Induction of micronuclei by alkaloids extracted from Senecio brasiliensis and stored for 23 years

In the present study, we report the results of an investigation on pyrrolizidine alkaloids extracted from Senecio brasiliensis (Sprengel) Less., which were stored for more than 23 years under variable conditions of temperature and humidity and exposed to light. Both the crude alkaloid (integerrimine+retrorsine+impurities) and pure integerrimine conserved the ability to induce acute toxicity in mice, leading to the death of the animals in less than 24h. The alkaloids also conserved the potential to induce significant increases in micronucleus frequencies in polychromatic erythrocytes of mouse bone marrow compared to the negative control. The administration of alkaloids to lymphocyte cultures blocked with cytochalasin-B showed no significant increase in micronucleus frequency in binucleated cells, probably due to the lack of a metabolic activation mechanism. However, an antimitotic effect was observed.