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Fucoidans are a class of sulfated fucose-containing bioactive polysaccharides produced by brown algae. The biological effects exhibited by fucoidans are thought to be related to their sulfation. However, the lack of methods for sulfation control does not allow for a reliable conclusion about the influence of the position of certain sulfate groups on the observed biological effects. We identified the gene encoding the endo-acting fucoidan sulfatase swf5 in the marine bacterium Wenyingzhuangia fucanilytica CZ1127T. This is the first report on the sequence of fucoidan endo-sulfatase. Sulfatase SWF5 belongs to the subfamily S1_22 of the family S1. SWF5 was shown to remove 4O-sulfation in fucoidans composed from the alternating α-(1→3)- and α-(1→4)-linked residues of sulfated L-fucose but not from fucoidans with the α-(1→3)-linked backbone. The endo-sulfatase was used to selectively prepare 4O-desulfated fucoidan derivatives. It was shown that the 4O-desulfated fucoidans inhibit colony formation of DLD-1 and MCF-7 cells less effectively than unmodified fucoidans. Presumably, 4O-sulfation makes a significant contribution to the anticancer activity of fucoidans.

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It seems that safety of the impact of the UVA on the skin is associated with insidious identifying of early manifestation of damage and distant consequences of impact on the skin and the whole organism. The imagination of safety of UVA exposure has led to wide spread of radiator of UV rays of range A. This scientific research was devoted to identifying of positive and negative impact of UVA on the skin. The aim of the study was to investigate the morphological and functional state of the guinea pigs' skin under the influence of local fractional UVA radiation. Materials and methods. Studies were conducted on albino guinea pigs that weight 300-350 g. The local fractional regime of exposure was obtained by UV radiator OUFK-03, which generates mainly UVA radiation with the aim of creating the model of exposure in the most similar to real conditions. The shaved area (2x2 cm) of animals' skin (n=6) was exposed for 30 minutes for 5 days. Guinea pigs were located in a distance of 10 centimeters from the source of exposure. Experiments with animals were finished on the 6-th day after exposure. All animals were deduced from the experiment with the help of general anesthesia keeping the principles of bioethics with the aim of investigation of peculiarities of morphological changes of skin. Visible changes in the morphological and functional state of the skin were detected on the 6-th day after irradiation: signs of acute inflammation and a tendency to chronicity of the process, multiple, compared with normal, thickening of the epidermis, degenerative changes in epidermocytes, hyper- and parakeratosis, focal destructive changes in connective tissue fibers in the dermis, which are accompanied by reactive inflammatory processes. Signs of starting reparative processes in proliferative form of functional active fibroblasts and increasing of collagenogenesis at sites of damage of collagen and elastin fibers are market simultaneously. It is considered that the negative effects of UVA in studied regime on the skin, the task of developing of depending actions is to reduce negative UVA impact which will be the aim of our next researches.

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Genomic analysis of the marine bacterium Wenyingzhuangia fucanilytica CZ1127T revealed the presence of four fucoidanase genes fwf1, fwf2, fwf3, fwf4 that belonged to the glycoside hydrolase family 107 (GH107, CAZy), which is located in one gene cluster putatively involved in fucoidan catabolism. Genes encoding two fucoidanases fwf1 and fwf2 were cloned, and the proteins FWf1 and FWf2 were produced in Escherichia coli cells. The recombinant fucoidanases were purified and the biochemical properties of these enzymes were studied. The amino acid sequences of FWf1 and FWf2 showed 41 and 51% identity respectively with a fucoidanase FcnA from the marine bacterium Mariniflexile fucanivorans, with the established 3D structure. Structures of the oligosaccharides produced during enzymatic hydrolysis of fucoidan by FWf1 and FWf2 have been determined by NMR spectroscopy. Detailed substrate specificities of FWf1 and FWf2 were studied using fucoidans and sulfated fucooligosaccharides with different structures. Both fucoidanases catalyzed hydrolysis of 1→4-glycosidic bonds between sulfated α-l-fucose residues but had different specificities regarding sulfation patterns of the fucose residues in fucoidan molecules. Specific cleavage sites recognizable by the fucoidanases in fucoidan molecules were determined. The obtained results provide new knowledge about differences between specificities of the fucoidanases belonging to the GH107 family.

