Ellagic Acid-Wrapped Gold Nanoparticles: Evaluation of Antimicrobial, Antioxidant, Anti-Inflammatory, and Cytotoxicity Effects of KB Cells

The green synthesis of metal nanoparticles using plant-based molecules is gaining attention for its potential in biomedical applications. The aim of present study the eco-friendly synthesis of gold nanoparticles (AuNPs) using ellagic acid, a natural antioxidant, which acted as both reducing and capping agent. The successful synthesized ellagic acid-coated AuNPs (EA-AuNPs) was indicated by a colour change to dark brown and confirmed through UV-visible spectroscopy with a peak at 587.5 nm. Transmission electron microscopy (TEM) revealed long rod-shaped nanoparticles ranging from 50 to 70 nm in size, and energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of Au, C, Cl, and N elements. Zeta potential analysis showed a stable surface charge of -17.7 mV. EA-AuNPs exhibited strong antibacterial activity, including a 37.26 ± 0.9 mm inhibition zone against Klebsiella pneumoniae at 100 µg/mL and minimum inhibitory concentration (MIC) values below 1 µg/mL against Staphylococcus aureus. The nanoparticles also demonstrated potent antioxidant activity, achieving 91% and 89% radical scavenging in DPPH and ABTS assays, respectively. Anti-inflammatory testing showed 78% membrane stabilization at 200 µg/mL. Moreover, cytotoxicity studies revealed that EA-AuNPs had an IC₅₀ of 59.58 µg/mL against oral epidermoid carcinoma (KB) cells. In-silico analysis also demonstrated a promising binding affinity of -7.3 kcal/mol with Candida albicans, suggesting notable antifungal properties. The present study highlights the multi-functional therapeutic potential of EA-AuNPs in oral health care, offering a biocompatible approach to combat microbial infections, oxidative stress, inflammation, and oral cancer. The integration of both in-vitro and in-silico results supports their future application in dental and oral medicine.