In vitro and in vivo immunomodulatory activity of sulfated polysaccharide from Porphyra haitanensis

Recent progress in Porphyra haitanensis polysaccharides: Extraction, purification, structural insights, and their impact on gastrointestinal health and oxidative stress management

Porphyra haitanensis, a red seaweed species, represents a bountiful and sustainable marine resource. P. haitanensis polysaccharide (PHP), has garnered considerable attention for its numerous health benefits. However, the comprehensive utilization of PHP on an industrial scale has been limited by the lack of comprehensive information. In this review, we endeavor to discuss and summarize recent advancements in PHP extraction, purification, and characterization. We emphasize the multifaceted mechanisms through which PHP promotes gastrointestinal health. Furthermore, we present a summary of compelling evidence supporting PHP's protective role against oxidative stress. This includes its demonstrated potent antioxidant properties, its ability to neutralize free radicals, and its capacity to enhance the activity of antioxidant enzymes. The information presented here also lays the theoretical groundwork for future research into the structural and functional aspects of PHP, as well as its potential applications in functional foods.

Immunomodulatory activities of polysaccharides isolated from Amauroderma rugosum (Blume and T. Nees) Torrend and their structural characterization

Amauroderma rugosum (Blume and T. Nees) Torrend is a traditionally well-known mushroom that is used for the treatment of cancer. In order to evaluate the pharmacological activities of A. rugosum polysaccharides, the mushroom powder was subjected to hot water extraction and pure polysaccharides (ARPs) were isolated by gel-filtration method. Three important APRs called ARP-1, ARP-2 and ARP-5 were identified with average molecular weights of 1494, 450, and 7 kDa respectively. Their antioxidant abilities were estimated by examining free radical scavenging potential against 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical (ABTS●+), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH●), and hydroxyl radical. Immunomodulatory potentials of these ARPs were determined using murine macrophage cells. These polysaccharides exhibited high antioxidant abilities and stimulated mouse macrophages leading to the generation of tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Excellent activities were displayed by ARP-1 and APR-2. Gas chromatography and spectroscopic (FT-IR and NMR) methods were employed in order to carry out their structural characterisation. The two high molecular weight ARPs (ARP-1 and ARP-2) displayed β-(1 → 3)-D-glucan backbone structure with branching of β-(1 → 6)-d-glucopyranosyl. These observations suggest high potential of ARPs for immunotherapeutic applications.

Exploring the therapeutic potential of porphyran extracted from Porphyra haitanensis in the attenuation of DSS-induced intestinal inflammation

Ulcerative colitis is a chronic, spontaneous inflammatory bowel disease that primarily affects the colon. This study aimed to explore how Porphyra haitanensis porphyran (PHP) modulates the immune response and the associated mechanisms that alleviate dextran sulphate sodium-induced colitis in mice. Histological assessments via H&E staining and AB-PAS staining revealed that PHP intervention partially restored the number of goblet cells and improved intestinal mucosal function. Immunohistochemical and Western blot analyses of claudin-1, occludin, and MUC-2 demonstrated that PHP could repair the intestinal barrier and reduce colon damage by upregulating the expression of these proteins. PHP intervention was associated with a decrease in pro-inflammatory cytokine expression and an increase in anti-inflammatory cytokine expression. Moreover, the expression of proteins involved in intestinal immune homing, such as CCR-9, CCL-25, MAdCAM-1, and α4β7, was significantly suppressed in response to PHP treatment. Conversely, PHP upregulates the expression of CD40 and TGF-β1, both of these can promote healing and reduce inflammation in the gut lining. This study demonstrates that PHP can ameliorate ulcerative colitis by enhancing the intestinal barrier and modulating immune responses. These findings offer valuable insights into the potential utility of P. haitanensis as a promising natural product for managing ulcerative colitis.

In vitro immune-enhancing effects of Platycodon grandiflorum combined with Salvia plebeian via MAPK and NF-κB signaling in RAW264.7 cells

The immune-enhancing activity of the combination of Platycodon grandiflorum and Salvia plebeian extracts (PGSP) was evaluated through macrophage activation using RAW264.7 cells. PGSP (250-1000 μg/mL) showed a higher release of NO in a dose-dependent manner. The results showed that PGSP could significantly stimulate the production of PGE2, COX-2, TNF-α, IL-1β, and IL-6 in RAW264.7 cells and promote iNOS, COX-2, TNF-α, IL-1β, IL-4, and IL-6 mRNA expression. Western blot analysis demonstrated that the protein expression of iNOS and COX-2 and the phosphorylation of ERK, JNK, p38, and NF-κB p65 were greatly increased in PGSP-treated cells. PGSP also promoted the phagocytic activity of RAW264.7 cells. All these results indicated that PGSP might activate macrophages through MAPK and NF-κB signaling pathways. Taken together, PGSP may be considered to have immune-enhancing activity and might be used as a potential immune-enhancing agent.

Advances in sulfonated modification and bioactivity of polysaccharides

Polysaccharides, as biological macromolecules, are widely found in plants, animals, fungi, and bacteria and exhibit various biological activities. However, many natural polysaccharides exhibit low or non-existent biological activities because of their high molecular weights and poor water solubility, limiting their application in many fields. Sulfonation is one of the most effective chemical modification methods to improve physicochemical properties and biological activities of natural polysaccharides or even impart natural polysaccharides with new biological activities. Therefore, sulfonated polysaccharides have attracted increasing attention because of their antioxidant, anticoagulant, antiviral, and immunomodulatory properties. This paper reviews the recent advances in the sulfonation of polysaccharides, including preparation, characterization, and biological activities of sulfonated polysaccharides, and provides a theoretical basis for wide applications of sulfonated polysaccharides.

Sulfated Galactans from Agarophytes: Review of Extraction Methods, Structural Features, and Biological Activities

Agarophytes are important seaweeds of the Rhodophyta type, which have been highly exploited for industrial use as sources of a widely consumed polysaccharide of agar. In addition to that, sulfated galactans (SGs) from agarophytes, which consist of various functional sulfate groups, have attracted the attention of scientists in current studies. SGs possess various biological activities, such as anti-tumor, anticoagulant, anti-inflammatory, antioxidant, anti-obesity, anti-diabetic, anti-microbial, anti-diarrhea, and gut microbiota regulation properties. Meanwhile, the taxonomy, ecological factors, i.e., environmental factors, and harvest period, as well as preparation methods, i.e., the pretreatment, extraction, and purification conditions, have been found to influence the chemical compositions and fine structures of SGs, which have, further, been shown to have an impact on their biological activities. However, the gaps in the knowledge of the properties of SGs due to the above complex factors have hindered their industrial application. The aim of this paper is to collect and systematically review the scientific evidence about SGs and, thus, to pave the way for broader and otherwise valuable industrial applications of agarophytes for human enterprise. In the future, this harvested biomass could be sustainably used not only as a source of agar production but also as natural materials in functional food and pharmaceutical industries.

