Avaliação dos efeitos comportamentais, neuroquímicos e imunohistoquímicos de Myracrodruon urundeuva Fr. All em modelo experimental de doença de Parkinson

Abstract

Parkinson's disease (PD) is the second most common neurodegenerative disorder being characterized by dopaminergic depletion in the nigrostriatal pathway. The pharmacological treatment of PD is palliative care, besides presenting a disabling adverse reaction profile. Neuroinflammation and oxidative stress (OE) are involved in the pathophysiology of PD and are important targets for treatments through neuroprotection. Myracrodroun urundeuva (MU) has secular and widespread use in the Brazilian northeast due to its remarkable anti-inflammatory and antioxidant properties. In the present study, we evaluated the effect of the liquid hydralcohol extracts (EHAMU: 5, 10, 20 and 40mg / kg) and dry (ESMU: 10 and 20 mg / kg) MU for 15 days orally in the experimental model of induced PD By unilateral striatal injection of 6-Hydroxydopamine. In the open field test, no changes were observed in the animal movement, however, in the Rota Rod test, an improvement in the motor coordination was observed in animals submitted to striatal lesion and treated with EHAMU at doses of 10, 20 and 40 mg / kg And with ESMU at doses of 10 and 20 mg / kg. In the apomorphine-induced rotational test, EHAMU and ESMU at a dose of 20mg / kg reduced the number of contralateral rotations in animals with unilateral striatal lesion by 77.8% and 86.2%, respectively, in the same dose as the liquid and dry extracts Were able to revert the striatal dopaminergic depletion by 71.7% and 100%, respectively, indicating an optimal neuroprotective effect of the plant, which was confirmed by Nissl staining and by immunocytochemistry for tyrosine hydroxylase performed on the injured striatal tissue. The antioxidant effect of the drug was evidenced in the in vitro test of DPPH where the dry extract at 25μg / ml had a similar effect to the control (vitamin E). We observed that the antioxidant effect of the extracts tested was not related to the ability to sequester superoxide oxidase by the in vitro superoxide dismutase test. The anti-inflammatory and antinociceptive potential of the extracts were also clearly observed in the paw edema models induced by carrageenan and Hargreaves, respectively, with significant results at doses of 10 and 20mg / kg. We also evaluated its action on neuroinflammation by means of immunohistochemistry for COX-2, iNOS, TNF-α in the cortex, striatum and CA1, CA3 regions to verify the neuroprotection mechanism of EHAMU (20 and 40mg / kg, vo - 15 days) And hippocampal parahippocampal gyrus, with the exception of the CA1 region, a significant decrease in tissue marking for these inflammation markers indicating a neuroprotection mechanism for both the striatal dopaminergic neurons and cortical and hippocampal neurons involved in dementia presented by patients with The disease in more advanced stages. In the striatal tissue, we also observed a dramatic decrease in NF-κB transcription factor labeling in animals treated with EHAMU (20 and 40mg / kg, v.o-15 days). We observed that EHAMU at a dose of 40mg / kg decreased the microglial activation by means of a marked decrease in the marking for OX-42, as well as the decrease in astrogliosis observed by the GFAP insipient marking in the striatum submitted to the lesion. MU therefore represents a viable and efficient option of neuropathy, presenting results that encourage clinical studies so that a new therapeutic strategy emirates not as a mere palliative but as a therapy that decreases or at least slows the progression of the disease .