Terrein from Aspergillus terreus Induced Cytotoxic and Nuclear Changes on Human Colon Cancer COLO205 Cells

Colon cancer is the most common cancer worldwide. Recently, natural products have been used for the treatment of cancer are becoming an important research area for drug discovery. Terrein, a fungal metabolite derived from Aspergillus terreus, has shown to have a variety of biological activities that exhibit selective anticancer activity including colon cancer. However, cytotoxic effects of terrrein against human colon cancer cell lines have never been studied before. Therefore, the present study observed the cytotoxic effects of terrein by using the MTT assay. The sensitivity was evaluated by comparing the effect to COLO 205 cells with vero cells for 24 h. The results of MTT assay showed that terrein was cytotoxic to COLO 205 with IC50 at 0.05 mM, but not to normal Vero epithelial cell line. The induction of dead cells was further investigated by observing the cellular morphology of nuclei using Hoechst 33342 staining, a DNA specific dye. The results showed increasing treated cancer cells in nuclear condensation and fragmentation with 0.05, 0.15, 0.2, 0.25, 0.3 mM at 6 h by observing under the phase contrast inverted microscopy. These data supported that the mode of dead cell induction of terrein, possibly activated via apotosis mechanism. Terrein is an interesting compound that might be a potential candidate for colon cancer treatment. However, investigation through the mechanism of action is needed.