Persistence of echimidine, a hepatotoxic pyrrolizidine alkaloid, from honey into mead

Honey produced by bees foraging on Echium plantagineum is known to contain dehydropyrrolizidine alkaloids characteristic of the plant. Following a prolific growth of E. plantagineum in the wake of Australian bushfires, two samples of mead, a fermented drink made from honey, and the honey used to prepare the mead were analyzed for the presence of Echium-related dehydropyrrolizidine alkaloids. HPLC–esiMS and MS/MS analysis of the alkaloidal fractions obtained using strong cation exchange, solid phase extraction unequivocally confirmed the presence of echimidine, a major hepatotoxic dehydropyrrolizidine alkaloid produced by E. plantagineum, in the honey (780 ng/g) and in the subsequent mead samples (236–540 ng/mL). The results from this limited, and specifically targeted sample set, while not indicative of the extent of the presence of echimidine (or other dehydropyrrolizidine alkaloids) in meads, reinforce the need for a wider survey and perhaps subsequent routine monitoring to determine the potential contribution to long-term, low-level or intermittent exposure to these toxic alkaloids and consequent chronic disease development.