Dopamine Receptor Agonists for Protection and Repair in Parkinsons Disease

Giulia      Ferrari-Toninelli; Sara   A.   Bonini; Giovanna      Cenini; Giuseppina      Maccarinelli; Mariagrazia      Grilli; Daniela      Uberti; Maurizio      Memo

Abstract

Dopamine agonists have been usually used as adjunctive therapy for the cure of Parkinsons disease. It is generally believed that treatment with these drugs is symptomatic rather than curative and it does not stop or delay the progression of neuronal degeneration. However, several dopamine agonists of the D2-receptor family have recently been shown to possess neuroprotective properties in different in vitro and in vivo experimental Parkinsons disease models. Here we summarize some recent molecular evidences underlining the wide pharmacological spectrum of dopamine agonists currently used for treating Parkinsons disease patients. In particular, the mechanism of action of different dopamine agonists does not always appear to be restricted to the stimulation of selective dopamine receptor subtypes since at least some of these drugs are endowed with antioxidant, antiapoptotic or neurotrophic properties. These neuroprotective activities are molecule-specific and may contribute to the clinical efficacy of these drugs for the treatment of chronic and progressive neurodegenerative diseases in which oxidative injury and/or protein misfolding and aggregation exert a primary role.

Keywords: Free radicals, oxidative stress, Parkinson's disease, Alzheimer's disease, beta amyloid, neurodegeneration, fibrils, neurotrophic factors, neurogenesis