Study on Immunoregulatory Effects of Fucoidan from Sargassum graminifolium In Vivo and Immunoactivation Activity of Its Fecal Fermentation Products Using Co-Culture Model

Fucoidan, brown seaweed-derived dietary fibers (DFs), can be considered a promising candidate for modulating immune responses. Due to its structural complexity and diversity, it is unclear whether Sargassum graminifolium fucoidans (SGFs) also show marvelous immunoregulatory effects. In the present study, two fractions, SGF-1 and SGF-2, were purified from SGFs by DEAE-Sepharose Fast Flow and Sephacryl S-400 HR column chromatography. We investigated the in vivo immune regulatory activity of SGF-2 and explored the immune activation of SGF-2 fecal fermentation products with in vitro fecal fermentation combined with a Caco-2/RAW264.7 co-culture system. In vivo results exhibited that SGF-2 could elevate the thymus/spleen indices, CD8+ splenic T lymphocyte subpopulations, and CD4+ Foxp3+ splenic Tregs. The 16S high-throughput sequencing results showed that SGF-2 administration significantly increased the relative abundance of Lactobacillus, Alloprevotella, Ruminococcus, and Akkermansia. In addition, it was found that SGF-2 fermented by feces could significantly improve the phagocytosis, NO, and cytokine (TNF-α, IL-6, and IL-10) production of macrophages in the co-culture system. These results indicated that SGFs have the potential to modulate immunity and promote health by affecting the gut microbiota.

Natural polysaccharides exert anti-tumor effects as dendritic cell immune enhancers

With the development of immunotherapy, the process of tumor treatment is also moving forward. Polysaccharides are biological response modifiers widely found in plants, animals, fungi, and algae and are mainly composed of monosaccharides covalently linked by glycosidic bonds. For a long time, polysaccharides have been widely used clinically to enhance the body's immunity. However, their mechanisms of action in tumor immunotherapy have not been thoroughly explored. Dendritic cells (DCs) are a heterogeneous population of antigen presenting cells (APCs) that play a crucial role in the regulation and maintenance of the immune response. There is growing evidence that polysaccharides can enhance the essential functions of DCs to intervene the immune response. This paper describes the research progress on the anti-tumor immune effects of natural polysaccharides on DCs. These studies show that polysaccharides can act on pattern recognition receptors (PRRs) on the surface of DCs and activate phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT), mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), Dectin-1/Syk, and other signalling pathways, thereby promoting the main functions of DCs such as maturation, metabolism, antigen uptake and presentation, and activation of T cells, and then play an anti-tumor role. In addition, the application of polysaccharides as adjuvants for DC vaccines, in combination with adoptive immunotherapy and immune checkpoint inhibitors (ICIs), as well as their co-assembly with nanoparticles (NPs) into nano drug delivery systems is also introduced. These results reveal the biological effects of polysaccharides, provide a new perspective for the anti-tumor immunopharmacological research of natural polysaccharides, and provide helpful information for guiding polysaccharides as complementary medicines in cancer immunotherapy.

R-phycocyanin from porphyra haitanensis influences drosophila melanogaster lifespan in a sex-specific manner

Aging has become a major global public health challenge. Our previous research showed that R-phycocyanin (R-PC) possessed anti-aging activity. Notably, studies already revealed that gender may affect the responses to the anti-aging drug. Therefore, it is worth investigating whether the anti-aging effects and their underlying molecular mechanisms of R-PC differ between genders. Firstly, R-PC was isolated from porphyra haitanensis and its anti-aging mechanisms were explored using the nature aging male and female drosophila melanogaster as model. Next, the regulation pathway of longevity was analyzed by KEGG pathway analysis. The longevity pathways-associated molecules were also examined to explore anti-aging mechanisms of R-PC. The results showed that R-PC increased AMPK activity, thus enhanced the key regulatory factors of autophagy (Atg1, Atg8, Atg5), and consequently induced autophagy. Hence, the longevity activity of R-PC life was related with AMPK/mTOR/S6K autophagic signaling pathways in aging female drosophila melanogaster. Meanwhile, R-PC significantly down-regulated TNF-α, MMP3, IL-1β, IL-6, IL-8 expression levels, and the anti-inflammatory and longevity was associated with R-PC-induced regulation of pI3k/AKT/FOXO3 signaling pathway in aging male drosophila melanogaster. These finding showed that R-PC from porphyra haitanensis might exert the anti-aging actions via different mechanisms in male and female drosophila melanogaste.

Sea cucumber chondroitin sulfate polysaccharides attenuate OVA-induced food allergy in BALB/c mice associated with gut microbiota metabolism and Treg cell differentiation

Previous research studies have shown that sulfated polysaccharides can inhibit food allergy, but the detailed mechanism remains largely unknown. In this study, RBL-2H3 cells were used to compare the anti-allergic activities of four sulfated polysaccharides, and an ovalbumin (OVA)-sensitized allergic mouse experiment was used to explore their desensitization effect, with regard to the alteration in gut microbiota and immune cell differentiation. Compared with the shark, bovine and porcine chondroitin sulfate, sea cucumber chondroitin sulfate (SCCS) significantly inhibited the degranulation of RBL-2H3 cells. SCCS reduced allergic symptoms and protected the jejunum from injury in mice. Furthermore, SCCS increased the relative abundance of Lachnospiraceae NK4A136, decreased the relative proportion of Prevotellaceae NK3B31, and up-regulated the secretion of short chain fatty acids such as butyric acid in the feces, resulting in an increase in the mucin 2 (MUC2) secretion by goblet cells HT-29. Meanwhile, SCCS induced the differentiation of regulatory T cells in the mesenteric lymph nodes of mice. This study provides a deeper understanding of the functioning mechanism of SCCS in alleviating food allergy and may guide the development and production of anti-allergy active ingredients.

