Synthesis of novel MgO-ZnO nanocomposite using Pluchea indica leaf extract and study of their biological activities

The biosynthesis of bimetallic nanoparticles using plant extracts has garnered significant attention due to their eco-friendly and cost-effective nature. This study aimed to biosynthesize magnesium oxide-zinc oxide nanocomposite (MgO-ZnO nanocomposite) using Pluchea indica leaf extract for the first time, with a focus on characterizing its physicochemical properties and evaluating its biological activities. The biosynthesized MgO-ZnO nanocomposite was fully characterized, revealing an absorbance peak at 300 nm using UV-vis spectroscopy. Transmission electron microscopy (TEM) confirmed particle stability within the size range of 5-35 nm. Cytotoxicity analysis on the Wi 38 normal cell line demonstrated an IC₅₀ value of 179.13 µg/mL, indicating good biosafety. The nanocomposite exhibited potent anticancer activity, with IC₅₀ values of 73.61 µg/mL and 31.25 µg/mL against Hep-G2 and MCF-7 cancer cell lines, respectively. Antibacterial assays revealed activity against Klebsiella pneumoniae, Escherichia coli, Bacillus cereus, Staphylococcus aureus, and Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 31.25 to 250 µg/mL. Furthermore, the nanocomposite displayed antioxidant activity with an IC₅₀ value of 175 µg/mL, as determined by the DPPH assay. In conclusion, the successful synthesis of the MgO-ZnO nanocomposite using P. indica leaf extract demonstrates its potential as a safe and effective agent for concentration-dependent antioxidants, antibacterial, and anticancer applications. This study highlights the versatility of plant-mediated biosynthesis in developing functional nanomaterials for biomedical use.