Composition analysis and antibacterial activity evaluation of different crude extracts of Mentha piperita (Lamiaceae)

Abstract

Globally, the main target of scientists is to examine new medicinally beneficial plants for the preparation of herbal drugs as well as to explore possible uses in the food industry. In this regard, the target of our current study is to evaluate the antibacterial activity and biochemical analyses of the leaf extracts of Omani Mentha piperita L (M. piperita). The selected plant leaves coarse powder samples were extracted by using the Soxhlet extraction process with methanol at 65oC for a period of 72 hours. The evaporation of methanol was done by a rotary evaporator under reduced pressure and temperature. The hydro alcoholic extract was fractionated with the various polarities of solvents with an increasing pattern. The biochemical evaluation and pharmacological activity of the prepared local plant extracts were completed by using established methods. The different polarities of leaves extracts showed positive biochemical tests of alkaloids, flavonoids, glycosides, saponins, steroids, tannins and triterpenoids. The microbial activity of the fractioned plant extracts was tested with improved agar gel method. The different polarity extracts at different concentrations did not display any activity against the tested Gram (+) Staphylococcus aureus (S. aureus) and Gram (-) Escherichia coli (E. coli) and Pseudomonus aeruginosa (P. aeruginosa) bacterial strains. Based on the biochemical and pharmacological evaluation results, the selected whole plant and its potential extracts might be used traditionally as natural antibiotics to treat infectious diseases.