Bioactivity Assessment of Liposome-Encapsulated Alhagi maurorum Extract: Antioxidant and Antibacterial Activities

Abstract

Alhagi maurorum is a medicinal plant containing diverse bioactive compounds with potential antioxidant and antibacterial properties. However, the limited aqueous dispersibility and stability of some plant-derived compounds may restrict their functional applications. In the present study, aerial parts of A. maurorum were extracted using 80% methanol and incorporated into phospholipid-based liposomes prepared by the thin-film hydration method. The physicochemical properties of the extract-loaded liposomes were characterized in terms of particle size, polydispersity index, zeta potential, and encapsulation efficiency. The antioxidant activity of the free and liposome-encapsulated extracts was evaluated using DPPH, ABTS, and FRAP assays. Antibacterial activity was investigated against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 using inhibition-zone measurements, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. The extract-loaded liposomes exhibited nanoscale particle size, relatively narrow size distribution, and effective encapsulation of the plant extract. Liposomal incorporation enhanced the antioxidant activity of the extract, as indicated by improved radical-scavenging and reducing responses compared with the free extract. Similarly, the liposome-encapsulated extract produced greater antibacterial activity, characterized by larger inhibition zones and lower MIC and MBC values against the tested bacterial strains. The findings demonstrate that liposomal encapsulation can improve the antioxidant and antibacterial performance of A. maurorum extract and provide a promising approach for the delivery of plant-derived bioactive compounds.