Ulvans are not equal - Linkage and substitution patterns in ulvan polysaccharides differ with Ulva morphology.

Ulva are hardy green seaweeds that contain the sulfated polysaccharide ulvan and grow in two distinct morphologies: foliose and tubular. The authors hypothesise that ulvan from tubular species are more structurally complex than ulvans from foliose species. Herein, using standardised methods, the glycosyl linkage positions and sulfate ester substitutions of constituent monosaccharides of ulvan isolated from foliose (U. lacinulata and U. stenophylloides) and tubular (U. prolifera and U. ralfsii) species of Ulva were investigated. Comparison of native ulvans with 80 and 100 °C desulfated counterparts indicated that 4-linked rhamnose is predominantly 3-O-sulfated in all four ulvans. Ulvans from the foliose species predominantly contained →3,4)-Rhap-(1→, →4)-GlcAp-(1→ and →4)-IdoAp-(1→, collectively accounting for 67 to 81 mol% of the total linkages. In contrast, these same linkages in ulvans from the tubular species only collectively accounted for 29 to 36 mol%. Instead, ulvan from tubular species contained a combination of →2,3,4)-Rhap-(1→, terminal Rhap-(1→, →4)-GlcAp-(1→, →4)-Xylp-(1→, and/or →4)-Galp-(1→ in high proportions; some of the latter three residues were also likely O-2 sulfated. The results presented here suggest that ulvan from foliose species are predominantly unbranched polysaccharides composed of repeat disaccharides while ulvans from tubular species contain a greater diversity of branch and sulfate substitution locations.

Characterization and Biological Activities of the Ulvan Polysaccharide-Rich Fraction Obtained from Ulva rigida and Ulva pseudorotundata and Their Potential for Pharmaceutical Application.

Seaweed from the genus Ulva (Ulvales, Chlorophyta) has a worldwide distribution and represents a potential biomass source for biotechnological applications. In the present study, we investigated the ulvan polysaccharide-rich fraction (UPRF) isolated from two Ulva species (U. rigida and U. pseudorotundata), naturally occurring on the Spanish Mediterranean coast. Chemical characterization of UPRFs was performed in order to explore the polysaccharides' composition. Biological assessments of UPRFs were compared by antioxidant activity and in vitro toxicity tests in the human cell lines: HCT-116 (colon cancer), G-361 (malignant melanoma), U-937 (leukemia), and HaCaT cells (immortalized keratinocytes). Chemical analysis revealed that both UPRFs presented rhamnose as the major relative sugar constituent, followed by glucose in U. rigida and xylose in U. pseudorotundata. Both also presented glucuronic acid, galactose, ribose, and mannose as the remaining monosaccharides. Similar antioxidant activity was obtained, where we observed increased activity in response to increased polysaccharide concentrations. Both UPRFs presented moderate toxicity against HCT-116 cell lines and a selectivity index ≥ 3, suggesting a good potential for use in pharmaceutical products.

Flash extraction of ulvan polysaccharides from marine green macroalga Ulva linza and evaluation of its antioxidant and gut microbiota modulation activities.

In this study, flash extraction was used to rapidly extract water-soluble polysaccharides from Ulva linza. The optimal extraction process for the flash extraction was determined by Box-Behnken design with extraction temperature 80 °C, extraction time 117 s, liquid-solid ratio 46:1 (mL/g) and a corresponding yield of 18.5 %. The crude Ulva linza polysaccharides (CULP) were subsequently isolated by chromatography technology to obtain purified Ulva linza polysaccharide (ULP) and characterized by monosaccharide composition and molecular weight determination analysis. Furthermore, the antioxidant bioactivity of ULP was studied and the results revealed that it had a good scavenging effect on DPPH, ABTS and OH, with IC50 values of 149.2 µg/mL, 252.5 µg/mL and 1073 µg/mL, respectively. After in vitro fermentation by human fecal microbiota, the pH value of fermentation culture significantly decreased to 5.06, suggesting that ULP could be hydrolyzed and utilized by gut microbiota. The abundance of beneficial bacteria including Bacteroides, Parabacteroides and Faecalibacterium was improved. Meanwhile, the relative abundance of Prevotella, Blautia and Ruminococcus was decreased, and the low ratio of these organisms might reveal positive effects on maintaining the balance of gut microbial biodiversity. These results suggested that the composition of the human gut microbiota could be modulated by ULP, and ULP might possess the potential to maintain gut homeostasis and improve human intestinal health.

