Salvia officinalis for menopausal hot flushes: Towards determination of mechanism of activity and active principles
Herbal medicinal products are commonly used in alternative treatment of menopausal hot flushes. In a recent clinical study, Salvia officinalis tincture was found to reduce hot flush frequency and intensity (1). This study aimed at investigating the mechanism(s) responsible for the anti-hot flush activity of S. officinalis and determination of its active principle(s). The ethanolic tincture and its n-hexane, CHCl3 and aqueous EtOH subextracts were studied for in vitro estrogenic, selective serotonin re-uptake inhibition (SSRI) and acetylcholinesterase inhibition (AChEI) activities. No activity was observed in the SSRI or the AChEI assays at the highest test concentrations, whereas the aqueous EtOH subextract displayed estrogenicity in the ERLUX assay (EC50 64 µg/ml). Estrogenic activity-guided fractionation of this subextract identified luteolin-7-O-glucuronide (EC50 129 µg/ml) as the active component of the initial VLC fraction 4 (EC50 69 µg/ml). The most potent estrogenicity was tracked to a subfraction (18.104.22.168, EC50 0.7 µg/ml) obtained from the VLC fraction 7 (EC50 3 µg/ml). As this minor fraction (1.81 mg) could not be further purified, its constituents were characterised and quantified by both capillary NMR and UHPLC-PDA-TOF-MS to reveal luteolin-7-O-glucoside to be its major component. When the estrogenic activity of commercial luteolin-7-O-glucoside (EC50 0.44 µg/ml) was compared to that of the subfraction 22.214.171.124, they were almost identical. Hence, luteolin-7-O-glucoside appears to contribute significantly to the estrogenicity of the fraction. This study suggests the involvement of ubiquitous estrogenic flavonoids in the in vitro anti-hot flush effect of S. officinalis, a safe and commonly used herbal medicinal product during the menopause.
This project was financially supported by Bioforce AG, Switzerland.
 Bommer S, Klein P, Suter A. Adv Ther 2011, 6, 490 – 500.