GENOTOXIC EFFECTS OF KARWINSKIA HUMBOLDTIANA TOXIN-T-514 IN PERIPHERAL-BLOOD LYMPHOCYTES

Toxicity by Karwinskia humboldtiana, a Rhamnaceae plant, has been asse ssed in a number of studies. four dimmeric anthracenones, named T-496, 7-514, T-516 and 7-544 for their molecular weight, have been isolated from this plant. T-514, in particular, has been shown to be toxic to liver and lung as well as to tumoral cell lines, preferentially to tho se from liver tumors. For this reason it has been suggested that the t oxin could be used as an antineoplastic agent. The present study was p erformed to characterize the biological activity of T-514 as a potenti al cytostatic and genotoxic agent. Peripheral blood lymphocytes in cul ture were used as a test system, where chromosomal aberrations and sis ter chromatid exchanges were scored in order to evaluate genotoxicity, and mitotic index and cell proliferation kinetics were used as parame ters for cytostatic and cytotoxic ability. Genotoxicity to lymphocytes was negative. However, proliferation was affected by the toxin, demon strating a cytostatic activity independent of genotoxic damage.