Marine organisms such as ascidians, sponges and soft corals, containing symbiotic
microorganisms are a rich source of bioactive compounds. This study examined the cytotoxic
potential of two ascidians found in the coastal waters of Tuticorin. The ascidians samples
Didemnum psammatode and Phallusia arabica were extracted in methanol and ethanol. The
crude extracts were tested for cytotoxicity using the brine shrimp lethality assay. The crude
methanol extract of compound ascidian indicated the highest activity with LC50 value of (106.965
μg/ml) and the ethanol extract of simple ascidian showed the lowest activity with LC50 value of
(227.055 μg/ml). Further studies are necessary for a better characterization of the active
principles of these extracts and a possible elucidation of the mechanisms of action.
