Associação de diosmina e hesperidina em modelo de hemiparkinsonismo induzido por 6-hidroxidopamina em ratos

Abstract

Parkinson's disease (PD) is one of the most common age-related neurodegenerative disorders, affecting millions of people worldwide. The disease is characterized by selective death of the dopaminergic neurons located in the substantia nigra pars compacta in the midbrain, resulting in motor dysfunction. Levodopa (L-DOPA) is still the "gold standard" drug for the dopamine replacement in PD, alleviating the motor symptoms of the disease. However, L-DOPA causes a series of collateral effects. Diosmin (DM) is an already marketed drug, composed of a purified flavonoic fraction, in micronized form of 90% diosmin and 10% hesperidin. It is used for the symptomatic treatment of symptoms related to Chronic Venous Insufficiency. Several studies confirm the antioxidant, anti-inflammatory, anticancer and neuroprotective activity of the components of this drug. In this context, the discovery of new drugs that may prevent the progression of PD and reduce the adverse effects of traditional treatments is necessary, so it was aimed to study the effects of diosmin alone or associated with L-DOPA in the experimental model of DP induced by 6-hydroxydopamine (6-OHDA). For this, unilateral 6-OHDA (21 μg/ animal) lesions in the right striatum were treated with DM (50, 100 and 200 mg/kg); L-DOPA (25 mg/kg) or DM 100 mg/kg in combination with L-DOPA 12.5 mg/kg for 14 days, starting 7 days post-surgery. On the 21st day, the animals were submitted to specific behavioral tests (Open field test, Rotarod and Rotational Test). After, the animals were sacrificed, and its brain areas were dissected for neurochemical analyzes (reduced glutathione, lipid peroxidation and nitrite). DM (100 mg/kg v.o.) was able to reverse motor deficits induced by 6-OHDA, as well as increased the levels of reduced glutathione (GSH) and substantially reduced nitrite / nitrate levels. In addition, the association of Diosmin with sub-dose of Levodopa showed some effects better than L-DOPA alone at a higher dose. Nevertheless, DM did not show modulation in the malondialdehyde levels in the brains areas from hemiparkinsonian’s animals. Thus, DM revealed a neuroprotective activity against motor and neurochemical disturbs in 6-OHDA-injured hemiparkinsonian rats. Additionally, our data suggest a possible efficiency in the association between DM with L-DOPA for treatment of motor deficit induced by 6-OHDA in rats.