• ALGAE
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• v.20 no.4
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• pp.315-324
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• 2005

Anatomical organization of Stoechospermum marginatum reveals small cortical cells with moderately dense cytoplasm, overlying a multilayered medulla comparatively poor in cytoplasmic contents. The anticlinal walls of cortical cells show local thickenings rich in alginic acids. Sori form on both thallus surfaces and show tetrasporangia, paraphyses and sterile-cells. The unicellular paraphyses are rich in sulphated polysaccharides whereas multicellular ones have abundance of not only polysaccharides, but also of vacuoles and phenols. The sterile-cells are modified cortical cells present on either side of the tetrasporangium and bear cytoplasmic strands towards soral cavity. Various stages of tetrasporogenesis are seen in a single sorus. The developing tetrasporangium shows a two layered wall, where the outer one is rich in alginic acid and inner has sulphated polysaccharides. An apical pad aids tetraspore release. Also involved in the release process are sterile-cells, paraphyses and polysaccharides.

• Nutrition Research and Practice
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• v.8 no.4
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• pp.377-385
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• 2014

BACKGROUND/OBJECTIVES: Abundant consumption of seaweeds in the diet is epidemiologically linked to the reduction in risk of developing cancer. In larger cases, however, identification of particular seaweeds that are accountable for these effects is still lacking, hindering the recognition of competent dietary-based chemo preventive approaches. The aim of this research was to establish the antiproliferative potency and angiosuppressive mode of action of Stoechospermum marginatum seaweed methanolic extract using various experimental models. MATERIALS/METHODS: Among the 15 seaweeds screened for antiproliferative activity against Ehrlich ascites tumor (EAT) cell line, Stoechospermum marginatum extract (SME) was found to be the most promising. Therefore, it was further investigated for its anti-proliferative activity in-vitro against choriocarcinoma (BeWo) and non-transformed Human embryonic kidney (HEK 293) cells, and for its anti-migratory/tube formation activity against HUVEC cells in-vitro. Subsequently, the angiosuppressive activity of S. marginatum was established by inhibition of angiogenesis in in-vivo (peritoneal angiogenesis and chorioallantoic membrane assay) and ex-vivo (rat cornea assay) models. RESULTS: Most brown seaweed extracts inhibited the proliferation of EAT cells, while green and red seaweed extracts were much less effective. According to the results, SME selectively inhibited proliferation of BeWo cells in-vitro in a dose-dependent manner, but had a lesser effect on HEK 293 cells. SME also suppressed the migration and tube formation of HUVEC cells in-vitro. In addition, SME was able to suppress VEGF-induced angiogenesis in the chorio allantoic membrane, rat cornea, and tumor induced angiogenesis in the peritoneum of EAT bearing mice. A decrease in the microvessel density count and CD31 antigen staining of treated mice peritoneum provided further evidence of its angiosuppressive activity. CONCLUSIONS: Altogether, the data underline that VEGF mediated angiogenesis is the target for the angiosuppressive action of SME and could potentially be useful in cancer prevention or treatment involving stimulated angiogenesis.