Protective effects of Auranofin on the 6-hydroxydopamine model of Parkinson's disease in rats

Auranofin (AU) presents anti-inflammatory effects and was shown to have a neuroprotective action. The objectives were to investigate the actions of AU in the 6-OHDA model of Parkinson’s disease (PD). Methods: Male Wistar rats were distributed into sham-operated (SO, control), untreated 6-OHDA lesioned and 6-OHDA lesioned, and treated with AU (3 and 10 mg/kg, p.o. for 2 weeks) groups. Then, animals were euthanized, the striatum dissected and processed for measurements of dopamine (DA) and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), as well as immunohistochemical assays for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and the Nuclear factor erythroid 2-related factor 2 (Nrf2). The influence of AU on the activation of the brain NrF2 was also pursued by molecular docking experiments. Results: While the 6-OHDA lesioned rats presented a decrease in the striatal DA and DOPAC concentrations, these effects were prevented after AU treatment. The 6-OHDA group showed increased expressions of iNOS and COX-2 and these effects were highly prevented by AU. While Nrf2 expression was significantly decreased in the 6-OHDA lesioned animals, values came back to those close to the SO group after AU treatment. Auranofin may bind to the Kelch domain of the Kelch-like ECH-associated Protein 1 (Keap1) and possibly inhibit Keap1/Nrf2 interaction. Significance: AU by decreasing iNOS and COX-2 expressions and by increasing the expression of Nrf2, emerge as a potential neuroprotective drug for the treatment of PD.