Fucoidan Purified from Sargassum polycystum Induces Apoptosis through Mitochondria-Mediated Pathway in HL-60 and MCF-7 Cells

Fucoidans are biocompatible, heterogeneous, and fucose rich sulfated polysaccharides biosynthesized in brown algae, which are renowned for their broad-spectrum biofunctional properties. As a continuation of our preliminary screening studies, the present work was undertaken to extract polysaccharides from the edible brown algae Sargassum polycystum by a modified enzyme assisted extraction process using Celluclast, a food-grade cellulase, and to purify fucoidan by DEAE-cellulose anion exchange chromatography. The apoptotic and antiproliferative properties of the purified fucoidan (F5) were evaluated on HL-60 and MCF-7 cells. Structural features were characterized by FTIR and NMR analysis. F5 indicated profound antiproliferative effects on HL-60 leukemia and MCF-7 breast cancer cells with IC50 values of 84.63 +/- 0.08 mu g mL(-1) and 93.62 +/- 3.53 mu g mL(-1) respectively. Further, F5 treatment increased the apoptotic body formation, DNA damage, and accumulation of HL-60 and MCF-7 cells in the Sub-G(1) phase of the cell cycle. The effects were found to proceed via the mitochondria-mediated apoptosis pathway. The Celluclast assisted extraction is a cost-efficient method of yielding fucoidan. With further studies in place, purified fucoidan of S. polycystum could be applied as functional ingredients in food and pharmaceuticals.