Resumo:
Parkinson's disease (PD) is a public health problem that affects many individuals in the
world, including Brazil. It is a neurodegenerative disease of slow progression that
mainly affects the elderly population. Although scientific research has advanced in
order to seek effective treatments for this pathology, there is no therapy capable of
curing or inhibiting the progression of the disease. The scientific community has been
prospecting neuroprotective compounds, which inhibit dysfunctions and death in cells
involved in PD pathogenesis; among them, it is possible to cite the flavonoid rutin,
which has had neuroprotective potential against glutamatergic excitotoxicity and
cytotoxicity induced by 6-hydroxydopamine. However, the lack of information on the
disease's etiology makes difficult advances in the discovery of new drugs to treat PD.
An important change that precedes the classic motor symptoms of PD is the disorder
in gastrointestinal motility, associated with changes in the enteric nervous system,
which also has an unknown etiology. In vitro and in vivo study models have revealed
that many cellular and molecular changes present in patients with the disease are
related to aminochrome toxicity, a compound derived from dopamine and precursor of
neuromelanine, present in remnant dopaminergic neurons. However, there is still no
report that it is able to induce changes in the enteric function. The overall objective of
this project was to evaluate the effect of rutin in Wistar rats with damage induced by
aminochrome in terms of: 1- levels of dopaminergic neuron marker expression
(tyrosine hydroxylase) in the ventral tegmental area (VTA) and substantia nigra pars
compacta (SNpc) and 2- gastrointestinal traffic time. The animals were randomized in
four groups: control group (CTR), aminochrome (AMI), rutin (RUT) and aminochrome
+ rutin (AMI+RUT). Rutin was administered by gavage, from the first to the twentieth
first day after stereotaxis. The living weight of the animals was evaluated from the day
of stereotaxic surgery until the time of perfusion. Intestinal transit time was evaluated
by the carmine red test, aiming to analyze the functional changes induced by the
treatments. As a result, rutin promoted a reduction in intestinal timely time compared
to the control group. The aminochrome also reduced the expression of tyrosine
hydroxylase (TH+) on the ipsilateral side of the SNpc, which was prevented by rutin
treatment. However, no change in TH+ expression in VTA of animals treated with
aminochrome and/or rutin was observed. Rutin promoted a reduction in the weight of
treated animals, with a modulatory role in weight regulation. Thus, studies are
necessary to evaluate the incited biochemical mechanisms for such modulation, which
is important for further research using preclinical DP models.