In-situ electrospinning with precise deposition of antioxidant nanofiber facial mask loaded with Enteromorpha prolifera polysaccharides.

In order to fabricate a novel antioxidant nanofiber facial mask, a metal cone modified in-situ electrospinning with precise deposition was employed by utilizing Enteromorpha prolifera polysaccharides (EPPs). The metal cone could control the deposition area to achieve precise fabrication of facial mask on skin. The EPPs exhibited remarkable antioxidant ability, as evidenced by the half-maximal inhibitory concentrations (IC50) of 1.44 mg/mL and 0.74 mg/mL against DPPH and HO• free radicals, respectively. The antioxidant ability of the facial mask was improved by elevating the electrospinning voltage from 15 kV to 19 kV, due to the improved release capacity of EPPs by 7.09 %. Moreover, the facial mask demonstrated robust skin adhesion and moisture-retaining properties compared with commercial facial mask, which was benefited by the in-situ electrospinning technology. Furthermore, cytotoxicity assay, animal skin irritation test, and ocular irritation test collectively affirmed the safety of the facial mask. Thus, this research introduces a novel in situ electrospinning with precise deposition method and a natural antioxidant additive for preparing facial mask.

Structural Characterization and Cytotoxic Activity Evaluation of Ulvan Polysaccharides Extracted from the Green Algae Ulva papenfussii.

Ulvan, a sulfated heteropolysaccharide with structural and functional properties of interest for various uses, was extracted from the green seaweed Ulva papenfussii. U. papenfussii is an unexplored Ulva species found in the South China Sea along the central coast of Vietnam. Based on dry weight, the ulvan yield was ~15% (w/w) and the ulvan had a sulfate content of 13.4 wt%. The compositional constitution encompassed L-Rhamnose (Rhap), D-Xylose (Xylp), D-Glucuronic acid (GlcAp), L-Iduronic acid (IdoAp), D-Galactose (Galp), and D-Glucose (Glcp) with a molar ratio of 1:0.19:0.35:0.52:0.05:0.11, respectively. The structure of ulvan was determined using High-Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Nuclear Magnetic Resonance spectroscopy (NMR) methods. The results showed that the extracted ulvan comprised a mixture of two different structural forms, namely ("A3s") with the repeating disaccharide [→4)-ß-D-GlcAp-(1→4)-α-L-Rhap 3S-(1→]n, and ("B3s") with the repeating disaccharide [→4)-α-L-IdoAp-(1→4)-α-L-Rhap 3S(1→]n. The relative abundance of A3s, and B3s was 1:1.5, respectively. The potential anticarcinogenic attributes of ulvan were evaluated against a trilogy of human cancer cell lineages. Concomitantly, Quantitative Structure-Activity Relationship (QSAR) modeling was also conducted to predict potential adverse reactions stemming from pharmacological interactions. The ulvan showed significant antitumor growth activity against hepatocellular carcinoma (IC50 ≈ 90 µg/mL), human breast cancer cells (IC50 ≈ 85 µg/mL), and cervical cancer cells (IC50 ≈ 67 µg/mL). The QSAR models demonstrated acceptable predictive power, and seven toxicity indications confirmed the safety of ulvan, warranting its candidacy for further in vivo testing and applications as a biologically active pharmaceutical source for human disease treatment.

Enzyme-Assisted Extraction of Ulvan from the Green Macroalgae Ulva fenestrata.

Ulvan is a sulfated polysaccharide extracted from green macroalgae with unique structural and compositional properties. Due to its biocompatibility, biodegradability, and film-forming properties, as well as high stability, ulvan has shown promising potential as an ingredient of biopolymer films such as sustainable and readily biodegradable biomaterials that could replace petroleum-based plastics in diverse applications such as packaging. This work investigates the potential of Ulva fenestrata as a source of ulvan. Enzyme-assisted extraction with commercial cellulases (Viscozyme L and Cellulysin) and proteases (Neutrase 0.8L and Flavourzyme) was used for cell wall disruption, and the effect of the extraction time (3, 6, 17, and 20 h) on the ulvan yield and its main characteristics (molecular weight, functional groups, purity, and antioxidant capacity) were investigated. Furthermore, a combined process based on enzymatic and ultrasound extraction was performed. Results showed that higher extraction times led to higher ulvan yields, reaching a maximum of 14.1% dw with Cellulysin after 20 h. The combination of enzymatic and ultrasound-assisted extraction resulted in the highest ulvan extraction (17.9% dw). The relatively high protein content in U. fenestrata (19.8% dw) makes the residual biomass, after ulvan extraction, a potential protein source in food and feed applications.

