SELECTIVE ANTITUMOR-ACTIVITY IN-VITRO FROM MARINE-ALGAE FROM JAPAN COASTS

In vitro selective antitumor activity was tested as a general screenin g parameter for biologically active substances from a wide range of sp ecies of seaweed, 1446 samples of 306 species of marine algae from Jap an's coasts. The algae extracts were prepared successively first by ph osphate buffered saline (PBS) and then by methanol, and then tested fo r in vitro selective antitumor activity against murine lymphoid leukem ia L1210 cells and for low cytotoxic activity against NIH-3T3 normal c ells. Strong cytotoxic activity against L1210 tells was found in 47 sp ecies of algae, also showing similar cytotoxicity to mouse NIH-3T3 nor mal cells. However, four species of green algae showed strong activity specifically against L1210 cells, with low cytotoxicity to normal cel ls. Such selective activity was conspicuous in two brown and two green algae extracts. Tn particular, methanol extracts from the green alga, Cladophoropsis vaucheriaeformis, exhibited high viability (86%) to no rmal cells, showing selective cytotoxicity to tumor cells. This alga e xtract was not cytocidalic, but cytostatic against L1210 cells. Furthe rmore, the results of a cytotoxic spectrum test with 9 cell lines incl uding those of L1210 and NIH-3T3 demonstrated that this extract acted strongly only against leukemic cell lines L1210 and P388.