The Protective and Immunomodulatory Effects of Fucoidan Against 7,12-Dimethyl benz[a]anthracene-Induced Experimental Mammary Carcinogenesis Through the PD1/PDL1 Signaling Pathway in Rats

Steady-State Delivery and Chemical Modification of Food Nutrients to Improve Cancer Intervention Ability

Cancer is a crucial global health problem, and prevention is an important strategy to reduce the burden of the disease. Daily diet is the key modifiable risk factor for cancer, and an increasing body of evidence suggests that specific nutrients in foods may have a preventive effect against cancer. This review summarizes the current evidence on the role of nutrients from foods in cancer intervention. It discusses the potential mechanisms of action of various dietary components, including phytochemicals, vitamins, minerals, and fiber. The findings of epidemiological and clinical studies on their association with cancer risk are highlighted. The foods are rich in bioactive compounds such as carotenoids, flavonoids, and ω-3 fatty acids, which have been proven to have anticancer properties. The effects of steady-state delivery and chemical modification of these food's bioactive components on anticancer and intervention are summarized. Future research should focus on identifying the specific bioactive compounds in foods responsible for their intervention effects and exploring the potential synergistic effects of combining different nutrients in foods. Dietary interventions that incorporate multiple nutrients and whole foods may hold promise for reducing the risk of cancer and improving overall health.

Low molecular weight fucoidan LF2 improves the immunosuppressive tumor microenvironment and enhances the anti-pancreatic cancer activity of oxaliplatin

Chemotherapy remains the cornerstone of pancreatic cancer treatment. However, the dense interstitial and immunosuppressive microenvironment frequently render the ineffective anti-tumor activity of chemotherapeutic agents. Macrophages play a key role in the tumor immunomodulation. In this study, we found that low molecular weight of fucoidan (LF2) directly regulated the differentiation of mononuclear macrophages into the CD86+ M1 phenotype. LF2 significantly upregulated the expressions of M1 macrophage-specific cytokines, including iNOS, IL-6, TNFα and IL-12. LF2 modulated macrophage phenotypic transformation through activation of TLR4-NFκB pathway. Furthermore, we observed that LF2 enhanced the pro-apoptotic activity of oxaliplatin (OXA) in vitro by converting macrophages to a tumoricidal M1 phenotype. Meanwhile, LF2 increased intratumoral M1 macrophage infiltration and ameliorated the immunosuppressed tumor microenvironment, which in turn enhanced the anti-pancreatic ductal adenocarcinoma (PDAC) activity of OXA in vivo. Taken together, our results suggested that LF2 could act as a TLR4 agonist targeting macrophages and has a synergistic effect against PDAC when combined with OXA.

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.

Novel Fucoidan Pharmaceutical Formulations and Their Potential Application in Oncology-A Review

Fucoidan belongs to the family of marine sulfated, L-fucose-rich polysaccharides found in the cell wall matrix of various brown algae species. In the last few years, sulfated polysaccharides have attracted the attention of researchers due to their broad biological activities such as anticoagulant, antithrombotic, antidiabetic, immunomodulatory, anticancer and antiproliferative effects. Recently the application of fucoidan in the field of pharmaceutical technology has been widely investigated. Due to its low toxicity, biocompatibility and biodegradability, fucoidan plays an important role as a drug carrier for the formulation of various drug delivery systems, especially as a biopolymer with anticancer activity, used for targeted delivery of chemotherapeutics in oncology. Furthermore, the presence of sulfate residues with negative charge in its structure enables fucoidan to form ionic complexes with oppositely charged molecules, providing relatively easy structure-forming properties in combination with other polymers. The aim of the present study was to overview essential fucoidan characteristics, related to its application in the development of pharmaceutical formulations as a single drug carrier or in combinations with other polymers. Special focus was placed on micro- and nanosized drug delivery systems with polysaccharides and their application in the field of oncology.

Polysaccharides-Naturally Occurring Immune Modulators

The prevention of disease and infection requires immune systems that operate effectively. This is accomplished by the elimination of infections and abnormal cells. Immune or biological therapy treats disease by either stimulating or inhibiting the immune system, dependent upon the circumstances. In plants, animals, and microbes, polysaccharides are abundant biomacromolecules. Due to the intricacy of their structure, polysaccharides may interact with and impact the immune response; hence, they play a crucial role in the treatment of several human illnesses. There is an urgent need for the identification of natural biomolecules that may prevent infection and treat chronic disease. This article addresses some of the naturally occurring polysaccharides of known therapeutic potential that have already been identified. This article also discusses extraction methods and immunological modulatory capabilities.