Biochemical characterization of a new ulvan lyase and its applicability in utilization of ulvan and preparation of ulva oligosaccharides.

Ulva is globally distributed specie and has a high economic value. Ulvan is one of the main active substances in Ulva, which has a variety of biological properties. Ulvan lyase degrades ulvan through a ß-elimination mechanism which cleaves the ß-glycosidic bond between Rha3S and GlcA or IdoA. The complex monosaccharide composition of ulvan makes it promising for use in food and pharmaceutical applications. This thesis explores a putative ulvan lyase from Alteromonas sp. KUL_42. We expressed and purified the protein, performed a series of characterizations and signal peptide had been removed. The results showed that the protein molecular weight of ULA-2 was 53.97 kDa, and it had the highest catalytic activity at 45 °C and pH 8.0 in Tris-HCl buffer. The Km and Vmax values were 2.24 mg · mL-1 and 2.048 µmol · min-1 · mL-1, respectively. The activity of ULA-2 was able to maintain more than 80% at 20 ~ 30 °C. ESI-MS analysis showed that the primary end-products were mainly disaccharides to tetrasaccharides. The study of ULA-2 enriches the ulvan lyase library, promotes the development and high-value utilization of Ulva resources, and facilitates further research applications of ulvan lyase in ulva oligosaccharides.

Sustainable biorefining and bioprocessing of green seaweed (Ulva spp.) for the production of edible (ulvan) and non-edible (polyhydroxyalkanoate) biopolymeric films.

A sustainable biorefining and bioprocessing strategy was developed to produce edible-ulvan films and non-edible polyhydroxybutyrate films. The preparation of edible-ulvan films by crosslinking and plasticisation of ulvan with citric acid and xylitol was investigated using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) analysis. The edible ulvan film was tested for its gut-friendliness using Lactobacillus and Bifidobacterium spp. (yoghurt) and was shown to improve these gut-friendly microbiome's growth and simultaneously retarding the activity of pathogens like Escherchia coli and Staphylococcus aureus. Green macroalgal biomass refused after the extraction of ulvan was biologically processed by dark fermentation to produce a maximum of 3.48 (± 0.14) g/L of volatile fatty acids (VFAs). Aerobic processing of these VFAs using Cupriavidus necator cells produced 1.59 (± 0.12) g/L of biomass with 18.2 wt% polyhydroxybutyrate. The present study demonstrated the possibility of producing edible and non-edible packaging films using green macroalgal biomass as the sustainable feedstock.

Assessing pharmaceuticals in the green seaweed Ulva lactuca through a multi-residue UHPLC-ToF-MS strategy.

Seaweeds have become an important asset in several sectors, including the food and feed industries, cosmetics, and pharmaceuticals, among others. Whether harvested or reared, interest in algae has been growing worldwide due to the resources they offer, including proteins, vitamins, minerals, carbohydrates, essential fatty acids, and dietary fiber, as well as sources of biologically active compounds. However, given their morphology and physiology, as well as their harvest and cultivation environments, algae are prone to the presence of hazards, including pharmaceuticals taken up from the water. Thus, to ensure human and animal safety as well as environmental health, monitoring is essential. Therefore, this work describes the development and validation of a sensitive screening and confirmatory analytical method based on ultra-high-performance liquid chromatography coupled with time-of-flight mass spectrometry (UHPLC-ToF-MS). This multi-residue method enables the determination of 62 pharmaceuticals distributed between 8 therapeutic classes and was fully validated according to Commission Implementing Regulation (EU) 2021/808.

Chemical Composition and Antioxidant Potential of Five Algae Cultivated in Fully Controlled Closed Systems.