Porphyra haitanensis Polysaccharides Attenuates Blood Lipid via Gut-Liver Axis in Diet-Induced High-Fat Mesocricetus auratus through Multiple Integrated Omics

SCOPE

Hyperlipidemia is currently a global public health problem severely affecting people's physical and mental health, as well as their quality of life.

METHODS AND RESULTS

The present study is aimed at revealing the mechanism of Porphyra haitanensis polysaccharide (PHP) in decreasing blood lipids by acting through gut-liver axis in Mesocricetus auratus fed a high-fat diet. PHP significantly prevented increases in serum total cholesterol, triglycerides and low-density lipoprotein cholesterol, and alleviated damage to liver cells induced by a high-fat diet M. auratus, in a dose-dependent manner. PHP promotes proliferation of Muribaculaceae and Faecalibaculum, thereby enhancing the production of butyric acid both in the colon and liver, particularly high-dose PHP (HPHP). Low-dose PHP (LPHP) promotes the expression of phosphatidylcholine metabolites and fatty acid transport genes, and inhibits the expression of genes involved in fat degradation (Abhd5), adipogenesis (Me1), fatty acid synthesis (Fasn and Pnpla3), and fatty acid chain elongation (Elovl6) in the liver. However, HPHP inhibits the expression of triglyceride metabolites and promotes the expression of fatty acid transporter (CD36), fatty acid oxidation (Acacb), and peroxisome proliferator-activated receptor gamma (PPARg) genes in the liver.

CONCLUSION

PHP regulates lipid metabolism through the gut microbiota, and the gut-liver axis plays an important role in its hypolipidemic effects.

Methyldecanoate isolated from marine algae Turbinaria ornata enhances immunomodulation in LPS-induced inflammatory reactions in RAW 264.7 macrophages via iNOS/NFκB pathway

This study identifies the anti-inflammatory, antioxidant, and immunomodulatory potential of a fatty acid methyl ester segregated from the brown algae Turbinaria ornata and identified by nuclear magnetic resonance and mass spectrometry as methyl 6,12-dimethyltridecanoate (ET). Antioxidant and anti-inflammatory effects of ET were studied on lipopolysaccharide (LPS)-induced inflammatory reaction in RAW 264.7 macrophages. Moreover, in silico docking studies of isolated ET with inflammatory markers TNFα, NFκB, and COX-2 showed potent binding scores suggesting anti-inflammatory potential. ET significantly reduced LPO and increased LPS-induced SOD, catalase, and GSH levels. Molecular docking results were further confirmed by checking mRNA levels of selected cytokines (IL6 and IL10), followed by protein expression of iNOS and NFκB in LPS-induced macrophages. ET significantly upregulated the expression of IL10 and downregulated the expression of IL6, iNOS, and NFκB, confirming the inhibition of LPS-induced inflammation via the iNOS/NFκB pathway.

Effects of Sparassis latifolia neutral polysaccharide on immune activity via TLR4-mediated MyD88-dependent and independent signaling pathways in RAW264.7 macrophages

Background

Sparassis latifolia (S. latifolia) is a precious edible fungus with multiple biological activities. To date, no study has been investigated the underlying molecular mechanism of immunoregulation caused by the neutral polysaccharide of S. latifolia.

Materials and methods

To investigate immunomodulatory mechanism of S. latifolia neutral polysaccharide (SLNP), SLNP was obtained from S. latifolia and its structure, immune receptors and regulation mechanism were studied.

Results

S. latifolia neutral polysaccharide consisted of arabinose, galactose, glucose, xylose, and mannose with a molar ratio of 6:12:63:10:5. SLNP was a pyran polysaccharide with a relative molecular weight of 3.2 × 105 Da. SLNP promoted the proliferation of RAW264.7, which further induced the secretions of nitric oxide, TNF-α, IL-6, and IFN-β, and upregulated the immune receptor TLR4 expression. Moreover, SLNP increased remarkably the levels of TRAF6, IRF3, JNK, ERK, p38, and p38 mRNA and protein mediated by TLR4.

Conclusion

S. latifolia neutral polysaccharide regulated the immune function of RAW264.7 through MyD88-dependent and -independent signaling pathways mediated by TLR4 receptor, which suggests that SLNP is a new immunomodulator.

Effect of the harvest period on the structure and anti-allergic activity of Porphyra haitanensis polysaccharides

Polysaccharides are a major functional component of seaweeds with various biological activities. Porphyra haitanensis is usually harvested in different growth periods, but how the harvest periods influence the Porphyra haitanensis polysaccharide (PHP) activity is unclear. This work aimed to evaluate the anti-allergic activity of PHP from different harvest periods and investigate the potential structure-activity relationship. The water-soluble polysaccharide of P. haitanensis from three different harvest periods was purified and administered to an ovalbumin-sensitized food allergy mouse model. Results showed that PHPs significantly alleviated the allergic symptoms and reduced the production of histamine and allergen-specific IgE. Further experiments elucidated that PHPs suppressed the allergic activity of intestinal epithelial cells, dendritic cells, and Th2 cells and downregulated the proportion of Th2 cells. Noticeably, the molecular weight and sulfate content gradually decreased as the harvest period was delayed; simultaneously, the anti-allergic activity gradually increased, implying a relationship between the harvest period, structure, and anti-allergic activity of PHPs. This work elucidated the anti-allergic activity of PHPs from different harvest periods, facilitated the deep-processing and efficient application of Porphyra haitanensis, and shed light on the development of novel anti-allergic functional foods.

Anti-Aging Effects of R-Phycocyanin from Porphyra haitanensis on HUVEC Cells and Drosophila melanogaster

Aging has become a global public health challenge. Many studies have revealed that the excessive generation of ROS and oxidative stress could be the major causative factors contributing to aging. In this study, R-phycocyanin (R-PC) was isolated from Porphyra haitanensis, and its anti-aging ability was explored by natural aging Drosophila melanogaster and H₂O₂-induced HUVEC cells as the aging model. Results showed that R-PC α and β subunits expressed have antioxidant activity and can inhibit the generation of radicals, exhibiting a protective effect against H₂O₂-induced apoptotic HUVEC cells death. R-PC prevented the H₂O₂-induced HUVEC cell cycle phase arrest by regulating cell cycle-related protein. Furthermore, R-PC prevented the H₂O₂-induced HUVEC cell cycle phase arrest by regulating cell-cycle-related protein expression. In vivo study also indicated that R-PC significantly increased the survival time and alleviated the oxidative stress of Drosophila melanogaster. Moreover, R-PC notably decreased levels of ROS in natural aging flies and inhibited lipid peroxidation by enhancing the expressions of the endogenous stress marker genes (SOD1, SOD2, CAT of Drosophila melanogaster). Taken together, a study on the antioxidation extract from Porphyra haitanensis, such as R-PC, may open a new window for the prevention of anti-aging.

