Low Molecular Weight Polysaccharides Research Articles

Glycoside Phosphorylase Catalyzed Cellulose and β-1,3-Glucan Synthesis Using Chromophoric Glycosyl Acceptors.

Glycoside phosphorylases are enzymes that are frequently used for polysaccharide synthesis. Some of these enzymes have broad substrate specificity, enabling the synthesis of reducing-end-functionalized glucan chains. Here, we explore the potential of glycoside phosphorylases in synthesizing chromophore-conjugated polysaccharides using commercially available chromophoric model compounds as glycosyl acceptors. Specifically, we report cellulose and β-1,3-glucan synthesis using 2-nitrophenyl β-d-glucopyranoside, 4-nitrophenyl β-d-glucopyranoside, and 2-methoxy-4-(2-nitrovinyl)phenyl β-d-glucopyranoside with Clostridium thermocellum cellodextrin phosphorylase and Thermosipho africanus β-1,3-glucan phosphorylase as catalysts. We demonstrate activity for both enzymes with all assayed chromophoric acceptors and report the crystallization-driven precipitation and detailed structural characterization of the synthesized polysaccharides, i.e., their molar mass distributions and various structural parameters, such as morphology, fibril diameter, lamellar thickness, and crystal form. Our results provide insights for the studies of chromophore-conjugated low molecular weight polysaccharides, glycoside phosphorylases, and the hierarchical assembly of crystalline cellulose and β-1,3-glucan.

Effects of low molecular weight polysaccharide from Sargassum thunbergii against palmitic acid-induced intracellular lipid accumulation in 3T3-L1 adipocyte and HepG2 cells

Low molecular weight polysaccharides can be isolated from Sargassum thunbergii (LMPST) and in vitro experiments were conducted to evaluate the inhibitory effects on lipids. Two natures of LMPST were attained from S. thunbergii and appraised their LMPST on palmitic acid (PA) induced lipid accretion in HepG2, and 3T3-L1 cells. LMPST treatment lessened lipid deposition and intracellular free fatty acid and triglyceride intensities in PA-treated above mentioned cells. The mechanistic study publicized that LMPST2 significantly suppressed adipogenesis and stimulated the PA-treated 3T3-L1 cells occupied in the lipolysis pathway. Furthermore, in PA-treated HepG2 cells, the free fatty acid oxidation was significantly increased by LMPST2. Given these constructive properties of LMPST2 from S. thunbergii, is a potential candidate for diminishing the intracellular lipids, and for a therapeutic agent in those conditions.

Selenochemical modification of low molecular weight polysaccharides from Grifola frondosa and the mechanism of their inhibitory effects on gastric cancer cells

An important micronutrient involved in immune response and antitumor is selenium. LMW-GFP, a polysaccharide extracted from Grifola frondosa seed bodies, has a relatively weak antitumor effect on BGC-823 and MFC cells in vitro, whereas selenium binding to LMW-GFP can significantly increase the in vitro antitumor activity of LMW-GFP. In this study, Se-LMW-GFP was prepared by the HNO3-Na2SeO3 method, and the structures of LMW-GFP and Se-LMW-GFP were characterized by UV–visible spectroscopy of absorption, FTIR spectroscopy, and electron scanning microscopy, and these structural analyses showed that selenium was successfully complexed to LMW-GFP. The selenium content of Se-LMW-GFP was measured to be 2.08 % ± 0.08 % by ICP-MS. The anti-tumor activity of LMW-GFP before and after selenium modification was compared by cellular experiments, and the findings indicated that the anti-tumor activity of Se-LMW-GFP was considerably improved over that of LMW-GFP, and inhibited the proliferation of BGC-823 cells and MFC cells through a combination of the Fas/FasL-mediated exogenous death receptor pathway as well as the endogenous mitochondrial pathway. Our results suggest that Se-LMW-GFP not only has great potential for natural health food and anti-gastric cancer drug development but is also a good selenium supplement.