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The aim is to study the features of the influence of local ultraviolet radiation on the organization and structure of collagen fibers in the radiation area. The studies were performed on 30 albino guinea pigs weighing 400-500 g, exposed to local ultraviolet radiation. Animals were removed from the experiment after 2 hours, 4 hours, 3 days, 8 days after irradiation. The control group was intact guinea pigs. To assess the structure and location of collagen fibers, skin sections in the irradiated area were studied using histological methods with polarized light analysis of collagen, and they were also analyzed using a scoring system for three parameters: composition, refraction intensity, and orientation of collagen fibers. The revealed structural features of collagen fibers reflect the course of the process of degeneration of the collagen skeleton of the dermis with a violation of the orientation and ordering of collagen fibers and an increase in the content of type III collagen with an increase in the observation period. According to the results of a semi-quantitative assessment of the state of collagen fibers, a significant deterioration in their structure and composition was recorded starting from 4 hours after exposure to ultraviolet radiation and progressed with an increase in the observation period. On the 8th day, the maximum deviation from the structure of the normal dermis is determined by the total number of points. The influence of local ultraviolet radiation in the minimum erythema dose on the skin of guinea pigs leads to the development of disturbances of the organization (abnormal position and ordering) and structure (increase in collagen content of type III) of collagen fibers of the dermis, which progress with an increase of the observation period.

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Fucoidans are a group of homo-and hetero-polysaccharides, which necessarily contains residues of sulfated α-L-fucose. Fucoidans are found only in brown algae. These polysaccharides exhibit a wide spectrum of biological activity and have a great therapeutic potential. Enzymes capable of catalyzing the degradation of fucoidans are absent in the mammalian enzyme system. The question arises: is the transformation of fucoidan in mammals, particularly in human possible? Studies in vivo (in situ) and in vitro have demonstrated that high molecular weight fucoidans are absorbed across rat intestinal epithelial cells, accumulated by liver macrophages, and characterized by low levels in blood and urine. Using the example of the Okinawa Prefecture (Japan) residents, it was shown that Cladosiphon okamuranus alga is digested and the fucoidan contained in this alga is absorbed in the human body.

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The purpose of this study was to assess the impact of ultraviolet irradiation (UV) on morphological and functional condition of the skin in guinea pigs. The study involved 30 albino guinea pigs weighing 400-500 g subjected to local exposure to UV irradiation. Control group consisted of intact guinea pigs. Histological studies of the skin were carried out at different stages of the trial (2 hours, 4 hours, 3 days, 8 days following the exposure). Microscopic examination showed morphological signs of acute inflammation in the skin of animals within the first three days following the exposure to UV irradiation. Within 2 hours following the exposure to UV irradiation these changes were minimal with signs of mild exudative changes. In 4 hours after the exposure histological changes increased. The specimens were also found to contain altered apoptotic keratinocytes (sunburn cells). Histopathological changes persisted and reached maximum severity by the 3rd day. Within post-erythema period (the 8th day) proliferative, hyperplastic, degenerative and dystrophic changes in the skin persisted. The prolonged nature of the changes in the skin is suggestive of the development of chronic inflammation in the skin of guinea pigs subjected to local exposure to UV irradiation.

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The review summarizes results of studies of effects of sulfated polysaccharides from seaweed on herpesviruses and the course of herpesvirus infections. Importance of this problem is determined by the prevalence of herpesviruses that can persist in the human body and demonstrate a high degree of immune mimicry and resistance to antiviral agents. A wide range of physiological action of sulfated polysaccharides, receptor agonists of innate and adaptive immune cells, which possess potent antiviral, antioxidant and anti-inflammatory activities, open the possibility of their use for creation of new generation pharmacological substances and agents with associated activity for the treatment of herpesvirus infections.

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In the review there are considered the recent data on the perspectives of the use of polysaccharides (PS) from marine hydrobionts for nhibition of formation of bacterial biofilms, which play a significant role in the onset and process of different infections, as well as for design of antiadhesive coatings on medical produce. Particular attention is paid to antiadhesive properties of natural PS from marine microorganisms, algae and invertebrate animals, which prevent formation of biofilms. Antibiofilm PS possess such positive characteristics, as biocompatibility and biodegradability, that is of great interest for medical and industrial applications. The possibility of simultaneous use of complexes of compounds of different chemical nature and mechanisms of action in infectious diseases, involving biofilm formation is of special interest. It is believed that biologically active substances from marine hydrobionts could serve as the basis for development of new antibiofilm drugs, including complex ones.

