Dietary selenium status and pyrrolizidine alkaloid metabolism in vitro by rat liver microsomes

The effect of dietary selenium status on the metabolism of pyrrolizidine alkaloids (monocrotaline, and mixed pyrrolizidine alkaloid from Senecio jacobaea) by rat liver microsomes in vitro was studied. In two experiments, there was no difference in the rate of metabolism of alkaloid by microsomes from selenium deficient or selenium supplemented rats. Selenium deficiency was confirmed by measurement of erythrocyte glutathione peroxidase. Administration of excess selenium by i.p. injection did not affect alkaloid metabolism. It was concluded that dietary selenium status was unlikely to influence the metabolism of pyrrolizidine alkaloids.