Porphyra tenera Protects against PM2.5-Induced Cognitive Dysfunction with the Regulation of Gut Function

To evaluate the biological effects of Porphyra tenera (P. tenera), we tried to confirm the possibility that the intake of P. tenera could modulate cognitive and intestinal functions in PM_2.5-induced cognitive decline mice. P. tenera attenuated PM_2.5-induced learning and memory impairment through antioxidant and anti-inflammatory effects by regulating the mitochondrial function and TLR-initiated NF-κB signaling. In addition, P. tenera effectively alleviated Aβ production/tau phosphorylation by inhibiting the JNK phosphorylation. Also, the bioactive constituents of P. tenera determined the sulfated galactan, mycosporine-like amino acids (MAAs), and chlorophyll derivatives. Moreover, the bioactive compounds of P. tenera by gut fermentation protected against gut dysbiosis and intestinal tight junction damage with a decrease in inflammatory response and short-chain fatty acid production. Based on these results, our findings suggest that P. tenera with sulfated galactan and MAAs is a potential material for cognitive function improvement.

Structural characterization and immunoregulatory activity of a novel acidic polysaccharide from Scapharca subcrenata

A novel acidic polysaccharide named SSPA50-1 was isolated from Scapharca subcrenata using a simulated gastric fluid extraction method. SSPA50-1 is a heteropolysaccharide with an average molecular weight of 44.7 kDa that is composed of galacturonic acid, glucose, galactose, mannose, ribose, rhamnose, fucose, xylose and arabinose at a molar ratio of 1.00:5.40:9.04:3.10:1.59:4.01:2.10:2.21:2.28. The structural characterization based on the methylation and 1D/2D NMR analyses indicated that SSPA50-1 is composed of →3)-β-L-Rhap-(1→, →3)-β-L-2-O-Me-Fucp-(1→, →2)-α-D-Xylp-(1→, →5)-α-L-Araf-(1→, →3)-β-D-Galp-(1→, →6)-α-D-Glcp-(1→, →3,4)-β-D-Manp-(1→, →3,4)-β-D-Galp-(1→, β-D-Ribf-(1→, α-D-Glcp-(1→, and α-D-GalAp6Me-(1→. Furthermore, SSPA50-1 possessed potent immunoregulatory activity by enhancing the phagocytosis and NO, iNOS, TNF-α and IL-6 secretion capacity of RAW264.7 cells. Otherwise, SSPA50-1 significantly promoted the proliferation of splenic lymphocytes and RAW264.7 macrophages. These results indicated that SSPA50-1 could be developed as a potential ingredient for immunostimulatory agents.

Relationship Between the Structure and Immune Activity of Components From the Active Polysaccharides APS-II of Astragali Radix by Enzymolysis of Endo α-1,4-Glucanase

Astragali Radix polysaccharides (APSs) have a wide range of biological activities. Our preliminary experiment showed that APS-Ⅱ (10 kDa) was the main immunologically active component of APSs. However, the characteristic structure related to activity of APS-Ⅱ needs further verification and clarification. In this study, APS-II was degraded by endo α-1,4-glucosidase. The degraded products with different degrees of polymerization [1–3 (P1), 3–6 (P2), 7–14 (P3), and 10–18 (P4)] were obtained using a polyacrylamide gel chromatography column. The structural features of the different products were characterized by HPGPC, monosaccharide composition, Fourier transform infrared spectrum, GC–MS, nuclear magnetic resonance, and UPLC-ESI-QTOF-MS analysis. Specific immune and non-specific immune cell tests were used to identify the most immunogenic fractions of the products. The backbone of P4 was speculated to be α-D-1,4-linked glucans and rich in C2 (25.34%) and C6 (34.54%) branches. Immune screening experiments indicated that the activity of P4 was better than that of APS-II and the other three components. In this research, the relationship between the structure of APS-Ⅱ and the immune activity from the degradation level of polysaccharides was studied, laying a foundation for the quality control and product development of APSs.

Structural characteristics and immunomodulatory effects of sulfated polysaccharides derived from marine algae

Marine algae are becoming an important source of valuable candidates of functional food that remain unexplored. Compositional analysis showed that marine algae contain essential nutrients, such as carbohydrates, proteins, fats, and minerals, of which polysaccharides are the main bioactive component. Depending on the source, marine algae polysaccharides are sulfated, which have diverse structures and compositions that influence their biological activities. A growing body of evidence has demonstrated that sulfated polysaccharides derived from marine algae (SPs) exhibit various bioactivities, especially immunomodulation. This review aims at summarizing the structural characteristics of SPs, their immunomodulatory effects, and the structural-immunomodulatory activity relationships between them from articles in recent decade, in order to provide a theoretical basis for the further applications of SPs as promising food or feed additives and possible health products to modulate the immune response.

Advance research in biomedical applications on marine sulfated polysaccharide

Marine ecosystem associated organisms are an affluent source of bioactive compounds. Polysaccharides with unique structural and practical entities have gained special studies interest inside the current biomedical zone. Polysaccharides are the main components of marine algae, plants, animals, insects, and microorganisms. In recent times research on seaweed is more persistent for extraction of natural bioactive "Sulfated polysaccharides" (SPs). The considerable amount of SP exists in the algae in the form of fucans, fucoidans, carrageenans, ulvan, etc. Major function of SPs is to act as a defensive lattice towards the infective organism. All SPs possess the high potential and possess a broad range of therapeutic applications as antitumor, immunomodulatory, vaccine adjuvant, anti-inflammatory, anticoagulant, antiviral, antiprotozoal, antimicrobial, antilipemic, therapy of regenerative medicine, also in drug delivery and tissue engineering application. This review aims to discuss the biomedicine applications of sulfated polysaccharides from marine seaweeds.

