In vitro estrogenic activity of Asplenium trichomanes L. extracts and isolated compounds

Ethnopharmacological relevance: Asplenium trichomanes was used as an expectorant, anti-cough remedy, laxative, emmenagogue, abortifacient and for irregular menses. Aim of the study: To investigate the in vitro estrogenic activity of Asplenium trichomanes extracts and isolated compounds and their ability to activate ER alpha and ER beta. Materials and methods: Leaves infusion (IF), decoction (DC) and methanol extract (ME) were prepared. MCF7/EREluc cell line which expresses endogenous ER alpha, and SK-NBE cells transiently transfected with the estrogen receptors (ER alpha and ER beta) were used for the estrogenic activity assays. Phytochernical investigations were performed (CC, HPLC, etc.) and structure of isolated compounds were achieved on the basis of 1D and 2D NMR techniques and HR-MS spectrometry. Results: IF and ME were active in our MCF7 model; selectivity for the ER beta receptor was observed in the SK-NBE test. Two new phenol derivatives, 4-vinyl-phenol-1-O-[alpha-L-rhamno(1 -> 6)-beta-d-glucopyranosyde] (1) and kaempferol-3-O-alpha-[2'acetyl]-arabinofuranosyl-7-O-alpha-L-rhamnopyranoside (2) were isolated with six known compounds (3-8). Compounds 2-4, 7 and 8 showed selectivity for the activation of the ER beta receptor although with a moderate activity compared with 17-beta-estradiol. Conclusion: Further investigations about the estrogenic effects of this plant are needed but our data can, at least in part, explain some of its traditional use as emmeagogue. (C) 2009 Elsevier Ireland Ltd. All rights reserved.