Antimicrobial and Antioxidant Activities of Four Essential Oils

Various opportunistic microorganisms, such as bacteria and fungi, are responsible for multiple infectious diseases, which represent a threat to global health. Essential oils (EOs) have shown antimicrobial and antioxidant properties, making them an excellent alternative to control multi-resistant bacteria. In this work, for the first time, the antimicrobial and antioxidant activities of four EOs were evaluated, namely Trixis angustifolia DC (EOTA), Dalea bicolor Humb & Bonpl. Ex Willd (EODB), Tagetes parryi A.Gray (EOTP) and Eupatorium glabratum Kunth (EOEG). They were obtained by hydrodistillation, and their chemical composition was determined by GC-MS (Gas chromatography-mass spectroscopy) using HP5-MS column. Their antimicrobial and antioxidant activities were determined by the microdilution method and the DPPH and ABTS techniques, respectively. The main compounds of the EOs were piperitone (36.67 %) for EOTA, β-pinene (27.25) for EODB, verbenone (31.13 %) for EOTP and α-cadinol (7.78 %) and bornyl acetate (6.45 %) for EOEG. The EOs EOTA, EODB, EOTP and EOEG inhibited the development of Candida at a concentration of 62.5–500 µg/mL, whereas the antibacterial activities of these oils were observed at concentrations from 125–500 µg/mL. The antioxidant activity of EOTA and EODB were IC50 = 0.641, 1.195 mg/mL, whereas those of EOTP and EOEG was lower. These results show that four EOs have antimicrobial activity. Resumen. Diversos microorganismos oportunistas, como bacterias y hongos, son responsables de múltiples enfermedades infecciosas, que representan una amenaza para la salud mundial. Los aceites esenciales (EOs) han demostrado propiedades antimicrobianas y antioxidantes, lo que los convierte en una excelente alternativa para el control de bacterias multirresistentes. En este trabajo, por primera vez, se evaluaron las actividades antimicrobianas y antioxidantes de cuatro EOs: Trixis angustifolia DC (EOTA), Dalea bicolor Humb & Bonpl. Ex Willd (EODB), Tagetes parryi A.Gray (EOTP) y Eupatorium glabratum Kunth (EOEG). Los aceites se obtuvieron por hidrodestilación y se determinó su composición química por GC-MS (cromatografía de gases-espectrometría de masas) utilizando una columna HP5-MS. Sus actividades antimicrobiana y antioxidante se determinaron por el método de microdilución y las técnicas DPPH y ABTS, respectivamente. Los principales compuestos de los aceites esenciales fueron piperitona (36,67 %) para EOTA, β-pineno (27,25 %) para EODB, verbenona (