Abstract: Rock shells, Thais clavigera, as one of the most popular seafood in Fujian Province, are proved to have pharmaceutical activities according to the traditional Chinese medicine records and the historical usage. However,
there are few public reports about the active components from the snail. In this paper, we isolated and screened the anti-tumor substances E-EA-2 from the rock shells. The main component of E-EA-2 was identified as 6-bromoisatine by means of HPLC and GC-MS. The cancer cell proliferations ( MCF-7 and QGY-7703 ) were significantly inhibited when the concentration of E-EIA-2 exceeded 40 g/cm3. E-EA-2 could induce PARP cleavage in QGY-
7703 cells. While the number of survival cancer cells obviously increased at presence of cell permeable pan caspase inhibitor Z-VAD. And cultured MCF-7 cells with E-EA-2 after 24h, cell nuclear shrinkage, loss of mitochondrial membrane potential and cell apoptosis were obvious. The IC50 of E-EA-2 was 46 ug/cm3 and 28g/cm3 to QGY-7703 and MCF-7, respectively. The anti-tumor eflects of E-EA-2 might be taken through promoting cell apoptosis.