Effects of partial desulfation on antioxidant and inhibition of DLD cancer cell of Ulva fasciata polysaccharide

The relationship between polysaccharide structure and its antioxidant activity needs to be systematically elucidated

Polysaccharides have a wide range of applications due to their excellent antioxidant activity. However, the low purity and unclear structure of polysaccharides have led some researchers to be skeptical about the antioxidant activity of polysaccharides. The current reports on the structure-activity relationship of polysaccharides are sporadic, so there is an urgent need to systematically summarize the antioxidant effects of polysaccharides with clear structures and the relationships between the structures to provide a scientific basis for the development and application of polysaccharides. This paper will systematically elucidate the structure-activity relationship of antioxidant polysaccharides, including the molecular weight, monosaccharide composition, glycosidic linkage, degree of branching, advanced conformation and chemical modification. For the first time, the antioxidant activity of polysaccharides is related to their chemical structure through histogram and radar map, and further studies using principal component analysis and cluster analysis. We critically discussed how the source, chemical structure and chemically modified groups of polysaccharides significantly contribute to their antioxidant activity and summarized the current research status and shortcomings of the structure-activity relationship of antioxidant polysaccharides. This review provides a theoretical basis and new perspective for further research on the structure-activity relationship of antioxidant polysaccharides and the development of natural antioxidants.

Anticancer Mechanism of Astragalus Polysaccharide and Its Application in Cancer Immunotherapy

Astragalus polysaccharide (APS) derived from A. membranaceus plays a crucial role in traditional Chinese medicine. These polysaccharides have shown antitumor effects and are considered safe. Thus, they have become increasingly important in cancer immunotherapy. APS can limit the spread of cancer by influencing immune cells, promoting cell death, triggering cancer cell autophagy, and impacting the tumor microenvironment. When used in combination with other therapies, APS can enhance treatment outcomes and reduce toxicity and side effects. APS combined with immune checkpoint inhibitors, relay cellular immunotherapy, and cancer vaccines have broadened the application of cancer immunotherapy and enhanced treatment effectiveness. By summarizing the research on APS in cancer immunotherapy over the past two decades, this review elaborates on the anticancer mechanism of APS and its use in cancer immunotherapy and clinical trials. Considering the multiple roles of APS, this review emphasizes the importance of using APS as an adjunct to cancer immunotherapy and compares other polysaccharides with APS. This discussion provides insights into the specific mechanism of action of APS, reveals the molecular targets of APS for developing effective clinical strategies, and highlights the wide application of APS in clinical cancer therapy in the future.

The Ethyl Acetate Extract of Caulerpa microphysa Promotes Collagen Homeostasis and Inhibits Inflammation in the Skin

Inflammation and collagen-degrading enzymes' overexpression promote collagen decomposition, which affects the structural integrity of the extracellular matrix. The polysaccharide and peptide extracts of the green alga Caulerpa microphysa (C. microphysa) have been proven to have anti-inflammatory, wound healing, and antioxidant effects in vivo and in vitro. However, the biological properties of the non-water-soluble components of C. microphysa are still unknown. In the present study, we demonstrated the higher effective anti-inflammatory functions of C. microphysa ethyl acetate (EA) extract than water extract up to 16-30% in LPS-induced HaCaT cells, including reducing the production of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α (TNF-α). Furthermore, the excellent collagen homeostasis effects from C. microphysa were proven by suppressing the matrix metalloproteinase-1 (MMP-1) secretion, enhancing type 1 procollagen and collagen expressions dose-dependently in WS1 cells. Moreover, using UHPLC-QTOF-MS analysis, four terpenoids, siphonaxanthin, caulerpenyne, caulerpal A, and caulerpal B, were identified and may be involved in the superior collagen homeostasis and anti-inflammatory effects of the C. microphysa EA extract.

