Made available in DSpace on 2014-12-17T14:03:35Z (GMT). No. of bitstreams: 1
CelinaMPGD_TESE.pdf: 1816885 bytes, checksum: 1e39ca48cae61af571d696fef8f71be4 (MD5)
Previous issue date: 2012-10-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The present study examines the chemical composition and their effects on free
radicals, inflammation, angiogenesis, coagulation, VEGF effects and cellular
proliferation of a polysaccharides from alga Sargassum vulgare. The sulfated
polysaccharide was extracted from brown seaweed by proteolysis with enzymes
maxataze. The presence of proteins and sugars were observed in crude
polysaccharides. Fractionation of this crude extract was made with growing
concentration of acetone (0.3-1.5 v) and produced four groups of polysaccharides.
Anionic polysaccharides from brown seaweed Sargassum vulgare, SV1and PSV1
were fractionated (SV1) and purified (PSV1), and displayed with high total sugars
and sulfate content and very low level of protein. This fucan SV1 contains low levels
of protein and high carbohydrate and sulfate content. This polysaccharides prolonged
activated partial thromboplastin time (aPTT) at 50 μg (>240 s). SV1 was found to
have no effect on prothrombin time (PT), corresponding to the extrinsic pathway of
coagulation. SV1 exhibits high antithrombotic action in vivo, with a concentration ten
times higher than heparin. Polysaccharides from S. vulgare promoted direct inhibition
enzymatic activity of thrombin and stimulated enzymatic activity of FXa. SV1 showed
optimal inhibitory activity of thrombin (50.2?0.28%) at a concentration of 25 μg/mL.
Its antioxidant action on scavenging radicals by DPPH was (22%), indicating the
polymer has no cytotoxic action (hemolytic) on ABO and Rh blood types in different
erythrocyte groups and displays strong anti-inflammatory action on all concentrations
tested in the carrageenan-induced paw edema model, demonstrated by reduced
edema and cellular infiltration. Angiogenesis is a dynamic process of proliferation and
differentiation. It requires endothelial proliferation, migration, and tube formation. In
this context, endothelial cells are a preferred target for several studies and therapies.
The antiangiogenic efficacy of polysaccharides was examined in vivo in the chick
chorioallantoic membrane (CAM) model by using fertilized eggs. Decreases in the
density of the capillaries were assessed and scored. The results showed that SV1
and PSV1 have an inhibitory effect on angiogenesis. These results were also
confirmed by inhibition tubulogenesis in rabbit aorta endothelial cell (RAEC) in
matrigel. These compounds were assessed in Apoptosis assay (Annexin V - FITC /
PI) and cell viability by MTT assay of RAEC. These polysaccharides do not affect the
viability and do not have apoptotic or necrotic action. RAEC cell when incubated with
SV1 and PSV1showed inhibition of VEGF secretion, observed when compounds
were incubated at 25, 50 and 100 μg/μL. The VEGF secretion with the RAEC cell line
for 24 h, was more effective for PSV1 at 50 μg/μL(71.4%) than SV1 100 μg/μL
(75.9%). SV1 and PSV1 had an antiproliferative action (47%) against tumor cell line
HeLa. Our results indicate that these sulfated polysaccharides have antiangiogenic
and antitumoral actions / O presente estudo analisa a composi??o qu?mica e seus efeitos sobre os radicais
livres, inflama??o, angiog?nese, coagula??o, VEGF e prolifera??o celular dos
polissacar?deos de uma alga Sargassum vulgare. O polissac?rido sulfatado foi
extra?do a partir de algas marrons por prote?lise com a enzima maxataze. A
presen?a de prote?nas e a??cares foram observados no cru de polissacarideos.
