| dc.description.abstract | The coast of Rio Grande do Norte has more than 100 species of seaweed, mostly
unexplored regarding their pharmacological potential. The sulfated polysaccharides
(PS) are by far the more seaweed compounds studied, these present a range of
biological properties, such as anticoagulant activity, anti-inflammatory, antitumor and
antioxidant properties. In this study, we extract sulfated polysaccharide rich-extracts
of eleven algae from the coast of Rio Grande do Norte (Dictyota cervicornis;
Dictiopterys delicatula; Dictyota menstruallis; Dictyota mertensis; Sargassum
filipendula; Spatoglossum schröederi; Gracilaria caudata; Caulerpa cupresoides;
Caulerpa prolifera; Caulerpa sertularioides e Codim isthmocladum), and these were
evaluated for the potential anticoagulant, antioxidant and antiproliferative. All
polysaccharide extracts showed activity for anticoagulant, antioxidant and/or
antiproliferative activity, especially D. delicatula and S. filipendula, which showed the
most prominent pharmacological potential, thereby being chosen to have their
sulfated polysaccharides extracted. By fractionating method were obtained six
fractions rich in sulfated polysaccharides to the algae D. delicatula (DD-0,5V, DD-0,
7V, DD-1,0v, DD-1,3v, DD-1,5v and DD-2,0) and five fractions to the alga S.
filipendula (SF-0,5V, SF-0,7V, SF-1,0v, SF-1,5v and SF-2,0v). For the anticoagulant
assay only the fractions of D. delicatula showed activity, with emphasis on DD-1, 5v
that presented the most prominent activity, with APTT ratio similar to clexane® at 0.1
mg/mL. When evaluated the antioxidant potential, all fractions showed potential in all
tests (total antioxidant capacity, hydroxyl and superoxide radicals scavenging, ferrous
chelation and reducing power), however, the ability to chelate iron ions appears as
the main mechanism antioxidant of sulfated polysaccharides from seaweed. In
antiproliferative assay, all heterofucanas showed dose-dependent activity for the
inhibition of cell proliferation of HeLa, however, with the exception of SF-0,7V, SF-
1,0v and SF-1,5v, all fractions showed antiproliferative activity against MC3T3, a
normal cell line. The heterofucana SF-1,5V had its antiproliferative mechanism of
action evaluated. This heterofucan induces apoptosis in HeLa cells by a pathway
caspase independent, promoting the release of apoptosis Inducing Factor (AIF) in
the cytosol, which in turn induces chromatin condensation and DNA fragmentation
into 50Kb fragments. These results are significant in that they provide a mechanistic
framework for further exploring the use of SF-1.5v as a novel chemotherapeutics
against human cervical cancer. | |
