymers with many activities which attracted a lot of attention. However, most of the proanthocyanidins come from fruits and seeds, resulting in higher costs. The extraction of proanthocyanidins from leaves that were trimmed as wastes from fruit trees is of good economic benefits. The proanthocyanidins in persimmon leaves and loquat leaves were extracted and purified. The purity of persimmon and loquat leaves were 85.33 ± 0.11% and 88.45 ± 0.96% with yield of 3.40% and 2.37% respectively. Detailed structure information was analyzed. Persimmon leaves proanthocyanidins mainly consist of catechin with B-type link along with a small portion of gallocatechin, catechin gallate and A-type link. Loquat leaves proanthocyanidins consist of catechin, gallocatechin, gallocatechin gallate and afzelechin with B-type link along with a small portion of A-type link. The α-amylase inhibition effect of the two leaves was analyzed. Persimmon leaves proanthocyanidins and loquat leaves proanthocyanidins were two mixed-type inhibitors to α-amylase.

Purification, structural characterization and antioxidant activity of a new arabinogalactan from Dorema ammoniacum gum

Gum ammoniacum is a polymer obtained from Dorema ammoniacum and its medicinal use was already known to the ancient times. In this study, a new D. ammoniacum carbohydrate (DAC-1) with a molecular weight of 27.1 kDa was extracted by hot water and then purified on DEAE-52-cellulose and Sephadex G-100 columns. The structural features of DAC-1 were investigated by partial acid hydrolysis, fourier-transform infrared spectroscopy (FT-IR), methylation, gas chromatography-mass spectrometry (GC-MS), gas chromatography-flame ionization detection (GC-FID), and 1D and 2D nuclear magnetic resonance spectroscopy (1D & 2D NMR). The results indicated that DAC-1 was an arabinogalactan including galactose, arabinose, rhamnose, glucuronic acid and 4-O-methyl-β-d-glucopyranosyl uronic acid (meGlcpA) with a relative percentage of 44.63%, 23.30%, 13.46%. 12.47%, and 6.14%. The structure units of DAC-1 were elucidated as 3,1)-β-_D-Galp-(6 → 1)-β-_D-Galp-(3,6 → containing four branch chains of →1,6)-β-_D-Galp-(3 → 1)-α-_L-Araf-(5 → 1)-β-_D-GlcpA-(4 → 1)-α-_L-Rhap-T (two times), →1,6)-β-_D-Galp-(3→1)-β-_D-Galp-(3 → 1)-β-_D-Galp-(3 → 1)-β-_D-Galp-(3  →  1)-α-_L-Araf-T and →1,6)-β-_D-Galp-(3 → 1)-α-_L-Araf-(5 → 1)-β-_D-meGlcpA-T. X-ray diffraction (XRD) pattern indicated a semi-crystalline structure. Thermal behavior of the polysaccharide was evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and revealed temperatures higher than 200 °C as dominant region of weight loss. DAC-1 showed acceptable antioxidant activity when analyzed by DPPH, ABTS, FRAP, and OH radical removal methods.

Structural characterization, anti-inflammatory and glycosidase inhibitory activities of two new polysaccharides from the root of Pueraria lobata

Diabetes seriously endangers public health and brings a heavy economic burden to the country. Inflammation is one of the main inducing factors of type-2 diabetes (T2D) and may cause some complications of diabetes, such as diabetic encephalopathy and peripheral neuropathy. In-depth research and development of drugs to cure diabetes and complications are of great significance. Pueraria lobate is a medicinal herb used in several countries to treat many diseases. Here, two new polysaccharides (PLB-1-1 and PLB-1-2) were isolated and purified from the root of Pueraria lobata with molecular weights of 9.1 × 10³ Da and 3.8 × 10³ Da, respectively. The structure was evaluated by monosaccharide composition, GC-MS and NMR spectroscopy. It was determined that PLB-1-1 comprised →4)-α-d-Glcp-(1→, α-d-Glcp-(1→, →6)-β-d-Galp-(1→, →3)-α-l-Araf-(1→, →3,6)-β-d-Manp-(1→ and →4,6)-β-d-Manp-(1→, and PLB-1-2 consisted of →4)-α-d-Glcp-(1→, β-d-Glcp-(1→, →4,6)-β-d-Glcp-(1→, →3,6)-β-d-Manp-(1→ and α-l-Fucp-(1→. Furthermore, both PLB-1-1 and PLB-1-2 showed anti-inflammatory and inhibitory activities of α-glucosidase and α-amylase in vitro. Therefore, the new polysaccharides, i.e., PLB-1-1 and PLB-1-2, may be considered candidates for the treatment of diabetes and its related complications.

