Essential Oils of Rosmarinus officinalis and Eucalyptus globulus Cultivated in the Mountainous Region of the State of Rio de Janeiro (Brazil): Chemical Profile and Antileishmanial Activity

The present study aimed to characterize the chemical profile of essential oils of Rosmarinus officinalis (EORo) and Eucalyptus globulus (EOEg) cultivated in the mountainous region of the state of Rio de Janeiro, Brazil, and to verify the leishmanicidal potential, as well as to determine the cytotoxicity in vitro in mammalian cells. EORo had α-Pinene (37.99%), Cineol (21.48%), D-Verbenone (5.78%) and Limonene (3.28%) as major constituents. The EOEg had as major components Cineol (75.52%), Limonene (8.82%) and o-Cymeno (7.81%). The EOEg had a lower IC₅₀ value of 14.03 ± 2.08 μg/mL, while EORo had an IC₅₀ value of 31.12 ± 4.6 μg/mL, both during the 24-hr exposure period. In the 48-hr period, the IC₅₀ value was almost twice as high with rosemary oil, while in eucalyptus oil there was no significant difference when exposed in this period. The selectivity of EOs was demonstrated in murine cells, showing almost 30 times less toxic to the cell than to the parasite. It can be concluded that this is a pioneering study on the potential of these essential oils against the leishmania parasite. Furthermore, the low toxicity effect on the host cell encourages future studies and in vivo applications.