Antibacterial properties of the leaf extract of Mentha arvensis L.

The antibacterial activity of methanolic and aqueous leaf extracts of Mentha arvensis L. (Family: Lamiaceae) has been tested against five strains of human pathogenic bacteria namely Escherichia coli, Pseudomonas aeruginosa, Shigella flexineri, Klebsiella pneumoniae and Staphylococcus aureus. Both methanolic and aqueous extracts did not effect the growth of E.coli. Staphylococcus aureus and Shigella flexineri were not affected by the aqueous extracts, but influenced by methanolic extracts. Methanolic and aqueous extracts had shown their effect in concentrations ranging from1.25% to 10% and 2.5% to 10%, respectively on selected bacteria. The antibacterial activity was more significant against Shigella flexineri, i.e., 14 mm zone by methanol extract and Klebsiella pneumonia, i.e., 10 mm zone by aqueous extract.