Journal of Neurochemistry 2013-01-01

Vinpocetine and α-tocopherol prevent the increase in DA and oxidative stress induced by 3-NPA in striatum isolated nerve endings.

Nieves Herrera-Mundo, María Sitges

Index: J. Neurochem. 124(2) , 233-40, (2013)

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Abstract

Vinpocetine is a neuroprotective drug that exerts beneficial effects on neurological symptoms and cerebrovascular disease. 3-nitropropionic acid (3-NPA) is a toxin that irreversibly inhibits succinate dehydrogenase, the mitochondrial enzyme that acts in the electron transport chain at complex II. In previous studies in striatum-isolated nerve endings (synaptosomes), we found that vinpocetine decreased dopamine (DA) at expense of its main metabolite 3,4-dihydroxyphenylacetic acid (DOPAC), and that 3-NPA increased DA, reactive oxygen species (ROS), DA-quinone products formation, and decreased DOPAC. Therefore, in this study, the possible effect of vinpocetine on 3-NPA-induced increase in DA, ROS, lipid peroxidation, and DA-quinone products formation in striatum synaptosomes were investigated, and compared with the effects of the antioxidant α-tocopherol. Results show that the increase in DA induced by 3-NPA was inhibited by both 25 μM vinpocetine and 50 μM α-tocopherol. Vinpocetine, as α-tocopherol, also inhibited 3-NPA-induced increase in ROS (as judged by DCF fluorescence), lipid peroxidation (as judged by TBA-RS formation), and DA-quinone products formation (as judged by the nitroblue tetrazolium reduction method). As in addition to the inhibition of complex II exerted by 3-NPA, 3-NPA increases DA-oxidation products that in turn can inhibit other sites of the respiratory chain, the drop in DA produced by vinpocetine and α-tocopherol may importantly contribute to their protective action from oxidative damage, particularly in DA-rich structures.© 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.