Chemical Composition and Antibacterial Activity of Berries Essential Oil of Algerian Juniperus thurifera (Var. aurasiaca)

Abstract

Background: Over the past decade, most antibiotic research programs have focused on finding new compounds with antimicrobial activity. This study aims to investigate the chemical composition and antibacterial activity of the essential oil (EO) extracted from ripe berries of Algerian Juniperus thurifera var. aurasiaca. Methods: The chemical composition of J. thurifera EO extracted by hydrodistillation was analyzed by using the GC-MS technique. Antibacterial activity of EO alone and in combination with three conventional antibiotics was assessed by using disc diffusion method against four bacterial strains. Results: Thirty-five components were identified, representing ~87 % of the oil. The main components were m-mentha-6,8-diene (15.43 %), β-pinene (10.59 %), elemol (8.31 %) and terpinene-4-ol (7.44 %). The essential oil showed strong antibacterial activity against S. aureus and E. coli, but no activity against P. aeruginosa and B. subtilis. Synergistic effects were observed because of the combined application of EO with gentamicin against all strains tested, and with amoxicillin against B. subtilis. Furthermore, the combination of EO/cefazolin demonstrated an additive effect against B. subtilis. In contrast, the combination of EO with amoxicillin and céfazoline revealed antagonistic effects against S. aureus, E. coli, and P. aeruginosa. Conclusion: This is the first report on the chemical composition and antibacterial activity of Algerian juniper berries’ essential oil. The results indicate that the studied EO may be a promising source of antibacterial compounds that could be useful for pharmaceutical applications especially in combination with conventional antibiotics.

Sustainable Use of Extracts of Some Plants Growing in Ethiopia for the Formulation of Herbal Shampoo and Its Antimicrobial Evaluation

“…The mass spectra of each compound were scanned across the m/z range of 50 to 650. Identification of the compounds was obtained by comparing their mass spectra and retention times with those of standards (NIST14.lib) and those found in literature [34].…”

Synergistic effects of Ruta montana (Clus.) L. essential oil and antibiotics against some pathogenic bacteria

“…If the value of the inhibition zone of the EO/ AB combination is significantly higher (P <0.05) than the sum of the individual values, this is considered to be a synergistic effect, but if they are equal (P ≥0.05), then this is considered an additive effect. The antagonistic effect occurs when the values of the inhibition zones of both treatments separately EO/AB are significantly greater than the value of their combination (Boudjedjou et al, 2018(Boudjedjou et al, , 2019.…”

“…The occurrence of synergism is thought to be the key to the bioactivity of EOs (Boonyanugomol et al, 2017;Chouhan et al, 2017). Therefore, the association between EOs and ABs has emerged as a novel approach in controlling multidrug-resistant (MDR) strains and modulating the activity of ABs (Boonyanugomol et al 2017;Chouhan et al, 2017;Boudjedjou et al, 2018Boudjedjou et al, , 2019.…”

Valorization of the Sabinas Forest Waste (Juniperus phoenicea and Juniperus thurifera) as Source of Biopesticides

“…9 These two species have medicinal applications and have been reported to alleviate diseases such as diarrhea, arthritis, diabetes, 13 and to cure ulcers. 14,15 In addition, essential oils (EOs) of J. phoenicea and J. thurifera have shown antimicrobial, antifungal, and cytotoxic activity, 9,[15][16][17] and EOs from leaves of J. thurifera have been reported to be used for pest control. Thus, these oils were reported to be active as insecticide against Acanthoscelides obtectus, Tribolium castaneum, and Sitophilus oryzae.…”

“…With regard to the composition of the arcestides, the EO of J. phoenicea arcestides is rich in α-pinene with a proportion ranging between 33% and 88%, 15,20,24 whereas the EO of J. thurifera arcestides presents a significant disparity, with the European variety being rich in limonene, 25 and the African variety containing mostly mentha-6,8-diene, β-pinene, elemol, and 4-terpineol. 16…”