Through the extraction, isolation and purification of Pueraria lobata, we identified two new polysaccharides with molecular weights of 9.1 × 10³ Da and 3.8 × 10³ Da, and found that they have excellent anti-inflammatory and glycosidase inhibitory effects.

New function of polysaccharide from Rubus chingii Hu: protective effect against ethyl carbamate induced cytotoxicity

BACKGROUND

Rubus chingii Hu is a widely cultivated fruit in China and has declared multiple bioactivities including antioxidative activity. Ethyl carbamate (EC), mostly found in fermented food and alcoholic beverages, is a recognized human carcinogen, and researchers have proposed the correlation between oxidative stress and its toxicity. This study acquired the polysaccharide from R. chingii (RP) and explored its effect on EC-induced cytotoxicity using Caco-2 cells as the cell model.

RESULTS

Results showed that RP exhibited protection against EC-induced toxicity by repairing redox imbalance as indicative of mitigated mitochondrial membrane potential collapse, attenuated reactive oxygen species overproduction, and impeded glutathione depletion. Moreover, the structural features of RP were characterized and revealed that it was mainly constituted by galacturonic acid and arabinose, with an average molecular weight of 7.039 × 10⁵  g mol^-1 .

CONCLUSION

Overall, our results provided a new approach dealing with the toxicity caused by EC from the perspective of oxidative stress and described a new potential healthy value of R. chingii Hu, which could contribute to the development of a promising dietary supplement and functional food. © 2020 Society of Chemical Industry.

Post-screening characterization of an acidic polysaccharide from Echinacea purpurea with potent anti-inflammatory properties in vivo

We extracted and purified three polysaccharides from Echinacea purpurea using pectinase-assisted extraction to obtain crude preparations and optimized the method using an orthogonal analysis. We obtained three polysaccharide fractions (EPPS-1, -2 and -3) using DEAE ion exchange and gel filtration chromatography. The homogeneity of the fractions was confirmed using high performance gel permeation chromatography. EPPS-3 administered to mice in a LPS-induced septicemia model effectively counteracted the effects of LPS resulting in significantly less lung damage. This trend was also seen in the serum and lung cytokine levels where EPPS-3 significantly decreased the levels of TNF-α and IL-6 and increased IL-10. Particularly, we fully characterized the structure of the EPPS-3 polysaccharide using a series of technologies. This polysaccharide structure was mainly composed of →4)-α-Glcp-(1→, →4)-α-Galp-(1→, T-α-Araf-(1→, →3,4)-β-GalpA-(1→ glycosidic linkages at a certain proportion. In sum, EPPS-3, with a clear structure, has potent anti-inflammatory activities and is a candidate for further development as an anti-inflammatory agent for clinical development.

The Role of Reactive Oxygen Species in Tumor Treatment and its Impact on Bone Marrow Hematopoiesis

Reactive oxygen species (ROS), an important molecule inducing oxidative stress in organisms, play a key role in tumorigenesis, tumor progression and recurrence. Recent findings on ROS have shown that ROS can be used to treat cancer as they accelerate the death of tumor cells. At present, pro-oxidant drugs that are intended to increase ROS levels of the tumor cells have been widely used in the clinic. However, ROS are a double-edged sword in the treatment of tumors. High levels of ROS induce not only the death of tumor cells but also oxidative damage to normal cells, especially bone marrow hemopoietic cells, which leads to bone marrow suppression and (or) other side effects, weak efficacy of tumor treatment and even threatening patients' life. How to enhance the killing effect of ROS on tumor cells while avoiding oxidative damage to the normal cells has become an urgent issue. This study is a review of the latest progress in the role of ROS-mediated programmed death in tumor treatment and prevention and treatment of oxidative damage in bone marrow induced by ROS.

