Assessment of chemical compositions and antibacterial activity of the essential oil of Mentha piperita in response to salicylic acid

Mentha piperita, as a species of the mint family, is used in various medical, cosmetic, industrial and culinary products. The effect of different concentrations of salicylic acid (SA) (0. 0.5, 1 mM) on phytochemical activity and antimicrobial potential of Mentha piperita essential oil against six human pathogenic bacteria (Streptococcus agalactiae, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Listeria monocytogenes) were investigated. According to the results to prevent the growth of L. monocytogenes and S. agalactiae, Gram-positive bacteria, peppermint, essential oil treatment with 1 mM salicylic acid is suggested. But to prevent the growth of Gram-negative bacteria P. aeruginosa and E. coli, peppermint essential oil of control plants is proposed. These results showed that salicylic acid elicitor changed the type and amount of peppermint essential oil compounds. Probably, salicylic acid elicitor improved antimicrobial properties of peppermint essential oil with a change in essential oil components. The inhibitory activity of essential oil depends on the type of microorganism, the concentration of essential oil and the concentration and time of salicylic acid treatment.