Inhibitory potential of nine mentha species against pathogenic bacterial strains

Plants produce secondary metabolites,which are used in their growth and defense against pathogenic agents. these plant based metabolites can be used as natural antibiotics against pathogenic bacteria. synthetic antibiotics caused different side effects and become resistant to bacteria. therefore the main objective of the present study was to investigate the inhibitory potential of nine mentha species extracts against pathogenic bacteria. the methanolic leaves extracts of nine mentha species (mentha arvensis,mentha longifolia,mentha officinalis,mentha piperita,mentha citrata,mentha pulegium,mentha royleana,mentha spicata and mentha suareolens) were compared for antimicrobial activities. these mentha species showed strong antibacterial activity against four microorganisms tested. mentha arvensis showed 25 mm and 30 mm zones of inhibition against staphylococcus aureus,vibrio cholera and enterobacter aerogens. moreover,mentha longifolia showed 24 mm zone of inhibition against staphylococcus aureus. mentha officinalis showed 30 mm zone of inhibition against staphylococcus aureus. 25 mm inhibitory zone was recorded against staphylococcus aureus by mentha piperita. mentha royleana showed 25 mm zone of inhibition against vibrio cholera,while mentha spicata showed 21 mm,22 mm and 23 mm zones of inhibition against staphylococcus aureus,vibrio cholera and enterobacter aerogens. moreover most of the mentha species showed zone of inhibition in the range of 10-20 mm. © 2015,pakistan botanical society. all rights reserved.