Purification and analysis of the composition and antioxidant activity of polysaccharides from Helicteres angustifolia L

Polysaccharides in fruits: Biological activities, structures, and structure-activity relationships and influencing factors-A review

Fruits are a rich source of polysaccharides, and an increasing number of studies have shown that polysaccharides from fruits have a wide range of biological functions. Here, we thoroughly review recent advances in the study of the bioactivities, structures, and structure-activity relationships of fruit polysaccharides, especially highlighting the structure-activity influencing factors such as extraction methods and chemical modifications. Different extraction methods cause differences in the primary structures of polysaccharides, which in turn lead to different polysaccharide biological activities. Differences in the degree of modification, molecular weight, substitution position, and chain conformation caused by chemical modification can all affect the biological activities of fruit polysaccharides. Furthermore, we summarize the applications of fruit polysaccharides in the fields of pharmacy and medicine, foods, cosmetics, and materials. The challenges and perspectives for fruit polysaccharide research are also discussed.

Characterization and Antioxidant Activity of the Polysaccharide Hydrolysate from Lactobacillus plantarum LPC-1 and Their Effect on Spinach (Spinach oleracea L.) Growth

This study presents a comparison between two hydrolysis systems (MnO2/H2O2 and ascorbic acid (VC)/H2O2) for the depolymerization of exopolysaccharide (EPS) from Lactobacillus plantarum LPC-1. Response surface methodology (RSM) was used to optimize these two degradation systems, resulting in two H2O2-free degradation products, MEPS (MnO2/H2O2-treated EPS) and VEPS (VC/H2O2-treated EPS), where H2O2 residues in the final products and their antioxidant activity were considered vital points. The relationship between the structural variations of two degraded polysaccharides and their antioxidant activity was characterized. Physicochemical tests showed that H2O2 had a notable impact on determining the total and reducing sugars in the polysaccharides, and both degradation systems efficiently eliminated this effect. After optimization, the average molecular weight of EPS was reduced from 265.75 kDa to 135.41 kDa (MEPS) and 113.11 kDa (VEPS), improving its antioxidant properties. Characterization results showed that the two hydrolysis products had similar major functional groups and monosaccharide composition as EPS. The crystal structure, main chain length, and branched chain number were crucial factors affecting the biological activity of polysaccharides. In pot testing, two degraded polysaccharides improved spinach quality more than EPS due to their lower molecular weights, suggesting the advantages of low-molecular-weight polysaccharides. In summary, these two degradation techniques offer valuable insights for further expanding the utilization of microbial resources.

Microwave-assisted enzymatic extraction brings a notably high yield of polysaccharides from mountain Zizania latifolia

Mountain Zizania latifolia is produced at scale in China, and the edible swollen culm is exported to many countries, but little attention has been paid to its functional components. In this work, microwave-assisted enzymatic extraction (MAEE) is used for the first time to extract polysaccharides from mountain Z. latifolia swollen culm (PMZL). MAEE conditions optimized by Box-Behnken design-response surface methodology were as follows: 2.4% cellulase, microwaving for 6.0 min at 607 W, with a liquid-to-solid ratio of 63:1 ml g^-1 . Under these conditions, a notably high yield of 60.43% ± 1.12% for PMZL was achieved, which was significantly higher (p < 0.01) than from plain-grown varieties. PMZL are naturally occurring sulfated polysaccharide-protein complexes containing 8.46% ± 0.18% proteins and 7.86% ± 0.73% sulfates. PMZL comprises mannose, glucosamine, rhamnose, glucose, galactose, and arabinose at molar ratios of 3.80:2.68:1.00:17.41:5.12:2.91, with a weight-average molecular weight of 1569,219 Da and a number-average molecular weight of 364,088 Da. The surface morphology of PMZL is composed of tightly packed oval particles, and this kind of promising polysaccharides preferentially scavenges reactive nitrogen species. PRACTICAL APPLICATION: Due to global warming, the land available for planting vegetables is likely to expand to higher areas, so greater attention should now be paid to mountain-grown vegetables. This study provides an efficient way to obtain novel polysaccharides from mountain Zizania latifolia using microwave-assisted enzymatic extraction with a remarkably high yield of 60.4%. This promising source of natural carbohydrates has potential uses in pharmaceutical, nutraceutical, functional foods, cosmetics, and functional materials industries.

