Bioprospecting Icelandic liverworts for anticancer activity

Liverworts (Marchantiophyta, Hepaticae) belong to the bryophytes and comprise of about six to eight thousand species which are distributed everywhere in the world. Although being the structurally most primitive of the terrestrial plants they produce a complex array of secondary metabolites, including a number of mono- sesqui- and diterpenoids and also aromatic compounds like bibenzyls and bis (bibenzyls). Studies have demonstrated that several of these compounds possess a wide range of interesting biological activities, for instance inhibitory activity against cancer cells. Herein, the inhibiting effects of extracts and fractions from two different Icelandic liverworts were investigated on cancer cell-lines in vitro. Chiloscyphus pallescens and Marchantia polymorpha were collected in Iceland. Diethyl ether extracts were prepared and they were further fractionated on VLC (Vacuum Liquid Chromatography) with a n-hexane:ethyl acetate gradient. The inhibitory effects of the extracts and selected fractions were tested in four concentrations 80, 40, 20 and 10µg/ml, on the cancer cell-lines MCF-7 and T47D. Results were obtained as% viable cells by crystal violet staining. Extracts and fractions from both liverwort species demonstrated dose-dependent inhibitory effects onto cell growth, viability and colony formation ability of the cancer cells in vitro. One fraction from each liverwort showed the highest activity with approximate IC50 20µg/ml. Bioguided isolation of active constituents from these fractions is in progress.