In Vitro Study of Antibacterial Activity of Aromatic and Medicinal Plants Essential Oils with Special Reference to Cinnamon Oil

Antibacterial activity of 19 essential oils was screened against four test bacteria namely Pseudomonas aeruginosa NCIM 5029, Staphylococcus aureus NCIM 5021, Salmonella typhimurium NCIM 2501 and Bacillus subtilis NCIM 2063. Varying degree of antibacterial activity was recorded with the highest being depicted by Cinnamomum zeylanicum followed by Cymbopogon ciatrus and Carum copticum, against all bacteria. MIC of cinnamon oil was determined through agar well diffusion assay. Staphylococcus aureus and B. subtilis were most susceptible, exhibiting MIC values 0.2 and 0.4 μl oil/well respectively. Antibacterial assay of the column chromatography fractions clearly indicated that the primary compound cinnamaldehyde is responsible for major antibacterial activity. Bioautography of cinnamon oil was done to detect qualitative antibacterial activity.