1998 Volume 21 Issue 4 Pages 386-389
The selective cytotoxic activity of extracts from two marine green algae, Cladophoropsis vaucheriaeformis and Halimeda discoidea, was examined via a dose response assay against mouse leukemia L1210 cells and normal NIH-3T3 cells. The MeOH-extract from C. vaucheriaedormis showed selective cytotoxicity to L1210 cells at concentrations ranging from 50 to 100 μg/ml. In particular, the greatest selectivity for cytotoxic activitiy was found at the concentration of 50 μg/ml, at which the growth of L1210 cells was inhibited completely and that of NIH-3T3 was not affected at all.However, MeOH, extracts from the red alga Laurencia okamurae and brown alga Dictyopteris undulata, which displayed non-selective cytotoxicity in our previous screening program, did not show similar selective cytotoxicity at any concentrations tested.These results indicate that the marine green alga C. vaucheriaeformis may contain a unique antitumor substance with selective cytotoxic activity against L1210 cells. Our results also suggest that this active substance might be of low molecular weight and therefore MeOH-soluble.