Biosynthesis of ZnO Nanoparticles Using Washingtonia filifera Seed Extract and Assessment of Their Anti-Inflammatory and Antimicrobial Efficacy

Abstract

The green synthesis of nanoparticles represents an eco-friendly and sustainable alternative to conventional chemical and physical synthesis methods. This approach minimizes the use of hazardous chemicals and leverages biological resources, aligning with the principles of green chemistry. This study aimed to characterise the green synthesised ZnONPs and evaluate their antimicrobial and anti-inflammatory activities. ZnONPs were synthesised using Washingtonia filifera seed extract and characterised using Scanning Electron Microscopy (SEM), UV–Vis spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, energy-dispersive spectroscopy (EDX), and X-ray diffraction (XRD). Their antimicrobial activity against bacteria and fungi, as well as their anti-inflammatory potency, were assessed. SEM data revealed that the ZnONPs, fabricated with palm seed extract metabolites, were spherical with an average size of 50 nm. FT-IR analysis identified varied absorption peaks related to the functional groups of the plant extract and nanoparticles. The antimicrobial activ- ity was dose-dependent, with Staphylococcus aureus and Escherichia coli showing inhibition zones of 8.5 ± 0.7 mm and 11.8 ± 0.3 mm, respectively, at 500 μg/mL. Pseudomonas aeruginosa exhibited a notable inhibition zone of 20.4 ± 0.7 mm. The ZnONPs also inhibited fungal mycelium growth. The in vitro anti-inflammatory activity of ZnONPs showed a concen- tration-dependent increase, with an 89.15% inhibition of RBC haemolysis at 110 μg/mL. The green synthesised ZnONPs demonstrated significant antimicrobial activity against clinical pathogens and potent anti-inflammatory effects, suggesting that this eco-friendly method could be a promising strategy for developing versatile biomedical products.