| abstract |
Disclosed is a method and a pharmaceutical composition for killing mammalian tumor cells by subjecting said cells to light in the presence of light-activatable tetrapyrrole, in which the improvement comprises treating said cells with a compound which inhibits the enzymatic conversion of protoporphyrinogen to protoporphyrin IX by protoporphyrinogen oxidase in said cells thereby causing a buildup of protoporphyrin IX in said cells. Also disclosed is a method for the production of protoporphyrin IX which comprises growing eukaryotic microalgae in the presence of a protoporphyrinogen oxidase inhibitor. |