Nanoencapsulation of hydroxytyrosol extract of fermented olive leaf brine using proniosomes

Olive leaves are rich in bioactive compounds with potential health benefits; however, their limited bioavailability and stability hinder their effective utilization. Emerging technologies, nanocarrier-based delivery systems, have shown promise in enhancing these properties.

The optimal conditions for proniosome formulation were 50 rpm rotational speed and 35 °C, achieving 81.20 ± 0.80% encapsulation efficiency. Particle sizes ranged from 188.6 to 248.9 nm, with a zeta potential of ~-30 mV, indicating high stability and resistance to aggregation. Advanced instrumental analysis confirmed interactions between the extract and proniosome components. After 30 days at 4 °C, extract-loaded proniosomes maintained better homogeneity and lower polydispersity index. Cytotoxicity studies showed that both the extract and its proniosomal form were nontoxic to HEK293T cells up to 200 μg mL^-1. In zebrafish assays, minimal larval mortality was observed up to 3200 μg mL^-1 for the extract, while no mortality occurred up to 1600 μg mL^-1 for the proniosomal extract, highlighting its improved safety profile.

The findings from this research could contribute to the advancement of sustainable and health-promoting food innovations by integrating cutting-edge nanotechnology-driven encapsulation strategies into plant-based food formulations. © 2025 Society of Chemical Industry.