Fucoidan

Shibata, H., Nagaoka, M., Takeuchi, Y., Hashimoto, S., Ueyama, S., and Yokokura, T. (1998). Anti-ulcer effect of fucoidan from brown seaweed, Cladosiphon okamuranus Tokida. ]pn. Pharmacol. Ther. 26,1211-1215. 

Specihc poly anions such as dextran sulfate (DS) appear to exhibit strong anti-HIV activity in vitro [36,37]. Human oral administration of DS is poorly absorbed, but intravaneous administration does result in increased plasma lipolytic activity [38]. Poly anions that have been considered for intravaginal anti-HIV activity include DS, carrageenan, heparin, heparan sulfate, dermatan sulfate, pentosan polysulfate, fucoidan chondroitin sulfate, keratan sulfate, and PAVAS [21,22,39,40],... 

Cumashi, A., Ushakova, N. A., Preobrazhenskaya, M. E., D Incecco, A., Piccoli, A., Totani, L., Tinari, N., Morozevich, G. E., Berman, A. E., Bilan, M. I., Usov, A. I., Ustyuzhanina, N. E., et al. (2007). A comparative study of the anti-inflammatory, anticoagulant, antiangio-genic, and antiadhesive activities of nine different fucoidans from brown seaweeds. Glycobiology 17, 541-552. 

FIGURE 1 Potential hydrolysis rates of six structurally distinct polysaccharides in seawater (A) and surface sediments (B) from Skagerrak and Svalbard. Pull = pullulan, lam = laminarin, xyl = xylan, fu = fucoidan, ara = arabinogalactan, chon = chondroitin sulfate. Note the differences in scale on the y axes for sediments and for seawater. [Skagerrak data from Arnosti (2000).]... 

When Bilan et al. [26] fractionated the crude fucoidan of Fucus evanescens by ion-exchange chromatography on DEAE-Sephacel, using aqueous sodium chloride of increasing sodium chloride concentration as eluent, a fraction which was essentially a homofucan sulfate was isolated. This homofucan was shown to contain a linear backbone of alternating 3- and 4-linked-a-L-fucopyranose 2-sulfate residues. Also, some additional sulfation was observed on C-4 of the 3-linked residues, whereas a part of the remaining hydroxyl groups was randomly acetylated. 

HIV infection in humans is now pandemic. As of January 2006, the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) estimate that AIDS has killed more than 25 million people since it was first recognized on December 1, 1981, making it one of the most destructive pandemics in recorded history. Antiretroviral treatment reduces both the mortality and the morbidity of HIV infection, but routine access to antiretroviral medication is not available in all countries. An alternative therapy to circumvent this problem is the use of polyanionic substances, which demonstrated a number of promising features as potential anti-HIV drug candidates. In this respect, various SPs (e.g., heparin, DS, dextrin sulfate, cyclo dextrin sulfate, curdlan sulfate, pentosan polysulfate, mannan sulfate, sulfoevernan, and fucoidan) and derivatives thereof (e.g., O-acylated heparin, polyacetal polysulfate, polyvinyl alcohol sulfate, and modified cyclo dextrin sulfates) have been found to inhibit HIV replication in vitro at concentrations that are up to 10 000-fold lower than the cytotoxic concentration [2,71]. 

The anionic groups Most of the seaweed polysaccharides with antiviral activity carry only sulfate as their anionic group. Nevertheless, in the case of fucoidans both sulfate groups and uronic acids are present. Sulfated seaweed polysaccharides with degrees of sulfation lower than 20-22% usually do not show activity, unless other structural factors compensate the sulfate deficiency. 

The influence of the hydrophobic sites In fucoidans the interaction of the methyl groups with the hydrophobic pocket of HSV-1 gC seems, in addition to the electrostatic forces, to be decisive in the binding of the polysaccharide to the viral protein. 

Constituent of oligosaccharide of human milk, glycosides of some plants, some seaweeds (fucoidan) and some glycoproteins... 

Fucan is a sulfated polysaccharide, naturally present in algae such as Fucus vesiculosus or Ascophyllum nodosum. Fucan is a general name for a mixture of three polysaccharides, and among them, fucoidan (or homofucan) can be theoretically considered as an homopolymer of a-1,2 L-fucose-4-sulfate and has been studied as a ligand in the same way as fucan himself. Their interaction with two proteins implicated in the coagulation process (thrombin and antithrombin) has been studied and is at least partially ionic. However, the dissociation of the complex fucan-antithrombin seems to include a slower step which could be attributed to a conformation change of the fucan [18]. 

Other anti-HSV sulphated PS included sulphated galactans from the marine alga Bostrychia montagnei [89], the red seaweed Pterocladia capillacea [90], extracts of Cryptopleura ramosa and Nothogenia fastigiata, two red seaweeds from the South American coast [91,92], and fucoidans from the brown seaweed utricularis [93]. 

Among single fiber sources, cellulose decreased iron absorption when fed in sufficient amounts to rats (23.33) but not to monkeys (22) or chickens (3D Agar, carrageenan, alginate and fucoidan decreased iron balance (2 ) or iron uptake (29) in rats. The difference between the response of iron-depleted and iron-replete rats to alginate is of interest. Iron absorption was decreased in the latter but not in the former (29). 

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