The enigmatic Silphion: A phytochemical perspective

Silphion, a ferulaceous plant endemic to the Libyan steppe, produced the most valuable spice of the Greco-Roman world, and is considered the first case of man-related plant extinction in written history. Based on ancient sources and iconographic documentation, Silphion was identified as a plant from one of the genera Ferula, Margotia, Thapsia or Cachrys, and has been at the center of recent debates on its controversial use as a contraceptive and its alleged rediscovery in a remote Anatolian area. The identification of Silphion will be discussed combining botanical considerations with current knowledge on the phytochemistry and bioactivity of its various modern candidates. Ambiguities and inconsistencies in the ancient sources complicate the identification of Silphion with a modern plant species. Based on morphological fit, Margotia gummifera (Desf.) Lange seems its closest living relative, as suggested already in the early 19th century by the German botanist Link. A greedy land management policy, presumably exacerbated by previous overexploitation, was blamed by historical sources as the ultimate cause of extinction of Silphion in the first century AD. The pre-extinction documentation does not support its use as a contraceptive or as an aphrodisiac, rather showing that Silphion was basically a luxury culinary delicacy, only occasionally used for medicinal purposes. Later references to an abortifacient activity could actually refer to asafoetida (Silphium parthicum), its culinary post-extinction replacement from various Ferula species, for which ethnopharmacological association with sexuality could have a foundation, due to the occurrence of the powerful estrogenic compound ferutinin (35a).