Anti-Proliferative and Pro-Apoptotic vLMW Fucoidan Formulas Decrease PD-L1 Surface Expression in EBV Latency III and DLBCL Tumoral B-Cells by Decreasing Actin Network

Epstein-Barr virus (EBV) infects 95% of the world's population and persists latently in the body. It immortalizes B-cells and is associated with lymphomas. LCLs (lymphoblastoid cell lines, EBV latency III B-cells) inhibit anti-tumoral T-cell response following PD-L1 overexpression (programmed death-ligand 1 immune checkpoint). Many cancer cells, including some DLBCLs (diffuse large B-cell lymphomas), also overexpress PD-L1. Immunotherapies are based on inhibition of PD-L1/PD-1 interactions but present some dose-dependent toxicities. We aim to find new strategies to improve their efficiency by decreasing PD-L1 expression. Fucoidan, a polysaccharide extracted from brown seaweed, exhibits immunomodulatory and anti-tumor activities depending on its polymerization degree, but data are scarce on lymphoma cells or immune checkpoints. LCLs and DLBCLs cells were treated with native fucoidan (Fucus vesiculosus) or original very-low-molecular-weight fucoidan formulas (vLMW-F). We observed cell proliferation decrease and apoptosis induction increase with vLMW-F and no toxicity on normal B- and T-cells. We highlighted a decrease in transcriptional and PD-L1 surface expression, even more efficient for vLMW than native fucoidan. This can be explained by actin network alteration, suggesting lower fusion of secretory vesicles carrying PD-L1 with the plasma membrane. We propose vLMW-F as potential adjuvants to immunotherapy due to their anti-proliferative and proapoptotic effects and ability to decrease PD-L1 membrane expression.

Fucoidan-based nanomaterial and its multifunctional role for pharmaceutical and biomedical applications

Fucoidans are promising sulfated polysaccharides isolated from marine sources that have piqued the interest of scientists in recent years due to their widespread use as a bioactive substance. Bioactive coatings and films, unsurprisingly, have seized these substances to create novel, culinary, therapeutic, and diagnostic bioactive nanomaterials. The applications of fucoidan and its composite nanomaterials have a wide variety of food as well as pharmacological properties, including anti-oxidative, anti-inflammatory, anti-cancer, anti-thrombic, anti-coagulant, immunoregulatory, and anti-viral properties. Blends of fucoidan with other biopolymers such as chitosan, alginate, curdlan, starch, etc., have shown promising coating and film-forming capabilities. A blending of biopolymers is a recommended approach to improve their anticipated properties. This review focuses on the fundamental knowledge and current development of fucoidan, fucoidan-based composite material for bioactive coatings and films, and their biological properties. In this article, fucoidan-based edible bioactive coatings and films expressed excellent mechanical strength that can prolong the shelf-life of food products and maintain their biodegradability. Additionally, these coatings and films showed numerous applications in the biomedical field and contribute to the economy. We hope this review can deliver the theoretical basis for the development of fucoidan-based bioactive material and films.

Brown Seaweed Food Supplementation: Effects on Allergy and Inflammation and Its Consequences

Multiple health benefits have been ascribed to brown seaweeds that are used traditionally as dietary component mostly in Asia. This systematic review summarizes information on the impact of brown seaweeds or components on inflammation, and inflammation-related pathologies, such as allergies, diabetes mellitus and obesity. We focus on oral supplementation thus intending the use of brown seaweeds as food additives. Despite the great diversity of experimental systems in which distinct species and compounds were tested for their effects on inflammation and immunity, a remarkably homogeneous picture arises. The predominant effects of consumption of brown seaweeds or compounds can be classified into three categories: (1) inhibition of reactive oxygen species, known to be important drivers of inflammation; (2) regulation, i.e., in most cases inhibition of proinflammatory NF-κB signaling; (3) modulation of adaptive immune responses, in particular by interfering with T-helper cell polarization. Over the last decades, several inflammation-related diseases have increased substantially. These include allergies and autoimmune diseases as well as morbidities associated with lifestyle and aging. In this light, further development of brown seaweeds and seaweed compounds as functional foods and nutriceuticals might contribute to combat these challenges.

