Antimicrobial Effect of Cinnamon Bark Extracts on Microbial Isolates

The use of plant extracts and phytochemicals, both with known antimicrobial properties, can be of great significance in therapeutic treatments. The aim of this study is to evaluate the antimicrobial activity of Cinnamomum zeylanicum (cinnamon) stick/bark extract on microbial isolates. The cinnamon barks were grounded and divided into two, one was macerated in ethanol and the other was macerated in water for 72hrs. The extract was tested for its antimicrobial effect on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus sp and Candida albicans using agar well diffusion methods. GC-MS was carried out to determine its bioactive compounds. For the ethanol extract, 200mg/ml had the highest zone of inhibition for S. aureus, P. aeruginosa. Bacillus sp and Candida albicans with 9.50mm, 14mm, 19.50mm, 18mm respectively and the highest for E. coli was 25 mg/ml at 8.80mm. The lowest zones of inhibition was found at 6.26mg/ml for all isolates. For the aqueous extract, 200mg/ml had the highest zone of inhibition and the lowest was found in 6.25mg/ml for all isolates. The minimum inhibitory concentration for all the organism for both the aqueous and the ethanol extracts is 25mg/ml. There is no bactericidal action for the aqueous extract but for the ethanol extract, 200mg/ml was the minimum bactericidal concentration for E. coli, P. aeruginosa and S. aureus while 100mg/ml was the minimum bactericidal concentration for Bacillus sp., and Candida sp. In the aqueous extract, 2H-1-Benzopyran-2-one-4-diethylphosphonate was found to be the most abundant compound with a percentage area of 28.09%. In the ethanol extract, Octamethylcyclotetrasiloxane and, Dodecamethylpentasiloxane were found to be the most abundant compounds with percentage areas of 10.98% and 6.64% respectively. From the results presented, it showed that cinnamon barks have antimicrobial properties and also certain compounds that have been reported to contribute to its properties.