Antitumor effects of polysaccharides from medicinal lower plants: A review

Cancer is one of the leading causes of death worldwide, yet the drugs currently approved for cancer treatment are associated with significant side effects, making it urgent to develop alternative drugs with low side effects. Polysaccharides are natural polymers with ketone or aldehyde groups, which are widely found in plants and have various biological activities such as immunomodulation, antitumor and hypolipidemic. The lower plants have attracted much attention for their outstanding anticancer effects, and many studies have shown that medicinal lower plant polysaccharides (MLPPs) have antitumor activity against various cancers and are promising alternatives with potential development in the food and pharmaceutical fields. Therefore, this review describes the structure and mechanism of action of MLPPs with antitumor activity. In addition, the application of MLPPs in cancer treatment is discussed, and the future development of MLPPs is explored.

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)-β-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.

Ulvan and Ulva oligosaccharides: a systematic review of structure, preparation, biological activities and applications

Ulva is one of the main green algae causing green tide disasters. Ulvan is the primarily component polysaccharide of the cell wall of Ulva and its complex structure and monosaccharide composition resulted in various biological activities. However, the high-value and effective utilization of extracted ulvan have been obstructed by limitations ranging from large molecular weight and low solubility to poor bioavailability. Ulva oligosaccharide obtained by degrading ulvan can not only ideally retain the various biological activities of ulvan very well but also effectively solve the problems of low solubility and poor bioavailability. The preparation and biological activity studies of ulvan and Ulva oligosaccharides have become a hot spot in the field of marine biological resources development research. At present, the comprehensive reviews of ulvan and Ulva oligosaccharides are still scarce. What are overviewed in this paper are the chemical composition, structure, extraction, and purification of ulvan and Ulva oligosaccharides, where research progress on the biological activities of ulvan and Ulva oligosaccharides is summarized and prospected. A theoretical and practical basis has been provided for further research on ulvan and Ulva oligosaccharides, as well as the high-value development and effective utilization of marine algae resources.

Immunomodulatory, Antioxidant, Anticancer, and Pharmacokinetic Activity of Ulvan, a Seaweed-Derived Sulfated Polysaccharide: An Updated Comprehensive Review

Cancer is one of the most worldwide spread diseases and causes maximum death. Treatment of cancer depends on the host immune system and the type of drugs. The inefficiency of conventional cancer treatments as a result of drug resistance, nontargeted delivery, and chemotherapy-related negative side effects has caused bioactive phytochemicals to come into focus. As a result, recent years have seen an increase in research into screening and identifying natural compounds with anticancer properties. Recent studies on the isolation and use of polysaccharides derived from various marine algal species have revealed a variety of biological activities, including antioxidant and anticancer properties. Ulvan is a polysaccharide derived from various green seaweeds of the Ulva species in the family Ulvaceae. It has been demonstrated to have potent anticancer and anti-inflammatory properties through the modulation of antioxidants. It is vital to understand the mechanisms underlying the biotherapeutic activities of Ulvan in cancer and its role in immunomodulation. In this context, we reviewed the anticancer effects of ulvan based on its apoptotic effects and immunomodulatory activity. Additionally, we also focused on its pharmacokinetic studies in this review. Ulvan is the most conceivable candidate for use as a cancer therapeutic agent and could be used to boost immunity. Moreover, it may be established as an anticancer drug once its mechanisms of action are understood. Due to its high food and nutritive values, it can be used as a possible dietary supplement for cancer patients in the near future. This review may provide fresh perspectives on the potential novel role of ulvan, reveal a brand-new cancer-prevention strategy, and improve human health.

Coupling methane and bioactive polysaccharide recovery from wasted activated sludge: A sustainable strategy for sludge treatment

