Chemical Profiling and In Vitro Assessment of Antioxidant and Antimicrobial Properties of Algerian Erica arborea L. Extracts, Strengthened by Molecular Modeling Analysis

This study aimed to valorize Erica arborea L. collected in Algeria by characterizing its chemical composition and assessing the biological potential of its organic extracts. The aerial nonflowering parts were extracted using solvents of increasing polarity, allowing evaluation of chemical and biological properties of extracts. Phytochemical assays revealed that the ethyl acetate (EtOAc) fraction contained the highest levels of total polyphenols (419.58 ± 1.89 µg GAE/mg), flavonoids (174.57 ± 1.93 µg QE/mg), and flavonols (61.64 ± 2.49 µg QE/mg). GC–MS profiling confirmed the presence of several bioactive constituents, supporting its rich chemical composition. Antioxidant activity highlighted the superiority of EtOAc extract, with IC ₅₀ of 5.07 ± 0.63 μg/mL in the ABTS ^•+ assay, 26.96 ± 1.16 μg/mL in the DPPH ^• assay, and an A _0.5 of 18.14 ± 0.57 μg/mL in the FRAP test, while the phenanthroline assay showed strong reducing power across all extracts ( A _0.5  = 1.25 ± 0.05–6.72 ± 0.15 μg/mL). Antimicrobial activity revealed that the EtOAc fraction exhibited notable activity against Staphylococcus aureus (19.33 ± 0.57 mm) and Bacillus subtilis (19.0 ± 1.0 mm), while all fractions showed antifungal activity against Candida albicans and Fusarium oxysporum . Molecular docking on xanthine oxidase and DNA gyrase (GyrA and GyrB) revealed favorable interactions of several metabolites, supporting the antioxidant and antibacterial activities observed experimentally.