title: Heparinoids algal and their anticoagulant, hemorrhagic activities and platelet aggregation.
abstract: Polysaccharides extracted from brown marine algae represent a source of marine compounds with potential applications in medicine. Heparin-like compounds, fucoidans, have been proposed as alternatives to the anticoagulant heparin, which is prepared from mucous membrane of mammals. In this study, the activity of anticoagulant in activated partial thromboplastin time (APTT) and prothrombin time (PT) tests was assessed in the fucoidan (TF), from seaweed Fucus vesiculosus, partially desulfated fucoidans (PDF), desulfated fucoidans (DF) and purified fractions F1, F2 and F3 in acetone. Studies were also conducted to assess these polysaccharides for platelet aggregation and hemorrhagic activity. The APTT test showed high activity at 5 microg (> or = 240s) for TF, F1 and F2 (P<0.001). PT test showed high anticoagulant activity at 50 microg (> or = 120s) for F1 (P<0.001). Fraction F3, with low MW (15.2 kDa) and sulfate content (26.1%), had little effect in these two in vitro tests (P<0.001). These compounds demonstrated a two-phase response to platelet aggregation at 50 microg/mL. However, at a concentration of 0.1 mg/mL, a hypoaggregate profile was observed for all fractions tested (P<0.001). The analysis showed that fucoidans irreversibly induced platelet aggregation in high concentration. These polymers have low hemorrhagic effect when compared to heparin.
authors.affiliation: Departamento de Bioquímica, Centro de Biociências, Universidade Federal do Rio Grande do Norte, 3000 Campus Universitário, Bairro Lagoa Nova, CEP 59072-970 Natal, Rio Grande do Norte, Brazil.
authors.forename: Tarciana Carvalho G
authors.initials: TC
authors.lastname: de Azevedo
authors.forename: Maria Emília B
authors.initials: ME
authors.lastname: Bezerra
authors.forename: Maria da Glória de L
authors.initials: Mda G
authors.lastname: Santos
authors.forename: Leonardo Augusto
authors.initials: LA
authors.lastname: Souza
authors.forename: Cybelle T
authors.initials: CT
authors.lastname: Marques
authors.forename: Norma Maria B
authors.initials: NM
authors.lastname: Benevides
authors.forename: Edda Lisboa
authors.initials: EL
authors.lastname: Leite
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology*; D065427:Factor Xa Inhibitors; D044645:Fucus / Q000737:chemistry*; D006470:Hemorrhage / Q000139:chemically induced; D006496:Heparinoids / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D010314:Partial Thromboplastin Time; D010974:Platelet Aggregation / Q000187:drug effects*; D011134:Polysaccharides / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology*; D011517:Prothrombin Time; D051381:Rats; D017208:Rats, Wistar; D012624:Seaweed / Q000737:chemistry; D013917:Thrombin / Q000037:antagonists & inhibitors
chemical_list: D000925:Anticoagulants; D065427:Factor Xa Inhibitors; D006496:Heparinoids; D011134:Polysaccharides; C007789:fucoidan; D013917:Thrombin