Composition Chimique et Activité Anti-bactérienne et Antioxydante D’extrait Hydrométhanolique et Huile Essentielle de Juniperus Phoenicea

Abstract

This study focuses on the chemical composition and biological activity of hydrometh-anolic ether and the essential oil of Juniperus phoenicea L, a medicinal species of the family Cupressaceae widely distributed in Mediterranean regions, particularly in Algeria. The objective is to highlight the richness of this plant in secondary metabolites as well as its antioxidant and antibacterial properties. The essential oil was extracted by hydrodistillation using a Clevenger-type apparatus with a yield of 0.26%. The hydromethanolic extract (80%) was prepared by maceration and underwent decantation with cyclohexane to eliminate chlorophyll. The contents of polyphenols, flavonoids and tannins were determined by the method of Folin-Ciocalteu, AlCl3 and methanolic solution of vanillin. The antioxy-dante activity was evaluated by the DPPH test, while the antibacterial activity was studied by disc diffusion. The hydrometh-anolic extract showed the respective levels of polyphenols, flavonoids, and tannins: 453.99 μg EAG/mg extract, 41.80μEQ/mg extract and 28.04μg ECT/mg extract. The antioxidant profile of hydromethanolic extract with respect to DPPH is very important, with an IC50 of 264 μg/ml, but it is slightly lower than the BHT, BHA, and α-tocopherol standards, with respective values: 6.14, 12.99, and 13.02 μg/ml. The antimicrobial effect revealed that the essential oil showed strong activity against P. aeru-ginosa ATCC 27853, with inhibition zones ranging from 15 to 27 mm at highly diluted levels. However, E. coli was resistant; the inhibition zone at dilution levels is 6mm, whereas S. aureus is moderately sensitive; the inhibition zone at 1⁄2 dilution ranges from 10 to 12mm. The results show an interesting biological potential of the plant, suggesting its use in the phar-maceutical field