Bioactive polysaccharides (PSs) are valuable resources that can be extracted from waste activated sludge (WAS). The PS extraction process causes cell lysis that may enhance hydrolytic processes during anaerobic digestion (AD) and thus increase the methane production. Thus, coupling PSs and methane recovery from WAS could be an efficient and sustainable sludge treatment. In present study, we comprehensively evaluated this novel process from the efficiencies of different coupling strategies, properties of the extracted PSs, and environmental impacts. The results showed that when the PS extraction was before AD, it produced 76.03 ± 2.00 mL of methane per gram of volatile solids (VS) and afforded a PS yield of 6.3 ± 0.09% (w:w), with a PS sulfate content of 13.15% ± 0.06%. In contrast, when PS extraction was after AD, the methane production decreased to 58.14 ± 0.99 mL of methane per gram of VS and afforded a PS yield of 5.67% ± 0.18% (w:w) in VS, with a PS sulfate content of 2.60% ± 0.04%. When there were two PS extractions before and after AD, the methane production, PS yield and sulfate content were 76.03 ± 2.00 mL of methane per gram of VS, 11.54 ± 0.62% and 8.35 ± 0.12%, respectively. Then, the bioactivity of the extracted PSs was assessed by one anti-inflammation assay and three anti-oxidation assays, and statistical analysis revealed that these four bioactivities of PSs were influenced by their sulfate content, protein content and monosaccharide composition, especially the ratios of arabinose and rhamnose. Furthermore, the environmental impact analysis shows that S1 was the best in five environmental indicators compared with other three non-coupled processes. These findings suggest that the coupling PSs and methane recovery process should be further explored to determine its potential for large-scale sludge treatment.

Production and Characterization of Durvillaea antarctica Enzyme Extract for Antioxidant and Anti-Metabolic Syndrome Effects

In this study, three enzyme hydrolysate termed Dur-A, Dur-B, and Dur-C, were produced from Durvillaea antarctica biomass using viscozyme, cellulase, and α-amylase, respectively. Dur-A, Dur-B, and Dur-C, exhibited fucose-containing sulfated polysaccharide from chemical composition determination and characterization by FTIR analyses. In addition, Dur-A, Dur-B, and Dur-C, had high extraction yields and low molecular weights. All extracts determined to have antioxidant activities by DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), and ferrous ion-chelating methods. All extracts were also able to positively suppress the activities of key enzymes involved in metabolic syndrome: angiotensin I-converting enzyme (ACE), α-amylase, α-glucosidase, and pancreatic lipase. In general, Dur-B exhibited higher antioxidant and higher anti-metabolic syndrome effects as compared to the other two extracts. Based on the above health promoting properties, these extracts (especially Dur-B) can be used as potential natural antioxidants and natural anti-metabolic syndrome agents in a variety of food, cosmetic, and nutraceutical products for health applications.

Extraction, Biochemical Characterization, and Health Effects of Native and Degraded Fucoidans from Sargassum crispifolium

In the current investigation, a native crude fucoidan (Ex) was extracted from Sargassum crispifolium, pretreated by single-screw extrusion, and two degraded fucoidans, i.e., ExAh (degradation of Ex by ascorbic acid) and ExHp (degradation of Ex by hydrogen peroxide), were obtained. The extrusion pretreatment increased the extraction yield of fucoidan by approximately 1.73-fold as compared to the non-extruded sample. Among Ex, ExAh, and ExHp, their molecular weight and chemical compositions varied, but the structural features were similar. ExHp possessed the greatest antioxidant activities among the extracted fucoidans. According to the outcome, ExAh exhibited the maximum immune promoting effects via enhanced NO, TNF-α, IL-1β, IL-6, and IL-10 secretion. Thus, both ExHp and ExAh may potentially be used as an effective antioxidant and as immunostimulant agents, which could be of great value in the development of food and nutraceutical products.

Nutraceutical potentials of algal ulvan for healthy aging

Several theories for aging are constantly put forth to explain the underlying mechanisms. Oxidative stress, DNA dysfunction, inflammation, and mitochondrial dysfunction, along with the release of cytochrome c are some of these theories. Diseases such as type 2 diabetes mellitus, intestinal dysfunction, cardiovascular diseases, hepatic injury, and even cancer develop with age and eventually cause death. Ulva polysaccharides, owing to their special structures and various functions, have emerged as desirable materials for keeping healthy. These polysaccharide structures are found to be closely related to the extraction methods, seaweed strains, and culture conditions. Ulvan is a promising bioactive substance, a potential functional food, which can regulate immune cells to augment inflammation, control the activity of aging-related genes, promote tumor senescence, enhance mitochondrial function, maintain liver balance, and protect the gut microbiome from inflammatory attacks. Given the desirable physiochemical and gelling properties of ulvan, it would serve to improve the quality and shelf-life of food.