Insights on preparation, structure and activities of Gracilaria lemaneiformis polysaccharide

Gracilaria lemaneiformis is a kind of edible economic red algae, which is rich in polysaccharide, phycobiliprotein, pigments, minerals and other nutrients and functional components. Polysaccharide is one of the main active components of Gracilaria lemaneiformis, which has been reported to present various physiological bioactivities, including regulation of glycolipid metabolism, immune, anti-tumor, anti-inflammatory and other biological activities. This paper aims to provide a brief summary of extraction, purification, structural characteristics, and physiological activities of Gracilaria lemaneiformis polysaccharide (GLP). This article is able to provide theoretical basis for the future research and exploitation of GLP, and improve its potential development to promote the healthy and sustainable processing and high value utilization industry of Gracilaria lemaneiformis.

Recent advances in industrial applications of seaweeds

Seaweeds have been generally utilized as food and alternative medicine in different countries. They are specifically used as a raw material for wine, cheese, soup, tea, noodles, etc. In addition, seaweeds are potentially good resources of protein, vitamins, minerals, carbohydrates, essential fatty acids and dietary fiber. The quality and quantity of biologically active compounds in seaweeds depend on season and harvesting period, seaweed geolocation as well as ecological factors. Seaweeds or their extracts have been studied as innovative sources for a variety of bioactive compounds such as polyunsaturated fatty acids, polyphenols, carrageenan, fucoidan, etc. These secondary metabolites have been shown to have antioxidant, antimicrobial, antiviral, anticancer, antidiabetic, anti-inflammatory, anti-aging, anti-obesity and anti-tumour properties. They have been used in pharmaceutical/medicine, and food industries since bioactive compounds from seaweeds are regarded as safe and natural. Therefore, this article provides up-to-date information on the applications of seaweed in different industries such as pharmaceutical, biomedical, cosmetics, dermatology and agriculture. Further studies on innovative extraction methods, safety issue and health-promoting properties should be reconsidered. Moreover, the details of the molecular mechanisms of seaweeds and their bioactive compounds for physiological activities are to be clearly elucidated.

Application of X-ray diffraction and energy dispersive spectroscopy in the isolation of sulfated polysaccharide from Porphyra haitanensis and its antioxidant capacity under in vitro digestion

BACKGROUND

The separation and purification of Porphyra haitanensis polysaccharide (PHP), and the determination of changes in molecular weight (Mw) and antioxidant capacity after in vitro digestion, were undertaken.

RESULTS

Analysis of two polysaccharide fractions (PHP0.5-1-UF and PHP1.0-1-UF) by various techniques showed that they were very pure sulfated polysaccharides without pigment or protein. PHP0.5-1-UF was filamentous or 'tape-like' sheets, whereas PHP1.0-1-UF had some filaments and large numbers of rounded aggregates. The Mw of PHP, PHP0.5-1-UF and PHP1.0-1-UF was 2.06 × 10⁶ (±2.02%), 6.68 × 10⁶ (±3.17%), and 1.14 × 10⁶ (±3.44%) (g mol^-1 ), respectively. After in vitro digestion, the Mw of PHP, PHP0.5-1-UF, and PHP1.0-1-UF decreased. Their antioxidant capacities were markedly higher than before digestion, especially PHP0.5-1-UF and its digestion products, which might be related to the reductions in Mw.

CONCLUSION

These findings provide a greater understanding of the separation and purification of sulfated polysaccharides and the influence of digestion on biological activity. They also contribute to the practical application of sulfated polysaccharides in functional foods. © 2021 Society of Chemical Industry.

Characterization and immunomodulatory activity of sulfated galactan from the red seaweed Gracilaria fisheri

Polysaccharides from the red seaweed Gracilaria fisheri possess many functions, which include antioxidant, antiviral, and antibacterial activities. However, detailed data on their immunomodulatory activities are scarce. Here, we isolated sulfated galactans (SG) from G. fisheri. We found that the predominant SG from G. fisheri, termed SG-1, had an estimated molecular mass of 100 kDa and activated murine J774A.1 macrophages via the dectin-1 signaling pathway. Furthermore, we observed enhancement of nitric oxide (NO) secretion, increased expression of inducible nitric oxide synthase (iNOS) mRNA, and increased mRNA levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukins IL-1β and IL-6 by SG-1 in macrophages. Moreover, there was higher expression of intercellular adhesion molecule 1 (ICAM-1) and co-stimulatory molecules (B7-1 and B7-2) mRNA. Treatment with G. fisheri SG-1 at 50 μg/mL generally achieved or exceeded the pro-inflammatory activities of 100 ng/mL lipopolysaccharide. Our study demonstrates immune-stimulatory activities of G. fisheri SG that may be of value for immune-potentiating treatment in humans or livestock.

Degraded polysaccharides from Porphyra haitanensis: purification, physico-chemical properties, antioxidant and immunomodulatory activities

To explore effect of the structural properties of porphyra haitanensis polysaccharide on its biological activity, degraded porphyra polysaccharides were separated and purified by Cellulose DEAE-52 and Sephadex G-100 chromatography, obtaining three purified components (P1, P2 and P3). All the three components were sulfate polysaccharides containing the repeating units of → 3) β-D-galactose (1 → 4) 3,6-anhydro-α-L-galactose (1 →, and → 3) β-D-galactose (1 → 4) α-L-galactose-6-S (1 →, and → 3) 6-O-methyl-β-D-galactose (1 → 4) 3,6-anhydro-α-L-galactose (1 →. The molecular weight of the three fractions was measured to be 300.3, 130.4 and 115.1 kDa, respectively. Their antioxidant activity was investigated by the determination of the free radical scavenging effect and ferric reducing power. It was found that P1, P2 and P3 possessed marked antioxidant activity. It was also found that they appreciably enhanced the proliferation, phagocytic ability and nitric oxide secretion in RAW264.7 cells. Lower molecular weight and higher sulfate content were beneficial to bioactivities of P. haitanensis polysaccharides. Overall, P2 and P3 possess superior immuno-modulatory activity to that of P1 and PHP. Thus, the current work will provide the basis for the better utilization of P. haitanensis to develop the related functional foods.