Microwave-Assisted Enzymatic Extraction, Partial Characterization, and Antioxidant Potential of Polysaccharides from Sagittaria trifolia Tuber

Sagittaria trifolia tuber is an aquatic vegetable. In this work, microwave-assisted enzymatic extraction (MEE) was used to extract S. trifolia tuber polysaccharides (STTPs). Optimum conditions were complex enzyme of 2 %, liquid-to-solid ratio of 43 : 1 mL g^-1 , microwave power of 506 W, and time of 8 min, under which STTPs yield was 36.22±0.69 %, higher than those of other methods. STTPs were sulfated polysaccharides with sulfur valence of S⁶⁺ . STTPs comprised mannose, glucose, galactose, and arabinose at a mole ratio of 3.69 : 19.33 : 6.21 : 1.00, molecular weights of 3606 kDa and 149.6 kDa, particle size of 220 nm, and zeta potential of -5.02 mV. The surface of STTPs was full of bumps and holes, and abundant in O1s and non-functionalized C1s. STTPs would scavenge reactive oxygen species with advantage. It would provide an efficient MEE method to obtain antioxidant STTPs, also a clue for extracting polysaccharides from starch-rich crops.

Onion and garlic polysaccharides: A review on extraction, characterization, bioactivity, and modifications

Allium cepa (onion) and Allium sativum (garlic) are important members of the Amaryllidaceae (Alliaceae) family and are being used both as food and medicine for centuries in different parts of the world. Polysaccharides have been extracted from different parts of onion and garlic such as bulb, straw and cell wall. The current literature portrays several studies on the extraction of polysaccharides from onion and garlic, their modification and determination of their structural (molecular weight, monosaccharide unit and their arrangement, type and position of glycosidic bond or linkage, degree of polymerization, chain conformation) and functional properties (emulsifying property, moisture retention, hygroscopicity, thermal stability, foaming ability, fat-binding capacity). In this line, this review, summarizes the various extraction techniques used for polysaccharides from onion and garlic, involving methods like solvent extraction method. Furthermore, the antioxidant, antitumor, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, and antidiabetic properties of onion and garlic polysaccharides as reported in in vivo and in vitro studies is also critically assessed in this review. Different studies have proved onion and garlic polysaccharides as potential antioxidant and immunomodulatory agent. Studies have implemented to improve the functionality of onion and garlic polysaccharides through various modification approaches. Further studies are warranted for utilizing onion and garlic polysaccharides in the food, nutraceutical, pharmaceutical and cosmetic industries.

In Vitro Hepatoprotective and Human Gut Microbiota Modulation of Polysaccharide-Peptides in Pleurotus citrinopileatus

Pleurotus citrinopileatus, a golden oyster mushroom, is popular in Asia and has pharmacological functions. However, the effects of polysaccharide-peptides extracted from Pleurotus citrinopileatus and underlying mechanism on digestive systme have not yet been clarified. Here, we determined the composition of two polysaccharide-peptides (PSI and PSII) from P. citrinopileatus and investigated the protective effects of on hepatoprotective and gut microbiota. The results showed that PSI and PSII were made up of similar monosaccharide moieties, except for the varying ratios. Furthermore, PSI and PSII showed that they have the hepatoprotective effects and significantly increased the viabilities and cellular total superoxide dismutase activities increased significantly in HepG2 cells. Intracellular triglyceride content and extracellular alanine aminotransferase and aspartate transaminase contents markedly decreased following treatment with 40 and 50 μg/mL PSI and PSII, respectively. Moreover, PSI and PSII activated the adiponectin pathway and reduced lipid accumulation in liver cells. PSI and PSII elevated short-chain fatty acid concentrations, especially butyric and acetic acids. 16S rRNA gene sequencing analysis showed that PSI promoted the relative abundances of Bifidobacteria, Lactobacillus, Faecalibacterium, as well as Prevotella generas in the gut. PSII markedly suppressed the relative abundances of Escherichia-Shigella and Bacteroides generas. We speculate that the PSI and PSII play a role through liver-gut axis system. Polysaccharide-peptides metabolize by gut microbiota to produce short-chain fatty acids (SCFAs) and in turn influence liver functions.