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At present the increase of antibiotic resistance in infection agents to antimicrobial drugs requires discovery of new antimicrobial substances with improved pharmacological properties and novel mechanisms of action, to which microorganisms do not develop resistance. Three areas are of interest for the search: recovery of new compounds from natural objects, including aquatic organisms, chemical modification of the known antibiotic molecules, discovery of compounds with antimicrobial activity among some new chemical structures which have no analogues in nature. The review is mainly concerned with discussion of antibacterial, antiviral and antifungal activity of sulfated polysaccharides (fucoidans) and extracts of brown, red and green algae, as well as of antioxidant, antiinflammatory, immunomodulatory and antiendotoxin properties that contribute to their antiinfective action. Such an activity makes fucoidans promising as a basis for developing new drugs for therapy of infectious diseases.

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The effect of sulfated polysaccharide fucoidan from the brown alga Laminaria japonica on morphological characteristics of mouse lymphoid organs, subpopulations of spleen mononuclear leukocytes, cytokine production and cytotoxic activity of splenocytes has been investigated. Fucoidan promoted activation and proliferation of lymphoid hematopoietic cells in primary and secondary immunogenesis bodies, increased expression of markers CD19, NK, NKT, CD25, MHC II, TCR, TLR2 and TLR4, the cytotoxic activity of splenocytes and production of immunoregulatory and proinflammatory cytokines (IL- 2, IL-12, IFN-g, TNF-a, IL-6). This suggests activation of effector mechanisms of innate immunity and adaptive immune responses via the Th-1 type.

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The effects of six 1,3;1,6-ß-D-glucooligo- and polysaccharides with different structures (ranging from 1 to 10 kDa in molecular mass and containing 10-25% of ß-1,6-linked glucose residues) from brown algae, Saccharina cichorioides, on development of the chum salmon, Oncorhynchus keta (Walbaum), were evaluated. Exposure of chum salmon eggs to 1,3;1,6-ß-D-glucans with a molecular mass of more than 2 kDa increased the survival of embryos and juveniles and their resistance to Saprolegnia infection by up to 2.5-fold, leading to a weight gain in juveniles of 40-55% compared with The control chum salmons. The 1,3;1,6-ß-D-glucans with molecular mass of 6-8 kDa and used at a at concentration of 0.5 mg mL(-1) rendered the best stimulative effect.

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This review discusses the catalytic properties, activity regulation, structure, and functions of O-glycoside hydrolases from marine organisms exemplified by endo-1→3-ß-D-glucanases of marine invertebrates.

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A specific 1→3-ß-D-glucanase with molecular mass 37 kDa was isolated in homogeneous state from crystalline style of the commercial marine mollusk Tapes literata. It exhibits maximal activity within the pH range from 4.5 to 7.5 at 45°C. The 1→3-ß-D-glucanase catalyzes hydrolysis of ß-1→3 bonds in glucans as an endoenzyme with retention of bond configuration, and it has transglycosylating activity. The K(m) for hydrolysis of laminaran is 0.25 mg/ml. The enzyme is classified as a glucan endo-(1→3)-ß-D-glucosidase (EC 3.2.1.39). The cDNA encoding this 1→3-ß-D-glucanase from T. literata was sequenced, and the amino acid sequence of the enzyme was determined. The endo-1→3-ß-D-glucanase from T. literata was assigned to the 16th structural family (GHF 16) of O-glycoside hydrolases.

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We studied the interactions between sulfated polysaccharides, fucoidans from sea brown algae Laminaria japonica, Laminaria cichorioides, and Fucus evanescens, with human Toll-like receptors (TLR) expressed on membranes of cultured human embryonic kidney cells (HEK293-null, HEK293-TLR2/CD14, HEK293-hTLR4/CD14-MD2, and HEK293-hTLR5). Fucoidans interacted with TLR-2 and TLR-4, but not with TLR-5, and were nontoxic for the cell cultures. L. japonica fucoidan (1 mg/ml), L. cichorioides fucoidan (100 µg/ml and 1 mg/ml), and F. evanescens fucoidan (10 µg/ml-1 mg/ml) activated transcription nuclear factor NF-Ï°B by binding specifically to TLR-2. L. japonica fucoidan (100 µg/ml and 1 mg/ml), L. cichorioides fucoidan (10 µg/ml-1 mg/ml), and F. evanescens fucoidan (1 µg/ml-1 mg/ml) activated NF-Ï°B via binding to TLR-4. These results indicated that fucoidans could induce in vivo defense from pathogenic microorganisms of various classes.

