Phytochemical screening and evaluation of antioxidant and antibacterial activities of leaf extracts of the Moroccan medicinal plant Warionia saharae

Warionia saharae is a medicinal plant with diverse applications in traditional medicine. In this study, leaf extracts obtained using four solvents (chloroform, methanol, 50% methanol, and water) were evaluated for their total phenolic content (TPC), flavonoid content (TFC), and tannin content (TTC). Antioxidant activity was assessed through five tests (DPPH, ABTS, FRAP, TAC, and H2O2 scavenging), and antibacterial activity was tested against four bacterial strains (Escherichia coli CIP 54127, Pseudomonas aeruginosa, Klebsiella pneumoniae CIP 8290T, and Staphylococcus aureus ATCC 25923). The results revealed that the methanolic extract exhibited the highest level of TPC (385.315 ± 39.15 mg GAE/g) and TFC (26.59 ± 0.90 mg QE/ml) and demonstrated the highest antioxidant effects in DPPH, ABTS, and FRAP tests. It also showed potent antibacterial activity, particularly against S. aureus and E. coli with inhibition zone diameters of 23.5±2.12 and 19 mm, respectively, comparable to those obtained with the standard antibiotic Gentamicin. A strong positive correlation was observed between the phenolic and flavonoid contents and antioxidant tests (DPPH, FRAP, and ABTS), indicating that these compounds are likely responsible for the observed bioactivity. These findings support the traditional use of W. saharae and highlight its potential as a source of natural therapeutic compounds.