In this study, the chemical composition and antioxidant profile of five edible macroalgae, Fucus vesiculosus, Palmaria palmata, Porphyra dioica, Ulva rigida, and Gracilaria gracilis, cultivated in fully controlled closed systems, were determined. Protein, carbohydrates, and fat contents ranged between 12.4% and 41.8%, 27.6% and 42.0%, and 0.1% and 3.4%, respectively. The tested seaweeds presented considerable amounts of Ca, Mg, K, Mn, and Fe, which reinforce their favorable nutritional profile. Regarding their polysaccharide composition, Gracilaria gracilis and Porphyra dioica were rich in sugars common to agar-producing red algae, and Fucus vesiculosus was composed mainly of uronic acids, mannose, and fucose, characteristic of alginate and fucoidans, whereas rhamnose and uronic acid, characteristic of ulvans, predominated in Ulva rigida. Comparatively, the brown F. vesiculosus clearly stood out, presenting a high polysaccharide content rich in fucoidans, and higher total phenolic content and antioxidant scavenging activity, determined by DPPH and ABTS. The remarkable potential of these marine macroalgae makes them excellent ingredients for a wide range of health, food, and industrial applications.

Synergistic antibacterial effects of Ulva lactuca methanolic extract alone and in combination with different antibiotics on multidrug-resistant Klebsiella pneumoniae isolate.

Various antibiotics are available, including gentamicin, chloramphenicol, ampicillin, amoxicillin, and streptomycin, but they have some restrictions. Many microorganisms are resistant to these medications. A new antimicrobial source must be found or developed to solve this issue. Inhere, extract from seaweeds Ulva lactuca was investigated for its antibacterial activity using a well diffusion assay against Klebsiella pneumoniae, and a promising inhibition zone diameter was recorded to be 14.04 mm. The biochemical structure of the antibacterial compound was determined via GC-MS and FTIR analysis. Also, a micro-dilution assay was used to calculate the minimum concentration that makes inhibition (MIC) to be 1.25 mg/ml from U. extract reliable to prevent the visibility of any bacterial growth, this was followed by examining the antibacterial effect of U. Lactuca methanolic extract alone and the synergetic effect of U. Lactuca methanolic extract in combination with two different antibiotics (gentamicin and chloramphenicol). This was assayed by the agar well diffusion method to achieve promising and strong inhibiting power against K. pneumoniae. It was deduced that the maximum synergism could be achieved by adding 2.5 mg/ml of Ulva methanolic extract to gentamicin (4 µg/ml), and the results were illustrated obviously via transmission electron microscope in which severe morphological deteriorations were experienced by the treated cells. From this study, we can conclude that U. lactucae extract has the power to aid antibiotics in reducing the growth of pathogenic K. pneumoniae.

Process and technoeconomic analysis of bioethanol production from residual biomass of marine macroalgae Ulva lactuca.

In the present work, the residual biomass of the green seaweed Ulva lactuca was chosen as feedstock to undergo separate hydrolysis and fermentation process to produce bioethanol. The hydrolysis process was optimized for cellulase, biomass, temperature, and time conditions. The maximum yield of fermentable sugars was 13.48 mg/mL. The recovered hydrolysate was subjected to fermentation using Saccharomyces cerevisiae. The bioethanol produced was subjected to gas chromatography coupled mass spectrometry analysis to determine the presence of ethanol. The technical performance and economic feasibility of the bioethanol production from U. lactuca were evaluated using the lab-scale data obtained for optimized conditions. The plant capacity was 10 MT/day of bioethanol production. The plant's capital investment and annual operating cost were 3.18 M$ and 0.86 M$ respectively. The total annual revenue of the plant was 1.41 M$. The minimum selling price of bioethanol was 0.47 $/kg. The ROI, payback period, IRR and NPV of the plant were 16.99 %, 5.89 years, 11.57 % and 291,000 $ respectively. The utilization of residual biomass for biofuels helps to develop an economic and environmentally sustainable plant.

The therapeutic potential for senescence-associated diabetes of green alga Enteromorpha prolifera polysaccharide.

