Cytotoxicity and Antitumor Properties of A Marine Compound on Cancer Cells (HESA-A)

The lack of specificity for tumor cells, which is associated with conventional cancer chemotherapy, is the main cause of failure of a new anticancer agent. Therefore, majority of the currently available anticancer drugs are designed to have selective toxicity to rapidly dividing cells. Among these agents and the focus of many studies are compounds obtained from natural products with high therapeutic index. In this study the cytotoxicity of HESA-A (a marine biological compound) was evaluated on cancer and normal cells.
HESA-A was dissolved in normal saline (pH 1.5), shacked for 30 minutes and filtered. Prior to its use, this stock solution (0.8 mg/ml, pH 7.4) was sterilized using 0.22 microbiological filters and diluted to final concentrations of 0.4, 0.2, 0.1 and 0.05 mg/ml. 180 l of cells (MDA-MB-468, HepII, Hela as cancer cells; L929 and McCoy as normal cells) were grown in completed RPMI1640 and seeded in 96 well micro plates at a concentration of 1-5 x 104 cells/ml. After their incubation for 24 hours, 20 l of different concentrations of HESA-A was added and cells were further incubated for 72 hours. Using MTT assay, percent cell survival was determined by ELISA at 540 nm. Doxorubicin was used as a positive control.
HESA-A (0.1 mg/ml) reduced the number of viable MDA-MB-468 cells to less than 50%. For Hela and HepII cells the IC50's were 0.2 and 0.4 mg/ml, respectively. In normal cells IC50 was not obtained at any given concentration. Therefore these results suggest that HESA-A selectively and in a concentration dependent manner inhibits the growth of cancer cells.