Natural Polysaccharides as Preventive and Therapeutic Horizon for Neurodegenerative Diseases

Neurodegenerative diseases are a serious and widespread global public health burden amongst aging populations. The total estimated worldwide global cost of dementia was US$818 billion in 2015 and has been projected to rise to 2 trillion US$ by 2030. While advances have been made to understand different neurodegenerative disease mechanisms, effective therapeutic strategies do not generally exist. Several drugs have been proposed in the last two decades for the treatment of different types of neurodegenerative diseases, with little therapeutic benefit, and often with severe adverse and side effects. Thus, the search for novel drugs with higher efficacy and fewer drawbacks is an ongoing challenge in the treatment of neurodegenerative disease. Several natural compounds including polysaccharides have demonstrated neuroprotective and even therapeutic effects. Natural polysaccharides are widely distributed in plants, animals, algae, bacterial and fungal species, and have received considerable attention for their wide-ranging bioactivity, including their antioxidant, anti-neuroinflammatory, anticholinesterase and anti-amyloidogenic effects. In this review, we summarize different mechanisms involved in neurodegenerative diseases and the neuroprotective effects of natural polysaccharides, highlighting their potential role in the prevention and therapy of neurodegenerative disease.

Are all ulvans equal? A comparative assessment of the chemical and gelling properties of ulvan from blade and filamentous Ulva

Green seaweeds of the genus Ulva are rich in the bioactive sulfated polysaccharide ulvan. Herein we characterise ulvan from Ulva species collected from the Bay of Plenty, Aotearoa New Zealand. Using standardised procedures, we quantified, characterised, and compared ulvans from blade (U. australis, U. rigida, U. sp. B, and Ulva sp.) and filamentous (U. flexuosa, U. compressa, U. prolifera, and U. ralfsii) Ulva species. There were distinct differences in composition and structure of ulvans between morphologies. Ulvan isolated from blade species had higher yields (14.0-19.3 %) and iduronic acid content (IdoA = 7-18 mol%), and lower molecular weight (Mw = 190-254 kDa) and storage moduli (G' = 0.1-6.6 Pa) than filamentous species (yield = 7.2-14.6 %; IdoA = 4-7 mol%; Mw = 260-406 kDa; G' = 22.7-74.2 Pa). These results highlight the variability of the physicochemical properties of ulvan from different Ulva sources, and identifies a morphology-based division within the genus Ulva.

Effect of Oversulfation on the Composition, Structure, and In Vitro Anti-Lung Cancer Activity of Fucoidans Extracted from Sargassum aquifolium

Intensive efforts have been undertaken in the fields of prevention, diagnosis, and therapy of lung cancer. Fucoidans exhibit a wide range of biological activities, which are dependent on the degree of sulfation, sulfation pattern, glycosidic branches, and molecular weight of fucoidan. The determination of oversulfation of fucoidan and its effect on anti-lung cancer activity and related signaling cascades is challenging. In this investigation, we used a previously developed fucoidan (SCA), which served as a native fucoidan, to generate two oversulfated fucoidan derivatives (SCA-S1 and SCA-S2). SCA, SCA-S1, and SCA-S2 showed differences in compositions and had the characteristic structural features of fucoidan by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses. The anticancer properties of SCA, SCA-S1, and SCA-S2 against human lung carcinoma A-549 cells were analyzed in terms of cytotoxicity, cell cycle, Bcl-2 expression, mitochondrial membrane potential (MMP), expression of caspase-3, cytochrome c release, Annexin V/propidium iodide (PI) staining, DNA fragmentation, and the underlying signaling cascades. Our findings indicate that the oversulfation of fucoidan promotes apoptosis of lung cancer cells and the mechanism may involve the Akt/mTOR/S6 pathway. Further in vivo research is needed to establish the precise mechanism whereby oversulfated fucoidan mitigates the progression of lung cancer.

