Antibacterial and leishmanicidal activities of <i>Syzygium aromaticum</i> essential oil versus its major ingredient, eugenol

Abstract

Abstract The essential oil of Syzygium aromaticum (clove EO) and its major ingredients, eugenol, possess many biological activities such as antibacterial, antifungal, and antioxidant properties. Therefore, they have been widely used in traditional and contemporary medicine. In this study, the ingredients of clove EO were identified using GC‐MS analysis. The antibacterial and leishmanicidal activities of the total essential oil and eugenol were also investigated. Eugenol (65.41%), trans ‐caryophyllene (12.6%), eugenol acetate (9.85%), caryophyllene oxide (3.00%), and α‐humulene (1.73%) were identified as five major components of clove EO. Additionally, the obtained IC 50 s of clove EO, 177.66, 300.53, 362.94, and 248.08 μg/mL, against Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa , and Klebsiella pneumoniae , respectively, were lower than those of eugenol with IC 50 s of 320.80, 692.91, 591.82, and 445.87 μg/mL. However, this difference was not significant, except against E coli . Also, clove EO and eugenol showed proper leishmanicidal effects on promastigotes of Leishmania tropica (180.24 and 233.52 μg/mL) and Leishmania major (654.76 and 517.14 μg/mL). Furthermore, there was no significant statistical difference between the anti‐ Leishmania effect of EO and eugenol. Clove EO and eugenol showed proper antibacterial and leishmanicidal activities. However, the use of clove EO is preferable than eugenol because of the lower cost and straightforward preparation process.