Evaluation of antimycobacterium activity of the essential oils of cumin (<i>Cuminum cyminum</i>), clove (Eugenia caryophyllata), cinnamon (<i>Cinnamomum verum</i>), laurel (<i>Laurus nobilis</i>) and anis (<i>Pimpinella anisum</i>) against <i>Mycobacterium tuberculosis</i>

In this study Essential oils were used with cumin, cloves, cinnamon, laurel and anis to determine Minimum Inhibitory Concentration (MIC) against Mycobacterium tuberculosis strains. The MICs were determined on M. tuberculosis H37Rv sensitive to all five firstline antituberculosis drugs (streptomycin, isoniazid, rifampicin, ethambutol and pirazinamide), two H37-Rv (CH-8 and CH-15) isoniazid-resistant, two H37Rv (CH-07 and CH-09) rifampicin-resistant, two H37Rv (CH-03 and CH-06) streptomycin-resistant, and two H37Rv (CH-09 and CH-10) ethambutol-resistant using the microplate alamar blue assay. The results obtained showed that the cumin and cinnamon essential oils showed a MIC of 12.5 μg/ml against reference strain H37Rv. The five essential oils used in this study were effective against the isoniazid-resistant variant of H37RV with MIC values in the range 12.5-100 μg/ml, the most potent being the cumin and cin-namon (MIC = 12.5). Similar results were obtained against rifampicin-resistant variant of H37RV with MIC values in the range 12.5-100 μg/ml;the most active ones?in this case were the essential oils of cumin and cloves. The essential oils of anis and laurel were active with MIC value to 100 μg/ml. Clove, cumin, and cinnamon essential oils were active against all strains utilized in this study, with MIC values in the range 6.25 μg/ml to 25 μg/ml.