Polysaccharides with Antitumor Effect in Breast Cancer: A Systematic Review of Non-Clinical Studies

Purpose: To review the effects of polysaccharides and their proposed mechanisms of action in breast cancer experimental models. Data sources, selection, and extraction: Articles were selected by using PubMed, ScienceDirect, Scopus, and Medline, assessed from 1 May 2019 to 1 July 2020. The systematic review was registered in the International Prospective Register of Systematic Reviews (Prospero) under the number CRD42020169103. Results: Most of the studies explore algae polysaccharides (43.2%), followed by mushrooms (13.5%), plants (13.5%), fruits (10.8%), fungus (2.7%), bacteria, (2.7%), and sea animals (2.7%). A total of 8.1% investigated only in vitro models, 62.1% evaluated only in vivo models, and 29.7% evaluated in vitro and in vivo models. The mechanism of action involves apoptosis, inhibition of cellular proliferation, angiogenesis, and antimetastatic effects through multiple pathways. Conclusions: Findings included here support further investigations on the anti-tumor effect of polysaccharides. Some polysaccharides, such as fucoidan and β-glucans, deserve detailed and structured studies aiming at translational research on breast tumors, since they are already used in the clinical practice of other proposals of human health.

Expression of CD27 and CD28 on γδ T cells from the peripheral blood of patients with allergic rhinitis

The costimulatory receptors CD27 and CD28 have pivotal and non-redundant roles in the activation and differentiation of γδ T-cells. However, the roles of CD27 and CD28 on γδ T-cells in allergic rhinitis (AR) have remained elusive. The aim of the present study was to investigate the expression of CD27 and CD28 on γδ T cells in patients with AR. Peripheral blood mononuclear cells from 14 patients with AR and 12 healthy subjects were isolated and analyzed by flow cytometry to determine the percentage of γδ T cells and regulatory T cells (Tregs), and the expression of IFN-γ, IL-17A, CD27 and CD28 on γδ T cells. The correlations between the expression of CD27 and CD28, and the percentages of IFN-γ⁺ and IL-17A⁺ γδ T-cell subsets and Tregs in AR were analyzed. It was observed that the percentages of γδ T cells, and the IL-17A⁺, CD27^-CD28⁺ and CD27^-CD28^- γδ T-cell subsets were significantly increased, while the percentages of Tregs and IFN-γ⁺ and CD27⁺CD28⁺ γδ T-cell subsets were significantly decreased in AR. Of note, the percentage of CD27⁺CD28⁺ γδ T-cell subsets was positively correlated with that of the IFN-γ⁺ γδ T-cell subset and the percentage of the CD27^-CD28⁺ γδ T-cell subset was positively correlated with that of the IL-17A⁺ γδ T-cell subset. Furthermore, the percentages of γδ T cells and the CD27^-CD28⁺ γδ T-cell subset were both negatively correlated with that of Tregs. Therefore, the results of the present study indicate that CD27 and CD28 may be the key signals for activation of different γδ T-cell subsets and may contribute to the immune regulatory function of γδ T cells in the peripheral blood of patients with AR.

Haimufang decoction, a Chinese medicine formula for lung cancer, arrests cell cycle, stimulates apoptosis in NCI-H1975 cells, and induces M1 polarization in RAW 264.7 macrophage cells

BACKGROUND

Lung cancer has the highest morbidity and mortality in the world and novel treatment strategies are still needed. Haimufang decoction (HMF) is a patented clinical prescription of traditional Chinese medicine for lung cancer treatment. HMF is composed of four herbs and has been applied clinically in advanced cancer patients. However, its therapeutic mechanisms are still unclear. This study aims to elucidate the possible mechanisms of HMF for the treatment of lung cancer.

METHODS

3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was applied for evaluating the proliferative effect of HMF in lung cancer cells and monocyte macrophage RAW264.7 cells. Flow cytometer was used to detect the effects of HMF on cell cycle and apoptosis, and western blotting was employed to explore the potential apoptotic mechanisms of HMF on lung cancer cells. For immunomodulatory effect, co-culture system was used to detect the activation of macrophage RAW264.7 cells when treated with HMF, and neutral red assay was used to measure the effect of HMF on the phagocytosis of the activated macrophages. Enzyme linked immunosorbent assay, flow cytometer, and immunofluorescence staining method were employed for the investigation on the underlying mechanisms of the immunomodulatory effect on RAW264.7 induced by HMF.

