Síntese biogénica de nanopartículas multifuncionais de óxido de zinco utilizando extrato de Rosmarinus officinalis L.: avaliação abrangente do potencial antibacteriano, antioxidante e antimalárico

This study reports an eco-friendly synthesis of zinc oxide nanoparticles (ZnO-NPs) using Rosmarinus officinalis L. leaf extract as a reducing and stabilizing agent. The extract was characterized by Fourier Transform Infrared (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS). The biosynthesized ZnO-NPs were thoroughly characterized through UV-Vis spectroscopy showing a distinctive absorption peak at 372 nm, FT-IR confirms phytochemical capping, XRD reveals hexagonal wurtzite structure with crystallite size of 42.47 ± 1.20 nm, and SEM/EDX exhibits spherical morphology with high purity. The ZnO-NPs exhibited dose-dependent antibacterial activity against Staphylococcus aureus (24.0 ± 0.5 mm at 100 μg/mL) and Escherichia coli (18.0 ± 0.3 mm), outperforming the crude extract. Antioxidant assays, with ascorbic acid (vitamin C) as a positive control, demonstrated 89.2 ± 2.1% DPPH inhibition (IC50 = 28.4 μg/mL), comparable to ascorbic acid. Notably, ZnO-NPs showed 82.3 ± 3.2% β-haematin inhibition (50 μM), surpassing chloroquine (68.1 ± 2.8%), suggesting antimalarial potential. These findings highlight their potential as multifunctional therapeutic agents with a novel and promising antimalarial application.