Assessment of hormone-like activities in Ginkgo biloba, Elettaria cardamomum and Plantago ovata extracts using in vitro receptor-specific bioassays

Abstract

Medicinal plants are widely used for the treatment of diseases and for the development of new drugs. This study was designed to determine the presence of hormone-like activities dependent on the activation of human estrogen receptor alpha (hERa) and/or androgen receptor (hAR) in methanol extracts prepared from three medicinal plants historically and currently used for therapeutic purposes: Ginkgo biloba leaves (GBL), Elettaria cardamomum seeds (ECS) and Plantago ovata seeds (POS). After a solid–liquid extraction (SLE) step, their effects on hERa function were assessed in MCF-7 breast cancer cells using the E-Screen bioassay, and their ability to induce hAR-mediated reporter gene expression was evaluated using the androgen-sensitive stable prostatic PALM cell line. Unlike POS extracts, GBL and ECS extracts showed estrogenic (0.07 and 0.20 nM E₂Eq mg^–1, respectively) and anti-estrogenic (0.01 and 0.02 μM ICI182780Eq mg^–1, respectively) activities. ECS extracts evidenced androgenic activity (0.30 nM R1881Eq mg^–1) and POS extracts anti-androgenic activity (22.30 μM ProcEq mg^–1). According to these findings, these plant extracts may interfere with the endocrine system via one or more hormonal receptors, and further investigation is warranted into their role as endocrine disrupters in humans.

Graphical Abstract

Keywords:

• Ginkgo biloba leaves
• Elettaria cardamomum seeds
• Plantago ovata seeds
• E-Screen bioassay
• human androgen receptor (hAR)

Acknowledgements

The authors thank Richard Davies for editorial assistance.

Additional information

Funding

This research was supported by grants from the European Union Commission [CONTAMED FP7-ENV-2007-1-212502], the Spanish Ministry of Health [EUS2008-03574; FIS PI11/0610 and PI13/02406], and from the Andalusia Regional Government [Excellence Project P09-CTS-5488 and SAS PI-0513-2012].