Anti-cancer activity of rose-geranium essential oil and its bioactive compound geraniol in colorectal cancer cells

Abstract Essential oils are emerging as promising candidates in cancer therapeutics due to their various biological properties. This study investigates the anti-cancer effects of edible essential oils—Bergamot, Rose-geranium, Ginger, Turmeric, Myrrh, and Frankincense—on colorectal cancer cell lines, focusing on their impact on cell viability, molecular pathways, and anti-oxidant potential. Cell viability assays demonstrated dose-dependent inhibition of cancer cell growth, with rose-geranium essential oil showing the lowest IC50 values among those tested (0.37 µL/mL in HCT116 cells, 0.54 µL/mL in LoVo cells and 0.39 µL/mL in SW480 cells). Anti-oxidant activity showed that Ginger and Myrrh essential oils had the lowest EC50 values and highest Vitamin C Equivalent Antioxidant Capacity. Protein expression analysis revealed a significant decrease in oncogenic EpCAM protein and an increase in tumor suppressor proteins (p53 and NAG-1), with the most pronounced effects observed for rose-geranium oils. Geraniol, a primary component of rose-geranium essential oil, was further examined for its anti-cancer properties. Geraniol inhibited cell viability and spheroid formation in a dose-dependent manner, with significant effects on molecular markers such as NAG-1 and EpCAM expression. Antioxidant assays revealed that geraniol exhibited activity comparable to vitamin C. Furthermore, geraniol effectively enhanced NRF2-mediated antioxidant pathways, demonstrating comparable efficacy to the established NRF2 activator, quercetin. The transcript expression and promoter analyses demonstrated that geraniol regulates NAG-1 transcription. Finally, the in silico analysis indicates that geraniol’s anti-cancer effects may be mediated by the modulation of transcription factors involved in NAG-1 transcriptional regulation. These findings highlight the potential of edible essential oils, particularly rose-geranium and its active component geraniol, as promising therapeutic agents for colorectal cancer.