Disfun??o cognitiva canina: estudo de novas abordagens terap?uticas e diagn?sticas para a patologia e contribui??es a pesquisas direcionadas ao Mal de Alzheimer

• Autor(a) principal: Silva, Soraia John da
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/5295
• topic: Anticolinester?sicos; Biomarcadores; Disfun??o cognitiva; Anticholinesterases; Biomarkers; Cognitive dysfunction; Qu?mica

Canine Cognitive Dysfunction (CCD) is a neurodegenerative disorder that affects older dogs and it is very similar to Alzheimer's Disease (AD) in humans. Both pathologies are considered multifactorial and present evidence of b-amyloid deposition; oxidative stress; hyperphosphorylation of Tau protein; imbalance in neurotransmitter levels, such as acetylcholine (ACh) among other factors. Since ACh plays a key role in cognitive processes, this work aimed to evaluate the effect of DCC on enzymes that degrade Ach, also known as cholinesterases, and two enzymes of the antioxidant system: catalase and glutathione S-transferase. Thus, blood samples from 48 dogs divided into 5 groups were evaluated: control, risk group, mild DCC, moderate DCC, severe DCC. This aforementiones part of the paper composes chapter 1 of this thesis. Although there was no significant difference between the activities of these enzymes in the five groups studied, it was possible to observe changes in the average activities of cholinesterases (using acetylthiocholine as substrate), catalase and GST. These differences show that although such enzymes are not shown to be suitable as CCD biomarkers, they may in future be used as adjuvants in the analysis of disease evolution and in the assessment of response to treatment used. Since many AD treatments are based on the use of acetylcholinesterase inhibitors (AChE), this work also aimed to evaluate the efficacy of infusions, phytochemicals and synthetic compounds in the in vitro inhibition of this enzyme in dog?s brain. This second part of the paper composes chapter 2 of this thesis. The infusion of Peumus boldus presented prominence in this study proving effective in the inhibition of this enzyme and with significant antioxidant potential. The phytochemical quercetin and synthetic compounds Cum3 and Cum4 have stood out as competitive inhibitors of AChE activity. The effect of these compounds, as well as of boldo infusion, on the serum activity of butyrylcholinesterase (BChE) in dogs was also evaluated. However, all treatments were more effective in inhibiting brain AChE activity than BChE activity in serum. Although the outcomes of this study are still initial, they are promising ones and can contribute to an advance in the studies of new forms of diagnosis and treatment of CCD