RESULTS

HMF inhibited the proliferation, induced S phase cell cycle arrest, and stimulated apoptosis in lung cancer NCI-H1975 cells, while had negligible cytotoxicity on macrophage RAW264.7 cells. Moreover, HMF could activate macrophage RAW264.7 cells and promote the inhibition activity of RAW264.7 cells against lung cancer cells. And also, HMF activated macrophages and increased their phagocytic activity in a concentration-dependent manner. HMF increased the expression of macrophage activation marker CD40, the level of nitric oxide, the generation of intracellular reactive oxygen species, as well as M1 macrophages cytokines including tumor necrosis factor-α, interleukin-1β, interleukin 12 p70, and interleukin 6. Further investigation showed that HMF induced M1 but not M2 phenotype polarization in RAW264.7 cells.

CONCLUSIONS

HMF can mainly exert anticancer activity via (1) cytotoxicity to human lung cancer cells by proliferation inhibition, cell cycle arrest, and apoptosis induction; and also via (2) immunomodulation via macrophage cells activation and M1 phenotype polarization induction.

Novel fucoidan based bioactive targeted nanoparticles from Undaria Pinnatifida for treatment of pancreatic cancer

Fucoidan is a marine polymer extracted from diverse types of brown algae. This polysaccharide showed great potential towards treatment of different types of cancer. In this study, the activity of fucoidan extracted from Undaria Pinnatifida was investigated against pancreatic cancer (one of the most life-threatening cancers). Then, in an attempt to enhance the polymer's activity against cancer cells, conversion the polymer solution to nanoparticles was suggested to enhance its delivery through pancreatic cancer surrounding stroma. Novel fucoidan based nanoparticles were elaborated by polyelectrolyte interaction with the positively charged, active targeting ligand lactoferrin. The formulation was optimized through the interplay between different factors. Effect of fucoidan solution along with its blank nanoparticles was tested on the viability of pancreatic cancer cells and its migration and invasion abilities. Results confirmed the cytotoxic ability of fucoidan against pancreatic cancer. IC50 value decreased by 2.3 folds when the polymer was converted to nanoparticles. The prepared nanosystems showed an enhanced ability to prevent pancreatic cancer cells' migration and invasion. Results suggested the potential of using these nanoparticles as bioactive dual-targeted system either blank or loaded with different anticancer agents for treatment for pancreatic cancer.

Molecular Mechanisms Underlying Cancer Preventive and Therapeutic Potential of Algal Polysaccharides

Background:

Algal polysaccharide and oligosaccharide derivatives have been shown to possess a variety of therapeutic potentials and drug delivery applications. Algal polysaccharides contain sulfated sugar monomers derived from seaweed including brown, red, and green microalgae. Here, in this review, the recent progress of algal polysaccharides’ therapeutic applications as anticancer agents, as well as underlying cellular and molecular mechanisms was investigated. Moreover, recent progress in the structural chemistry of important polysaccharides with anticancer activities were illustrated.

Methods:

Electronic databases including “Scopus”, “PubMed”, and “Cochrane library” were searched using the keywords “cancer”, or “tumor”, or “malignancy” in title/abstract, along with “algae”, or “algal” in the whole text until July 2018. Only English language papers were included.

Results:

The most common polysaccharides involved in cancer management were sulfated polysaccharides, Fucoidans, Carageenans, and Ulvan from different species of algae that have been recognized in vitro and in vivo. The underlying anticancer mechanisms of algal polysaccharides included induction of apoptosis, cell cycle arrest, modulation of transduction signaling pathways, suppression of migration and angiogenesis, as well as activation of immune responses and antioxidant system. VEGF/VEGFR2, TGFR/Smad/Snail, TLR4/ROS/ER, CXCL12/ CXCR4, TGFR/Smad7/Smurf2, PI3K/AKT/mTOR, PBK/TOPK, and β-catenin/Wnt are among the main cellular signaling pathways which have a key role in the preventive and therapeutic effects of algal polysaccharides against oncogenesis.

Conclusion:

Algal polysaccharides play a crucial role in the management of cancer and may be considered the next frontier in pharmaceutical research. Further well-designed clinical trials are mandatory to evaluate the efficacy and safety of algal polysaccharides in patients with cancer.

Anticancer effect of fucoidan on cell proliferation, cell cycle progression, genetic damage and apoptotic cell death in HepG2 cancer cells

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The centre of the attraction of this article is inevitably associated with fucoidan polymers in terms of brown seaweed such as Turbinaria conoides.

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Fucoidan in various cancer types exhibited by targeting apoptotic molecules and mitigate the toxicity of chemotherapeutic agents and radiation.

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To treat deadly liver cancer by identifying bioactive compounds available in the dietary supplement that rekindles the direction of research against cancer diseases.

