The cytotoxicity of the brown alga Sargassum siliquastrum on human cancer cells (AGS, HT-29, HT-1080, and MCF-7) was investigated. Bioassay-guided fractionation of the crude extracts showed that the 85% aq. methanol (MeOH) fraction was the most toxic. Seven known meroterpenoids (1-7) were isolated from this cytotoxic fraction. Each compound was evaluated for its cytotoxic effect on human cancer cells. Compounds 1, 2, and 4 showed strong cytotoxicity against AGS, HT-29, and HT-1080 cell lines, with IC50 values ranging from 0.5 to 5.7 μg/mL.
Cytotoxicity of Meroterpenoids from Sargassum Siliquastrum against Human Cancer Cells