LC-MS/MS profiling and immunomodulatory potential of green-synthesized zinc oxide nanoparticles using Cordia sebestena leaves against chromium-induced acute lung injury in rats

Abstract

This study evaluates the green synthesized zinc oxide nanoparticles (ZnO NPs) using Cordia sebestena leaves (CS) methanolic extract and evaluates their immunomodulatory potential in treating chromium-induced acute lung injury (ALI) in a rat model. A 3² full factorial design, utilizing response surface methodology, was utilized to optimize key parameters, including extract amount, metallic salt concentration, and pH, to control nanoparticle size, polydispersity index, and zeta potential. The optimal formulation (5 g plant extract, 5 g zinc acetate, pH 11) achieved an overall desirability of 0.996. UV–Visible spectroscopy confirmed a characteristic peak at 360 nm (optical band gap: 3.2 eV), while Fourier Transform Infrared analysis identified biofunctional groups stabilizing the nanoparticles. Transmission electron microscopy revealed hexagonal particles with a crystallite size of around 80 nm, consistent with dynamic light scattering data. Thermogravimetric analysis demonstrated high thermal stability. CS-ZnO NPs significantly enhanced lung antioxidant capacity (increased GSH levels) and reduced oxidative stress (MDA), pro-inflammatory cytokines (TNF-α, IL-17), and signaling molecules (Akt, PI3K). AMPK activation was also markedly improved in the CS-ZnO NPs-treated group. Dereplication analysis of the Cordia sebestena leaves methanolic extract was conducted using Q-TOF LC/MS/MS; metabolic profiling identified 33 compounds, which are classified into various chemical groups, including flavonoids, phenolic acids, stilbenes, organic acids, and fatty acids. These findings suggest that CS-ZnO NPs exhibit potent pulmonary protective effects against chromium-induced ALI through their antioxidant, anti-inflammatory, and immunomodulatory properties, underscoring their potential for sustainable biomedical applications.