Foliar Application of Micronutrients and Low Molecular Weight Polysaccharides on White Radish Grown in Impoverished Soil

Foliar application has been considered as the most effective way to supplement nutrients for crops. Besides macro- and micro-nutrients, foliar fertilizers should contain surfactants to wet plant leaves, and other adjuvants to control spray and prolong the retention time of nutrients on the leaf surface. Having diverse structures and properties, some polysaccharides can not only be used as drift control or adhesion agents to improve performance on the leaf and reduce washout of agrochemicals by rainwater, but also be utilized as plant growth promoters (PGP) or immuno-stimulating agents in agricultural production. In this study, low molecular weight chitosan and xanthan obtained by radiation degradation have been added to the microelement fertilizers to control diseases, promote the growth and development of vegetables, and further increase their nutrient uptake. Field trials on white radishes grown on impoverished soil revealed that the resulting foliar fertilizers significantly reduced the infection of popular pests and diseases, remarkably promoted the growth and development of the radish plants. The yield attributes and marketable yield of radish from all treatments were much higher than those of the control. The highest yields were 61.99 and 64.94 tons per ha in season 2019 and 2020, respectively, in the plants treated with the fertilizer containing both chitosan and xanthan. These results suggest that the fertilizer composed of micronutrients and low molecular weight chitosan and xanthan could be applied for better vegetable crops.

Characterization of the Antiproliferative Activity of Sargassum muticum Low and High Molecular Weight Polysaccharide Fractions.

The extract obtained by pressurized hot water extraction from Sargassum muticum, to recover the bioactive compound known as fucoidan, was fractionated using membranes of 100, 50, 30, 10, and 5 kDa, obtaining five retentates and the final permeate. These fractions were characterized for phloroglucinol content, protein content, sulfate content, and trolox equivalent antioxidant capacity (TEAC); apart from oligosaccharides, FTIR and molar mass distribution were also evaluated. Retentates of 100 and 50 kDa showed higher values for phloroglucinol, TEAC, and sulfate content. The rheology of the alginate fraction was also evaluated. Regarding the potential antitumoral activity, all fractions were assessed in MCF-7 cells using a metabolic activity assay based on the reduction of a tetrazolium compound, the most efficient being R100 and R50. Based on the results, these fractions were compared with commercial fucoidans at the same concentrations, and similar results were found. In addition, synergistic cytotoxic effects using two drugs commonly used in breast cancer, cis-Platinum (cis-Pt) and 5-fluorouracil (5-FU), were tested in combination with R100 and R50. Promising results were obtained when the retentate and the drugs were mixed, showing an improvement in the cytotoxicity induced by the chemotherapy.

The Potential Hypoglycemic Competence of Low Molecular Weight Polysaccharides Obtained from Laminaria japonica.

This study aimed to assess the hypoglycemic efficacy of low molecular weight polysaccharides fractions obtained from Laminaria japonica (LJOO) in a model of type 2 diabetes mellitus (T2DM) constructed using mice. Biochemical parameters were measured after 4 weeks of continuous gavage, and fasting blood glucose (FBG) concentrations were analyzed. Pathological changes in tissues were assessed. The intestinal contents were obtained for 16S rDNA high-throughput sequencing analysis and detection of short-chain fatty acids (SCFAs). LJOO lowered FBG and insulin concentrations. It altered the gut microbiota composition, as evidenced by enriched probiotic bacteria, along with an increase in the Bacteroidetes/Firmicutes ratio and a decrease in the population of harmful bacteria. LJOO stimulated the growth of SCFA-producing bacteria, thereby increasing cecal SCFAs levels. LJOO can potentially aid in alleviating T2DM and related gut microbiota dysbiosis. LJOO may be used as a food supplement for patients with T2DM.

