Mentha piperita essential oil exerts pro-oxidant effects both at the cytosol and at the mitochondria leading to apoptosis in Saccharomyces cerevisiae

• Published in: Planta Medica
• Main Authors: Ferreira, P, Cardoso, T, Ferreira, F, Fernandes-Ferreira, M, Piper, P, Sousa, MJ
• Format: Conference Proceeding
• Language: English
• Published: 30.10.2014
• ISSN: 0032-0943; 1439-0221
• DOI: 10.1055/s-0034-1394783

Mentha piperita is a widely distributed aromatic and medicinal plant from the Mediterranean flora and its essential oil has been shown to inhibit growth of several food spoilage yeast species [1], bacteria [2,3] and pathogenic fungi [4]. However, the mechanisms responsible for the observed cytotoxic properties have not been thoroughly investigated. In the present study, we have shown that M. piperita essential oil (MP-EO) induces cell death in Saccharomyces cerevisiae accompanied by reactive oxygen species (ROS) accumulation and nuclear condensation without extensive loss of plasma membrane integrity, suggesting the involvement of an apoptotic pathway. ROS accumulation plays an important role in mediating the toxic effects of the MP-EO and of its principal component menthol, with damage induced both at the cytosolic and mitochondrial levels. In fact, overexpression of SOD1 (copper-zinc-superoxide dismutase) and CTT1 (cytosolic catalase T) could increase resistance to both the essential oil and menthol, indicating that survival is limited by oxidative stress. The higher sensitivity of Δsod1 opposite to Δsod2 (manganese superoxide dismutase) mutants, conserved also in their respective respiratory deficient strains, Δsod1ρ- and Δsod2ρ- strains, further suggest that both agents can act as redox-cycling compounds and their effects do not depend on an active respiratory transport chain, although they are enhanced under respiratory conditions. Significant protein oxidative damage at mitochondria level does not seem to occur, as Grx5 p glutaredoxin did not display a protective role. On the contrary, the MP-EO seems to induce damage to the mitochondrial genome as it increased the frequency of respiratory deficient strains. Acknowledgements: This work was supported by FEDER through POFC – COMPETE and by Portuguese funds from FCT through the project PEst-OE/BIA/UI4050/2014. Keywords: Mentha piperita, essential oil, cell death, Saccharomyces cerevisiae, yeast, reactive oxygen species, superoxide dismutase, catalase References: [1] Araújo C, Sousa MJ, Ferreira MF & Leão C. (2003)J Food Prot. 66(4): 625 – 32. [2] Sartoratto A, Delarmelina C, Figueira G, Duarte M & Rehder V (2004) Braz J Microbiol 35: 275 – 80. [3] Weseler A, Geiss HK, Saller R & Reichling J (2005) Pharmazie 60: 497 – 502. [4] Işcan G, Kirimer N, Kürkcüoğlu M, Başer KH & Demirci F (2002)J Agric Food Chem 50(14): 3943 – 6.