Chromosome Breakage by Pyrrolizidine Alkaloids and Modification of the Effect by Cysteine

Abstract

The author has studied the cytological effect, in onion root tips, of 6 pyrrolizidine alkaloids already known to be hepatotoxic in mammals and mutagenic in Drosophila. A comparative analysis of the effect of treatments with solutions of identical concentrations (3.2, 1.6 and 0.8 × 10^—3M/1) and for identical durations (24-hour treatment followed by one, two and several days of recovery into water) has shown that: Investigations on possible protective effects have shown that cysteine, when used in simultaneous treatments with lasiocarpine and monocrotaline, can riduce as much as 85% the chromosomal damage induced by the two alkaloids. The data obtained seem to offer indications of a lack of correlation between toxic effect and chromosome breaking effect in pyrrolizidine alkaloids.