Ferns and LycopodsA Potential Treasury of Anticancer Agents but Also a Carcinogenic Hazard

Many species of seedless vascular plantsferns and lycopodshave been used as food and folk medicine since ancient times. Some of them have become the focus of intensive research concerning their anticancer properties. Studies on the anticancer effect of crude extracts are being increasingly replaced by bioactivity-guided fractionation, as well as detailed assessment of the mechanism of action. Numerous compoundsespecially flavonoids such as amentoflavone and protoapigenone, and also simpler phenolic compounds, steroids, alkaloids and terpenoidswere isolated and found to be cytotoxic, particularly pro-apoptotic, or to induce cell cycle arrest in cancer cell lines in vitro. In in vivo experiments, some fern-derived compounds inhibited tumour growth with little toxicity. On the other hand, many fernsnot only the well-known Bracken (Pteridium)may pose a significant hazard to human health due to the fact that they contain carcinogenic sesquiterpenoids and their analogues. The objective of this review is to summarise the recent state of research on the anticancer properties of ferns and lycopods, with a focus on their characteristic bioactive constituents. The carcinogenic hazard posed by ferns is also mentioned. Copyright (c) 2013 John Wiley & Sons, Ltd.