Role of some structural features in EPS from microalgae stimulating collagen production by human dermal fibroblasts

ABSTRACTExopolysaccharides (EPS) from the microalgae Porphyridium cruentum, Chrysotila dentata, Pavlova sp., Diacronema sp., Glossomastix sp., Phaeodactylum tricornutum, and Synechococcus sp. were isolated and depolymerized. First, EPS were submitted to a high pressure pre-treatment step, followed by a solid acid-catalyzed hydrolysis step carried out in a batch or recycle fixed-bed reactor, using a strong acidic cation-exchange resin. Twenty-eight different EPS forms were thus obtained. After characterization of their main structural features (weight- and number-averaged molecular weight, polydispersity index, sulfate and uronic acid contents), we investigated the structure–function relationship of their pro-collagen activity. We found that native microalgae EPS were able to inhibit until 27% of human matrix metalloproteinase-1 (MMP-1) activity while the depolymerized forms were able to enhance collagen production by two different human fibroblast lines, used as cell models due to their major role in dermal collagen biosynthesis. The most active EPS forms, obtained by depolymerization in the recycle fixed-bed reactor of D. ennorea and Glossomastix sp. EPS, led to 390% increase in collagen production. Finally, principal component (PCA) and Pearson analyses indicated that MMP-1 inhibition was strongly correlated to the sulfate group content of EPS whereas collagen production by fibroblasts was mostly related to their proportion of low molecular weight polysaccharides (<10 kDa). Uronic acid content of EPS was also shown essential but only if the size of EPS was reduced in the first place. Altogether, these results gave new insights of the dermo-cosmetic potential of microalgae EPS as well as the key parameters of their activity.

Preparation of low molecular weight polysaccharides from Tremella fuciformis by ultrasonic-assisted H2O2-Vc method: Structural characteristics, in vivo antioxidant activity and stress resistance

Different methods were used to degrade Tremella fuciformis polysaccharides (TFP) and prepare low molecular weight polysaccharides of Tremella fuciformis (TFLP) to improve their bioavailability. It was found that the TFLP prepared by ultrasonic-assisted H2O2-Vc method showed the highest level of antioxidant activity and stress resistance in C. elegans. The structural characteristics, in vivo antioxidant and stress resistance of TFLP-1 were evaluated after isolation and purification of TFLP, it was found that TFLP-1 was an acid polysaccharide with a molecular weight of 75770 Da, which mainly composed of mannose. Meanwhile, it could regulate the antioxidant activity and stress resistance in C. elegans by upregulating the transcription of fat-5, fat-7, acs-2, glp-1, hsf-1, hsp-1, mtl-1, nhr-49, skn-1 and sod-3 mRNA. The improvement effects were closely related to the significant regulation of galactose metabolism, alpha linolenic acid metabolism, and pantothenate and CoA biosynthesis metabolic pathways. These results provided insights into the high value application of Tremella fuciformis in the food industry and the development of antioxidant related functional foods.

Potential use of grape and wine polysaccharide extracts as fining agents to modulate the volatile composition of Viura wines

This paper describes for the first time the use of grape derived polysaccharide extracts as potential fining agents to modulate the volatile composition of Viura white wines. Polysaccharide extracts were obtained from white grape pomace, red wine pomace, white must, red must, white wine, and lees from white wine.Except for higher alcohols, the extracts from white pomace, red pomace and white lees increased the content of most volatile compounds after one and twelve months of bottle aging. They could be used to enhance fruity and floral aromas and reduce unpleasant aromas, showing as good modulators of white wine aroma. The presence of mannoproteins, glucans, non-pectic polysaccharides, and low molecular weight polysaccharides increased the content of most volatile families. Polysaccharides of medium molecular weight showed negative correlations with volatile contents. Our results support the use of winemaking by-products to obtain valuable polysaccharides, contributing to the circular economy.

