Ilex paraguariensis A. St. - Hil. ("erva mate") is a tree of the Aquifoliaceae family, native to the south region of South America and of great cultural and economic importance for the three states of the south region of Brazil. The present study aimed to determine the antimicrobial potential of "erva mate" extract obtained by supercritical fluid against some microorganism strains. The leaves of Ilex paraguariensis were collected in the north region of Rio Grande do Sul State. The crude extract of dehydrated plant was obtained by supercritical fluid extraction, using carbon dioxide (CO2) as solvent. The extract mother solution (100 mg mL-1) was diluted (50; 25; 12, 5; 6.25 mg mL-1) for antimicrobial activity evaluation, by means of disk diffusion method on Müeller-Hinton agar, against strains of Acinetobacter baumannii (ATCC 19606), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923) and Enterococcus faecalis (ATCC 29212). The analyses were done in triplicate, using as negative control sterile disk without impregnation and as positive control, commercial antibiotic disks according to the bacterial species. After 16-24h incubation at 35ºC, the diameters of inhibition zones were measured. Antimicrobial activity was observed against S. aureus (inhibition zones between 7 and 18 mm) and P. aeruginosa (inhibition zones between 6 and 11 mm), both at the concentrations of 100 mg mL-1 to 25 mg mL-1. The extract of Ilex paraguariensis obtained by supercritical fluid presented antimicrobial activity against S. aureus and P. aeruginosa.
Ilex paraguariensis; antimicrobial activity; supercritical crude extract
