Abstract

Essential oils extracted from plants are currently being used in chemical syntheses or as new materials, with various medical, pharmaceutical, technological and business applications. In this context, this study was carried out to evaluate the antimicrobial activity of the essential oil obtained from the verbena - Stachytarpheta cayennensis, (Rich.) Vahl. - (Verbenaceae) - collected in the Southwest region of Paraná - Brazil, on the pathogenic bacteria Escherichia coli ATCC-25922, Staphylococcus aureus ATCC-25923 and Pseudomonas aeruginosa ATCC-9027. The oil was extracted through hydro distillation in a Clevenger apparatus. The Agar diffusion method was used to evaluate the antimicrobial activity. Based on the obtained results, the bacterium E. coli ATCC-25922 was observed to be susceptible to the action of the oil, presenting a minimum inhibitory concentration (MIC) of 1.56%. The S. aureus ATCC-25923 strain, on the other hand, was also susceptible to the action of oil, but more resistant, since its MIC was a concentration of 12.5%. The bacterium P. aeruginosa ATCC-9027 proved to be resistant to the components of the evaluated oil at concentrations from 25 to 0.78%, but it was susceptible to concentrations ranging from 100 to 50%, with the MIC for this strain being 50% of oil.

Key words: Medicinal plants, antimicrobials, metabolites, drugs.