Phytochemical profiling, metabolomics, and molecular docking studies of Atriplex halimus aerial parts revealing potential insecticidal activity against the malaria vector Anopheles pharoensis

Abstract

Atriplex halimus is traditionally used in folk medicine for the treatment of skin infections, inflammation, and parasitic disorders. The aerial parts of A. halimus were extracted with 70% methanol and fractionated into dichloromethane (DCM), ethyl acetate (EtOAc), n-butanol (BuOH), and aqueous fractions. Comprehensive UPLC/MS profiling identified seventy-eight secondary metabolites, predominantly flavonoids and their derivatives, followed by triterpenoids and minor constituents. The antimicrobial activities of the extract and its fractions were assessed against Staphylococcus aureus and Escherichia coli. The methanol extract (12.0 and 30.0 mm) and the EtOAc fraction (14.0 and 22.0 mm) exhibited the strongest inhibitory effects. Repellent bioassays against Anopheles pharoensis starved females demonstrated solvent- and dose-dependent variations, with the DCM fraction at 6.67 mg/cm² achieving the highest repellency (81.92%). Molecular docking studies were further conducted to elucidate the interactions responsible for the observed antimicrobial and insecticidal activities. In conclusion, these findings highlight A. halimus aerial parts as a rich source of bioactive metabolites with dual antimicrobial and mosquito-repellent potential, supporting their application in natural product-based vector control strategies.