RESUMO
The objective of this study was to investigate the activity of acetylcholinesterase (AChE), nitrite/nitrate (NOx) levels, as well as the biomarkers of cellular damage in the brain of mice experimentally infected with Toxoplasma gondii. Sixty mice were divided into two experiments: in experiment I the mice were infected with T. gondii/RH strain, while in experiment II they were infected with T. gondii, strains VEG and ME-49. Our evaluations were carried out on brain homogenized samples, assessing the AChE and glutathione reductase (GR) activities, and NOx, TBARS and AOPP levels in all the infected animals, compared with the control group. In both experiments, I and II, it was observed an increase in the activity of AChE and GR, as well as in the levels of NOx in the brain of infected mice with T. gondii. TBARS levels were increased in mice infected with the three different strains, RH, ME-49, and VEG. AOPP concentration was increased only in mice infected with the RH strain. Animals infected with the strains VEG and ME-49 showed histological lesions, associated with the presence of the parasite in the brain. Therefore, the infection by T. gondii is able to interfere in cholinesterase activity and NO levels, in association with oxidative stress and histological lesion.
Assuntos
Acetilcolinesterase/metabolismo , Encéfalo/metabolismo , Óxido Nítrico/metabolismo , Toxoplasmose Animal/metabolismo , Toxoplasmose Cerebral/metabolismo , Animais , Encéfalo/patologia , Masculino , Camundongos , Estresse Oxidativo , Toxoplasma , Toxoplasmose Animal/patologia , Toxoplasmose Cerebral/patologiaRESUMO
AIM: The purpose of this study was to investigate whether the flavonoid quercetin can prevent alterations in the behavioral tests and of cholinergic neurotransmission in rats submitted to the ethidium bromide (EB) experimental demyelination model during events of demyelination and remyelination. MAIN METHODS: Wistar rats were randomly distributed into four groups (20 animals per group): Control (pontine saline injection and treatment with ethanol), Querc (pontine saline injection and treatment with quercetin), EB (pontine 0.1% EB injection and treatment with ethanol), and EB+Querc (pontine 0.1% EB injection and treatment with quercetin). The groups Querc and Querc+EB were treated once daily with quercetin (50mg/kg) diluted in 25% ethanol solution (1ml/kg) and the animals of the control and EB groups were treated once daily with 25% ethanol solution (1ml/kg). Two stages were observed: phase of demyelination (peak on day 7) and phase of remyelination (peak on day 21 post-injection). Behavioral tests (beam walking, foot fault and inclined plane test), acetylcholinesterase (AChE) activity and lipid peroxidation in pons, cerebellum, hippocampus, hypothalamus, striatum and cerebral cortex were measured. KEY FINDINGS: The quercetin promoted earlier locomotor recovery, suggesting that there was demyelination prevention or further remyelination velocity as well as it was able to prevent the inhibition of AChE activity and the increase of lipidic peroxidation, suggesting that this compound can protect cholinergic neurotransmission. SIGNIFICANCE: These results may contribute to a better understanding of the neuroprotective role of quercetin and the importance of an antioxidant diet in humans to provide benefits in neurodegenerative diseases such as MS.