Turbinaria deccurrens Bory contains bioactive compound that is beneficial for health. Turbinaria deccurrens Bory is one of many species of brown seaweed that grows in Indonesian marine life and has been known to have cytotoxic activity. The aim of this study is to determine fucoxantin content and the cytotoxic activity of extract and fraction T. decurrens on colon cancer cell lines. Cytotoxic assay of ethanolic extract, n-hexane, ethyl acetate and ethanolic fractions against HCT-116 by MTS assay using Cell Counting Kit-8 (CCK-8). Fucoxantin content in extract and fraction were analyzed using Reversed-Phase High Performance Liquid Chromatography (RP-HPLC) analysis. Extract and fraction of T. decurrens contain fucoxanthin with the highest content of fucoxanthin was in ethyl acetate fraction. CCK-8 assay showed that extract, n-hexane and ethyl acetate fraction inhibited the growth of HCT-116. Brown seaweed Turbinaria decurrens was potential as an anticolon cancer agent.

KEY WORDS: Brown seaweed; Turbinaria decurrens; Colon cancer; HCT-116; Fucoxanthin.