Herbal medicinal products (HMPs) are widely used as an alternative to common hormone replacement therapy for the relief of menopausal symptoms [1]. It has been reported that menopausal women experienced a significant reduction of hot flushes during treatment with a HMP containing Salvia officinalis [2], but the mechanism underlying this effect has remained unknown. In order to obtain mechanistic insights into this biological effect, we investigated estrogenicity as a possible mode of action of a 66% ethanolic S. officinalis tincture as well three subextracts (n-hexane, CHCl3 and aqueous-EtOH) obtained by solvent-solvent partition of this tincture. Estrogenicity was evaluated using a reporter gene construct in the human breast cancer cell line (T47D-Kbluc) with luminescence as the endpoint [3]. While the tincture showed no apparent effect, the aqueous-EtOH subextract exhibited estrogenic activity with a half maximal effective concentration (EC50) value of 64µg/ml. Additionally, the inhibitory potential of the S. officinalis tincture and the subextracts against the cytochrome p450 enzyme (CYP) isoform 3A4 was assessed in a fluorescence based microtiter plate assay [4]. The tincture, the n-hexane and the CHCl3 subextracts were found to inhibit CYP3A4 moderately, whereas no CYP inhibition activity was detected with the estrogenic aqueous-EtOH subextract at concentrations under 70µg/ml. Although estrogenicity could not be identified in the S. officinalis tincture, the activity found in the aqueous EtOH subextract may contribute to the overall effects of the tincture for amelioration of menopausal symptoms.
Acknowledgements: Funding from Bioforce AG Switzerland is gratefully acknowledged.
References: [1]Geller, S. et al. (2005)J. Womens Health 14:634–649.
[2] De Leo, V. et al. (1998) Minerva Ginecol. 50:207–211.
[3] Wilson, V. et al. (2004) Toxicol. Sci. 81:67–77.
[4] Crespi, C. et al. (1997) Anal. Biochem. 248:188–190.
