Heterofucans from Dictyota menstrualis have anticoagulant activity

Abstract

Fucan is a term used to denote a family of sulfated L-fucose-rich polysaccharides which are present in the extracellular matrix of brown seaweed and in the egg jelly coat of sea urchins. Plant fucans have several biological activities, including anticoagulant and antithrombotic, related to the structural and chemical composition of polysaccharides. We have extracted sulfated polysaccharides from the brown seaweed Dictyota menstrualis by proteolytic digestion, followed by separation into 5 fractions by sequential acetone precipitation. Gel electrophoresis using 0.05 M 1,3-diaminopropane-acetate buffer, pH 9.0, stained with 0.1% toluidine blue, showed the presence of sulfated polysaccharides in all fractions. The chemical analyses demonstrated that all fractions are composed mainly of fucose, xylose, galactose, uronic acid, and sulfate. The anticoagulant activity of these heterofucans was determined by activated partial thromboplastin time (APTT) using citrate normal human plasma. Only the fucans F1.0v and F1.5v showed anticoagulant activity. To prolong the coagulation time to double the baseline value in the APTT, the required concentration of fucan F1.0v (20 µg/ml) was only 4.88-fold higher than that of the low molecular weight heparin Clexane ® (4.1 µg/ml), whereas 80 µg/ml fucan 1.5 was needed to obtain the same effect. For both fucans this effect was abolished by desulfation. These polymers are composed of fucose, xylose, uronic acid, galactose, and sulfate at molar ratios of 1.0:0.8:0.7:0.8:0.4 and 1.0:0.3:0.4:1.5:1.3, respectively. This is the fist report indicating the presence of a heterofucan with higher anticoagulant activity from brown seaweed.

Bioactive potential and possible health effects of edible brown seaweeds

“…Anti-coagulant activity of sulfated polysaccharides has been identified from several brown seaweeds such as Padina gymnospora (Silva et al, 2005), Dictyota menstrualis (Albuquerque et al, 2004) and F. vesiculosus (Mourão, 2004). Yoon, Pyun, Hwang, and Mourão (2007) isolated an acidic polysaccharide from Laminaria cichorioides collected from east coast of Korea which was shown to have a potent anti-coagulant activity mainly mediated by thrombin inhibition by heparin cofactor II.…”

Anticoagulant and antiplatelet properties of the latex of unripe fruits of Carica papaya L. (Caricaceae)

“…3 Drugs currently used as anticoagulants have various limitations, thus being far from ideal. 4 Warfarin has numerous interactions with diet and other medications, requires complex individualized dosing, and has a delayed onset of action. 5 Unfractionated heparins and low-molecular-weight heparins, which require parenteral administration, pose a risk of heparin-induced thrombocytopenia, osteoporosis, and hemorrhage.…”

Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora

“…Several homofucans with demonstrated anticoagulant activity have been extracted from different brown seaweeds (5,14). However, there are only few reports of their mechanism of action.…”