Structural characterization of Hericium erinaceus polysaccharides and the mechanism of anti-T2DM by modulating the gut microbiota and metabolites

A low molecular weight polysaccharides of HEP-1, with molecular weights of 1.67 × 104 Da and composition of →6)-β-D-Glcp-(1→, →3)-β-D-Glcp-(1→, β-D-Glcp-(1→ and →3,6)-β-D-Glcp-(1→, was isolated and characterized from the fruiting body of Hericium erinaceus. The results indicated that HEP-1 showed potential effects against T2DM-induced imbalance of glucose and lipid metabolism by promoting the serum glucose uptake by hepatic glycogen synthesis via activating the IRS/PI3K/AKT signaling pathway, and inhibiting fatty acid synthesis and reducing hepatic lipid accumulation via activating the AMPK/SREBP-1c signaling pathways. Besides, HEP-1 promoted the production of beneficial bacteria in the gut, and increased the beneficial metabolites in liver through the gut-liver axis, consequently, resisting the occurrence of T2DM.

Optimization and Physicochemical Characterization of Polysaccharide Purified from Sonneratia caseolaris Mangrove Leaves: a Potential Antioxidant and Antibiofilm Agent.

The Box-Behnken design was applied to determine the optimal parameters of the extraction condition by using the response surface methodology (RSM) from the leaves of Sonneratia caseolaris L. The result indicates the best-optimized conditions used for the extraction of polysaccharides at 84.02°C temperature, 3.12h time, and 27.31mL/g for the water-to-material ratio. The maximum experimental yield of 8.81 ± 0.09% was obtained which is in agreement with the predicted value of 8.79%. Thereafter, low molecular weight polysaccharide (SCLP) was separated after sequentially being purified through column chromatography with a relative molecular weight of 3.74kDa. The physicochemical properties were evaluated by characterization techniques such as FT-IR spectra, NMR spectrum, and SEM analysis. RP-HPLC analysis confirmed that SCLP was a heteropolysaccharide, majorly comprising rhamnose (28.25%), and xylose (27.17%) residues, followed by mannose (18.90%), and galactose (17.17%), respectively. Thermal analysis (TGA-DSC) results showed that SCLP is a highly thermostable polymer with a degradation temperature of 361.63°C. X-ray diffraction patterns and tertiary structure analyses indicate that SCLP had a semi-crystalline polymer having a triple-helical configuration. Moreover, SCLP displayed potential antibiofilm ability for all the tested pathogens while stronger activity against Klebsiella pneumoniae and Pseudomonas aeruginosa. In addition, SCLP has potential in vitro antioxidant activity on DPPH, ABTS radical, superoxide, and Fe2+ chelating. These findings indicate that the polysaccharide has potentially been used in functional food, cosmetics, and pharmacological industries.

Structural Characterization of an Alcohol-Soluble Polysaccharide from Bletilla striata and Antitumor Activities in Vivo and in Vitro.

In general, Bletilla striata polysaccharides were mostly water-soluble. However, the structural property, immunomodulatory effects and antitumor activities of alcohol-soluble Bletilla striata polysaccharide were rarely reported. In this study, an alcohol-soluble Bletilla striata polysaccharide was firstly extracted, investigated the structural property and evaluated the antitumor activity in vivo and in vitro. Results showed that BSAP was a low molecular weight polysaccharide (2.29×104 Da) and consisted of glucose, xylose and mannose (molar ratio: 2.39 : 1.00 : 0.21). Animal experiments results suggested that BSAP could effectively inhibit the expansion of H22 solid tumors, protect thymus and spleen, improve macrophages, lymphocytes and NK cells activities and enhance lymphocyte subsets proportion, presenting a better immunological enhancement effect in vivo. Additionally, the results of cell experiments showed that BSAP had obvious antitumor effect in vitro, including inhibiting the proliferation of H22 cells and inducing the apoptosis of tumor cells. These results would provide theoretical basis and new ideas for the further development and utilization of BSAP in the biomedical field.

Polysaccharide-Peptide from Trametes versicolor: The Potential Medicine for Colorectal Cancer Treatment.

