ABSTRACT
Angiogenesis is a dynamic proliferation and differentiation process. It requires endothelial proliferation, migration and tube formation. In this context, endothelial cells are a preferred target for several studies and therapies. Anionic polysaccharides (SV1 and PSV1) from brown seaweed Sargassum vulgare were fractionated (SV1), purified (PSV1) and displayed with high total sugars, sulfate content and very low level of protein. 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 the inhibition of tubulogenesis in rabbit aorta endothelial cell (RAEC) in matrigel. These compounds were assessed in an apoptosis assay (Annexin V-FITC/PI) and cell viability by MTT assay of RAEC. These polysaccharides did not affect the viability and did not have apoptotic or necrotic action. RAEC cell when incubated with SV1and PSV1 showed 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 for SV1 at 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 antitumor actions.
Subject(s)
Angiogenesis Inhibitors/pharmacology , Antineoplastic Agents/pharmacology , Polysaccharides/chemistry , Seaweed/chemistry , Animals , Aorta/cytology , Apoptosis , Cell Cycle , Cell Line , Chick Embryo , Chorioallantoic Membrane/drug effects , Collagen/chemistry , Drug Combinations , Endothelial Cells/cytology , Flow Cytometry , HeLa Cells , Humans , Laminin/chemistry , Melanoma, Experimental , Mice , Neovascularization, Pathologic/drug therapy , Plant Extracts/pharmacology , Proteoglycans/chemistry , Rabbits , Tetrazolium Salts , ThiazolesABSTRACT
The in vitro antioxidant activities of the following six sulfated polysaccharides were investigated: iota, kappa and lambda carrageenans, which are widely used in the food industry, fucoidan (homofucan) from the edible seaweed Fucus vesiculosus and fucans (heterofucans) F0.5 and F1.1 from the seaweed Padina gymnospora. With respect to the inhibition of superoxide radical formation, fucoidan had an IC(50) (the half maximal inhibitory concentration) of 0.058 mg.mL(-1), while the IC(50) for the kappa, iota and lambda carrageenans were 0.112, 0.332 and 0.046 mg.mL(-1), respectively. All of the samples had an inhibitory effect on the formation of hydroxyl radicals. The results of peroxidation tests showed that fucoidan had an IC(50) of 1.250 mg.mL(-1) and that the kappa, iota and lambda carrageenans had an IC(50) of 2.753 and 2.338 and 0.323 mg.mL(-1), respectively. Fucan fractions showed low antioxidant activity relative to fucoidan. These results clearly indicate the beneficial effect of algal polysaccharides as antioxidants.
