Antioxidant Effect of Hydroxytyrosol, Hydroxytyrosol Acetate and Nitrohydroxytyrosol in a Rat MPP+ Model of Parkinson's Disease.

3,4-Dihydroxyphenyl ethanol, known as hydroxytyrosol (HTy), is a phenylpropanoid found in diverse vegetable species. Several studies have demonstrated that HTy is a potent antioxidant. Thus, our study is aimed to evaluate the antioxidant effect of HTy and its derivatives, hydroxytyrosol acetate (HTyA) and nitrohydroxytyrosol (HTyN), in a model of oxidative stress induced by 1-methyl-4-phenylpyridinium (MPP+) in rats. Rats were administered intravenously (i.v.) in the tail with 1 mL saline solution or polyphenol compound (1.5 mg/kg) 5 min before intrastriatal infusion of 10 µg MPP+/8 µL. We found that rats injured with MPP+, pretreatment with HTy, HTyA or HTyN significantly decreased ipsilateral turns. This result was consistent with a significant preservation of striatal dopamine levels and decreased lipid fluorescence products (LFP), a marker of oxidative stress. Brain GSH/GSSG ratio, from rats pretreated with HTy or HTyN showed a significant preservation of that marker, decreased as a consequence of MPP+-induced oxidative damage. These results show an antioxidant effect of HTy, HTyA and HTyN in the MPP+ model of Parkinson's disease in the rat.