Antibacterial Activity and Phytochemical Analysis of Mentha piperita L. (Peppermint)—An Important Multipurpose Medicinal Plant

Mentha piperita L. (Peppermint) is a perennial glabrous and strongly scented herb belonging to family Lamiaceae. The plant is aromatic, stimulant and used for allaying nausea, headache and vomiting. Its oil is one of the most popular widely used essential oils in food products, cosmetics, pharmaceuticals, dental preparations, mouthwashes, soaps and alcoholic liquors. The antibacterial potential of six extracts from leaf, stem and root of Mentha piperita against pathogenic bacteria such as Bacillus subtilis, Streptococcus pneumonia, Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Klebsiella pneumonia were evaluated by agar well diffusion method. The organic (ethanol, methanol, ethyl acetate, chloroform, hexane and petroleum ether) extracts of the leaves were found to possess strong antibacterial activity against a range of pathogenic bacteria. The ethyl acetate leaf extract of Mentha piperita showed pronounced inhibition than chloroform, petroleum ether and hexane. The leaf extract activity being more on Bacillus subtilis, Staphylococcus aureus and Proteus vulgaris than Escherichia coli, Streptococcus pneumonia and Klebsiella pneumonia. In the present study, we also evaluated the phytochemical analysis for the presence of various secondary metabolites. The analysis revealed the presence of alkaloids, flavonoids, steroids, tannins, and phenols.