Avaliação dos efeitos de uma dieta rica em sacarose sobre os comportamentos associados a neurodegeneração em Drosophila melanogaster

Abstract

The dysfunctions caused by the excessive consumption of hyperglycidic and / or biologically distorted diets in the long term promote the development of obesity, characterized as excessive accumulation of fat in the body and is related to the appearance of the metabolic syndrome and type II Diabetes mellitus (DM). DM is a risk factor for the development of other pathologies, such as Alzheimer's disease and Parkinson's disease. Several animal models have been used to study the mechanisms involved in metabolic syndromes and neurodegenerative diseases. Among these models we mention Drosophila melanogaster, known as the fruit fly. This animal has stood out due to the similarity between its endocrine system and that of mammals.Thus, this study aimed to evaluate the effects of a diet rich in sucrose on the behavior associated with neurodegeneration in flies. For this, the flies were fed a standardized diet, in different concentrations of sucrose, being: 5% sucrose (control), 10%, 20% and 40% sucrose. 300μl of the diet was offered daily for five days, using the Continuous Liquid Feeding (CLF) method. The data demonstrated that flies exposed to a high-glycemic diet had a reduced life span. Regarding the weight parameter, the flies had no changes. The diet caused an increase in the levels of glucose and triglycerides, in the whole body of the flies and also in the hemolymph and carcass of the animals. Also, the flies that were fed with concentrations of 40% sucrose showed high levels of oxidative stress. This change was also accompanied by significant depletion of dopamine levels in the heads of these animals. Our study also showed that flies exposed to the diet in the highest concentrations had sucrose deficits in locomotor and exploratory behavior. Thus, we consider that metabolic changes, such as increased levels of glucose and triglycerides, cause an increase in oxidative stress levels, which in turn lead to depletion of dopamine levels in the head of flies. We also believe that the reduction in dopamine levels possibly precedes the observed locomotor damage. Based on the above, our research contributes to other studies in order to understand the involvement of the metabolic syndrome and the emergence of neurological diseases. In order to elucidate this issue, we have the future perspective, 1: to evaluate some genes that are involved in insulin signaling, such as dilps (2, 3 and 5), CHICO, Inr; 2: to evaluate the toxicity of the hyperglycidic diet on inflammatory markers in Drosophila melanogaster and 3: to evaluate the repositioning of drugs in the treatment of type II DM.