New insights into the mechanisms of French lavender essential oil on non-small-cell lung cancer cell growth

The essential oil of Lavandula dentata L. possesses sedative, antioxidant, antibacterial, antifungal, carminative, antidepressant, and cytotoxic properties. The aims of this study were to investigate the cytotoxic effects of L. dentata essential oil on Calu-3 lung cancer cells in both vapor and liquid phases, and to provide further insights into its cytotoxic mechanisms. Usual MTT, SRB, and DNA-PI assays were used for evaluating cytotoxicity. In addition, LDH, acridine orange with ethidium bromide, Hoechst 33342, propidium iodide, Rhodamine 123, and Annexin V analyses were performed to explore the cytotoxic mechanisms. Rhodamine 123 accumulation assay was used for evaluating P-glycoprotein inhibitory potential. L. dentata essential oil provided a significant reduction of cell viability for all cytotoxic experiments by reaching 84% of cytotoxicity in vapor phase and showed a time-dependent profile. Both necrosis and apoptosis were involved in Calu-3 cell death. However, necrosis appeared to be the dominant cell death pathway. L. dentata essential oil did not inhibit P-glycoprotein.