The incidence and mortality of colorectal cancer have shown an upward trend in the past decade. Therefore, the prevention, diagnosis, and treatment of colorectal cancer still need our continuous attention. Finding compounds with strong anticancer activity and low toxicity is a good strategy for colorectal cancer (CRC) therapy. Trametes versicolor is a traditional Chinese medicinal mushroom with a long history of being used to regulate immunity and prevent cancer. Its extractions were demonstrated with strong cell growth inhibitory activity on human colorectal tumor cells, while the anticancer activity of them is not acted through a direct cytotoxic effect. However, the intricacy and high molecular weight make mechanistic research difficult, which restricts their further application as a medication in clinical cancer treatment. Recent research has discovered a small molecule polysaccharide peptide derived from Trametes versicolor that has a distinct structure after decades of Trametes versicolor investigation. Uncertain molecular weight and a complex composition are problems that have been solved through studies on its structure, and it was demonstrated to have strong anti-proliferation activity on colorectal cancer in vitro and in vivo via interaction with EGFR signaling pathway. It opens up new horizons for research in this field, and these low molecular weight polysaccharide peptides provide a new insight of regulation of colorectal cancer proliferation and have great potential as drugs in the treatment of colorectal cancer.

α-D-1,3-glucan from Radix Puerariae thomsonii improves NAFLD by regulating the intestinal flora and metabolites

Radix Puerariae thomsonii, the root of the botanical family Fabaceae species Pueraria montana var. thomsonii (Benth.) MR Almeida, can be used as food or medicine. Polysaccharides are important active constituents of this root. A low molecular weight polysaccharide, RPP-2 having α-D-1,3-glucan as the main chain, was isolated and purified. RPP-2 could promote the growth of probiotics in-vitro. Therefore, the effects of RPP-2 on a high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) C57/BL6J mouse models were investigated. RPP-2 could reduce HFD-induced liver injury by reducing inflammation, glucose metabolism, and steatosis, thereby improving NAFLD. RPP-2 regulated the abundances of intestinal floral genera Flintibacter, Butyricicoccus, and Oscillibacter, and their metabolites Lipopolysaccharide (LPS), bile acids, and short-chain fatty acids (SCFAs), thereby improving inflammation, lipid metabolism, and energy metabolism signaling pathways. These results confirmed that RPP-2 play a prebiotic role by regulating intestinal flora and microbial metabolites, playing a multi-pathway and multi-target role in improving NAFLD.

Analysis of the microscopic interactions between processed Polygonatum cyrtonema polysaccharides and water

The dissolution and microscopic interactions of processed Polygonatum cyrtonema polysaccharides in water are extremely important because they strongly influence the process to extract these polysaccharides from water. In this paper, molecular dynamics simulation methods were used to analyse the influence of extraction temperature, concentration and molecular weight on the radial distribution function (RDF), mean square displacement (MSD), diffusion coefficient (D), radius of gyration (Rg), and microstructure of processed Polygonatum cyrtonema polysaccharides in water as well as the intrinsic viscosity (η), hydrogen bond characteristics and microscopic interactions in the solutions. The research results showed that the extraction temperature, concentration and molecular weight of the polysaccharides had important effects on the RDF, MSD, D, Rg, η, hydrogen bond characteristics and the microstructure of the polysaccharide molecules, but there were some major differences. The order of the influence of the factors affecting the dissolution of polysaccharides in water was temperature > concentration > molecular weight. Extraction temperature, material fluid ratio and molecular weight had greater influence on the fluidity and dissolution state of the polysaccharides in water. As the solute concentration and molecular weight increased, hydrogen bonds between polysaccharides and water inhibited their dissolution and diffusion. Properly increasing the temperature, reducing the concentration and selecting low molecular weight polysaccharides enhanced the dissolution and diffusion of the polysaccharides in the solution system. Molecular weight was the main factor affecting the η of the polysaccharide solutions. These results can provide theoretical guidance for the extraction or tea brewing process of Polygonatum cyrtonema polysaccharides in future work.

Extraction, Structure and Immunoregulatory Activity of Low Molecular Weight Polysaccharide from Dendrobium officinale.