DEAE-52 and Sephadex G-100 columns were used to isolate Enteromorpha prolifera polysaccharide (EPP), which contains α-L-Rhap-(1 â†’ 4)-α-L-Arap-(1 â†’ 2)-α-L-Rhap-(1 â†’ 3)-ß-D-Galp-(1 â†’ structural fragment, along with α-L-Rhap-(1 â†’ and →2)-α-L-Rhap-(1 â†’ 3)-ß-D-GlcpA-(1 â†’ side bonds that connect to →3,6)-ß-D-Galp-(1→. The anti-ageing and hypoglycemic activities of EPP were assessed using an ageing diabetic mice model, and the revealed that EPP could improve glucose metabolism-associated parameters and inhibit the expression of ageing associated genes, including p16INK4a, p38 MAPK, NOX-1, VEGF, and AGER, thus preventing liver damage. Moreover, gut microbiota profiling revealed that EPP significantly increased the abundances of o_Lactobacillaceae, c_Bacilli, f_Lactobacillaceae, g_Lactobacillus, and p_Firmicutes, showing that EPP has a probiotic effect on enhancing the beneficial microbiota in ageing diabetic mice. In summary, EPP might serve as a potential bioactive compound to alleviate hyperglycaemia and ageing in diabetic in mice and further clinical studies are required to verify these effects.

Microwave-assisted extraction of Ulva spp. including a stage of selective coagulation of ulvan stimulated by a bio-ionic liquid.

Microwave-assisted hydrothermal processing was proposed to recover high valuable compounds with antioxidant and gelling features from Ulva spp. green seaweed. The influence of the extraction conditions on the solubles, ulvan fraction and residual solid phase was studied to achieve a global valorization of the seaweed. A particular emphasis was placed on the selective coagulation of ulvan stimulated by a bio-ionic liquid during the extraction process. The achieved outcomes indicated that the selected microwave treatment exhibited a notable impact on the phytochemical properties of the soluble extracts, with the highest values of sulfate and protein content at 160 °C, and the highest antioxidant features at 200 °C. The most prominent molecular weight distributions were also identified for systems hydrothermal treated at 160 °C. The ulvan analyses showed that those extracted after microwave treatment at 160 °C showed the highest yields, molecular weight and the strongest gel features from the rheological point of view. The presence of the chloride chlorine during the extraction process favored the ulvan performance and the enhancement of the corresponding viscoelastic properties.

Electromagnetic absorption enhancing mechanisms by modified biochar derived from Enteromorpha prolifera: a combined experimental and simulation study.

Although the rapid advances of wireless technologies and electronic devices largely improve the quality of life, electromagnetic (EM) pollution increases the risk of exposure to EM radiation. Developing high-efficiency absorbers with a rational structure and wideband characteristics is of great significance to eliminate radiation pollution. Herein, Enteromorpha prolifera derived biochar which would provide a suitable surface and multiple polarizations has been prepared as the supporter to anchor nanoparticles. In addition, theoretical simulation results further confirm that radar wave scattering could be largely inhibited after coating with absorbing materials. As a result, the hybrid absorbers achieve remarkable EM absorption properties attributed to the synergistic magnetic-dielectric loss. Elaborate compositional and structural characterization studies indicate that the absorber has a large specific area and numerous polarization centers, which would make full use of waste biomass as light weight and broadband high-performance EM absorption materials.

Marine Alga Ulva fasciata-Derived Molecules for the Potential Treatment of SARS-CoV-2: An In Silico Approach.

SARS-CoV-2 is the causative agent of the COVID-19 pandemic. This in silico study aimed to elucidate therapeutic efficacies against SARS-CoV-2 of phyco-compounds from the seaweed, Ulva fasciata. Twelve phyco-compounds were isolated and toxicity was analyzed by VEGA QSAR. Five compounds were found to be nonmutagenic, noncarcinogenic and nontoxic. Moreover, antiviral activity was evaluated by PASS. Binding affinities of five of these therapeutic compounds were predicted to possess probable biological activity. Fifteen SARS-CoV-2 target proteins were analyzed by the AutoDock Vina program for molecular docking binding energy analysis and the 6Y84 protein was determined to possess optimal binding affinities. The Desmond program from Schrödinger's suite was used to study high performance molecular dynamic simulation properties for 3,7,11,15-Tetramethyl-2-hexadecen-1-ol-6Y84 for better drug evaluation. The ligand with 6Y84 had stronger binding affinities (-5.9 kcal/mol) over two standard drugs, Chloroquine (-5.6 kcal/mol) and Interferon α-2b (-3.8 kcal/mol). Swiss ADME calculated physicochemical/lipophilicity/water solubility/pharmacokinetic properties for 3,7,11,15-Tetramethyl-2-hexadecen-1-ol, showing that this therapeutic agent may be effective against SARS-CoV-2.

