Phytochemical‐Mediated Biosynthesis of Nickel Oxide Nanoparticles From Argemone mexicana (L.) Root Extracts and Their Biomedical Applications

Phytochemistry‐mediated nanoparticle synthesis offers an eco‐friendly and sustainable approach for biomedical applications. In this novel study, nickel oxide nanoparticles (NiONPs) were successfully biosynthesized using the root extract of Argemone mexicana (L.). The synthesized NiONPs exhibited an absorption peak at 330 nm in the UV–vis spectrum, while FTIR analysis confirmed the presence of various functional groups responsible for nanoparticle stabilization. XRD analysis revealed a crystalline structure, and FESEM and HR‐TEM micrographs indicated spherical morphology and an average particle size of 18.5 nm, with elemental nickel (72.3 wt%) confirmed by EDX and the zeta potential analyses of ‐12.5 mV, consistent with colloidal stability. The biosynthesized NiONPs displayed potent antioxidant activity with the maximum ABTS (72.53 ± 1.91%) radical scavenging. Antibacterial evaluation demonstrated broad‐spectrum activity, with Escherichia coli showing the highest inhibition zone (17.38 ± 1.42 mm). Anti‐inflammatory activity assays revealed COX‐2 inhibition of 76.39 ± 2.17%, respectively. Furthermore, cytotoxicity studies against MCF‐7 cells, using the MTT assay, showed a significant reduction in cell viability (36.59 ± 1.73%) at 100 µg/mL. These findings indicate that A. mexicana ‐mediated NiONPs exhibit potent antioxidant, antibacterial, anti‐inflammatory, and anticancer properties, suggesting their potential as therapeutic nanomaterials.