Antibiofilm and antimicrobial activity studies of the essential oil, extract, and green synthesized silver nanoparticles from the leaves of Syzygium stocksii

This study investigates the phytochemical composition and biological potential of the leaves of Syzygium stocksii. For the first time, the presence of β-Ocimenes (E and Z isomers) was identified in the leaf extracts. The total phenolic and flavonoid contents were quantified, and the extracts demonstrated notable antioxidant activity. The ethanolic extract was further applied in the green synthesis of silver nanoparticles (AgNPs), which were evaluated for their antimicrobial and antibiofilm properties. Antimicrobial assays were performed against Acinetobacter baumannii, Pseudomonas aeruginosa, Bacillus cereus, Streptococcus mutans, and Candida albicans, revealing S. mutans and A. baumannii as the most sensitive to the essential oils. Importantly, the AgNPs exhibited strong antibiofilm activity against P. aeruginosa. These findings not only broaden the phytochemical profile of S. stocksii but also highlight its potential as a source of natural antioxidants, antimicrobials, and eco-friendly nanomaterials with promising biomedical applications.