GENOTOXICITY OF TETRODOTOXIN FROM PUFFER FISH TESTED IN ROOT-MERISTEMCELLS OF ALLIUM-CEPA L

Tetrodotoxin (TTX) extracted and purified from puffer fish Arothron ni gropunctatus was tested for genotoxicity employing the root meristem c ells of Allium cepa as the assay system, The genotoxicity endpoints in vestigated were mitotic index (MI), meta-anaphases with spindle aberra tions, interphases with micronuclei (MNC) and sister chromatid exchang es (SCE) in metaphase chromosomes, The results demonstrated that TTX i nhibited mitosis at concentrations of greater than or equal to 30 mu M as evident by the fall of MI, but failed to induce MNC at significant levels at any of the concentrations tested (10-100 Mu mu M). TTX was thus proved to be neither clastogenic nor aneugenic in the present stu dy, It was, however, noteworthy that TTX at far lower concentrations, 0.1-5.0 mu M, significantly enhanced the frequencies of SCE which indi cated possible interference of the toxin in DNA replication and repair .