Plant/algal polysaccharides extracted by microwave: A review on hypoglycemic, hypolipidemic, prebiotic, and immune-stimulatory effect

Microwave-assisted extraction (MAE) is an emerging technology to obtain polysaccharides with an extensive spectrum of biological characteristics. In this study, the hypoglycemic, hypolipidemic, prebiotic, and immunomodulatory (e.g., antiinflammatory, anticoagulant, and phagocytic) effects of algal- and plant-derived polysaccharides rich in glucose, galactose, and mannose using MAE were comprehensively discussed. The in vitro and in vivo results showed that these bioactive macromolecules with the low digestibility rate could effectively alleviate the fatty acid-induced lipotoxicity, acute hemolysis, and dyslipidemia status. The optimally extracted glucomannan- and glucogalactan-containing polysaccharides revealed significant antidiabetic effects through inhibiting α-amylase and α-glucosidase, improving dynamic insulin sensitivity and secretion, and promoting pancreatic β-cell proliferation. These bioactive macromolecules as prebiotics not only improve the digestibility in gastrointestinal tract but also reduce the survival rate of pathogens and tumor cells by activating macrophages and producing pro-inflammatory biomarkers and cytokines. They can effectively prevent gastrointestinal disorders and microbial infections without any toxicity.

Protective effects of sulfated polysaccharides from Lentinula edodes on the lung and liver of MODS mice

In this work, the effects of sulfated polysaccharides from Lentinula edodes (SPLE) on zymosan (ZYM)-induced multiple organ dysfunction syndrome (MODS) mice were investigated. Using the MODS mice model, biochemical works have already shown that in mice treated with SPLE, the lung parameters of GGT, C3 and hs-CRP were down-regulated and the hepatic parameters of TC, TG, ALT and AST, HDLC, LDL-C and VLDL-C were improved, the serum levels of CK, Cr and Amy were decreased, and the levels of inflammatory factors such as TNF-α, IL-1β, IL-6 and IL-10 were also reduced, the activity of antioxidant enzymes SOD and CAT enhanced, and the content of MDA was reduced. In addition, histopathology of the lung and liver confirmed the beneficial effects of SPLE on MODS mice, indicating that SPLE played a role in protecting the organ function of MODS mice. In addition, SPLE was characterized as a sulfated β-glucan linked by β-type glycosidic bonds. These conclusions indicated that SPLE had effective antioxidant and anti-inflammatory activities, and could be used as a functional food and medicine to prevent MODS.

Marine algal antagonists targeting 3CL protease and spike glycoprotein of SARS-CoV-2: a computational approach for anti-COVID-19 drug discovery

The COVID-19 pandemic has severely destructed human life worldwide, with no suitable treatment until now. SARS-CoV-2 virus is unprecedented, resistance against number of therapeutics and spreading rapidly with high mortality, which warrants the need to discover new effective drugs to combat this situation. This current study is undertaken to explore the antiviral potential of marine algal compounds to inhibit the viral entry and its multiplication using computational analysis. Among the proven drug discovery targets of SARS-CoV-2, spike glycoprotein and 3-chymotrypsin-like protease are responsible for the virus attachment and viral genome replication in the host cell. In this study, the above-mentioned drug targets were docked with marine algal compounds (sulfated polysaccharides, polysaccharide derivatives and polyphenols) using molecular docking tools (AutoDockTools). The obtained results indicate that κ-carrageenan, laminarin, eckol, trifucol and β-D-galactose are the top-ranking compounds showing better docking scores with SARS-CoV-2 targets, than the current experimental COVID-19 antiviral drugs like dexamethasone, remdesivir, favipiravir and MIV-150. Further, molecular dynamic simulation, ADMET and density functional theory calculations were evaluated to substantiate the findings. To the best of our knowledge, this is the first report on in silico analysis of aforesaid algal metabolites against SARS-CoV-2 targets. This study concludes that these metabolites can be curative for COVID-19 in the hour of need after further validations in in vitro and in vivo testings.Communicated by Ramaswamy H. Sarma.

Degraded Porphyra haitanensis sulfated polysaccharide relieves ovalbumin-induced food allergic response by restoring the balance of T helper cell differentiation

We previously described that Porphyra haitanensis sulfated polysaccharide (PHSP) maintains the balance of pro-inflammation and immunosuppression. However, it is unclear whether degraded PHSP (DPHSP) still shows the immunomodulatory activity. Here, we degraded PHSP by four different methods alone or combined in pairs, and the results showed that the molecular weight and viscosity of DPHSP were significantly decreased, while the main chemical bonds and functional structure were consistent with those of PHSP. We then investigated the immunomodulatory function of DPHSP in vitro and in vivo. Actually, DPHSP enhances the inhibitory effects on mast cell activation and improves the suppression activity of PHSP on the food anaphylactic response. In an ovalbumin-induced food allergy mouse model, the production of allergic mediators and cytokines (interleukin-4 and 13, and interferon-γ) was inhibited by DPHSP. Meanwhile, DPHSP had a stronger ability to up-regulate the differentiation of regulatory T (Treg) cells and its related cytokines. These results suggested that DPHSP showed a better anti-food allergic ability than PHSP by regulating T helper cell balance and promoting Treg cell differentiation, which indicates that DPHSP is a novel potential nutrient component against food allergy.

Transcriptome Analysis Reveals Possible Immunomodulatory Activity Mechanism of Chlorella sp. Exopolysaccharides on RAW264.7 Macrophages

In this study, the exopolysaccharides of Chlorella sp. (CEP) were isolated to obtain the purified fraction CEP4. Characterization results showed that CEP4 was a sulfated heteropolysaccharide. The main monosaccharide components of CEP4 are glucosamine hydrochloride (40.8%) and glucuronic acid (21.0%). The impact of CEP4 on the immune activity of RAW264.7 macrophage cytokines was detected, and the results showed that CEP4 induced the production of nitric oxide (NO), TNF-α, and IL-6 in a dose-dependent pattern within a range of 6 μg/mL. A total of 4824 differentially expressed genes (DEGs) were obtained from the results of RNA-seq. Gene enrichment analysis showed that immune-related genes such as NFKB1, IL-6, and IL-1β were significantly upregulated, while the genes RIPK1 and TLR4 were significantly downregulated. KEGG pathway enrichment analysis showed that DEGs were significantly enriched in immune-related biological processes, including toll-like receptor (TLR) signaling pathway, cytosolic DNA-sensing pathway, and C-type lectin receptor signaling pathway. Protein–protein interaction (PPI) network analysis showed that HSP90AB1, Rbx1, ISG15, Psmb6, Psmb3, Psmb8, PSMA7, Polr2f, Rpsa, and NEDD8 were the hub genes with an essential role in the immune activity of CEP4. The preliminary results of the present study revealed the potential mechanism of CEP4 in the immune regulation of RAW264.7 macrophages, suggesting that CEP4 is a promising immunoregulatory agent.

