Estrogenicity of essential oils is not required to relieve symptoms of urogenital atrophy in breast cancer survivors

Research output: Contribution to journalArticle

  • External authors:
  • Bertram Kholer
  • Jacqui Stringer
  • Lily Novak Frazer
  • Keely Young
  • Giorgia Zucchini
  • Anne Armstrong

Abstract

Background: Urogenital atrophy (UA) is a common treatment-limiting side effect of endocrine therapies. Topical estrogen is effective but systemic absorption may counter aromatase inhibitor efficacy. Numerous complementary approaches are marketed for use in UA without rigorous testing of their estrogenicity. We tested multiple essential oils in cancer cell growth and estrogen reporter assays in vitro and assessed clinical outcomes with the essential oil pessaries (EOP) in breast cancer survivors with UA.
Methods: Effects on cell growth were tested in hormone dependent (MCF-7) and independent (MDA-MB-231) cell lines using the sulforhodamine-B assay. An estrogenic response element (ERE) luciferase reporter assay was used to assess estrogenicity directly. Antifungal activity against two common pathogenic yeasts was assessed using standard microdilution methods. EOPs were offered to breast cancer survivors with symptomatic UA and the service evaluated using serial questionnaires.
Results: Two essential oils, Cymbopogon martinii and Pelargonium graveolens, demonstrated marked estrogenicity, stimulating ER+ cell growth and ERE-luciferase reporter activity to levels seen with premenopausal estradiol concentrations. Additional oils were screened for estrogenicity and Lavandula angustifolia and Chamaemelum nobile identified as non/minimally estrogenic. The antifungal activity of this combination of oils was confirmed. A second cohort of breast cancer survivors with UA received the second generation EOP with comparable improvement in symptom scores suggesting that estrogenicity may not be required for optimal therapy of UA.
Conclusion: Certain essential oils demonstrate profound estrogenicity and caution should be exercised before their use in breast cancer survivors. Our minimally estrogenic pessary will be formally tested in clinical trials.

Bibliographical metadata

Original languageEnglish
JournalTherapeutic Advances in Medical Oncology
Volume10
Early online date2 Apr 2018
DOIs
Publication statusPublished - 2018

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