Structural characteristics and enhanced biological activities of partially degraded arabinogalactan from larch sawdust

Larch arabinogalactan (AG), extracted from Larix gmelinii sawdust, was depolymerized by H₂O₂ oxidation and purified by gel column to yield a novel degraded fraction (AGD2). The structural analysis indicated AGD2 had lower arabinose content and molecular weight compared with AG, in which the ratio of galactose and arabinose was changed from 7:3 to 16:1, the molecular weight was decreased from 50.2 kDa to 3.7 kDa, and the chain conformation spread from highly branched structure to flexible strand. It was one kind of β-D-(1 → 3)-galactan with fewer β-D-(1 → 6)-Galp side branches at O-6 position. Further, the results of the Gal-3 binding and immunomodulatory assay suggested that the unbinding force of AGD2 onto Gal-3 was as twice as AG to be 76 ± 11 pN at the loading rate of 0.15 μm/s. It could better promote the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) than AG in a dose-dependent manner.

Chemical characteristics and cytoprotective activities of polysaccharide fractions from Athyrium Multidentatum (Doll.) Ching

Five polysaccharide fractions (PS-1, PS-2, PS-3, PS-4 and PS-5) were successfully isolated from Athyrium Multidentatum (Doll.) Ching by anion-exchange column chromatography. Their in vitro cytoprotective activities and the underlying mechanisms were explored in this paper. Chemical analysis suggested that the five polysaccharide fractions were heteropolysaccharides with different molecular weights and monosaccharide compositions. Treatment with these polysaccharide fractions could increase cell viabilities, superoxide dismutase/catalase activities, nitric oxide contents, mitochondrial membrane potential levels and Bcl-2/Bax ratios, and reduce cell apoptosis, intracellular reactive oxygen species production and malondialdehyde contents in H2O2-damaged cells. Moreover, these polysaccharide fractions enhanced the mRNA expression levels of PI3K, Akt, FOXO3a, Nrf2 and HO-1 and PS-4 exhibited the most powerful effects on the mRNA expression of these genes. Current findings suggested that the polysaccharide fractions decreased H2O2-induced apoptosis of HUVECs. The activation of PI3K/Akt/FOXO3a and Nrf2/HO-1 signaling pathways might be involved in the protective mechanisms of the active fractions. The polysaccharides might be one of the key bioactive ingredients of Athyrium Multidentatum (Doll.) Ching for the treatment of oxidative damage.

Allelopathic Effects of Castanea henryi Aqueous Extracts on the Growth and Physiology of Brassica pekinensis and Zea mays

The present study investigated the allelopathic effects of aqueous extracts of Castanea henryi litter on the growth and physiological responses of Brassica pekinensis and Zea mays. Treatment with high concentrations of leaf extract (0.05 g/ml for B. pekinensis and 0.10 g/ml for Z. mays) significantly increased malonaldehyde content and reduced seed germination, seedling growth, chlorophyll content, and the activity levels of antioxidant enzymes. These effects generally increased with increasing extract concentration. However, in Z. mays, low extract concentrations actually promoted seed germination, shoot growth, chlorophyll content, and antioxidant enzyme activity. The allelopathic effects of the various C. henryi extracts decreased as follows: leaf extract > twig extract > shell extract. Eleven potential allelochemicals including rutin, quercetin, luteolin, procyanidin A2, kaempferol, allantoin, propionic acid, salicylic acid, jasmonic acid, methylmalonic acid, and gentisic acid were identified in the leaves of C. henryi which were linked to the strongest allelopathic effects. These findings suggest that the allelopathic effects of C. henryi differ depending on receptor plant species, and that leaves are the most allelopathic litter in C. henryi.

Physicochemical characterization of galactomannans extracted from seeds of Gleditsia sinensis Lam and fenugreek. Comparison with commercial guar gum

Gleditsia sinensis, fenugreek and guar galactomannans (referred to as GSG, FG, and GG) were extracted from their gums and investigated using various techniques. Mannose to galactose ratios were 3.55, 1.11, and 1.65, respectively. The intrinsic viscosity of GSG was very close to that of GG, while that of FG was the lowest one. This was attributed to the influence of high galactose substitution of FG on the mannan backbone, which induced a lower chain dimension due to intermolecular entanglement. High degrees of substitution and high temperatures contributed to improving the solubility of galactomannan. Rheological behavior indicated that GG had the highest apparent viscosity, yet the power-law model could well-fitted the flow curves of GSG and FG, but not GG. Through morphological observations, the extracted galactomannans exhibited rod-like structure in deionized water and showed fibrous filament network structure after dehydration by freeze-drying. The thermal behavior was greatly influenced by the degree of side groups and Mw of galactomannans.