Degradation of Sargassum crassifolium Fucoidan by Ascorbic Acid and Hydrogen Peroxide, and Compositional, Structural, and In Vitro Anti-Lung Cancer Analyses of the Degradation Products

Fucoidans possess multiple biological functions including anti-cancer activity. Moreover, low-molecular-weight fucoidans are reported to possess more bioactivities than native fucoidans. In the present study, a native fucoidan (SC) was extracted from Sargassum crassifolium pretreated by single-screw extrusion, and three degraded fucoidans, namely, SCA (degradation of SC by ascorbic acid), SCH (degradation of SC by hydrogen peroxide), and SCAH (degradation of SC by ascorbic acid + hydrogen peroxide), were produced. The extrusion pretreatment can increase the extraction yield of fucoidan by approximately 4.2-fold as compared to the non-extruded sample. Among SC, SCA, SCH, and SCAH, the chemical compositions varied but structural features were similar. SC, SCA, SCH, and SCAH showed apoptotic effects on human lung carcinoma A-549 cells, as illustrated by loss of mitochondrial membrane potential (MMP), decreased B-cell leukemia-2 (Bcl-2) expression, increased cytochrome c release, increased active caspase-9 and -3, and increased late apoptosis of A-549 cells. In general, SCA was found to exhibit high cytotoxicity to A-549 cells and a strong ability to suppress Bcl-2 expression. SCA also showed high efficacy to induce cytochrome c release, activate caspase-9 and -3, and promote late apoptosis of A-549 cells. Therefore, our data suggest that SCA could have an adjuvant therapeutic potential in the treatment of lung cancer. Additionally, we explored that the Akt/mammalian target of rapamycin (mTOR) signaling pathway is involved in SC-, SCA-, SCH-, and SCAH-induced apoptosis of A-549 cells.

Insights into ulvan lyase: review of source, biochemical characteristics, structure and catalytic mechanism

Ulvan, a kind of polyanionic heteropolysaccharide consisting of 3-sulfated rhamnose, uronic acids (iduronic acid and glucuronic acid) and xylose, has been widely applied in food and cosmetic industries. In addition, ulvan can be converted into fermentable monosaccharides through the cascade system of carbohydrate-active enzymes. Ulvan lyases can degrade ulvan into ulvan oligosaccharides, which is the first step in the fully degradation of ulvan. Various ulvan lyases have been cloned and characterized from marine bacteria and grouped into five polysaccharide lyase (PL) families, namely: PL24, PL25, PL28, PL37 and PL40 families. The elucidation of the biochemical characterization, action pattern and catalytic mechanism of ulvan lyase would definitely enhance our understanding of the deep utilization of marine bioresource and marine carbon cycling. In this review, we summarized the recent progresses about the source and biochemical characteristics of ulvan lyase. Additionally, the structural characteristics and catalytic mechanisms have been introduced in detail. This comprehensive information should be helpful regarding the application of ulvan lyases.

The Antioxidant Activity of Polysaccharides Derived from Marine Organisms: An Overview

Marine-derived antioxidant polysaccharides have aroused extensive attention because of their potential nutritional and therapeutic benefits. However, the comprehensive comparison of identified marine-derived antioxidant polysaccharides is still inaccessible, which would facilitate the discovery of more efficient antioxidants from marine organisms. Thus, this review summarizes the sources, chemical composition, structural characteristics, and antioxidant capacity of marine antioxidant polysaccharides, as well as their protective in vivo effects mediated by antioxidative stress reported in the last few years (2013-2019), and especially highlights the dominant role of marine algae as antioxidant polysaccharide source. In addition, the relationships between the chemical composition and structural characteristics of marine antioxidant polysaccharides with their antioxidant capacity were also discussed. The antioxidant activity was found to be determined by multiple factors, including molecular weight, monosaccharide composition, sulfate position and its degree.

