Isolation, Structural characterization, and antiproliferative activity of phycocolloids from the red seaweed Laurencia papillosa on MCF-7 human breast cancer cells.

Hydrocolloids from seaweeds (phycocolloids) have interesting functional properties like antiproliferative activity. Marine algae consumptions are linked to law cancer incidences in countries that traditionally consume marine products. In this study, we have investigated water-soluble sulfated polysaccharides isolated from the red seaweed Laurencia papillosa and determined their chemical characteristics and biological activities on the human breast cancer cell line MCF-7. Total polysaccharides were extracted and fractionated from L. papillosa and characterized using FTIR-ATR and NMR spectrometry. In addition, their approximate molar mass was determined by GPC method. The chemical characterization of purified polysaccharides reveals the presence of sulfated polysaccharides differentially dispersed in the algal cell wall. They are the three types of carrageenan, kappa, iota and lambda carrageenans, named LP-W1, -W2 and -W3 respectively. Biological effects and cytotoxicity of the identified of the three sulfated polysaccharide fractions were evaluated in MCF-7 cell line. Our results showed a significant inhibition of MCF-7 cell viability by dose-dependent manner for cells exposed to LP-W2 and LP-W3 polysaccharides for 24h. The mechanistic of LP fractions-mediated apoptosis in MCF-7 cells was demonstrated. The biological effects of L. papillosa SPs indicate that it may be a promising candidate for breast cancer prevention and therapy.

Anti-Proliferative Activity of λ-Carrageenan Through the Induction of Apoptosis in Human Breast Cancer Cells.

BACKGROUND: Sulfated Polysaccharides (SPs) possess spectrum of pharmacological and therapeutic properties that could attributed to their origins variation, chemical structures and biological activities. Various studies have shown the impact of SPs on proliferation in different cancer cell lines. OBJECTIVES: In this study, we have evaluated the biological effects of λ-carrageenan, a highly SP, extracted from the red seaweed Laurencia papillosa, on MDA-MB-231 cancer cell line. MATERIALS AND METHODS: MDA-MB-231 cells have treated with λ-carrageenan, the viability and apoptosis have assessed by the appropriate florescent probes on flow cytometer. The expression levels of mRNA of apoptotic genes have detected by real-time PCR analysis. RESULTS: Our results have indicated that the signaling pathway of λ-carrageenan inhibited the proliferation of MDA-MB-231 cells by up-regulating the pro-apoptotic genes caspase-8, caspase-9, caspase-3 which have been resulting the increased levels of active caspase-3 protein. Furthermore, This SP had that capacity to disrupt the mitochondrial function by altering the bax/bcl-2 ratio of expression which has considered an important element in apoptosis induction. CONCLUSIONS: The presented results have signposted that λ-carrageenan was a promising bioactive polymer which could be a potential candidate in preventing or treating breast cancer.