Minimal Inhibitory Concentration and Minimal Bactericidal Concentration of Peppermint (Mentha piperita) extracts against standard microorganisms

Abstract

Different plant extracts are considerably safe from infectious agents and may be used for medical purposes. The present research was conducted against the six standard microorganisms to quantify the antimicrobial activities of peppermint (Mentha piperita) extracts. The traditional approaches of minimum bactericidal concentration (MBC) and minimal inhibitory concentration (MIC) were used to approximate the antibacterial activities of ethanol, methanol, and chloroform peppermint extracts. The inhibitory function of the ethanol extract was comparable to that of chloroform (10 to 80mg/ml) and methanol (10 to 80mg/ml) against all gram-negative microorganisms. The minimum value of MIC was recorded for Streptococcus pyogenes (5mg/ml for extract of ethanol), followed by E. coli (10mg/ml for extract of ethanol) and then by Enterococcus faecalis (15mg/ml for extract of ethanol). With respect to the standard microorganisms, the MBC values were higher for both extracts than the corresponding MIC values. This work demonstrated the possible efficacy of antibacterial action on M. Piperita extracts from normal microorganisms (A. Baumenii, Escherichia coli, Streptococcus pyogenes, Enterococcus faecalis, Pseudomonas aeruginosa and Klebsiella pneumoniae), particularly ethanol extract. In summary, the peppermint ethanol extract had important growth-inhibiting effects on observed standard micro-organisms, followed by chloroform and methanol extracts. Further to in vitro and in vivo studies on a wide variety of natural microorganisms and therapeutic isolates are required to investigate and standardize the inhibitory activity of peppermint extracts against the most dangerous human pathogenic agents.