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

**Ilekuttige Priyan Shanura Fernando 1,2, Kalu Kapuge Asanka Sanjeewa 2, Hyo Geun Lee 2, Hyun-Soo Kim 3, Andaravaas Patabadige Jude Prasanna Vaas 4,5, Hondamuni Ireshika Chathurani De Silva 4, Chandrika Malkanthi Nanayakkara 6, Dampegamage Thusitha Udayangani Abeytunga 4, Dae-Sung Lee 7, Jung-Suck Lee 8,\* and You-Jin Jeon 2,9,\***


Received: 21 March 2020; Accepted: 6 April 2020; Published: 8 April 2020

**Abstract:** 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 μg mL−<sup>1</sup> and 93.62 ± 3.53 μg mL−<sup>1</sup> respectively. Further, F5 treatment increased the apoptotic body formation, DNA damage, and accumulation of HL-60 and MCF-7 cells in the Sub-G1 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.

**Keywords:** Sri Lankan algae; anticancer; sulfated polysaccharide; fucoidan; Celluclast; sargassum