Deproteinization of four macroporous resins for rapeseed meal polysaccharides

In this study, the adsorption/desorption characteristics of rapeseed meal polysaccharides extract on four resins (HP-20, D3520, XAD-16, and AB-8) were evaluated. The results indicated that HP-20 resin had the best purification effect. Based on static adsorption test, the kinetics and isotherms of the four resins for protein and polysaccharide were investigated. The adsorption test showed that the pseudo-second-order kinetics model and the Freundlich isotherm model were more suitable for explanation of the adsorption process for protein and polysaccharide. Static desorption test showed that the highest protein desorption ratios of HP-20, D3520, and AB-8 resins could be obtained with 60% ethanol solution as eluate, and the highest protein desorption ratios of XAD-16 resin could be obtained with 40% ethanol solution as eluate. Dynamic adsorption/desorption tests of HP-20 resin showed that the deproteinization ratio was 91% and the polysaccharide recovery ratio was 62% when the treatment amount was 1.5 BV. Compared with three traditional methods, HP-20 resin adsorption method that the deproteinization ratio was 82% was more potent than the three traditional methods for purifying polysaccharides from rapeseed meal. In addition, UV/vis spectroscopy showed that most of the protein was absorbed by resins, and FT-IR spectroscopy indicated that the purity of the polysaccharide after purification was improved. Rapeseed meal polysaccharides could be effectively deproteinized using HP-20 resin, and it was suitable for purifying polysaccharides from rapeseed meal.

Novel Antioxidant, Anti-α-Amylase, Anti-Inflammatory and Antinociceptive Water-Soluble Polysaccharides from the Aerial Part of Nitraria retusa

In this paper, water-soluble polysaccharides (named as NRLP) were extracted from Nitraria retusa leaves. The main structural features of NRLP were determined by High-pressure size exclusion chromatography, Fourier transform infrared and Gas Chromatography/Mass Spectrometry-Electronic Impact analysis. The in vitro and in vivo biological potential of NRLP were evaluated by measuring its antioxidant (•OH and DPPH• scavenging, total antioxidant capacity), anti-α-amylase as well as anti-inflammatory and antinociceptive activities in a mice model. NRLP was composed of Rha (33.7%), Gal (18.1%), GalA (15.0%), Glc (13.3%), Ara (13.3%), Xyl (3.8%), and GlcA (2.8%) and showed a Molecular Weight (Mw) of 23.0 kDa and a polydispersity index (PDI) of 1.66. The investigations highlighted a significant antioxidant activity (IC50 = 2.4-2.6 mg/mL) and an inhibition activity against α-amylase (IC50 = 4.55 mg/mL) in a dose-dependent manner. Further, NRLP revealed interesting anti-edematous effects and antinociceptive activities (both > 70%). These results open up new pharmacological prospects for the water-soluble polysaccharides extracted from Nitraria retusa leaves.

Volatile Compounds Are Involved in Cellular Crosstalk and Upregulation

Cell-cell cross talk is of great importance in cancer research due to its major role in proliferation, differentiation, migration, and influence on the apoptotic pathway. Different cell-cell communication mechanisms have come mainly from proteomic and genomic approaches. In this paper, a new route is reported for cross talk between cancer cells that occurs, even when they are far away from each other. Single-cell and culture analysis shows that upregulation of cancer cells emits hundreds of volatile organic compounds (VOCs) into their headspace. Part of the VOCs remains without any change, disregarding the biological environment around it. The other part of the VOCs is exchanged between monocultures of the cells as well as between co-cultures of the cells with no physical contact between them, leading to different changes in growth than when left on their own. The chemical nature and composition of these VOCs have been determined and are discussed herein. Cell-to-cell cross talk has the advantage of being suitable for transfer/diffusion over relatively long distances. It would thus be expected to serve as a shuttling pad toward the development of advanced approaches that could enable very early detection of cancer and/or monitoring of metastasis and related cancer therapy.

