ANTICANCER SUBSTANCE IN PIERIS-BRASSICAE

Extracts of the body fluid of Pieris rapae and Pieris brassicae, both common butterflies, are reported to show cytotoxic activity against hu man gastric carcinoma TMK-1 cells. When TMK-1 cells were treated with an extract from pupae of P. brassicae, the resultant morphological cha nges in dying cells were similar to those found for pupae of P. rapae. The extract of the former exerted dose-dependent cytotoxicity with th e IC50 value against TMK-1 cells at the 1/10(7) dilution. The cytotoxi c substance in the pupae of P. brassicae was found to be heat-labile, precipitated with ammonium sulfate and digested by pronase E and prote inase K. Thus, the anti-cancer principle present in the pupae of P. br assicae is suggested to be a protein, like the pierisin, anti-cancer p rinciple in P. rapae.