Sulfated Laminaria japonica polysaccharides inhibit macrophage foam cell formation

In this work, a purified Laminaria japonica polysaccharide (LJP61A) was chemically modified to obtain three sulfated polysaccharides (SLJP1, SLJP2 and SLJP3) with different degrees of sulfation using the method of chlorosulfonic acid/pyridine. The effects and underlying mechanism of SLJP1, SLJP2 and SLJP3 on the suppression of macrophage foam cell formation were further investigated using the model of oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation. Results exhibited that the macrophage foam cell formation induced by ox-LDL could be significantly alleviated by these sulfated polysaccharides in a dose-dependent manner. Meanwhile, the enhancement of PPAR-γ mRNA expression in ox-LDL induced macrophages was remarkably inhibited by these sulfated polysaccharides. Moreover, the cellular inflammation induced by ox-LDL could also be remarkably mitigated by these sulfated polysaccharides. These results indicated that the sulfated L. japonica polysaccharides could inhibit the conversion of macrophage into foam cell via obstructing PPAR-γ activation and alleviating cellular inflammation.

Total fractionation and characterization of the water-soluble polysaccharides isolated from Enteromorpha intestinalis

Water-soluble crude polysaccharides (WE) were extracted from the Enteromorpha intestinalis with hot water and further fractionated on a DEAE-52 Cellulose chromatography column and Sepharose CL-6B gel-permeation chromatography to afford one neutral fraction (WE-11) and five acidic fractions (WE-21, WE-31, WE-32, WE-41 and WE-42). Monosaccharide analysis showed that WE-32, WE-41 and WE-42 were all composed of Rha and GlcA, WE-21 and WE-31 contained Man and Rha, and WE-11 was composed of GlcA and Xyl. The molecular weight of WE-11, WE-21, WE-31 WE-32, WE-41 and WE-42 were 2.23 × 10⁵, 1.42 × 10⁵, 1.42 × 10⁵, 2.62 × 10⁴, 2.23 × 10⁵ and 8.09 × 10^4, respectively. Then, antioxidant activities in vitro were investigated on the basis of DPPH radical assay, reducing power assay, hydroxyl radical assay and superoxide radical assay. Of all polysaccharides fractions, WE-32 and WE-41 had relative higher content of sulfate and GlcA. In addition, WE-32 and WE-41 showed relative stronger antioxidant activity and inhibitory activity in vitro. The antioxidant activities of polysaccharides were not a function of a single factor but a combination of several factors, such as monosaccharide composition, molecular weights, protein content, uronic acid and sulfate content.

Compressional-Puffing Pretreatment Enhances Neuroprotective Effects of Fucoidans from the Brown Seaweed Sargassum hemiphyllum on 6-Hydroxydopamine-Induced Apoptosis in SH-SY5Y Cells

In this study, a compressional-puffing process (CPP) was used to pretreat Sargassum hemiphyllum (SH) and then fucoidan was extracted from SH by hot water. Three fucoidan extracts, namely SH1 (puffing at 0 kg/cm²); SH2 (puffing at 1.7 kg/cm²); and SH3 (puffing at 10.0 kg/cm²) were obtained, and their compositions and biological activities were evaluated. The results indicate that CPP increased the extraction yield, total sugar content, and molar ratios of sulfate/fucose of fucoidan and decreased molecular weight and impurities of fucoidan. The SH1-SH3 extracts exhibited characteristics of fucoidan as demonstrated by the analyses of composition, FTIR spectroscopy, NMR spectroscopy, and molecular weight. All SH1-SH3 extracts showed antioxidant activities. The SH1-SH3 extracts protected SH-SY5Y cells from 6-hydroxydopamine (6-OHDA)-induced apoptosis as illustrated by cell cycle distribution, cytochrome c release, activation of caspase-8, -9, and -3, and DNA fragmentation analyses. Additional experiments revealed that phosphorylation of Akt is involved in the opposing effects of SH1-SH3 on 6-OHDA-induced neurotoxicity. SH3 exhibited a relatively high extraction yield, the lowest levels of impurities, and was the most effective at reversing the 6-OHDA-induced neurotoxicity of SH-SY5Y cells among SH1-SH3, which taken together indicate that it may have potential as a candidate therapeutic agent for the preventive therapy of neurodegenerative diseases.