Comparison of citrus pectin and apple pectin in conjugation with soy protein isolate (SPI) under controlled dry-heating conditions

In this study, we selected two most commonly-available commercial pectin, i.e. citrus pectin and apple pectin as the grafting polysaccharides to prepare soy protein isolate-pectin conjugates. Despite the similar degrees of methoxylation and acetylation for two pectin samples, apple pectin showed much more complex structures compared to citrus pectin, with a 2.20-fold higher molecular weight and large numbers of side chains. The conjugates were prepared under controlled dry-heating conditions and achieved the degree of graft of 25.00% and 21.85% for citrus and apple pectin, respectively. Formation of the conjugates was further confirmed by SDS-PAGE gel electrophoresis and IR spectra. Attributed to the strong steric-hindrance effect of pectin, the fluorescence intensity and surface hydrophobicity of the soy protein isolate were significantly decreased after Maillard reaction. However, both solubility and emulsifying properties of the conjugates were significantly improved. Results indicated that both pectin samples played favorable roles in protein modification.

Structural characterization and rheological properties of a pectin with anti-constipation activity from the roots of Arctium lappa L

A new pectin (ALP-2) was extracted from the roots of Arctium lappa L. with the molecular weight of 1.84 × 10⁶ Da. ALP-2 was composed of rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose and arabinose. Results of NMR revealed that the dominant linkage types of ALP-2 were →4-α-GalpA-6-OMe-(1→, →2-α-Rha-(1→, →5-α-Araf-(1→ and →3,6-β-Galp-(1→. The ELISA results indicated ALP-2 was a typical pectin with HG chain and RG-I chain. The rheological experiments showed that ALP-2 fluid exhibited shear thinning behavior. The viscosity of ALP-2 was mainly affected by concentration, temperature, and pH. The ALP-2 fluid with elastic properties at high frequencies could be used as a thickener in the food industry. Moreover, ALP-2 with the dosages of 200 mg/kg and 400 mg/kg exhibited strong anti-constipation activity in vivo. ALP-2 treated groups could improve small intestinal movement rate and increase the weight of feces significantly in constipation mice. Therefore, ALP-2 could be considered as the active component for functional food or therapeutic agent in constipation therapy.

Characterization and anti-inflammatory effects of sulfated polysaccharide from the red seaweed Gelidium pacificum Okamura

In the present study, crude polysaccharides were extracted from Gelidium pacificum Okamura, and further purified to obtain the sulfated polysaccharide with molecular weight of 28,807 Da. Its monosaccharide composition mainly consisted of xylose (7.1%), galactose (59.7%) and galacturonic acid (19.76%). And the sulfate ester content of the sulfated polysaccharide was estimated as 8.8%. Structure analysis showed that the sulfated polysaccharide comprised of 1,4-linked-α-D-Galp3S, 1,2-linked-α-D-Xylp and 1,3-linked-β-D-GalpA residues, respectively. Its anti-inflammatory effects were investigated in LPS-stimulated human monocytic (THP-1) cells. The sulfated polysaccharide at a concentration of 5 μg/mL fully protected the THP-1 cells against LPS-stimulated cytotoxicity. Furthermore, the addition of sulfated polysaccharide resulted in a significant reduction of NO production in LPS-treated cells, and this effect appeared to be dose-related. The sulfated polysaccharide (5 μg/mL) significantly suppressed the mRNA and protein expression of toll-like receptor-4 (TLR-4), myeloid differentiation factor (MyD88) and tumor necrosis factor receptor-associated factor-6 (TRAF-6) in LPS-stimulated THP-1 cells. These results showed the sulfated polysaccharide not only provided a good protection against LPS-induced cell toxicity, but also exerted an anti-inflammatory effect via the TLR4 signaling pathway.

Biological Activity and Pharmacological Application of Pectic Polysaccharides: A Review

Pectin is a polymer with a core of alternating α-1,4-linked d-galacturonic acid and α-1,2-l-rhamnose units, as well as a variety of neutral sugars such as arabinose, galactose, and lesser amounts of other sugars. Currently, native pectins have been compared to modified ones due to the development of natural medicines and health products. In this review, the results of a study of the bioactivity of pectic polysaccharides, including its various pharmacological applications, such as its immunoregulatory, anti-inflammatory, hypoglycemic, antibacterial, antioxidant and antitumor activities, have been summarized. The potential of pectins to contribute to the enhancement of drug delivery systems has been observed.

