Presence of pyrrolizidine alkaloids in honey and the effects of their consumption on humans and honeybees. Review

Honey produced by honeybees (Apis mellifera L.) is a natural food whose composition depends on the floral origin, the geographical region and the climate where it is produced. Honeybees produce honey from the nectar of flowers, so honey may have secondary metabolites such as pyrrolizidine alkaloids, which are produced by some plants as defense mechanisms against insects and herbivorous animals. Pyrrolizidine alkaloids are toxic to humans and honeybees since they are mutagenic, carcinogenic and hepatotoxic to humans, and in honeybees they produce deterrent effects on feeding, reduce trophallaxis among worker honeybees and can cause the death of honeybees in a colony. The objective of this paper was to review the origin and chemical characteristics of pyrrolizidine alkaloids, the presence of these compounds in honey, their toxicity to both humans and honeybees, and the food regulation that establishes the limits of daily consumption of pyrrolizidine alkaloids.