Fracionamento do o extrato bruto foi feito com concentra??es crescente de acetona
(0,3-1,5 v), produzindo quatro grupos de polissacarideos. Estes compostos
ani?nicos da alga S. vulgare, foram fracionados (SV1) e purificados (PSV1)
exibindo com alta a??cares totais e sulfatecontent e n?vel muito baixo de prote?nas.A
fucana SV1 cont?m baixos n?veis de prote?na e de hidratos de carbono e alto teor de
sulfato. Este polissacar?deos prolongou o tempo de tromboplastina parcial activada
(aPTT) a 50 ug (>240 s). n?o foi observado qualquer efeito de SV1 sobre o tempo de
protrombina (PT), que corresponde a via extr?nseca da coagula??o. SV1 exibiu alta
a??o antitromb?tica in vivo, com uma concentra??o 10 vezes maior do que a
heparina. SV1 promoveu a actividade de inibi??o enzim?tica direta da trombina e
estimulou a atividade enzim?tica do FXa. Mostrou tamb?m, atividade inibidora
optima de trombina (50,2 ? 0,28%) a uma concentra??o de 25 ug / mL. A sua ac??o
anti-oxidante de radicais scavenging por DPPH foi de (22%), indicando que o
pol?mero n?o tem qualquer a??o citot?xica (hemol?tica) em tipos de sangue ABO e
Rh, em diferentes grupos de eritr?citos e exibindo alta a??o anti-inflamat?ria em
edema de pata de ratos Wistar em todas as concentra??es testadas induzida por
carragenina. Tal processo foi demonstrado por edema e infiltra??o celular. A
angiogenese ? um processo din?mico de prolifera??o e diferencia??o. Ele requer
prolifera??o endotelial, migra??o, e a forma??o do tubo. Neste contexto, as c?lulas
endoteliais s?o um alvo preferido para muitos estudos e terapias. A efic?cia antiangiogenico
de polissacar?deos foi examinada in vivo na membrana corioalant?ica
pinto (CAM) usando-se ovos fertilizados. Diminui??es na densidade dos capilares
foram avaliados e pontuados. Os resultados mostraram que SV1 e PSV1 tem um
efeito inibidor da angiogenese. Estes resultados foram tamb?m confirmados por
tubulogenesis inibi??o na c?lula endotelial da aorta de coelho (RAEC) em matrigel.
C?lulas RAEC quando foram incubadas com SV1and PSV1 demonstraram inibi??o
da secre??o de VEGF, a 25, 50 e 100 ug/mL. A secre??o de VEGF com a linha de
c?lulas RAEC durante 24 h, foi mais eficaz para PSV1 a 50 ug / mL (71,4%) do que
SV1 100 ug / mL (75,9%). SV1 e PSV1 posuiram uma ac??o antiproliferativa (47%)
contra as c?lulas tumorais tipo HeLa. Estes compostos foram avaliados tamb?m, no
ensaio de apoptose (anexina V - FITC / PI) e a viabilidade celular pelo ensaio de
MTT de RAEC. Estes polissacar?deos n?o afetaram a viabilidade e n?o tiveram a??o
apopt?tica ou necr?tica. Nossos resultados indicam que estes polissacar?deos
sulfatados t?m a??es antiangiog?nica e antitumoral e constituem um importante alvo
biol?gico e farmacol?gico
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12570 |
| Date | 15 October 2012 |
| Creators | Dore, Celina Maria Pinto Guerra |
| Contributors | CPF:06341462468, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783254U6&dataRevisao=null, Cruz, Ana Katarina Menezes da, CPF:87588986468, http://lattes.cnpq.br/9810605697247961, Farias, Eduardo Henrique Cunha de, CPF:01164378473, http://lattes.cnpq.br/0933304924768138, Filgueira, Luciana Guimar?es Alves, CPF:01843965496, http://lattes.cnpq.br/9951316929526841, Carvalho, Maria Goretti Freire de, CPF:05601592420, http://lattes.cnpq.br/8934375314306198, Leite, Edda Lisboa |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Bioqu?mica, UFRN, BR, Bioqu?mica; Biologia Molecular |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0025 seconds