Biogenic α-Fe2O3 nanoparticles from Sorghum bicolor leaf extracts and assessment of the anticancer and antioxidant properties

Abstract

Abstract The synthesis of nanomaterials has recently shifted toward environmentally benign approaches that mitigate the drawbacks of conventional chemical methods. In this context, plant-mediated green synthesis offers a sustainable and versatile alternative for producing nanoparticles with unique physicochemical properties and diverse applications. This study presents the green synthesis of hematite iron oxide nanoparticles (α-Fe2O3 NPs) using aqueous leaf extracts of Sorghum bicolor. The resulting nanoparticles were characterized using X-ray diffraction (XRD), UV–visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). XRD analysis confirmed the formation of a crystalline rhombohedral hematite phase with an average crystallite size of 46.8 nm. SEM and TEM images revealed predominantly spherical particles with evident agglomeration, while EDX analysis confirmed iron (Fe) and oxygen (O) as the primary elemental constituents. Antioxidant activity assessed via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay showed a concentration-dependent radical scavenging effect, with higher α-Fe2O3 NP concentrations required to achieve 50% inhibition. Cytotoxicity studies on HeLa (cancer) and HEK293 (normal) cell lines indicated selective toxicity, with the nanoparticles preferentially affecting cancer cells while sparing healthy ones. Although the α-Fe2O3 NPs exhibited lower potency compared to the standard chemotherapeutic agent 5-fluorouracil, their concentration-dependent reduction in cell viability supports the hypothesis that cancer cells are particularly vulnerable to disruptions in iron homeostasis. This cost-effective and eco-friendly synthesis method underscores the potential of Sorghum bicolor-mediated α-Fe2O3 nanoparticles for future biomedical applications.

Keywords

• Green chemistry
• Iron oxide
• Biosynthesis
• Cytotoxicity
• Antioxidants