Syzygium cumini-mediated Green Synthesis of Magnesium Oxide Nanoparticles and Evaluation of their Antibacterial, Antileishmanial, and Antioxidant Activities

Green protocols for the synthesis of nanoparticles have gained significant attention due to their environmental friendliness, ease, and cost-effectiveness. The present study focused on the synthesis of magnesium oxide nanoparticles (MgO-NPs) using an aqueous leaves extract of Syzygium cumini plant, and the antimicrobial potential of the synthesized NPs. Methods: The synthesis of MgO-NPs was achieved by mixing a solution of magnesium nitrate (Mg (NO3)2 with an aqueous extract obtained from S. cumini leaves to reduce the Mg+ ions. These NPs were characterized by X-ray diffraction (XRD), Fourier-Transform Infrared (FTIR) Spectroscopy analysis, Scanning electron microscopy (SEM), and Energy-dispersive X-ray (EDX) analysis. Results: The transformation in color of the solution from yellow to deep brown along with the UV absorption peak at 294 nm showed the effective synthesis of MgO-NPs. SEM and XRD data revealed cubic-shaped NPs with an average size of 23.73 nm. EDX analysis confirmed the presence of magnesium and oxygen in the sample at 31.85% and 35.11% weight percentages, respectively. The antibacterial evaluation demonstrated effectiveness against the gram-negative strains Citrobacter koseri and Pseudomonas aeruginosa, with inhibition zones of 28.1 ± 1.25 mm and 27.8 ± 1.25 mm, respectively. MgO-NPs also showed antileishmanial potential against Leishmania tropica promastigotes (68.41 ± 0.05% inhibition at 1000µg/ml). Furthermore, the NPs exhibited antioxidant properties (75.12 ± 4.29% at 1 mg/ml) as determined by the DPPH radical scavenging assay. Conclusions: MgO-NPs synthesized using S. cumini plant leaves extract hold promises as agents for antibacterial, antileishmanial, and antioxidant applications.