Foeniculum vulgare and Pelargonium graveolens Essential Oil Mixture Triggers the Cell Cycle Arrest and Apoptosis in MCF-7 Cells

Background: Fennel (Foeniculum vzilgare) and rose geranium (Pelargonium graveolens) oils are known for their various biological effects including anticancer properties. Objective: This study aimed to evaluate the anticancer mechanism of fennel and geranium oils combined treatment on MCF-7 cells. Methods: The GC-MS method for essential oil characterization as well as the in vitro cytotoxicity, morphological changes, real-time PC'R and immunocytochemical investigation for apoptosis-related markers, in addition, to flow cytometric cell cycle distribution analysis were done. Results: The major constituents of both essential oils were anethole (55.33%) and estragole (11.57%) for fennel essential oil. However, cintronellol (34.40 %) and geraniol (8.67 %) were identified in geranium oil. The results revealed an IC50 so of 220 +/- 5.7 and 60 +/- 2.1 mu g/ml for fennel and geranium oils, respectively. The mechanistic anticancer properties were investigated throughout the 70, 50, and 25 mu g/ml of oils mixture. The marked apoptotic morphology and the flow cytometric cell cycle distribution analysis in addition to the levels of apoptosis-related makers such as p53, caspase-3, mir-21, mir-92a, Bc1-2, and ki-67 confirmed that fennel and geranium oils combination induced cell cycle arrest and apoptosis in MCF-7 cells. Moreover, the oils mixture did not exert any significant (P<0.01) toxicity on normal human peripheral blood lymphocytes in vitro. Conclusion: The findings showed that the mixture of oils exerted selective cytotoxicity towards MCF-7 cells through induction of cell cycle arrest and apoptosis which may be triggered by the synergistic effect between the active ingredients of fennel and geranium oils.