El Sayed_2025_Fitoterapia_187_106943

This study focused on the green synthesis of zinc oxide nanoparticles (ZnONPs) using Gmelina arborea Roxb (GA) leaf extract. Both the extract and the green-synthesized ZnONPs (GSNPs) were evaluated for their biological activities against key health conditions; Alzheimer's disease, diabetes, and inflammation. Standard reference drugs;donepezil, sitagliptin, and ibuprofen were included in the respective assays. Successful synthesis of GSNPs was confirmed and characterized using SEM, TEM, FTIR, X-ray diffraction, UV spectroscopy, and zeta potential analysis. The nanoparticles were spherical, with sizes ranging from 8.01 to 18.79 nm, and some agglomerates measuring between 50.27 and 72.50 nm. FTIR analysis indicated effective capping by flavonoids and cinnamic acid derivatives. Zeta potential values ranged from -31.3 to -49.9 mV, suggesting good colloidal stability. GSNPs demonstrated significant anti-acetylcholinesterase (AChE) activity (p < 0.001) compared to donepezil. The IC50 values for GA leaf extract, GSNPs, and donepezil were 113.24 +/- 7.39, 105.1 +/- 3.62, and 49.70 +/- 2.50 microg/mL, respectively. The GSNPs also exhibited a notable anti-inflammatory effect (p < 0.0001), outperforming the GA leaf extract, while the anti-diabetic activity was moderate. HPLC analysis revealed a rich content of phenolics and flavonoids, which are likely involved in the nanoparticle synthesis and biological activities. The environmental sustainability of the entire process-from synthesis to analysis-was evaluated using AGREE software, yielding a high score of 0.88, indicating strong adherence to green chemistry principles. In conclusion, the green synthesis of ZnONPs using Gmelina arborea leaf extract presents an economical and eco-friendly approach, with promising potential for developing therapeutic agents against inflammation-related diseases.