Cytotoxicity and hemolysis by an extract of the sponge Pachymatisma johnstonii

In vitro cytotoxicity on human rhinopharynx KB cells, as well as hemolytic activity on human erythrocytes, was produced by an aqueous extract of the sponge Pachymatisma johnstonii. Optimum temperature and pH were the same for both activities (37 degrees C, pH 5). Moreover, after partial purification, the compounds involved were found in the same chromatographic fraction. These compounds were sensitive to treatment with dithiothreitol, but not with papain or trypsin. Cytotoxicity was destroyed by heat, whereas hemolysis subsisted after the extract was heated to 100 degrees C.