Optimisation of enzyme-assisted extraction of Erythronium sibiricum bulb polysaccharide and its effects on immunomodulation

In this study, polysaccharides of Erythronium sibiricum bulb were extracted using enzyme-assisted extraction technology and then optimised by response surface methodology. The characteristics and immunomodulatory activities of the polysaccharide (E1P) were investigated. Setting the yield of polysaccharides as the index, the effects of amylase content, zymolytic time, extraction pH and zymolytic temperature were investigated. The optimal extraction conditions for polysaccharides were as follows: amylase content, 1% weight of pre-treated powder; zymolytic time, 2 h; extraction pH, 7.5; and zymolytic temperature, 55 °C. The yield was predicted to be 61.10%, which agreed with the value obtained in confirmatory experiments (59.71% ± 2.72%). Further research indicated that the primary component of E1P is glucose; however, it also contains a small quantity of galactose and arabinose. In vitro assays showed that E1P and ESBP (another kind of E. sibiricum bulb polysaccharide extracted by water decoction in our previous study) could significantly promote the cellular viability and phagocytosis of RAW264.7 cells without cytotoxicity. Moreover, they could enhance the ability to secrete nitric oxide and cytokines such as TNF-α and IL-1β. However, the immunomodulatory activities of E1P were better than those of ESBP. According to the results of this study, enzyme-assisted extraction represents a new strategy for extracting E. sibiricum bulb polysaccharides with higher yield and better immune activity.

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.

Burdock Fructooligosaccharide Attenuates High Glucose-Induced Apoptosis and Oxidative Stress Injury in Renal Tubular Epithelial Cells

Hyperglycemia-induced apoptosis and oxidative stress injury are thought to play important roles in the pathogenesis of diabetic nephropathy (DN). Attenuating high glucose (HG)-induced renal tubular epithelial cell injury has become a potential approach to ameliorate DN. In recent years, burdock fructooligosaccharide (BFO), a water-soluble inulin-type fructooligosaccharide extracted from burdock root, has been shown to have a wide range of pharmacological activities, including antiviral, anti-inflammatory, and hypolipidemic activities. However, the role and mechanism of BFO in rat renal tubular epithelial cells (NRK-52E cells) have rarely been investigated. The present study investigated the protective effect of BFO on HG-induced damage in NRK-52E cells. BFO could protect NRK-52E cells against the reduced cell viability and significantly increased apoptosis rate induced by HG. These anti-oxidative stress effects of BFO were related to the significant inhibition of the production of reactive oxygen species, stabilization of mitochondrial membrane potential, and increased antioxidant (superoxide dismutase and catalase) activities. Furthermore, BFO increased the expression of Nrf2, HO-1, and Bcl-2 and decreased the expression of Bax. In conclusion, these findings suggest that BFO protects NRK-52E cells against HG-induced damage by inhibiting apoptosis and oxidative stress through the Nrf2/HO-1 signaling pathway.

Sequential Extraction, Characterization, and Analysis of Pumpkin Polysaccharides for Their Hypoglycemic Activities and Effects on Gut Microbiota in Mice

This study aimed to extract polysaccharides from pumpkin, characterize the structures of four of them, and evaluate their in vitro antioxidant and hypoglycemic activities. Additionally, an animal model of type 2 diabetes mellitus (T2DM) was established and used to determine their hypoglycemic and hypolipidemic effects in vivo, and the underlying mechanisms related to the regulation of gut microbiota. Water-extracted crude pumpkin polysaccharides (W-CPPs), water extraction and alcohol precipitation crude pumpkin polysaccharides (WA-CPPs), deproteinized pumpkin polysaccharides (DPPs), and refined pumpkin polysaccharides (RPPs) were sequentially extracted and purified from pumpkin powder by hot water extraction, water extraction, and alcohol precipitation, deproteinization and DEAE-52 cellulose gel column, respectively. The extraction and purification methods had significant influence on the extraction yield, physicochemical properties, and in vitro antioxidant and hypoglycemic activities. W-CCP and RPPs had a significant positive free radical-scavenging capacities and inhibitory activities on α-glucosidase and α-amylase. RPP-3 not only inhibited the uptake of glucose in Caco-2 monolayer but also promoted the excretion of glucose, while RPP-2 had no inhibitory effect. Animal experiment results showed that W-CPP treatment significantly improved the T2DM symptoms in mice, which included lowering of fasting blood glucose (FBG), reducing insulin resistance (IR), and lowering of blood lipid levels. It increased the diversity of intestinal flora and reduced the harmful flora of model mice, which included Clostridium, Thermoanaerobe, Symbiotic bacteria, Deinococcus, Vibrio haematococcus, Proteus gamma, and Corio. At the family level, W-CPP (1,200 mg/kg) treatment significantly reduced the abundance of Erysipelotrichaceae, and the Akkermanaceae of Verrucobacterium became a biomarker. Pumpkin polysaccharides reshaped the intestinal flora by reducing Erysipelotrichaceae and increasing Akkermansia abundance, thereby improving blood glucose and lipid metabolism in the T2DM mice. Our results suggest that W-CCP and RPP-3 possess strong antioxidant and hypoglycemic activities, and are potential candidates for food additives or natural medicines.

