Fucoidan extract from brown seaweed ( Sargassum echinocarpum ): molecular weight, elemental composition, selectivity and anticancer activity against breast cancer cells

Molecular weight and elemental composition contribute to fucoidan bioactivity. Fucoidan extract from S. echinocarpum had three fractions varying in molecular weights (Mw), whereas crude fucoidan extract had a moderate Mw of 2,034.31 kDa. The fucoidan extract contained several elements, including C (38.19%), O (44.46%), and S (2.61%). Moreover, the fucoidan extract exhibited toxicity to breast cancer cells (MCF-7) at 297.58 ± 2.40 ppm. The extract induced apoptosis by 49.78%, 72.05%, and 89.35% after incubation for 24, 48, and 72 h, respectively. Fucoidan increased MDA levels in MCF-7 cells, indicating its anticancer properties through the induction of apoptosis-induced lipid peroxidation. Furthermore, the anticancer activity of fucoidan extract was not significantly different from the standard fucoidan (F. vesiculosus). In addition, the extract was selective and non-toxic to human normal cells (TIG 1-20), indicating its safety for consumption and potential as an anticancer agent derived from marine algae.