Optimisation of Vitamin B12 Extraction from Green Edible Seaweed (Ulva lactuca) by Applying the Central Composite Design.

Vitamin B12, only found naturally in animal-based foods, is essential for brain functions and various chemical reactions in the human body. Insufficient vitamin B12 leads to vitamin B12 deficiency, common among strict vegetarians due to their limited intake of animal-based foods. Nevertheless, extensive studies have demonstrated that macroalgae, specifically the Ulva lactuca species, are rich in vitamin B12 and could be further exploited in future dietary applications. In the current study, the ideal extraction method of vitamin B12 from dried U. lactuca was developed and optimised to achieve the maximum vitamin B12 yield. The effects of several extraction parameters, including the solvent-to-solvent, methanol:water (MeOH:H2O), and solute-to-solvent ratios, and pH on the total vitamin B12 content were analysed through a two-level factorial and central composite design. The highest vitamin B12 content, particularly cyanocobalamin (CN-Cbl), was recovered through the ultrasonic-assisted extraction (UAE) of oven-dried U. lactuca at 3 g:60 mL of solute-to-solvent and 25:75% of MeOH to H2O ratios at pH 4. The extraction of CN-Cbl from oven-dried U. lactuca that employed the UAE method has elevated CN-Cbl content recovery compared to other extraction methods.

Immunomodulatory Activity In Vitro and In Vivo of a Sulfated Polysaccharide with Novel Structure from the Green Alga Ulvaconglobata Kjellman.

Algae accumulate large amounts of polysaccharides in their cell walls or intercellular regions. Polysaccharides from algae possess high potential as promising candidates for marine drug development. In this study, a sulfated polysaccharide, UCP, from the green alga Ulva conglobata Kjellman was obtained by water extraction, anion-exchange, and size-exclusion chromatography purification, and its structure was characterized by a combination of chemical and spectroscopic methods. UCP mainly consisted of →4)-α/ß-l-Rhap-(1→, →4)-ß-d-Xylp-(1→ and →4)-ß-d-GlcAp-(1→ residues. Sulfate ester groups were substituted mainly at C-3 of →4)-l-Rhap-(1→ and C-2 of →4)-ß-d-Xylp-(1→. Partial glycosylation was at C-2 of →4)-α-l-Rhap-(1→ residues. UCP possessed a potent immunomodulatory effect in vitro, evaluated by the assays of lymphocyte proliferation and macrophage phagocytosis. The immunomodulatory activity of UCP in vivo was further investigated using immunosuppressive mice induced by cyclophosphamide. The results showed that UCP markedly increased the spleen and thymus indexes and ameliorated the cyclophosphamide-induced damage to the spleen and thymus. UCP could increase the levels of white blood cells, lymphocytes, and platelets, and improve the hematopoietic inhibition caused by cyclophosphamide. Moreover, UCP significantly promoted the secretions of the immunoglobulin (Ig)G, IgE, and IgM. The data demonstrated that UCP is a novel sulfated polysaccharide and may be a promising immunomodulatory agent.

Comparison of the Antioxidant Properties of Green Macroalgae from Diverse European Water Habitats by Use of Several Semi-Quantitative Assays.

Nowadays, algae are becoming more and more popular as a food group rich in nutrients, cosmetic raw materials full of antioxidants or valuable dietary supplements. They are of interest for the industry because they are found almost all over the world, in all climatic zones, both in fresh and salt waters. The aim of this study was to take a broad look at green algae (Chlorophyta) and to show how large the variability of the content of active compounds may depend on the species and the place and time of sample collection. Particular attention was paid to compounds with antioxidant activity, whose simplified profiles were created on the basis of complementary, semi-quantitative methods. Additionally, time-yield extraction optimizations were performed. Three different specimens of Ulva lactuca were compared: from the coastal zone of the Baltic Sea, from the open Baltic Sea area around Bornholm and Ulva spiralis (Ulva lactuca polymorph) from the Atlantic Ocean. The studied algae of the Cladophora genera were three different species of freshwater algae from various habitats: a lake (Cladophora glomerata), a river (Cladophora rivularis) and aquarium farming (Cladophora aegagropila, syn. Aegagropila linnaei). The content of antioxidants and the extraction efficiency varied significantly depending on the species.

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-1ß, 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.