Plants arabinogalactans: From structures to physico-chemical and biological properties

Arabinogalactans (AGs) are plant heteropolysaccharides with complex structures occasionally attached to proteins (AGPs). AGs in cell matrix of different parts of plant are freely available or chemically bound to pectin rhamnogalactan. Type I with predominantly β-d-(1 → 4)-galactan and type II with β-d-(1 → 3) and/or (1 → 6)-galactan structural backbones construct the two main groups of AGs. In the current review, the chemical structure of AGs is firstly discussed focusing on non-traditional plant sources and not including well known industrial gums. After that, processes for their extraction and purification are considered and finally their techno-functional and biological properties are highlighted. The role of AG structure and function on health advantages such as anti-tumor, antioxidant, anti-ulcer- anti-diabetic and other activites and also the immunomodulatory effects on in-vivo model systems are overviewed.

Characterization and Evaluation of the Pro-Coagulant and Immunomodulatory Activities of Polysaccharides from Bletilla striata

Bletilla striata is widely used for stanching bleeding. In this study, polysaccharides from B. striata (BSP) were extracted by hot water. Four polysaccharides named BSP-1-BSP-4 were fractionated using DEAE-52 cellulose. BSP fractions contained sulfate, and the degrees of substitution of BSP-3 and BSP-4 were 1.59 and 1.70, respectively. Analysis of monosaccharide composition showed that four polysaccharides were mainly composed of mannan and glucose. The in vitro results showed that BSP-1-BSP-4 elicited pro-coagulant capacities by shortening the activating partial thromboplastin time, prothrombin time, and thrombin time and elevating the fibrinogen content. Immunomodulatory activity was evaluated by MTT assay, the pinocytic capacity and NO production. Although BSP fractions did not affect RAW 264.7 cell viability, they, especially BSP-2, enhanced the immunomodulatory activity by increasing the pinocytic capacity and NO production. Overall, BSP may be developed as a potential coagulant with immunomodulatory effects.

Preparation, characterization, antioxidant and antiglycation activities of selenized polysaccharides from blackcurrant

An ultrasound-assisted enzymatic method was used to extract the polysaccharides from blackcurrant fruits (BP), and then a nitric acid-sodium selenite method was employed to prepare twelve kinds of selenized blackcurrant polysaccharides (SBPs). Among them, SBP-1, SBP-2 and SBP-3 with different selenium contents of 250 ± 11, 312 ± 15 and 643 ± 24 μg g⁻¹, displayed relatively higher 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) scavenging activities than the others. After treating with a Sepharose-6B chromatography column, the purified blackcurrant polysaccharide (PBP) and three selenized polysaccharides (PSBP-1, PSBP-2, PSBP-3) with high purity were obtained. Compared with PBP, PSBPs possessed a larger absolute value of zeta potential (ZP) and smaller particle size, indicating the positive influence of selenized modification on physical stability of polysaccharides. Ultraviolet (UV), Fourier transform infrared (FT-IR) and circular dichroism (CD) spectra confirmed that selenium had been introduced onto the polysaccharide structure. X-ray diffraction (XRD) and I₂–KI reaction results indicated that selenized modification did not cause an obvious change in crystal form and branch structure of blackcurrant polysaccharides. In addition, PSBPs were superior to PBP in antioxidant and antiglycation capacities, and the bioactivities of PSBPs were significantly improved in positive correlation with selenium content. This study suggested that PSBPs may be a potential selenium source and serve as functional food and medicine.

An ultrasound-assisted enzymatic method was used to extract the polysaccharides from blackcurrant fruits (BP), and then a nitric acid-sodium selenite method was employed to prepare twelve kinds of selenized blackcurrant polysaccharides (SBPs).

First demonstration of protective effects of purified mushroom polysaccharide-peptides against fatty liver injury and the mechanisms involved

Fatty liver (FLD) disease is a consequence of metabolic syndrome, which is a health problem worldwide with a phenomenal rise in prevalence. In this study, two hepatoprotective polysaccharide-peptides were extracted from the mushroom Auricularia polytricha followed by chromatographic fractionation of the extract on the ion exchanger DEAE-cellulose and gel filtration on Sephadex-200 to yield two purified fractions: APPI and APPII. The monosaccharide compositions, FT-IR, N-terminal sequences, internal peptide sequences and molecular weights of the two fractions were determined. Furthermore, their hepatoprotective effect on human hepatoma HepG2 cells in vitro and in an animal model of fatty liver disease was evidenced by the findings that APPI and APPII diminished lipid deposit in cells, blood and the liver, increased cellular antioxidant activity and viability, and protected the liver against injury. The mechanistic study revealed that APPI and APPII activated the adiponectin pathway, up-regulated expression of genes controlling free fatty acid (FFA) oxidation, such as AMPK, CPTl, ACOX1 and PPARα genes, enhanced lipid metabolism, preserved hepatic function, promoted the antioxidant defense system and reduced lipid peroxidation. Hence the bioactive compounds of A. polytricha could serve as therapeutic agents in the food and pharmaceutical industries.

