Synergistic Effects between Mentha Piperita, Mentha Longifolia and Ocimum Basilicum on Different Bacterial Strains

Abstract

The present study aimed to quantitatively evaluate antimicrobial activity of Mentha piperita, Mentha longifolia and Ocimum basilicum from Lamiaceae family, compare between them and to evaluate the type of interaction between them by microbroth dilution method and calculation of fractional inhibitory concentration. Dried leave of Mentha piperita, Mentha longifolia and Ocimum basilicum were extracted using same extraction method and solvent the highest ratio yielded by Mentha longifolia 9% and lowest ratio yielded by Ocimum basilicum 6%. Mentha piperita exhibit the lowest minimum inhibitory concentration value ranged between 1.5-<0.1 mg/ml, followed by Mentha longifolia and Ocimum basilicum ranged between 3-<0.1mg/ml with minimum bactericidal concentration ranged between 6-0.1875. On combination of leave extract Mentha piperita with Mentha longifolia exhibit the lowest minimum inhibitory concentration value ranged between 0.1875-<0.05 mg/ml, while combination of Mentha longifolia with Ocimum basilicum revealed minimum inhibitory concentration ranged between 0.75-<0.05. Among tested bacterial strain Streptococcus mitis showed high sensitivity against all tested leave extract alone and in combination form. The combinations of Mentha piperita, Mentha longifolia and Ocimum basilicum showed synergistic effects against most of bacteria. Mentha longifolia and Ocimum basilicum revealed antagonistic effect against Staphylococcus aureus. As a result three Lamiaceae species showed broad spectrum antimicrobial activity against isolated bacterial strain and their activity in combination form more pronounced than alone.