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Fucoidan in a HepG2 cell line was studied with typical techniques such as cell viability, colony formation, cell migration, cell cycle progression, genetic damage and apoptosis along with their nuclear morphology and mitochondrial membrane potential.

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This study concluded that the fucoidan contain brown seaweeds consumed as dietary supplement not predispose to liver cancer.

The centre of the attraction of this article is inevitably associated with fucoidan polymers in terms of brown seaweed such as Turbinaria conoides. Fucoidan is a sulphated polysaccharide constitutes fucose as a major principle sugar along with other monosugars such as glucuronic acid, xylose and galactose. The core value of fucoidan in terms of various cancer types were substantially exhibited through targeting the key apoptotic molecules and subsequently mitigate the toxicity that are essentially included in the chemotherapeutic agents and radiation. The pragmatic investigation about the anti-cancer effect of fucoidan in a hepatoblastoma-derived (HepG2) cell line was thoroughly analyzed by the typical techniques such as cell viability, colony formation, cell migration, cell cycle progression, genetic damage and apoptosis along with their nuclear morphology and mitochondrial membrane potential. Following the analyzes, the cell viability was precisely evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. And hence, cell cycle arrest and apoptosis was appropriately examined staining with propidium iodide (PI) and annexin V-fluorescein isothiocyante (FITC) by flowcytometer, respectively. Primarily, genetic damage by fucoidan in HepG2 cell line was evaluated by following Trevigen’s comet assay kit. In addition, alteration of nuclear content and mitochondrial membrane potential were also detected with Hoechst and mitochondrial membrane potential dye (JC-1: 5,5′6,6′-tetrachloro-1,1′3,3′tetraethylbenzimi-dazolycarbocyanine iodide) by fluorescence microscopy, respectively. The results of the present study showed that cells constituted with fucoidan/quercetin standard at 50, 100 and 200 μg/ml exhibited cell viability about 71, 60 & 40/80, 65 & 45%, respectively. The above recorded effect of fucoidan was a concentration-dependant inhibition on the basis of decline in colony forming and cell migration potential of HepG2 cancer cells. Compared with untreated control, fucoidan consituted cells were significantly (p ≤  0.05) accumulated proliferative cells in the G₀/G₁ phase of the cell cycle in a concentration dependent manner. Increasing concentration of fucoidan (50,100 and 200 μg/ml) was remarkably enhanced the DNA damage which reflected through tail moment value of 3.8, 7.1 & 12.8 folds with respect to the untreated control. Fucoidan induced total apoptotic cells were observed ∼20–40% at 50–200 μg/ml concentrations. The apoptotic cell formation effected by change in the nuclear content and mitochondrial membrane potential was confirmed in HepG2 cancer cells under fluorescence microscopy. It was eventually concluded that the fucoidan display promising anti-cancer activity against HepG2 cancer cells by promoting the inhibition of cell proliferation, migration and cell arrest on concentration dependent-manner that was well correlated with genetic damage and apoptosis.

Polysaccharide from Spirulina platensis ameliorates diphenoxylate-induced constipation symptoms in mice

The aim of this study is to probe new functions of a polysaccharide from Spirulina platensis (PSP) on constipation and intestinal microbiota in mice. Diphenoxylate-induced constipation in mice was treated with different doses of PSP, followed by examining the defecation patterns, levels of acetyl cholinesterase (AchE), nitric oxide (NO), and tissue section histopathology. The composition of intestinal microbiota was determined by genome sequencing analysis of the 16S rDNA. This study found that the average molecular weight of PSP was 29, 600 Da, and mainly monosaccharides of PSP were rhamnose (24.7%), glucose (16.15%) and galactose (13.32%). The beneficial effects of PSP treatment include defecation improvement, increase of AchE activity, reduction of NO concentration, renovation of the damaged intestinal villus and affection on the expression of some related genes in the constipated mice. In addition, PSP had significant effects on the gut microbiota, showing the enhancement in abundance of beneficial bacteria including Akkermansia, Lactobacillus, Butyricimonas, Candidatus Arthromitus and Prevotella, and the reduction in abundance of harmful bacteria such as Clostridium and Dorea. The present s uncovered a new function of PSP, indicating that PSP could be used in constipation therapies.