Microwave-Assisted Extraction, Purification, Partial Characterization, and Bioactivity of Polysaccharides from Panax ginseng

Polysaccharides are a main active substance in Panax ginseng; however, microwave-assisted extraction used to prepare P. ginseng polysaccharides (MPPG) has rarely been reported, and knowledge of the bactericidal activity of P. ginseng polysaccharides remains low. Thus, this study was designed to investigate the extraction of P. ginseng polysaccharides by using two methods-hot water extraction and microwave-assisted extraction-and compare their chemical composition and structure. In addition, their antibacterial and antioxidant activities were also determined. The data implied that P. ginseng polysaccharides extracted by microwave-assisted extraction possessed a higher extraction yield than hot water extraction (WPPG) under optimized conditions, and the actual yields were 41.6% ± 0.09% and 28.5% ± 1.62%, respectively. Moreover, the preliminary characterization of polysaccharides was identified after purification. The WPPG with the molecular weight (Mw) of 2.07 × 105 Da was composed of Man, Rib, Rha, GalA, Glu, Gal, and Arab, and the typical characteristics of polysaccharides were determined by IR spectra. Compared with WPPG, MPPG had a higher Mw, uronic acid content, and Glu content. More importantly, the antioxidant activity of MPPG was higher than WPPG, which was probably ascribed to its highly Mw and abundant uronic acid content. Besides, both of them exhibited high bactericidal activity. These results demonstrate that microwave-assisted extraction is an effective method for obtaining P. ginseng polysaccharides, and MPPG could be applied as an antioxidant and antibacterial agent.

Optimization extraction, characterization and anticancer activities of polysaccharides from mango pomace

Response surface methodology was used to optimize the extraction conditions for ultrasonic-assisted extraction of polysaccharides from mango pomace. The Optimum extraction conditions consisted of extraction temperature of 74 °C, ultrasonic power of 170 W, extraction time of 100 min, and raw material-to-water ratio of 1:40 g/mL. Under these conditions, the extraction yield was 3.71 ± 0.07%. Three novel polysaccharide fractions, MG-1, MG-2 and MG-3 were purified from the crude polysaccharides by using DEAE-52 cellulose and Sephadex G-100 column chromatography. The molecular weight and monosaccharide composition of polysaccharide fractions (MPFs) were analyzed by high performance liquid gel permeation chromatography (HPGPC) and HPLC analysis, respectively. The characterizations of MPFs were conducted with FT-IR, ¹H NMR and SEM. Furthermore, the anticancer activities of the polysaccharide fractions were also investigated in vitro. Results showed that MG-1, MG-2 and MG-3 exhibited significant anticancer activities against HepG2, MCF-7, A549, HeLa, A2780, HCT-116 and BGC-823 cells in a dose-dependent manner. MPFs were also showed to promote apoptosis as seen in the nuclear morphological examination study using calcein acetyl methoxy methyl easter (calcein-AM) and propidium iodide (PI) staining. This research could serve as a theoretical reference for the efficient utilization of MPFs in biomedical and functional food.

Characterization of polysaccharides and their antioxidant properties from Plumula nelumbinis

Two novel polysaccharides, Plumula nelumbinis (P. nelumbinis) polysaccharide I (LNP I) and P. nelumbinis polysaccharide II (LNP II), were extracted and purified from P. nelumbinis, and a sulfated polysaccharide, P. nelumbinis polysaccharide III (LNP III), with a substitution degree of 0.62 was prepared from LNPI. The structures of the LNPs were preliminarily characterized using high performance size exclusion chromatography (HPSEC), gas chromatography-mass spectrometry (GC–MS), Fourier transformed infrared spectrometry (FT-IR), and nuclear magnetic resonance (NMR) spectrometry. In addition, evaluation of the antioxidant activity of the LNPs showed that they could significantly increase the proliferation of RAW264.7 macrophages (P < 0.05) and improve the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) based on cell model of H₂O_2-induced oxidative damage. This suggested that these LNPs may be used as potential antioxidants.