Photodynamic effects of hypocrellin A on three human malignant cell lines by inducing apoptotic cell death.

Hypocrellin A (HA), a lipid-soluble peryloquinone derivative extracted from the fungus Hypocrella bambusae, has been proved to be effective in treating many diseases. In this study, we have examined the photodynamic effects of HA on three different human malignant epithelioid cell lines, i.e., HIC, MGC-803 and HeLa cells. They all respond to photodynamic therapy (PDT) by committing apoptosis or necrosis evidenced by morphological changes, DNA fragmentation and a decrease of mitochondria dehydrogenase activity. The sensitivity order of the three cell lines to cytotoxicity by HA is HIC > MGC-803 > HeLa. The extent of apoptosis is also dependent on light dose, post-treatment time and cell type. Vitamin E can significantly protect cells against cell death, indicating that reactive oxygen species (ROS) play an important role in apoptotic or necrotic cell death. These results may be to some extent instructive for clinical cancer treatment.