ATIVIDADE ANTIBACTERIANA DO ÓLEO ESSENCIAL E EXTRATOS DE Lippia sidoides (CHAM.) VERBENACEAE E DO TIMOL FRENTE À Aeromonas hydrophila

Abstract

Among the aetiological agents involved in bacterial diseases in fish culture, Aeromonas hydrophila stands out, with the use of bioactive potential plants as an alternative for its control, replacing the use of antibiotics. Several biological properties have been attributed to the essential oil and extracts of Lippia sidoides ( Cham.) Verbenaceae. Thus, the objective of this study was to evaluate the antibacterial activity of the essential oil, aqueous and ethanolic extract of L. sidoides , as well as its major compound against A. hydrophila . For this, the ethanolic extract was obtained by contacting the crushed leaves with Ethyl alcohol and subsequent vacuum filtration and solvent removal. The aqueous extract by maceration with distilled water and vacuum filtration, and the essential oil by hydrodistillation. Subsequently, the antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) by the microdilution technique. The results of this study allowed to demonstrate the antibacterial activity of both types of L. sidoides extracts, as well as of its essential oil and the thymol against A. hydrophila . However, thymol activity was higher, followed by ethanolic extract, essential oil and aqueous extract. The MIC and MBC for thymol were: 78.13 µg mL -1 and 104.17 µg mL -1 for the ethanolic extract: 520 µg mL -1 and 625 µg mL -1 for the essential oil and for the aqueous extract were: 1,250 μg mL -1 for MIC and MBC. A strong antibacterial activity of thymol compound and ethanolic extract was evidenced in this study. Keywords: Minimum inhibitory concentration; minimum bactericidal concentration; alecrim-pimenta; terpen.