Silver nanoparticles in situ synthesized by polysaccharides from Sanghuangporus sanghuang and composites with chitosan to prepare scaffolds for the regeneration of infected full-thickness skin defects

In recent years, silver nanoparticles have widely been used in antibacterial dressings to solve antibiotic resistance problems. However, traditional methods for reducing silver nanoparticles are usually toxic. To overcome this problem, Sanghuangporus sanghuang polysaccharides (FSHPs) were used as a green reducing agent to prepare silver nanoparticles (AgNPs) with a size of 3-35 nm. The FSHPs‑silver nanoparticles (FSHPs-Ag) composite with chitosan solution were then freeze-dried to obtain a porous sponge dressing of chitosan-FSHPs-Ag (CS-FSHPs-Ag). The internal pores of CS-FSHPs-Ag were between 50 and 100 μm and had good swelling and water retention properties, which could provide a moist environment for wounds. Based on the experimental results, the appropriate concentration of AgNPs required for CS-FSHPs-Ag to inhibit Escherichia coli and Staphylococcus aureus was determined. Moreover, there was no statistically significant difference between the material treatment and the blank control group, indicating that the material almost showed no toxicity to L929 cells. Finally, this material was used for dressing animal wounds. The results showed that the CS-FSHPs-Ag promoted wound contraction and internal tissue growth better than the wounds treated with Aquacel® Ag, which indicated that the CS-FSHPs-Ag has a great potential as an ideal wound dressing material.

Composition characterization, antioxidant capacities and anti-proliferative effects of the polysaccharides isolated from Trametes lactinea (Berk.) Pat

This study was designed to investigate the chemical characterization and bioactivity of the Trametes lactinea (Berk.) Pat polysaccharides (TLP). The crude TLP was fractionated into two fractions, namely TLP-1 and TLP-2 with Cellulose DEAE-52 and Sephadex G-150. HPLC and FT-IR analysis showed that TLP-1 and TLP-2 were heteropolysaccharides mainly composed of glucose with the average molecular weights of 443.19kDa and 388.83kDa, respectively. TLP-1 from water elution possessed of higher reducing power and scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide radical and hydroxyl radical than TLP-2 eluted by 0.1M of NaCl. In comparison with TLP-2, TLP-1 showed stronger growth inhibition against human hepatoblastoma HepG-2 cells and caused higher LDH leakage. However, TLP-1 showed lower growth inhibition against normal hepatocyte L-02 cells and lower LDH leakage than TLP-2. Flow cytometric analysis showed that TLP-1 had a stimulatory effect on apoptosis of HepG-2 cells. These findings suggested that the polysaccharides, especially TLP-1 could contribute to the potential anticancer effects of T. lactinea (Berk.) Pat, which might be valuable as a natural antioxidant source applied in both healthy medicine and food industry for health benefits.

Anti-cancer activity of di- and tri-organotin(IV) compounds with D-(+)-Galacturonic acid on human tumor cells

We have compared the anti-proliferative activity in vitro, of R₂SnGala (1-3) [R = Me, n-Bu, Ph] and novel R₃SnGala (4, 5) [R = Me, n-Bu] with D-(+)-Galacturonic acid [HGala; Gala^q-, q = (2) and (1) for R₂SnGala and R₃SnGala, respectively] compounds, towards human tumor cell lines of intestinal carcinoma (HCT-116) and breast adenocarcinoma (MCF-7). The new synthesized 4 and 5 compounds were characterized, in solution, by ¹H, ¹³C and ¹¹⁹Sn NMR, that showed that HGala acts as monoanionic moiety and evidenced the dynamic behavior of the compounds, due to inter-conversions involving the anomeric carbon atom of the ligand. Cell viability, apoptosis induction and cell cycle distribution were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay and flow cytometry, respectively. The cytotoxicity of the compounds, in the micro-submicromolar range, changed in the order of the organotin(IV) moieties, according to 5 > 3 > 2, while 1 and 4, containing Me_nSn(IV) (n = 2,3) moieties, were ineffective. Compound 5 showed peculiar cytotoxic effects. It did not cause time dependent inhibition of cell growth nor accumulated into the cells. Cell death induced by the active 2, 3, and 5, was shown to be apoptotic by measuring the exposure of phosphatidylserine to the outer membrane and the loss of mitochondrial potential. All the cytotoxic compounds induced an accumulation of cells in the subG0/G1phase, while only 2 and 3 perturbed the cell cycle confining viable cells in G0/G1phase. Finally, none of the compounds investigated affected the viability of normal intestinal or liver cells, indicating selectivity towards tumor cells.