Chemical composition and antibacterial activity of essential oils from six Moroccan plants

摘要

The essential oils (EOs) of six plants (Artemisa herba alba,?Rosmarinus?officinalis,Ocimum basilicum,?Lavandula officinalis,?Mentha viridis?and?Mentha?piperita) widely distributed in Morocco were isolated and their chemical composition was investigated by gas chromatography-mass spectrometry (GC/MS). These EOs were tested?in vitro?against four pathogenic bacterial strains (Enterococcus faecalis,?Escherichia coli,?Klebsiella pneumoniae?and?Streptococcus D) and we determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of each EO. The oils of various plants showed high activity against all tested bacteria (MIC≤10 μL/ml), of which?K. pneumoniae?was the most sensitive strain (MIC≤5 μL/ml). In addition, the oil from?M. viridisL. which contained high pulegone concentration (45%) exhibited a very interesting antibacterial activity against all the bacterial strains (MIC 2.5 μL/ml) and (MBC 2.5 μL/ml). The UV-visible study on the release of material absorbing at 260 nm showed significant leakage of cytoplasmic contents, indicating damage to the bacterial cell membrane integrity. Thus, these results indicate that the EOs represent a potential source of natural antibacterial substances that may be used against pathogenic systems.