Anticomplementary and anticoagulant activities of purified fucans from Fucus vesiculosus
Azevedo, T.C.G.; Cordeiro, S.L.; Dantas, J.C.M.; Bezerra, M.E.B.; Marques, C.T.; Souza, M.C.R.; Cardoso, M.L.; Souza, L.A.R; Rocha, H.A.O.; Leite, E.L.
Departamento de Bioquímica, Universidade Federal do Rio grande do Norte. * Corresponding author: e-mail: ddaleite@cb.ufrn.br, fax: (84) 211-9208, Dep de Bioquímica, Centro de Ciências, Campus Universitário, Lagoa Nova, s/n, CEP 59082-970, Natal-RN, Brasil
The fucoidans are complex and ramified homopolysaccharides composed by a-fucose. These sulfated compounds have shown a big range of pharmacological activities. We have focused our attention on the action of a fucoidan and its purified fractions at blood coagulation and complement system. The polysaccharide (Ft) extracted from Fucus vesiculosus was fractionated in three fractions F1, F2 and F3 using 1, 2 and 3 volumes of acetone respectively. The anticoagulant activities of the fucoidan and its fractions were evaluated by Active Partial Thrombin Time (APTT) and Prothrombine Time assay (PT) using citrated normal human plasma. The alternative pathway of the system complement was evaluated by assay hemolytic using red blood cells from rabbit. The results of APPT test showed that Ft, F1 and F2 (5 µg/mL) have high anticoagulants activities 240.0 s. The fraction F3 draw out the coagulation time at 73.7 s in the same concentration. The results obtained with PT test to Ft, F1, F2 and F3 (50 µg/mL) were 81.5 s, 120 s, 57.1 s and 32.5 s respectively. The results of complement system assay showed that F2 and F3 decreased the hemolytic activity of this system in 30% and 40% respectively in compare to the control. The Ft and F1 did not show any effect. The results obtained suggest that the fucoidans F2 and F3 inhibit the hemolytic profile of the alternative pathway of the system complement. Besides, they possess high anticoagulant activity.
Supported by CAPES and CNPq
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