Objective: The aim of the study was to determine the strength of the Eriocaulon cinereum R.Br plant against breast cancer cells (MCF7) and cytotoxicagainst Vero cells.Methods: E. cinereum R.Br was taken from the province of Bangka Belitung and then extracted in stages with n-hexane, ethyl acetate, and methanol.Then, the ethyl acetate extract was fractionated using the vacuum liquid chromatography method with dichloromethane and ethyl acetate solvents.Sample was tested for MCF-7 cells and Vero cells using the MTT method (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). The dataobtained is analyzed by probit SPSS.Results: The results of this study showed that the best IC50 extract was ethyl acetate extract with an IC50 value of 450.31 μg/ml. Then, ethyl acetateextract produced dichloromethane fraction with IC50 value of 443.52 μg/ml and ethyl acetate with IC50 value of 214.75 μg/ml. Ethyl acetate fractionwas also tested against Vero cells to see cytotoxic against normal human cells with IC50 679.11 μg/ml

Traditionally, some People from bangka belitung has consumed Eriocaulon cinereum R.Br as an anticancer drug. Aims of this study is to determine the potential of cytotoxicity of Fraction of Ethyl Acetate and Dichlorometane against T47D cell. Fractionation using Vacuum Liquid Chromatography (VLC) method. MTT assay method was used on evaluating the citotoxic activity. The fraction of dichloromethane performed high activity as a chemopreventive agent with IC50 score was 131,921 µg/ml to T47D and 413,042 µg/ml cells to vero cell whereas for ethyl acetate fraction performed lower activity as chemopreventive agent with IC50 score was 531,808 µg/ml to T47D and 679,114 µg/ml to vero cell). Phytochemical tests showed that the dichloromethane fraction contains phenolic, steroid and terpenoid compounds. While ethyl acetate fraction contains alkaloids, flavonoids and terpenoids. These compounds have activity on cancer cells through apoptotic mechanisms. The results showed the excellent potential of this plant in killing breast cancer cells.