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The activities of hydrolases (acid phosphatase, RNase, and proteases) in healthy and tobacco mosaic virus-infected leaves of Nicotiana tabacum L. var. Samsun, both untreated and treated with polysaccharides (PS) (1,3;1,6-ß-D-glucan, fucoidan, and κ/ß-carrageenan), were determined. The PS lead to substantial increase in the hydrolase level. The percentage of viral particles undergoing destructive change also increases in leaves treated with PS 24 h before infection. We suppose that the PS-mediated hydrolase activation promotes intracellular destruction of the viral particles and, thus, comprises one of the PS-induced protective mechanisms limiting intracellular viral accumulation.

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Specimens of fucoidan extracted from Fucus evanescens were purified from protein and polyphenols, deacetylated and depolymerized by fucoidanase for evaluation of their biological activity. Deacetylation did not modify the capacity of fucoidan to inhibit thrombin and factor Xa, while purification from protein and polyphenols reduced this capacity. Depolymerization of fucoidan increased its capacity to inhibit thrombin mainly through heparin cofactor II. All the studied specimens formed complexes with protamine sulfate.

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UNLABELLED: The search for the substances sensitizing cancer cells to apoptosis induction by chemotherapeutic agents is a task of high importance in the modern strategy of anticancer therapy. THE AIM of the study was to investigate the apoptogenic and apoptosis-modulating activities of fucoidan (sulfated polysaccharide) isolated from far-eastern brown seaweeds Fucus evanescens in two human malignant lymphoid cell lines, MT-4 and Namalwa. METHODS: Apoptosis was assessed morphologically and quantified by flow cytometry analysis of cells stained with propidium iodide. Caspase-3 activation was assayed by flow cytometry with the aid of labeled monoclonal antibodies. RESULTS: The fucoidan at 500 microg/ml was not cytotoxic in MT-4 or Namalwa cells even in the setting of long-term presence in culture medium up to 14 days. Nevertheless, pretreatment of MT-4 but not Namalwa cells with fucoidan followed by the exposure to DNA topoisomerase II inhibitor etoposide led to about two-fold increase in the relative apoptotic index as compared with etoposide alone. Apoptosis enhancement of MT-4 cells by fucoidan was not accompanied by further increase in the number of the cells with active form of caspase-3. CONCLUSION: The present findings demonstrate for the first time that fucoidan enhances etoposide induced caspase-dependent cell death pathway in MT-4 but not Namalwa cell line. The mechanisms of such enhancement do not seem to be related directly to caspase-3 activation.

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The fragmentation of the biologically active 1,3;1,6-beta-D-glucan Antivir by endo-1,3-beta-D-glucanase LIV from crystalline styles of the marine mollusk Spisula sachalinensis was carried out. It was found that low molecular mass oligomers possessing a stabilizing effect on membranes and anti-viral activity against tobacco mosaic virus appeared in the process of enzymatic hydrolysis of Antivir. Biological activity of 1,3;1,6-beta-D-glucooligo- and polysaccharides was found to be associated with molecular mass (polymerization degree (n) not less than 14) and with presence of intralinked beta-1,6-connected monosaccharide residues. Probably, decrease in molecular mass is compensated by increase in number of intralinked beta-1,6-connected monosaccharide residues.

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Antitumor and antimetastatic activities of fucoidan, a sulfated polysaccharide isolated from Fucus evanescens (brown alga in Okhotsk sea), was studied in C57Bl/6 mice with transplanted Lewis lung adenocarcinoma. Fucoidan after single and repeated administration in a dose of 10 mg/kg produced moderate antitumor and antimetastatic effects and potentiated the antimetastatic, but not antitumor activities of cyclophosphamide. Fucoidan in a dose of 25 mg/kg potentiated the toxic effect of cyclophosphamide.

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Fucoidans isolated from Fucus evanescens and Laminaria cichorioides kelp can inhibit thrombin and factor Xa of the blood coagulation system. In rats, intravenous injection of fucoidans dose-dependently increased anticoagulant activity of the plasma. Fucoidans can form complexes with protamine sulfate. The observed quantitative differences in the action of fucoidans can result from different sulfation degree and the presence of various types of glycoside bonds in polysaccharide molecules.

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