Efeitos de dieta hipercalórica sobre os aspectos de depressão e ansiedade em ratos

Abstract

The accumulation of adipose tissue, caused by the consumption of hypercaloric foods, generates dysfunctions of the endocrine system, which affects, for example, the expression of brain-derived neurotrophic factor (BDNF). Cognitive and emotional changes, such as depression and anxiety, are diseases associated with BDNF levels. Thus, the objective of this work was to verify the effect of a hypercaloric diet on mood disorders - depression and anxiety - and the expression of BDNF in the hippocampus of young rats. All procedures were approved by the UNIPAMPA Ethics Committee under number 039/2017. In total, 20 Wistar rats (8 weeks old) were used. The animals were divided into two groups: control diet - which received industrial ration; and Diet High-Fat (HD) - which received ration with lard of pig and soybean oil. After 45 days of diet, the levels of obesity, adiposity, serum total cholesterol, low density liprotein (LDL), high density lipoprotein (HDL), triglycerides and glucose levels were evaluated; forced swimming test; high labyrinth; and expression of BDNF in the hippocampus by ELISA immunoassay. As a result, we verified that the control group increased their weight significantly over the weeks in relation to the HD group. However, the HD group had a higher concentration of adipose tissue, with a high adiposity index in relation to the control group. Blood biochemical parameters showed significantly higher values in HD animals. In addition, the HD group showed reduction of BDNF expression in the hippocampus. In addition, the animals in the HD group showed increased immobility time in the forced swimming test, as well as reduction of the time of permanence of the animals in the open arms and the number of open arms entrances, both in the high cross maze test. This study demonstrated that the hypercaloric diet induced an increase in the concentration of adipose tissue, which may be associated with reduced BDNF expression in the hippocampus, promoting behavioral changes of depressive and anxiety aspects in obese animals.