The total GSH depletion observed in the substantia nigra (SN) appears to be responsible for subsequent oxidative stress (OS), mitochondrial dysfunction, and dopaminergic cell loss in patients with Parkinson’s disease. A strategy to prevent the OS of dopaminergic cells in the SN may be the use of chemopreventive agents as inducers of endogenous GSH, antioxidant and phase 2 enzymes. In this study, we demonstrated that treatment of the dopaminergic‐like neuroblastoma SH‐SY5Y cell line with sulforaphane (SF), a cruciferous vegetables inducer, resulted in significant increases of total GSH level, NAD(P)H : quinone oxidoreductase‐1, GSH‐transferase and ‐reductase, but not GSH‐peroxidase, catalase and superoxide dismutase activities. Further, the elevation of GSH levels, GSH‐transferase and NAD(P)H:quinone oxidoreductase‐1 activities was correlated to an increase of the resistance of SH‐SY5Y cells to toxicity induced by H2O2 or 6‐hydroxydopamine (6‐OHDA). The pre‐treatment of SH‐SY5Y cells with SF was also shown to prevent various apoptotic events (mitochondrial depolarization, caspase 9 and 3 activation and DNA fragmentation) and necrosis elicited by 6‐OHDA. Further, the impairment of antioxidant capacity and reactive oxygen species formation at intracellular level after exposure to 6‐OHDA was effectively counteracted by pre‐treatment with SF. Last, both the cytoprotective and antioxidant effects of SF were abolished by the addition of buthionine sulfoximine supporting the main role of GSH in the neuroprotective effects displayed by SF. These findings show that SF may play a role in preventing Parkinson’s disease.

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The amyloid-beta (A beta) peptide (1-42) aggregation into oligomeric and fibrillar species affects neuronal viability, having a causal role in the development of Alzheimer's disease. Among dietary anthocyanins, cyanidin 3-O-glucoside (Cy-3G) and its metabolites, such as protocatechuic acid (PA), have gained attention as potential neuroprotective agents. In this in-vitro study, we demonstrated that Cy-3G, but not PA, can inhibit A beta1-42 spontaneous aggregation using thioflavin T fluorescence assay and transmission electron microscopy. Furthermore, treatment of human neuronal SH-SY5Y cells with Cy-3G during oligomeric and fibrillar A beta1-42 treatment prevents neuronal viability loss. These protective effects were still evident when Cy-3G treatment was initiated after the appearance of oligomeric A beta1-42 neurotoxicity. Taken together, these results suggest that Cy-3G may protect and rescue the neuronal cells from toxicity induced by A beta1-42.

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