Chemical composition, in-vitro antibacterial and antioxidant activities of Syzygium aromaticum essential oil

The aims of this study were to investigate the chemical composition, in-vitro antioxidant and antibacterial activities of Syzygium aromaticum essential oil. The essential oil was obtained by hydrodistillation. The GC–MS/GC–FID was used for determination of essential oil composition. The antioxidant activity was determined by DPPH radical scavenging assay and reducing power. The antimicrobial activity was evaluated by the broth microdilution method against six enteropathogens bacteria isolated from diarrhea of young calves. The results of the study revealed an average yield of the essential oil of 11.6% ± 0.97 (w/w). About 65 components were identified and quantified. Eugenol was the major compound of the studied essential oil (78.72%) followed by β-caryophyllene (8.82%) and eugenyl acetate (8.74%). The antioxidant activity by DPPH assay showed IC50 value of 4.82 ± 0.06 × 10 −2 µg/mL, while the reducing power assay have resulted an EC50 value of 3.47 ± 0.2 × 10 −2 µg/mL. The results showed that the essential oil exhibited an MIC at 1.36 mg/mL to 2.72 mg/ml and MBC at 5.45 mg/mL to 10.9 mg/mL against all tested bacteria. The present investigation revealed that Syzygium aromaticum essential oil exhibited a good in-vitro antioxidant and moderate in-vitro antibacterial activities.