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

Asplenium trichomanes was used as an expectorant, anti-cough remedy, laxative, emmenagogue, abortifacient and for irregular menses.

To investigate the in vitro estrogenic activity of Asplenium trichomanes extracts and isolated compounds and their ability to activate ERalpha and ERbeta.

Leaves infusion (IF), decoction (DC) and methanol extract (ME) were prepared. MCF7/EREluc cell line which expresses endogenous ERalpha, and SK-NBE cells transiently transfected with the estrogen receptors (ERalpha and ERbeta) were used for the estrogenic activity assays. Phytochemical 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.

IF and ME were active in our MCF7 model; selectivity for the ERbeta 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 ERbeta receptor although with a moderate activity compared with 17-beta-estradiol.

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.