Green-synthesized gold nanoparticles exhibit neuroprotective activity against oxidative stress-induced damage in SH-SY5Y cells

Abstract

Neurodegenerative diseases such as Alzheimer’s are strongly driven by oxidative stress, yet existing antioxidant therapies are limited by low bioavailability and poor blood–brain barrier (BBB) penetration. In this study, we report the green synthesis of gold nanoparticles (AuNPs) using three distinct phytochemicals (morin hydrate, polydatin, and berberine chloride) and demonstrate their potent neuroprotective effects against oxidative stress-induced damage in SH-SY5Y cells. Synthesized AuNPs were characterized via UV–visible spectroscopy, DLS, SEM, FTIR, and zeta potential analysis. Antioxidant potential was assessed using DPPH, WST-1, TBARS, DCFH-DA assays, and confocal microscopy in paraquat-induced oxidative stress in SH-SY5Y cells. All phytochemically synthesized AuNPs demonstrated excellent colloidal stability (zeta potential > ± 30 mV), spherical-to-cuboidal morphology, and sizes < 150 nm. They exhibited superior ROS scavenging capacity and biocompatibility relative to conventional AuNPs and parent phytochemical compounds. Notably, polydatin-AuNPs significantly reduced lipid peroxidation and cellular ROS to baseline levels. These results suggest green-synthesized AuNPs as promising therapeutic nanoplatforms for mitigating oxidative stress in neurodegenerative disorders.