Synthesis of flavonoid-stabilized gold nanoparticles using Citrullus colocynthis for anticancer therapy: experimental...

Citrullus colocynthis is a medicinal plant traditionally used for therapeutic purposes due to its rich content of bioactive flavonoids. Green nanotechnology offers an eco-friendly approach to synthesizing nanoparticles with potential biomedical applications. This study aimed to synthesize and stabilize gold nanoparticles (GNPs) using Citrullus colocynthis extract to evaluate their cytotoxic potential against different cancer cell lines. Gold nanoparticles were synthesized via green synthesis and further stabilized using polyethylene glycol (PEG) to enhance flavonoid capping. The nanoparticles were characterized using UV-Vis spectroscopy, FTIR, XRD, SEM, EDX, and DLS analyses. Cytotoxicity was evaluated using IC50 determination, MTT assay, and cell adhesion assays in the SF-767, HeLa, and MCF-7 cell lines. Molecular docking and pharmacokinetic studies were conducted to investigate interactions between Citrullus colocynthis-derived flavonoids and the mTOR kinase domain, thereby providing a molecular basis for their anticancer activity. Characterization confirmed the successful synthesis of GNPs and the PEG-assisted stabilization of flavonoids. FTIR analysis confirmed the stabilization of nanoparticles with flavonoids, while DLS and TEM results showed that, after stabilization, the GNPs were below 100 nm in size and exhibited an irregular cuboidal morphology. The stabilized nanoparticles exhibited significantly greater cytotoxicity than crude plant extracts. IC₅₀ values and MTT assays revealed enhanced anticancer activity, while intracellular fluorescence confirmed that nanoparticle accumulation reached a maximum at 15 h. Flavonoid-stabilized GNPs derived from Citrullus colocynthis show promising in vitro anticancer activity and cytotoxic effects compared to crude extracts. These findings highlight the potential of eco-friendly plant-based GNPs as candidates for further investigation in cancer nanomedicines, and in vivo studies are required before any therapeutic application can be inferred.