Évaluation des Activité antioxydante, anti-inflammatoire et antibactérienne des extraits de deux plantes médicinales

Abstract

Juniperus oxycedrus and Juniperus phoenicea are medicinal plants used for therapeutic purposes. Samples were collected in the Ouled Tebban region, Sétif, on 7 January 2025. Our study aimed to investigate the phenolic compounds, antioxidant, anti-inflammatory and antibacterial activity of the extracts. The extracts were prepared by decoction (AQ) and maceration (EOH). The yields of the aqueous and ethanolic extracts were 10% and 25% for J. oxycedrus, and 14.7% and 11.4% for J. phoenicea, respectively. The total phenolic compound content of the J. oxycedrus extract was (25.311 ± 2.203) and (27.50 ± 1.12) of the extract. And (2.94 ± 0.161) and (5.466 ± 1.283). As for the J. phoenicea plant, the total phenolic compounds were (25.50 ± 1.390) and (28.44 ± 0.494) and the flavonoids (3.87 ± 0.894) and (7.10 ± 0.519) for the ethanol and aqueous extracts, respectively. The results obtained for antioxidant activity also showed that the extracts had antioxidant capacity in the bêta-carotene bleaching test. As for the DPPH test, they were less active, as the IC50 value for the J. oxycedrus extract was (42.82 ± 3.89 μg/ml) and (27.64 ± 2.11 μg/ml), and the IC50 for the J. phoenicea extract was (32.90 ± 1.51) and (30.85 ± 1.83) for the AQ and EOH extracts, respectively. As for anti-inflammatory activity, the study showed that aspirin remains the most effective (89.9% at 10 μg/ml). As for J. oxycedrus, (EOH) is promising (58.9% at 5 μg/ml). Conversely, J. phoenicea showed better activity with the aqueous extract (57.77% at 1.25 μg/ml). In terms of antibacterial activity, the ethanolic extract of J. phoenicea eliminated S. aureus, E. coli and P. aeruginosa, while C. albicans and B. subtilis were resistant to it. In contrast, the aqueous extract of the same plant inhibited S. aureus, C. albicans and B. subtilis. As for J. oxycedrus, its ethanol extract killed only S. aureus and inhibited E. coli, P. aeruginosa and C