Mamica de porca (Zanthoxylum rhoifolium Lam., Rutaceae) is a native medicinal plant of occurrence in the Brazilian Cerrado Biome, the most diverse and rich savannas worldwide. It´s present in the states such as Tocantins, Roraima, Amapá, Pará, Amazonas, Acre, and Rondônia. The leaves are used to treatment of microbial infections and parasitic diseases, conferring alternative for health promotion and recovery. However, little is known about the action against Gram-positive and negative bacteria, expanding the knowledge about the potential of the antibacterial. To analyze the antimicrobial activity of leaf crude extract of Z. Rhoifolium L. front the standard strains Grampositive Staphylococcus aureus and Gram-negative Escherichia coli. The ethanolic extract was obtained in the Natural Products Laboratory (UAP) of the University UnirG, Gurupi-TO, Brazil, allotted to Muller Hinton Agar plates, in triplicate, inoculated with bacterial strains Standard American Type Culture Collection (ATCC): Gram-Positive S. aureus ATCC ® 29213 and Gram-Negative E. coli ATCC ® 25922, with the technique of wells for depositing 50 µL saline (negative control) and extract, with Gentamicin ® on disk 10μg for positive control. The plates were incubated in a greenhouse at 35 ± 1 º C for 24 hours, microbiology laboratory, measuring the diameter of the growth inhibition halos. The crude leaf extract of Z. Rhoifolium showed biological activity against Gram-positive bacteria S. aureus and Gram-negative E. coli, with moderately sensitive response and growth inhibition halos ranging from 14 to 16mm and 10 to 10.3mm, respectively. The antimicrobial potential of the crude leaf extract Z.Rhoifolium was checked against microorganisms of different cellular structures, expanding the possibilities of antimicrobial action, especially Gram-negative bacteria, being incipient studies in this perspective and not commonly identified for other medicinal species.