Pathway Analysis of Fucoidan Activity Using a Yeast Gene Deletion Library Screen

Fucoidan, the sulfated fucose-rich polysaccharide derived from brown macroalgae, was reported to display some anti-cancer effects in in vitro and in vivo models that included apoptosis and cell cycle arrest. The proposed mechanisms of action involve enhanced immune surveillance and direct pro-apoptotic effects via the activation of cell signaling pathways that remain largely uncharacterized. This study aimed to identify cellular pathways influenced by fucoidan using an unbiased genetic approach to generate additional insights into the anti-cancer effects of fucoidan. Drug⁻gene interactions of Undaria pinnatifida fucoidan were assessed by a systematic screen of the entire set of 4,733 halpoid Saccharomyces cerevsiae gene deletion strains. Some of the findings were confirmed using cell cycle analysis and DNA damage detection in non-immortalized human dermal fibroblasts and colon cancer cells. The yeast deletion library screen and subsequent pathway and interactome analysis identified global effects of fucoidan on a wide range of eukaryotic cellular processes, including RNA metabolism, protein synthesis, sorting, targeting and transport, carbohydrate metabolism, mitochondrial maintenance, cell cycle regulation, and DNA damage repair-related pathways. Fucoidan also reduced clonogenic survival, induced DNA damage and G1-arrest in colon cancer cells, while these effects were not observed in non-immortalized human fibroblasts. Our results demonstrate global effects of fucoidan in diverse cellular processes in eukaryotic cells and further our understanding about the inhibitory effect of Undaria pinnatifida fucoidan on the growth of human cancer cells.

The effect of fucoidan on intestinal flora and intestinal barrier function in rats with breast cancer

Recent research studies have shown that the intestinal flora are related to the occurrence and progress of breast cancer. This study investigates the effect of fucoidan on intestinal flora and intestinal barrier function in rats with 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast cancers. Sixty female Sprague-Dawley rats were randomly assigned to the control group, the model group, and the F1 and F2 groups, which were fed fucoidan at concentrations of 200 and 400 mg per kg bw (body weight), respectively. Intestinal histopathological analysis was performed and 16S rDNA high-throughput sequencing was used to provide an overview of the intestinal flora composition. The contents of d-lactic acid (d-LA), diamine oxidase (DAO) and endotoxin in plasma were detected by ELISA. Expression levels of the tight junction (TJ) proteins, phosphorylated p38 MAPK and ERK1/2 were measured using western blotting. Our results suggested that the intestinal wall of the model group was damaged. However, after fucoidan intervention, the villi were gradually restored. ELISA showed that the levels of plasma endotoxin, d-LA and DAO decreased in the F1 and F2 groups compared to those in the model group. Fucoidan treatment also increased the expressions of ZO-1, occludin, claudin-1 and claudin-8. Furthermore, the expression levels of phosphorylated p38 MAPK and ERK1/2 were upregulated in fucoidan treatment groups. The results of 16S rDNA high-throughput sequencing indicated that fucoidan increased the diversity of the intestinal microbiota and induced changes in microbial composition, with the increased Bacteroidetes/Firmicutes phylum ratio. In conclusion, the supplement of fucoidan could improve the fecal microbiota composition and repair the intestinal barrier function. The study suggested the use of fucoidan as an intestinal flora modulator for potential prevention of breast cancer.

The Effect of Fucoidan from the Brown Alga Fucus evanescence on the Activity of α-N-Acetylgalactosaminidase of Human Colon Carcinoma Cells

α-N-acetylgalactosaminidase (EC 3.2.1.49) (alpha-NaGalase) catalyzes the hydrolysis of N-acetamido-2-deoxy-α-d-galactoside residues from non-reducing ends of various complex carbohydrates and glycoconjugates. It is known that human cancer cells express an alpha-NaGalase, which accumulates in the blood plasma of patients. The enzyme deglycosylates the Gc protein-derived macrophage activating factor (GcMAF) and inhibits macrophage activity acting as an immunosuppressor. The high specific activity 0.033 ± 0.002 μmol mg−1 min−1 of the enzyme was found in human colon carcinoma cells DLD-1. The alpha-NaGalase of DLD-1 cells was isolated and biochemical characterized. The enzyme exhibits maximum activity at pH 5.2 and temperature 55 °C. The Km is 2.15 mM, Vmax⁻0.021 μmol min−1 mL−1, kcat⁻1.55 min−1 and kcat/Km⁻0.72 min−1 mM−1 at 37 °C, pH 5.2. The effects of fucoidan from the brown alga Fucus evanescence on the activity of alpha-NaGalase in human colon carcinoma DLD-1 cells and on the biosynthesis of this enzyme were investigated. It was shown that fucoidan did not inhibit free alpha-NaGalase, however, it reduced the expression of the enzyme in the DLD-1 cells at IC50 73 ± 4 μg mL−1.