Gold Nanoparticles Green-Synthesized by the Suaeda japonica Leaf Extract and Screening of Anti-Inflammatory Activities on RAW 267.4 Macrophages

Abstract

Biosynthesis of gold nanoparticles from medicinal plants has become a modern strategy in biomedical research based on their exclusive properties, including specific targeting, lower toxicity, and biocompatibility. In this study, gold nanoparticles, reduced by the Suaeda japonica leaf extract, were promptly validated by UV–visible (UV–Vis) spectroscopy at 548 nm. No additional reducing agents were needed in this kind of a reduction reaction, which provided evidence of green synthesis. Dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDX), field-emission transmission electron microscopy (FE-TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) analyses were used to illustrate the nanoscale characterization of S. japonica gold nanoparticles (Sj-AuNps). Furthermore, the cytotoxicity effect of Sj-AuNps against the RAW 264.7 cell line was determined by performing an MTT assay. We also investigated Sj-AuNps’ anti-inflammatory properties in LPS-induced murine macrophages. These nanoparticles reduced the generation of nitric oxide (NO) and prostaglandin E2 (PGE2) and repressed the expression of the LPS-stimulated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) genes. This study presents a significant biomedical application of S. japonica AuNps. The anti-inflammatory capabilities of Sj-AuNps underline their potential as possible options for suppressing inflammation-mediated diseases.