Antiamoeba and Antitrypanosoma Activity of the Mexican Plectranthus amboinicus Essential Oil

Plectranthus amboinicus (Loureiro) Sprengel is a plant whose essential oil has different properties; its composition varies according to the geographical area of cultivation. In this work, we aimed to identify by GC-MS the metabolites that are present in the essential oil of P. amboinicus grown in Mexico City and evaluate its effects against Entamoeba histolytica trophozoites and Trypanosoma cruzi trypomastigotes and epimastigotes. Additionally, its cytotoxicity on Vero cells was determined. Results showed that the essential oil of P. amboinicus cultivated in Mexico City is made up 46 compounds, belonging mainly to four classes of terpenoids, camphor being the major compound with an abundance of 30.64%, followed by alloaromadendrene oxide (14.43%), caryophyllene oxide (6.61%), aromadendrene oxide (6.47%) and carvacrol (5.8%). The essential oil possesses antiamoebic activity (IC50 of 121.7 μg/mL) and antitrypanosomic activity against trypomastigotes (LC50 = 61.66 μg/mL) and epimastigotes (IC50 of 210.8 μg/mL), being more effective against T. cruzi trypomastigotes, since it has an LC50 close to that of the reference drug benznidazole which is 25.72 µg/mL (98.83 µM). Future research will allow us to characterize the molecular effects that the essential oil of P. amboinicus cultivated in Mexico City has on the protozoan parasites E. histolytica and T. cruzi, and to compare the activity of the essential oil with respect to that of the individual metabolites, in mixtures and in combination with reference drugs.