The ethanol precipitation method has been widely-used for Dendrobium officinale polysaccharides preparation. However, the alcohol-soluble fractions have always been ignored, which causes significant wastes of resources and energies. In this study, the extraction, physicochemical properties, and immune regulation activity of an edible D. officinale polysaccharide (DOPs) isolated from the supernatant after 75% ethanol precipitation were systematically investigated. The structural characteristics determination results showed that DOPs was mainly composed of glucose and mannose at a molar ratio of 1.00:5.78 with an average molecular weight of 4.56 × 103 Da, which was made up of α-(1,3)-Glcp as the main skeleton, and the α-(1,4)-Glcp and β-(1,4)-Manp as the branches. Subsequently, the cyclophosphamide (CTX)-induced immunosuppressive mice model was established, and the results demonstrated that DOPs could dose-dependently protect the immune organs against CTX damage, improve the immune cells activities, and promote the immune-related cytokines (IL-2, IFN-γ and TNF-α) secretions. Furthermore, DOPs treatment also effectively enhanced the antioxidant enzymes levels (SOD, GSH-Px) in sera and livers, therefore weakening the oxidative damage of CTX-treated mice. Considering these above data, DOPs presented great potential to be explored as a natural antioxidant and supplement for functional foods.

Enzymatic hydrolysate of porphyra enhances the intestinal mucosal functions in obese mice

Intestinal mucosal immunity is important to human body; however, obesity induced by high-fat diet may bring a series of problems, such as chronic inflammation which may damage intestinal mucosal immunity. In this study, the effects of two different enzymatic hydrolysates of porphyra on the function of intestinal mucosal were explored in obese mice. The results showed that 10 consecutive weeks of high-fat dietary intake resulted in weight gain and intestinal abnormalities in C57BL/6 mice. However, the administration of enzymatic hydrolysate of porphyra effectively protected the intestinal mucosa from these injuries while reducing levels of oxidative stress (MDA, GSH, and GSH-Px). Specifically, they were found to improve small intestine morphological structure, increase growth of goblet cells and mucous, raise expression levels of lysozyme, and stimulate SIgA secretion, especially in the group administered with the enzymatic hydrolysate containing protease and polysaccharide enzyme (EHPP). The results showed that the enzymatic hydrolysates of porphyra may provide a protective measure to maintain intestinal mucosal barriers, which is beneficial to overall health. Porphyra is widely distributed all over the world. Moreover, an increasing number of studies have described its diverse biological functions. Therefore, it is necessary to find a way to develop products related to porphyra. In this study, a new type of polysaccharide enzyme of porphyra found in our previous research was used to make a clear porphyra energy drink with a lower molecular weight polysaccharide. Our findings highlighted the repaired intestinal barriers in obese bodies after the treatment with the enzymatic hydrolysate. PRACTICAL APPLICATIONS: Porphyra is widely distributed all over the world. Moreover, an increasing number of studies have described its diverse biological functions. Therefore, it is necessary to find a way to develop products related to porphyra. In this study, a new type of polysaccharide enzyme of porphyra found in our previous research was used to make a clear porphyra energy drink with a lower molecular weight polysaccharide. Our findings highlighted the repaired intestinal barriers in obese bodies after the treatment with the enzymatic hydrolysate.

Structural characterization of a low molecular weight Bletilla striata polysaccharide and antitumor activity on H22 tumor-bearing mice.

