Bioinspired gold nanoparticles synthesized from Persicaria capitata leaves and their antimicrobial and anticancer activities

A green technique that enables one-pot synthesis is the plant-mediated biosynthesis of nanoparticles. Owing to their wide range of applications, the synthesis of gold nanoparticles (AuNPs) using plant extracts has attracted considerable attention in the biomedical field. In this study, the aqueous extract of Persicaria capitata leaves was employed to synthesize AuNPs via a green chemistry approach at room temperature. The formation of AuNPs was confirmed by UV–Vis spectroscopy, which showed a surface plasmon resonance peak at 534 nm. XRD analysis indicated the crystalline nature of the nanoparticles, revealing a cubic close-packed (ccp) phase structure. EDX spectra of P. capitata -derived AuNPs exhibited weak peaks at around 0.25 keV and 0.5 keV, likely due to biomolecules attached to the nanoparticle surface, along with a sharp, intense signal at 2.1 keV that confirmed the presence of elemental gold. TEM examination showed nanoparticles with both spherical and triangular morphologies and FTIR analysis demonstrated the presence of bioactive molecules responsible for reducing Au³⁺ ions during synthesis. For antimicrobial activity, bacterial cultures were grown on soybean casein digest agar medium and fungal cultures on potato dextrose agar medium. The synthesized AuNPs exhibited inhibitory effects against Escherichia coli , Bacillus subtilis , Candida albicans , and Aspergillus oryzae , with zones of inhibition measuring 10.0 mm, 7.0 mm, 15.0 mm, and 10.0 mm, respectively. The anticancer potential of the synthesized AuNPs was evaluated using both in vitro and in vivo experiments. MTT and SRB assays were performed on hepatic (Hep-2) cell lines, while in vivo studies involved induction of cancer in the livers of Swiss albino rats. Parameters such as tumor weight, hemoglobin content, viable and non-viable cells, RBC count, and WBC count were assessed. The results indicated that the AuNPs inhibited cancer cell proliferation and exhibited significant anticancer activity. Future research should focus on elucidating detailed mechanisms, conducting clinical validation, and developing large-scale production strategies to translate these findings into practical biomedical applications.