Characterization of Walnut Oil and Evaluation of Its Neuroprotective Effects in an In Vitro Model of Parkinson’s Disease

Parkinson’s disease (PD) is a common neurodegenerative disorder marked by the degeneration of dopaminergic neurons and the buildup of α-synuclein aggregates. The current treatments focus on symptom relief, with no drugs available to halt disease progression. This has prompted interest in plant-based extracts as alternative therapies. This study examines the neuroprotective and antioxidant effects of walnut oil (WO), extracted from Juglans regia L., in an in vitro PD model using the neurotoxin rotenone (ROT). WO, rich in polyunsaturated fatty acids (PUFAs), including linoleic acid (LA) and α-linolenic acid (ALA), together with minor bioactive components, is known for its neuroprotective properties. Using human HMC3 microglial and SH-SY5Y neuroblastoma cells, we tested WO’s effects on ROT-induced toxicity. The experiments were performed at different time points. The results showed that the co-administration of WO with ROT significantly improved cell viability and reduced reactive oxygen species (ROS) levels. Additionally, conditioned media from WO-treated HMC3 cells enhanced SH-SY5Y cell survival, indicating positive microglia–neuron interactions. Cell viability appeared to be concentration- and time-dependent. These findings highlight WO’s potential, mainly due to its PUFA content, as a promising candidate for preventing neurodegenerative diseases like PD; they underscore the potential of WO content in food for the prevention of neurodegenerative diseases such as PD.