Antibacterial effect of nine hydroalcoholic extracts of ethnomedicinal plants from Huayucachi-Peru on gram-positive bacteria

Abstract

Introduction: Ethnomedicinal plants from the district of Huayucachi-Peru exhibit chemical components with the ability to inhibit gram-positive bacteria. Objectives: To evaluate the antibacterial effect of 9 hydroalcoholic extracts of ethnomedicinal plants from Huayucachi-Peru on Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes. Methods: Experimental, in vitro and comparative study. Initial phytochemical screening of the extracts was performed. Ninety-nine Müller-Hinton agar plates (Merck®) were used, divided into 11 groups (n= 9): Group I (70 % ethanol), group II (ciprofloxacin 10 ug), group III to XI extracts of lemon verbena, borage, rabbit ear, red nettle, pimpernel, eucalyptus, lemon balm, tumbo serrano and asmachilca at 25 %, respectively. The Kirby-Bauer disk diffusion method was used; the strains used were S. aureus ATCC 25923, S. pneumoniae ATCC 49619 and S. pyogenes ATCC 19615 and the inhibition halos were measured at 24 hours. Results: Phenolic and flavonoid compounds were detected in the phytochemical screening. Inhibition ranges of 12.725 ±0.0411 to 17.617 ±0.0405 mm were obtained for S. aureus; 13.017 ±0.0366 to 18.133 ±0.0432 for S. pneumoniae and 12.992 ±0.0336 to 17.550 ±0.0417 for S. pyogenes. Rabbit ear, red nettle and tumbo serrano extracts showed the highest antibacterial activity, against S. aureus, S. pneumoniae and S. pyogenes, respectively. Conclusions: The 9 hydroalcoholic extracts of ethnomedicinal plants demonstrate to have an effect on the bacteria under study and constitute a promising source of antibacterial chemical compounds.

Keywords

• bacterias grampositivas
• compuestos fenólicos
• flavonoides
• plantas medicinales.