Seaweed polysaccharides with anticancer potential

Abstract

Abstract Aqueous extracts from 12 species of Hong Kong seaweeds were screened for their antiproliferative potential on HL-60 and MCF-7 cell lines. Eight seaweeds exhibited selective antiproliferative activity on HL-60 cells, while 10 species possessed some effect on MCF-7 cell line. Two brown seaweeds, Hydroclathrus clathratus and Padina arborescenos, had a higher inhibitory effect on the growth of both cancer cell lines than the others and were less toxic to normal cells. The extract of H. clathratus (Hy) caused morphological alteration of MCF-7 cells when they were treated at the beginning of incubation. Some polysaccharide fractions isolated and purified from Hy had antiproliferative activity on both HL-60 and MCF-7 cell lines. Furthermore, all of these fractions, including the crude extract, had varying degrees of antioxidant activity. In vivo antitumor tests using Sarcoma 180 tumor-bearing BALB/c mice showed that the fraction H3-a from H. clathratus had the best effect in suppressing tumor growth in the treated mice.