Caractérisation phytochimique et évaluation des activités biologiques des extraits d’Artemisia herba-alba.

Abstract

Artemisia herba-alba Asso (Chih) is a medicinal plant widely used in Algerian traditional medicine due to its numerous therapeutic properties. The present study aimed to characterize the phytochemical composition and evaluate the antioxidant and antibacterial activities of the methanolic extracts of this species. Leaves of Artemisia herba-alba, collected from the steppe region of Mascara, were subjected to two extraction methods: maceration and Soxhlet extraction. The extraction yields obtained were 8.96% for maceration and 10.37% for Soxhlet extraction. Phytochemical screening revealed the presence of several groups of secondary metabolites, including polyphenols, flavonoids, tannins, terpenoids, and alkaloids, while saponins and steroids were absent. Quantitative analysis showed that the maceration extract was the richest in total polyphenols (23.49 ± 1.78 mg GAE/g DW), whereas the Soxhlet extract exhibited the highest flavonoid content (1.48 ± 0.05 mg QE/g DW). The evaluation of antioxidant activity using the DPPH assay demonstrated a concentration-dependent activity for both extracts. The Soxhlet extract showed the strongest antioxidant activity with an IC₅₀ value of 200.79 ± 3.10 μg/mL, compared with 216.66 ± 2.93 μg/mL for the maceration extract. The antibacterial activity, assessed using the disc diffusion method, revealed variable inhibition against the tested bacterial strains. Escherichia coli was the most sensitive strain to the methanolic extracts, followed by Pseudomonas aeruginosa and Staphylococcus aureus. The obtained results confirm the phytochemical richness of Artemisia herba-alba and highlight its potential as a natural source of bioactive compounds with antioxidant and antibacterial properties that could be exploited in pharmaceutical and cosmetic applications.