masterThesis
Papel protetor dos polissacarídeos sulfatados da alga verde Udotea Flabellum (J.Ellis & Solander) M.Howe em células expostas ao dano oxidativo
Fecha
2018-08-31Registro en:
PRESA, Fernando Bastos. Papel protetor dos polissacarídeos sulfatados da alga verde Udotea Flabellum (J.Ellis & Solander) M.Howe em células expostas ao dano oxidativo. 2018. 43f. Dissertação (Mestrado em Ciências da Saúde) - Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, 2018.
Autor
Presa, Fernando Bastos
Resumen
Sulfated polysaccharides (SPs) are compounds found primarily in animals and
seaweed. They present a diversity of biological and pharmacological activities,
including antitumor, antiviral, antioxidant. The major animal SPs are
glycosaminoglycans, some of these polysaccharides, due to their metal chelating
activity, can protect cells from oxidative damage when they are exposed to copper
or iron and ascorbate. Seaweed SPs, although they also present metal chelating
activity, have not yet been evaluated in this sense. In the state of Rio Grande do
Norte the green seaweed Udotea flabellum is found easily. In this work, the SPs of
this seaweed were extracted through proteolysis and fractionated with acetone,
which gave rise to six SP-rich fractions (UF-0.3, UF-0.6, UF-0.7, UF- 2.0). The SPs
of this seaweed are sulfated heterogalactans, which was confirmed by chemical and
electrophoretic analysis. All fractions nether affect the ability of 3T3 cells to reduce
3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium (MTT) bromide, nor did they
affect the proliferation of these cells. The fractions UF-0.3 and UF-1.0 showed
contamination with proteins and therefore were not evaluated in other tests. The
other fractions showed iron and copper chelating activity. When cells were exposed
to iron and ascorbate and fractions it was found that all fractions protected the cells
from oxidative damage. The fractions decreased the levels of lipid peroxidation and
the number of dead cells by apoptosis, as they prevented abrupt declines in the
levels of glutathione and superoxide dismutase within the cells exposed to oxidative
stress. The most effective fractions were UF0.7, when the cells were exposed to
iron and ascorbate, and in the case of copper and ascorbate, the most effective
fraction was UF-2.0. The data presented here indicate the potential of seaweed
SPS as protective agents for oxidative damage caused by metals (iron and copper).