Neuroprotective effects of polyphenol-rich extracts obtained from agricultural by-products in an induced cognitive decline model of zebrafish larvae and in human neurons.

Identifier:  imarina:9468901

Handle: https://hdl.handle.net/20.500.11797/imarina9468901

Authors:  Castillo-Moral Á; Tchoumtchoua J; Leonard K; Del Bas JM; Ortega N; Escoté X; Teichenné J

Abstract:
Neurodegenerative diseases are closely associated with chronic neuroinflammation and oxidative stress, which contribute to progressive neuronal dysfunction and cell death. Due to their antioxidant and anti-inflammatory properties, polyphenols have gained attention as potential neuroprotective agents. Agricultural by-products represent a promising and sustainable source of polyphenols, yet their neuroprotective value remains underexplored. In this study, we evaluated four polyphenol-rich extracts derived from red onion peels (ROPE), olive pruning (OPE), vineyard pruning (VPE) and chicory leaves (CLE), obtained by subcritical water extraction. Their effects were tested in two complementary models of neurodegeneration: in vitro human neurons (SH-SY5Y cells) exposed to D-galactose and a basic cognitive decline model of zebrafish larvae exposed to aluminium chloride (AlCl3). All extracts exhibited anti-inflammatory effects in vitro, significantly reducing IL-1β and IL-8 mRNA expression, at doses ranging 12.5-50 μg/mL in cell medium. In the zebrafish model, treatment with 100 μg/mL ROPE or VPE in medium restored the normal sensorimotor pattern in the Dark-Light-Dark test, while ROPE treatment additionally rescued basal startle responses and enhanced habituation indexes, even surpassing healthy control larvae. Overall, these results highlight the potential of polyphenol-rich agri-food extracts, particularly ROPE, as neuroprotective and cognitive-enhancing compounds and support their further investigation as natural and sustainable interventions to slow or prevent neurodegenerative processes.