Essential oil metabolites can regulate adrenal androgen production by inhibition of CYP17A1 activities

Endocrine-disrupting chemicals (EDCs) can affect human steroid metabolism. Previous clinical case reports have shown that some Essential Oils (EOs) like lavender oil and tea tree oil may act as potential EDCs and are linked to prepubertal gynecomastia in boys and premature thelarche in girls due to regular exposure to lavender based fragrances among Hispanic population. These studies suggested role of EOs in steroid metabolism in humans. We have screened a range of EO metabolites for effects on androgen production by CYP17A1. For preliminary screening, human adrenal NCI H295R cells were treated with 10 µM of test compounds for 24 hours. The test compounds had been extracted and purified from natural resources and are found as major components in EOs. For CYP17A1 activity, the conversion of radiolabelled substrate, 17-Hydroxy-pregnenolone to Dehydroepiandrosterone was determined using tritiated water release assay. Eucalyptol, Dihydro-β-Ionone, (-)-α-pinene were extracted from eucalyptus, rose and pine resin. Out of about 50 test compounds, eucalyptol, Dihydro-β-Ionone & (-)-α-pinene showed 20% to 40% inhibition of DHEA production. Rest of the compounds showed either no or low inhibition. Some compounds were also tested for effects on CYP19A1 (aromatase) activity where upto 30% inhibition was observed. EOs are often used in various beauty and hygiene products as they have few known side-effects. However, prolonged exposure to these products may result in steroid imbalance. Due to their anti-androgenic activity, these compounds should be studied further as chemical leads for the treatment of hyperandrogenic disorders such as Prostate cancer and Polycystic ovary syndrome.