Antimicrobial activity of rosemary, peppertree, guinea henweed and hepazote against Staphylococcus aureus and Escherichia coli.

Abstract

The efforts to increase the empirical knowledge of medicinal plants aim to improve treatments of diseases or to promote health, and may become an alternative in the discovery of new, effective medical drugs. This study investigates the antimicrobial activity of the juices of Rosmarinus officinalis Linnaeus (Rosemary), Schinus terebinthifolius Raddi (Peppertree), Petiveria alliacea L. (Guinea Henweed) and Chenopoduim ambrosioides L. (Hepazote) against Staphylococcus aureus and Escherichia coli. Antimicrobial activity of juices was assessed at different concentrations, required to inhibit the growth of the microorganisms. The most effective plant against the microorganisms was established. Antibacterial action was determined by disk diffusion on Müeller-Hinton Agar using 1.0 mL of different juice concentrations (1.0, 0.5, 0.25, and 0.125). Assays were carried out in triplicate. Dishes were incubated in a stove at 36ºC for 24 h. Then, inhibition halos were measured. Only Guinea Henweed and Hepazote juices exhibited antimicrobial activity. S. aureus was the most sensitive to Peppertree juice, in all methods. The results show that medicinal plants exhibit high antibacterial potential and therefore are an excellent source of new antimicrobial agents. Further studies should be carried out using other disk diffusion methods and concentrations, and test other plants against other bacteria.