Potential Antibacterial Activity of Essential Oil of Citrus hystrix and Chromolaena odorata Leaves

Abstract

Both Chromolaena odorata and Citrus hystrix leaves are known to have various biological activities. This study was designed to determine the antibacterial potential of essential oil of both plants. The essential oil was tested against the selected Gram-positive (Enterococcus faecalis and Staphylococcus aureus) bacteria and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria strains by using Kirby Bauer Disc Diffusion method. C. hystrix essential oil exhibited the highest inhibitory effect against E. faecalis where the highest inhibition zone was 16.33 ± 0.33 mm, followed by E. coli, with 15.4 ± 0.33 mm inhibition zone compared to the other bacteria. The result showed that both the gastrointestinal bacteria which were E. faecalis and E. coli were susceptible to the essential oil. The essential oil of C. odorata showed a potential antibacterial activity against E. faecalis and S. aureus with 17.3 ± 0.33 mm and 17.0 ± 0.58 mm of inhibition zones, respectively. In addition, a combination effect study was done to examine the possible synergistic antibacterial activity from bioactive compounds of both essential oil. The inhibitory effect of combined essential oil against E. coli showed the highest inhibition zone which was at 19.0 ± 0.58 mm, while the inhibition zones of bacteria growth for E. faecalis and S. aureus were at 17.7 ± 0.33 mm and 18.0 ± 0.58 mm, respectively. The results from this study showed that essential oil from both plants separately and in the combined state has the potential to be significant antibacterial agents in the pharmaceutical industry.