Effect of enzyme-assisted extract of Sargassum coreanum on induction of apoptosis in HL-60 tumor cells

In order to effectively prepare useful components from Sargassum coreanum, enzyme-assisted extraction was adapted to extraction processing of the seaweed. Our previous studies have shown that Neutrase extract of S. coreanum exhibited the strongest antioxidant activities among ten enzymatic extracts. It is reported that many antioxidant substances have anticancer or anticarcinogenic properties. Thus, Neutrase extract, which possessed a strong antioxidant activity in the previous study, was separated into four different molecular weight fractions (30 kDa) which were screened for inhibitory activities against cancer cell growth. The >30-kDa fraction inhibited cell growth more than the other fractions. We separated crude polysaccharide (CPS) from the >30-kDa fraction to show that CPS increased DNA fragmentation, apoptotic body, and apoptotic cells with hypodiploid DNA contents in HL-60 cells. This indicates that CPS suppressed the growth of cells through apoptosis. The CPS gradually increased the expression of pro-apoptotic Bax and led to the activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase. The CPS was 40.85% fucose, 27.24% galactose, and 12.99% glucose, as analyzed by bio-liquid chromatography. These findings suggest that apoptosis effect can be mediated by CPS in HL-60 cells.