Enhancing Cytotoxicity of Tamoxifen Using Oil.

Aromatherapy and plant-based essential oils are widely used as complementary and alternative therapies for various symptoms, including anxiety, mild mood disorders, and cancer-related pain. In a previous study, we developed an in vitro assay using immortalized hypothalamic neuronal cells (GT1-7 cells). In this study, we used this assay to investigate the effects of oil on the cytotoxicity of the oestrogen receptor (ER) antagonist: tamoxifen (TMX). The results showed that oil augmented TMX-induced cell death in a dose-dependent manner without directly reducing the viability of GT1-7 cells. Cotreatment with oil and ER agonist -estradiol (E2) attenuated the inhibition of GT1-7 cell growth. Moreover, oil and geraniol, a major constituent of oil, showed weak agonist activity on ER and ER with geraniol augmenting TMX-induced cell death similar to that observed in oil. Both compounds impair E2 activity. These data indicate that geraniol is an essential constituent of oil.