Investigação do efeito protetor da creatina sobre alterações na memória de Drosophila melanogaster expostas a uma dieta rica em gordura vegetal hidrogenada

Abstract

The high consumption of ultra-processed food products is associated with an increase in the consumption of trans fatty acids. The type of fat ingested through food can influence brain performance, as the membrane that surrounds neuronal cells and accelerates the conduction of nerve impulses is rich in cholesterol and phospholipids. Therefore, trans fatty acids from the diet can be incorporated into this structure and promote changes, affecting learning and memory ability. Creatine is a nitrogenous compound produced by the body and also gained by food and/or supplementation. The compound acts as an energy reserve for the brain, as the enzyme creatine kinase, responsible for catalyzing the conversion of creatine to phosphocreatine and adenosine diphosphate, is present in several areas of this tissue and, therefore, acts on the reduction of mental fatigue to improve learning and memory performance. Thus, this study aimed to investigate the protective effect of creatine on changes in the memory of Drosophila melanogaster exposed to a diet rich in hydrogenated vegetable fat. Drosophila melanogaster flies (Harwich strain), 1-3 days old were divided into four groups containing about 50 flies each: (1) Regular diet, (2) 10 mM Creatine, (3) 10% Hydrogenated vegetable fat, (4) 10% Hydrogenated vegetable fat + 10 mM Creatine. Both creatine and fat were incorporated into the animals' diet. Exposure to the requirements lasts 7 days and after that period, an open field behavioral test was carried out, with the objective of evaluating the locomotor activity of the flies; mortality analysis; body weight; food consumption; and the aversive phototoxic suppression test, in order to assess the animal's learning and short-term memory. Based on the results, it was possible to observe that there was no significant difference in the open field test between all imposed groups. The same result was observed on the analysis of body weight and food consumption. Regarding the mortality analysis, it was observed that the diet rich in hydrogenated vegetable fat increased the mortality of flies and creatine did not have a protective effect. Regarding the aversive phototoxic suppression test, it was possible to observe that the flies exposed to a diet rich in hydrogenated vegetable fat had a lower percentage of approval for learning and memory. Treatment with creatine proved to be effective in preventing cognitive damage, suggesting its involvement in synapsis processes and cerebral energy homeostasis, in addition to its role in regulating the speed of action potentials and in intracellular communication using for learning and memory processes. It was concluded that creatine is able to protect against damage in learning and memory caused by a diet rich in hydrogenated vegetable fat in Drosophila melanogaster, however, further studies are still needed to elucidate the main action mechanisms involved.