Unveiling the biological applications of biosynthesized magnesium oxide-manganese oxide-gold ternary nanocomposite (MgO–MnO–Au TNC) by Mangifera indica peel: characterization, antimicrobial, antioxidant and anticancer activities

In the current study, a magnesium oxide–manganese oxide–gold ternary nanocomposite (MgO–MnO–Au TNC) was biosynthesized using Mangifera indica peel extract through an eco-friendly, one-pot approach. UV–visible spectroscopy confirmed the presence of MgO, MnO, and Au within the ternary nanocomposite, showing two absorption bands corresponding to the combined optical effects of the components, while DLS and TEM analysis showed an average particle size of approximately 120 nm with a spherical morphology. XRD analysis demonstrated distinct crystalline peaks corresponding to MgO, MnO, and Au, affirming the polycrystalline nature of the TNC. Biological evaluations demonstrated that MgO–MnO–Au TNC exhibited broad-spectrum antibacterial activity, with MIC values of 62.5 μg/mL against Pseudomonas aeruginosa and 250 μg/mL against Staphylococcus aureus . Antioxidant activity was also remarkable, with IC 50 values of 149.6 μg/mL (DPPH) and 242.1 μg/mL (APTS). Cytotoxicity assessment revealed an IC 50 of 193 μg/mL against normal Wi-38 cells, whereas MCF-7 and Hep-G2 cancer cell lines exhibited IC 50 values of 26.43 μg/mL and 84.13 μg/mL, respectively, indicating selective cytotoxicity with selectivity indices of 7.32 (MCF-7) and 2.30 (Hep-G2). In conclusion, these findings suggest that MgO–MnO–Au TNC is a promising candidate for antimicrobial, antioxidant, and anticancer applications, warranting further investigation into its underlying mechanisms and therapeutic potential.