Biological activities and pharmaceutical applications of polysaccharide from natural resources: A review

Pharmacotherapy using natural substances can be currently regarded as a very promising future alternative to conventional therapy. As biological macromolecules, polysaccharide together with protein and polynucleotide, are extremely important biomacromoleules which play important roles in the growth and development of living organism. Polysaccharide is important component of higher plants, membrane of the animal cell and the cell wall of microbes. It is also closely related to the physiological functions. Recently, increasing attention has been paid on polysaccharides as an important class of bioactive natural products. Numerous researches have demonstrated the bioactivities of natural polysaccharides, which lead to the application of polysaccharides in the treatment of disease. In this paper, the various aspects of the investigation results of the bioactivities of polysaccharides were summarized, including its diversity pharmacological applications, such as immunoregulatory, anti-tumor, anti-virus, antioxidation, and hypoglycemic activity, and their application of polysaccharides in the treatment of disease are also discussed. We hope this review can offer some theoretical basis and inspiration for the mechanism study of the bioactivity of polysaccharides.

Sulfated modification, characterization, and antioxidant and moisture absorption/retention activities of a soluble neutral polysaccharide from Enteromorpha prolifera

A purified polysaccharide from Enteromorpha prolifera (PEP) with a molecular mass of 147.8kDa, was prepared by hot-water extraction method and purified by anion-exchange chromatography and gel filtration chromatography. Low Mw polysaccharide of E. prolifera (LEP, 44.8kDa) was obtained by enzymatic degradation. Sulfated derivatives of the two different Mw polysaccharides were synthesized by chlorosulfonic acid/pyridine method, and the degrees of substitution of SPEP and SLEP were 0.57 and 0.81, respectively. Physicochemical properties and FT-IR spectra showed that enzymatic degradation and sulfated modification of polysaccharides were successful. ¹³C NMR analysis showed that the sulfate groups mainly attached to C-6 of rhamnose. Moreover, the study revealed that enzymatic degradation and sulfated modification of polysaccharides improved significantly superoxide, hydroxyl and DPPH radicals scavenging activities in vitro, and enhanced obviously moisture absorption/retention capacities. Therefore, these results demonstrated that molecular weight and sulfate groups had obvious effects on antioxidant activities and moisture absorption/retention abilities of the polysaccharides from E. prolifera.

Physicochemical characterization of the oolong tea polysaccharides with high molecular weight and their synergistic effects in combination with polyphenols on hepatocellular carcinoma

This study was to investigate the synergistic effects of polysaccharides with the molecular weight more than 80kDa (OTPS1) and polyphenols (OTP) isolated from oolong tea on hepatocellular carcinoma (HCC) in vitro and in vivo. The physicochemical properties of OTPS fractions were characterized. The synergistic effects of OTPS1 and OTP were evaluated based on the combination index (CI). Results showed that the highest uronic acid contents (32.96%) and viscosity (239.56mLg^-1), multicavity structure of OTPS1 were contributed to the synergistic effects with OTP (52.17% content of epigallocatechin-3-gallate (EGCG)). OTPS1 and OTP showed the strongest synergism ability on SMMC7721 cells (CI<0.2). Co-administrated with OTPS1 and OTP exhibited the synergistic effects on the tumor proliferation and growth with the CI values of 0.34 and 0.39, respectively. Antioxidative and immune levels of the mice were obviously increased after combination administration. These results suggested that OTPS1 in combination with OTP might be functional supplements for the treatment of HCC.

