Antioxidant and neuroprotective effect of PSE-1 against oxidative stress-induced cytotoxicity in N18-RE-105 cells

Neurodegenerative conditions such as the Alzheimer and Parkinson diseases, areassociated with the production of reactive oxygen species and resultant oxidative stress.Glutamate is the major excitatory neurotransmitter of the central nervous system and may induce cytotoxicity through persistent activation of glutamate receptors and through oxidative stress mechanisms. On the basis of this information, we established a screening system using N18-RE-105 cells to identify therapeutic agents that can protect cells from glutamate toxicity. During the course of our screening program, we recently isolated an active compound, 8,13-dihydroxy-9,11-octadecadienoic acid (PSE-1), from peanut sprouts, which prevents glutamate-induced cell death. The chemical structure of PSE-1 was identified using spectroscopic methods and by comparison with the value in the literature. The antioxidant and neuroprotective effects of PSE-1 were evaluated using the oxygen radical absorbance capacity assay, Comet assay, the 3-(4,5-dimethylthiazol-2-yl)-2,5,-diphenyltetrazolium bromide reduction assay, the lactate dehydrogenase release assay, a morphological assay and Hoechst 33342 staining. The results of the assays demonstrate that PSE-1 has neuroprotective effects and that PSE-1 could be a new potential chemotherapeutic agent against neuronal diseases.   Key words: Glutamate, PSE-1, peanut sprout, antioxidant, neuroprotective, N18-RE-105 cells.