Transfer of orally administered [3H]seneciphylline into cow's milk

The presence of pyrrolizidine alkaloids in dairy products could pose a hazard to human health. To investigate the transfer into cow's milk, a single dose of 1 Mg of [3H]seneciphylline/kg of body weight was given orally to a dairy cow. The appearance of radioactivity derived from this compound was monitored in the blood and milk. Calculated as seneciphylline, over 100 ng/mL was found in the blood during the first 18h. After 54 h, 11 ng/mL was still present. Alkaloid levels were similar in milk. After 64 h, the concentration was still at 5 ng/mL. In total, 0.16% of the dose was excreted in the milk. In the liver, 40 ng/g (0.06% of the dose) was found 3 weeks after treatment. In addition to unchanged seneciphylline and retronecine, N-oxides were detected in the milk as metabolites (11.2% at 27 h). The results indicate that the highest possible concentration of seneciphylline in the milk of unaffected cows can hardly exceed 10-20 microgram/L