Cytotoxic essential oils from Eryngium campestre and Eryngium amethystinum (Apiaceae) growing in central Italy

Eryngium campestre and E. amethystinum are thorny herbs belonging to the Apiaceae family and spontaneously growing in stony pastures and dry meadows, preferentially on calcareous substrates. In the Mediterranean countries, these plants have been used as a food or traditional remedies to treat various ailments. In the present work, we have analysed the chemical composition of the essential oils distilled from the aerial parts by GC-FID and GC-MS, and evaluated their cytotoxic effects on a panel of human cancer cells, namely A375 (human malignant melanoma), MDA-MB 231 cells (human breast adenocarcinoma) and HCT116 cells (human colon carcinoma), by the MTT assay. Furthermore, the Eryngium essential oils were evaluated for antioxidant and acetylcholinesterase (AChE) activities. The two essential oils were rich in sesquiterpene hydrocarbons, with germacrene D as the major compound, accompanied by allo-aromadendrene, -elemene, spathulenol and ledol. They resulted highly cytotoxic on the tumor cells, with IC50 values (1.65-5.32 and 1.57-2.99 µg/ml for E. amethystinum and E. campestre, respectively) comparable or close to those of the anticancer drug cisplatin. The E. amethystinum essential oil exhibited a moderate antioxidant activity whereas that of E. campestre a weak AChE inhibition.