In this study, a novel low molecular weight polysaccharide (named LMW-BSP) was extracted from Bletilla striata at 4°C. The results of structural characteristics analysis showed that LMW-BSP was a 23kDa neutral polysaccharide contained glucose and mannose at a molar ratio of 1.00:1.26. Structural investigations of the periodate oxidation studies, Smith-degradation as well as methylation were performed, and combined with 1D and 2D NMR spectroscopy, the main chain residues sequence of LMW-BSP was concluded to be: α-D-Manp-(1→3)-β-D-Manp-(1→[4)-β-D-Glcp-(1]2→4)-β-D-Manp-(1→3)-β-D-Manp-(1→. Moreover, the antitumor activity of LMW-BSP was evaluated in H22 tumor-bearing mice. And the results suggested that LMW-BSP could effectively improve immune cells activities and lymphocytes subsets proportions dose-dependently in tumor-bearing mice, leading to the apoptosis of H22 cells via G1 phase arrested. LMW-BSP inhibited tumor growth and exhibited antitumor effects in vivo. And it supported considering the novel polysaccharide as a potential drug component in hepatocellular carcinoma treatment.

Preparation, characterization, radical scavenging property and antidiabetic potential of laminarioligosaccharides derived from laminarin

Laminarin is a polysaccharide (dietary fibre), rich in marine brown seaweed. Derived low molecular weight polysaccharides exhibit various biofunctional properties including antitumor, anti-apoptotic, anti-inflammatory, antiobese and antioxidant activity. Hence, the present study aimed to hydrolyse laminarin using 0.2 M Hydrochloric acid (HCl) into laminarioligosaccharides and their characterization and evaluation of antioxidant, antidiabetic (α-amylase and α-glucosidase inhibition) properties in vitro. Thin layer chromatography (TLC) revealed the hydrolysis of laminarin up to 7 laminarioligosaccharides, also the hydrolysis pattern was validated by ultra-performance liquid chromatography (UPLC) and 1H and 13C NMR. Mass spectrometry investigation confirmed the molecular mass of laminarioligosaccharides. 1H and 13C NMR revealed that the laminarioligosaccharides has both β(1–6)-linked and β(1–3)-linked glucose. Further, 2 h hydrolysate showed higher reductive capability (20 μg saccharide equivalent to 7.1 μg quercetin) and total antioxidant activity (20 μg saccharide equivalent to 6.7 μg vitamin C). The percent inhibition of 2 h hydrolysate was 42.9% (IC50-15.7 μg/mL) in 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay and 27.4% (IC50-28.4 μg/mL) in 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay. Additionally, 2 h laminarioligosaccharides showed maximum inhibition of α-amylase (30 μg- 32.2% inhibition, IC50-46.6 μg/mL) and α-glucosidase (30 μg- 58.8% inhibition, IC50-25.5 μg/mL) activity. Thus, HCl hydrolysis of laminarin to laminarioligosaccharides could be a promising method for obtaining low molecular weight saccharides with enhanced biological activities.

Hydrolyzed low-molecular-weight polysaccharide from Enteromorpha prolifera exhibits high anti-inflammatory activity and promotes wound healing

Increased anti-inflammatory activity is key to accelerating wound healing. In this study, we prepared three types of water-soluble polysaccharides from Enteromorpha prolifera (PEPs) with different molecular weights by hydrochloric acid hydrolysis and evaluated their anti-inflammatory activity and wound-healing effects. The results showed that, under in vitro conditions, the low molecular-weight polysaccharide (LPEP) exhibited high anti-inflammatory activity and suppressed the production of nitric oxide (NO), tumour necrosis factor α (TNF-α), and interleukins (IL-1β, and IL-6) from macrophage RAW 264.7 cells through the TLR2-dependent NF-κB, PKC/ERK/MAPK, and PI3K/Akt signalling cascades, in a dose-dependent manner. Under in vivo conditions, the LPEP showed remarkable anti-inflammatory activity, effectively reduced TNF-α production within 14 days, and significantly promoted wound healing to reach wound closure rates of up to 99.0%. Further, a higher number of fibroblast cells and a lower number of inflammatory cells were observed around the wound site in LPEP- and amoxicillin-treated rats than in 0.9% NaCl-treated rats. Similarly, faster tissue regeneration and more skin appendages were found for these two treatment groups. This study demonstrates the potential of LPEP as an effective anti-inflammatory agent to reduce inflammation and promote wound healing.