Furocoumarin Content of Fennel-Below the Safety Threshold.

Furocoumarins are known for their phototoxic and potential carcinogenic effects. These types of compounds have previously been reported from fennel ( Mill.), a widely used medicinal plant and spice; however, no reliable quantitative data are available on the occurrence of these compounds in fennel fruits. For the first time, we report a comprehensive analysis of fennel fruit samples of different origins, representing a wide range of accessions for their furocoumarin content. Psoralene, 5-methoxypsoralene (bergapten), and imperatorin contents of 33 fennel samples were analyzed using a sensitive liquid chromatography-mass spectrometry (LC-MS) method. When applied at the highest therapeutic dose described in the monograph issued by the European Medicines Agency, the furocoumarin content of the fruits ranged up to 1.22 μg/d, which is below the most restrictive recommendations. Based on our findings, fennel consumption can be considered as safe, at least based on its low furocoumarin content.