Cytotoxic effects of essential oils from four Lippia alba chemotypes in human liver and lung cancer cell lines

Essential oils (EOs) from aromatic plants contain molecules that can interfere with diseases such as cancer and are considered attractive because of their widespread use, good bioavailability, low toxicity and affordable cost. EOs from Lippia alba (LaEOs) manifest intraspecific chemical differences in its composition - defined as chemotypes - and is notable for the chemical diversity of their volatile secondary metabolites. We evaluated LaEOs chemotypes cytotoxicity on human cancer culture cells and investigated the mechanisms involved in tagetenone (ta) chemotype cytotoxicity. It exhibited selective cytotoxicity against HepG2 and A549 cells. The mechanism involved cell cycle arrest and apoptosis induction. Tagetenone chemotype (LaEOta) treatment caused 3-hydroxy-3-methylglutaryl-coenzyme A reductase decrease and profound cholesterogenesis inhibition with farnesyl pyrophosphate redirection towards other end products, such as ubiquinone. This work contributes to a clearer understanding of mechanisms of action of LaEOta, thus suggesting that the use of that tagetenone chemotype could provide significant health benefits as a chemopreventive and/or chemotherapeutic agent.