The immunomodulatory effects of Carapax Trionycis ultrafine powder on cyclophosphamide-induced immunosuppression in Balb/c mice

BACKGROUND

There are abundant resources of Carapax Trionycis from soft-shelled turtle processing wastes each year in China. Our preliminary work showed that Carapax Trionycis ultrafine powder (CTUP) obtained using ball-milling with a particle size of 2.24 μm (D0.025) contained more active ingredients. The CTUP D0.025 has a good bioaccessibility, but there has been no report about the immunomodulatory function of CTUP. Therefore, using a cyclophosphamide-induced immunosuppression mice model, we investigated the immunomodulatory effects of CTUP D0.025.

RESULTS

The results indicated that CTUP D0.025 administration significantly improved the immune organ (bone marrow, thymus and spleen) indices, ameliorated spleen tissue morphology and increased the capacity of splenocyte proliferation and the activity of macrophage phagocytosis. CTUP D0.025 also significantly promoted the secretion of cytokines (IL-2, IL-4, IL-10, IFN-γ and TNF-α), improved the related mRNA expression levels of IL2, IFN-γ, T-bet and GATA3 in immunosuppressed mice and increased the production of serum hemolysin and the levels of IgG, IgM as well as complement C₃ . Moreover, CTUP D0.025 administration enhanced the antioxidant capacity of mice, exhibited a moderating effect on the damage of bone and skeletal muscle and improved the recovery of bone mineral density and calcium metabolism.

CONCLUSIONS

These findings demonstrated that CTUP D0.025 had an effective immune-enhancing function in immunosuppressive Balb/c mice and also exhibited anti-osteoporosis properties. © 2020 Society of Chemical Industry.

Purification and Biological Activities of Enzymatically Degraded Sargassum fusiforme Polysaccharides

Enzymatic hydrolysate of the crude polysaccharide (SFP) extracted from Sargassum fusiforme was purified by column DEAE-52 and Sephadex G-100 to yield four components, namely, ESFP1, ESFP2, ESFP3 and ESFP4. These components were characterized by chemical composition assay, GC/MS, HPGPC, UV and FT-IR techniques. The in vitro antioxidant activities of the four purified fractions were investigated by measuring their radical scavenging activity and reducing power. The results suggested that all the four components possess good antioxidant activities. Among them, ESFP1 was found to possess the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical-scavenging activity, and the greatest ferric reducing power. The immunomodulatory effect of these four polysaccharides was demonstrated by their ability to promote proliferation, and to enhance both phagocytic activity and NO release in a macrophage RAW264.7 model. The results revealed that the bioactivities of the polysaccharides are related to their molecular weight, and the uronic acid and sulfate contents.

Purification, structural characterization, and biological activities of degraded polysaccharides from Porphyra yezoensis

The degraded polysaccharides from Porphyra yezoensis (DPPY) prepared using the H₂ O₂ -Vc method under optimized conditions were isolated and purified by DEAE Cellulose-52, and Sephadex G-100, providing four pure components, namely, DPPY-0, DPPY-0.1, DPPY-0.3, and DPPY-0.5. Their relative molecular weights were measured to be 10.8, 10.7, 18.7, and 35.5 kDa, respectively. GC-MS analysis revealed that all the four fractions were mainly composed of galactose, together with a small portion of glucose, mannose, xylose, and rhamnose. Structural analysis revealed that the purified polysaccharides mainly possess a backbone of (1 → 3)-β-D-galactose (1 → 4)-3,6-anhydro-α-L-galactopyranose (G-A) units and (1 → 3)-β-D-galactose (1 → 4)-α-L-galactose-6-sulfate (G-L6S) units. They were found to promote the proliferation of RAW264.7 macrophages and enhance phagocytosis of the RAW264.7 cells. Antioxidant assays indicated that DPPY-0.5 possessed the most potent reducing power and free radical scavenging ability among the four purified polysaccharides. High sulfate content and proper molecular weight of these fractions are favorable to their immunomodulatory and antioxidant activities. PRACTICAL APPLICATIONS: Porphyra yezoensis, common economic red algae widely distributed in East Asian countries, contains a high content of polysaccharides with a variety of biological activities. However, P. yezoensis polysaccharide (PPY) has not been well utilized due to the relatively low biological activities and lack of understanding of its structure-activity relationship. Thus, it is necessary to improve the bioactivities and elucidate the structure-activity relationship of this polysaccharide for its practical use. In the present work, four purified fractions (DPPY-0, DPPY-0.1, DPPY-0.3, and DPPY-0.5) were isolated from the degraded P. yezoensis polysaccharide, and were investigated for their antioxidant and immunoregulatory activities. The results of the present work will lay a foundation for the application of the degraded P. yezoensis polysaccharide in the food industry as a functional food ingredient.

Immunomodulatory activity of puerarin in RAW264.7 macrophages and cyclophosphamide-induced immunosuppression mice

CONTEXT

Puerarin, a natural isoflavone extracted from Radix puerariae, is famous for treating various cardiovascular and cerebrovascular diseases. However, little is known about its direct immunomodulatory activity.

OBJECTIVE

This study was designed to investigate the in vitro and in vivo immunomodulatory effects of Radix puerariae by using the murine monocyte-macrophage cell line RAW264.7 and immunosuppressed cyclophosphamide-induced mice.

METHODS

MTT and neutral red phagocytosis assays were conducted to evaluate the in vitro immunomodulatory activities of puerarin on cell viability and phagocytosis by measuring the proliferation, phagocytic, nitric oxide (NO) ability, and TNF-α production ability of stimulated and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Immunosuppressed cyclophosphamide-induced mice were used to evaluate the in vivo immunomodulatory activities of puerarin by measuring IL-4 and IFN-γ, the serum half hemolysis value, spleen and thymus index, and proliferation assay for splenic lymphocytes.

