Antibacterial Activity of Geraniol in Combination with Standard Antibiotics against Staphylococcus aureus, Escherichia coli and Helicobacter pylori

• Published in: Natural product communications 2018-07, Vol.13 (7)
• Main Authors: Bhattamisra, Subrat Kumar, Kuean, Chew Hui, Chieh, Lee Boon, Yan, Vivian Lee Yean, Lee, Chin Koh, Hooi, Lee Peng, Shyan, Lai Pei, Liew, Yun Khoon, Candasamy, Mayuren, Sahu, Priyadarshi Soumyaranjan
• Format: Article
• Language: English
• ISSN: 1934-578X; 1555-9475
• DOI: 10.1177/1934578X1801300701

The antibacterial activity of geraniol and its effect in combination with ampicillin, amoxicillin and clarithromycin against Staphylococcus aureus, Escherichia coli and Helicobacter pylori was tested. The minimum inhibitory concentrations (MICs) and combinatory effects of geraniol against the bacteria were assessed by using the modified broth microdilution and checkerboard assay, respectively. The combinatory effect is expressed as fractional inhibitory concentration index (FICI). The MIC of geraniol against S. aureus, E. coli and H. pylori was found to be 11200, 5600, and 7325 μg/mL, respectively. A significant synergistic effect was observed with geraniol and ampicillin against S. aureus with FICI in the range 0.19 to 0.32. Geraniol and ampicillin exhibited a partial synergistic effect against E. coli. A similar effect was observed with geraniol and clarithromycin against S. aureus. A partial synergistic effect was observed with clarithromycin and geraniol against H. pylori with the FICI value in the range 0.86 to 0.89. An additive effect was observed with geraniol and amoxicillin combination against H. pylori. However, the amoxicillin and clarithromycin dose was reduced by thirty-two fold when combined with geraniol against H. pylori. The anti-H. pylori effect of geraniol with clarithromycin and amoxicillin could be of potential interest in the treatment of H. pylori infection and associated ulcers in humans. Further, geraniol, in combination with other antibiotics, has substantial therapeutic potential against S. aureus and E.coli infection.