Detection of dehydropyrrolizidine alklaoids in honey, pollen, eggs and the associated Senecio species

Abstract

1,2-Dehydropyrrolizidine alkaloid (DHPAs) exposure in humans is most often via contamination of a primary food source such as in the co-harvesting of grains. More unknown is the potential for long term, low level exposure in foods, including pollen and honey, as well as eggs, milk and, perhaps, meat. Two such cases are presented here. First is the detection of DHPAs in honey and pollen from select experimental hives near fields infested with Senecio madagascariensis on the island of Hawaii. DHPAs concentration in honey from the hives ranged from 0.10 µg/g – 3.22 µg/g total alkaloid. No DHPAs were detected in honey from hives physically isolated from S. madagascariensis. Alkaloids were detected in two of four commercial samples at concentrations of 0.04 – 0.09 µg/g. Pollen contained much higher concentration of DHPAs in the range of 33.5 – 136.7 µg/g total alkaloids. Secondly, we report on an experiment to investigate the effect of dietary supplementation of chicken feed with Crotalaria pallida seeds during a 35 day feeding of commercial laying hens. Eggs collected during the 35 days of the treatment feedings contained usaramine at concentration range from 0.29 – 0.89 µg/g (dry egg matter). Seven days after treatment the concentration decreased to 0.009 – 0.043 µg/g usaramine.