RESULTS AND DISCUSSION

Results showed that puerarin improves immunomodulatory activity by increasing cell proliferation, cell phagocytosis, and NO secretion in RAW264.7 macrophages and reduces the abnormal immunologic activity by decreasing cell phagocytosis and NO secretion in LPS-stimulated RAW264.7 macrophages. In addition, puerarin enhanced the immunologic activity of cyclophosphamide-induced immunosuppression mice by increasing the secretion of NO, IFN-γ, and IL-4, the serum half hemolysis value (HC₅₀), the spleen and thymus index, and proliferation for splenic lymphocytes.

CONCLUSION

Puerarin exhibited an upregulated immunomodulatory effect on RAW264.7 macrophages and immunosuppression mice. In addition, puerarin had a downregulated immunomodulatory effect on RAW264.7 macrophages. The results suggest that puerarin could be a promising immunomodulator to assist in the treatment of tumors.

Invasive Seaweeds in the Iberian Peninsula: A Contribution for Food Supply

The introduction of exotic organisms in marine ecosystems can lead to economic and ecological losses. Globally, seaweeds represent a significant part of these non-indigenous species (NIS), with 407 introduced algal species. Furthermore, the presence of NIS seaweeds has been reported as a major concern worldwide since the patterns of their potential invasion mechanisms and vectors are not yet fully understood. Currently, in the Iberian Peninsula, around 50 NIS seaweeds have been recorded. Some of these are also considered invasive due to their overgrowth characteristic and competition with other species. However, invasive seaweeds are suitable for industrial applications due to their high feedstock. Hence, seaweeds' historical use in daily food diet, allied to research findings, showed that macroalgae are a source of nutrients and bioactive compounds with nutraceutical properties. The main goal of this review is to evaluate the records of NIS seaweeds in the Iberian Peninsula and critically analyze the potential of invasive seaweeds application in the food industry.

Sulfated modification, characterization, immunomodulatory activities and mechanism of the polysaccharides from Cyclocarya paliurus on dendritic cells

In this study, a crude and purified polysaccharide from Cyclocarya paliurus (CPP, CPP_0.05) were performed with chlorosulfonic acid-pyridine (CSA-Pyr) method to obtain sulfated derivatives (S-CPP, S-CPP_0.05). After comparatively investigating, characterization results showed that the modifications were successful. Polysaccharides were used to culture mouse bone marrow-derived dendritic cells (BM-DCs) to evaluate their immunomodulatory activity and explore mechanism. The functional activity of CPP was significantly stronger than that of the purified polysaccharide CPP_0.05. Meanwhile, S-CPP showed stronger immunomodulatory activity than CPP through determination of cytokine expression levels. We found that p-JNK, p-p38MAPK and NF-κB p65 proteins were significantly increased by stimulus of CPP and S-CPP, blocking TLR2/4 could significantly decreased proteins above which proved that immune regulation effect of CPP and S-CPP on DCs was performed via MAPK and NF-κB signaling pathways by triggering TLR2/4. S-CPP could serve as potential immunomodulatory agents used as complementary medicine or functional foods.

The Evolution Road of Seaweed Aquaculture: Cultivation Technologies and the Industry 4.0

Seaweeds (marine macroalgae) are autotrophic organisms capable of producing many compounds of interest. For a long time, seaweeds have been seen as a great nutritional resource, primarily in Asian countries to later gain importance in Europe and South America, as well as in North America and Australia. It has been reported that edible seaweeds are rich in proteins, lipids and dietary fibers. Moreover, they have plenty of bioactive molecules that can be applied in nutraceutical, pharmaceutical and cosmetic areas. There are historical registers of harvest and cultivation of seaweeds but with the increment of the studies of seaweeds and their valuable compounds, their aquaculture has increased. The methodology of cultivation varies from onshore to offshore. Seaweeds can also be part of integrated multi-trophic aquaculture (IMTA), which has great opportunities but is also very challenging to the farmers. This multidisciplinary field applied to the seaweed aquaculture is very promising to improve the methods and techniques; this area is developed under the denominated industry 4.0.

The Comparative Immunotropic Activity of Carrageenan, Chitosan and Their Complexes

The immunotropic activity of polyelectrolyte complexes (PEC) of κ-carrageenan (κ-CGN) and chitosan (CH) of various compositions was assessed in comparison with the initial polysaccharides in comparable doses. For this, two soluble forms of PEC, with an excess of CH (CH:CGN mass ratios of 10:1) and with an excess of CGN (CH: CGN mass ratios of 1:10) were prepared. The ability of PEC to scavenge NO depended on the content of the κ-CGN in the PEC. The ability of the PEC to induce the synthesis of pro-inflammatory (tumor necrosis factor-α (TNF-α)) and anti-inflammatory (interleukine-10 (IL-10)) cytokines in peripheral blood mononuclear cell was determined by the activity of the initial κ-CGN, regardless of their composition. The anti-inflammatory activity of PEC and the initial compounds was studied using test of histamine-, concanavalin A-, and sheep erythrocyte immunization-induced inflammation in mice. The highest activity of PEC, as well as the initial polysaccharides κ-CGN and CH, was observed in a histamine-induced exudative inflammation, directly related to the activation of phagocytic cells, i.e., macrophages and neutrophils.

Anti-cancer effects of Porphyra haitanensis polysaccharides on human colon cancer cells via cell cycle arrest and apoptosis without causing adverse effects in vitro

In this study, the anticancer effects of Porphyra haitanensis polysaccharides (PHPs) on human colon cancer cells and non-cancerous cells were evaluated. PHP was extracted by an ultrasonic/microwave-assisted method, and three fractions of polysaccharides (PHP-F1, PHP-F2 and PHP-F3) were obtained through a DEAE-52 cellulose ion-exchange column. The results of the cytotoxicity test showed that all of the PHP fractions had inhibitory effects on the growth of colon cancer cells HT-29, LoVo and SW-480, but no toxic effects on the normal human cells HaCaT. The fractions PHP-F2 and PHP-F3 had the most significant cytotoxicity on HT-29 cells. Studies on intracellular reactive oxygen species (ROS) levels, cell apoptosis, the apoptosis index (using Hoechst 33342 staining) and analysis of cell cycle arrest using flow cytometry revealed that the fractions PHP-F2 and PHP-F3 could apparently induce oxidative stress and apoptosis in HT-29 cells and cause cell G0-G1 phase arrest. These findings suggest that polysaccharides from P. haitanensis have anticancer effects on human colon cancer cells and therefore might be regarded as new candidates for the prevention and treatment of colon cancers.