Chemical Composition and Biological Activities of Eugenia caryophyllata Thunb Essential Oil

Aims: In this study the antibacterial and antioxidant activities of the essential oil of Eugenia caryophyllata were investigated.

Study design: The study contains determination of the chemical composition of the essential oil of E. caryophyllata and the in vitro evaluation of the antibacterial and antioxidant activity of this oil.

Place and Duration of Study: The study was carried out at the laboratory of research on local animal products of Ibn-Khaldoun University, Tiaret, Algeria during the period from December 2020 to March 2021.

Methodology: The essential oil composition was characterized by gas chromatography/mass spectrophotometrical analyses. The antibacterial activity of this oil was tested against four pathogenic bacteria: Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 33862, Bacillus cereus ATCC 11778 by using disc diffusion method and agar incorporation method to determine the Minimum Inhibitory Concentration (MIC) of the tested oil. The antioxidant activity was evaluated by using DPPH radical scavenging, hydrogen peroxide scavenging assays and ferric reducing antioxidant power (FRAP) assay.

Results: Our results have shown a greater antibacterial effect of E. caryophyllata essential oil against all the bacterial tested strains with inhibition zone diameters varied from 17.5 to 20.5 mm and minimal inhibition concentration (MIC) ranged between 0.8 μl / ml and 4.4 μl / ml, B. cereus and S. aureus are the most sensitive species with a MIC value of 0.8 μl / ml, however P. aeruginosa is the most resistant species with a MIC value of 4.4 μl / ml. The result of the antioxidant effect showed that the essential oil of E. caryophyllata is a powerful antioxidant that expresses a higher antioxidant activity than the standard antioxidants: gallic acid, vitamin C and BHT.

Conclusion: The obtained results suggest that the essential oil of E. caryophyllata has a strong antibacterial and antioxidant effect and it may be an alternative natural source medicine to prevent and treat many diseases caused by pathogenic bacteria and oxidative stress.