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.