Antioxidant and anti-inflammatory activities of green synthesized magnesium oxide nanoparticles using Moringa stenopetala leaf extract

The increasing prevalence of chronic diseases driven by oxidative stress and inflammation has increased the demand for novel, safe, and effective therapeutic agents. Green nanotechnology offers an eco-friendly approach for synthesizing biocompatible nanoparticles with enhanced activities. This study aimed to synthesize magnesium oxide nanoparticles (MgO-NPs) using Moringa stenopetala leaf aqueous extract and evaluate their physicochemical properties and antioxidant and anti-inflammatory activities. The synthesized MgO NPs were characterized using UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Antioxidant activities were assessed using DPPH and hydrogen peroxide (H₂O₂) scavenging assays, while anti-inflammatory potential was evaluated through RBC membrane stabilization and antiplatelet aggregation assays. UV-Vis spectroscopy confirmed the formation of MgO-NPs, with a characteristic absorption peak at 275 nm. XRD analysis revealed a crystalline face-centered cubic structure with an average crystallite size of 27.9 nm. FTIR spectroscopy confirmed the presence of phytochemical functional groups responsible for capping and stabilization of the NPs. The SEM micrographs revealed a primarily spherical morphology. The synthesized MgO-NPs exhibited effective DPPH radical scavenging (IC₅₀ = 112.03 µg/mL), comparable to that of ascorbic acid (IC₅₀ = 118.29 µg/mL, p = 0.203). In the H₂O₂ scavenging assay, the NPs showed moderate activity (IC₅₀ ≈ 78 µg/mL), although this was lower than that of ascorbic acid (IC₅₀ ≈ 30 µg/mL, p > 0.05), reflecting assay-dependent differences in antioxidant mechanisms. In the RBC membrane stabilization assay, the NPs exhibited concentration-dependent anti-inflammatory activity. At 300 µg/mL, they exhibited 69.5% inhibition, comparable to the standard drug indomethacin (68.8%) at the same concentration (p > 0.05), with a maximum inhibition of 75.3% at 500 µg/mL. Additionally, MgO-NPs exhibited dose- and time-dependent inhibition of CaCl₂-induced platelet aggregation, with an efficacy comparable to that of indomethacin. The green-synthesized MgO-NPs harnessed the rich phytochemical reservoir of M. stenopetala. They exhibit promising antioxidant and anti-inflammatory activities in vitro, positioning them as potential nanotherapeutic candidates for further investigation in inflammatory disorders and oxidative stress-related conditions.