Inhibition of hydrogen peroxide induced injuring on human skin fibroblast by Ulva prolifera polysaccharide

Ulva prolifera can protect human skin fibroblast from being injured by hydrogen peroxide. This work studied the composition of Ulva prolifera polysaccharide and identified its physicochemical properties. The results showed that the cell proliferation of 0.5mg/mL crude polysaccharide was 154.4% of that in negative control group. Moreover, ROS detection indices, including DCFH-DA, GSH-PX, MDA and CAT, indicated that crude polysaccharide could improve cellular ability to scavenge free radical and decrease the injury on human skin fibroblast by hydrogen peroxide. In purified polysaccharide, the activity of fraction P1-1 was the highest, with 174.6% of that in negative control group. The average molecular weight of P1-1 was 137kD with 18.0% of sulfate content. This work showed the inhibition of hydrogen peroxide induced injuries on human skin fibroblast by Ulva prolifera polysaccharide, which may further evaluate the application of U. prolifera on cosmetics.

Molecular mechanism of a new Laminaria japonica polysaccharide on the suppression of macrophage foam cell formation via regulating cellular lipid metabolism and suppressing cellular inflammation

SCOPE

Laminaria japonica is an important marine vegetable with great health benefits for preventing atherosclerosis. Since the foam cell formation is an important hallmark for the initiation of atherosclerosis, we examined the effect and underlying mechanism of a purified L. japonica polysaccharide (LJP61A) on the suppression of macrophage foam cell formation in this study. The chemical structure was further characterized.

METHODS AND RESULTS

Using oxidized low-density lipoprotein (ox-LDL)-induced foam cell model, we found that the cellular lipid accumulation was significantly attenuated by 25 μg/mL LJP61A. Meanwhile, LJP61A caused a remarkable decrease in mRNA expression of peroxisome proliferator-activated receptor γ that was accompanied by the reduction of CD36 and Acyl coenzyme A: cholesterol acyltransferase-1 mRNA levels, and the enhancement of ATP-binding cassette transporters A1 and scavenger receptor B1 mRNA levels. Besides these, the ox-LDL-induced cellular inflammation was also restricted by LJP61A treatment via mammalian target of rapamycin-mediated Toll-like receptor 2/4-Mitogen-activated protein kinases/nuclear factor kappa-B pathways. The structure of LJP61A was characterized as a repeating unit consisting of →3,6)-α-d-Manp-(1→, →4)-α-d-Manp-(1→, →4)-2-O-acetyl-β-d-Glcp-(1→, →4)-β-d-Glcp-(1→, →6)-4-O-SO3 -β-d-Galp-(1→, →6)-β-d-Galp-(1→, →3)-β-d-Galp-(1→, and a terminal residue of α-d-Glcp-(1→.

CONCLUSION

Our findings suggest that LJP61A inhibits the conversion of macrophage into foam cell via regulating cellular lipid metabolism and suppressing cellular inflammation.

Structural identification and immunostimulating activity of a Laminaria japonica polysaccharide

In the present study, a new water-soluble polysaccharide (LJP-11) was obtained from Laminaria japonica by anion exchange DEAE-cellulose chromatography and Sephacryl S-500 chromatography. The average molecular weight of this polysaccharide was estimated to be about 2.89×10(6) Da by high performance liquid chromatography system. Gas chromatography showed that LJP-11 was composed of arabinose, mannose and glucose in a molar ratio of 1.0:1.16:6.33. LJP-11 contains a long backbone consisting of (1→4)-β-D-GlcpAc, (1→4)-α-D-Glcp, (1→6)-β-D-Glcp and (1→3,6)-α-D-Manp. The 1-linked β-L-Araf was linked to the C-6 of (1→3)-α-D-Manp and the sulfate group was attached to the C-4 of (1→6)-β-D-Glcp. Pharmacological tests displayed that LJP-11 can stimulate macrophages to release NO, IL-6, TNF-α and IL-10 as well as the up-regulation of their gene expressions, indicating LJP-11 has beneficial effects on immunostimulation. Moreover, LJP-11 exhibited positive effects on the translocation of NF-κB p65 from cytoplasm to nucleus and the phosphorylation of IκBα, ERK1/2, JNK1/2 and P38 in macrophages. These results suggested that the activation of MAPK and NF-κB signaling pathways is one of the mechanisms responsible for the immunostimulating activity of LJP-11.