Chemical Profile, in vitro Antibacterial and Antioxidant Activities ofJuniperus phoeniceaL. and Cotula cinerea (Del.) Essential Oils from Southwestern Algeria

Abstract

This work aims to study the chemical composition, antimicrobial and antioxidant activities ofJuniperus phoeniceaL. andCotula cinerea(Del.) essential oils from southwestern Algeria. The hydrodistilled oils obtained were characterized by gas chromatography–mass spectrometry (GC– MS). A total of 45 and 25 compounds were identified representing 100% ofJuniperus phoeniceaL. andCotula cinerea(Del.) respectively. The dominant component was α-pinene (46.437%) forJuniperus phoeniceaL. and α-thujone (32.35%) forCotula cinerea(Del.). The in vitro antibacterial activity of the essential oils was evaluated against nine foodborne pathogenic bacteria and one yeast, Candida albicans, using the disk diffusion method; the minimum inhibitory concentration (MIC) values were examined (micro dilution). The results suggest that the essential oil ofJuniperus phoeniceahas a significant to moderate antibacterial activity on all strains of bacteria. The most sensitive strains were Bacillus cereus, Bacillus subtilis,Micrococcus luteus,Pseudomonas aeruginosa, andCandida albicanswith (MIC = 0.04 to 0.63 mg/ml).Cotula cinereaoil showed moderate to low sensitivity to the test strains. Its best activity was against Bacillus subtilis (MIC = 0.303 mg/ml). The DPPH test conducted to evaluate the antioxidant activity of both oils showed a good to moderate capacity forJuniperus phoeniceaL. (concentration of an inhibitor when the response is reduced by half, IC50 = 0.76 mg/ml) andCotula cinerea(Del.) [IC50 = 28. mg/ml] oils respectively. The promising bioactivities of these plants suggest that they may be a new source of preservative molecules.