Eco-friendly synthesis, characterization, and anticancer potential of iron oxide nanoparticles derived from <i>Plectranthus amboinicus</i> and <i>Dorstenia foetida</i> plant extracts

Iron oxide nanoparticles (IONPs) were synthesized using a green approach employing methanolic extracts of <i>Plectranthus amboinicus</i> and <i>Dorstenia foetida</i>. The color change from brown to black indicated IONP formation. Characterization included Ultraviolet–Visible Spectroscopy (characteristic peaks at 340 nm for <i>P. amboinicus</i> and ∼280 nm for <i>D. foetida</i> IONPs), Fourier Transform Infrared Spectroscopy (confirming hydroxyl groups and Fe-O bonds), X-ray Diffraction (crystallite sizes 26-30 nm), Proton Nuclear Magnetic Resonance Spectroscopy (suggesting phenolic involvement in reduction/stabilization), Energy-Dispersive X-ray Analysis (confirming iron and oxygen), and Field Emission Scanning Electron Microscopy (revealing diverse morphologies). The IONPs exhibited superior anticancer activity against THP-1 leukemia and Calu-3 lung cancer cells compared to parent extracts. <i>P. amboinicus</i> IONPs showed the highest efficacy (IC50: 25 μg/ml against THP-1, 34 μg/ml against Calu-3). Flow Cytometry revealed IONP-induced apoptosis. Analysis of Variance, t-tests, and Chi-square tests supported the enhanced anticancer potential of the green-synthesized IONPs. This eco-friendly synthesis offers a sustainable method for producing IONPs with promising therapeutic applications.