Origanum majorana essential oil decreases lung tumor growth and metastasis in vitro and in vivo

Current targeted- and immuno-therapies have prolonged the overall survival of non-small cell lung cancer (NSCLC) patients by few months in a small percentage of patients responding to these treatments. This situation has prompted us to investigate the anticancer potential of the Origanum majorana Essential Oil (OMEO). In this pre-clinical study and using two major human NSCLC, namely A549 and LNM35, we demonstrated that OMEO significantly decreases the viability of these cells and the growth of their pre-formed colonies in vitro in a concentration-dependent manner and partly via the induction of caspase 3/7-dependent cell death and downregulation of survivin. Moreover, OMEO significantly slow down the growth of A549 and LNM35 tumor xenografts in the CAM and in nude mice models in vivo. Furthermore, OMEO significantly reduces in vitro A549 and LNM35 cancer cell migration and invasion, and the incidence and growth of lymph nodes metastasis in vivo in nude mice xenografted subcutaneously with the highly metastatic LNM35 cells. Three months of treatment of mice with OMEO did not affect blood, kidney, and liver functions. Our study demonstrates that OMEO is a safe and robust anticancer option.