Bioactive Potential and Chemical Composition of Vitex agnus-castus L. Leaf Extracts Collected in Algeria: A Combined In Vitro and In Silico Approach

Abstract

Vitex agnus-castus L., a medicinal plant widespread in the Middle East and Europe, is traditionally used to treat various disorders. In this study, extracts from its leaves, collected in Algeria, were evaluated for their antioxidant, enzymatic, and antibacterial activities through in vitro and in silico studies. The hydroalcoholic extract was fractionated using solvents of varying polarity to isolate bioactive compounds with potential biological effects. Notable levels of total phenolics, flavonoids, and flavonols were detected in the dichloromethane (CH2Cl2) and ethyl acetate (EtOAc) extracts. NMR and GC-MS were used to identify metabolites in the extracts, which were discussed in relation to their biological activities. Antioxidant assays showed that the EtOAc extract had a remarkable effect, particularly in the DPPH• free radicals test (IC50 = 15.68 ± 1.51 μg/mL), while enzymatic assays revealed that the dichloromethane extract moderately inhibited butyrylcholinesterase (IC50 = 133.54 ± 1.45 μg/mL). Antibacterial assays showed that the extracts inhibited the growth of Staphylococcus aureus, Bacillus subtilis, and Escherichia coli strains, with the most significant effect observed for the n-hexane extract, especially against S. aureus and B. subtilis (respectively, 22.33 ± 0.47 and 18.33 ± 0.47 mm diameters). These outcomes were validated via molecular docking simulations on three DNA gyrase enzymes: 3G7E (from E. coli), 3G75 (from S. aureus), and 4DDQ (from B. subtilis), revealing that linolenic and palmitic acids, as well as phytol significantly interacted with these enzymes, showing varying binding affinities and suggesting antibacterial potential against the targeted species E. coli and S. aureus. These findings highlight the potential therapeutic use of V. agnus-castus leaves, encouraging further research into their applicability in the development of plant-derived drugs.